检索结果-南通市图书馆

A Study on Spatial Variation of Water Security Risks for the zhangjiakou Region

Journal of Resources and Ecology 2021年第1期12卷 91-98页

作者： LU Chunxia DENG ou LI Yiqiu Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China School of Geography&Environmental Sciences Guizhou Normal UniversityGuiyang 550001China

zhangjiakou region is situated in an agro-pastoral ecotone with a fragile ecosystem. While it has limited surface water resources available and serious groundwater over-exploitation, the city is located in the water conservation zone for the Beijing-Tianjin-Hebei coordinated development area, so its water security is crucial for the entire Beijing-Tianjin-Hebei region. Therefore, it is of vital significance to determine the zoning management of water resources and decision-making according to the magnitude of water resource security risks. This study built an indicator system for water security risk assessment in line with the principles of scientific validity, comparability, operability, and data availability, and this system gives weights to these indicators using the AHP approach. County-level multi-source data for the study area, based on water resource zones, were collected by using mathematical statistics and 3 S technology. With normalized data and a weighting method the water security risks were calculated. The results showed large spatial variations of water security risks in zhangjiakou on the scales of geomorphic and administrative units as well as river basins. High-risk areas are extensive in the Bashang Plateau, and extremely high risk values are found in the Baxia areas. On the watershed scale, high-risk areas are mainly distributed in the inland river basins and the Yongding River basin. The risk values of the Luanhe River, Chaobai River and Daqing River basins in the zhangjiakou region tend to decrease from north to south. For the northern and western areas of the Bashang Plateau, the factor of "vulnerability of the disaster-prone environment" contributes the most to the water security risk level. Agricultural water use constrains industrial and ecological water use, but in the context of inadequate water resource endowments, the urban population concentration and industrial development are the main causes of water shortages and water pollution so t

关键词： water security risk assessment spatial variation zhangjiakou region

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

开放改革以来我国高等教育政策价值取向演变分析

引用

高教论坛 2019年第10期 41-44,54页

作者：欧以克付倩广西民族大学

改革开放以来,我国高等教育政策在不同历史时期表现出不同的价值选择,经历了由权力规制到简政放权、由促进经济建设到正视知识本体、由关注效率增长到重视效益优化、由培养精英到普惠大众的演变。纵观整个历程,高等教育政策价值取向的... 详细信息

改革开放以来,我国高等教育政策在不同历史时期表现出不同的价值选择,经历了由权力规制到简政放权、由促进经济建设到正视知识本体、由关注效率增长到重视效益优化、由培养精英到普惠大众的演变。纵观整个历程,高等教育政策价值取向的变化呈现出三个特点:从注重外在价值到内在价值、从单一性价值取向到多元化价值取向、从重视形式价值到实现形式价值和实质价值的有机统一。无论是何种转向,我国高等教育政策价值取向始终坚持实现国家利益和教育发展的共赢、坚持合目的性和合规律性的统一,这是国家、教育以及个体得到全面、自由、和谐发展的坚强保障。

关键词：改革开放高等教育政策价值取向演变

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

由超拍电子伏特加速器产生的超高能伽马射线气泡

引用

Science Bulletin 2024年第4期69卷 449-457页

作者： LHAASO Collaboration zhen Cao Chuandong Gao Cong Li Ruo-Yu Liu Ruizhi Yang 不详 Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China TIANFU Cosmic Ray Research Center ChengduChina Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China University of Science and Technology of China Hefei 230026China

We report the detection of aγ-ray bubble spanning at least 100deg2 in ultra-high energy(UHE)up to a few PeV in the direction of the star-forming region Cygnus X,implying the presence super PeVatron(s)accelerating protons to at least 10 PeV.A log-parabola form with the photon indexΓ(E)=(2.71±0.02)+(0.11±0.02)×log10(E/10 TeV)is found fitting the gamma-ray energy spectrum of the bubble *** sources,“hot spots”correlated with very massive molecular clouds,and a quasi-spherical amorphousγ-ray emitter with a sharp central brightening are observed in the *** the core of~0.5°,spatially associating with a region containing massive OB association(Cygnus OB2)and a microquasar(Cygnus X-3),as well as previously reported multi-TeV sources,an enhanced concentration of UHEγ-rays is observed with 2 photons at energies above 1 *** general feature of the bubble,the morphology,and the energy spectrum,are reasonably reproduced by the assumption of a particle accelerator in the core,continuously injecting protons into the ambient medium.

