Showing papers by "Lei Wang published in 2019"

CAS FGOALS-f3-L Model Datasets for CMIP6 Historical Atmospheric Model Intercomparison Project Simulation

Abstract: The outputs of the Chinese Academy of Sciences (CAS) Flexible Global Ocean-Atmosphere-Land System (FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diagnostic, Evaluation and Characterization of Klima common experiments of phase 6 of the Coupled Model Intercomparison Project (CMIP6) are described in this paper. The CAS FGOALS-f3-L model, experiment settings, and outputs are all given. In total, there are three ensemble experiments over the period 1979–2014, which are performed with different initial states. The model outputs contain a total of 37 variables and include the required three-hourly mean, six-hourly transient, daily and monthly mean datasets. The baseline performances of the model are validated at different time scales. The preliminary evaluation suggests that the CAS FGOALS-f3-L model can capture the basic patterns of atmospheric circulation and precipitation well, including the propagation of the Madden-Julian Oscillation, activities of tropical cyclones, and the characterization of extreme precipitation. These datasets contribute to the benchmark of current model behaviors for the desired continuity of CMIP.

Outlook for El Niño and the Indian Ocean Dipole in autumn-winter 2018–2019

Abstract: El Nino-Southern Oscillation (ENSO) in the equatorial Pacific Ocean and the Indian Ocean Dipole (IOD) in the equatorial Indian Ocean are two major natural variabilities on seasonal and inter-annual timescales. In this study, the Flexible Global Ocean-Atmosphere-Land System Model, finite volume version 2 (FGOALS-f2), sub-seasonal to seasonal (S2S) climate prediction system, was used to make a seasonal prediction for autumn and winter 2018–2019. The FGOALS-f2 S2S prediction system was developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), and is run on Chinas Tianhe-2 supercomputer located at the National Supercomputer Center in Guangzhou, China. The model used in the prediction system is CAS FGOALS-f2, which is a next-generation climate system model of LASG-IAP, representing the interaction between the atmosphere, oceans, land, and sea ice. The seasonal prediction products from this system have been submitted to and used operationally by the National Climate Center of the China Meteorological Administration, as well as the National Marine Environmental Forecasting Center of China, since June 2017. The FGOALS-f2 S2S prediction system has achieved 37 a retrospective forecasts (reforecasts) covering the period 1981–2017. The reforecast experiments include 24 ensemble members, while the real-time prediction uses 35 ensemble members. The latest prediction results, in July 2018, reveal that: (1) A positive IOD will persist through autumn and winter 2018–2019, and the peak phase will be in October with an amplitude of approximately 0.4°C. Based on the 37 a reforecasts predicted from each July 20th, the one-month-lead prediction skill of the IOD is 0.82 in the IOD prediction of July, and the five-month-lead prediction skill is 0.56. (2) In the equatorial Pacific Ocean, the prediction results reveal a Moderate El Nino is under development, and Nino3.4 index values may reach approximately 1.3°C. Based on the 37 a reforecasts predicted from each July 20th, the one-month lead prediction skill of the Nino3.4 index is 0.97 in the ENSO prediction of July, and the six-month lead prediction skill is 0.83. (3) The Moderate El Nino and positive IOD may induce a weak China winter monsoon, characterized by a warm winter. For North China, the meteorological conditions are expected to have adverse effects on atmospheric diffusion; while for South China, warm and wet conditions are likely to prevail, since the lower-level jet of the Indian Ocean is predicted to strengthen. To better predict the equatorial sea surface temperature anomalies in the eastern Pacific and Indian oceans, the FGOALS-f2 S2S climate prediction team will continue to update the prediction results on the 20th of every month, releasing them (with respect to ENSO, the IOD, climate, and average monthly weather in China) on the website, and report the latest prediction results via the WeChat public platform.

