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Mapping upland crop–rice cropping systems for targeted sustainable intensification in South China
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作者 Bingwen Qiu Linhai Yu +4 位作者 Peng Yang wenbin wu Jianfeng Chen Xiaolin Zhu Mingjie Duan 《The Crop Journal》 SCIE CSCD 2024年第2期614-629,共16页
Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural intensification.Accurate UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural revitalization.Howeve... Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural intensification.Accurate UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural revitalization.However,datasets describing cropping systems are limited in spatial coverage and crop types.Mapping UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples,which limits its applications over large regions.We describe a novel algorithm(RRSS)for automatic mapping of upland crop-rice cropping systems using Sentinel-1 Synthetic Aperture Radar(SAR)and Sentinel-2 Multispectral Instrument(MSI)data.One indicator,the VV backscatter range,was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed UCR.The RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic conditions.This study developed 10-m UCR maps of a major rice bowl in South China,the Xiang-Gan-Min(XGM)region.The performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites,with an overall accuracy of 91.92%.There were7348 km^(2) areas of UCR,roughly one-half of them located in plains.The UCR was represented mainly by oilseed-UCR and tobacco-UCR,which contributed respectively 69%and 15%of UCR area.UCR patterns accounted for only one-tenth of rice production,which can be tripled by intensification from single rice cropping.Application to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm,which could be further applied to generate 10-m UCR datasets for application at national or global scales. 展开更多
关键词 Cropping-pattern mapping Paddy rice Sentinel-1/2 China Sustainable intensification
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Inner Cascaded U^(2)-Net:An Improvement to Plain Cascaded U-Net
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作者 wenbin wu Guanjun Liu +1 位作者 Kaiyi Liang Hui Zhou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期1323-1335,共13页
Deep neural networks are now widely used in the medical image segmentation field for their performance superiority and no need of manual feature extraction.U-Net has been the baseline model since the very beginning du... Deep neural networks are now widely used in the medical image segmentation field for their performance superiority and no need of manual feature extraction.U-Net has been the baseline model since the very beginning due to a symmetricalU-structure for better feature extraction and fusing and suitable for small datasets.To enhance the segmentation performance of U-Net,cascaded U-Net proposes to put two U-Nets successively to segment targets from coarse to fine.However,the plain cascaded U-Net faces the problem of too less between connections so the contextual information learned by the former U-Net cannot be fully used by the latter one.In this article,we devise novel Inner Cascaded U-Net and Inner Cascaded U^(2)-Net as improvements to plain cascaded U-Net for medical image segmentation.The proposed Inner Cascaded U-Net adds inner nested connections between two U-Nets to share more contextual information.To further boost segmentation performance,we propose Inner Cascaded U^(2)-Net,which applies residual U-block to capture more global contextual information from different scales.The proposed models can be trained from scratch in an end-to-end fashion and have been evaluated on Multimodal Brain Tumor Segmentation Challenge(BraTS)2013 and ISBI Liver Tumor Segmentation Challenge(LiTS)dataset in comparison to related U-Net,cascaded U-Net,U-Net++,U^(2)-Net and state-of-the-art methods.Our experiments demonstrate that our proposed Inner Cascaded U-Net and Inner Cascaded U^(2)-Net achieve better segmentation performance in terms of dice similarity coefficient and hausdorff distance as well as get finer outline segmentation. 展开更多
