Evaluating the effects of topographical factors on the precipitation simulated by kilometer-scale versus quarter-degree dynamical downscaling models in eastern China

与传统的1/4度(≈25-30 km)动力降尺度模拟相比,公里尺度模拟的降水空间分布与观测结果更为接近.为了研究这一差异原因,本研究以华东地区为例,探究了地形因子在观测和模拟的降水中的作用.为了更好地体现地形因子对降水分布非均匀性的影响,以及不同地形因子作用的尺度差异,本研究采用多尺度地理加权回归模型,对五个主要地形因子与公里尺度和1/4度分辨率模拟的降水的关系进行了评估.基于观测数据的研究结果显示地形起伏度,地形高程和离海岸线距离对华东地区降水分布的非均匀性都有重要影响,其中地形起伏度在研究区大部分站点降水分布中起主导作用;公里尺度模拟结果基本反映了地形起伏度的主导作用;而1/4度模拟结果表现出降水对地形高程的过度依赖.本研究揭示了公里尺度地形分布对中国东部降水的非均匀分布的关键作用,研究结果可以为改进降水模拟提供新的思路.

Soil water repellency and influencing factors of Nitraria tangutorun nebkhas at different succession stages

Abstract： Soil water repellency （WR） is an important physical characteristic of soil surface. It is capable of largely influencing the hydrological and geomorphological processes of soil, as well as affecting the ecological processes of plants, such as growth and seed germination, and has thus been a hot topic in recent research around the world. In this paper, the capillary rise method was used to study the soil WR characteristics of Nitraria tangutorun nebkhas. Soil water repellencies at different succession stages of Nitraria tangutorun were investigated, and the relationships between soil WR and soil organic matter, total N, and total P, soil texture, pH, and concentrations of CO32, HCO3-, CI, SO42-, Na~, K~, Ca2~ and Mg2＋ were discussed. Soil WR may be demonstrated at the following nebkhas dune evolvement stages： extremely degraded〉degraded〉stabilized〉well developed〉newly developed〉quick sand. Apart from some soil at the bottom, the WR of other soils （crest and slope of dune） was found to be largest at the topsoil, and decreased as the soil depth increased. The results showed that multiple factors affected soil WR characteristics e.g. WR increased significantly as the contents of soil organic matter and total N increased, but did not change as the total P content increased. Soil texture was a key factor affecting soil WR; soil WR increased significantly as clay content increased, and decreased significantly as sand content increased. Low pH was shown to be more suitable for the occurrence of soil WR. Four cations （Ca2＋, Mg2＋, K＋ and Na＋） and two anions （CI and SO42） enhanced soil WR, while CO32-decreased it. HCO3- did not show any observable effect. Finally, we established a best-fit general linear model （GLM） between soil-air-water contact angle （CA） and influencing factors （CA=5.606 sand＋6.496 （clay and silt）-2.353 pH＋470.089 CQ2＋11.346 Na＋-407.707 Cl--14.245 SO42-＋0.734 total N-519.521 ）. It was concluded that all soils contain subcritical WR （0°〈CA〈90°）. The development and succession of Nitraria tangutorun nebkhas may improve the formation of soil subcritical WR. There exist significant relationships between soils subcritical WR and soil physical or chemical properties.

Research-training needs of clinical nurses: A nationwide study among tertiary hospitals in China

Objective: This study aimed to evaluate Chinese tertiary hospital nurses' research output,research ability,and their related training needs regarding scientific research methodology and analyze the relations among them.Methods: A nationwide survey was conducted in China on a large sample of tertiary hospital nurses (n =27,335) recruited from 22 provinces,autonomous regions,and municipalities.A validated,self-designed questionnaire,consisted of a common questionnaire,the Science Research Skills Self-Rating Questionnaire (SRSQ) and the Scientific Research Training Needs Questionnaire (SRTNQ) were used to assess nurses' research output,self-rated research skills and research-training needs.Results: The nurses' scientific research participation rates (with 4.13%,7.85%,5.35%,and 2.04% in research projects,research attendance,papers published,and patent,respectively) and their self-rated research skills 25.00 (12.50,37.50) were very low.However,the research training needs were relatively high 53.12(37.50,75.00).Significant differences in research participation rates (research projects,research attendance,papers published,and patent),scientific research skills,and research-training needs were determined by age,highest education level,nursing experience,employment,technical title,administrative post,and clinical tutoring experience (P< 0.05).Female and male nurses had different research participation rates (only research projects and studies published) and scientific research skills (P < 0.05).Positive correlations were observed among research output,scientific research skills,and researchtraining needs (P < 0.01).Conclusions: Nurses' scientific research participation and self-rated research ability were below the optimal despite that they had relatively high research-training needs.Nurses should be provided further research training with tailored content to their characteristics and capacity.

