检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

新疆伊犁出土鎏金铜带饰的科学分析与保护

文博 2019年第5期 101-107页

作者：朱思颖刘成朱奕凡西北大学文化遗产学院

为研究、保护和修复伊犁地区出土鎏金铜带饰,在现代保护修复理念的指导下,采用金相显微镜、X射线荧光、扫描电镜及X射线能谱仪、X射线衍射等方法,对文物的主要成分、制作工艺和锈蚀产物分别进行检测分析。初步确定文物的合金成分、锈蚀... 详细信息

为研究、保护和修复伊犁地区出土鎏金铜带饰,在现代保护修复理念的指导下,采用金相显微镜、X射线荧光、扫描电镜及X射线能谱仪、X射线衍射等方法,对文物的主要成分、制作工艺和锈蚀产物分别进行检测分析。初步确定文物的合金成分、锈蚀产物及病害种类,并对其保存状态进行评估,制定保护方案并实施科学保护。在有效保护文物的基础上,为揭示草原地区青铜文化提供重要参考。

关键词：伊犁青铜器科学分析保护

THE SYNTHESIS AND CRYSTAL STRUCTURE OF A CUBANE-LIKE MOLYBDENUM-COPPER-SULFUR CLUSTER {Mo3CuS4[S2P(OC2H5)2]3(I)(μ-CCl3(00)CH3CN}

在线全文

学校读者我要写书评

暂无评论

结构化学 1988年第2期 137-141页

作者： Wu Xintao Zheng yifan zhu Nianyong Lu JiaxiFuzhou Laboratory of Structural Chemistry, Fujian Institute of Research onthe Structure of Matter, Academia Sinica

The synthesis and crystal structure of the cubane-like cluste with [Mo3CuS4] core is reported herein. The title compound crystallizes i triclinic space group Pl with the following unit cell dimensions: a 11.723(3), b = 14.353(6), c = 15.533(4)A;α= 75.40(3)°,β=69.13(2)°,γ 64.93(3)°; Z = 2; V = 2196 A3; DC = 2.033 g·cm-3.7704 independent reflec tions were collected on CAM four-circle diffractoneter with MoKa radiatio in the range of 1 3σ(I). The structure was determined by direct methods and refined b the least-squares method to a final R index of 0.091. There are some distortion in the cubane-like [Mo3CuS4] core, with three Mo-Mo bonds and thre weak Mo-Cu bonds.

关键词： CuS OC2H5)2]3 CH3CN CCl3 THE SYNTHESIS AND CRYSTAL STRUCTURE OF A CUBANE-LIKE MOLYBDENUM-COPPER-SULFUR CLUSTER Mo3CuS4[S2P CN

The Spatial-Temporal Characteristics of Meteorological Disasters in the Southwest Region of Zhejiang Province during 1953-2022

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2024年第3期12卷 16-27页

作者： Qi Zhang yifan Wang Zhidan zhu Hongxia Shi Wenhao Yang Shujie Yuan Longyou Meteorological Administration Quzhou China School of Atmospheric Sciences Chengdu University of Information Technology Chengdu China

Meteorological disasters are some of the most serious and costly natural disasters, which have larger effects on economic and social activity. Liuchun Lake is an ecotourism area in the southwest region of Zhejiang province, where also has experienced meteorological disasters including rainstorm and cold wave. Understanding the temporal-spatial characteristics of meteorological disasters is important for the local tourism and economic development. Based on the daily temperature and precipitation from 18 meteorological stations in the southwest of Zhejiang province during 1953-2022 and some statistical approaches, the temporal and spatial characteristics of meteorological disasters (Freezing, Rainstorm, Cold wave) are analyzed. The results indicate that 1) Rainstorm occurred frequently around the Liuchun lake, the frequency was about 8 times/a, it can also reach about 3 times/a in the other region. Freezing and cold wave (including strong cold wave and extremely cold wave) had the same spatial distribution as rainstorm, however, except for Liuchun lake, they occurred less than one time in the other regions;2) The trend of rainstorm had larger spatial difference, it increased in all the study area, but it increased more significantly around the study area than around Liuchun lake. Freezing was on the downtrend in the whole region, with 93.3% of the stations passed the 95% significant level. Cold wave also showed a declined trend, but it was insignificantly at most of the stations, only 33% of the stations passed the 90% significant level. Compared with cold wave, strong cold wave and extremely strong cold wave had weaker decline in all the regions. In general, from 1953 to 2022 rainstorm showed an increasing trend, it was the main meteorological disaster in the study area, cold wave displayed a decreasing trend, but it still occurred about 2 - 3 times/a in most regions.

