Showing papers in "Chinese Science Bulletin in 2016"
TL;DR: Flavones of Scutellaria baicalensis Georgi are reported to have various pharmacological functions, including anti-cancer, hepatoprotection, antibacterial and antiviral, antioxidant, anticonvulsant and neuroprotective effects.
Abstract: Scutellaria baicalensis Georgi, or Chinese skullcap, has been widely used as a medicinal plant in China for thousands of years, where the preparation from its roots is called Huang-Qin. It has been applied in the treatment of diarrhea, dysentery, hypertension, hemorrhaging, insomnia, inflammation and respiratory infections. Flavones such as baicalin, wogonoside and their aglycones baicalein wogonin are the major bioactive compounds extracted from the root of S. baicalensis. These flavones have been reported to have various pharmacological functions, including anti-cancer, hepatoprotection, antibacterial and antiviral, antioxidant, anticonvulsant and neuroprotective effects. In this review, we focus on clinical applications and the pharmacological properties of the medicinal plant and the flavones extracted from it. We also describe biotechnological and metabolic methods that have been used to elucidate the biosynthetic pathways of the bioactive compounds in Scutellaria.
292 citations
TL;DR: A systematic review of urban growth models, including the evolution of urban models and associated theories and the common framework of different models and their applications, is provided.
Abstract: Urban growth models have been developed and extensively adopted to study urban expansion and its impact on the ambient environment. These models can be employed in urban policymaking or analyses of development scenarios. In this paper, we provide a systematic review of urban growth models, including the evolution of urban models and associated theories and the common framework of different models and their applications. Three typical classes of urban growth models, namely, the land use/transportation model, the cellular automata (CA) model and the agent-based model, were introduced. Their relationships were explained, considering their modelling mechanisms, data requirements and application scales. Based on the extensively utilized urban CA models, we proposed four perspectives for improvements, including the adjustment of the basic spatial unit, the incorporation of temporal contexts, public platforms to support model comparison, and scenario analyses. New opportunities (e.g., open social data and integrated assessment models) have emerged to assist model development and application.
129 citations
TL;DR: In this paper, the feasibility of using borophene, a newly synthesized two-dimensional sheet of boron, as an anode material for sodium-ion and sodium-oxygen batteries was investigated.
Abstract: Density functional theory calculations and ab initio molecular dynamics simulations are performed to study the feasibility of using borophene, a newly synthesized two-dimensional sheet of boron, as an anode material for sodium-ion and sodium-oxygen batteries. The theoretical capacity of borophene is found to be as high as 1,218 mAh g -1 (Na 0.5 B). More importantly, it is demonstrated that the sodium diffusion energy barrier along the valley direction is as low as 0.0019 eV, which corresponds to a diffusivity of more than a thousand times higher than that of conventional anode materials such as Na 2 Ti 3 O 7 and Na 3 Sb. Hence, the use of borophene will revolutionize the rate capability of sodium-based batteries. Moreover, it is predicted that, during the sodiation process, the average open-circuit voltage is 0.53 V, which can effectively suppress the formation of dendrites while maximizing the energy density. The metallic feature and structural integrity of borophene can be well preserved at different sodium concentrations, demonstrating good electronic conductivity and stable cyclability.
110 citations
TL;DR: In this paper, the authors proposed a method to identify the most important features of a person's personality and personality type. But they did not specify the characteristics of the personality type of the person.
Abstract: 薛定谔猫的假想实验展示了量子力学的奇异性质并引起了广泛兴趣.我们提出把一个低温冷冻保存的微生物放在一个电机械振子上来实现活体微生物的量子态叠加, 纠缠和隐形传态. 目前,实验上已经把一个直径15微米的电机械振子的质心运动冷却到量子基态[Nature 475:359 (2011)], 并和微波光子纠缠[Science 342: 710 (2013)]. 把一个质量远小于电机械振子的微生物放在振子上面不会对它的性质和量子操控造成显著影响. 这个微生物可以和振子共同冷却到量子基态并制备到叠加态. 利用一个强磁场梯度,微生物的内部状态(比如甘氨酸自由基的电子自旋)可以和微生物的质心运动纠缠, 并被量子隐形传态到另外一个微生物. 因为微生物的内部状态包含信息, 这个方案能实现两个微生物之间信息和记忆的量子隐形传态.这篇论文也提供了一个达到量子极限的磁共振力学显微镜方案
105 citations
TL;DR: In this paper, the efficient elimination of radionuclides using GOs and GO-based nanomaterials as adsorbents are summarized and the interaction mechanisms are discussed from the results of batch techniques, surface complexation modeling, spectroscopic analysis and theoretical calculations.