Impacts of Topographic Complexity on Modeling Moisture Transport and Precipitation over the Tibetan Plateau in Summer

The non-hydrostatic global variable resolution model(MPAS-atmosphere)is used to conduct the simulations for the South Asian Summer monsoon season(June,July,and August)in 2015 with a refinement over the Tibetan Plateau(TP)at the convection-permitting scale(4 km).Two experiments with different topographical datasets,complex(4-km)and smooth(60-km)topography,are designed to investigate the impacts of topographical complexity on moisture transport and precipitation.Compared with the observations and reanalysis data,the simulation can successfully capture the general features of key meteorological fields over the TP despite slightly underestimating the inflow through the southern TP.The results indicate that the complex topography can decrease the inward and outward moisture transport,ultimately increasing the total net moisture transport into the TP by~11%.The impacts of complex topography on precipitation are negligible over the TP,but the spatial distributions of precipitation over the Himalayas are significantly modulated.With the inclusion of complex topography,the sharper southern slopes of the Himalayas shift the lifted airflow and hence precipitation northward compared to the smooth topography.In addition,more small-scale valleys are resolved by the inclusion of complex topography,which serve as channels for moisture transport across the Himalayas,further favoring a northward shift of precipitation.Overall,the difference between the two experiments with different topography datasets is mainly attributed to their differing representation of the degree of the southern slopes of the Himalayas and the extent to which the valleys are resolved.

Contrasting vegetation changes in dry and humid regions ofthe Tibetan Plateau over recent decades

An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and associated drivers remain to be explored. This study used a satellite Leaf Area Index(LAI) dataset(the GLASS LAI dataset) and examined vegetation changes in humid and arid regions of the TP during 1982–2012. Based on distributions of the major vegetation types, the TP was divided roughly into a humid southeastern region dominated by meadow and a dry northwestern region covered mainly by steppe. It was found that the dividing line between the two regions corresponded well with the lines of mean annual precipitation of 400 mm and the mean LAI of 0.3. LAI=0.3 was subsequently used as a threshold for investigating vegetation type changes at the interanual and decadal time scales: if LAI increased from less than 0.3 to greater than0.3 from one time period to the next, it was regarded as a change from steppe to meadow, and vice versa. The analysis shows that changes in vegetation types occurred primarily around the dividing line of the two regions, with clear growth(reduction) of the area covered by meadow(steppe), in consistency with the findings from using another independent satellite product. Surface air temperature and precipitation(diurnal temperature range) appeared to contribute positively(negatively) to this change though climate variables displayed varying correlation with LAI for different time periods and different regions.

Seasonal variation in soil microbial biomass carbon and nitrogen in an artificial sand-binding vegetation area in Shapotou, northern China

In this study, seasonal variation characteristics of surface soil microbial biomass carbon （MBC） and soil microbial biomass nitrogen （MBN） of an artificial vegetation area located in Shapotou for different time periods were studied using the chloroform fumigation method, and the results were compared with those of near-natural vegetation areas and mobile dunes. Results showed that the MBC and MBN levels in the 0-5 cm soil layer were higher in autumn than in summer and spring. As the prolongation of vegetation restoration raised the MBC and MBN levels in summer and autumn, no clear variation was found in spring. However, the MBC and MBN in 5-20 cm had no obvious seasonal variation. During summer and autumn, the variation trend of MBC and MBN in the vertical direction was shown to be 0-5 〉 5-10 〉 10-20 cm in the vegetation area, while for mobile dunes, the MBC and MBN levels increased as the depth increased. The natural vegetation area was shown to possess the highest MBC and MBN levels, and yet mobile dunes have the lowest MBC and MBN levels. MBC and MBN levels in artificial sand-binding vegetation increased with the prolongation of vegetation restoration, indicating that the succession of sand-binding vegetation will result in the ac- cumulation of soil carbon and nitrogen, as well as the restoration of soil fertility.

