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   3962篇
  免费   117篇
  国内免费   75篇
电工技术   99篇
技术理论   2篇
综合类   165篇
化学工业   465篇
金属工艺   243篇
机械仪表   360篇
建筑科学   577篇
矿业工程   249篇
能源动力   256篇
轻工业   152篇
水利工程   24篇
石油天然气   110篇
武器工业   14篇
无线电   137篇
一般工业技术   257篇
冶金工业   151篇
原子能技术   42篇
自动化技术   851篇
  2024年   7篇
  2023年   71篇
  2022年   102篇
  2021年   140篇
  2020年   124篇
  2019年   86篇
  2018年   62篇
  2017年   69篇
  2016年   112篇
  2015年   110篇
  2014年   232篇
  2013年   178篇
  2012年   265篇
  2011年   300篇
  2010年   186篇
  2009年   197篇
  2008年   174篇
  2007年   233篇
  2006年   219篇
  2005年   189篇
  2004年   159篇
  2003年   145篇
  2002年   129篇
  2001年   85篇
  2000年   88篇
  1999年   105篇
  1998年   80篇
  1997年   61篇
  1996年   42篇
  1995年   42篇
  1994年   30篇
  1993年   25篇
  1992年   20篇
  1991年   12篇
  1990年   6篇
  1989年   5篇
  1988年   8篇
  1987年   5篇
  1986年   9篇
  1985年   4篇
  1984年   6篇
  1983年   6篇
  1982年   9篇
  1981年   5篇
  1980年   2篇
  1979年   4篇
  1978年   2篇
  1963年   1篇
  1958年   1篇
  1954年   1篇
排序方式: 共有4154条查询结果,搜索用时 15 毫秒
101.
周征  陈瑞 《自动化仪表》2010,31(4):63-64,67
传感器输出信号的数字采集是工业检测系统数字化的关键技术,通过对各种传感器的分析和研究,采用能适应0~100mV宽动态模拟输入信号范围、24位显示分辨率的数字采集技术,研制出电压输出型传感器高精度数字转换模块.该模块具有功耗低、体积小、可靠性高、使用安装方便的特点,解决了工业现场各种类型传感器输出信号的数字量转换问题,它为企业新产品研发和传统设备数字化改造提供了前端数字信息采集的硬件支持.  相似文献   
102.
This paper illustrates the benefits of a multivariable linearizing control approach applied to an industrial crystallization process. This relevant approach proposes a setpoint tracking for the crystal mass/concentration couple. In this purpose, a model dedicated to last stage crystallization is designed, without consideration of crystal size distribution. The controlled variables, unavailable, are obtained using an extended Luenberger observer. The observer is validated on industrial data and shows good performance in both convergence rate and accuracy. The performance of the proposed linearizing strategy, which application to cane sugar crystallization constitutes a real novelty, is tested via simulation. The good performance in setpoint tracking, even in presence of noise, disturbances and modeling error, allows to consider a significant improvement of the global productivity.  相似文献   
103.
为了实现串口与工业以太网之间数据的传输,采用嵌入式Intemet技术,以高性能、低功耗32位RISC结构的ARM9微处理器S3C2410和嵌入式实时操作系统Linux为核心,设计了智能工业以太网网关,并基于ARM-Linux平台,在网关中构建了嵌入式Web服务器.最后,将特定工业监控设备串口通信协议集成到网关中.经测试和实践表明,该网关性能稳定,可以提供Web服务,为数据采集和工业控制系统的异构集成提供了有效的解决途径.  相似文献   
104.
Identifying the Cost-To-Serve (CTS) of customers is one of the most challenging problems in Supply Chain Management because of the diversity in their business activities. For the particular case of the industrial gas business, we are interested in predicting the cost to deliver bulk (liquefied) gas to new customers using a multifactor linear regression model. Developing a single model, i.e. analyzing the observations all at once, produces poor prediction results. Therefore prior to the regression analysis, a new supervised learning technique is used to group customers who are similar in some sense. Classes of customers are represented by hyper-boxes and a linear regression model is subsequently built within each class. The combination of data classification and regression is proven to increase the accuracy of the prediction.Two Mixed-Integer-Linear Programming (MILP) models are developed for data classification purposes. Although we are dealing with a supervised learning method, classes are not predefined in our case. Rather, we input a continuous “classification” attribute that is optimally discretized by the MILP’s in order to minimize the number of misclassifications. Therefore our data classification model offers a broader range of applications. A number of illustrative examples are used to prove the effectiveness of the proposed approach.  相似文献   
105.