Spatial distributions and temporal variations of the near-surface soil freeze state across China under climate change

Abstract: The near-surface soil freeze state is affected by global warming, and its changes have profound effects on landscapes, ecosystems and hydrological processes. On the basis of daily soil freeze observational data at 476 meteorological stations over 50 freezing years from September 1, 1961 to August 31, 2011, the spatial distributions and temporal variations of the near-surface soil freeze state were estimated using five freeze variables (first date, last date, maximum seasonally frozen depth, duration and actual number of freeze days) across China, which was divided into three regions (eastern China, northwestern China and the Qinghai-Tibetan Plateau (QTP)). The near-surface soil freeze state varied greatly across China. The QTP has an earlier freeze, later thaw, longer freeze days and deeper seasonally frozen depth than the other two regions. The spatial distributions of the near-surface soil freeze state can be explained largely by altitude in northwestern China and on the QTP, whereas they can be explained by latitude in eastern China. The near-surface soil freeze state has changed significantly over 50 freezing years. On average across China over the study period, the first date of freezing was delayed by approximately 10 ± 1 days with a rate of 0.20 ± 0.02 days/year, the last date advanced by approximately 18 ± 2 days with a rate of 0.36 ± 0.04 days/year, the duration and the number of freeze days decreased by 28 ± 2 and 23 ± 2 days with rates of 0.56 ± 0.04 and 0.45 ± 0.04 days/year, respectively, and the maximum seasonally frozen depth decreased by 20 ± 3 cm with a rate of 0.41 ± 0.06 cm/year. The change in the freeze variables is relatively large in high-latitude and high-altitude regions.

Biodiversity of the microbiota in Spodoptera exigua (Lepidoptera: Noctuidae).

Abstract: Aims Spodoptera exigua is a serious pest of many agricultural crops. However, the bacterial communities of S. exigua are poorly studied, particularly over their entire life cycle. We aimed to study the biodiversity of the microbiota across the life cycle of S. exigua and to provide a better and obtain insight into new pest control strategies. Methods and results The bacterial diversity across the life cycle of S. exigua was studied using Illumina MiSeq sequencing of 16S rRNA genes. Spodoptera exigua is dominated by Proteobacteria and Firmicutes, with a total relative abundance of 90·03%. Enterococcus (24·6%), Pseudomonas (12·2%) and Asaia (45·9%) were abundant and active in eggs, while Methylobacterium (18·7%) and Halomonas (16·5%) dominated freshly eclosed larvae. The 3rd and 5th instar larvae were dominated by Enterococcus (76·3 and 62·0%). Pupal stages had the highest microbial diversity. There was no significant difference between newly emerged males and females. Symbionts of eggs were extremely similar and probably vertically transmitted by males during mating. Conclusions The result showed that the bacterial community was affected by the host developmental stages. Our results also suggest that symbionts of egg mass are probably vertically transmitted control by male spawning adults. Significance and impact of the study Our study documents the symbiont bacteria across the life cycle of S. exigua. Understanding the microbial symbionts may provide clues to develop potential biocontrol techniques against this pest.

Change characteristics of precipitation and temperature in the Qilian Mountains and Hexi Oasis, Northwestern China

Abstract: Precipitation and temperature in the Qilian Mountains and the Hexi oasis are changing with climate change. The characteristics and control factors of these changes are not well understood, affecting the ability to allocate water resources in this area judiciously. We analyzed the annual and seasonal variability in precipitation and temperature during 1960–2016 using monthly data from 25 national meteorological stations in the Qilian Mountains. Results showed that precipitation increased by 6.2, 4.1, and 8.9 mm/decade for the whole regions (including oasis and mountains), oasis, and mountains, respectively. Variability in summer precipitation made the greatest contribution to the annual change in precipitation. Moreover, the increment in precipitation was amplified with elevation. Enhanced westerly circulation and increased water vapor were the factors responsible for the increased precipitation in the study area. Temperature in the whole regions, oasis, and mountains increased at the rate of 0.32, 0.32, and 0.33 °C/decade, respectively. Changes in temperature were greatest in winter, with 0.47, 0.36 and 0.50 °C/decade in the whole regions, oasis, and mountains, respectively; changes in winter temperature made the greatest contribution to the annual temperature changes. Seasonal differences in carbon dioxide concentration may have caused the seasonal differences in the rate of temperature increase. The annual increase in temperature was mainly due to Siberian High, and Arctic Oscillation, carbon emissions and decreased cloud cover in the study area. The study results will help evaluate climatic hazards and contribute to development of water resources management strategies such as supplementary irrigation.