Analysis of cooperation equilibrium of participants in power battery recycling chains considering information barrier

In the era of large-scale retirement of power batteries,there are information barriers and high recovery costs in their recycling.In view of this,in this study we constructed a tripartite evolutionary game model of the cooperation between power battery production and recycling enterprises and government participation.We analyzed the strategic choice of the three parties in the process of power battery recycling and simulated the influence of participants'willingness and information barriers on the strategic choices of the parties.The results showed that power battery production and recycling enterprises,and the government are affected by each other's willingness to participate at different degrees.The willingness of power battery manufacturers and recycling enterprises to cooperate with each other decreased with increases in information barriers.By analyzing the impact of information barrier on power battery recycling,some suggestions are put forward to provide decision-making reference for promoting the sustainable development of power battery industry.

Development of rapid nucleic acid assays based on the recombinant polymerase amplification for monkeypox virus

Dear Editor,Monkeypox virus(MPXV),an enveloped double-stranded DNA virus with 190 open-reading frames and a genome length of about 200 kb,belongs to the genus Orthomyxovirus(OPXV;subfamily Chordopoxvirinae,family Poxviridae),which causes a disease with symptoms similar to,but less severe than,smallpox.MPXV is subdivided into two clades:clade I for the former Congo Basin clade and clade II for the former West African,and the clade I is more pathogenic.The clade II consists two subclades,clade IIa and clade IIb,with the latter referring primarily to the group of variants largely circulating in the 2022 global outbreak(ICTV,2022;Bunge et al.,2022;Mauldin et al.,2022).

Correlation of chloride diffusion coefficient and microstructure parameters in concrete: A comparative analysis using NMR,MIP, and X-CT

Permeability is a major indicator of concrete durability,and depends primarily on the microstructure characteristics of concrete,including its porosity and pore size distribution.In this study,a variety of concrete samples were prepared to investigate their microstructure characteristics via nuclear magnetic resonance(NMR),mercury intrusion porosimetry(MIP),and X-ray computed tomography(X-CT).Furthermore,the chloride diffusion coefficient of concrete was measured to explore its correlation with the microstructure of the concrete samples.Results show that the proportion of pores with diameters<1000 nm obtained by NMR exceeds that obtained by MIP,although the difference in the total porosity determined by both methods is minimal.X-CT measurements obtained a relatively small porosity;however,this likely reflcts the distribution of large pores more accurately.A strong correlation is observed between the chloride diffusion coefficient and the porosity or contributive porosity of pores with sizes<1000 nm.Moreover,microstructure parameters measured via NMR reveal a lower correlation coefficient R2 versus the chloride diffusion coefficient relative to the parameters determined via MIP,as NMR can measure non-connected as well as connected pores.In addition,when analyzing pores with sizes>50 um,X-CT obtains the maximal contributive porosity,followed by MIP and NMR.

Regional climate dynamical downscaling over the Tibetan Plateau——From quarter-degree to kilometer-scale

The Tibetan Plateau(TP)possesses the largest cryosphere in the world outside of the Arctic and Antarctic,and is the source of nine major rivers in Asia.The surface environment of the TP has undergone significant changes against the background of global warming.It is projected that the continuation of climate change in the future will result in most of the glaciers and frozen soil disappearing by the end of this century,and freshwater resources will be greatly reduced,on which 22%of the world’s population depends.These environmental changes are of great concern to global society given the influences of the TP on the climate at the global scale.However,great uncertainties exist in global climate simulations over the TP,which affects our ability to properly understand the associated water security crisis.Based on atmospheric dynamics and physical processes,dynamical downscaling can characterize surface conditions more accurately than global simulations,and better simulate and predict regional or local weather and climate situations.With advances in supercomputing,the grid spacing of dynamical downscaling simulations has been continuously increasing,marching the technique into the kilometer-scale era.In this paper,the origin and development of dynamical downscaling in the TP region from the quarter-degree to kilometer scale is firstly introduced,including an assessment of the advantages and disadvantages of dynamical downscaling at the kilometer scale over the TP.Then,the main land surface factors affecting the performance of dynamical downscaling over the TP are described,as well as a brief introduction to a land surface model with specific plateau characteristics.Specifically,it has emerged that perfecting the land surface model and improving the performance of land-atmosphere interaction are the most effective ways to advance the performance of dynamic downscaling in this region.Finally,the challenges and some recommended future research directions are discussed and proposed.