期刊文献+
共找到994篇文章
< 1 2 50 >
每页显示 20 50 100
Clinical trial perspective for adult and juvenile Huntington's disease using genetically-engineered mesenchymal stem cells 被引量:7
1
作者 Peter Deng Audrey Torrest +4 位作者 Kari Pollock Heather Dahlenburg Geralyn Annett Jan A.Nolta Kyle D.Fink 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第5期702-705,共4页
Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells(MSC) to secrete brain-derived neurotrophic factor(BDNF) supports our plan to submit an Investigational N... Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells(MSC) to secrete brain-derived neurotrophic factor(BDNF) supports our plan to submit an Investigational New Drug application to the Food and Drug Administration for the future planned Phase 1 safety and tolerability trial of MSC/BDNF in patients with Huntington's disease(HD). There are also potential applications of this approach beyond HD. Our biological delivery system for BDNF sets the precedent for adult stem cell therapy in the brain and could potentially be modified for other neurodegenerative disorders such as amyotrophic lateral sclerosis(ALS), spinocerebellar ataxia(SCA), Alzheimer's disease, and some forms of Parkinson's disease. The MSC/BDNF product could also be considered for studies of regeneration in traumatic brain injury, spinal cord and peripheral nerve injury. This work also provides a platform for our future gene editing studies, since we will again use MSCs to deliver the needed molecules into the central nervous system. 展开更多
关键词 mesenchymal stem cells neurodegenerative disorders Huntington's disease genetic engineering brain derived neurotrophic factor
下载PDF
基于Pro/ENGINEER和3ds Max的缝纫机原理仿真动画制作研究
2
作者 苗苗 曹巨江 《CAD/CAM与制造业信息化》 2014年第3期56-58,共3页
缝纫机原理仿真动画对缝纫机主要功能零件模型的几何尺寸准确度要求较高,利用Pro/ENGINEER对缝纫机零部件进行精确建模和装配,将三维模型导入3ds?Max中进行材质渲染和动画制作,完成缝纫机原理仿真动画。充分发挥了Pro/ENGINEER和3ds?Ma... 缝纫机原理仿真动画对缝纫机主要功能零件模型的几何尺寸准确度要求较高,利用Pro/ENGINEER对缝纫机零部件进行精确建模和装配,将三维模型导入3ds?Max中进行材质渲染和动画制作,完成缝纫机原理仿真动画。充分发挥了Pro/ENGINEER和3ds?Max软件各自的优势,解决了单独使用3ds?Max软件在机构动画制作中零件的尺寸和装配不准确的问题,为机构仿真动画制作提供了新思路。 展开更多
关键词 仿真动画 PRO/engineer s MAX 动画制作 精确建模 零件模型 模型导入 针杆 机构组成 关键帧
下载PDF
Security Research on Engineering Database System
3
作者 REN Jian-ping 1,2, SONG Han-tao 2, LIANG Yun-rong 2 (1. North China Institute of Technology, Taiyuan 030051, China 2. Beijing Institute of Technology, Beijing 100081, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期288-289,共2页
Engine engineering database system is an oriented C AD applied database management system that has the capability managing distributed data. The paper discusses the security issue of the engine engineering database ma... Engine engineering database system is an oriented C AD applied database management system that has the capability managing distributed data. The paper discusses the security issue of the engine engineering database management system (EDBMS). Through studying and analyzing the database security, to draw a series of securi ty rules, which reach B1, level security standard. Which includes discretionary access control (DAC), mandatory access control (MAC) and audit. The EDBMS implem ents functions of DAC, MAC and multigranularity audit. DAC solves the problems o f role inheritance, right contain, authorization identify and cascade revoke, et c; MAC includes subject and object security setup rule, security modify rule and multilevel relation access operation rule, etc; Audit allows making the sub ject, object or operation type as different audit object to implement flexible a nd multigranularity audit method. The model is designed act as a security agent to access daemon database. At present, the model is implemented which runs on th e Windows 2000 environments. 展开更多
关键词 engineering database management system (EDBMs) s ecurity agent security level
下载PDF
Strategies for Improving the Effectiveness of Professional Practice for Full-Time Professional Master Degree Postgraduate in Mineral Processing Engineering 被引量:1
4
作者 Jiushuai Deng Juan Hu +3 位作者 Zhiqiang Xu Weidong Wang Zhongyi Bai Tingting Hu 《Journal of Contemporary Educational Research》 2023年第1期27-32,共6页
