我国大宗资源进口存在的问题以及对策     

王振新  应海松  杨东彪 《大众科技》2016,(5)

为加强大宗资源产品检验监管,保护贸易各方的利益,文章从检验检疫的视角对我国大宗资源存在的问题进行分析,提出应对策略,有效提升我国在大宗资源进口的主动权,确保我国大宗资源的能源供给安全,有效防范贸易风险。  相似文献   

Local and global approaches of affinity propagation clustering for large scale data   总被引：2，自引：0，他引：2  

Ding-yin Xia  Fei Wu  Xu-qing Zhang  Yue-ting Zhuang 《浙江大学学报(A卷英文版)》2008,9(10):1373-1381

Recently a new clustering algorithm called ＇affinity propagation＇ （AP） has been proposed, which efficiently clustered sparsely related data by passing messages between data points. However, we want to cluster large scale data where the similarities are not sparse in many cases. This paper presents two variants of AP for grouping large scale data with a dense similarity matrix. The local approach is partition affinity propagation （PAP） and the global method is landmark affinity propagation （LAP）. PAP passes messages in the subsets of data first and then merges them as the number of initial step of iterations; it can effectively reduce the number of iterations of clustering. LAP passes messages between the landmark data points first and then clusters non-landmark data points; it is a large global approximation method to speed up clustering. Experiments are conducted on many datasets, such as random data points, manifold subspaces, images of faces and Chinese calligraphy, and the results demonstrate that the two approaches are feasible and practicable.  相似文献   

确保供应链安全背景下,广东企业研究院的创建思路     

王卫红  张威 《科技管理研究》2020,40(24):138-143

受中美博弈、疫情冲击叠加影响可能出现的“逆全球化”甚至“去中国化”的环境背景下，为确保供应链安全，在广东大型企业创建研究院具有重要的战略意义和现实意义。研究广东大型制造业企业研究院的功能定位和主要作用，探讨创建企业研究院的思路及运行机制，为广东大型企业创建研究院提供对策建议。研究认为：应创建一批国家级和省级研究院；梳理重点产业的短板技术、关键技术瓶颈清单，支持企业研究院重点攻关；构建多元化、多层次投资机制，对承担清单上核心技术攻关的研究院重点支持；围绕确保供应链安全、做强产业链、部署创新链的目标，进行规划和政策制定；为大型企业研究院建设吸引、凝聚高端人才。  相似文献   

大系统思维—21世纪管理的主要思维方法     

代杰  赖晓鹏 《临沂师范学院学报》2001,23(2):8-10

大系统思维是随着时代发展而出现的一种新的思维方法，它的特征和原则决定它必然成为21世纪管理的主要思维方法。  相似文献   

狂欢的符号--大型电视平民选秀节目的文化阐释   总被引：1，自引：0，他引：1  

田中阳  赵颖峰 《湖南大众传媒职业技术学院学报》2006,6(3):19-21

自2004年以来,大型电视平民选秀节目愈演愈盛,对其评价也褒贬不一。本文从符号学理论与狂欢节理论角度切入,以《超级女声》为文本,对这类型节目进行文化解释。该类节目在满足广大受众对颠覆层级及建构乌托邦式理想生活的欲望的同时成为缓解社会焦虑的“溢洪道”,从而起到维持现有社会秩序正常持续运转的重要作用。  相似文献   

What changes,and for whom? A study of the impact of learning analytics-based process feedback in a large course     

