Showing papers by "Henan Normal University published in 2014"
TL;DR: The PT-symmetric phonon laser with balanced gain and loss is introduced by introducing gain to one of the microcavities such that it balances the passive loss of the other, resulting in a highly efficient phonon-lasing action.
Abstract: By exploiting recent developments associated with coupled microcavities, we introduce the concept of the PT-symmetric phonon laser with balanced gain and loss. This is accomplished by introducing gain to one of the microcavities such that it balances the passive loss of the other. In the vicinity of the gain-loss balance, a strong nonlinear relation emerges between the intracavity-photon intensity and the input power. This then leads to a giant enhancement of both optical pressure and mechanical gain, resulting in a highly efficient phonon-lasing action. These results provide a promising approach for manipulating optomechanical systems through PT-symmetric concepts. Potential applications range from enhancing mechanical cooling to designing phonon-laser amplifiers.
526 citations
TL;DR: In this paper, a comprehensive overview and description of graphene-based nanomaterials explored in recent years for catalyst supports and metal-free catalysts for polymer electrolyte membrane (PEM) fuel cell oxygen reduction reactions (ORR) is presented.
Abstract: A comprehensive overview and description of graphene-based nanomaterials explored in recent years for catalyst supports and metal-free catalysts for polymer electrolyte membrane (PEM) fuel cell oxygen reduction reactions (ORR) is presented. The catalyst material structures/morphologies, material selection, and design for synthesis, catalytic performance, catalytic mechanisms, and theoretical approaches for catalyst down-selection and catalyzed ORR mechanisms are emphasized with respect to the performance of ORR catalysts in terms of both activity and stability. When graphene-based materials, including graphene and doped graphene, are used as the supporting materials for both Pt/Pt alloy catalysts and non-precious metal catalyst, the resulting ORR catalysts can give superior catalyst activity and stability compared to those of conventional carbon-supported catalysts; when they are used as metal-free ORR catalysts, significant catalytic activity and stability are observed. The nitrogen-doped graphene materials even show superior performance compared to supported metal catalysts. Challenges including the lack of material mass production, unoptimized catalyst structure/morphology, insufficient fundamental understanding, and testing tools/protocols for performance optimization and validation are identified, and approaches to address these challenges are suggested.
420 citations
TL;DR: The role of ILs as catalysts, solvents, or electrolytes in three broadly interesting energy production processes from renewable resources, such as CO2 conversion to fuels and fuel additives, biomass pretreatment and conversion to biofuels, as well as solar energy and energy storage is emphasised.
Abstract: To mitigate the growing pressure on resource depletion and environment degradation, the development of green processes for the production of renewable energy is highly required. As a class of novel and promising media, ionic liquids (ILs) have shown infusive potential applications in energy production. Aiming to offer a critical overview regarding the new challenges and opportunities of ILs for developing green processes of renewable energy, this article emphasises the role of ILs as catalysts, solvents, or electrolytes in three broadly interesting energy production processes from renewable resources, such as CO2 conversion to fuels and fuel additives, biomass pretreatment and conversion to biofuels, as well as solar energy and energy storage. It is expected that this article will stimulate a generation of new ideas and new technologies in IL-based renewable energy production.
363 citations
TL;DR: It is suggested that JA could effectively protect wheat seedlings from salt stress damage by enhancing activities of antioxidant enzymes and the concentration of antioxidative compounds to quench the excessive reactive oxygen species caused by salt stress and presented a practical implication for wheat cultivation in salt-affected soils.
308 citations
TL;DR: In this paper, a study of the process e(+)e(-) -> pi(+/-) (D (D) over bar*)(-/+) at root s = 4.26 GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring.
Abstract: We report on a study of the process e(+)e(-) -> pi(+/-) (D (D) over bar*)(-/+) at root s = 4.26 GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (D (D) over bar*)(-/+) invariant mass distribution. When fitted to a mass- dependent- width Breit- Wigner line shape, the pole mass and width are determined to be M-pole (3883: 9 +/- 1.5 (stat) +/- 4.2 dsyst__ MeV= c(2) and Gamma(pole) = (24: 8 +/- 3.3 (stat) +/- 11: 0 (syst)) MeV. The mass and width of the structure, which we refer to as Z(c)(3885), are 2 sigma and 1 sigma, respectively, below those of the Z(c)(3900) -> pi(+/-) J/psi peak observed by BESIII and Belle in pi(+)pi(-) J/psi final states produced at the same center- of- mass energy. The angular distribution of the pi Z(c)(3885) system favors a J(P) = J(P) = 1(+) quantum number assignment for the structure and disfavors 1(-) or 0(-). The Born cross section times the (D (D) over bar*) branching fraction of the Z(c)(3885) is measured to be sigma(e(+)e(-) -> pi(+/-)Z(c)(3885)(-/+)) x B(Z(c)(3885)-/+ -> (D (D) over bar*)(-/+) = (83.5 +/- 6.6 (stat) +/- 22.0 (syst)) pb. Assuming the Z(c)(3885) -> (D (D) over bar*)(-/+) signal reported here and the Z(c)(3900) -> pi J/psi signal are from the same source, the partial width ratio (Gamma(Z(c)(3885) -> D (D) over bar*)/Gamma(Z(c)(3900) -> pi J/psi)) = 6.2 +/- 1.1 (stat) +/- 2.7 (syst) is determined.