An Improved Spatial–Temporal Downscaling Method for TRMM Precipitation Datasets in Alpine Regions: A Case Study in Northwestern China’s Qilian Mountains

Abstract: Remote sensing techniques provide data on the spatial–temporal distribution of environmental parameters over regions with sparse ground observations. However, the resolution of satellite precipitation data is too coarse to be applied to hydrological and meteorological research at basin scales. Downscaling research using coarse remote sensing data to obtain high-resolution precipitation data is significant for the development of basin-scale research. Here, we propose improvements to a spatial–temporal method for downscaling satellite precipitation. The improved method uses a nonlinear regression model and introduces longitude and latitude based on processed normalized difference vegetation index (NDVI) and a digital elevation model (DEM) to stimulate precipitation in the Qilian Mountains during 2006–2015. The final downscaled annual precipitation (FDAP) results are corrected by observed data to obtain corrected final downscaled annual precipitation (CFDAP) datasets. For temporal downscaling, monthly downscaled data are the corrected monthly ratio multiplied by the corresponding downscaled annual datasets. The results indicated that processed NDVI (PNDVI) reflected spatial precipitation patterns more accurately than the original NDVI. The accuracy was significantly improved when the final downscaled annual precipitation data were corrected by observed data. The average annual root mean square error (RMSE) from 2006 to 2015 of CFDAP was 66.48 and 83.07 mm less than that of FDAP and original Tropical Rainfall Measuring Mission (TRMM) data, respectively. Compared with previous methods, which use NDVI and/or DEM to downscale TRMM, the accuracy of FDAP and CFDAP from the improved method was higher, and the RMSE decreased on average by 13.63 and 80.11 mm. The RMSE of monthly data from corrected monthly ratio (CMR) decreased on average by 4.93 mm over monthly data from previous monthly ratio (PMR). In addition, the accuracy of the original satellite data affected the initial downscaling results but had no significant effects on the corrected downscaling results.

A Balancing Method of Mixed-model Disassembly Line in Random Working Environment

Abstract: Disassembly is a necessary link in reverse supply chain and plays a significant role in green manufacturing and sustainable development. However, the mixed-model disassembly of multiple types of retired mechanical products is hard to be implemented by random influence factors such as service time of retired products, degree of wear and tear, proficiency level of workers and structural differences between products in the actual production process. Therefore, this paper presented a balancing method of mixed-model disassembly line in a random working environment. The random influence of structure similarity of multiple products on the disassembly line balance was considered and the workstation number, load balancing index, prior disassembly of high demand parts and cost minimization of invalid operations were taken as targets for the balancing model establishment of the mixed-model disassembly line. An improved algorithm, adaptive simulated annealing genetic algorithm (ASAGA), was adopted to solve the balancing model and the local and global optimization ability were enhanced obviously. Finally, we took the mixed-model disassembly of multi-engine products as an example and verified the practicability and effectiveness of the proposed model and algorithm through comparison with genetic algorithm (GA) and simulated annealing algorithm (SA).