Abstract: With the fast development of nanoscience and nanotechnology, the nanomaterials have attracted multidisciplinary interests. The high specific surface area and large numbers of oxygen-containing functional groups of graphene oxides (GOs) make them suitable in the preconcentration and solidification of radionuclides from wastewater. In this paper, mainly based on the recent work carried out in our laboratory, the efficient elimination of radionuclides using GOs and GO-based nanomaterials as adsorbents are summarized and the interaction mechanisms are discussed from the results of batch techniques, surface complexation modeling, spectroscopic analysis and theoretical calculations. This review is helpful for the understanding of the interactions of radionuclides with GOs and GO-based nanomaterials, which is also crucial for the application of GOs and GO-based nanomaterials in environmental radionuclide pollution management and also helpful in nuclear waste management.
103 citations
TL;DR: This article reviews recent advances in the elucidation of biosynthesis of specialized metabolites in medicinal plants, including phenylpropanoids, terpenoids and alkaloids, focusing on traditional Chinese medicine.
Abstract: Plants synthesize and accumulate large amount of specialized (or secondary) metabolites also known as natural products, which provide a rich source for modern pharmacy. In China, plants have been used in traditional medicine for thousands of years. Recent development of molecular biology, genomics and functional genomics as well as high-throughput analytical chemical technologies has greatly promoted the research on medicinal plants. In this article, we review recent advances in the elucidation of biosynthesis of specialized metabolites in medicinal plants, including phenylpropanoids, terpenoids and alkaloids. These natural products may share a common upstream pathway to form a limited numbers of common precursors, but are characteristic in distinct modifications leading to highly variable structures. Although this review is focused on traditional Chinese medicine, other plants with a great medicinal interest or potential are also discussed. Understanding of their biosynthesis processes is critical for producing these highly value molecules at large scale and low cost in microbes and will benefit to not only human health but also plant resource conservation.
102 citations
TL;DR: CoFe2O4 as mentioned in this paper has a 3.35% success rate in the last three months of 2016, and 3.5% in the first two months of 2017.
Abstract: 光生载流子分离和表面催化反应是光催化分解水制氢过程的2个主要步骤,协同提高这两步速率必然能极大促进催化剂的制氢效率。本文以g-C3N4为研究对象,通过负载铁酸盐CoFe2O4或NiFe2O4,g-C3N4的光催化制氢性能得到大幅提高。研究结果表明,(Co, Ni)Fe2O4不仅能够有效地促进g-C3N4中的光生载流子的分离,而且能够有效地促进表面催化氧化半反应;与此同时,负载Pt作为产氢助催化剂,能促进表面催化还原产氢半反应。在光催化反应中,g-C3N4中的光生电子和空穴分别流向Pt和(Co, Ni)Fe2O4,电子在Pt上还原反应产生氢气,而空穴转移到(Co, Ni)Fe2O4上与牺牲剂反应。进一步研究结果发现,CoFe2O4对g-C3N4的载流子分离与氧化半反应催化效果均优于NiFe2O4。通过CoFe2O4和Pt共负载,Pt/g-C3N4/CoFe2O4光催化剂的催化制氢量子效率在420 nm处达到3.35 %,在可见光区(λ > 420 nm)的光催化制氢速率是未负载铁酸盐的Pt/g-C3N4的3.5倍。
92 citations
TL;DR: In this paper, a mesoscopic model has been established to investigate the thermodynamic mechanisms and densification behavior of nickel-based superalloy during additive manufacturing/three-dimensional (3D) printing (AM/3DP) by numerical simulation, using a finite volume method.
Abstract: A mesoscopic model has been established to investigate the thermodynamic mechanisms and densification behavior of nickel-based superalloy during additive manufacturing/three-dimensional (3D) printing (AM/3DP) by numerical simulation, using a finite volume method (FVM). The influence of the applied linear energy density (LED) on dimensions of the molten pool, thermodynamic mechanisms within the pool, bubbles migration and resultant densification behavior of AM/3DP-processed superalloy has been discussed. It reveals that the center of the molten pool slightly shifts with a lagging of 4 μm towards the center of the moving laser beam. The Marangoni convection, which has various flow patterns, plays a crucial role in intensifying the convective heat and mass transfer, which is responsible for the bubbles migration and densification behavior of AM/3DP-processed parts. At an optimized LED of 221.5 J/m, the outward convection favors the numerous bubbles to escape from the molten pool easily and the resultant considerably high relative density of 98.9 % is achieved. However, as the applied LED further increases over 249.5 J/m, the convection pattern is apparently intensified with the formation of vortexes and the bubbles tend to be entrapped by the rotating flow within the molten pool, resulting in a large amount of residual porosity and a sharp reduction in densification of the superalloy. The change rules of the relative density and the corresponding distribution of porosity obtained by experiments are in accordance with the simulation results.
