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Search Results: 1 - 10 of 93260 matches for " 冯伟 "
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非线性差分方程Xn=qx-1n-1+pxn-2解的性态
Properties of the Solution of the Nonlinear Difference Equation Xn=qx-1n-1+pxn-2
 [PDF]

, 宇辰
Pure Mathematics (PM) , 2015, DOI: 10.12677/PM.2015.55033
Abstract:
本文给出了差分方程Xn=qx-1n-1+pxn-2解的有界性的一个充分性条件,同时探讨了解了收敛性及二周期点存在的充分必要条件。
In this paper, we obtain one sufficient condition of the boundedness of equation X
n=qx-1n-1+pxn-2 , and discuss the convergence of the solution of equation and the sufficient and necessary condition of existence of the periodic point with period 2 of the equation.
基于网络的切换控制系统研究综述
Survey of Networked Control Systems Based on Switched Systems
 [PDF]

, 雒健
Artificial Intelligence and Robotics Research (AIRR) , 2013, DOI: 10.12677/AIRR.2013.23016
Abstract:
本文综述了网络切换控制系统的发展历史及研究现状,首先扼要回顾了切换控制系统相关问题和发展现状,其次介绍网络控制系统的主要特点和存在的问题,最终阐述了网络切换控制系统的产生、发展以及典型控制方法。通过对当前的网络切换控制系统的结构和特征进行分析研究,特别是对受控和非受控网络切换控制系统进行了重点分析。论文旨在从不同侧面探讨网络切换控制系统发展现状,并展望了其未来的发展情景。
In this paper, the past and current development of Networked Switched Control Systems (NSCS) are summarized briefly, and the related problems and main characteristics of the NSCS are introduced. And then, formation, development and the typical approaches for NSCS are discussed. Based on the current state of the NSCS, we also analyze the structure, characteristics of NSCS, especially the constrained and unconstrained switched systems. This paper aims to elaborate the present situation and control methods from various aspects of the NSCS. Finally, the paper discusses the future development of the NSCS.
放疗技术在肝癌治疗中的应用与研究进展
Research and Study on the Application of Radiotherapy Technique in the Treatment of Liver Cancer
 [PDF]

吴发,
World Journal of Cancer Research (WJCR) , 2015, DOI: 10.12677/WJCR.2015.52005
Abstract:
肝癌的放疗已有多年的历史,然而由于正常肝组织放射耐受性的限制,使所给剂量达不到肿瘤的根治剂量,治疗效果难以令人满意,以致长期以来不为人所接受,本文主要就现行的各种放疗技术在肝癌治疗中的应用与研究进行探讨,对肝癌的放射治疗进行有益的总结,并希望进一步提高肝癌的疗效,提高患者的生存质量。
Radiation therapy of liver cancer has had a history of many years. However, because of the limit of normal liver tissue radiation tolerance, the given tumor dose was less than a radical dose, thus leaded to unsatisfactory treatment, which resulted in a long time of not unaccepted. This paper focuses on the application and study of radiotherapy technique in the treatment of liver cancer. Firstly the type of liver cancer radiotherapy is studied and analyzed, which is followed by a dis-cussion of the radiation therapy of liver cancer from four areas, and provides a certain reference on similar studies.
高校环境教育新模式浅析—以福建省为例
Analysis of New Model of Environmental Education in Universities—Take Fujian Province as an Example
 [PDF]

, 程令
Sustainable Development (SD) , 2016, DOI: 10.12677/SD.2016.61007
Abstract:
面对日益恶化的自然环境,人们意识到进行环境教育,提升大众的环境意识是解决环境问题的根本途径。党的十八届五中全会将“绿色”作为“十三五”规划的重要理念,具有十分深远的意义。福建省植被覆盖率达61%以上,长久以来,福建省将生态文明大省作为自己的发展目标,环境建设也取得了一定的成就。但仍存在很多问题,特别是在高校环境教育方面。分析福建省环境教育现实问题,结合福建省具体情况,提出高校环境教育发展的“三元空间”模式,以期助力福建省高校环境教育发展。
In the face of the deteriorating natural environment, people get to realize that to carry on the en-vironmental education and enhance the public’s environmental consciousness is the fundamental way to solve the problem of environment. In the Fifth Plenum of the 18th Central Committee of the Communist Party of China, the government regards “green” as an important concept of the “Thir-teenth Five-Plan”, which has very far-reaching significance. The vegetation coverage of Fujian province is above 61%, and for a long time, Fujian province attaches much importance to the eco-logical civilization and regards it as its own development goals, which makes some achievements in environmental construction. But there still remain many problems, especially in the exploration of university environmental education. According to the reality and current situation of envi-ronmental education in Fujian province, the model of “three dimensions” is put forward to boost the development of environmental education in universities in Fujian Province.
发达国家环境教育模式探析及经验借鉴
Analysis of Developed Countries Environmental Education Mode and Experience for Reference
 [PDF]