Controllable dispersion and reunion of liquid metal droplets

Abstract: Liquid metal (LM) micro-droplets have been widely used in microfluidics, drug-loaded nano-system and micro-nano machine due to its excellent properties. However, there still exist difficulties in succinctly dispersing a bulk of LM into micro-droplets due to the large interfacial tension. Besides, the controllable switching between droplet dispersion and reunion is yet to be realized. Herein, a practical and efficient method for dispersing LM was proposed and the controllable switching between dispersion and reunion of LM droplets was achieved. LM micro-droplets were produced by vibrating the LM immersed in a mixture of N , N -dimethylformamide (DMF) and polyvinyl chloride (PVC). The experimental results show that the size distribution of LM micro-droplets could be tuned by controlling the vibration frequency. More intriguingly, the dispersion and reunion of LM droplets can be switched intelligently through tuning the vibration frequency and amplitude. Furthermore, optical properties of the LM micro-droplet coating were evaluated to display potential applications. A self-driven motion of PVC-coated LM could be achieved by utilizing the produced LM micro-droplets based on the Marangoni effect, which holds promising value for developing future transport tool of LM droplets. The present work suggests an entirely feasible method for dispersing and utilizing LM droplets, which is of great significance for promoting the development of LM micro-droplet science and technology.

Response of low flows under climate warming in high‐altitude permafrost regions in western China

Abstract: The increase in low flows (winter discharge and minimum monthly discharge), caused primarily by permafrost degradation, is common in high‐latitude permafrost regions, whereas the dynamics of low flows in high‐altitude permafrost regions remain largely unknown. Long‐term discharge data from 28 unregulated catchments in western China were analysed, and the findings showed that winter discharge/minimum monthly discharge significantly increased (p ≤ 0.1) in 82/82%, 55/64%, and 0/0% of the catchments in the higher‐latitude mountain permafrost regions (Tienshan Mountains), mid‐latitude mountain permafrost regions (Qilian Mountains), and mid‐ to low‐latitude plateau permafrost regions (the source regions of the Yangtze and Yellow rivers), respectively. The differences in permafrost type and the distribution of permafrost and alpine cold desert (which is similar to tundra) were found to be the main causes for the different responses in the low flows. The rate of change of low flows (winter discharge and minimum monthly discharge) was negatively and linearly correlated with permafrost coverage when coverage was less than 40% of the catchment area, whereas the low flows changed only slightly when the permafrost coverage exceeded 40%. A significant thickening of the active layer increased the low flows in the lower permafrost‐covered catchments, which are dominated by warm permafrost. However, in the higher permafrost‐covered catchments with cold permafrost and a cold climate, only an increase in permafrost temperature (without a notable thickening of the active layer) occurred, resulting in non‐significant changes in low flows.

A facile approach to synthesize in situ functionalized graphene oxide/epoxy resin nanocomposites: mechanical and thermal properties

Abstract: The complex preparation processes of GO/polymer composites are a limitation for their application. In this study, epoxy composites filled with in situ functionalized graphene oxide (GO) were prepared by a facile wet mixing and solvent evaporation method. The structure and composition of 3′,4′-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (2021P)-functionalized GO (GO-2021P) were characterized. With surface modification, GO became more thermally stable and changed its nature from hydrophilic to hydrophobic. The influences of surface functionalization on the morphology of GO, its dispersion in the epoxy matrix, the mechanical and thermal behavior of the composites were fully investigated. With grafting of 2021P, the dispersion/exfoliation status of GO and interfacial interaction between GO and epoxy matrix were much improved. For epoxy composite with 1.0 wt% GO-2021P, the tensile strength and Young’s modulus increased by 34.0% and 25.9%, respectively. Increased glass transition temperature and thermal stability were also observed by dynamic mechanical analysis and thermogravimetric analysis. High-performance functionalized GO/epoxy composites can be produced using this technique.