91 citations
TL;DR: The pairing mechanism of high-temperature superconductivity in cuprates remains the biggest unresolved mystery in condensed matter physics as mentioned in this paper, and one of the most effective approaches is to investigate directly the superconducting CuO2 layers.
Abstract: The pairing mechanism of high-temperature superconductivity in cuprates remains the biggest unresolved mystery in condensed matter physics. To solve the problem, one of the most effective approaches is to investigate directly the superconducting CuO2 layers. Here, by growing CuO2 monolayer films on Bi2Sr2CaCu2O8+δ substrates, we identify two distinct and spatially separated energy gaps centered at the Fermi energy, a smaller U-like gap and a larger V-like gap on the films, and study their interactions with alien atoms by low-temperature scanning tunneling microscopy. The newly discovered U-like gap exhibits strong phase coherence and is immune to scattering by K, Cs and Ag atoms, suggesting its nature as a nodeless superconducting gap in the CuO2 layers, whereas the V-like gap agrees with the well-known pseudogap state in the underdoped regime. Our results support an s-wave superconductivity in Bi2Sr2CaCu2O8+δ , which, we propose, originates from the modulation-doping resultant two-dimensional hole liquid confined in the CuO2 layers.
88 citations
TL;DR: In this article, the first numerically-exact sign-problem-free quantum Monte Carlo simulations to iron-based superconductors were performed, and the effects of electron-phonon interaction between FeSe and STO as well as nematic fluctuations on superconducting gap-opening temperatures were investigated.
Abstract: Monolayer FeSe films grown on SrTiO3 (STO) substrate show superconducting gap-opening temperatures ([Formula: see text]) which are almost an order of magnitude higher than those of the bulk FeSe and are highest among all known Fe-based superconductors. Angle-resolved photoemission spectroscopy observed "replica bands" suggesting the importance of the interaction between FeSe electrons and STO phonons. These facts rejuvenated the quest for [Formula: see text] enhancement mechanisms in iron-based, especially iron-chalcogenide, superconductors. Here, we perform the first numerically-exact sign-problem-free quantum Monte Carlo simulations to iron-based superconductors. We (1) study the electronic pairing mechanism intrinsic to heavily electron doped FeSe films, and (2) examine the effects of electron-phonon interaction between FeSe and STO as well as nematic fluctuations on [Formula: see text]. Armed with these results, we return to the question "what makes the [Formula: see text] of monolayer FeSe on SrTiO3 so high?" in the conclusion and discussions.
83 citations
TL;DR: In this article, a review of the constant-volume propagating spherical flame method for laminar flame speed measurement is presented, where the authors discuss the sources of discrepancies in the results obtained by different groups for the same mixture.
Abstract: Laminar flame speed is one of the most important intrinsic properties of a combustible mixture. Due to its importance, different methods have been developed to measure the laminar flame speed. This paper reviews the constant-volume propagating spherical flame method for laminar flame speed measurement. This method can be used to measure laminar flame speed at high pressures and temperatures which are close to engine-relevant conditions. First, the propagating spherical flame method is introduced and the constant-volume method (CVM) and constant-pressure method (CPM) are compared. Then, main groups using the constant-volume propagating spherical flame method are introduced and large discrepancies in laminar flame speeds measured by different groups for the same mixture are identified. The sources of discrepancies in laminar flame speed measured by CVM are discussed and special attention is devoted to the error encountered in data processing. Different correlations among burned mass fraction, pressure, temperature and flame speed, which are used by different researchers to obtain laminar flame speed, are summarized. The performance of these correlations are examined, based on which recommendations are given. Finally, recommendations for future studies on the constant-volume propagating spherical flame method for laminar flame speed measurement are presented.
TL;DR: In this paper, a simple electrospinning method in which few-single-layer WS2 is uniformly embedded in carbon fibers was used to obtain a first-cycle discharge/charge capacity of 941/756 mAh/g at 100 mA/g and maintain a capacity of 458 m Ah/g after 100 cycles at 1 A/g.