254 citations
TL;DR: In this article, the authors studied the process e(+)e(-) -> (D* (D) over bar*)(+/-)pi(-/+) at a center-of-mass energy of 4.26 GeV using a 827 pb(-1) data sample obtained with the BESIII detector.
Abstract: We study the process e(+)e(-) -> (D* (D) over bar*)(+/-)pi(-/+) at a center-of-mass energy of 4.26 GeV using a 827 pb(-1) data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be (137 +/- 9 +/- 15) pb. We observe a structure near the (D* (D) over bar*)(+/-) threshold in the pi(-/+) recoil mass spectrum, which we denote as the Z(c)(+/-) (4025). The measured mass and width of the structure are (4026.3 +/- 2.6 +/- 3.7) MeV/c(2) and (24.8 +/- 5.6 +/- 7.7) MeV, respectively. Its production ratio sigma(e(+)e(-) -> Z(c)(+/-)(4025)pi(-/+)-> (D* (D) over bar*)(+/-)pi(-/+)/sigma(e(+)e(-) -> (D* (D) over bar*)(+/-)pi(-/+) is determined to be 0.65 +/- 0.09 +/- 0.06. The first uncertainties are statistical and the second are systematic.
246 citations
TL;DR: In-depth studies should be continuously performed to identify the ligand specificity of all TLRs in fish, particularly non-mammalian TLRs, and their signaling pathways.
237 citations
TL;DR: In this article, a facile, green and scalable approach to synthesize porous N-doped carbon spheres characterised by high specific surface areas (2105.9 m2 g−1) and high porosity (1.14 cm3 g− 1), which exhibit not only excellent electrocatalytic activity toward the four electron oxygen reduction reaction with long-term stability for fuel cells, but also have excellent resistance to crossover effects and CO poisoning superior to that of the commercial Pt/C catalyst.
Abstract: The urgent need for sustainable energy development depends on the progress of green technologies, which have steered hot research areas into environmentally benign approaches via inexpensive precursors and abundant resources obtained directly from nature for energy devices such as fuel cells and supercapacitors. By using fermented rice as starting materials, we herein demonstrate a facile, green and scalable approach to synthesize porous N-doped carbon spheres characterised by high specific surface areas (2105.9 m2 g−1) and high porosity (1.14 cm3 g−1), which exhibit not only excellent electrocatalytic activity toward the four-electron oxygen reduction reaction with long-term stability for fuel cells, but also have excellent resistance to crossover effects and CO poisoning superior to that of the commercial Pt/C catalyst. Furthermore, the naturally derived porous N-doped carbon spheres, used as the active electrode materials, present superior performance for capacitors with a capacitance of 219 F g−1 at a high discharge current density of 15 A g−1 and good cycling stability for over 4400 cycles. This work shows a good example for taking advantage of the abundant resources provided by nature, and opening the door for the creation of functional materials with promising applications in high-performance renewable devices related to energy conversion and storage.
197 citations
TL;DR: In this paper, the effect of cationic structures on the cellulose dissolution at a given temperature was investigated, and it was found that acidic protons on the heterocyclic rings of the cations are essential for the dissolution of cellulose in the ILs, but the van der Waals interaction of Cation with cellulose is not important.
188 citations
TL;DR: In this paper, the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.009 to 4.420 GeV is observed for the first time with a statistical significance of 6.3 sigma.
Abstract: With data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.009 to 4.420 GeV, the process e(+)e(-) -> gamma X(3872) is observed for the first time with a statistical significance of 6.3 sigma. The measured mass of the X(3872) is (3871.9 +/- 0.7(stat) +/- 0.2(syst)) MeV/c(2), in agreement with previous measurements. Measurements of the product of the cross section sigma[e(+)e(-) -> gamma X(3872)] and the branching fraction B [X(3872) -> pi(+)pi(-)J/psi] at center-of-mass energies 4.009, 4.229, 4.260, and 4.360 GeV are reported. Our measurements are consistent with expectations for the radiative transition process Y(4260) -> gamma X(3872).
