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   2532篇
  免费   70篇
  国内免费   15篇
电工技术   52篇
综合类   3篇
化学工业   475篇
金属工艺   89篇
机械仪表   97篇
建筑科学   37篇
能源动力   137篇
轻工业   93篇
水利工程   19篇
石油天然气   8篇
无线电   419篇
一般工业技术   532篇
冶金工业   267篇
原子能技术   21篇
自动化技术   368篇
  2024年   11篇
  2023年   36篇
  2022年   73篇
  2021年   116篇
  2020年   77篇
  2019年   69篇
  2018年   91篇
  2017年   66篇
  2016年   95篇
  2015年   43篇
  2014年   96篇
  2013年   141篇
  2012年   111篇
  2011年   125篇
  2010年   102篇
  2009年   119篇
  2008年   105篇
  2007年   91篇
  2006年   78篇
  2005年   65篇
  2004年   64篇
  2003年   60篇
  2002年   52篇
  2001年   40篇
  2000年   37篇
  1999年   27篇
  1998年   52篇
  1997年   36篇
  1996年   39篇
  1995年   46篇
  1994年   35篇
  1993年   26篇
  1992年   34篇
  1991年   41篇
  1990年   27篇
  1989年   36篇
  1988年   26篇
  1987年   20篇
  1986年   13篇
  1985年   36篇
  1984年   31篇
  1983年   16篇
  1982年   20篇
  1981年   14篇
  1980年   8篇
  1979年   11篇
  1978年   8篇
  1977年   10篇
  1976年   17篇
  1973年   7篇
排序方式: 共有2617条查询结果,搜索用时 15 毫秒
1.
Neural Processing Letters - The uncertainty caused mainly by the deficiency of precision and data, artificial/human-made errors, information accessed from expert opinions or very miniature size of...  相似文献   
2.
3.
4.
Proficiency on underlying mechanism of rubber-metal adhesion has been increased significantly in the last few decades. Researchers have investigated the effect of various ingredients, such as hexamethoxymethyl melamine, resorcinol, cobalt stearate, and silica, on rubber-metal interface. The role of each ingredient on rubber-metal interfacial adhesion is still a subject of scrutiny. In this article, a typical belt skim compound of truck radial tire is selected and the effect of each adhesive ingredient on adhesion strength is explored. Out of these ingredients, the effect of cobalt stearate is found noteworthy. It has improved adhesion strength by 12% (without aging) and by 11% (humid-aged), respectively, over control compound. For detailed understanding of the effect of cobalt stearate on adhesion, scanning electron microscopy and energy dispersive spectroscopy are utilized to ascertain the rubber coverage and distribution of elements. X-ray photoelectron spectroscopy results helped us to understand the impact of CuXS layer depth on rubber-metal adhesion. The depth profile of the CuXS layer was found to be one of the dominant factors of rubber-metal adhesion retention. Thus, this study has made an attempt to find the impact of different adhesive ingredients on the formation of CuXS layer depth at rubber-metal interface and establish a correlation with adhesion strength simultaneously.  相似文献   
5.
6.
A three dimensional, transient model is developed for studying heat transfer, fluid flow and mass transfer for the case of a single-pass laser surface alloying process. The numerical study is performed in a co-ordinate system fixed to the laser which moves with a constant scanning speed. The coupled momentum, energy and species conservation equations are solved using a finite volume technique. Phase change processes are modelled using a fixed-grid enthalpy-porosity technique, which is capable of predicting the continuously evolving solid-liquid interface. The three-dimensional model is able to predict the species concentration distribution inside the molten pool during alloying, as well as in the entire cross section of the solidified alloy. Corresponding experimental results show a good qualitative agreement with the numerical predictions with regard to pool shape and final composition distribution.  相似文献   
7.
Lean philosophy: implementation in a forging company   总被引:2,自引:2,他引:0  
This research addresses the implementation of lean philosophy in a forging company with a focus on radial forging production flow lines. Here, the prime motive is to evolve and test several strategies to eliminate waste on the shop floor. In this research, a systematic approach is suggested for the implementation of lean principles. This paper describes an application of value stream mapping (VSM). Consequently, the present and future states of value stream maps are constructed to improve the production process by identifying waste and its sources. Furthermore, Taguchi’s method of design of experiments is pursued here to minimize the forging defects produced due to imperfect operating conditions. A noticeable reduction in set-up time and work-in-process (WIP) inventory level is substantiated. Finally, we conclude with a discussion of managerial implications and the future scope of research.  相似文献   
8.
This paper deals with the design of a multi-slot hole-coupled microstrip antenna on a substrate of 2 mm thickness that gives multi-frequency (wideband) characteristics. The Method of Moments (MoM)-based IE3D software was used to simulate the results for return loss, VSWR, the Smith chart, and the radiation patterns. A tunnel-based artificial neural network (ANN) was also developed to calculate the radiation patterns of the antenna. The radiation patterns were measured experimentally at 10.5 GHz and 12 GHz. The experimental results were in good agreement with the simulated results from IE3D and those of the artificial neural network. A new method of using a genetic algorithm (GA) in an artificial neural network is also discussed. This new method was used to calculate the resonant frequency of a single-shorting-post microstrip antenna. The resonant frequency calculated using the genetic-algorithm-coupled artificial neural network was compared with the analytical and experimental results. The results obtained were in very good agreement with the experimental results.  相似文献   
9.
Densification of a-Sic powders with no premixed sintering aids (type 1) and with premixed B and C (type 2) was investigated by sintering them at 2150° to 2200°C for 30 min. Flexure strengths, Weibull moduli, and fracture flaws were characterized for type 2 α-SiC only. The results were compared with those for a state-of-the-art sintered a-Sic material.  相似文献   
10.
The Design of Discrimination Experiments   总被引:1,自引:0,他引:1  
Experimentation plays a fundamental role in scientific discovery. Scientists experiment to gather data, investigate phenomena, measure quantities, and test theories. In this article, we address the problem of designing experiments to discriminate between two completing theories. Given an initial situation for which the two theories make the same prediction, the experiment design problem is to determine how to modify the situation such that the two theories make different predictions for the modified situation. The modified situation is called a discrimination experiment. We present a knowledge-intensive method called DEED for designing discrimination experiments. The method analyzes the differences in the two theories' explanations of the prediction for the initial situation. Based on this analysis, it determines modifications to the initial situation that will result in a discrimination experiment. We illustrate the method with the design of experiments to discriminate between several pairs of qualitative theories in the fluids domain.  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