Abstract: WS2/carbon nanofibers (WS2/CNFs) are obtained by a simple electrospinning method in which few-/single-layer WS2 is uniformly embedded in carbon fibers. When used as the active anode material for Li-ion cells, these nanofibers exhibit a first-cycle discharge/charge capacity of 941/756 mAh/g at 100 mA/g and maintain a capacity of 458 mAh/g after 100 cycles at 1 A/g. The evolution of size and crystallinity of WS2 with heating treatment are systematically studied, which are found to strongly influence the final electrochemical performance. Interestingly, the WS2 samples of lowest crystallinity show the highest performance among all studied samples, which could result from the large interfacial capacity for Li ions due to their large specific surface area. More interestingly, the inherent flexible attribute of electrospun nanofibers renders them a great potential in the utilization of binder-free anodes. Similar high discharge/charge capacity of 761/604 mAh/g with a first coulombic efficiency of 79.4 % has been achieved in these binder-free anodes. Considering the universal of such simple and scalable preparation strategy, it is very likely to extend this method to other similar two-dimensional layered materials besides WS2 and provides a promising candidate electrode for developing flexible battery devices.
TL;DR: Optical microcavities have attracted strong research interests, for their unique property of confining photons for a long time in small volumes, which significantly enhances light-matter interaction as discussed by the authors.
Abstract: Optical microcavities have attracted strong research interests,for their unique property of confining photons for a long time in small volumes,which significantly enhances light–matter interaction[1].In recent decades,various fabrication techniques of microcavities with higher quality factors(Q)and smaller mode volumes(V_m)have been developed,pushing forward studies from fundamental physics to functional photonics devices.Microcavity optomechanics provides an ideal platform for exploring the quantum nature of macroscopic objects[2],quantum
TL;DR: In this paper, a grid-based spatially explicit cellular automata (CA) model is proposed for downscaling coarse-resolution land use scenarios to finer (i.e., 1 km) resolutions at the global scale.
Abstract: Global climate and environmental change studies require detailed land-use and land-cover (LULC) information about the past, present, and future. In this paper, we discuss a methodology for downscaling coarse-resolution (i.e., half-degree) future land use scenarios to finer (i.e., 1 km) resolutions at the global scale using a grid-based spatially explicit cellular automata (CA) model. We account for spatial heterogeneity from topography, climate, soils, and socioeconomic variables. The model uses a global 30 m land cover map (2010) as the base input, a variety of biogeographic and socioeconomic variables, and an empirical analysis to downscale coarse-resolution land use information (specifically urban, crop and pasture). The output of this model offers the most current and finest-scale future LULC dynamics from 2010 to 2100 (with four representative concentration pathway (RCP) scenarios-RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5) at a 1 km resolution within a globally consistent framework. The data are freely available for download, and will enable researchers to study the impacts of LULC change at the local scale.
TL;DR: In this paper, an intermediate coupled model (ICM) is used at the Institute of Oceanology, Chinese Academy of Sciences (IOCAS), named the IOCAS ICM, to predict the sea surface temperature (SST) evolution in the tropical Pacific during the 2015-2016 El Nino event.
Abstract: The tropical Pacific is currently experiencing an El Nino event. Various coupled models with different degrees of complexity have been used to make real-time El Nino predictions, but large uncertainties exist in the intensity forecast and are strongly model dependent. An intermediate coupled model (ICM) is used at the Institute of Oceanology, Chinese Academy of Sciences (IOCAS), named the IOCAS ICM, to predict the sea surface temperature (SST) evolution in the tropical Pacific during the 2015–2016 El Nino event. One unique feature of the IOCAS ICM is the way in which the temperature of subsurface water entrained in the mixed layer (Te) is parameterized. Observed SST anomalies are only field that is utilized to initialize the coupled prediction using the IOCAS ICM. Examples are given of the model’s ability to predict the SST conditions in a real-time manner. As is commonly evident in El Nino-Southern Oscillation predictions using coupled models, large discrepancies occur between the observed and predicted SST anomalies in spring 2015. Starting from early summer 2015, the model can realistically predict warming conditions. Thereafter, good predictions can be made through the summer and fall seasons of 2015. A transition to normal and cold conditions is predicted to occur in late spring 2016. Comparisons with other model predictions are made and factors influencing the prediction performance of the IOCAS ICM are also discussed.
