检索结果-南通市图书馆

Stratification in central Bohai Sea and how it has shaped hypoxic events in summer

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

Acta Oceanologica Sinica 2024年第9期43卷 93-104页

作者： Jie Guo Diansheng Ji xiangyang zheng Yanfang Li Haitian Tang Chawei Hou CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China Shandong Key Laboratory of Coastal Environmental Processes Yantai 264003China Yantai Marine Center of the Ministry of Natural Resources Yantai 264006China

In the last 10 years(2012-2021),five hypoxic events have been observed in summer in the central Bohai Sea(CBS).Frequent and persistent hypoxia will have an impact on the ecosystem of the *** this paper,historical sea temperature(ST),salinity(SAL),density(Den),and dissolved oxygen(DO)concentration data from three stations in the CBS are analyzed via the linear regression method,and the correlations between the stratification factors(ST,SAL,and Den)and DO concentration are *** thresholds of the stratification factors at the three stations in June in the year in which hypoxia occurred were determined and applied to survey data from 29 stations in late May to early June in 2022 in the CBS;this assessment found that the data from 19 stations indicated that hypoxia was about to *** August,the survey data showed that 14 out of the 29 stations indicated hypoxic conditions,of which 12 were from the predicted 19 stations,meaning that the estimation accuracy reached 63%.The same approach was applied to data from June *** data for August from a bottom-type online monitoring system in the CBS verified the occurrence of hypoxic events around *** results show that the strength of the seawater stratification plays a leading role in hypoxic events in the summer in the CBS,and the thresholds of the stratification factors can be used to predict the occurrence of hypoxic events.

关键词： hypoxia central Bohai Sea sea temperature salinity sea-water density stratification

A method to estimate gas magnification of multi-gap resistive plate chamber

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2007年第5期18卷 298-301页

作者： WU Yuelei HU Huasi QIN Juan WANG Xiaolian zheng xiangyang XU Zizong Nuclear Engineering Department School of Energy and Power Engineering Xi＇ an Jiaotong University Xi＇an 710049 China Department of Modern Physics University of Science ＆ Technology of China Hefei 230026 China

The gas magnification of multi-gap resistive plate chamber (MRPC) is very difficult to be measured using the present instruments thoroughly in the world. The gas magnifications about ~107 were obtained in the various operation-high-voltages of multi-gap resistive plate chamber (MRPC) by means of Monte-Carlo simulation and the presented experiment method.

关键词：放大倍数模拟实验探测器探测方法

Optimal design of coded aperture used for Z-Pinch driven fusion neutron imaging

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第7期58卷 1289-1293页

作者： JIA QingGang HU HuaSi zheng xiangyang ZHANG FengNa WANG DongMing HU Guang ZHANG TianKui WU YueLei Institute of Nuclear Science and Technology Xi'an Jiaotong University State Environmental Protection Administration (SEPA) Nuclear and Radiation Safety Centre Research Center of Laser Fusion China Academy of Engineering Physics

Currently,the neutron yield of Z-Pinch is lower than that of laser driven *** the neutron imaging for this facility,the signal to noise ratio(SNR)has a significant influence on the expected spatial resolution of the reconstructed fusion core,especially in the condition of low neutron *** this paper,mathematical model is purposed to describe the dependence of aperture parameters on the imaging *** investigation shows that the imaging SNR is closely related to the size of contrast boundary on the point spread *** to this,a novel non-uniform redundancy penumbra apertures array is *** addition,the imaging performances of this novel coded aperture,penumbra aperture and ring aperture are evaluated and compared by Monte Carlo *** comparison shows that this novel aperture has significant advantage compared to the penumbra aperture which is commonly used for neutron imaging with low *** encouraging results can provide reference for the optimal design of the coded aperture used in the neutron imaging for Z-pinch driven fusion with low neutron yield.