关键词 Deep neural networks medical image segmentation U-Net cascaded convolution block
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天空地数字农业管理系统框架设计与构建建议 被引量:23
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作者 吴文斌 史云 +6 位作者 周清波 杨鹏 刘海启 王飞 刘佳 王利民 张保辉 《智慧农业》 2019年第2期64-72,共9页
数据正在成为基础性战略资源。构建以天空地大数据为关键要素的数字农业管理系统,对于建设数字中国、推进农业高质量发展、抢占全球农业制高点具有重要意义。本研究围绕农业农村部提出的天空地数字农业管理系统建设任务,从农业信息技术... 数据正在成为基础性战略资源。构建以天空地大数据为关键要素的数字农业管理系统,对于建设数字中国、推进农业高质量发展、抢占全球农业制高点具有重要意义。本研究围绕农业农村部提出的天空地数字农业管理系统建设任务,从农业信息技术学科出发,首先给出了天空地数字农业的科学内涵,阐述了其与传统数字农业的异同点,理清了天空地数字农业管理系统在资源调查、生产调度、灾害监测、市场预警、决策服务的五大核心功能;其次,重点阐述了天空地数字农业管理系统的关键任务,即一个观测体系(天空地一体化的数字农业观测体系)、四个数字化(农业资源权属、生产过程、灾害监测和市场预警)、一个管理平台(农业生产、加工、经营、管理、服务等全产业链的天空地数字农业管理平台);然后,明确提出了天空地数字农业管理系统在标准规范研制、关键技术与装备研发、系统集成与平台开发三方面的科技创新重点任务;最后,针对天空地数字农业管理系统建设的复杂性和系统性,从规划设计、科技创新、资源共享、多方参与、应用领域拓展等方面提出了发展建议。 展开更多
关键词 天空地一体化 数字农业 管理系统 监测 预警 决策
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Ethylene Emission as a Potential Indicator of Fuji Apple Flavor Quality Evaluation Under Low Temperature 被引量:19
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作者 Weiyan Qi Haijing Wang +4 位作者 Zhen Zhou Peng Yang wenbin wu Zhemin Li Xian Li 《Horticultural Plant Journal》 SCIE 2020年第4期231-239,共9页
Fuji apple(Malus×domestica Borkh.)is a popular fruit cultivar and occupies an important position in the fruit market due to its excellent flavor and storage quality.Ethylene emission can induce respiration,which ... Fuji apple(Malus×domestica Borkh.)is a popular fruit cultivar and occupies an important position in the fruit market due to its excellent flavor and storage quality.Ethylene emission can induce respiration,which would reduce postharvest quality and increase storage losses.In order to maintain fruit quality and extend shelf life,apples are usually stored in a low-temperature environment after harvest to reduce the formation of ethylene.Volatile aroma components are regarded as one of the most important aspects of flavor quality and a key factor for apple quality grading and customer satisfaction.Ethylene emission and its relationship with volatile aromas during low temperature,however,have not been determined.In this study,the dynamic changes of volatile aroma compounds of Fuji apples stored at 4°C were detected and analyzed for 42 days.The variation of ethylene released from Fuji apple was studied correspondingly.The results showed that ethyl butyrate,ethyl caproate,ethyl 2-methylbutyrate and 2-methylbutyl acetate were the main aroma components of Fuji apple.The change in ethylene emission and the normalized peak area of volatile aroma compounds exhibited a similar tendency that increased significantly from the 3rd day to the peak on the 14th day and then decreased;there was a positive linear correlation between them with a correlation coefficient of 0.79(P<0.05).Therefore,ethylene release can be used as a potential indicator for evaluation of volatile aroma compounds in apples.Using ethylene emission as an indicator could reduce the difficulty and complexity of volatile aroma evaluation,which could be a new non-destructive inspection choice for apple flavor quality assessment. 展开更多
关键词 APPLE AROMA flavor quality ETHYLENE correlation analysis
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Studies on the Degranulation of RBL-2H3 Cells Induced by Traditional Chinese Medicine Injections 被引量:2
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作者 Jia-Ming Tang Jiong Liu wenbin wu 《Chinese Medicine》 2012年第4期200-208,共9页