TL;DR: In this paper, the microscopic features of the microplastic surfaces were characterized using a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS).
Abstract: Microplastics ( - 3) followed by visual selection. All the microplastics were photographed and image analysis was performed using the program Nano Measurer 1.2 for counting and size measurement. The microscopic features of the microplastic surfaces were characterized using a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS).
TL;DR: This review article will refresh classification of trichomes in A. annua, and propose new avenues to increase artemisinin yield by harnessing the potential biofactories, AaGSTs.
Abstract: Artemisinin, the key ingredient of first-line antimalarial drugs, has large demand every year. The native plant, which produces small quantities of artemisinin, remains as its main source and thus results in a short supply of artemisinin. Intensified efforts have been carried out to elevate artemisinin production. However, the routine metabolic engineering strategy, via overexpressing or down-regulating genes in artemisinin biosynthesis branch pathways, was not very effective as desired. Glandular secretory trichomes, sites of artemisinin biosynthesis on the surface of Artemisia annua L. (A. annua), are the new target for increasing artemisinin yield. In general, the population and morphology of glandular secretory trichomes in A. annua (AaGSTs) are often positively correlated with artemisinin content. Improved understanding of AaGSTs will shed light on the opportunities for increasing plant-derived artemisinin. This review article will refresh classification of trichomes in A. annua and provide an overview of the recent achievements regarding AaGSTs and artemisinin. To have a full understanding of AaGSTs, factors that are associated with trichome morphology and density will have to be further investigated, such as genes, microRNAs and phytohormones. The purpose of this review was to (1) update the knowledge of the relation between AaGSTs and artemisinin, and (2) propose new avenues to increase artemisinin yield by harnessing the potential biofactories, AaGSTs.
TL;DR: Wang et al. as discussed by the authors analyzed the development of Earth observation technology and big data, explored the concepts and scientific connotations of Big Earth Data from space, discussed the correlation between big Earth Data and Digital Earth, and dissected the potential of big earth data from space to promote scientific discovery in the Earth sciences, especially concerning global changes.
Abstract: Big data is a strategic highland in the era of knowledge-driven economies, and it is also a new type of strategic resource for all nations. Big data collected from space for Earth observation—so-called Big Earth Data—is creating new opportunities for the Earth sciences and revolutionizing the innovation of methodologies and thought patterns. It has potential to advance in-depth development of Earth sciences and bring more exciting scientific discoveries. The Academic Divisions of the Chinese Academy of Sciences Forum on Frontiers of Science and Technology for Big Earth Data from Space was held in Beijing in June of 2015. The forum analyzed the development of Earth observation technology and big data, explored the concepts and scientific connotations of Big Earth Data from space, discussed the correlation between Big Earth Data and Digital Earth, and dissected the potential of Big Earth Data from space to promote scientific discovery in the Earth sciences, especially concerning global changes.
TL;DR: Even-MIF was reported in natural samples mainly related to the atmosphere as discussed by the authors, and was thought to be caused by either nuclear volume effect or magnetic isotope effect, but the exact mechanism triggering significant even Hg isotope anomaly is still unclear.
Abstract: Practically all physical, chemical, and biological processes can induce mass-dependent fractionation of mercury (Hg) isotopes. A few special processes such as photochemical reduction of Hg(II) and photochemical degradation of methylmercury (MeHg) can produce mass-independent fractionation (MIF) of odd Hg isotopes (odd-MIF), which had been largely reported in variable natural samples and laboratory experiments, and was thought to be caused by either nuclear volume effect or magnetic isotope effect. Recently, intriguing MIF of even Hg isotopes (even-MIF) had been determined in natural samples mainly related to the atmosphere. Though photo-oxidation in the tropopause (inter-layer between the stratosphere and the troposphere) and neutron capture in space were thought to be the possible processes causing even-MIF, the exact mechanism triggering significant even Hg isotope anomaly is still unclear. Even-MIF could provide useful information about the atmospheric chemistry and related climate changes, and the biogeochemical cycle of Hg.
TL;DR: This study shows that it is possible to design interconnects for an optimum thermal stress performance of the cell, and indicates that thermal stress of coflow design is smaller than that of counterflow, corresponding to the temperature distribution.
