检索结果-南通市图书馆

维普期刊数据库博看期刊

Apply Spatially Variant Apodization to SAR/INSAR Image Processing

在线全文

学校读者我要写书评

暂无评论

Apply Spatially Variant Apodization to SAR/INSAR Image Proce...

Spatial-Temporal Changes in Grain Production, Consumption and Driving Mechanism in china

2007 Asian and Pacific Conference on Synthetic Aperture Radar(APSAR 2007)

作者： Wenshuai zhai Yunhua Zhang Center for Space Science and Applied Research chinese academy of sciences beijing 100080

Spatially Variant Apodization （SVA） is one of nonlinear apodization methods used for sidelobe control in SAR/ISAR or optical imagery while maintaining mainlobe resolution unchanged. In this paper,we apply SVA to process RADARSAT image and show that by using SVA one can get better resolution compared with using classic windowing techniques such as Hamming,etc. Also,we investigate the impact of SVA for phase sensitive applications and find that SVA can be used to enhance coherence of image pair for INSAR. SIR-C/X X-band experimental data are processed to demonstrate the significant effect of SVA.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2013年第2期12卷 374-385页

作者： XU Shi-wei WU Jian-zhai SONG Wei LI Zhi-qiang LI Zhe-min KONG Fan-tao Key Laboratory of Digital Agricultural Early-Warning Technology Ministry of Agriculture/Agriculture Information Institute Chinese Academy of Agriculture Sciences Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences

The spatial-temporal patterns of grain production and consumption have an important influence on the effective national grain supply on condition of tight balance in the total grain amount in china. In this paper, we analyze the spatial-temporal pattems of grain production, consumption and the driving mechanism for their evolution processes in china. The results indicate that both gravity centers of grain production and consumption in china moved toward the northern and eastern regions, almost in the same direction. The coordination of grain production and consumption increased slightly from 1995 to 2007 but decreased from 2000 to 2007. There is a spatial difference between the major districts of output increase and the strong growth potential in grain consumption, which indicates an increasing difficulty in improving the regional coordination of grain production and consumption. The movement of the gravity center of grain production is significantly correlated with regional differences in grain production policy, different economic development models, and spatial disparity of land and water resource use. For grain consumption, the main driving factors include rapid urbanization, the upgrade of food consumption structure, and distribution of food industries.

关键词： grain production grain consumption gravity center driving mechanism

维普期刊数据库

Discovery of scheelite in the Zaozigou gold deposit of West Qinling Orogen,Northwest china and its implications for ore genesis

在线全文

学校读者我要写书评

暂无评论

china Geology 2024年第3期7卷 586-588页

作者： Meng-xu Guo Jia-jun Liu De-gao zhai Guo-ming Weng Rui Zhu State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences and ResourcesChina University of Geosciences(Beijing)Beijing 100083China Zaozigou Gold Mine Zhaojin Mining Industry Co.Ltd.Hezuo 747000China

*** The West Qinling Orogen extends east-west over 1500 km and is endowed with dozens of large-super large scale gold *** Zaozigou gold deposit has a proven reserve of 134 t with an average grade of 3.08 g/t thus is one of the largest deposits in the West Qinling ***,whether the fluid type is metamorphic or magmatichydrothermal and ore-formation processes of the Zaozigou gold deposit are *** is a ubiquitous accessory mineral in geologically diverse ore-deposit types and attested to be a strong indicator of ore-forming conditions and oredeposit genesis.

关键词： deposit gold Qinling

维普期刊数据库

Irrigation and nitrogen fertiliser optimisation in protected vegetable fields of northern china:Achieving environmental and agronomic sustainability

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第3期23卷 1022-1033页

作者： Bingqian Fan Yitao Zhang Owen Fenton Karen Daly Jungai Li Hongyuan Wang Limei zhai Xiaosheng Luo Qiuliang Lei Shuxia Wu Hongbin Liu State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern china/Key Laboratory of Nonpoint Source Pollution Control Ministry of Agriculture and Rural Affairs/lnstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Institute of Geographic sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Teagasc Environmental Research CentreWexford Y35Ireland Institute of Plant Nutrition Resources and Environmental SciencesHenan Academy of Agricultural SciencesZhengzhou 450002China