关键词： Cosmic rays γ-rays Interstellar medium Star cluster

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

2009—2018年广西公立医疗机构放射作业人员职业健康检查结果分析

引用

广西医学 2024年第8期46卷 1236-1241页

作者：黄雪雁陆华媛欧军荣卢小燕广西壮族自治区职业病防治研究院广西南宁市530021

目的分析2009—2018年广西壮族自治区(以下简称广西)公立医疗机构放射作业人员职业健康检查情况,为制订相应的职业健康管理措施及职业健康防护提供依据。方法收集2009—2018年9259名广西公立医疗机构放射作业人员的职业健康检查结果,比... 详细信息

目的分析2009—2018年广西壮族自治区(以下简称广西)公立医疗机构放射作业人员职业健康检查情况,为制订相应的职业健康管理措施及职业健康防护提供依据。方法收集2009—2018年9259名广西公立医疗机构放射作业人员的职业健康检查结果,比较不同性别、年龄、工龄、工种的放射作业人员各项体检结果情况。结果广西公立医疗机构放射作业人员职业健康检查中腹部B超异常、晶状体混浊、尿常规异常发生率较高;男性放射作业人员的血压异常率、肝功能异常率、腹部B超异常率、肾功能异常率高于女性,血常规异常率、尿常规异常率、甲状腺异常率低于女性(P<0.05);不同年龄放射作业人员的血压异常率、晶状体混浊率、染色体畸变率、肝功能异常率、腹部B超异常率、肾功能异常率差异有统计学意义(P<0.05),不同工龄放射作业人员的血压异常率、晶状体混浊、染色体畸变率、肝功能异常率、腹部B超异常率、尿常规异常率、肾功能异常率、甲状腺异常率差异有统计学意义(P<0.05),其中,血压异常率、晶状体混浊率、腹部B超异常率随着年龄、工龄的增加而增加;不同工种放射作业人员晶状体混浊率、腹部B超异常率、尿常规异常率、甲状腺异常率差异有统计学意义(P<0.05)。结论广西地区公立医疗机构放射作业人员健康检查结果中男性多项指标的异常率高于女性,血压异常率、晶状体混浊率、腹部B超异常率随着年龄、工龄的增加而呈上升趋势。相关部门应对不同工种人员进行有针对性的防护意识培训及作业风险评估,切实保护放射工作人员的职业健康。

关键词：职业健康公立医疗机构放射作业人员广西壮族自治区

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

Fast increasing of surface ozone concentrations in Pearl River Delta characterized by a regional air quality monitoring network during 2006–2011

引用

Journal of Environmental Sciences 2014年第1期26卷 23-36页

作者： Jinfeng Li Keding Lu Wei Lv Jun Li Liuju zhong Yubo ou Duohong Chen Xin Huang Yuanhang zhang College of Environmental Sciences Engineering Peking University Guangdong Provincial Environmental Monitoring Center

Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone （O3）, NO2 and total oxidant （Ox） were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations （non-urban） and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime （13%/yr referred to 2006 level） was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds （VOC）-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.

