摘要：Finding crystals with high birefringence(Δn),especially in deep-ultraviolet(DUV)regions,is important for developing polarization devices such as optical fiber *** materials are usually discovered using experimental techniques,which are costly and inefficient for a large-scale ***,we collected a database of crystal structures and their optical properties and trained atomistic line graph neural network to predict theirΔ*** estimate the level of confidence of the trained model on new data,D-optimality criterion was *** trained graph neural network,we searched for novel materials with highΔn in the Materials Project database and discovered two new DUV birefringent candidates:NaYCO_(3)F_(2) and SClO_(2)F,with highΔn values of 0.202 and 0.101 at 1064 nm,*** analysis reveals that strongly anisotropic units with various anions andπ-conjugated planar groups are beneficial for highΔn.

摘要：Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models were used to evaluate and quantify the impact of global SST(from reanalysis data)on the early winter Arctic warming during *** sets of experiments were designed:in the first set(EXP1),OISSTv2 daily sea-ice concentration and SST variations were used as the lower boundary forcing,while in the second set(EXP2)the SST data were replaced by the daily SST *** the results,the multi-model ensemble mean of EXP1 showed a nearsurface(~850 hPa)warming trend of 0.4℃/10 yr,which was 80%of the warming trend in the *** simulated warming trend was robust across the six models,with a magnitude of 0.36-0.50℃/10 *** global SST could explain most of the simulated warming trend in EXP1 in the mid and low troposphere over the Arctic,and accounted for 58%of the simulated near-surface *** results also suggest that the uppertropospheric warming(~200 hPa)over the Arctic in the reanalysis is likely not a forced signal;rather,it is caused by natural climate *** source regions that can potentially impact the early winter Arctic warming are explored and the limitations of the study are discussed.

摘要：Perovskite SrTaO_(2)N is one of the most promising narrow-bandgap photocatalysts for Z-scheme overall water ***,the formation of defect states during thermal nitridation severely hinders the separation of charges,resulting in poor photocatalytic *** the present study,we successfully synthesize SrTaO_(2)N photocatalyst with low density of defect states,uniform morphology and particle size by flux-assisted one-pot nitridation combined with Mg *** important parameters,such as the size of unit cell,the content of nitrogen,and microstructure,prove the successful doping of *** defect-related carrier recombination has been significantly reduced by Mg doping,which effectively promotes the charge ***,Mg doping induces a change of the band edge,which makes proton reduction have a stronger driving *** modifying with the core/shell-structured Pt/Cr_(2)O_(3)cocatalyst,the H_(2)evolution activity of the optimized SrTaO_(2)N:Mg is 10 times that of the undoped SrTaO_(2)N,with an impressive apparent quantum yield of 1.51%at 420 *** coupling with Au-FeCoO_(x)modified BiVO_(4)as an O_(2)-evolution photocatalyst and[Fe(CN)_(6)]_(3)−/[Fe(CN)_(6)]_(4)−as the redox couple,a redox-based Z-scheme overall water splitting system is successfully constructed with an apparent quantum yield of 1.36%at 420 *** work provides an alternative way to prepare oxynitride semiconductors with reduced defects to promote the conversion of solar energy.

摘要：Knowledge Sharing and Service is one effective way to eliminate knowledge poverty and promote social *** knowledge sharing and service is mainly provided in some organizations or specific social ***,a knowledge sharing and service system about geography,natural resources and ecology has not been *** proposed a public welfare professional knowledge-sharing and service platform for all members of society in geography,natural resources and *** construction of a knowledge-sharing and service platform is based on five aspects of work：analysis of user requirements,setting standards and drafting policies,aggregating knowledge resources,the technical realization and the maintenance of *** resources can be aggregated by using a＂two-step＂strategy.A knowledge-sharing and service system can be implemented by using＂four-tier＂structures that are comprised of resources,resource access,application and service,based on the Hadoop-distributed cluster *** has been proven that adhering to the idea of co-building and co-sharing,and using the mechanism of＂payment is equal to benefit＂can effectively promote the gathering of knowledge resources,and arouse the enthusiasm of all members of society to participate in knowledge sharing and service,to achieve the objective of narrowing the knowledge gap between social groups.