, 程令
Advances in Social Sciences (ASS) , 2016, DOI: 10.12677/ASS.2016.51005
Abstract:
20世纪60年代以来,全球环境问题特别是发达国家日益突出,发达国家最早开始着手进行多方面的治理探索,并取得了较好效果。长期的环境治理经验使发达国家逐步认识到环境教育是进行环境治理的首要任务,高等院校是环境教育专题研究的主阵地,积累了丰富的环境教育经验。总结发达国家环境教育的实践经验,为创新我国的环境教育模式,创造有利的环境教育氛围,最终推进我国环境教育事业的新发展作出努力是本文探索的落脚点和归宿。
Since the 1960s, the global environment problem is increasingly prominent, especially in devel-oped countries. At the same time, developed countries began the governance exploration early and got good effects. Long-term environmental governance experience makes developed countries gradually realize that environmental education is the priority of environmental governance. In-stitutions of universities are the main land for environmental education research, having accu-mulated rich experiences in environmental education. The aim of this paper is to summarize the practice of environmental education experience of developed countries, to create new mode and establish favorable environmental education atmosphere, and ultimately to promote the devel-opment of our country’s environmental education.
心理折纸任务的难度衡量标准的建立
How to Develop a New Index to Measure the Difficulty Degree of Mental Paper-Folding
 [PDF]

, 成志
Advances in Psychology (AP) , 2016, DOI: 10.12677/AP.2016.63037
Abstract:
视觉空间能力能够较好的预测学业能力水平,甚至有的研究者提出,视觉空间能力是智力的一项独立的组成成分。而心理折纸任务作为衡量视觉空间能力的一种重要指标,在以往关于视觉空间能力的研究中却较少被使用。本研究旨在通过探求一种新的难度衡量指标——行列距离,用以衡量心理折纸任务的难易程度,从而筛选出有效的刺激材料,对心理折纸任务范式进行标准化。在本研究中,选取14名被试完成一系列心理折纸任务,并将折纸任务按照新旧两种难度衡量指标划分归类,最后比较在每一种分类中,个体的反应成绩的差异结果以及两种分类指标与反应成绩之间的相关关系。结果发现,采用行列距离作为衡量折纸任务难度的指标时,首先可以有效地减少心理折纸任务难度的划分层级。其次,被试在该指标所划分出的不同难度等级的心理折纸任务中的反应成绩差异显著。因此,本研究所采用的行列距离指标可以作为衡量心理折纸任务难度的重要指标,从而应用于心理折纸任务的刺激筛选与标准化以及其他应用研究中。
There is strong evidence linking spatial ability to academic achievement, and some researchers suggested that spatial ability is an independent component of intelligence. However a test of spatial ability paper-folding has seen relatively little study. In research we use a computational model to explore a new index to measure the degree of paper-folding test’s difficulty. We use Row and Column’s Distance to measure the difficulty of paper-folding test. In this study, we selected 14 subjects to finish a series of mental paper-folding tests, then compared the results of two different difficulty classifications tasks, finally we found when using Row and Column’s Distance as a mea-surement, we can reduce the difficulty levels of paper-folding test, and this index can effectively distinguish different difficulty levels. Therefore, the Row and Column’s Distance is an effectiveness index to distinguish the difficulty of paper-folding test and this index is better than the previous one. In future studies, we can use this index to filter stimulate of the mental paper-folding test and standardize this kind of task.
改革开放以来中国共产党人扶贫思想研究述评
The Research Review for Poverty Alleviation of the Communist Party of Chinese Communists’ Thoughts since the Reform and Opening-Up Policy
 [PDF]

, 邹金堂
Advances in Social Sciences (ASS) , 2016, DOI: 10.12677/ASS.2016.55102
Abstract:
贫困是世界各国尤其是发展中国家普遍面临的一个难题。对现今正处于全面建成小康社会的关键时期和攻坚阶段的中国而言,该问题的解决显得更为重要和迫切。从时间、空间、研究对象等方面对改革开放以来中国共产党人的扶贫思想进行系统梳理,可以使我们能对过去的扶贫经验和不足有一个较为全面的认识和把握,在此基础上,进一步改进和完善当前国家的扶贫政策,以期能够早日实现全部人口的脱贫,进而如期实现全面建成小康社会的目标。
Poverty is the universal problem that must be faced by the whole world, especially for the devel-oping countries. As for China, who is now in a critical period and a crucial stage of build a well-off society in an all-round way, the problem is more important and urgent. Studying the Chinese communists’ thoughts on poverty alleviation system from the aspects such as time, space, and study object of study since the reform and opening-up policy can make us have a more comprehensive understanding and grasp the past experience and insufficient for poverty alleviation. On this basis, further improving and perfecting the current national policy for poverty alleviation are helpful to make the whole population get rid of poverty and build a well-off society in an all-round way.
接触问题实体建模及有限元法仿真实现