Mesenchymal Sufu Regulates Development of Mandibular Molars via Shh Signaling

Abstract: Sonic hedgehog (Shh) in dental epithelium regulates tooth morphogenesis by epithelial-mesenchymal signaling transduction. However, the action of Shh signaling regulation in this process is not well understood. Here we find that mesenchymal Suppressor of Fused (Sufu), a major negative regulator of Shh signaling, plays an important role in modulating the tooth germ morphogenesis during the bud-to-cap stage transition. Deletion of Sufu in dental mesenchyme by Dermo1-Cre mice leads to delayed development of mandibular molar into cap stage with defect of primary enamel knot (EK) formation. We show the disruption of cell proliferation and programmed cell death in dental epithelium and mesenchyme in Sufu mutants. Epithelial-specific adhesion molecule E-cadherin is evidently reduced in the bilateral basal cells of tooth germ at E14.5. The cells in the presumptive EK, predominantly expressing P-cadherin, appear stratified but fail to condense. Moreover, the transcripts of primary EK marker genes, including Shh, Fgf4, and p21, are significantly decreased compared to controls. In contrast, we find that deficiency of Sufu results in elevation of Shh signaling in mesenchyme, indicated by the significant upregulation of Gli1 and Ptch1. Meanwhile, the expression of Bmp4 and Fgf3, the critical factors of mesenchymal-epithelial induction, is significantly inhibited in dental mesenchyme. Furthermore, the expression of Runx2 experiences a transient decrease at the bud stage. Taken together, these data suggest that mesenchymal Sufu is necessary for tuning the Shh signaling, which may act as an upstream modulator of Bmp4 and Fgf3 to coordinate the interplay between the dental mesenchyme and epithelium of tooth germ.

A Novel Multi-Efficiency Optimization Method for Disassembly Line Balancing Problem

Abstract: Disassembly is an indispensable part in remanufacturing process. Disassembly line balancing and disassembly mode have direct effects on the disassembly efficiency and resource utilization. Recent researches about disassembly line balancing problem (DLBP) either considered the highest productivity, lowest disassembly cost or some other performance measures. No one has considered these metrics comprehensively. In practical production, ignoring the ratio of resource input and value output within remanufacturing oriented disassembly can result in inefficient or pointless remanufacturing operations. To address the problem, a novel multi-efficiency DLBP optimization method is proposed. Different from the conventional DLBP, destructive disassembly mode is considered not only on un-detachable parts, but also on detachable parts with low value, high energy consumption, and long task time. The time efficiency, energy efficiency, and value efficiency are newly defined as the ultimate optimization objectives. For the characteristics of the multi-objective optimization model, a dual-population discrete artificial bee colony algorithm is proposed. The proposed model and algorithm are validated by different scales examples and applied to an automotive engine disassembly line. The results show that the proposed model is more efficient, and the algorithm is well suited to the multi-objective optimization model.

Effect of Water Stress on Photosynthesis, Chlorophyll Fluorescence Parameters and Water Use Efficiency of Common Reed in the Hexi Corridor

Abstract: Water stress is the major environmental stress that affect agricultural production worldwide, especially in arid and semi-arid regions. This research investigated the effect of water stress on common reed (Phragmites australis (Cav.) Trin. ex Steud.) grown in the West Lake Wetland of Zhangye City, China. We designed with four water treatments (100, 95, 85 and 75% of water field capacity, i.e. CK (100%), mild (95%), moderate (85%) and severe (75%) water deficit regimes). The effect of water stress on photosynthesis and chlorophyll fluorescence parameters was investigated. There was a midday depression in net photosynthetic rate (Pn) for CK, mild and moderate drought, but not for severe drought. Stomatal limitation was dominant for mild treatment. But under severe drought stomatal limitation to photosynthesis was dominating in the morning and nonstomatal limitation was dominating in the afternoon. Compared with CK treatment, Pn, stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (E) and water use efficiency (WUE) were always lower at drought stress. This result suggests that water stress caused the photosynthesis of common reed to be completely blocked and the common reed was a drought-sensitive plant. We found 75% is the moisture threshold for common reed. The decrease in Fm, Fv, Fv/Fm and increase F0 suggested that Rubisco activity reduced and PSII partially inactivated during the day under drought. However, part of this inactivation of PSII might be alleviated under mild or moderate drought, but severe drought cannot. Drought stress also affected the photosynthesis Pn-PAR response curve. Drought stress increased LCP, RD and decreased LSP, Pmax and AQY. This indicates that when common reed suffers from drought, the utilization range of light intensity become narrowed and photosynthetic ability or adaptability to light reduced.