In order to gain practical experience and hands-on skills,full-time professional master degree postgraduate in mineral processing engineering should engage in professional practices.Nonetheless,a series of problems,in... In order to gain practical experience and hands-on skills,full-time professional master degree postgraduate in mineral processing engineering should engage in professional practices.Nonetheless,a series of problems,including insufficient time for practice,low management level,inadequate implementation of the double-supervisor system,and poor results of professional practice,has reduced the effectiveness of professional practice.In view of the aforementioned problems and the characteristics of the discipline,this paper proposes several strategies for improving the effectiveness of professional practice for postgraduates in mineral processing engineering. 展开更多
关键词 Mineral processing engineering FULL-TIME Application-oriented Master’s degree Professional practice
下载PDF
Bandgap engineering of hierarchical network-like SnIn4S8 microspheres through preparation temperature for excellent photocatalytic performance and high stability
5
作者 Jie Wang Min Liu +5 位作者 Mei Wang Yi Wang Aiting Zhang Xiang Zhao Guisheng Zeng Fang Deng 《Green Energy & Environment》 SCIE CSCD 2019年第3期264-269,共6页
The effect of synthesis temperature and reaction time on the visible-light photocatalytic activity of hierarchical network-like SnIn4S8 microspheres was investigated by the low-temperature co-precipitation strategy. T... The effect of synthesis temperature and reaction time on the visible-light photocatalytic activity of hierarchical network-like SnIn4S8 microspheres was investigated by the low-temperature co-precipitation strategy. The preparation temperature and reaction time have great influence on the photocatalytic activity of SnIn4S8, and the optimal preparation temperature and reaction time are 70℃ and 3 h, respectively.The SnIn4S8 shows good reusability and high stability with no observable decrease of photocatalytic activity in five consecutive cycles. 展开更多
关键词 snIn4s8 Bandgap engineerING synthesis TEMPERATURE REACTION time PHOTOCATALYTIC activity
下载PDF
Editor's Choice——Application of genetic engineering for the treatment of neurodegenerative diseases
6
《Neural Regeneration Research》 SCIE CAS CSCD 2011年第26期2012-2012,共1页
Gene therapy has been shown to be an effective method for protecting neural functions in the substantia nigra,
关键词 GENE Application of genetic engineering for the treatment of neurodegenerative diseases Editor’s Choice
下载PDF
A Software Engineering Project Course for Undergraduate Students
7
作者 LIU Jia Huang Zhi-jun Zhang Jin-yu 《计算机教育》 2012年第10期31-34,共4页
Software engineering(SE) courses are confronted with predicaments how to cultivate students' engineering concept and how to abridge the distance between the academy and industry.The "Computing and Software En... Software engineering(SE) courses are confronted with predicaments how to cultivate students' engineering concept and how to abridge the distance between the academy and industry.The "Computing and Software Engineering,III(CSE III)" helps students mimic a real-world software development and broaden realworld SE view.With the spiral model as the main development model,the CSE III course includes not only the SE theory knowledge,but also quick learning,team cooperation,development management and risk management skills which meet the real-world industry requirements.Our contribution is providing an introductory course for multiple dimensions of knowledge,creating a real-world software development circumstance for students under quantitative control and designing a systematic and practical evaluation mechanism which stimulates the interests of students.CSE III has been executed from 2009 and obtains a valuable teaching and learning effects among our teachers,TAs and students;and we add refinements to the course according to feedbacks of participants.This paper will describe the design and practice of the CSE III course. 展开更多
关键词 software engineering courses PROGRAMMING student’s feedback
下载PDF
China's Chemical Engineering Design Capability
8
作者 Zong Ri 《China's Foreign Trade》 1994年第12期39-40,共2页