武汉理工大学学报 , 2004,
Abstract: ?接触问题是摩擦学问题分析中重要的一部分,由于接触问题的非线性,使得工程分析研究较为困难。文中以球体静态接触为对象,建立模型并推导出赫兹接触应力、变形公式。通过利用有限元分析软件,采用点-面接触分析,对ansys有限元分析计算结果与推导公式计算的解进行比较,指出利用ansys求解实体表面接触问题是准确可靠的。研究结果表明,采用ansys有限元分析软件为分析摩擦学的表面接触问题提供了方法与途径。
基于掺加聚酯纤维的沥青混合料对比试验研究
Experiment Study on the Polyester Fiber Mix into Asphalt Mixture
 [PDF]

谢民, 宝平
Open Journal of Transportation Technologies (OJTT) , 2013, DOI: 10.12677/OJTT.2013.22025
Abstract:
文章对相同配合比的基质沥青、掺加4.5%SBS改性剂和同时掺加0.25%聚酯纤维与4.5%SBS改性剂的混合料分别进行了马歇尔稳定度试验、车辙试验、劈裂试验、残留稳定度和冻融劈裂试验,研究三种沥青混合料的马歇尔稳定度、水稳定性、高温稳定性及低温抗裂性。结果表明:掺加SBS改性剂和聚酯纤维后,沥青混合料的高温稳定性能得到改善。抗车辙能力和低温性能优劣依次为掺加聚酯纤维和SBS改性沥青混合料、SBS改性沥青混合料、基质沥青混合料。残留稳定度和冻融劈裂强度比的优劣顺序为:纤维沥青混合料、SBS改性沥青混合料、基质沥青混合料。
The paper analyzes three kinds of asphalt mixture with the same gradation mixture of matrix asphalt, adding 4.5% SBS modified mixes agent and simultaneously adding 0.25% polyester fiber and 4.5% SBS modifier. The three kinds of mixture are conducted by Marshall stability test, rutting test, split test, residual stability and freeze-thaw splitting test, aiming to properties of mixture Marshall stability, water stability, high temperature stability and low temperature crack resistance. The results show that the high temperature stability, asphalt mixture rutting resistance and low temperature properties of asphalt mixture can be improved by the addition of the SBS modifier and polyester fiber. Asphalt mixture with polyester fiber and SBS modifier is better than that of SBS modified asphalt and asphalt mixture in the aspects of rutting resistance, low temperature performance, water stability and freeze-thaw splitting strength ratio.
Pd-Ni/Al2O3催化合成四甲基二丙烯三胺研究
Pd-Ni/Al2O3 Catalyze Synthesis of 3,3’-Iminobis(N,N-dimethylpropylamine)
 [PDF]

刘威威,, 唐维克, 乙巳
Journal of Organic Chemistry Research (JOCR) , 2016, DOI: 10.12677/JOCR.2016.42006
Abstract:
本研究采用浸渍法制作了一系列的以γ-Al2O3为载体的Pd-Ni双金属纳米催化剂(Pd-Ni(x: y)/Al2O3;x和y分别是Pd-Ni的摩尔比),该催化剂用于二甲基丙二胺和二甲氨基丙腈加氢合成四甲基二丙烯三胺。并使用X射线衍射(XRD)、X电子光谱法(XPS)和透射电子显微镜法(TEM)对催化剂进行了表征。催化剂的活性随着Pd-Ni负载量的不同而变化。在所有催化剂中Pd-Ni/γ-Al2O3 (Pd:Ni = 1:2)表现出了最佳的催化活性,转化率在30%~40%,选择性达到90% (120?C, 最初氢气压力2 MPa, 8 h)。
Several γ-Al2O3 supported Pd-Ni bimetallic nanocatalysts (Pd-Ni(x:y)/Al2O3; where x and y repre-sent the mass ratio of Pd and Ni, respectively) were prepared by the impregnation method and used for selective hydrogenation of N,N-Dimethyl-1,3-propane diamine and Dimethylaminopropionitrile to 3,3’-iminobis(N,N-dimethylpropylamine). The Pd-Ni/Al2O3 samples were confirmed to have generated Pd-Ni bimetallic nanoparticles by X-ray diffraction (XRD), X-ray photoelectron spec-troscopy (XPS) and transmission electron microscopy (TEM). The catalytic activity was assessed in view of the effects of different mass ratios of Pd and Ni. Among all the samples, the Pd-Ni (1:2)/Al2O3 (PN-1:1) catalyst showed extremely high catalytic ability, which had 30% - 40% conversion rate and 90% selectivity (120?C, 2 MPa initial H2 pressure, 8 h).
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