166 citations
TL;DR: In this paper, a simple and cost-effective method for the tailored synthesis of uniform three dimensional (3D) acicular sheaf shaped BiVO4 architectures under mild conditions was designed, where the as-synthesized biVO4 products were then incorporated with prepared reduced graphene oxide (RGO) sheets to form novel Bi VO4/RGO composites.
TL;DR: In this paper, uniform α- and β-Bi 2 O 3 hollow microspheres were successfully synthesized through a facile template-free solvothermal method followed by calcination of the precursor.
TL;DR: The microstructure of ionic liquids (ILs) has attracted much attention due to their relevance in physiochemical properties and behavior of ILs, and the possible formation mechanism of the IL clusters is described.
Abstract: The microstructure of ionic liquids (ILs) has attracted much attention due to their relevance in physiochemical properties and behavior of ILs. The existence of clusters (or microheterogeneous structure) is one of the main features for many ILs, which provides fundamental information for understanding the performance of ILs in their applications. This perspective concentrates on the recent progresses in IL clusters research. Firstly, we give a brief introduction on the structure of clusters in neat ILs and IL solutions. Secondly, the possible formation mechanism of the IL clusters is described. Then, the effects of the clusters on the physicochemical properties, interfacial properties, confined geometry and assembly processes of ILs are discussed. Finally, we address the associated challenges and prospects on the future study of IL clusters.
TL;DR: In this article, a chemically grafted p-aniline-functionalized graphene-polyanilines composite (a-G-PANI) is synthesized by covalent bonding and polymerization of aniline onto p-Aniline functionalized graphene substrate.
TL;DR: It was found that the as-synthesized CZO@C composites enabled a reversible capacity of 725 mA h g (-1) up to the 50th cycle at a current density of 100 mA g(-1), which was higher than that of ZnO@B composites.
Abstract: Cobalt (Co)-doped MOF-5s (Co-MOF-5s) were first synthesized by a secondary growth method, followed by a heat treatment to yield Co-doped ZnO coated with carbon (CZO@C). Compared with carbon-coated ZnO (ZnO@C), the doping of Co increased the graphitization degree of the carbon on the surface of CZO@C nanoparticles and enhanced the conductivity of the material. The electrochemical properties of the materials were characterized by galvanostatic discharge/charge tests. It was found that the as-synthesized CZO@C composites enabled a reversible capacity of 725 mA h g–1 up to the 50th cycle at a current density of 100 mA g–1, which was higher than that of ZnO@C composites (335 mA h g–1).
TL;DR: In this paper, a simple and green approach to prepare water-soluble, nitrogen-, sulfur-, and phosphorus-co-doped carbon dots (N/S/P-CDs) by one step hydrothermal treatment of cucumber juice is reported.
Abstract: A simple and green approach to prepare water-soluble, nitrogen-, sulfur-, and phosphorus-co-doped carbon dots (N/S/P-CDs) by one step hydrothermal treatment of cucumber juice is reported. The resultant N/S/P-CDs possess a uniform morphology, a size of less than 10 nm, plentiful O and N functional groups as well as a limited amount of P and S functional groups, and exhibit good luminescence stability, high resistance to photobleaching, high solubility, and excitation-dependent emission behavior. It was also found that a higher reaction temperature favors the formation of N/S/P-CDs with smaller size and longer wavelength of photoluminescence emissions. Moreover, the N/S/P-CDs can be applied as a fluorescent probe for the detection of Hg2+ ions.
TL;DR: In this paper, a strategy to search for light, nearly degenerate higgsinos within the natural MSSM at the LHC was investigated. And the proposed method can also probe certain region in the parameter space for the lightest neutralino with a high higgsino purity, that cannot be reached by planned direct detection experiments at XENON-1T(2017).
Abstract: We investigate a strategy to search for light, nearly degenerate higgsinos within the natural MSSM at the LHC. We demonstrate that the higgsino mass range mu in 100 - 160 GeV, which is preferred by the naturalness, can be probed at 3 sigma significance through the monojet search at 14TeV HL-LHC with 3000 fb(-1) luminosity. The proposed method can also probe certain region in the parameter space for the lightest neutralino with a high higgsino purity, that cannot be reached by planned direct detection experiments at XENON-1T(2017).
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TL;DR: It is shown that every principal sub-tensor of such a structured Tensor is still a structured tensor in the same class, with a lower dimension, and the potential links of such structured tensors with optimization, nonlinear equations, non linear complementarity problems, variational inequalities and the non-negative tensor theory are discussed.