Globally,sub-optimal use of nitrogen (N) fertiliser and elevated N irrigation groundwater have led to high leached nitrate (NO_(3)^(–)) losses from protected vegetable field *** fertiliser and irrigation management in different soil types is crucial to reduce future N loads from such *** present 4-year study examined leached N loads from lysimeter monitoring arrays set up across 18 protected vegetable system sites encompassing the dominant soil types of northern *** treatments applied at each field site were:1) a high N and high irrigation input treatment (HNHI);2) a low N but high irrigation input treatment (LNHI) and 3) a low N with low irrigation input treatment (LNLI).Results showed that the mean annual leached total nitrogen loads from the HNHI,LNHI and LNLI treatments were 325,294 and 257 kg N ha^(–1) in the fluvo-aquic soil,114,100 and 78 kg N ha^(–1) in the cinnamon soil and 79,68 and 57 kg N ha^(–1) in the black soil,*** N dissolved in irrigation water in the fluvo-aquic soil areas was 8.26-fold higher than in the cinnamon areas.A structural equation model showed that N fertiliser inputs and leaching water amounts explained 14.7 and 81.8%of the variation of leached N loads,***,reducing irrigation water by 21.5%decreased leached N loads by 20.9%,while reducing manure N and chemical N inputs by 22 and 25%decreased leached N loads by only 9.5%. This study highlights that protected vegetable fields dominated by fluvo-aquic soil need management to curtail leached N losses in northern china.

关键词： agriculture water quality nitrate groundwater irrigation management

维普期刊数据库

Electrochemical CO_(2)reduction to C_(2+)products over Cu/Zn intermetallic catalysts synthesized by electrodeposition

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2024年第1期18卷 80-88页

作者： Ting DENG Shuaiqiang JIA Shitao HAN Jianxin zhai Jiapeng JIAO Xiao CHEN Cheng XUE Xueqing XING Wei XIA Haihong WU Mingyuan HE Buxing HAN School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200062China Institute of Eco-Chongming Shanghai 202162China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China

Electrocatalytic CO_(2)reduction(ECR)offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO_(2)as the ***,the lack of cost-effective electrocatalysts with better performances has seriously hindered its ***,a one-step co-electrodeposition method was used to introduce Zn,a metal with weak^(*)CO binding energy,into Cu to form Cu/Zn intermetallic catalysts(Cu/Zn IMCs).It was shown that,using an H-cell,the high Faradaic efficiency of C_(2+)hydrocarbons/alcohols()could be achieved in ECR by adjusting the surface metal components and the applied *** suitable conditions,FEC_(2+)and current density could be as high as 75%and 40 mA/cm^(2),*** with the Cu catalyst,the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area(ECSA),which accelerate the ***,the^(*)CO formed on Zn sites can move to Cu sites due to its weak binding with*CO,and thus enhance the C–C coupling on the Cu surface to form C_(2+)products.

关键词： carbon dioxide electroreduction electrochemistry co-electrodeposition intermetallic catalysts value-added chemicals

The“depict”strategy for discovering new compounds in complex matrices:Lycibarbarspermidines as a case

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

Journal of Pharmaceutical Analysis 2024年第3期14卷 416-426页

作者： Chen Han Zhixin Zhang Zhiyang Feng Chuanjia zhai Xuejiao Li Yulian Shi Xiang Li Miao Li Ying Wang Gan Luo Xiaoyan Gao Department of chinese Medicine Analysis School of Chinese Materia MedicaBeijing University of Chinese MedicineBeijing102488China

The comprehensive detection and identification of active ingredients in complex matrices is a crucial *** chromatography coupled with high-resolution mass spectrometry(LC-HRMS)is the most prominent analytical platform for the exploration of novel active compounds from complex ***,the LC-HRMS-based analysis workflow suffers from several bottleneck issues,such as trace content of target compounds,limited acquisition for fragment information,and uncertainty in interpreting relevant MS2 *** are vital antioxidant active ingredients in Lycii Fructus,while the reported structures are merely focused on dicaffeoylspermidines due to their low *** comprehensively detect the new structures of lycibarbarspermidine derivatives,a“depict”strategy was developed in this ***,potential new lycibarbarspermidine derivatives were designed according to the biosynthetic pathway,and a comprehensive database was established,which enlarged the coverage of lycibarbarspermidine ***,the polarity-oriented sample preparation of potential new compounds increased the concentration of the target ***,the construction of the molecular network based on the fragmentation pathway of lycibarbarspermidine derivatives broadened the comprehensiveness of ***,the weak response signals were captured by data-dependent scanning(DDA)followed by parallel reaction monitoring(PRM),and the efficiency of acquiring MS2 fragment ions of target compounds was significantly *** on the integrated strategy above,210 lycibarbarspermidine derivatives were detected and identified from Lycii Fructus,and in particular,170 potential new compounds were structurally *** integrated strategy improved the sensitivity of detection and the coverage of low-response components,and it is expected to be a promising pipeline for discovering new compounds.