关键词： Southwest of Zhejiang Province Rainstorm Cold Wave Spatial Distribution Trend Analysis

面向复杂仿真元建模的序贯近邻探索实验设计方法

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

系统工程与电子技术 2021年第5期43卷 1232-1239页

作者：雷永林王言于芹章朱智董微朱一凡国防科技大学系统工程学院湖南长沙410073 复杂系统仿真总体重点实验室北京100010

复杂仿真影响因素多,影响关系非线性,需要高效的元建模方法。元模型的建立不仅取决于所选定的元模型数学结构,还取决于仿真训练数据的充分性。数据充分性直接影响到仿真实验空间的设计与实验运行的计算复杂度,需要通过针对性的仿真实验... 详细信息

复杂仿真影响因素多,影响关系非线性,需要高效的元建模方法。元模型的建立不仅取决于所选定的元模型数学结构,还取决于仿真训练数据的充分性。数据充分性直接影响到仿真实验空间的设计与实验运行的计算复杂度,需要通过针对性的仿真实验设计方法来应对维数爆炸困境。序贯实验设计方法可以有效提高设计的效率,但传统上的序贯方法依赖于人工干预和关于目标系统的先验知识,不易自动化开展。因此,提出一种支持仿真元建模的序贯近邻探索实验设计方法,该方法综合运用梯度采样与随机近邻探索技术,在产生尽可能少的实验点的同时,能够自动提取关于实验对象的信息,有效提高复杂仿真元建模的实验效率。案例部分将所提方法与拉丁超立方抽样、传统序贯采样两种方法进行了对比,验证了所提方法的有效性。

关键词：仿真元模型序贯实验设计近邻探索拉丁超立方抽样

Thirty Years of Experience of Acute Flaccid Paralysis Surveillance for Polio — China, 1993–2022

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2024年第16期6卷 344-349页

作者： Hong Yang Ning Wen Chunxiang Fan Fuzhen Wang Yong Zhang Lei Cao Shuangli zhu Lixin Hao Dongmei Yan Lei Wang Quanwei Song Miao Wang yifan Song Chao Ma Zhijie An Lance ERodewald Huaqing Wang Zundong Yin National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases(NITFID) BeijingChina National Immunization Program Chinese Center for Disease Control and PreventionBeijingChina Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina

Introduction:Detecting poliovirus infections proves to be highly challenging due to their asymptomatic nature and infectious potential,highlighting the crucial importance of effective detection methods in the context of polio eradication *** many countries,including China,the primary approach for identifying polio outbreaks has been through acute flaccid paralysis(AFP)*** this study,we conducted an evaluation spanning three decades(1993–2022)to assess the effectiveness of AFP surveillance in ***:Data on all AFP cases identified since 1993 and national-level AFP surveillance system quality indicators aligned with the World Health Organization(WHO)standards were collected for *** quality indicators assess surveillance sensitivity,completeness,timeliness of detection notification,case investigation,and laboratory *** sensitivity is determined by the non-polio AFP(NPAFP)detection rate among children under 15 years of ***:Between 1993 and 2022,a total of 150,779 AFP cases were identified and *** this pool,surveillance identified 95 cases of wild poliovirus(WPV)and 24 cases due to vaccinederived *** 1995 onwards,the detection rate of NPAFP cases consistently adhered to the WHO and national standards of≥1 case per 100,000,falling between 1.38 and *** in 1997,all timeliness indicators consistently achieved the criteria of 80%,apart from the consistency in meeting standards set for the rate of positive specimens sent to the national ***:AFP surveillance has been instrumental in China’s accomplishment of maintaining a polio-free *** ongoing adherence to key performance indicators,ensuring sensitivity and prompt specimen collection,demonstrates that AFP surveillance is proficient in detecting poliovirus in *** we move into the post-eradication phase,AFP surveillance remains crucial for the sustained absence of polioviruses in the long term.

关键词： sustained prompt surveillance

Non-cooperative Space Target Estimation Algorithm Without Prior Information Dependence Based on Temporal Line of Sight Constraint

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

Transactions of Nanjing University of Aeronautics and Astronautics 2024年第4期41卷 526-540页

作者： XIAO Hui zhu Chongrui LIU Xinqi YU yifan SHENG Qinghong YANG Rui College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China School of Environmental Science Nanjing Xiaozhuang UniversityNanjing 211171P.R.China

Under single-satellite observation,the parameter estimation of the boost phase of high-precision space noncooperative targets requires prior *** improve the accuracy without prior information,we propose a parameter estimation model of the boost phase based on trajectory plane parametric *** use of the plane passing through the geo-center and the cutting sequence line of sight(LOS)generates the trajectory-cutting *** the coefficient of the trajectory cutting plane directly used as the parameter to be estimated,a motion parameter estimation model in space non-cooperative targets is established,and the Gauss-Newton iteration method is used to solve the flight *** experimental results show that the estimation algorithm proposed in this paper weakly relies on prior information and has higher estimation accuracy,providing a practical new idea and method for the parameter estimation of space non-cooperative targets under single-satellite warning.

