检索结果-南通市图书馆

Chinese Journal of Chemistry 2024年第1期42卷 43-47页

作者： Li Wang Renwei Xiao Jingyuan Song Long-Sheng Zheng Qiwei Lang Gen-Qiang Chen Xumu Zhang Shenzhen Key laboratory of Small Molecule Drug Discovery and Synthesis Department of Chemistryand Medi-PingshanSouthern University of Science and TechnologyShenzhenGuangdong 518000China Academy for Advanced Interdisciplinary studies Southern Universityof Science and TechnologyShenzhenGuangdong 518000China Chemistry and Chemical Engineering Guangdong laboratory ShantouGuangdong 515031China

Transition metal-catalyzed asymmetric transfer hydrogenation has been proven to be a powerful approach for the synthesis of chiral ***,a highly efficient and enantioselective transfer hydrogenation of dibenzoheptaheterocyclic ketones catalyzed by an arene-tethered TsDPEN-based Rh(ll)catalyst has been successfully developed,and a variety of dibenzoheptaheterocyclic ketones were reduced by a 1.1.mixture of formic acid and DBU(1.8-diazabicyclo[5.4.0]undec-7-ene)with high yields and *** this method,the asymmetric reduction of 7,8-difluorodibenzo[b,e]thiepin-1.(6H)-one has been realized,providing the key intermediate of baloxavir marboxil with>99% yield and>99% ee at a substrate/catalyst molar ratio of 1.00.

关键词： Asymmetric transfer hydrogenation Baloxavir Chiral alcohol Enantioselectivity Heterocyclic diaryl ketone Rhodium(Ⅱ)

Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001.1.

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第1期41卷 84-96页

作者： Zhiding ZHANG Xu YUE Hao ZHOU Jun ZHU Yadong LEI Chenguang TIAN Jiangsu Key laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science&Technology(NUIST)Nanjing 210044China climate Change Research Center Institute of Atmospheric Physics(IAP)Chinese Academy of Sciences(CAS)Beijing 100029China University of Chinese Academy of Sciences Beijing 100049China State Key laboratory of Severe Weather&Key laboratory of Atmospheric Chemistry of CMA Chinese Academy of Meteorological SciencesBeijing 100081China

The pan-Arctic is confronted with air pollution transported from lower *** have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less ***,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during *** show that aerosol DRFEs increase pan-Arctic NPP by 2.1. Pg C(1..8%)yr^(-1.under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,*** all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1.,with contributions of 0.65% by natural and 0.59% by anthropogenic *** aerosols cause a positive NPP trend of 0.022% yr^(-1.following the increased fire activities in the *** contrast,anthropogenic aerosols induce a negative trend of-0.01. yr^(-1.due to reduced emissions from the middle *** trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols *** affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.

关键词： diffuse radiation fertilization effects anthropogenic aerosols natural aerosols pan-Arctic net primary productivity

Erosion-induced recovery CO_(2) sink offset the horizontal soil organic carbon removal at the basin scale

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 2019-2033页

作者： Lingxia WANG Xiaodong NIE Jiaqi LI Yaojun LIU Hui WANG Yazhe LI Zhongwu LI School of Geographic Science Hunan Normal UniversityChangsha 410081China Institute of Interdisciplinary studies Hunan Normal University and Hunan Provincial Key Laboratory for Eco-environmental Changes and Carbon Sequestration of the Dongting Lake BasinChangsha 410081China College of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and *** is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological *** study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin *** this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1.80-2020 was 1.33×1.^(8)t,displaying a decreasing trend followed by a slight *** 1.% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the *** average lateral soil organic carbon loss induced by erosion was 8.86×1.^(1.)g C in 1.80 and 1.50×1.^(1.)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1.1.g C a^(-1.occurred during erosion,primarily through sediment burial and dynamic ***,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon ***,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long ***,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.

