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   63篇
  免费   3篇
电工技术   1篇
化学工业   22篇
能源动力   4篇
轻工业   2篇
无线电   1篇
一般工业技术   16篇
冶金工业   4篇
自动化技术   16篇
  2023年   1篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   4篇
  2017年   3篇
  2015年   2篇
  2014年   2篇
  2013年   2篇
  2012年   5篇
  2011年   3篇
  2010年   4篇
  2008年   4篇
  2007年   1篇
  2005年   2篇
  2004年   1篇
  2003年   1篇
  2000年   2篇
  1999年   1篇
  1998年   3篇
  1996年   1篇
  1994年   1篇
  1988年   2篇
  1986年   1篇
  1983年   2篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
  1970年   3篇
  1969年   2篇
  1968年   2篇
排序方式: 共有66条查询结果,搜索用时 15 毫秒
61.
With the explosive growth of the World Wide Web, it is becoming increasingly difficult for users to collect and analyze Web pages that are relevant to a particular topic. To address this problem we are developing WTMS, a system for Web topic management. In this paper we explain how the WTMS crawler efficiently collects Web pages for a topic. We also introduce the user interface of the system that integrates several techniques for analyzing the collection. Moreover, we present the various views of the interface that allow navigation through the information space. We highlight several examples to show how the system enables the user to gain useful insights about the collection.  相似文献   
62.
For any memoryless communication channel with a binary-valued input and a one-dimensional real-valued output, we introduce a probabilistic lower bound on the mutual information given empirical observations on the channel. The bound is built on the Dvoretzky-Kiefer-Wolfowitz inequality and is distribution free. A quadratic time algorithm is described for computing the bound and its corresponding class-conditional distribution functions. We compare our approach to existing techniques and show the superiority of our bound to a method inspired by Fano's inequality where the continuous random variable is discretized.  相似文献   
63.
64.
BACKGROUND: Hand eczema (HE) is a chronic multifactorial dermatosis with the presence of endogenous and exogenous factors in its pathogenesis. The etiologic diagnosis of hand eczema is often difficult. OBJECTIVES: The objectives of this study were (1) to detect clinical history and clinical examination data capable of differentiating HE types; (2) to determine the importance of patch tests for the etiologic diagnosis of HE; and (3) on the basis of the definitive diagnosis of HE type with the aid of patch tests, to obtain relevant data for appropriate patient guidance for the control of HE. METHODS: A total of 250 patients with HE were studied over a period of 3 years (1993 to 1995). All patients were submitted to the battery of patch tests. RESULTS AND CONCLUSIONS: The results obtained led to the following conclusions: (1) Women are more predisposed to HE. (2) Work under moist conditions favors HE. (3) With respect to the regional location of HE, any region may be involved in any type of HE; however, involvement of the dorsal region is more common in allergic contact dermatitis (ACD), followed by contact dermatitis owing to primary irritation (ICD) and atopic dermatitis (AD). Location of HE on the dorsal surface of the fingers was mainly observed in ACD, followed by ICD and AD. (4) Patch tests should be part of the investigative routine of HE etiology. (5) The presence of allergy to metals in the clinical history of the patient is a relevant feature, because patch tests confirmed sensitization to nickel in 89% of cases. (6) Rubber components have high sensitization frequency in patients with HE. (7) When the patient reports worsening of HE after the use of rubber gloves, this indicates a probable sensitization to rubber components, mainly in patients with AD.  相似文献   
65.
Random Fibonacci sequences are stochastic versions of the classical Fibonacci sequence fn+1=fn+fn?1 for n>0, and f0=f1=1, obtained by randomizing one or both signs on the right side of the defining equation and/or adding a “growth parameter.” These sequences may be viewed as coming from a sequence of products of i.i.d. random matrices and their rate of growth measured by the associated Lyapunov exponent. Following the techniques presented by Embree and Trefethen in their numerical paper Embree and Trefethen (1999) [2], we study the behavior of the Lyapunov exponents as a function of the probability p of choosing + in the sign randomization.  相似文献   
66.
Clean Technologies and Environmental Policy - A major concern for the modern world is to deal with environmental issues without compromising on economic growth targets. Energy use from renewable...  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