Abstract: In this paper, we extend some classes of structured matrices to higher order tensors. We discuss their relationships with positive semi-definite tensors and some other structured tensors. We show that every principal sub-tensor of such a structured tensor is still a structured tensor in the same class, with a lower dimension. The potential links of such structured tensors with optimization, nonlinear equations, nonlinear complementarity problems, variational inequalities and the nonnegative tensor theory are also discussed.
TL;DR: In this article, the fabrication of novel ZnSnO3 hollow nanospheres/reduced graphene oxide (RGO) hybrid nanocomposite is reported for the first time.
Abstract: The fabrication of novel ZnSnO3 hollow nanospheres/reduced graphene oxide (RGO) hybrid nanocomposite is reported for the first time. The nanocomposites were synthesized via a facile route, and were well characterized with the aid of XRD, FTIR, SEM, TEM, BET, UV–vis, and PL techniques. Moreover, the synthesized nanocomposites were used as photocatalysts in the application of the degradation of pharmaceutical wastewater. In this study, ZnSnO3 hollow nanospheres showed high efficiency in photocatalytic degradation of metronidazole under ultraviolet (UV) light irradiation. More interestingly, the photocatalytic activities of these nanospheres could be enhanced by coupling with RGO, where a large improvement (approx. 30.4% increase compared with pure ZnSnO3) in photodegradation of metronidazole was observed on the prepared ZnSnO3/RGO hybrid nanocomposites under visible light irradiation. This improvement might be attributed to the advanced adsorption efficiency of molecules and enhanced visible light absorption within the hybrid nanocomposites by the introduction of RGO. Such study might pave the way toward designing novel photocatalyst systems for efficient degradation of pharmaceutical wastewater.
TL;DR: In this article, a green strategy for synthesizing nitrogen-doped carbon dots (N-CDs) via hydrothermal treatment of willow leaves was developed, and the supernatant exhibits strong blue fluorescence under UV radiation and can be directly used as a fluorescent ink.
Abstract: A green strategy has been developed for synthesizing nitrogen-doped carbon dots (N-CDs) via hydrothermal treatment of willow leaves. The supernatant exhibits strong blue fluorescence under UV radiation and can be directly used as a fluorescent ink, while the solid product with pyrolysis possesses excellent electrocatalytic activity for a highly efficient oxygen reduction reaction with great stability and methanol/CO tolerance superior to a commercial Pt/C catalyst.
TL;DR: In this paper, the shape control of bismuth vanadate (BiVO4) hierarchical structures and their corresponding natural sunlight-driven photocatalytic activities was performed.
Abstract: A detailed study on the shape control of bismuth vanadate (BiVO4) hierarchical structures and on their corresponding natural sunlight-driven photocatalytic activities was performed. We have developed a time-saving, cost-effective, surfactant-free approach for the controlled synthesis of uniform monoclinic scheelite BiVO4 hierarchical structures, obtaining diverse BiVO4 architectures including peanuts, dumbbells, flowers, spheres, olives, and rod-sheaves, via facile pH-dictated solvothermal routes with the aid of either NH3·H2O or NaOH. The influences of the morphologies of the synthesized BiVO4 hierarchical structures on the photocatalytic degradation of Rhodamine B (RhB) have been investigated, indicating that the enhanced photocatalytic performances were neither related to the surface area values nor the aspect ratios of the fabricated photocatalysts, but associated with the unique shaped configurations produced under specific low temperature hydrothermal conditions. The effects of the active species involved in the photocatalytic process and the cycle-stability of the prepared BiVO4 photocatalysts have also been examined.
TL;DR: In this paper, the geometry, electronic structure and catalytic properties of Si-doped graphene (Si-graphene) are investigated based on the first-principle methods.
TL;DR: In this article, the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of root s = 4.36 GeV was used to observe e(+)e(-) -> pi(0)pi( 0)h(c) for the first time.
Abstract: Using data collected with the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of root s = 4.23, 4.26, and 4.36 GeV, we observe e(+)e(-) -> pi(0)pi(0)h(c) for the first time. The Born cross sections are measured and found to be about half of those of e(+)e(-) -> pi(+)pi(-)h(c) within less than 2 sigma. In the pi(0)h(c) mass spectrum, a structure at 4.02 GeV/c(2) is found. It is most likely to be the neutral isospin partner of the Z(c)(4020)(+/-) observed in the process of e(+)e(-) -> pi(+)pi(-)h(c) being found. A fit to the pi(0)h(c) invariant mass spectrum, with the width of the Z(c)(4020)(0) fixed to that of its charged isospin partner and possible interferences with non-Z(c)(4020)(0) amplitudes neglected, gives a mass of (4023.9 +/- 2.2 +/- 3.8) MeV/c(2) for the Z(c)(4020)(0), where the first error is statistical and the second systematic.