关键词： Water erosion Sediment transfer Lateral soil carbon loss Land-atmosphere CO_(2) flux Dongting Lake Basin

Quantitative Applications of Weather Satellite Data for Nowcasting:Progress and Challenges

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2024年第3期38卷 399-413页

作者： Jun LI Jing ZHENG Bo LI Min MIN Yanan LIU Chian-Yi LIU Zhenglong LI WPaul MENZEL Timothy J.SCHMIT John L.CINTINEO Scott LINDSTROM Scott BACHMEIER Yunheng XUE Yayu MA Di DI Han LIN Innovation Centre for Fengyun Meteorological Satellite(FYSIC) National Satellite Meteorological CentreChina Meteorological AdministrationBeijing100081China School of Atmospheric Sciences and Guangdong Province Key laboratory for {1. Change and Natural Disaster studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai519082China Key laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai200241China Research Center for Environmental Changes Academia SinicaTaipei11529China Cooperative Institute for Meteorological Satellite studies University of Wisconsin-MadisonMadisonWI53706USA Sensors and Calibration Branch STAR/NESDISMadisonWI53706USA Wuxi University Wuxi214105China School of Computer Science Chengdu University of Information TechnologyChengdu610225China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China Key laboratory of Spatial Data Mining and Information Sharing of Ministry of Education National and Local Joint Engineering Research Center of Satellite Geospatial Information TechnologyFuzhou UniversityFuzhou350108China

Monitoring and predicting highly localized weather events over a very short-term period,typically ranging from minutes to a few hours,are very important for decision makers and public *** these events usually relies on radar observations through monitoring and *** advanced high-resolution imaging and sounding observations from weather satellites,nowcasting can be enhanced by combining radar,satellite,and other data,while quantitative applications of those data for nowcasting are advanced through using machine learning *** applications include monitoring the location,impact area,intensity,water vapor,atmospheric instability,precipitation,physical properties,and optical properties of the severe storm at different stages(pre-convection,initiation,development,and decaying),identification of storm types(wind,snow,hail,etc.),and predicting the occurrence and evolution of the *** observations can provide information on the environmental characteristics in the preconvection stage and are very useful for situational awareness and storm *** paper provides an overview of recent progress on quantitative applications of satellite data in nowcasting and its challenges,and future perspectives are also addressed and discussed.

关键词： weather satellite quantitative applications nowcasting pre-convection

A Review of Decadal/Interdecadal climate Variation {1. in China

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2004年第3期21卷 425-436页

作者：李崇银何金海朱锦红 State Key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 Nanjing Institute of Meteorology Nanjing 210044 Department of Atmospheric Sciences School of Physics Peking University Beijing 100871ecadal/interdecadal climate variability is an important element in the CLIVAR (Climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation have also been completed by Chinese scientists in recent years. In this paper an introduction in outline for interdecadal climate variation research in China is presented. The content includes the features of interdecadal climate variability in China global warming and interdecadal temperature variability the NAO (the North Atlantic Oscillation)/NPO (the North Pacific Oscillation) and interdecadal climate variation in China the interdecadal variation of the East Asian monsoon the interdecadal mode of SSTA (Sea Surface Temperature Anomaly) in the North Pacific and its climate impact and abrupt change feature of the climate.

Decadal/interdecadal climate variability is an important element in the CLIVAR (climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation have also been completed by Chinese scientists in recent years. In this paper, an introduction in outline for interdecadal climate variation research in China is presented. The content includes the features of interdecadal climate variability in China, global warming and interdecadal temperature variability, the NAO (the North Atlantic Oscillation)/NPO (the North Pacific Oscillation) and interdecadal climate variation in China, the interdecadal variation of the East Asian monsoon, the interdecadal mode of SSTA (Sea Surface Temperature Anomaly) in the North Pacific and its climate impact, and abrupt change feature of the climate.

关键词： decadal/interdecadal climate variation abrupt change east-Asian monsoon sea surface temperature anomaly

Efficient hydrogenolysis of fructose to 1.2-propanediol over bifunctional Ru-WO_(x)-MgO_(y) catalysts under mild reaction conditions via enhancing the chemoselective cleavage of C-C bonds

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第5期92卷 311-321页

作者： Shuang Luo Tie Shu Min Mao Haijie Yu Yuxin Zheng Daqian Ding Lingmei Liu Kexin Yao Jianjian Wang School of Chemistry and Chemical Engineering State Key Laboratory of Coal Mine Disaster Dynamics and ControlInstitute of Advanced Interdisciplinary StudiesMulti-scale Porous Materials CenterChongqing UniversityChongqing 401331China Key laboratory for Efficient Conversion and Circular Economy of Coal Chemical Engineering CollegeInner Mongolia University of TechnologyHohhot 010051Inner MongoliaChina

Selective conversion of fructose to 1.2-propanediol(1.2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low efficiency and harsh reaction ***,we have successfully synthesized a novel bifunctional Ru-WO_(x)-MgO_(y) catalyst through a facile'one-pot'solvothermal ***,this catalyst exhibits exceptional catalytic performances in the conversion of fructose to 1.2-PDO under mild reaction *** yield of 1.2-PDO is up to 56.2%at 1.0°C for 4 h under an ultra-low hydrogen pressure of only 0.2 MPa,surpassing the reported results in recent literature(below 51.).Comprehensive characterizations and density functional theory(DFT)calculations reveal that the presence of oxygen vacancies in the Ru-WO_(x)-MgO_(y) catalyst,serving as active acidic sites,facilitates the chemoselective cleavage of C-C bonds in fructose,which leads to the generation of active intermediates and ultimately resulted in the high yield of 1.2-PDO.

