首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2998篇
  免费   130篇
  国内免费   5篇
电工技术   30篇
综合类   21篇
化学工业   854篇
金属工艺   60篇
机械仪表   42篇
建筑科学   157篇
矿业工程   3篇
能源动力   35篇
轻工业   283篇
水利工程   18篇
石油天然气   3篇
无线电   217篇
一般工业技术   547篇
冶金工业   411篇
原子能技术   25篇
自动化技术   427篇
  2023年   36篇
  2022年   59篇
  2021年   85篇
  2020年   55篇
  2019年   58篇
  2018年   59篇
  2017年   55篇
  2016年   69篇
  2015年   68篇
  2014年   92篇
  2013年   130篇
  2012年   122篇
  2011年   206篇
  2010年   138篇
  2009年   150篇
  2008年   135篇
  2007年   121篇
  2006年   125篇
  2005年   95篇
  2004年   92篇
  2003年   85篇
  2002年   85篇
  2001年   77篇
  2000年   73篇
  1999年   73篇
  1998年   123篇
  1997年   91篇
  1996年   66篇
  1995年   57篇
  1994年   47篇
  1993年   45篇
  1992年   23篇
  1991年   35篇
  1990年   33篇
  1989年   29篇
  1988年   18篇
  1987年   13篇
  1986年   9篇
  1985年   15篇
  1984年   16篇
  1983年   14篇
  1982年   10篇
  1981年   8篇
  1980年   9篇
  1979年   9篇
  1978年   11篇
  1977年   20篇
  1976年   19篇
  1967年   6篇
  1966年   8篇
排序方式: 共有3133条查询结果,搜索用时 15 毫秒
1.
2.
3.
介绍了德国HA公司最新研制的CORDIS无机粘结剂的组成与性能以及应用中的问题。  相似文献   
4.
Using a Debye function analysis, the presence of icosahedral and face centered cuboctahedral gold in a 1 1 ratio has been found in freshly prepared Au/Mg(OH)2 catalyst. The results support earlier studies which suggest the icosahedral form to be more stable at small nanometer sizes. Interactions between the gold and the Mg(OH)2 support appear to be weak, with the gold rapidly coagulating over a period of three months. Re-analysis of the aged sample shows the gold to be mainly in the form of truncated decahedra.  相似文献   
5.
6.

Fall und Kommentare

Gibt es eine Pflicht zum pr?natalen Nichtwissen?  相似文献   
7.
Integrating products and services to customized solutions can help firms to differentiate from their competitors. In practice, however, various companies fall short in extracting value from their customers. Therefore this paper focuses on pricing aspects as central means for value appropriation in the context of solutions. Following the resource-based view of the firm, we adopt a process-oriented perspective on pricing practices in order to identify crucial factors and activities. Based on 15 in-depth interviews with practitioners from various industries we derive six steps of a price management process for value appropriation in the context of solution selling and present critical activities and routines within each step.  相似文献   
8.
Confronted with decreasing margins and a rising customer demand for integrated solutions, manufacturing companies integrate complementary services into their portfolio. Offering value bundles (consisting of services and physical goods) takes place in integrated product–service systems, spanning the coordinated design and delivery of services and physical goods for customers. Conceptual Modeling is an established approach to support and guide such efforts. Using a framework for the design and delivery of value bundles as an analytical lens, this study evaluates the current support of reference models and modeling languages for setting up conceptual models for an integrated design and delivery of value bundles. Consecutively, designing modeling languages and reference models to fit the requirements of conceptual models in product–service systems are presented as upcoming challenges in Service Research. To guide further research, first steps are proposed by exemplarily integrating reference models and modeling languages stemming from the service and manufacturing domains.  相似文献   
9.
Modern businesses are facing the challenge of effectively coordinating their supply chains from upstream to downstream services. It is a complex problem to search, schedule, and coordinate a set of services from a large number of service resources under various constraints and uncertainties. Existing approaches to this problem have relied on complete information regarding service requirements and resources, without adequately addressing the dynamics and uncertainties of the environments. The real-world situations are complicated as a result of ambiguity in the requirements of the services, the uncertainty of solutions from service providers, and the interdependencies among the services to be composed. This paper investigates the complexity of supply chain formation and proposes an agent-mediated coordination approach. Each agent works as a broker for each service type, dedicated to selecting solutions for each service as well as interacting with other agents in refining the decision making to achieve compatibility among the solutions. The coordination among agents concerns decision making at strategic, tactical, and operational level. At the strategic level, agents communicate and negotiate for supply chain formation; at the tactical level, argumentation is used by agents to communicate and understand the preferences and constraints of each other; at the operational level, different strategies are used for selecting the preferences. Based on this approach, a prototype has been implemented with simulated experiments highlighting the effectiveness of the approach.  相似文献   
10.
Recent developments in the area of decentralized and infrastructureless systems opened avenues for novel applications. Along with these new technologies, new questions regarding their operational bounds in terms of e.g. scalability and security arose. Due to the sparse presence of real-world decentralized and infrastructureless systems, new protocols and applications have to be scrutinized by means of simulation, in (small-scale) testbeds, and by analytical models. In this paper, we discuss challenges of evaluating security mechanisms for mobile ad hoc networks and peer-to-peer systems. We focus on harmonizing predictions of analytical models and results obtained from simulation studies and testbed experiments.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号