检索结果-南通市图书馆

Spatially explicit reconstruction of cropland cover in Europe from AD 1800 to 2000

Science china Earth Sciences 2024年第9期67卷 2953-2971页

作者： Jun LI Yu YE Xiuqi FANG Diyang ZHANG Zhilei WU Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China key Laboratory of Environmental Change and Natural Disaster Ministry of EducationBeijing Normal UniversityBeijing 100875China College of Geographical Science Qinghai Normal UniversityXining 810016China

One of the challenges in global change research is the significant uncertainty in global historical land use and land cover(LUCC)datasets,which are widely used as foundational *** addition to the regional cropland area reconstructions,improving the grid allocation method is another feasible way to raise the reliability of historical LUCC *** this study,an integrated reconstruction of the national cropland areas over the past 200 years was developed for 36 European *** that,the allocation algorithm was built using physiogeographic variables and historical city sites for accounting for land suitability and cultivation preferences,***,cropland data in Europe with a spatial resolution of 5′×5′at five time sections from AD 1800 to 2000 were generated using the optimal allocation algorithm in accordance with the stages of the regional *** results were as follows:(1)The dominant factors governing the distribution of croplands in Europe vary at different agricultural stages,but the results can be merged *** suitability was more optimal for allocation during the modern agricultural stage(AD 1950 and 2000);the priority index combined with land suitability and cultivation preference was more reasonable for allocation during the traditional agricultural stage(AD 1800).The average of the allocations by priority index and the land suitability could be adopted as the allocation results during the transitional stage(AD 1850 and 1900)because the grids for absolute differences within±10 and±20 percentage points between the results obtained from the above two allocations were above 80% and 95%,respectively,which means the two allocation results could be merged.(2)Over the past 200 years,the total cropland area in Europe first increased to a peak in AD 1900 and then ***,the centre of the higher cropland fraction shifted from the western part of Europe in AD 1800 to the eastern part of the continent after AD 1950.(3)

关键词： Land use and land cover change Historical cropland Gridding allocation Europe Past 200 years

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

过去千年黄河中下游地区耕地覆被变化定量重建

引用

Journal of Geographical Sciences 2024年第5期34卷 921-941页

作者：杨帆张航何凡能王亚非周胜男董冠鹏 key research Institute of Yellow River Civilization and Sustainable development Henan UniversityKaifeng 475001HenanChina key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China

Landscape in the middle and lower reaches of the Yellow River in china has un-dergone significant changes for thousands of years due to agricultural *** of reliable long-term and high-resolution historical cropland data has limited our ability in un-derstanding and quantifying human impacts on regional climate change,carbon and water *** this study,we used a data-driven modeling framework that combined multiple sources of data(historical provincial cropland area,historical coastlines,and satellite da-ta-based maximum cropland extent)with a new gridding allocation model for croplands dis-tribution to reconstruct a historical cropland dataset for the middle and lower reaches of the Yellow River at a 10-km resolution for 58 time points ranging from the period 1000 to *** cropland area in the study area increased by 2.3 times from 21.87 million ha in 1000 to 50.64 million ha in *** 1393,the area of cropland increased slowly and was pri-marily concentrated in the Weihe and Fenhe *** 1393-1820,the area of cropland increased rapidly,particularly on the North china *** 1820,cropland cover has tended to become *** newly reconstructed results agreed well with remotely sensed data as well as historical document-based facts regarding cropland distribution.