Aims: To study RBL-2H3 cell degranulation phenomena induced by some TCMIs through cell morphological and ultra-structural observation, released enzyme activity and establish RBL-2H3 cell degranulation test indicated ... Aims: To study RBL-2H3 cell degranulation phenomena induced by some TCMIs through cell morphological and ultra-structural observation, released enzyme activity and establish RBL-2H3 cell degranulation test indicated by β- hexosaminidase activity as a method to evaluate TCMIs at nonclinical stage. Methods: RBL-2H3 cells were used to study the degranulation by co-culture with positive control C48/80 and some TCMIs through morphological and ultra-structure observation, β-hexosaminidase activity detection. RBL-2H3 cell degranulation test was established to detect β-hexosaminidase activity caused by 17 kinds of TCMIs and their ingredients. The cytotoxicity effect of some TCMIs on both RBL 2H3 and BRL cells was measured by CCK-8 assay. Results: Toluidine blue staining and ultra-structure of electronic microscope observation of treated RBL-2H3 cells showed degranulation morphologically. Detection of β-hexosaminidase activity in the supernatant of treated cells showed some TCMIs had elevated enzyme release rates. Further analysis of the ingredients and compound in Tanreqing Injection and Shengmai Injection showed Scutellaria baicalensis Georgi in Tanreqing Injection, Red ginseng and Fructus Schisandrae Chinensis in Shengmai Injection were responsible to the degranulation of RBL-2H3 cells. Osmotic pressures and pH influenced RBL-2H3 degranulation. High Osmotic pressure of Tanreqing Injection and low pH of chlorogenic acid at 2.5 and 5.0 mmol/L congcentration might be responsible to high β-hexosaminidase activity. Most of the TCMIs inducing degranulation had cytotoxicity effect for both RBL-2H3 and BRL cells, but some TCMIs inducing degranulation had no cytotoxicity effect. Conclusion: Some TCMIs can induce degranulation of RBL-2H3 cells;RBL-2H3 cell degranulation test can be used in non-clinical stage to detect the risk causing anaphylactoid reactions. Osmotic pressures and pH influenced RBL-2H3 degranulation, and they should be measured before testing. The mechanism of degranulation caused by some TCMIs is cytotoxic, and some are non-cytotoxic and may be through exicytosis. 展开更多
关键词 TRADITIONAL Chinese MEDICINE INJECTION (TCMI) RBL-2H3 Cells DEGRANULATION β-Hexosaminidase Anaphylactoid Reaction
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Integrated data analysis on the electron temperature profile of HL-2A with the Bayesian probability inference method
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作者 潘文安 王天博 +10 位作者 王志斌 杨勇濠 吴豪 Geert VERDOOLAEGE 杨曾辰 刘春华 郭文平 李兵利 刘自结 吴文斌 许敏 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第5期237-252,共16页
Data analysis on tokamak plasmas is mainly based on various diagnostic systems,which are usually modularized and independent of each other.This leads to a large amount of data not being fully and effectively exploited... Data analysis on tokamak plasmas is mainly based on various diagnostic systems,which are usually modularized and independent of each other.This leads to a large amount of data not being fully and effectively exploited so that it is not conducive to revealing the deep physical mechanism.In this work,Bayesian probability inference with machine learning methods have been applied to the electron cyclotron emission and Thomson scattering diagnostic systems on HL-2A/2M,and the effects of integrated data analysis(IDA)on the electron temperature of HL-2A with Bayesian probability inference are demonstrated.A program is developed to infer the whole electron temperature profile with a confidence interval,and the program can be applied in online analysis.The IDA results show that the full profile of the electron temperature can be obtained and the diagnostic information is more comprehensive and abundant with IDA.The inference models for electron temperature analysis are established and the developed programs will serve as an experimental data analysis tool for HL-2A/2M in the near future. 展开更多
关键词 electron cyclotron emission Thomson scattering electron temperature Bayesian inference
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A combined nanotherapeutic approach targeting farnesoid X receptor,ferroptosis,and fibrosis for nonalcoholic steatohepatitis treatment
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作者 Jiangtao Fu Pingping Zhang +10 位作者 Zhiguo Sun Guodong Lu Qi Cao Yiting Chen wenbin wu Jiabao Zhang Chunlin Zhuang Chunquan Sheng Jiajun Xu Ying Lu Pei Wang 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2024年第5期2228-2246,共19页