关键词： Biomass Fructose 1.2-Propanediol Retroaldol condensation Heterogenous catalysis

Does the Negative Arctic Oscillation Always Favor Winter PM2.5 Diffusion in North China?

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2024年第05期 954-968页

作者： Yueyue YU Zhengfei CUI Haishan CHEN Guotao LIU Chunhua SHI Jian RAO Key laboratory of Meteorological Disaster Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)Nanjing University of Information Science&Technology Department of Geography University College London (UCL)

Previous studies have reported a close relationship between the negative Arctic Oscillation（AO） and the PM2.5(particulate matter with a diameter of2.5μm or less) diffusion in North China in winter. Using the North China regional mean meridional wind at 850 hPa derived from the ERA5（ECMWF Reanalysis version 5） reanalysis data in1.79–2022 as a useful substitute for station observed PM2.5concentration（since the latter is available only since201.）, our study detected strong/weak northerly events representing the abnormal PM2.5diffusion/accumulation events, and revisited the AO–PM2.5diffusion relationship in North China during 1.79–2022. The results show that only when the AO was characterized by a 2-month continuously negative/positive phases and with twin peaks respectively before and after the diffusion/accumulation events, would there be higher occurrences of the abnormal PM2.5diffusion/*** second peak of negative AO acted to prolong the strong northerly winds by an average of 2 days. Further analysis reveals that the AO with twin peaks always has a footprint in the stratospheric northern annular mode（NAM） during the abnormal PM2.5events, and the coupling between the stratosphere and troposphere plays a critical role in the second peak of AO. Vertical propagation of baroclinically amplifying waves leads to changes in isentropic meridional mass fluxes in the stratosphere following the changes in the troposphere. The stronger/weaker poleward mass fluxes increase/decrease the polar mass in the stratosphere, which dominates the total column air mass changes and leads to the second peak of AO. Considering the subseasonal predictability of the stratospheric NAM based on existing evidence, particular attention should be paid to these AO-related abnormal PM2.5diffusion and accumulation events in North China because they might be more predictable at a longer lead time.

关键词：

The effect of long-term application of nitrogen-rich fertilizers on soil resistome:A study of conventional and organic cropping systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Soil Ecology Letters 2024年第3期6卷 135-150页

作者： Alexey S.Vasilchenko Evgenii O.Burlakov Darya V.Poshvina Denis S.Gruzdev Sergey V.Kravchenko Aleksandr V.Iashnikov Ning Ling Anastasia V.Vasilchenko laboratory of Antimicrobial Resistance Institute of Environmental and Agricultural Biology(X-BIO)Tyumen State UniversityTyumenRussia Research Institute of Mathematics Physics and Computer ScienceDerzhavin Tambov State UniversityTambovRussia International Integrated Research laboratory for {1. Change Land Use and BiodiversityInstitute of Environmental and Agricultural Biology(X-BIO)Tyumen State UniversityTyumenRussia SciBear OU Tartu Mnt 67/1-13bKesklinna Linnaosa10115 TallinnEstonia Center for Grassland Microbiome State Key Laboratory of Grassland Agro-EcosystemsCollege of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China

Metagenomic studies of various soil environments have previously revealed the widespread distribution of antibiotic resistance genes(ARGs)around the *** this study,we applied shotgun metagenomics to investigate differences in microbial communities and resistomes in Chernozem soils that have been under long-term organic and conventional cropping *** organic cropping system was seeded with Triticum spelta without any *** conventional cropping system was seeded with Tríticum durum Desf and used mineral fertilizer(NPK),that resulted in an increased amount of total and available carbon and nitrogen in *** all samples,we identified a total of 21.ARG classes,among which the dominant were vancomycin,tetracycline and *** of soil microbial communities revealed differences between the studied fields in the relative abundances of 1. and 53 genera in topsoil and subsoil,*** analysis showed significant correlations(positive and negative)among 1. genera and 6 ARGs,as well as between these ARGs and some chemical properties of *** analysis of metagenome-assembled genomes revealed that Nitrospirota,Thermoproteota,Actinobacteriota and Binatota phyla of archaea and bacteria serve as hosts for glycopeptide and fluoroquinolone/tetracycline ***,the data obtained enrich knowledge about the consequences of human agricultural activities in terms of soil microbiome modification and highlight the role of nitrogen cycling taxa,including uncultivated genera,in the formation of soil resistome.