摘要：Exploring the water yield and soil conservation in the Three-River-Source region is of great significance for evaluating both the ecological stability of the Qinghai-Tibet Plateau,Yellow River basin,Yangtze River basin and Lancang River basin and the sustainable development of human *** data sources for this study were land use/cover data from four phases(2000,2005,2010 and 2015),daily precipitation and temperature datasets,and the 1:1000000 Chinese soil *** data were combined with vector data,such as data on settlements,roads,and rivers,along with population,economic raster datasets and CCSM4 common climate model prediction *** Three-River-Source region was taken as the study area,and four land use/cover development scenarios and two climate change scenarios were designed based on the FLUS model and the downscaling correction *** InVEST model was used to quantitatively simulate the water yield and soil erosion under different scenarios in the study area in *** results showed the following:(1)Under different land use/cover development scenarios,grassland remained the dominant land use/cover type in the Three-River-Source region,and the area ratio was always greater than 67%.(2)Under the RCP4.5 climate scenario,the annual water yield and soil erosion increased by more than 7%and 3.9%,*** the RCP8.5 climate scenario,the annual water yield and soil erosion decreased by more than 3.3%and 1.3%,respectively.(3)Climate change played a leading role in the changes in water yield and soil *** change contributed as much as 89.97%–98.00%to the change in water yield and 60.49%–95.64%to the change in the soil erosion ***,the contribution of land use/cover changes to the change in regional water yield was only 2.00%–10.03%,and the contribution of the soil erosion modulus change was 4.36%–39.91%.Therefore,the land use development strategy in the Three-River-Source region should comprehensively consider

摘要：The permafrost region is one of the most sensitive areas to climate *** global warming,the Mongolian Plateau permafrost is rapidly degrading,and its vegetation ecosystem is seriously *** address this challenge,it is essential to understand the impact of climate change on vegetation at different permafrost degradation stages on the Mongolian *** on the general permafrost distribution,in this study,we divided different permafrost regions and explored the response of vegetation to climate change at different stages of permafrost degradation by the idea of“space instead of time”from 2014 to *** results of the study showed that:(1)Normalized difference vegetation index(NDVI)values showed a decreasing trend,and the proportion of the decreasing region was in the order of sporadic permafrost region>isolated and sparse permafrost region>continuous and discontinuous permafrost regions.(2)The main controlling factors of vegetation growth in permafrost regions are different,air temperature is the main controlling factor of vegetation growth in isolated and sparse permafrost region(r=-0.736)and sporadic permafrost regions(r=-0.522),and precipitation is the main controlling factor of vegetation growth in continuous and discontinuous permafrost region(r=-0.498).(3)The response of NDVI to climate change varies at different stages of permafrost *** the early stages of permafrost degradation,increased land surface temperature(LST)and air temperature favored vegetation growth and increased vegetation cover,whereas increased precipitation impeded vegetation growth;as the permafrost degraded,increased LST and air temperature impeded vegetation growth,whereas increased precipitation promoted vegetation growth.

摘要：一般情况下,每年冬季是季节性流感高发季节,但在当前2019冠状病毒病(COVID-19)大流行期间,全球季节性流感活动呈“断崖式”下降。为应对即将到来的流感季节,亟需弄清这种前所未有的流感低水平流行的原因。本文中,我们探索了一种国家特异性推理模型,利用该模型估计中国、英国和美国这三个国家中佩戴口罩、人员流动变化(国际和国内)以及严重急性呼吸综合征冠状病毒2型(SARS-CoV-2)干扰的影响。结果发现,在这些地区增加一周佩戴口罩的干预措施,流感活动可减少11.3%~35.2%。实施一周的限制人员流动措施对国际(1.7%~6.5%)和国内社区(1.6%~2.8%)的影响较小。2020年至2021年,仅佩戴口罩这一项干预措施就可使阳性率下降13.3%至19.8%。仅人员流动变化可使阳性率降低5.2%至14.0%,其中79.8%~98.2%归因于国际旅行限制。SARS-CoV-2干扰仅在2019年至2020年具有统计学显著效应。中国北方地区及英国的阳性百分比分别降低7.6%(2.4~14.4)和10.2%(7.2~13.6)。探索所得出的结果对了解非药物干预措施和其他呼吸系统疾病背景下的流感演变有一定意义,有助于制定卫生政策,并可为公共卫生措施的个性化设计提供信息。