Obeticholic acid(OCA),a farnesoid X receptor(FXR)agonist with favorable effects on fatty and glucose metabolism,has been considered the leading candidate drug for nonalcoholic steatohepatitis(NASH)treatment.However,it... Obeticholic acid(OCA),a farnesoid X receptor(FXR)agonist with favorable effects on fatty and glucose metabolism,has been considered the leading candidate drug for nonalcoholic steatohepatitis(NASH)treatment.However,its limited effectiveness in resolving liver fibrosis and lipotoxicity-induced cell death remains a major drawback.Ferroptosis,a newly recognized form of cell death characterized by uncontrolled lipid peroxidation,is involved in the progression of NASH.Nitric oxide(NO)is a versatile biological molecule that can degrade extracellular matrix.In this study,we developed a PEGylated thiolated hollow mesoporous silica nanoparticles(MSN)loaded with OCA,as well as a ferroptosis inhibitor liproxsatin-1 and a NO donor S-nitrosothiol(ONL@MSN).Biochemical analyses,histology,multiplexed flow cytometry,bulk-tissue RNA sequencing,and fecal 16S ribosomal RNA sequencing were utilized to evaluate the effects of the combined nanoparticle(ONL@MSN)in a mouse NASH model.Compared with the OCA-loaded nanoparticles(O@MSN),ONL@MSN not only protected against hepatic steatosis but also greatly ameliorated fibrosis and ferroptosis.ONL@MSN also displayed enhanced therapeutic actions on the maintenance of intrahepatic macrophages/monocytes homeostasis,inhibition of immune response/lipid peroxidation,and correction of microbiota dysbiosis.These findings present a promising synergistic nanotherapeutic strategy for the treatment of NASH by simultaneously targeting FXR,ferroptosis,and fibrosis. 展开更多
关键词 Nonalcoholic steatohepatitis Nanotherapy Farnesoid X receptor Ferroptosis FIBROSIS Obeticholic acid S-NITROSOTHIOL Liproxstatin-1
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Absence of metallicity and bias-dependent resistivity in low-carrier-density EuCd_(2)As_(2)
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作者 Yuxiang Wang Jianwen Ma +10 位作者 Jian Yuan wenbin wu Yong Zhang Yicheng Mou Jiaming Gu Peihong Cheng wu Shi Xiang Yuan Jinglei Zhang Yanfeng Guo Cheng Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2024年第4期119-125,共7页
EuCd_(2)As_(2)was theoretically predicted to be a minimal model of Weyl semimetals with a single pair of Weyl points in the ferromagnet state.However,the heavily p-doped Eu Cd_(2)As_(2)crystals in previous experiments... EuCd_(2)As_(2)was theoretically predicted to be a minimal model of Weyl semimetals with a single pair of Weyl points in the ferromagnet state.However,the heavily p-doped Eu Cd_(2)As_(2)crystals in previous experiments prevent direct identification of the semimetal hypothesis.Here,we present a comprehensive magneto-transport study of high-quality Eu Cd_(2)As_(2)crystals with ultralow bulk carrier density(10^(13)cm^(-3)).In contrast to the general expectation of a Weyl semimetal phase,Eu Cd_(2)As_(2)shows insulating behavior in both antiferromagnetic and ferromagnetic states as well as surface-dominated conduction from band bending.Moreover,the application of a dc bias current can dramatically modulate the resistance by over one order of magnitude,and induce a periodic resistance oscillation due to the geometric resonance.Such nonlinear transport results from the high nonequilibrium state induced by an electrical field near the band edge.Our results suggest an insulating phase in Eu Cd_(2)As_(2)and put a strong constraint on the underlying mechanism of anomalous transport properties in this system. 展开更多
关键词 magnetic Weyl semimetal quantum transport Hall effect nonlinear resistivity
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真实土地覆被变化的局地温度效应呈现出显著的纬度差异和不对称性
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作者 刘向阳 李召良 +12 位作者 李弈韬 吴骅 周成虎 司梦林 冷佩 段四波 杨鹏 吴文斌 唐荣林 刘萌 尚国琲 张霞 高懋芳 《Science Bulletin》 SCIE EI CAS CSCD 2023年第22期2849-2861,M0006,共14页