Abstract: The mechanical failure of solid oxide fuel cell (SOFC) components may cause cracks with consequences such as gas leakage, structure instability and reduction of cell lifetime. A comprehensive 3D model of the thermal stresses of an anode-supported planar SOFC is presented in this work. The main objective of this paper is to get an interconnect optimized design by evaluating the thermal stresses of an anode-supported SOFC for different designs, which would be a new criterion for interconnect design. The model incorporates the momentum, mass, heat, ion and electron transport, as well as steady-state mechanics. Heat from methane steam reforming and water–gas shift reaction were considered in our model. The results examine the relationship between the interconnect structures and thermal stresses in SOFC at certain mechanical properties. A wider interconnect of the anode side lowers the stress obviously. The simulation results also indicate that thermal stress of coflow design is smaller than that of counterflow, corresponding to the temperature distribution. This study shows that it is possible to design interconnects for an optimum thermal stress performance of the cell.
TL;DR: Porous N-doped carbon nanotubes (NCNTs) as mentioned in this paper were fabricated by KOH activation and pyrolysis of polypyrrole nano-notubes.
Abstract: Developing efficient metal-free bi-functional electrocatalysts is required to reduce costs and improve the slow oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics in electrochemical systems. Porous N-doped carbon nanotubes (NCNTs) were fabricated by KOH activation and pyrolysis of polypyrrole nanotubes. The NCNTs possessed a large surface area of more than 1,000 m2 g−1. NCNT electrocatalysts, particularly those annealed at 900 °C, exhibited excellent ORR electrocatalytic performance. Specifically, they yielded a more positive onset potential, higher current density, and long-term operation stability in alkaline media, when compared with a commercially available 20 wt% Pt/C catalyst. This resulted from the synergetic effect between the dominant pyridinic/graphitic-N species and the porous tube structures. The NCNT electrocatalyst also exhibited good performance for the OER. The metal-free porous nitrogen-doped carbon nanomaterials were prepared from low cost and environmentally friendly precursors. They are potential alternatives to Pt/C catalysts, for electrochemical energy conversion and storage.
TL;DR: The uniform design ray (UD-ray) integrating UD idea with fixed-ratio ray design can systematically and comprehensively measure the combined toxicity changes in the MCM system as mentioned in this paper.
Abstract: Multi-component mixture (MCM) is a complicated chemical system that contains a great deal of mixture rays with various mixture ratios, and each ray includes many mixtures with different concentration levels
. Currently, in combined toxicity field, almost all studies on MCM focus on the mixtures designed by the equivalent-effect concentration ratio (EECR) procedure. However, the EECR mixtures cannot represent the whole mixture system because the EECR mixtures are located on one mixture ray in concentration space formed by multiple components. In our view, some optimal experimental design such as the uniform design (UD) should be used to effectively select many representative mixture rays from the MCM system, instead of single EECR ray. The uniform design ray (UD-ray) integrating UD idea with fixed-ratio ray design can systematically and comprehensively measure the combined toxicity changes in the MCM system. This review introduces the operation method, construction of uniform table and corresponding usable table, and some cases of application of the UD-ray to help readers easily use UD-ray in their MCM toxicity assessment.
TL;DR: In this article, Liu et al. reported a robust coexistence of superconductivity and ferromagnetic superconductor in RbEuFe and showed that it is a new robust super-conductor.
Abstract: Superconductivity (SC) and ferromagnetism (FM) are in general antagonistic,
which makes their coexistence very rare. Following our recent discovery of robust coexistence of SC and FM in $$\hbox {RbEuFe}_4\hbox {As}_4$$
(Liu et al. in Phys Rev B 93:214503, 2016), here we report another example of such a coexistence in its sister compound $$\hbox {CsEuFe}_4\hbox {As}_4$$
, synthesized for the first time. The new material exhibits bulk SC at 35.2 K and $$\hbox {Eu}^{2+}$$
-spin ferromagnetic ordering at 15.5 K, demonstrating that it is a new robust ferromagnetic superconductor.
TL;DR: The review points out effective ways to inhibit hydrogen evolution and prolong the cycling life of advanced lead–acid battery, especially in high-rate partial-state-of-charge applications.
Abstract: Integrating high content carbon into the negative electrodes of advanced lead–acid batteries effectively eliminates the sulfation and improves the cycle life, but brings the problem of hydrogen evolution, which increases inner pressure and accelerates the water loss. In this review, the mechanism of hydrogen evolution reaction in advanced lead–acid batteries, including lead–carbon battery and ultrabattery, is briefly reviewed. The strategies on suppression hydrogen evolution via structure modifications of carbon materials and adding hydrogen evolution inhibitors are summarized as well. The review points out effective ways to inhibit hydrogen evolution and prolong the cycling life of advanced lead–acid battery, especially in high-rate partial-state-of-charge applications.