Potential Distribution Shifts of Plant Species under Climate Change in Changbai Mountains, China

Abstract: Shifts in alpine tundra plant species have important consequences for biodiversity and ecosystem services. However, recent research on upward species shifts have focused mainly on polar and high-latitude regions and it therefore remains unclear whether such vegetation change trends also are applicable to the alpine tundra at the southern edges of alpine tundra species distribution. This study evaluated an alpine tundra region within the Changbai Mountains, China, that is part of the southernmost alpine tundra in eastern Eurasia. We investigated plant species shifts in alpine tundra within the Changbai Mountains over the last three decades (1984–2015) by comparing contemporary survey results with historical ones and evaluated potential changes in the distribution of dwarf shrub and herbaceous species over the next three decades (2016–2045) using a combination of observations and simulations. The results of this study revealed that the encroachment of herbaceous plants had altered tundra vegetation to a significant extent over the last three decades, especially within low and middle alpine tundra regions in Changbai Mountains, China. The herbaceous species would continue shifting upward and expanding while their dwarf shrub counterparts would continue shifting upward and shrinking over the next three decades under the RCP 4.5 and RCP 8.5 scenarios. The upward shifts of plant species would not keep up with the rate of climate warming under the RCP 8.5 scenarios. The dominant plant tundra species may transform from dwarf shrubs to herbaceous varieties. The results of this study provide a scientific basis for biodiversity protection under climate change and a reference data set for additional research on alpine vegetation dynamics.

Effects of rising atmospheric CO 2 , climate change, and nitrogen deposition on aboveground net primary production in a temperate forest

Abstract: Temperate forests regrowing fromhistorical land use and land cover change in the easternUS serve as carbon (C) sinks. Environmental drivers have been significantly altered (e.g. rising atmospheric CO2 concentration, warmer temperature, and elevated nitrogen (N) deposition) andwill have awide range of impacts on future forest C sinks. However, the interactions among these environmental drivers are unclear and their effects are subject to uncertainty.We assessed the combined and interactive effects of rising CO2 concentration, climate change (temperature, precipitation), andNdeposition on forest aboveground net primary production (ANPP) and their relative contribution toANPP changes of a temperate forest in the easternUS.Weused a process-based ecosystemmodel PnET-day to simulate coupled cycles of C, water, andNof forest ecosystems.We found that (1) climate change exerted negative effects onANPP (−0.250 kg Cm yr)whereas rising CO2 andNdeposition enhanced ANPP (+0.253,+0.014 kg Cm yr); (2) climate change interactedwith risingCO2 andN deposition to decrease ANPP (−0.032,−0.018 kg Cm yr); rising CO2 andNdeposition acted in synergy to increase ANPP (+0.014 kg Cm yr); (3) changes in ANPPweremainly attributed to rising CO2 and climate changewhereasNdeposition effects and any twoor three-factor interactive effects were relatively small. Our results suggest that the total negative effect sizes will not be offset by the total positive effect sizes, thus resulting in reductions in forest ANPPover the 21st century.

Contribution of the Kodama and 4S pathways to the dibenzothiophene biodegradation in different coastal wetlands under different C/N ratios.

Abstract: Dibenzothiophene (DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation efficiencies were clearly improved with increasing C/N ratio in reed wetland sediments, tidal wetlands sediments and estuary wetland sediments. The quantitative response relationships between DBT degradation rates and related functional genes demonstrate that the Kodama pathway-related gene groups were dominant factors at low C/N ratios, while the 4S-related gene groups mainly determined the degradation rate when the C/N ratio was up to 5. Network analysis also shows that the pathway shifts from the Kodama pathway to the 4S pathway occurred through changes in the connections between functional genomes and rates. Furthermore, there were competition and collaboration between the Kodama and 4S pathways. The 4S pathway-related bacteria were more active in estuary wetland sediments compared with reed wetland sediments and tidal wetland sediments. The higher degradation efficiency in estuary wetland sediments may indicate the greater participation of the 4S pathway in the DBT biodegradation reaction. And the effects of ring cleavage of Kodama pathway caused more complete metabolizing of DBT.