摘要：生态城市是一类具有经济高产生态高效的产业、系统负责社会和谐的文化、结构健康生命力强的景观的行政单元.其建设目标是通过规划、设计、管理和建设生态景观、生态产业和生态文化来实现结构耦合的合理、代谢过程的平衡和功能的可持续性.生态城市是以生态经济学、系统工程学为理论基础,通过改变生产方式、消费行为和决策手段,实现在当地生态系统承载能力范围内可持续的、健康的人类生态过程.体制整合、科技孵化、企业投资、公众参与和政府引导是生态城市发展的基本方法.清洁生产和生态产业是生态城市建设的关键.在搞好技术和管理的同时,怎样在局地和区域生态系统尺度上整合生产、消费和还原功能,建设一类和谐的生态景观,企业的空间和城市尺度应予以充分的重视.

摘要：MXene具有丰富的高电负性末端原子、较大的比表面积和较小的原子厚度等优点,已被用作前驱体制备多种纳米材料.然而,目前已报道的用于衍生金属有机框架(MOF)的MXene仅限于V_(2)CT_(x).因此,通过增加MXene和有机配体的种类,合理设计和合成新型MOF,并进一步深入探索其合成机理仍是目前面临的重要挑战.本文采用金属离子辅助转化策略,以二维Ti_(3)C_(2)T_(x)为前驱体,合成了具有非互穿SrSi2(srs)框架的基于儿茶酚的三维(3D)TiCu-HHTP(HHTP=2,3,6,7,10,11-六羟基三苯)MOF.该策略表现出了良好的普适性,Ti3C2和辅助Cu^(2+)离子可以扩展到V2C MXene和其他辅助金属离子Mn^(+)(M=Ni^(2+)、Co^(2+),Mn^(2+)和Zn^(2+)).转化机制包括从Ti3C2纳米片到辅助金属离子的电荷转移、Ti-C键断裂促进释放Ti^(4+)离子以及Ti^(4+)/Mn^(+)与HHTP之间的强螯合配位协同促进TiCu-HHTP的形成.独特的3D导电网络和丰富的氧化还原位点赋予了TiCu-HHTP-7/PPy复合柔性透明电极快速的离子/电子传输和可逆的法拉第反应.在0.02 mA cm^(-2)电流密度下,TiCu-HHTP/PPy透明电极的面积比电容值达到3.63 mF cm^(-2),明显高于纯PPy电极的面积电容值(1.79 mF cm^(-2)).TiCu-HHTP/PPy透明电容器在0.75μW cm^(-2)的功率密度下,能量密度为0.042μWh cm^(-2).

摘要：The Mongolian Plateau,a vital ecological barrier in northern China,is of great importance for studying vegetation dynamics in Mongolia against the background of climate *** studies can enhance our understanding of regional vegetation responses to global warming and contribute to the establishment of a stronger ecological barrier in northern ***,we analyzed the spatial and temporal characteristics of the NDVI(normalized difference vegetation index)in Mongolia using 8 km resolution GIMMS NDVI3g data from 1990 to 2022,along with temperature,precipitation,and elevation *** analysis and correlation methods were used to examine the relationships between the NDVI and temperature,as well as *** results showed four important aspects of these relationships.(1)The NDVI in Mongolia increased significantly from 1990 to 2022 at a rate of 0.0015 yr^(-1)(P<0.05).(2)Mongolia’s NDVI increased from 1990 to 2022 in 60.73%of the *** this total,the area with a significant increase accounted for 31.67%and was concentrated on the eastern and western *** area experiencing a significant decrease accounted for 15.67%and was mainly located on the southwestern edges.(3)The NDVI analysis revealed significant increasing trends in all regions except for those at elevations of 1500-2000 *** greatest rate of increase was observed between 500 and 1000 m,and the increasing trend weakened as elevation continued to increase before gradually becoming significant ***,the NDVI increased significantly across different slopes,and the rate of increase decreased as the slope increased.(4)From 1990 to 2022,Mongolia’s NDVI was mostly negatively correlated with *** occurred over 66.75%of the total land area,with 17.21%of the region exhibiting a significant negative correlation,mainly in the ***,the NDVI demonstrated a positive correlation with precipitation,encompassing 86.71%of the total land *** 4