TL;DR: Results showed that the oxidase-like activity of the Co3O4 NPs was not from •OH or O2•- radical generated, and may probably originate from their ability to transfer an electron between the peroxidase substrate and oxygen absorbed on the surface of theCo3O2 NPs.
Abstract: In this paper, we first discovered that Co3O4 nanoparticles (NPs) possess intrinsic oxidase-like activity and can catalytically oxidize peroxidase substrates, such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 3,3′,5,5′-tetramethylbenzidine (TMB), to form colored products, in the absence of exogenously added H2O2. The presence of sulfite inhibited the TMB–O2–Co3O4 NPs reaction system and caused a change in color of the reaction system. On the basis of this phenomenon, a colormetric approach to detect sulfite was established with a good linear relationship ranging from 0.2 × 10–6 to 1.6 × 10–5 M and a detection limit of 5.3 × 10–8 M. The method was used to detect sulfite in foods. Good recoveries ranging from 93.8% to 100.5% were obtained. Furthermore, the mechanism was studied and results showed that the oxidase-like activity of the Co3O4 NPs was not from •OH or O2•– radical generated. It may probably originate from their ability to transfer an electron between the p...
TL;DR: In this article, a phenyl-containing azole-based ionic liquid with an enhanced π⋯S interaction was used to capture acid gases such as SO2.
TL;DR: This paper shows that a symmetric B tensor can always be decomposed to the sum of a strictly diagonally dominated symmetric M tensor and several positive multiples of partially all one tensors.
TL;DR: Based on density functional theory, the characteristics of n- and p-type impurities are investigated firstly by means of group V and VII atoms substituting sulfur atoms in the SnS2 monolayer nanosheets and show that the formation energy and transition levels depend highly on the atomic size and electronegativity of the impurity atom.
Abstract: Based on density functional theory, the characteristics of n- and p-type impurities are investigated firstly by means of group V and VII atoms substituting sulfur atoms in the SnS2 monolayer nanosheets. Numerical results show that the formation energy and transition levels depend highly on the atomic size and electronegativity of the impurity atom. The formation energies increase with the increasing impurity atom size for each considered doping case. For group V atom-doped SnS2 monolayer nanosheet systems, the calculations of the transition level indicate that N, P or As doping is not effective for p-type conductivity. However, for group VII atom doping cases, F, Cl, Br and I impurities can offer effective n-type carriers in the SnS2 monolayer nanosheets.
TL;DR: Investigation of the distribution and composition of ARBs in chicken manure and fertilized vegetables indicated that the chicken manure dominantly harbored Firmicutes, Bacteroidetes, Synergistetes and Proteobacteria and that Bacteroids was significantly enhanced in farms utilizing antibiotics.
Abstract: Veterinary manure is an important pollution reservoir of antibiotics and antibiotic-resistant bacteria (ARB). However, little is known of the distribution of ARB in plant endophytic bacteria and the number/types of ARB in chicken manure. In this study, 454-pyrosequencing was used to investigate the distribution and composition of ARBs in chicken manure and fertilized vegetables. The prevalence of ARB in the samples of the chicken manure compost recovered from farms on which amoxicillin, kanamycin, gentamicin, and cephalexin were used was 20.91-65.9% for ARBs and 8.24-20.63% simultaneously resistant to two or more antibiotics (multiple antibiotic resistant bacteria (MARB)). Antibiotic-resistant endophytic bacteria were widely detected in celery, pakchoi, and cucumber with the highest rate of resistance to cephalexin. The pyrosequencing indicated that the chicken manure dominantly harbored Firmicutes, Bacteroidetes, Synergistetes, and Proteobacteria and that Bacteroidetes was significantly enhanced in farms utilizing antibiotics. In the total cultivable colonies, 62.58-89.43% ARBs and 95.29% MARB were clustered in Bacteroidetes with the dominant species (Myroides ordoratimimus and Spningobacterium spp., respectively) related to human clinical opportunistic pathogens.
TL;DR: In this article, the stable configuration, electronic structure, magnetic property and catalytic activity of single-atom non-noble-metal (NNM) catalysts on graphene were investigated using the first-principles method.
TL;DR: Ammonia borane (NH3BH3) has yielded its secrets grudgingly since its first attempted synthesis in 1923 as discussed by the authors, and its chemistry and properties have been reviewed in detail.