关键词： land use/cover change gridding allocation cropland cover last millennium

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intermolecular Acid-Base-Pairs Containing Poly(p-Terphenyl-co-Isatin Piperidinium) for High Temperature Proton Exchange Membrane Fuel Cells

引用

Energy & Environmental Materials 2024年第3期7卷 410-418页

作者： Xiaofeng Hao Zhen Li Min Xiao Zhiheng Huang Dongmei Han Sheng Huang Wei Liu Shuanjin Wang Yuezhong Meng The key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Materials Science and EngineeringSun Yat-sen University School of Chemical Engineering and Technology Sun Yat-sen University Institute of Chemistry Henan Provincial Academy of Sciences research Center of Green Catalysts College of ChemistryZhengzhou University

How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane （HT-PEMs） fuel cell are significant ***,bifunctional poly （p-terphenyl-co-isatin piperidinium） copolymer with tethered phosphonic acid （t-PA） and intrinsic tertiary amine base groups are firstly prepared and investigated as *** distinctive architecture of the copolymer provides a well-designed platform for rapid proton *** not only transports through the hydrogen bond network formed by the adsorbed free phosphoric acid （f-PA）anchored by the tertiary amine base groups,but also rely upon the proton channel constructed by the ionic cluster formed by the t-PA *** the design of the structure,the bifunctional copolymers with lower PA uptake level （<100%） display prominent proton conductivities and peak power densities (99 mS cm-1,812 mW cm-2at 160℃),along with lower PA leaching and higher voltage stability,which is a top leading result in disclosed *** results demonstrate that the design of intermolecular acid-base-pairs can improve the proton conductivity without sacrificing the intrinsic chemical stability or mechanical property of the thin membrane,realizing win-win demands between the mechanical robustness and electrochemical properties of HT-PEMs.

关键词： bifunctional copolymer high temperature proton exchange membrane intermolecular acid–base-pairs phosphonic acid retention phosphonic acid uptake level

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Comprehensive Risk Assessment of Sea Level Rise and Tropical Cyclones in Dongzhaigang Mangroves,china

引用

Chinese Geographical Science 2024年第4期34卷 631-646页

作者： DING Ruyi CAI Rongshuo YAN Xiuhua LI Cuihua WANG Cui NIE Xinyu Third Institute of Oceanography Ministry of Natural ResourcesXiamen 361005China

Mangroves play a pivotal role in tropical and subtropical coastal ecosystem,yet they are highly vulnerable to the effects of climate change,particularly the accelerated global sea level rise(SLR)and stronger tropical cyclones(TCs).However,there is a lack of research addressing future simultaneous combined impacts of the slow-onset of SLR and rapid-onset of TCs on china's *** order to develop a comprehensive risk assessment method considering the superimposed effects of these two factors and analyze risk for mangroves in Dongzhaigang,Hainan Island,china,we used observational and climate model data to assess the risks to mangroves under low,intermediate,and very high greenhouse gas(GHG)emission scenarios(such as SSP1-2.6,SSP2-4.5,and SSP5-8.5)in 2030,2050,and 2100,and compiled a risk assessment scheme for mangroves in Dongzhaigang,*** results showed that the combined risks from SLR and TCs will continue to rise;however,SLRs will increase in intensity,and TCs will *** comprehensive risk of the Dongzhaigang mangroves posed by climate change will remain low under SSP1-2.6 and SSP2-4.5 scenarios by 2030,but it will increase substantially by *** under SSP5-8.5 scenario,the risks to mangroves in Dongzhaigang are projected to increase considerably by 2050,and approximately 68.8%of mangroves will be at very high risk by *** risk to the Dongzhaigang mangroves is not only influenced by the hazards but also closely linked to their exposure and *** therefore propose climate resilience developmental responses for mangroves to address the effects of climate *** study for the combined impact of TCs and SLR on mangroves in Dongzhaigang,china can enrich the method system of mangrove risk assessment and provide references for scientific management.