关键词： motion parameter estimation estimation of impact point infrared early warning boost phase modeling trajectory database construction

在线全文

学校读者我要写书评

暂无评论

人工智能时代的翻译人才培养:挑战与机遇

上海交通大学学报（哲学社会科学版） 2019年第4期27卷 37-45页

作者：朱一凡管新潮上海交通大学外国语学院

翻译专业的毕业生不得不面对机器翻译给语言服务行业带来的结构性变化。为了应对这种变化,未来的翻译人才培养目标需要逐渐从原先的专职翻译过渡到'翻译+语言工程师'的融合体。各院校还可根据学生背景的差异,制订差异化的培养方案,培养... 详细信息

翻译专业的毕业生不得不面对机器翻译给语言服务行业带来的结构性变化。为了应对这种变化,未来的翻译人才培养目标需要逐渐从原先的专职翻译过渡到'翻译+语言工程师'的融合体。各院校还可根据学生背景的差异,制订差异化的培养方案,培养'翻译为主+技术为辅'或'技术为主+翻译为辅'不同类型的翻译硕士。并根据培养目标和师资情况将涉及技术的课程模块有选择、有层级地加入课程体系中。

关键词：机器翻译翻译人才培养挑战机遇

在线全文

学校读者我要写书评

暂无评论

非合作跳频信号特征参数盲估计方法

兵器装备工程学报 2020年第4期41卷 162-166页

作者：张瑜朱一帆河南师范大学电子与电气工程学院河南新乡453007

针对使用谱图法的跳频信号特征参数盲估计实时性较好,但抗噪性和估计精度难以兼顾的问题,提出了一种基于时频分析的跳频信号特征参数盲估计方法。在短时傅里叶变换进行时频分析得到的跳频信号谱图基础上,利用能量检测的方法得到自适应... 详细信息

针对使用谱图法的跳频信号特征参数盲估计实时性较好,但抗噪性和估计精度难以兼顾的问题,提出了一种基于时频分析的跳频信号特征参数盲估计方法。在短时傅里叶变换进行时频分析得到的跳频信号谱图基础上,利用能量检测的方法得到自适应阈值对时频图进行修正。根据修正后的时频图,使用二次估计和信号DFT变换系数构造频率修正项方法来估计信号跳变时刻和载频频率,从而得到更为精确的特征参数估计值。仿真结果表明:该方法的参数估计精度、抗噪性和实时性都较好,能够满足实际应用要求。

关键词：跳频信号参数估计时频分析短时傅里叶变换 DFT插值

都市旅游视角下上海市共享住宿空间分布特征及其影响机制

在线全文

学校读者我要写书评

暂无评论

地理科学进展 2021年第8期40卷 1321-1331页

作者：朱怡帆何丹程庆杨娜康译之华东师范大学中国现代城市研究中心上海200062 华东师范大学城市与区域科学学院上海200241 华东师范大学地理科学学院上海200241

随着共享经济蓬勃发展,依托互联网平台的共享住宿业态也逐渐成熟,对社会经济发展产生了深刻影响。在都市和乡村共享住宿市场分异背景下,已有研究集中探讨了乡村民宿空间分布特征及影响因素,但对都市地区共享住宿分布特征的探讨有所忽视... 详细信息

随着共享经济蓬勃发展,依托互联网平台的共享住宿业态也逐渐成熟,对社会经济发展产生了深刻影响。在都市和乡村共享住宿市场分异背景下,已有研究集中探讨了乡村民宿空间分布特征及影响因素,但对都市地区共享住宿分布特征的探讨有所忽视。都市地区共享住宿与以观光、购物、文化体验等为特征的都市旅游活动关联密切。论文基于途家网的上海共享住宿房源相关数据,利用ArcGIS空间分析工具刻画了上海市共享住宿空间分布特征,并探究了都市旅游背景下共享住宿空间分布的影响机制。主要研究发现如下:(1)上海市共享住宿分布呈现"大集聚、小分散"与"双核心"的特征,主要集中在中心城区的旅游商业区和位于郊区的迪士尼乐园2大旅游热点区域,形成了显著的"旅游商业区效应"与"迪士尼效应";(2)共享住宿空间分布与上海市都市旅游活动密切相关,其空间集聚的产生是主体游客的行为决策与客体房源的区位条件之间供需作用的结果。最后,根据共享住宿集聚区差异化的影响机制,提出了针对性的政策建议。

关键词：共享住宿空间分布影响机制都市旅游上海市