局地温度对土地覆被变化(Land cover change,LCC)的生物物理响应是目前研究的热点问题.以往基于观测的工作主要使用空间代替时间的假设分析潜在影响,并聚焦于毁林/造林活动,而实际发生的所有类型的LCC对温度的真实影响仍未被充分探索.... 局地温度对土地覆被变化(Land cover change,LCC)的生物物理响应是目前研究的热点问题.以往基于观测的工作主要使用空间代替时间的假设分析潜在影响,并聚焦于毁林/造林活动,而实际发生的所有类型的LCC对温度的真实影响仍未被充分探索.本研究采用空间结合时间的策略,同时利用海量1 km分辨率的卫星观测,实现了这一评估.结果表明,2006~2015年,全球发生LCC的区域平均温度增加0.08 K,但在不同纬度呈现显著差异,温度变化从-0.05 K到0.18 K;耕地扩张主导了北半球中纬度地区夏季的降温作用,而森林相关变化造成了其他区域的升温作用;这些温度效应占同期整体升温的比值最高可达44.6%,表明LCC对局地温度的影响不可忽略.另外,真实影响存在明显的不对称性特征:产生增温效应的LCC比降温效应的LCC具有更大的发生面积和作用强度,即使是在相同区域两种覆被类型之间的相互转换,增温LCC通常也具有比其反转的降温LCC更大的作用强度,这是由转换程度和驱动变量的不对称变化共同造成.这些新的发现来源于对真实发生LCC的估算,因此可为土地管理和气候缓解政策提供更现实的指导. 展开更多
关键词 Land cover change Land surface temperature Biophysical process Observation-based
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温度场下岛-桥结构屈曲薄膜的动力学分析 被引量:1
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作者 吴文斌 王博 +2 位作者 王振洋 周煜棠 邓子辰 《固体力学学报》 CAS CSCD 北大核心 2021年第5期543-551,共9页
基于岛-桥结构的柔性电子器件已被用于健康监测和皮肤电子等领域.但是柔性电子器件在工作中极易受工作温度变化等激励产生振动,进而影响器件的灵敏度与可靠性.因此论文研究在温度场作用下岛-桥结构屈曲薄膜的动力学问题.首先,基于Euler-... 基于岛-桥结构的柔性电子器件已被用于健康监测和皮肤电子等领域.但是柔性电子器件在工作中极易受工作温度变化等激励产生振动,进而影响器件的灵敏度与可靠性.因此论文研究在温度场作用下岛-桥结构屈曲薄膜的动力学问题.首先,基于Euler-Bernoulli梁理论,建立温度场作用下岛-桥结构屈曲薄膜的动力学控制方程.其次,通过引入新变量,将原动力学方程引入Hamilton体系中,得到相应的Hamilton正则方程.随后,采用辛Runge-Kutta方法求解该Hamilton正则方程,并与经典Runge-Kutta方法对比,数值结果显示了辛算法在求解非线性动力学方程时高精度、高数值稳定性的优势,进一步讨论了温度变化量、预应变、阻尼系数等对屈曲薄膜动力学响应的影响.论文研究为柔性电子器件动力学设计提供了理论参考. 展开更多
关键词 柔性电子 薄膜 温度影响 辛Runge-Kutta方法 动态屈曲
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Asymmetric interfaces and high-TC ferromagnetic phase in La_(0.67)Ca_(0.33)MnO_(3)/SrRuO_(3)superlattices 被引量:1
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作者 Lili Qu Da Lan +14 位作者 Liang Si Chao Ma Shasha Wang Liqiang Xu Kexuan Zhang Feng Jin Zixun Zhang Enda Hua Binbin Chen Guanyin Gao Feng Chen Haifeng Du Karsten Held Lingfei Wang wenbin wu 《Nano Research》 SCIE EI CSCD 2021年第10期3621-3628,共8页
Interfacial magnetism in functional oxide heterostructures not only exhibits intriguing physical phenomena but also implies great potential for device applications.In these systems,interfacial structural and electroni... Interfacial magnetism in functional oxide heterostructures not only exhibits intriguing physical phenomena but also implies great potential for device applications.In these systems,interfacial structural and electronic reconstructions are essential for improving the stability and tunability of the magnetic properties.In this work,we constructed ultra-thinLa_(0.67)Ca_(0.33)MnO_(3)/SrRuO_(3)(SRO)layers into superlattices,which exhibited a robust ferromagnetic phase.The high Curie temperature(TC)reaches 291 K,more than 30 K higher than that of bulk LCMO.We found that the LCMO/SRO superlattices consisted of atomically-sharp and asymmetric heterointerfaces.Such a unique interface structure can trigger a sizable charge transfer as well as a ferroelectric-like polar distortion.These two interfacial effects cooperatively stabilized the high-T_(C)ferromagnetic phase.Our results could pave a promising approach towards effective control of interfacial magnetism and new designs of oxide-based spintronic devices. 展开更多
关键词 oxide heterointerfaces asymmetric interfacial effects ferromagnetic order charge transfer
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The TripleSat constellation:a new geospatial data service model 被引量:1
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作者 Qiang Wen Jianjun He +7 位作者 Shengyong Guan Ting Chen Yin Hu wenbin wu Feng Liu Yuexia Qiao Suet Yheng Kok Samuel Yeong 《Geo-Spatial Information Science》 SCIE EI CSCD 2017年第2期163-173,共11页
With the increase of different sensors,applications and customers,the demand from data providers and users is for a new geospatial data service model,which supports low cost,high dexterity,and which would provide a co... With the increase of different sensors,applications and customers,the demand from data providers and users is for a new geospatial data service model,which supports low cost,high dexterity,and which would provide a comprehensive service.Based on such requirements and demands,the 21AT TripleSat constellation terminal and data delivery and management system has been developed by a Beijing based high-tech enterprise,Twenty First Century Aerospace Technology Co.,Ltd.