During the early days of New China, to support the domestic construction of those projects aided by the former Soviet Union, the design institution formed a chemical engineering production installation design team. Du... During the early days of New China, to support the domestic construction of those projects aided by the former Soviet Union, the design institution formed a chemical engineering production installation design team. During the 1950s, this team designed an ammonia synthesis unit with an annual capacity of 75000 tons, set up the Sichuan Chemical Plant and worked out a 展开更多
关键词 DEsIGN China’s Chemical engineering Design Capability
下载PDF
Survey on <i>Essential and Accidental Real-Time Issues</i>in Software Engineering
9
作者 Furrakh Shahzad Dr. Maruf Pasha +2 位作者 Dr. Urooj Pasha Bushra Majeed Khurram Shahzad 《Journal of Software Engineering and Applications》 2017年第3期245-256,共12页
Software product lines have recently been presented as one of the best promis-ing improvements for the efficient software development. Different research works contribute supportive parameters and negotiations regardi... Software product lines have recently been presented as one of the best promis-ing improvements for the efficient software development. Different research works contribute supportive parameters and negotiations regarding the prob-lems of producing a perfect software scheme. Traditional approaches or recy-cling software are not effective to solve the problems concerning software competence. Since fast developments with software engineering in the past few years, studies show that some approaches are getting extensive attention in both industries and universities. This method is categorized as the software product line improvement;that supports reusing of software in big organizations. Different industries are adopting product lines to enhance efficiency and reduce operational expenses by way of emerging product developments. This research paper is formed to offer in-depth study regarding the software engineering issues such as complexity, conformity, changeability, invisibility, time constraints, budget constraints, and security. We have conducted various research surveys by visiting different professional software development organizations and took feedback from the professional software engineers to analyze the real-time problems that they are facing during the development process of software systems. Survey results proved that complexity is a most occurring issue that most software developers face while developing software applications. Moreover, invisibility is the problem that rarely happens according to the survey. 展开更多
关键词 sOFTWARE engineering IssUEs REAL-TIME sOFTWARE Development Problems Unexpected IssUEs of s.E
下载PDF
Review and Prospective on Systems Engineering in China
10
作者 XUE Huifeng 《Aerospace China》 2016年第1期37-41,共5页
The origin,formation and evolution of the systems engineering theory accompanied QIAN Xuesen's whole life.The systems engineering theory is the concentrated reflection of QIAN's achievements and theory in all ... The origin,formation and evolution of the systems engineering theory accompanied QIAN Xuesen's whole life.The systems engineering theory is the concentrated reflection of QIAN's achievements and theory in all aspects.From returning to China to pioneer China's space industry,creating a new management mode of "one overall design department,two command lines",publishing Organization and Management Technology:Systems Engineering,to proposing the theory of Open Complex Giant System(OCGS) and the theory of Metasynthetic Wisdom,all these mark the formation of the Chinese school of systems engineering.Guided by QIAN's academic ideas,various major Chinese space programs have been implemented successfully which verified the fact that the systems engineering is scientific.The systems engineering has been applied to different fields of the national economy and has a development process with the distinguished characteristics of Chinese systems science.On one hand,the systems engineering is put forward deeply along the traditional systems engineering thought and theory;on the other hand,a batch of innovations that break the traditional shackles have occurred,making the Chinese systems engineering unique and outstanding compared with foreign counterparts. 展开更多
