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   668篇
  免费   31篇
电工技术   7篇
化学工业   175篇
金属工艺   8篇
机械仪表   10篇
建筑科学   93篇
能源动力   7篇
轻工业   39篇
水利工程   3篇
石油天然气   2篇
无线电   20篇
一般工业技术   129篇
冶金工业   85篇
原子能技术   1篇
自动化技术   120篇
  2023年   5篇
  2022年   11篇
  2021年   16篇
  2020年   7篇
  2019年   16篇
  2018年   14篇
  2017年   10篇
  2016年   15篇
  2015年   29篇
  2014年   26篇
  2013年   42篇
  2012年   37篇
  2011年   37篇
  2010年   21篇
  2009年   29篇
  2008年   39篇
  2007年   31篇
  2006年   33篇
  2005年   40篇
  2004年   18篇
  2003年   15篇
  2002年   15篇
  2001年   11篇
  2000年   11篇
  1999年   13篇
  1998年   30篇
  1997年   25篇
  1996年   10篇
  1995年   12篇
  1994年   12篇
  1993年   11篇
  1992年   7篇
  1991年   6篇
  1990年   3篇
  1989年   3篇
  1988年   5篇
  1987年   5篇
  1986年   3篇
  1985年   4篇
  1984年   2篇
  1982年   4篇
  1980年   1篇
  1979年   3篇
  1977年   1篇
  1976年   3篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1967年   1篇
  1959年   1篇
排序方式: 共有699条查询结果,搜索用时 15 毫秒
1.
2.
3.
在当今企业环境日益复杂而活跃的背景条件下,企业需要不断进行重组和迅速转型。这要求企业要具备更强的适应性和更高的灵活性。为了确保实现这些动态的要求,企业必须制定和实施新型的组织形式。本文介绍过程链管理——一种面向过程进行转型的工具。本文首先简要说明了过程链管理应用的工具、过程链管理的任务和构造。它的出发点是由行动、结构、资源、和指挥所组成的过程链管理。在第二步骤中,重点阐述了客户取向这个过程链管理中最重要的取向量。总体来说,整个价值创造链及与此相关的内部交换关系都具有重要意义。在对过程链管理的方法进行了说明以后,提出了一个应用实例,该实例不仅描述了垂直重构,也对水平重构进行了描述。  相似文献   
4.
Consumer electronics has played an important role in the development of integrated circuit technology. Inversely, the integrated circuit has made possible low-cost but highly complex products that we have come to depend upon for enjoyment and convenience in our lives as family units or individual consumers. Integrated circuit production economics favor volume applications and the ”one per human being” opportunity presented by consumer products can be a powerful driver. The performance requirements for consumer applications, including low cost, low power, battery operation, nonvolatile memory, high-frequency amplification and scanning, lightweight and pleasing as well as convenient input/output means have led to many innovations in the evolution of the integrated circuit  相似文献   
5.
In the framework of the European research project PV2GO, a new AC-module inverter was developed, taking into account all relevant aspects from a European market's point of view (standards, market, application, and research and development goals). The project goal was to achieve the overall system costs of 3 Euro per Wp for a modular plug-and-play photovoltaic system. For the photovoltaic-module, a standard 130-Wp Eurosolare module was chosen. The research and development (R&D) goal was to develop an advanced DC-control system consisting of a state-of-the-art programmable digital device and an Application Specific Integrated Circuit (ASIC) for the AC-control of the inverter. According to the topology concept, thermal and magnetic designs were optimized with regard to production technology and packaging for large-scale production. The new AC-modules were tested in a number of field-test sites in various parts of Europe and their reliability was assessed through Highly Accelerated Stress Tests. Efficiency and power quality have been tested in the laboratory. Further in the PV2GO project an optimization study of the manufacturing process of the new generation of AC-modules for high volume output was done. Another task was the pre-certification procedure to assure compliance with the European guidelines and standards.  相似文献   
6.
It has been suggested recently that in congenitally hypothyroid infants with organification defect there is a maternal-fetal transfer of thyroxine (T4). The present study was conducted to evaluate how effective the maternal-fetal transfer is and whether the maternal T4 can prevent intrauterine hypothyroidism. The clinical, laboratory and radiological data on 271 full-term infants with persistent primary congenital hypothyroidism, detected by the national screening program, were used to assess the degree of in utero hypothyroidism. For 6 out of 50 athyroid infants, two pretreatment blood samples spotted on filter paper were available for calculating the T4 disappearance rate. Most infants with agenesis of the thyroid had very low T4 and very high levels of thyroid-stimulating hormone compared to infants with ectopic thyroid. In the athyroid infants the initial T4 declined to low and undetectable levels. Bone maturation was significantly delayed while the clinical symptomatology was more prominent in the athyroid congenital hypothyroid infants, as compared with the ectopic thyroid infants. In conclusion, there is some maternal-fetal transfer of T4. However, this transfer is insufficient to suppress the fetal levels of thyroid-stimulating hormone and prevent intrauterine hypothyroidism.  相似文献   
7.
Nine isolates of bacteria biochemically resembling Shigella dysenteriae but not belonging to the 10 recognized serotypes were isolated from patients with diarrhea in Bangladesh. Further studies suggested that two, one, and six isolates belonged to the recently recognized S. dysenteriae serotypes 11, 12, and 13, respectively.  相似文献   
8.
Text displayed in a video is an essential part for the high-level semantic information of the video content. Therefore, video text can be used as a valuable source for automated video indexing in digital video libraries. In this paper, we propose a workflow for video text detection and recognition. In the text detection stage, we have developed a fast localization-verification scheme, in which an edge-based multi-scale text detector first identifies potential text candidates with high recall rate. Then, detected candidate text lines are refined by using an image entropy-based filter. Finally, Stroke Width Transform (SWT)- and Support Vector Machine (SVM)-based verification procedures are applied to eliminate the false alarms. For text recognition, we have developed a novel skeleton-based binarization method in order to separate text from complex backgrounds to make it processible for standard OCR (Optical Character Recognition) software. Operability and accuracy of proposed text detection and binarization methods have been evaluated by using publicly available test data sets.  相似文献   
9.
10.
From 25 to 27 Sept 1997, a workshop was organized at the Essen Medical School (Universit?tsklinikum Essen), at which radiooncologists and jurists from universities and courts as well as lawyers contributed their views on mutual problems. The following topics were discussed by papers and in round table meetings: "Requirements on the patient's information", "definition of therapeutic guidelines-limits of clinical research and standard treatments", "treatment documentation", "liability of the physician for treatment faults" and "technical standard and preserve of quality". The consensual guidelines to the topics "patient's information", "therapeutic guidelines" and "liability" are presented here.  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