关键词： soil microbiome inorganic fertilizer nitrogen cycle uncultured bacteria chemolithotrophs Binatia

MEIC-global-CO_(2):A new global CO_(2)emission inventory with highly-resolved source category and sub-country information

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第2期67卷 450-465页

作者： Ruochong XU Dan TONG Qingyang XIAO Xinying QIN Cuihong CHEN Liu YAN Jing CHENG Can CUI Hanwen HU Wenyu LIU Xizhe YAN Huaxuan WANG Xiaodong LIU Guannan GENG Yu LEI Dabo GUAN Kebin HE Qiang ZHANG Department of Earth System Science Ministry of Education Key Laboratory for Earth System ModelingInstitute for Global Change StudiesTsinghua UniversityBeijing100084China State Key Joint laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Chinese Academy of Environmental Planning Beijing100041China Institute for Carbon Neutrality Tsinghua UniversityBeijing100084China

CO_(2)emission inventory provides fundamental data for climate research and emission ***,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(IEA)and were available at country level with limited source ***,as the first step toward a high-resolution and dynamic updated global CO_(2)emission database,we developed a data-driven approach to construct seamless and highly-resolved energy consumption data cubes for 208 countries/territories,797 sub-country administrative divisions in 29 countries,42 fuel types,and 52 sectors,with the fusion of activity data from 24 international statistics and 65 regional/local *** CO_(2)emissions from fossil fuel combustion and cement production in 1.70–2021.were then estimated with highly-resolved source category(1.484 of total)and sub-country information(797 of total).Specifically,73%of global CO_(2)emissions in 2021.were estimated with sub-country information,providing considerably improved spatial resolution for global CO_(2)emission *** the support of detailed information,the dynamics of global CO_(2)emissions across sectors and fuel types were presented,representing the evolution of global economy and progress of climate *** differences of sectoral contribution were found across sub-country administrative divisions within a given country,revealing the uneven distribution of energy and economic structure among different *** estimates were generally consistent with existing databases at aggregated level for global total or large emitters,while large discrepancies were observed for middle and small *** database,named the Multiresolution Emission Inventory model for climate and air pollution research(MEIC)is publicly available through http://*** with highly-resolved information and timely update,which provides an independent carbon emission accounting data source for climate rese

关键词： CO_(2)emissions Data-driven approach Highly-resolved source category Sub-country information

Intrinsic polarization conversion and avoided-mode crossing in X-cut lithium niobate microrings

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第6期33卷 398-403页

作者：谭泽林张检发朱志宏陈伟邵铮铮刘肯秦石乔 College of Advanced Interdisciplinary studies&Hunan Provincial Key {1. of Novel Nano Optoelectronic Information Materials and Devices National University of Defense TechnologyChangsha 410073China Nanhu Laser laboratory National University of Defense TechnologyChangsha 410073China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China School of Physics Central South UniversityChangsha 410083China

Compared with well-developed free space polarization converters, polarization conversion between TE and TM modes in the waveguide is generally considered to be caused by shape birefringence, like curvature, morphology of waveguide cross section and scattering. Here, we study the polarization conversion mechanism in 1.THz-FSR X-cut lithium niobate microrings with multiple-resonance condition, that is the conversion can be implemented by birefringence of waveguides,which will also introduce an avoided-mode crossing. In the experiment, we find that this mode crossing results in severe suppression of one sideband in local nondegenerate four-wave mixing and disrupts the cascaded four-wave mixing on this side. Simultaneously, we propose one two-dimensional method to simulate the eigenmodes(TE and TM) in X-cut microrings, and the mode crossing point. This work will provide one approach to the design of polarization converters and simulation for monolithic photonics integrated circuits, and may be helpful to the studies of missed temporal dissipative soliton formation in X-cut lithium niobate rings.

关键词： polarization conversion birefringence nondegenerate four-wave mixing