关键词 systems engineering China's space industry sYsTEMATICs Comprehensive promotion
下载PDF
Fong’s National Engineering Shows More Details
11
《China Textile》 2008年第7期54-56,共3页
ECO-88D Double Rope High Speed Dyeing Machine ECO-88D Double Rope High Speed Dyeing Machine is suitable for the processing of light to medium weight fabric made from synthetic ber. Fabric structure suitable for the dy... ECO-88D Double Rope High Speed Dyeing Machine ECO-88D Double Rope High Speed Dyeing Machine is suitable for the processing of light to medium weight fabric made from synthetic ber. Fabric structure suitable for the dyeing process inside the ECO-88D includes woven, 展开更多
关键词 s National engineering shows More Details Fong
下载PDF
REFORMING CHINA'S HIGHER ENGINEERING EDUCATION
12
作者 Division of Technological Sciences, CAS 《Bulletin of the Chinese Academy of Sciences》 1996年第2期160-166,共7页
This article expounds that China’s higher engineering education is facing both challenges and opportunities. Some special difficulties and problems rise in the course of economic transition, and exhort us that it has... This article expounds that China’s higher engineering education is facing both challenges and opportunities. Some special difficulties and problems rise in the course of economic transition, and exhort us that it has been of great urgency to carry out a reform of higher engineering education. Here are put forward six measures: to explore training patterns of such an education suited to China’s national conditions; to improve university system: to transform educational ideology, and reform educational contents and methods; to establish a system of cooperation of engineering universities and colleges with industries; to strengthen construction of teacher contingent in engineering universities and colleges; and to carry out testing work of continuing engineering education and training education. 展开更多
关键词 REFORMING CHINA’s HIGHER engineerING EDUCATION WORK
下载PDF
Prospect and Retrospect of ECEPDI's Participation in Engineering Activities of Nuclear Power Projects
13
《Electricity》 1997年第4期7-10,共4页
关键词 Prospect and Retrospect of ECEPDI’s Participation in engineering Activities of Nuclear Power Projects
下载PDF
A PROPOSAL FOR DEVELOPING CHEMISTRY AND CHEMICAL ENGINEERING OF CHINA'S SALT LAKES
14
作者 CAS Division of Chemistry 《Bulletin of the Chinese Academy of Sciences》 1995年第1期39-44,共6页
The author puts forward a proposal for developing chemistry and chemical engineering of China’s salt lakes on the basis of an investigation into exploitation and utilization of salt lake resources all over the world.... The author puts forward a proposal for developing chemistry and chemical engineering of China’s salt lakes on the basis of an investigation into exploitation and utilization of salt lake resources all over the world. It contains the subjects of setting up an engineering research center, mainly developing leading products, giving priority to the development of a chemical industry by using Qinghai salt lake resources, actively popularizing results, stressing basic research and systematic management. 展开更多
关键词 A PROPOsAL FOR DEVELOPING CHEMIsTRY AND CHEMICAL engineerING OF CHINA’s sALT LAKEs LAKE
下载PDF
D-S理论和Markov链组合的桥梁性能退化预测研究
15
作者 杨国俊 田里 +2 位作者 唐光武 毛建博 杜永峰 《应用数学和力学》 CSCD 北大核心 2024年第4期416-428,共13页
为准确预测桥梁性能退化,考虑到数据随机性和微小扰动发生状态跳跃,提出了一种D-S(Dempster-Shafer)证据理论和Markov链组合的桥梁性能退化组合预测模型和性能退化率的概念.该模型基于指数平滑(exponential smoothing,ES)方法获得新的... 为准确预测桥梁性能退化,考虑到数据随机性和微小扰动发生状态跳跃,提出了一种D-S(Dempster-Shafer)证据理论和Markov链组合的桥梁性能退化组合预测模型和性能退化率的概念.该模型基于指数平滑(exponential smoothing,ES)方法获得新的预测数据序列,并利用Markov链和D-S理论不断进行优化,从而实现桥梁性能退化的组合预测.实际工程的应用结果表明:性能退化率可以直观地表征在梁性能退化的速度.其次,该模型的平均相对误差为1.54%,较于回归、灰色和模糊加权Markov链模型,精度分别提高了1.11%,0.88%和2.8%,而后验差比值为0.242,小于0.35;模型的标准差为9.021,相比其他模型分别减小了3.978,3.405和7.500,而变异系数为0.109,均小于其他模型,验证了组合预测模型在精度和稳定性方面的优越性,可为在役桥梁结构性能退化预测与维护提供理论基础. 展开更多
关键词 桥梁工程 性能退化预测 D-s证据理论 MARKOV链 组合预测模型 桥梁性能退化率
下载PDF
Agricultural Market Name Geo-Locating System Based on an Administrative Ontology and Web Search Engine 被引量:2
16
作者 HU Yi-min SONG Liang-tu +2 位作者 WEI Yuan-yuan HUANG He WANG Xue 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第5期849-857,共9页