关键词： mangrove climate change risk assessment combined hazards sea level rise(SLR) tropical cyclones(TCs) resilience development Dongzhaigang china

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spin logic devices based on negative differential resistance -enhanced anomalous Hall effect

引用

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1437-1448页

作者： Hongming Mou Ziyao Lu Yuchen Pu Zhaochu Luo Xiaozhong Zhang key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China State key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China

Owing to rapid developments in spintronics,spin-based logic devices have emerged as promising tools for next-generation computing *** paper provides a comprehensive review of recent advancements in spin logic devices,particularly focusing on fundamental device concepts rooted in nanomagnets,magnetoresistive random access memory,spin–orbit torques,electric-field modu-lation,and magnetic domain *** operation principles of these devices are comprehensively analyzed,and recent progress in spin logic devices based on negative differential resistance-enhanced anomalous Hall effect is *** devices exhibit reconfigur-able logic capabilities and integrate nonvolatile data storage and computing *** current-driven spin logic devices,negative differential resistance elements are employed to nonlinearly enhance anomalous Hall effect signals from magnetic bits,enabling reconfig-urable Boolean logic ***,voltage-driven spin logic devices employ another type of negative differential resistance ele-ment to achieve logic functionalities with excellent cascading *** cascading several elementary logic gates,the logic circuit of a full adder can be obtained,and the potential of voltage-driven spin logic devices for implementing complex logic functions can be *** review contributes to the understanding of the evolving landscape of spin logic devices and underscores the promising pro-spects they offer for the future of emerging computing schemes.

关键词： spin logic spin–orbit torque negative differential resistance full-adder

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Boost the Utilization of Dense FeN_(4) Sites for High-Performance Proton Exchange Membrane Fuel Cells

引用

Energy & Environmental Materials 2024年第3期7卷 398-405页

作者： Yanrong Li Shuhu Yin Long Chen Xiaoyang Cheng Chongtai Wang Yanxia Jiang Shigang Sun State key Laboratory of Physical Chemistry of Solid Surfaces Engineering Research Center of Electrochemical Technologies of Ministry of EducationCollege of Chemistry and Chemical Engineering and Discipline of Intelligent Instrument and EquipmentXiamen UniversityXiamen 361005China College of Chemistry and Chemical Engineering Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan ProvinceHainan Normal UniversityHaikou 571158China

Iron-nitrogen-carbon(Fe-N-C)catalysts for the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs)have seriously been hindered by their poor ORR performance of Fe-N-C due to the low active site density(SD)and site ***,we reported a melamine-assisted vapor deposition approach to overcome these *** melamine not only compensates for the loss of nitrogen caused by high-temperature pyrolysis but also effectively etches the carbon substrate,increasing the external surface area and mesoporous porosity of the carbon *** can provide more useful area for subsequent vapor deposition on active *** prepared 0.20Mela-FeNC catalyst shows a fourfold higher SD value and site utilization than the FeNC without the treatment of *** a result,0.20Mela-FeNC catalyst exhibits a high ORR activity with a half-wave potential(E_(1/2))of 0.861 V and 12-fold higher ORR mass activity than the FeNC in acidic *** the cathode in a H_(2)-O_(2)PEMFCs,0.20Mela-FeNC catalyst demonstrates a high peak power density of 1.30 W cm^(-2),outstripping most of the reported Fe-N-C *** developed melamine-assisted vapor deposition approach for boosting the SD and utilization of Fe-N-C catalysts offers a new insight into high-performance ORR electrocatalysts.

关键词： fuel cells melamine oxygen reduction reaction site density utilization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Independent dual beams generated by array element division in integrated optical phased arrays

引用

Chinese Optics Letters 2024年第7期22卷 35-41页

作者： Guihan Wu Yu Xin Lemeng Leng Xiang Ji Shichong Yang Kaifei Tang Quan Luo Hongsheng Luo Jinshan Su Wei Jiang College of Engineering and Applied Sciences Nanjing UniversityNanjing 210023China national Laboratory of Solid-State Microstructures Nanjing 210093China key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of EducationNanjing UniversityNanjing 210023China Jiangsu key Laboratory of Artificial Functional Materials Nanjing UniversityNanjing 210023China key Laboratory of Vibration Signal Capture and Intelligent Processing Yili Normal UniversityIli 835000China

Optical phased arrays(OPAs)have broad application prospects due to their advanced capability in beamforming and *** this work,we achieve independent dual beams in the far field by dividing the array elements of the OPA,with the maximum scanning range reaching 100°.Based on the working principle of OPAs,theoretical considerations of such multibeam generation are presented.A phase data allocation approach for OPAs in the presence of fabrication-induced random phase variation is *** of large ensembles of OPAs with various levels of random residual phase errors have been conducted to help analyze the *** approach can help OPAs realize multi-beams for light detection and ranging(LiDAR).