Differences of atmospheric boundary layer characteristics between pre-monsoon and monsoon period over the Erhai Lake

Abstract: The differences in planetary boundary layer characteristics, in particular atmospheric boundary layer height (ABLH), humidity, and local circulations in pre-monsoon and monsoon period over the Erhai Lake, were simulated by the lake-atmosphere coupled model WRF v3.7.1. No lake simulations were also conducted to investigate lake effects over complex topography. During pre-monsoon period, local circulation was fully developed under weak synoptic system. The ABLH ran up to 2300 m or so. During monsoon period, temperature difference between land and lake became smaller, resulting in weaker local circulations. The height of circulation reduced by 500 m, and ABLH ran up to 1100 m during the day. Enhanced soil moisture and low surface temperature due to monsoon rainfalls in July could be the main reason for the slightly lower ABLH over the Erhai Lake area. Specific humidity of the boundary layer increased 8.8 g kg−1 or so during monsoon period. The Erhai Lake enlarged thermal contrast between valley and mountain slope in the Dali Basin. The lake reduced air temperature by 2~3 °C during daytime and increased air temperature by nearly 2 °C in the evening. Due to its small roughness length and large thermal capacity, the Erhai Lake enlarged lake-land temperature difference and local wind speed. A cyclonic circulation was maintained by the combination of mountain breeze and land breeze in the south of the lake. The lake decreased air temperature, increased specific humidity, and reduced ABLH during daytime, whereas the opposite effect is presented at night.

“On Water” Direct Catalytic Vinylogous Aldol Reaction of Silyl Glyoxylates

Abstract: The unique reactivity of water in the direct catalytic vinylogous aldol reaction of silyl glyoxylates is reported. With the hydrogen-bonding networks from water, the unfavorable homogeneous reactio...

Epigenome-wide meta-analysis of PTSD across 10 military and civilian cohorts identifies novel methylation loci

Abstract: Differences in susceptibility to posttraumatic stress disorder (PTSD) may be related to epigenetic differences between PTSD cases and trauma-exposed controls. Such epigenetic differences may provide insight into the biological processes underlying the disorder. Here we describe the results of the largest DNA methylation meta-analysis of PTSD to date with data from the Psychiatric Genomics Consortium (PGC) PTSD Epigenetics Workgroup. Ten cohorts, military and civilian, contributed blood-derived DNA methylation data (HumanMethylation450 BeadChip) from 1,896 PTSD cases (42%) and trauma-exposed controls (58%). Utilizing a common QC and analysis strategy, we identified ten CpG sites associated with PTSD (9.61E-07

Effects of snow-depth change on spring runoff in cryosphere areas of China

Abstract: Based on snow-depth and measured runoff data in the 19 river basins of the cryosphere areas of China, changes in cold season snow depth (CSSD) and spring runoff, and the relationship between CSSD a...

A metabolite of endophytic fungus Cadophora orchidicola from Kalimeris indica serves as a potential fungicide and TLR4 agonist.

Abstract: Aim To investigate the bioactive metabolite of endophytic fungus from Kalimeris indica. Methods and results A strain ZJLQ336 was separated from the leaves of K. indica. It was identified as Cadophora orchidicola based on the phylogenetic analysis of ITS-rDNA sequences. From the fermentation broth a metabolite cercosporamide (compound 1) was isolated, and its structure was determined by spectroscopic analysis. Additionally, this compound was subjected to bioactivity assays, including antifungal activity against seven plant pathogenic fungi, as well as its potential immunoregulatory effects on HEK-BLUE™-hTLR4 cells, splenocytes and macrophages. The results showed that cercosporamide had strong growth inhibition against five common plant pathogenic fungi, including Pestalotia diospyri, Botrytis cinerea, Fusarium oxysporum, Sclerotium rolfsii and Penicillum digitatum with EC50 values of 5·29 × 10-3 , 0·61, 0·93, 2·89 and 6·7 μg ml-1 respectively. Among which S. rolfsii was one of the main pathogens in K. indica. Moreover, cercosporamide not only significantly stimulated TLR4 activation, splenocyte proliferation and production of cytokines, IFN-γ and TNF-α, but also up-regulated the production of TNF-α and NO in RAW264.7 macrophages clearly. Conclusions This is the first report of endophytic C. orchidicola from K. indica and its metabolite cercosporamide. The results of pharmacological tests highlight the potential fungicide and TLR4 agonist of cercosporamide. Significance and impact of the study This study indicates endophytic fungi are good resources for natural bioactive metabolites. It also suggests that cercosporamide is a potential fungicide and TLR4 agonist.