The problem of associating the agricultural market names on web sites with their locations is essential for geographical analysis of the agricultural products. In this paper, an algorithm which employs the administrat... The problem of associating the agricultural market names on web sites with their locations is essential for geographical analysis of the agricultural products. In this paper, an algorithm which employs the administrative ontology and the statistics from the search results were proposed. The experiments with 100 market names collected from web sites were conducted. The experimental results demonstrate that the algorithm proposed obtains satisfactory performance in resolving the problem above, thus the effectiveness of the method is verified. 展开更多
关键词 agriculture markets geo-locating ONTOLOGY search engine Pearson's chi-square test
下载PDF
Design of automobile engine control system based on FlexRay bus
17
作者 潘辉 王义 《Journal of Measurement Science and Instrumentation》 CAS 2014年第3期64-68,共5页
FlexRay bus has become the standard of similar products and it will lead the direction of the development of auto- motive electronics control system for a long time. This paper proposes a design of automobile engine c... FlexRay bus has become the standard of similar products and it will lead the direction of the development of auto- motive electronics control system for a long time. This paper proposes a design of automobile engine control system based on FlexRay bus. In order to improve the network rate, reliability and flexibility, it adopts high-performance MC9S12XF512 microcontroller of Freescale and FlexRay bus driver TJA1080 of NXP company, and it gives the overall circuit design and software design process of automobile engine control system. The design has the characteristics of simple hardware circuit, high reliability and good real-time performance. It offers a certain reference value for the development of FlexRay bus node of engine control system. 展开更多
关键词 FLEXRAY automobile engine MC9s12XF512 TJA1080
下载PDF
应用PRO/ENGINEER开发机床夹具设计库 被引量:2
18
作者 赵北辰 罗永新 《齐齐哈尔大学学报(自然科学版)》 2002年第4期97-99,111,共4页
应用PRO/Engineer强大的功能模块,用成组技术的分类方法,创建机床标准组合夹具,建立和开发相应的标准件、通用件元件库,成形机床夹具设计库,进行机床夹具应用设计。这种机床夹具设计库开发应用简单,拓展容易。
关键词 PRO/engineer 机床夹具 设计库 成组技术 夹具设计 标准件 通用件 CAD
下载PDF
Progress in Technology of Main Liquid Rocket Engines of Launch Vehicles in China 被引量:8
19
作者 TAN Yonghua ZHAO Jian +1 位作者 CHEN Jianhua XU Zhiyu 《Aerospace China》 2020年第2期23-30,共8页
Liquid propellant rocket engines for a launch vehicle are an essential aerospace technology, representing the advanced level of hi-tech in a country. In recent years, China’s aerospace industry has made remarkable ac... Liquid propellant rocket engines for a launch vehicle are an essential aerospace technology, representing the advanced level of hi-tech in a country. In recent years, China’s aerospace industry has made remarkable achievements, and liquid rocket engine technology has also been effectively developed. In this article, the development processes of China’s liquid rocket engines are discussed. Then, the performance features of China’s new generation liquid rocket engines as well as the flight tests of the new-generation launch vehicles are introduced. Finally, the development direction and the most recent progress of the next generation large-thrust liquid rocket engine is presented. 展开更多
关键词 China’s aerospace industry liquid rocket engine technology progress
下载PDF
液压成形对液体火箭发动机多层增强S型波纹管结构疲劳寿命的影响 被引量:1
20
作者 张涵 张东升 朱卫平 《火箭推进》 CAS 北大核心 2024年第1期113-126,共14页
完善液体火箭发动机燃气摇摆装置中增强S型波纹管组件的疲劳寿命评估方法,提高其疲劳寿命预测精度,是发展可重复使用液体火箭发动机的重要课题之一。针对多层增强S型波纹管,为了计算其液压成形后的实际寿命数据,了解成形工艺对其疲劳寿... 完善液体火箭发动机燃气摇摆装置中增强S型波纹管组件的疲劳寿命评估方法,提高其疲劳寿命预测精度,是发展可重复使用液体火箭发动机的重要课题之一。针对多层增强S型波纹管,为了计算其液压成形后的实际寿命数据,了解成形工艺对其疲劳寿命的影响,提出一种充分考虑成形制备过程对结构不同区域几何构型和材料力学性能造成差异化影响后的波纹管疲劳寿命分析方法。该方法基于成形仿真和材料拉伸试验结果,构建实际波纹管有限元模型并进行三维仿真分析,得到其在高内压和不同摆动工况下结构危险点的循环载荷信息,并根据波纹管结构的低周疲劳失效特点采用子午向应力应变数据,以及经过平均应力应变修正的Manson-Coffin(M-C)公式对波纹管的循环寿命进行估算和对比分析。结果表明:波纹管疲劳寿命薄弱点位置和大小均与循环摆角有关;在预测计算中考虑液压成形作用影响更接近实际场景,所得结构疲劳寿命大小和所在区域均与理论模型值存在差异,在结构设计、优化和健康监测中不应忽视其影响。 展开更多
关键词 重复使用液体火箭发动机 增强s型波纹管 疲劳寿命 液压成形
下载PDF
上一页 1 2 50 下一页 到第
使用帮助 返回顶部