(21AT).The company is the first commercial Earth observation satellite operator and service provider in China.This new geospatial data service model allows the user to directly access multi-source satellite data,manage the data order,and carry out automatic massive data production and delivery.The solution also implements safe and hierarchical user management,statistical data analysis,and automatic information reports.In addition,a mobile application is also available for users to easily access system functions.This new geospatial solution has already been successfully applied and installed in many customer sites in China,and is now available globally for international clients interested in fast geospatial solutions.It enables the success of customers’operational services.Besides providing TripleSat Constellation images,the multi-source data access system also allows the users to access other satellite data sources,based on customized agreement.This paper describes and discusses this new geospatial data service model. 展开更多
关键词 Geospatial data service model 21AT TripleSat constellation geospatial instant service system
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Multiple charge ion beam generation with a 2.45 GHz electron cyclotron resonance ion source
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作者 Yuan Xu ShiXiang Peng +7 位作者 HaiTao Ren JiaMei Wen AiLin Zhang Tao Zhang JingFeng Zhang wenbin wu ZhiYu Guo JiaEr Chen 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第6期74-77,共4页
Multiple charge ions (MCIs) are necessary for increasing the output energy of particles in accelerators. In general, MCI beams are largely produced by electron beam ion source (EBIS) [1], laser ion source (LIS) [2], o... Multiple charge ions (MCIs) are necessary for increasing the output energy of particles in accelerators. In general, MCI beams are largely produced by electron beam ion source (EBIS) [1], laser ion source (LIS) [2], or high-frequency (mostly >5 GHz) electron cyclotron resonance (ECR) ion source [3]. Among these, only ECR ion source can operate in the continuous wave (CW) mode, while EBIS and LIS only support pulses. In addition, ECR ion source with lower frequency (mostly 2.45 GHz) are required primarily for generating single charge state ions, because the corresponding ECR field (875 Gs) is not sufficiently strong for MCI generation [4]. 展开更多
关键词 电子回旋共振离子源 多电荷离子 离子束 GHZ ECR离子源 MCIS 电子束离子源 激光离子源
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Plasma parameter diagnosis using hydrogen emission spectra of a quartz-chamber 2.45 GHz ECRIS at Peking University
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作者 wenbin wu HaiTao Ren +8 位作者 ShiXiang Peng Yuan Xu JiaMei Wen Tao Zhang JingFeng Zhang AiLin Zhang Jiang Sun ZhiYu Guo JiaEr Chen 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第4期69-74,共6页
A quartz-chamber 2.45 GHz electron cyclotron resonance ion source(ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 m A hydro... A quartz-chamber 2.45 GHz electron cyclotron resonance ion source(ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 m A hydrogen ion beam at 50 k V with a duty factor of 10%. The root-mean-square(RMS) emittance of this beam is less than 0.12π mm mrad. In our initial work,the electron temperature and electron density inside the plasma chamber had been measured with the line intensity ratio of noble gases. Based on these results, the atomic and molecular emission spectra of hydrogen were applied to determine the dissociation degree of hydrogen and the vibrational temperature of hydrogen molecules in the ground state, respectively. Measurements were performed at gas pressures from 4×10^(-4) to 1×10^(-3) Pa and at input peak RF power ranging from 1000 to 1800 W. The dissociation degree of hydrogen in the range of 0.5%-10% and the vibrational temperature of hydrogen molecules in the ground state in the range of 3500-8500 K were obtained. The plasma processes inside this ECRIS chamber were discussed based on these results. 展开更多
关键词 ECRIS 北京大学 氢离子 GHZ 房间 血浆 排放 诊断
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