关键词： Mass spectrometric detection Weak response signals Complex matrices Novel lycibarbarspermidines

Pregnancy outcomes in ovarian tissue cryopreservation for fertility preservation: A systematic review and meta-analysis

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

中华医学杂志(英文版) 2024年第19期137卷 2372-2374页

作者： Wang Yiling zhai Qingjie Wang Zhaohua yang Xin Wang Jianliu Zhu Honglan Department of Obstetrics and Gynecology Peking University People’s Hospital Peking University Beijing China

Challenges and Suggestions of Ethical Review on Clinical Research Involving Brain-Computer Interfaces

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Medical sciences Journal 2024年第2期39卷 131-139页

作者： Xue-Qin Wang Hong-Qiang Sun Jia-Yue Si Zi-Yan Lin Xiao-Mei zhai Lin Lu Peking University Sixth Hospital Peking University Institute of Mental HealthNHC Key Laboratory of Mental Health(Peking University)National Clinical Research Center for Mental Disorders(Peking University Sixth Hospital)Chinese Academy of Medical Sciences Research Unit(No.2018RU006)Beijing 100191China Department of Psychology University of CaliforniaDavis 95616USA Department of Psychology University of TorontoToronto M5S 1A1Canada School of Population Medicine and Public Health Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China academy for Advanced Interdisciplinary Studies Peking-Tsinghua Centre for Life Sciences and Peking University-International Development Group/McGovern Institute for Brain ResearchPeking UniversityBeijing 100871China

Brain-computer interface(BCI)technology is rapidly advancing in medical research and *** an emerging biomedical engineering technology,it has garnered significant attention in the clinical research of brain disease diagnosis and treatment,neurological rehabilitation,and mental ***,BCI also raises several challenges and ethical concerns in clinical *** this article,the authors investigate and discuss three aspects of BCI in medicine and healthcare:the state of international ethical governance,multidimensional ethical challenges pertaining to BCI in clinical research,and suggestive concerns for ethical *** the great potential of frontier BCI research and development in the field of medical care,the ethical challenges induced by itself and the complexities of clinical research and brain function have put forward new special fields for ethics in *** ensure"responsible innovation"in BCI research in healthcare and medicine,the creation of an ethical global governance framework and system,along with special guidelines for cutting-edge BCI research in medicine,is suggested.

关键词： brain-computer interface clinical research bioethics ethical governance ethical review

Constraints of f(R) gravity in Palatini approach with observational Hubble data

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(Physics,Mechanics & Astronomy) 2011年第8期54卷 1378-1383页

作者： zhai ZhongXu & LIU WenBiao Department of Physics, Institute of Theoretical Physics, beijing Normal University, beijing 100875, china 1. Department of Physics Institute of Theoretical Physics Beijing Normal University Beijing 100875 China

We use the newly released observational H(z) data (OHD), the Cosmic Microwave Background (CMB) shift parameter, and the Baryon Acoustic Oscillation (BAO) measurements data to constrain cosmological parameters of f(R) gravity in Palatini formalism in which the f(R) form is defined as f(R) = R β/Rn. Under the assumption of a spatially flat FRW universe, we get the best fitting results of the free parameters (Ωm0, n). In the calculation, we marginalize the likelihood function over H0 by integrating the probability density P ∝ e-χ2/2 to obtain the best fitting results and the confidence regions in the Ωm0-n plane. The constraints results of (Ωm0, n) = (0.33, 0.41) by OHD only and (Ωm0, n) = (0.23, 0.08) by the combination of OHD+CMB+BAO both indicate that the universe goes through three last phases, i.e., radiation dominated, matter-dominated, and late time accelerated expansion without introduction of dark energy.

关键词： f(R) gravity OHD CMB BAO accelerating expansion dark energy