关键词： O3 cluster analysis temporal variation smog production algorithm Pearl River Delta

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

Highly selective metal recovery from spent lithium-ion batteries through stoichiometric hydrogen ion replacement

引用

Frontiers of Chemical Science and Engineering 2021年第5期15卷 1243-1256页

作者： Weiguang Lv Xiaohong zheng Li Li Hongbin Cao Yi zhang Renjie Chen Hancheng ou Fei Kang zhi Sun National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process EngineeringInnovation Academy for Green ManufactureChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100190China School of Materials Science&Engineering Beijing Institute of TechnologyBeijing100081China Ganz.ou Highpower Technology Co. Ltd.Ganzhou341000China

Spent lithium-ion battery recycling has attracted significant attention because of its importance in regard to the environment and resource *** hydrometallurgical methods usually leach all valuable metals and subsequently extract target meals to prepare corresponding ***,Li recovery in these processes requires lengthy operational procedures,and the recovery efficiency is *** this research,we demonstrate a method to selectively recover lithium before the leaching of other elements by introducing a hydrothermal *** 90%of Li is leached from high-Ni layered oxide cathode powders,while consuming a nearly stoichiometric amount of hydrogen *** this selective recovery of Li,the transition metals remain as solid residue hydroxides or ***,the extraction of Li is found to be highly dependent on the content of transition metals in the cathode materials.A high leaching selectivity of Li(>98%)and nearly 95%leaching efficiency of Li can be reached with LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2).In this case,both the energy and material consumption during the proposed Li recovery is significantly decreased compared to traditional methods;furthermore,the proposed method makes full use of H+to leach Li+.This research is expected to provide new understanding for selectively recovering metal from secondary resources.

关键词： recycling spent LIBs selective recovery hydrothermal treatment

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

Synthesis and Crystal Structure of a Two-dimensional Cadmium(Ⅱ) Coordination Polymer:[Cd(AIP)(Bpy)]_n·nBpy(H_2AIP=5-Aminoisophthalic Acid, Bpy=2,2′-Bipyridyl)

引用

Chinese Journal of Structural Chemistry 2008年第2期27卷 159-162页

作者： ou Yang-Jun MA Cheng-Bing CHEN Hui WANG Hui-Sheng CHEN Chang-Neng LIU Qiu-Tian State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

A two-dimensional coordination polymer, [Cd（AIP）（Bpy）]***, was hydrothermally synthesized by the reaction of hydrate cadmium acetate with 5-aminoisophthalic acid, lithium hydroxide, vanadiumpentoxide, sodium chloride and 2,2′-bipyridyl in water solution. It crystallizes in orthorhombic, space group C222 1, absolute structure parameter 0.00（7）, with a = 15.336（4）, b = 22.390（6）, c = 14.257（3）A, V = 4896（2）/~3, C28H21CdNsO4, Mr = 603.90, z = 8, F（000） = 2432, Dc = 1.639 g/cm^3, μ = 0.939 mm^-1, T= 298（2） K, S = 1.001, R = 0.0296 and wR = 0.0813 for 5522 observed reflections （I 〉 2a（/））. In the title complex, each 5-aminoisophthalate ligand bridges three cadmium（Ⅱ） ions to form a two-dimensional layer structure.

关键词： synthesis crystal structure cadmium complex 5-aminoisophthalic acid

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

Two Virus-like Particles that Cause Lytic Infections in Freshwater Cyanobacteria

引用

Virologica Sinica 2013年第5期28卷 303-305页

作者： Sanhua Li Tong ou Qiya zhang State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of Sciences

Dear Editor,We report the results of the preliminary isolation of two virus-like particles(VLPs)that are infectious to freshwater cyanobacteria from Lake Donghu,the largest urban lake in China,located in Wuhan City,Hu... 详细信息

关键词：病毒样颗粒水华蓝藻淡水感染裂解透射电子显微镜铜绿微囊藻城市湖泊

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

野外模拟降雨条件下高寒草甸区植被退化和人工植被恢复坡面的产流产沙过程

引用

水土保持学报 2024年第4期38卷 153-161页

作者：甄子雲赵洋姜群鸥解晨赵伟航刘兰华周铁军何财松周扬北京林业大学水土保持学院北京100083 北京林业大学水土保持与荒漠化防治教育部重点实验室北京100083 西藏农牧学院资源与环境学院拉萨860000 中国铁道科学研究院集团有限公司节能环保劳卫研究所北京100081