TL;DR: An unconventional way to cure peripheral nerve injury (PNI) with liquid metal gallium employed as the reconnection agent is demonstrated, which is expected to perform well in clinical surgery for PNI and even central nervous system injury in the coming time.
Abstract: This study demonstrated an unconventional way to cure peripheral nerve injury (PNI) with liquid metal gallium employed as the reconnection agent. In vivo experiments were performed, in which transected sciatic nerve of mouse was reconnected by liquid metal gallium. The nerve signals detected was found to be almost the same as those from the complete nerve, where the negative bursting firing caused by PNI was absent on the neural discharge curve after nerve-reconnection surgery. Meanwhile the atrophy tendency of gastrocnemius muscle was distinctly procrastinated according to the results of pathological examinations, which showed fibrillation potentials emerged immediately for mice with PNI but did not emerge until the third month for those received nerve-reconnection surgery. Furthermore, physical properties of gallium were studied, showing that its impedance was slightly influenced by the frequency of transmitted signal and the temperature, which confirmed the stability of gallium in future clinical usage. This technology is expected to perform well in clinical surgery for PNI and even central nervous system injury in the coming time.
TL;DR: There is no accurate estimate and the estimations of the total number of species on earth do not converge yet, however, the number ofspecies of higher plants, freshwater fishes, amphibians, reptiles, birds and mammals are relatively clearly ascertained.
Abstract: How many species are there in the marine or terrestrial realms in the world? Biologists have tried to answer this question for the past half century. However, different estimations are made of the number of species, using different methods, estimates range from 500000 to 100000000 species on earth. There is no accurate estimate and the estimations of the total number of species on earth do not converge yet. However, the number of species of higher plants, freshwater fishes, amphibians, reptiles, birds and mammals are relatively clearly ascertained. Most botanists agree there are 30000000– 3500000 plant species on earth. FishData (2016) reported 33200 fish species that have been scientifically described, of which 14000 are freshwater species. The American Museum of Natural History (2016) recorded 7493 amphibians in the world. Reptile Data Base (2016) recorded 10272 reptile species. BirdLife International (2016) reported 10426 bird species. Wilson and Reeder (2005) reported 5436 mammalian species in 2005. Adding the new species reported worldwide since then, IUCN (2016) reported there are 5515 mammalian species excluding domestic animals on earth. Why can we not get an accurate count of species number on earth? The reasons lie in differences in the definition of species, taxonomic methods, standards of species used by different taxonomists and the research scope and depth in different taxa or in different regions on earth. The species is a disputed concept, which has evolved since Darwin’s time, yet we still cannot reach a universal definition of the concept. In the past, taxonomists used morphorlogical traits to classify species, later numerical taxonomic methods and cladisitic methods were used. Now molecular phylogeny is widely in use in taxonomy, and more phylogenetic species are discovered with this method. Taxonomy is an empirical science. Taxonomists study different goups, and even different taxonomists studying the same group may hold different opinions on the standard of species, reflecting that often taxonomists cannot reach agreement on whether a species is valid, whether to split a species or to lump several taxa into a single species. Taxonomists have done siginficant work on describing species in mammals, birds, reptiles and amphibians, but little work on, e.g., nematodes. Most biodiversity studies are concentrated in deveploped countries like USA and UK while the biodoversity-rich counrties like Ecuador, Indonesia, Madagascar and Peru are neglected. Most leading biologistss are working in academic institutions and universities located in developed countries, who dominate the conservation science policy making bodies such as IUCN/SSC specialist groups, Red List Committee and IUCN Endangered Species Redlist Techanical Working Group (Wilson et al. 2016). Thus, most species remain undescribed. If one day, people can carry out thorough studies on all taxa in all habitats on earth when taxonomists studying different taxa cannot standardize their definition of species, or even taxonomists studying the same taxa cannot standardize their definition of species, we still cannot get an accurate census of number of species on the earth. Nevertheless, it would be logic to estimate the number of species on the earth.
TL;DR: Ionic liquids (ILs) have been widely used in various fields, such as electrocatalysis, the electrosynthesis, electrodeposition, electrochemical devices and sensors.