关键词： Z-pinch driven fusion neutron imaging coded aperture signal to noise ratio low neutron yield

Comparative Study of Chinese and foreign independent films

在线全文

学校读者我要写书评

暂无评论

International Journal of Technology Management 2013年第4期 111-113页

作者： xiangyang zheng School of Art & Design Lanzhou Jiaotong University LanzhouGansu730070 China

The concept of ＂Independent film＂ comes from the middle of last century＇s in Hollywood. Hollywood at that time, because of the monopolization of the so-called ＂eight movie companies＂, the shooting and operation of a film followed rigorous steps of ＂producer system.＂ The target of the ＂producer system＂ entirely aimed at the market in order to get the maximum profits; therefore, although this system brought a lot of money to the film industry, it also limited the filmmakers＇ play space. Thus, a group of filmmakers got rid of the eight movie companies＇ control and made self-financing, or even wrote and direct red by themselves, they shot a lot of strong ideological films which were different with commercial films, known as the＂ Independent Film ＂.

关键词： comparative study independent films film companies.

BiVO_(4)/CoPc S型异质结的构建及其光热增强光催化性能

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 Materials 2024年第2期67卷 550-561页

作者：龙子洋郑相阳史海峰 School of Science Jiangnan UniversityWuxi 214122China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China

光热催化降解去除污染物对解决环境问题具有独特的优势.本文通过水热法结合超声处理的方法合成了BiVO4/CoPc S型异质结光热催化材料.实验结果表明,BVO-1%CoPc在10分钟内对四环素对降解率可达76%,相比钒酸铋单质提高了1.8倍.进一步的红... 详细信息

光热催化降解去除污染物对解决环境问题具有独特的优势.本文通过水热法结合超声处理的方法合成了BiVO4/CoPc S型异质结光热催化材料.实验结果表明,BVO-1%CoPc在10分钟内对四环素对降解率可达76%,相比钒酸铋单质提高了1.8倍.进一步的红外热成像仪表明酞菁钴(CoPc)的光热效应可以提高反应体系的温度.同时,研究人员还发现降解后的中间产物毒性显著降低.光致发光光谱的结果表明,合成的复合材料可以增强光生载流子的分离能力.基于捕获实验、能带结构和原位XPS等研究结果,我们提出了光生电荷在合成的催化剂中的S型传输机制.本工作为设计和开发用于去除有机污染物的S型光热催化材料提供了一种可行的策略.

关键词： BiVO_(4) CoPc photothermal effect S-scheme heterojunction tetracycline

提升农村金融体系运行效率的政策效果测度与分析

在线全文

学校读者我要写书评

暂无评论

金融理论与实践 2021年第12期 45-55页

作者：郑向阳门超中国人民银行石家庄中心支行河北石家庄050000

随着乡村振兴战略的逐步开展,满足乡村振兴战略金融需求成为金融体系的重要任务。实现相关政策体系在金融精准扶贫阶段同金融服务乡村振兴阶段的有序衔接、平稳过渡和优化调整,以打通农村金融“堵点”,提升农村金融体系运行效率至关重... 详细信息

随着乡村振兴战略的逐步开展,满足乡村振兴战略金融需求成为金融体系的重要任务。实现相关政策体系在金融精准扶贫阶段同金融服务乡村振兴阶段的有序衔接、平稳过渡和优化调整,以打通农村金融“堵点”,提升农村金融体系运行效率至关重要。基于调查数据,运用动态DEA模型对河北省农村金融体系运行效率进行测度,并构建面板模型分析各类政策工具和措施的效果,得出如下结论①:近年来农村金融体系改革发展取得了一定成效,农村金融体系运行效率呈整体上升的态势;货币政策、财政政策工具以及发展新型农村金融机构、优化农村法律环境和推动金融基础设施建设等方面的措施对提升农村金融体系运行效率具有显著作用;农信机构改革、塑造农村金融市场竞争性、融资担保体系和信用环境建设等方面的措施效果不显著。由此,在金融服务乡村振兴阶段,应确保效果显著的政策工具和措施持续发力,对效果不显著政策措施进行优化调整。