关键词： optical phased arrays beamforming phase error calibration array element division.D01:10.3788/COL202422.071301

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stable α-CsPbI3 with extremely red emission for expanding the color gamut

引用

Science china(Information Sciences) 2024年第5期67卷 311-317页

作者： Yong ZHANG Xin WEI Lei GAO Weijie ZHAO Changjiu SUN Junli WEI Mingjian YUAN Zhenhua NI Junpeng LU Hongwei LIU School of Physics and key Laboratory of MEMS of the Ministry of Education Southeast University key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Renewable Energy Conversion and Storage Center (RECAST) College of Chemistry Nankai University Jiangsu key Lab on Opto-Electronic Technology School of Physics and TechnologyNanjing Normal University

The wider color gamut represents the better reproducibility of the real natural colors. Perovskite materials exhibit promising potential in full-color wide-gamut displays because of the wide tunability and high saturability of their photon emission. However, the full-color wide gamut(>100% Rec.2020) has not been constructed due to the lack of the extreme red primary color(～700 nm). Herein, the widest color gamut is realized, whereinα-CsPbI3 is used to generate the extreme red primary color. An in-situ encapsulation approach is advised to stabilizeα-CsPbI3 at room temperature by means of polyvinylpyrrolidone(PVP).Theα-CsPbI3 encapsulated by PVP(denoted as P-CPI) shows highly saturated(FWHM(full width at half maximum) ～28 nm) and extremely(～697 nm) red emission. The green emission is provided by P-CPBr(CsPbBr3 with PVP) which is also synthesized using the universal in-situ encapsulation approach. With the assistance of a commercial Ga N chip, the RGB gamut is extended to the widest(151% NTSC, 113%Rec.2020).

关键词： all-inorganic perovskite wide color gamut LED display carrier recombination

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Quantized anomalous Hall resistivity achieved in molecular beam epitaxy-grown Mn Bi2Te4 thin films

引用

national Science Review 2024年第2期11卷 24-32页

作者： Yunhe Bai Yuanzhao Li Jianli Luan Ruixuan Liu Wenyu Song Yang Chen Peng-Fei Ji Qinghua Zhang Fanqi Meng Bingbing Tong Lin Li Yuying Jiang Zongwei Gao Lin Gu Jinsong Zhang Yayu Wang Qi-Kun Xue Ke He Yang Feng Xiao Feng State key Laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University Institute of Physics Chinese Academy of Sciences School of Materials Science and Engineering Tsinghua University Beijing Academy of Quantum Information Sciences Frontier Science Center for Quantum Information Hefei national Laboratory Southern University of Science and Technology

The intrinsic magnetic topological insulator MnBi2Te4provides a feasible pathway to the high-temperature quantum anomalous Hall（QAH） effect as well as various novel topological quantum phases. Although quantized transport properties have been observed in exfoliated MnBi2Te4thin flakes, it remains a big challenge to achieve molecular beam epitaxy（MBE）-grown MnBi2Te4thin films even close to the quantized regime. In this work, we report the realization of quantized anomalous Hall resistivity in MBE-grown MnBi2Te4thin films with the chemical potential tuned by both controlled in situ oxygen exposure and top gating. We find that elongated post-annealing obviously elevates the temperature to achieve quantization of the Hall resistivity, but also increases the residual longitudinal resistivity, indicating a picture of high-quality QAH puddles weakly coupled by tunnel barriers. These results help to clarify the puzzles in previous experimental studies on MnBi2Te4and to find a way out of the big difficulty in obtaining MnBi2Te4samples showing quantized transport properties.