Abstract: Ionic liquids (ILs) have been generally described as molten salts which are composed of asymmetric cations and anions. They exist in liquid state below 100 °C. Both ILs and their composite materials have been widely used in various fields. Attributed to the outstanding properties including the thermal and chemical stabilities, the negligible volatility, the high ionic conductivity, the wide electrochemical window, and the easy design in the construction, ILs have been applied in electrochemical applications including the electrocatalysis, the electrosynthesis, the electrodeposition, the electrochamical devices and sensors. In addition to the application in electrochemical sensors, ILs have also been used in biosensors because of their biocompatibiciy. Here, we review the recent developments for the applicaitons of ILs in electrochemical sensors and biosensors, including the corresponding properties of ILs suitable for electrochemical sensors. Electrochemical biosensors constructed by numorous composites are the emphasis in the review.
TL;DR: In this paper, the authors introduce the recent progress of 2D/3D photonic crystals (RPCs) for visual detection of chemical and biological analytes, including the preparation of 3D PC films, 3DPC microbeads and their applications as visualized sensors.
Abstract: Responsive photonic crystals (RPCs) constructed by periodic two/three-dimensional (2D/3D) photonic crystals (PCs) and responsive-material hosts, are important visualized optical sensors. Their optical diffraction color can be tuned reversibly by external stimuli, such as pH, metal ions, biomolecules, vapors and solvents, hence leading to wide applications as visualized sensors. This review introduces the recent progress of RPCs based on 2D/3D PCs for visual detection of chemical and biological analytes, including the preparation of 2D PCs, 3D PCs films, 3D PCs microbeads and their applications as visualized sensors. The different cases of detecting various chemical and biological analytes by naked eyes are presented. Emphasis is given to the description of their respective sensing mechanisms with the different systems for chemical and biological analytes. Compared with 3D RPCs sensors, 2D RPCs sensors have shorter response time, better stabilization and higher production efficiency, however, the diffraction intensity of 2D RPCs based on monolayered 2D polystyrene (PS) microsphere array are weak. 2D RPCs sensors based on 2D Au nanosphere can significantly improve the diffraction intensity compared with traditional 2D RPCs sensors based on monolayered PS microsphere array. The much higher scattering cross section of Au nanosphere leads to 2D Au nanosphere array with ultrahigh optical diffraction intensity, which are highly helpful for their practical application as visual sensors and further quantitative detection by monitoring the diffraction peak position and intensity.
TL;DR: In this article, the authors conduct a computational fluid dynamics simulation to investigate the behaviors of bubble breakup in a microfluidic T-junction using volume-of-fluid method to represent the interface.
Abstract: We conduct a computational fluid dynamics simulation to investigate the behaviors of bubble breakup in a microfluidic T-junction using volume-of-fluid method to represent the interface. The evolution of bubble morphology and the distributions of velocity and pressure in flow field are analyzed, and the effect of width ratio between main channel and branch on the bubble morphology are evaluated. The results indicate that, the “tunnel” breakup, obstructed breakup, combined breakup and non-breakup are observed during the bubble flows through the T-junctions under different condition. The whole bubble breakup process undergoes the extension, squeeze and pinch-off stages, while the non-breakup process experiences extension and pushing stages. We find that, in the squeeze stage, a local vortex flow forms at the front edge of the bubble for the “tunnel” breakup while the velocity inside the bubble is of a parabolic distribution for the obstructed breakup. Irrespective of non-breakup regimes, there is a sudden pressure drop occurring at the gas–liquid interface of the bubble in the squeeze stage, and the pressure drop at the front interface is far larger than that at the depression region. The transition of the bubble breakup regime through the T-junction occurs with an increase in width ratio of main channel to the branch, which sequentially experiences the non-breakup regime, “tunnel” breakup regime and obstructed breakup regime. The flow regime diagrams are plotted with a power-law correlation to distinguish the bubble/droplet breakup and non-breakup regimes, which also characterize the difference between bubble and droplet breakup through a T-junction.
TL;DR: This review elaborate recent progress in nanoparticle-based oral formulations, with emphasis on the pathophysiological characteristics of colon site and design strategies to take advantage of these characteristics for colon targeting.
Abstract: Colon-targeted oral delivery is crucial for the treatment of colon-related diseases, as this delivery strategy enables precise drug administration to the diseased site, enhances drug bioavailability, and improves patient compliance. In particular, nanoparticle-based oral formulations shield drugs from the harsh gastrointestinal environment, and selectively increase drug concentration inside diseased colon cells, thus elevating therapeutic efficacy while reducing systemic toxicity. In this review, we elaborate recent progress in this area, with emphasis on the pathophysiological characteristics of colon site and design strategies to take advantage of these characteristics for colon targeting.