[目的]青藏高原是我国重要生态屏障,高寒草甸是其重要组成部分,水土保持功能是高寒草甸重要生态服务功能。开展青藏高原高寒草甸区水土流失过程研究对减少人为扰动水土流失、保障西南地区生态安全具有重要意义。[方法]选取青藏高原高寒... 详细信息

[目的]青藏高原是我国重要生态屏障,高寒草甸是其重要组成部分,水土保持功能是高寒草甸重要生态服务功能。开展青藏高原高寒草甸区水土流失过程研究对减少人为扰动水土流失、保障西南地区生态安全具有重要意义。[方法]选取青藏高原高寒草甸未退化、轻度退化、中度退化、裸坡与人工植被恢复5种不同类型坡面,通过野外模拟降雨试验,分析不同雨强条件下,不同植被退化与恢复坡面产流产沙过程,揭示植被退化与人工植被恢复坡面土壤侵蚀机理与水沙关系。[结果](1)高寒草甸未退化坡面与人工植草恢复坡面因其根系较为致密,其水分下渗能力相对较弱,故初始产流时间相对较短;而对于轻度退化坡面,侧流与纵向入渗能力相对较强,初始产流时间相对较长。(2)在常规降雨条件下(30,60 mm/h),轻度退化坡面产流量最小,减流效益最高,达到77.13%;人工恢复坡面产流量与未退化坡面接近,略高于轻度退化坡面;而裸土坡面累计产流量最大,且显著高于其他坡面;极端降雨条件下(90 mm/h)未退化坡面产流量激增,仅低于裸坡并明显高于人工植被恢复坡面。(3)在常规降雨条件下(30,60 mm/h),人工恢复植被坡面减沙效益最高,分别达到81.97%和89.82%,其次是未退化坡面,且随着植被退化程度增大,减沙效益逐渐降低;但在极端降雨条件下,人工恢复植被和未退化坡面减沙效益几乎相同,而中度退化坡面产沙量是未退化坡面的4.59倍;轻度退化坡面虽然具有较好的减流效益,但是减沙效益相对较差。[结论]研究结果可为高寒草甸区植被恢复与生态安全提供重要科学依据。

关键词：高寒草甸退化草甸水土流失减流减沙效益

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Activation of the p62-Keapl-NRF2 Pathway Protects against Ferroptosis in Hepatocellular Carcinoma Cells

Activation of the p62-Keapl-NRF2 Pathway Protects against Fe...

引用

第十四次全国医学遗传学学术会议

作者： Sun X ou z Chen R Niu X Chen Kang R Tang D Center for DAMP Biology The Third Affiliated Hospital of Guangzhou Medical University Department of Surgery University of Pittsburgh Cancer InstituteUniversity of Pittsburgh

Ferroptosis is a recently-recognized form of regulated cell death caused by an iron-dependent accumulation of lipid reactive oxygen ***,the molecular mechanisms regulating ferroptosis remain ***,we report that nuclear factor erythroid 2-related factor(NRF2)plays a central role in protecting hepatocellular carcinoma(HCC)cells against *** exposure to ferroptosis-inducing compounds(e.g.,erastin,sorafenib,and buthionine sulfoximine),pexpression prevented NRF2 degradation and enhanced subsequent NRF2 nuclear accumulation through inactivation of Kelch-like ECH-associated protein ***,nuclear NRF2interacted with the transcriptional coactivator small v-maf avian muscu’loaponeurotic fibrosarcoma oncogene homolog(Maf)proteins such as MafG and then activated transcription of quinone oxidoreductase 1(NQO1),heme oxygenase-1(HO1),and ferritin heavy chain 1(FTH1).Knockdown of p62,NQO1,HO1,and FTH1 by RNAi in HCC cells promoted ferroptosis in response to erastin and ***,genetic or pharmacologic inhibition of NRF2 expression/activity in HCC cells increased the anticancer activity of erastin and sorafenib in vitro and in tumor xenograft ***:These findings demonstrate novel molecular mechanisms and signaling pathways of *** status of NRF2 is a key factor that determines the therapeutic response to ferroptosis-targeted therapies in HCC cells.

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

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：