关键词： intrinsic magnetic topological insulator quantized anomalous Hall resistivity molecular beam epitaxy quantized transport property

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Searching for^(76)Ge neutrinoless double beta decay with the CDEX-1B experiment

引用

Chinese Physics C 2024年第10期48卷 11-22页

作者： Bing-Tao Zhang Jun-Zheng Wang Li-Tao Yang Qian Yue Ke-Jun Kang Yuan-Jing Li Hai-Peng An C.Greeshma Jian-Ping Chang Yun-Huan Chen Jian-Ping Cheng Wen-Han Dai Zhi Deng Chang-Hao Fang Xin-Ping Geng Hui Gong Qiu-Ju Guo Xu-Yuan Guo Li He Sheng-Ming He Jin-Wei Hu Han-Xiong Huang Tu-Chen Huang Hai-Tao Jia Xi Jiang S.Karmakar Hao-Bin Li Jian-Min Li Jin Li Qian-Yun Li Ren-Ming-Jie Li Xue-Qian Li Yu-Lan Li Yi-Fan Liang Bin Liao Fong-Kay Lin Shin-Ted Lin Jia-Xuan Liu Shu-Kui Liu Yan-Dong Liu Yu Liu Yuan-Yuan Liu Zhong-Zhi Liu Hao Ma Yu-Cai Mao Qi-Yuan Nie Jin-Hua Ning Hui Pan Ning-Chun Qi Jie Ren Xi-Chao Ruan Ze She Manoj Kumar Singh Tian-Xi Sun Chang-Jian Tang Wei-You Tang Yang Tian Guang-Fu Wang Li Wang Qing Wang Yu-Feng Wang Yun-Xiang Wang Henry-Tsz-King Wong Shi-Yong Wu Yu-Cheng Wu Hao-Yang Xing Rui Xu Yin Xu Tao Xue Yu-Lu Yan Nan Yi Chun-Xu Yu Hai-Jun Yu Jian-Feng Yue Ming Zeng Zhi Zeng Feng-Shou Zhang Lei Zhang Zhen-Hua Zhang Zhen-Yu Zhang Kang-Kang Zhao Ming-Gang Zhao Ji-Fang Zhou Zu-Ying Zhou Jing-Jun Zhou key Laboratory of Particle and Radiation Imaging(Ministry of Education)and Department of Engineering Physics Tsinghua UniversityBeijing 100084 Department of Physics Tsinghua UniversityBeijing 100084 Institute of Physics Academia SinicaTaipei 11529 NUCTECH Company Beijing 100084 YaLong River Hydropower development Company Chengdu 610051 College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875 College of Physics Sichuan UniversityChengdu 610065 School of Physics Peking UniversityBeijing 100871 Department of Nuclear Physics China Institute of Atomic EnergyBeijing 102413 Sino-French Institute of Nuclear and Technology Sun Yat-sen UniversityZhuhai 519082 School of Physics Nankai UniversityTianjin 300071 Department of Physics Banaras Hindu UniversityVaranasi 221005 Department of Physics Beijing Normal UniversityBeijing 100875

We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the china Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of^(76)Ge.A total of 504.3 kg⋅day effective exposure data was *** anti-coincidence and the multi/single-site event(MSE/SSE)discrimination methods were used to suppress the background in the energy region of interest(ROI,1989–2089 keV for this work)with a factor of 23.A background level of 0.33 counts/(keV⋅kg⋅yr)was *** lower limit on the half life of^(76)Ge 0νββdecay was constrained as T_(1/2)^(0ν)>1.0×10^(23)yr(90%C.L.),corresponding to the upper limits on the effective Majorana neutrino mass:<3.2–7.5 eV.

关键词： neutrinoless double beta decay CDEX point-contact germanium detector ^(76)Ge

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：