《Learning and Instruction》2021

Recent developments in educational technologies have provided a viable solution to the challenges associated with scaling personalised feedback to students. However, there is currently little empirical evidence about the impact such scaled feedback has on student learning progress and study behaviour. This paper presents the findings of a study that looked at the impact of a learning analytics (LA)-based feedback system on students' self-regulated learning and academic achievement in a large, first-year undergraduate course. Using the COPES model of self-regulated learning (SRL), we analysed the learning operations of students, by way of log data from the learning management system and e-book, as well as the products of SRL, namely, performance on course assessments, from three years of course offerings. The latest course offering involved an intervention condition that made use of an educational technology to provide LA-based process feedback. Propensity score matching was employed to match a control group to the student cohort enrolled in the latest course offering, creating two equal-sized groups of students who received the feedback (the experimental group) and those who did not (the control group). Growth mixture modelling and mixed between-within ANOVA were also employed to identify differences in the patterns of online self-regulated learning operations over the course of the semester. The results showed that the experimental group showed significantly different patterns in their learning operations and performed better in terms of final grades. Moreover, there was no difference in the effect of feedback on final grades among students with different prior academic achievement scores, indicating that the LA-based feedback deployed in this course is able to support students’ learning, regardless of prior academic standing.  相似文献   

云南省三大体育场馆经营管理模式比较研究     

史永 《鞍山师范学院学报》2013,(6):81-84

主要采用文献资料法、专家访谈法、逻辑分析与比较研究相结合的方法,经实地考查后,运用管理学、经济学等相关学科知识对目前云南省内的体育场馆经营管理模式及其经营管理现状进行研究。在对云南省3个大中型体育场馆中的产权、经营权和经营管理的投入产出进行比较分析后,发现其经营管理中的不足,为云南省内的大中型体育场馆的发展提供理论依据及借鉴意义。  相似文献   

公共课教育学大班教学的困境与对策     

李瑛 《巢湖学院学报》2012,(2):127-131

近年来,高校扩招使得教学资源相对短缺,公共课教育学大班教学成为普遍现象,面临着学科地位尴尬、教学内容僵化庞杂、课堂缺乏吸引力、教学秩序差、师生关系不融洽等困境,学生厌学,教师厌教,降低了教学成效。必须采取有效措施,促进公共课教育学大班教学尽快走出窘境,真正发挥其在师范生专业培养中的独特作用。  相似文献   

Evaluation of sodium nitrite as a corrosion inhibitor for USS Monitor artifacts     

none 《文物保护研究》2013,58(4):253-266

Abstract

The use of sodium nitrite (NaNO₂) as a corrosion inhibitor for wet archeological metal objects presents potential advantages of near neutral pH, low concentration, effectiveness on several metals, and compatibility with organic materials. The effectiveness of NaNO₂ as a corrosion inhibitor for storage of chloride-containing marine archeological metal objects from the wreck of the USS Monitor was evaluated using marine-corroded carbon steel analogs. The samples were tested in varying concentrations of NaNO₂ and evaluated visually and by monitoring solution chemistry using ion chromatography (IC). It was found that a concentration of 1000 ppm NaNO₂, replaced four times, was effective at protecting corroded carbon steel in the presence of chlorides. Nitrite solutions were no more rapid than sodium hydroxide (NaOH) at extracting chlorides from marine steel at equal concentrations and were considerably slower than 2% NaOH. IC analyses indicated that NO₂ does not easily oxidize to NO₃ under normal conditions, but does so readily when a polarizing current is applied, making nitrites unsuitable for electrolytic reduction treatments. Sodium nitrite does show promise as a storage solution prior to desalination of marine metals or after desalination to prevent flash corrosion during rinsing baths.  相似文献   

大型体育场馆周边地区产业开发研究——基于西安市的个案研究     

成彦开  张金桥 《四川体育科学》2013,(6):4-7,11

运用文献综述、实地调查、逻辑分析等方法,以西安市的三大体育场馆——陕西省体育场、西安城市运动公园、陕西省体育训练中心为例,对大型体育场馆周边地区产业开发情况进行研究。研究发现：大型体育场馆周边产业开发存在着一些相同之处,但在开发的种类、规模、侧重点上也表现出明显区别。大型体育场馆周边地区产业开发出现差异与场馆的地理位置、周边活动人群、功能定位等有着密切关系。在以上分析的基础上,结合各大场馆自身的特点,提出了相应的对策建议。  相似文献