Efficient production of 5-hydroxymethylfurfural from fructose over CuAPO-5 molecular sieves synthesized using an ionothermal method

Abstract: A group of CuAPO-5 molecular sieves with trace Cu were successfully synthesized via an ionothermal method and used for fructose dehydration to 5-hydroxymethylfurfural (HMF) in [BMIM]Br ionic liquid. The 0.06-CuAPO-5 sample displayed excellent performance and a HMF yield of 93.8% was obtained, which could be ascribed to the balance between acid strength and mass transfer efficiency. This work demonstrates that the ionothermal synthesized CuAPO-5 molecular sieve was also a good candidate for the efficient production of HMF.

A τ−1 measurement across three orders of magnitude based on an atomic spin precession magnetometer in self-sustaining mode

Abstract: The absolute measurement of magnetic fields can be realized by monitoring the Larmor precession of atomic spins. Yet, this spin-precession magnetometer can only be put into use in weak magnetic fields and the sensitivity is limited by the coherence time beyond which, the uncertainty decreases as τ−1/2 rate. Now we demonstrate that the dynamic range of an atomic spin magnetometer can be extended to geomagnetic field magnitude with τ−1 property maintained based on the the self-sustaining method. A mean sensitivity of 20 pT/Hz and a frequency response bandwidth of 5 kHz are realized in a magnetic field of 10000 nT. More important applications in large magnetic fields can be enabled in virtue of the superiority using this self-sustaining magnetometer.The absolute measurement of magnetic fields can be realized by monitoring the Larmor precession of atomic spins. Yet, this spin-precession magnetometer can only be put into use in weak magnetic fields and the sensitivity is limited by the coherence time beyond which, the uncertainty decreases as τ−1/2 rate. Now we demonstrate that the dynamic range of an atomic spin magnetometer can be extended to geomagnetic field magnitude with τ−1 property maintained based on the the self-sustaining method. A mean sensitivity of 20 pT/Hz and a frequency response bandwidth of 5 kHz are realized in a magnetic field of 10000 nT. More important applications in large magnetic fields can be enabled in virtue of the superiority using this self-sustaining magnetometer.

Preparation method and application of multistage hierarchical structure iron-nickel alloy catalyst

Abstract: The invention provides a preparation method and application of a multistage hierarchical structure iron-nickel alloy catalyst. According to the invention, a proper amount of citric acid is used as a chelating agent, an excessive metal salt solution is cooperatively utilized, and the high-dispersion monolithic FeNi alloy catalyst with a foamed nickel loading size of 5-12 nm is prepared through a hydrothermal process and subsequent calcination-reduction steps. The bottom layer of the catalyst is composed of nanosheet arrays growing in a staggered manner, and the top layer of the catalyst is spherical nanoparticles formed by self-assembly, so the catalyst is endowed with a developed pore structure, which is favorable for enhancing a subsequent surface catalytic reaction, the resistivity of afoamed nickel substrate is improved, and the catalyst can be used for an electrothermal catalytic process. The multistage hierarchical structure morphology of the catalyst overcomes the defects that atraditional supported catalyst is easy to fall off from the surface of a carrier and has poor dispersity and that active particles are easy to agglomerate, and widens the application range of a foamed nickel material in the field of electrothermal catalysis.