关键词：农村金融体系运行效率政策效果

同方期刊数据库

变电站三维可视化监控系统——以焦作市修武变电站为例

在线全文

学校读者我要写书评

暂无评论

科技通报 2014年第1期30卷 166-169页

作者：郑向阳魏华南焦作供电公司运维检修部河南焦作454001

运用三维可视化技术和空间技术,真实和直观地再现修武变电站的建筑、供电设备以及地表信息的三维景观,能够使用户浏览各种实体的属性信息;结合修武变电站业务生产需要,构筑一个三维可视化监控系统,实现"电力流、信息流、业务流"高度融合... 详细信息

运用三维可视化技术和空间技术,真实和直观地再现修武变电站的建筑、供电设备以及地表信息的三维景观,能够使用户浏览各种实体的属性信息;结合修武变电站业务生产需要,构筑一个三维可视化监控系统,实现"电力流、信息流、业务流"高度融合,为变电站设施设备管理、安全生产管理、应急指挥管理提供科学化、智能化的信息平台;也能够提供三维地理及信息数据,以便更加快捷、节约地进行设备的维修、更换、改造等。通过本系统可以大大减轻人工巡检的工作强度,提高工作效率,提升变电站的智能化水平。

关键词：变电站三维可视化监控

发射药颗粒间摩擦系数测定及其对装填密度的影响

在线全文

学校读者我要写书评

暂无评论

弹道学报 2019年第1期31卷 85-91页

作者：郑向阳张领科符少波南京理工大学能源与动力工程学院江苏南京210094 西安北方惠安化学工业有限公司陕西西安710300

为测量发射药颗粒间的摩擦系数并探究其对装填密度的影响,以表面涂有石墨的发射药颗粒为研究对象,采用传统的斜面仪来测量静摩擦系数;对于滚动摩擦系数的测定,基于离散单元法,模拟发射药颗粒堆积过程,得到模拟堆积角与滚动摩擦系数间的... 详细信息

为测量发射药颗粒间的摩擦系数并探究其对装填密度的影响,以表面涂有石墨的发射药颗粒为研究对象,采用传统的斜面仪来测量静摩擦系数;对于滚动摩擦系数的测定,基于离散单元法,模拟发射药颗粒堆积过程,得到模拟堆积角与滚动摩擦系数间的线性拟合方程,再基于实验所测堆积角进行参数标定获取参数值,二次拟合结果说明该参数测定方法可行。模拟结果表明,堆积角随着滚动摩擦系数的增大而增大。通过模块装填模拟,探究摩擦系数对装填密度的影响,结果表明,随着摩擦系数的增大,模块所装发射药的颗粒数越小,装填密度越小,说明摩擦系数对模块装填密度的影响是一个不可忽略的因素。

关键词：发射药摩擦系数堆积角离散单元法模拟

基于ARIMA的安全生产事故预测与实证研究

在线全文

学校读者我要写书评

暂无评论

工业安全与环保 2015年第3期41卷 78-80,102页

作者：郑向阳李正君中国石化河南油田人力资源开发中心河南南阳473132 中国石化河南油田双河社区河南南阳473132

为了减少企业安全管理者在生产作业中由于不确定性导致错误决策所产生的风险,在企业历年安全生产事故数据基础上进行预测具有一定的现实意义。以某企业2008年至2011年的安全生产事故次数时序数据,采用EViews 5统计分析软件,基于ARIMA时... 详细信息

为了减少企业安全管理者在生产作业中由于不确定性导致错误决策所产生的风险,在企业历年安全生产事故数据基础上进行预测具有一定的现实意义。以某企业2008年至2011年的安全生产事故次数时序数据,采用EViews 5统计分析软件,基于ARIMA时间序列预测模型更加关注对事故发生是否平稳而相对于其他预测模型更关注于趋势研究的良好特点,建立安全生产事故ARIMA时序预测模型,并对2012年的安全生产事故发生次数进行预测,通过效果检验发现该模型预测结果基本上能够反映该企业安全生产事故发生的实际情况。通过ARIMA方法在某企业安全生产事故预测具体案例的实现,是对现有安全生产事故预测方法的补充和完善,可为企业安全管理和决策提供一定的指导。

关键词：安全生产事故预测时间序列 ARIMA