In the recent years, industrial clusters have received considerable attention from economists and industrial analysts, because they are seen as the main reason for economic growth and success of certain economic region. This study systematically reviews past researches of industrial cluster. The purpose of this paper is to contribute to the understanding of this issue regarding the driving forces for the growth of industrial cluster and find out the priority among these cluster policies. Taiwan HsinChu Science Park is a prime example for this paper, and its connection with the innovative participators. We begin with an examination of the literature on cluster about its driving forces and policies upon which we propose a conceptual framework. In doing so, we explore the cluster-based industrial system. Then this research adopts the Fuzzy Analytic Hierarchy Process as the analytical tool. The Fuzzy Analytic Hierarchy Process method is used to determine the weightings for evaluation dimension among decision makers. From our research results, the Factor Conditions is the most important driving force for advancing the industrial cluster performance. Moreover, the promotion of international linkages policy and broader framework policies rank the first two priorities for cluster policy. Overall, this paper concludes with some simulations of cluster policy alternatives confronting the industry and the Taiwanese government.  相似文献   
106.
Load restraint systems in automobile transport utilise tie-down lashings placed over the car’s tyres, which are tensioned manually by the operator using a ratchet assembly. This process has been identified as a significant manual handling injury risk. The aim of this study was to gain insight on the current practices associated with tie-down lashings operation, and identify the gaps between current and optimal practice. We approached this with qualitative and quantitative assessments and one numerical simulation to establish: (i) insight into the factors involved in ratcheting; (ii) the required tension to hold the car on the trailer; and (iii) the tension achieved by drivers in practice and associated joint loads. We identified that the method recommended to the drivers was not used in practice. Drivers instead tensioned the straps to the maximum of their capability, leading to over-tensioning and mechanical overload at the shoulder and elbow. We identified the postures and strategies that resulted in the lowest loads on the upper body during ratcheting (using both hands and performing the task with their full body). This research marks the first step towards the development of a training programme aiming at changing practice to reduce injury risks associated with the operation of tie-down lashings in the automobile transport industry.

Practitioner Summary: The study investigated current practice associated with the operation of tie-down lashings through qualitative (interviews) and quantitative (biomechanical analysis) methods. Operators tended to systematically over-tension the lashings and consequently overexert, increasing injury risks.  相似文献   

107.
基于攻击图的工控系统脆弱性量化方法   总被引:2,自引:0,他引:2  
提出了一种基于攻击图的工控系统脆弱性量化研究方法. 从工控系统中存在的漏洞利用难度和漏洞危害性两个维度出发, 同时结合具体的工业系统中有关防御强度、攻击强度、物理损失、信息损失等方面, 提出了一系列的脆弱性量化指标, 制定了比较全面的等级划分标准. 之后将量化指标与攻击图相结合, 利用攻击过程中每一步的原子攻击期望来对可能存在的所有攻击路径进行脆弱性分析. 最后以典型的锅炉控制系统作为实验背景进行了案例分析. 实验结果表明, 该方法能够较全面地分析工控系统中潜在的隐患威胁, 科学合理地评估各条攻击路径的脆弱性, 由此得到总攻击期望最大的攻击路径.  相似文献   
108.
In this contribution, we obtain a nonlinear controller for a class of nonlinear time delay systems, by using the inverse optimality approach. We avoid the solution of the Hamilton Jacobi Bellman type equation and the determination of the Bellman's functional by extending the inverse optimality approach for delay free nonlinear systems to time delay nonlinear systems. This is achieved by combining the Control Lyapunov Function framework and Lyapunov-Krasovskii functionals of complete type. Explicit formulas for an optimal control are obtained. The efficiency of the proposed method is illustrated via experimental results applied to a dehydration process whose model includes a delayed state linear part and a delayed nonlinear part. To give evidence of the good performance of the proposed control law, experimental comparison against an industrial Proportional Integral Derivative controller and optimal linear controller. Additionally experimental robustness tests are presented.  相似文献   
109.
陈庄  黄勇  邹航 《计算机科学》2013,40(Z6):340-343
目前工业控制系统(Industrial Control System,ICS)广泛应用于电力、水利、交通运输、大型制造行业以及国家基础公共设施,已经成为国家安全战略的重要部分。 传统的信息安全防护技术(如防火墙技术、入侵检测技术等)因其技术原理和适用协议的差异,使工业控制系统不能取得很好的防范效果。为了有效地提高ICS的安全防护能力,该文针对ICS的数据特点以及协议特点设计了一款ICS信息安全审计系统,该审计系统主要由数据采集模块、内容检测模块、异常行为判断模块、行为处理模块、审计响应模块等组成。实验结果表明,本系统能够对ICS进行全方位的安全审计,能够极大程度地提高ICS的安全防护能力。  相似文献   
110.
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