首页 | 官方网站   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   1898篇
  免费   137篇
  国内免费   235篇
工业技术   2270篇
  2024年   3篇
  2023年   17篇
  2022年   48篇
  2021年   49篇
  2020年   46篇
  2019年   30篇
  2018年   30篇
  2017年   57篇
  2016年   31篇
  2015年   61篇
  2014年   73篇
  2013年   76篇
  2012年   104篇
  2011年   136篇
  2010年   119篇
  2009年   87篇
  2008年   106篇
  2007年   99篇
  2006年   93篇
  2005年   84篇
  2004年   150篇
  2003年   82篇
  2002年   58篇
  2001年   55篇
  2000年   52篇
  1999年   67篇
  1998年   62篇
  1997年   34篇
  1996年   28篇
  1995年   20篇
  1994年   26篇
  1993年   61篇
  1992年   51篇
  1991年   46篇
  1990年   40篇
  1989年   35篇
  1988年   10篇
  1987年   11篇
  1986年   6篇
  1985年   13篇
  1984年   4篇
  1983年   3篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1959年   2篇
  1951年   1篇
排序方式: 共有2270条查询结果,搜索用时 234 毫秒
61.
对基于IP网络的门禁控制系统整体设计方案及原理进行了简要的分析,提出了在系统框架上将B/S模式和C/S模式相结合的设计思想,同时通过引入通信模块,在管理软件和控制器之间架起了专用的TCP通道,给出了一种实现TCP/IP通信的新方法,并加入门禁控制器主动通信方式,测试证明该通信平台运行稳定,能够提高门禁控制系统的工作效率。  相似文献   
62.
赵斌飞  刘磊 《计算机科学》2008,35(6):276-279
分析了现有的几种测试脚本生成技术,按照Mosley的同步数据驱动测试框架(CSDDT)框架设计并实现了一个针对面向对象程序的测试脚本生成器,通过实例验证了方法的可行性和工具的有效性,降低了产生测试脚本的工作量,对已知测试脚本产生过程中的弱点有很好的改进作用.生成脚本可以从单元测试开始应用,重用性良好,可同时测试多个类与方法,无须特定脚本开发语言.  相似文献   
63.
64.
An inexpensive, disposable, integrated, polymer-based cassette for loop-mediated isothermal amplification (LAMP) of target nucleic acids was designed, fabricated, and tested. The LAMP chamber was equipped with single-use, thermally actuated valves made with a composite consisting of a mixture of PDMS and expandable microspheres. The effect of the composite composition on its expansion was investigated, and the valve’s performance was evaluated. In its closed state, the valve can hold pressures as high as 200 kPa without any significant leakage. Both the LAMP chamber and the valves were actuated with thin film heaters. The utility of the cassette was demonstrated by carrying out LAMP of Escherichia coli DNA target and reverse transcribed loop meditated isothermal amplification (RT-LAMP) of RNA targets. The amplicons were detected in real time with a portable, compact detector. The system was capable of detecting as few as 10 target molecules per sample in well under 1 h. The portable, integrated cassette system described here is particularly suited for applications at the point of care and in resource-poor countries, where funds and trained personnel are in short supply.  相似文献   
65.
论述了航天用薄膜加热器的工作原理,推导和总结了同一加热区内三种不同串、并联关系的薄膜加热片单位面积阻值的通用计算公式。最后通过实例验证了该公式的正确性。对于具有复杂加热区的空间光学遥感器,依据该公式可以方便快捷地设计出各种串、并联关系的薄膜加热器。  相似文献   
66.
In this paper, we focus on the problem of adaptive stabilisation for a class of interconnected uncertain switched stochastic nonlinear systems. Classical adaptive and backstepping technique are employed for control synthesis. Instead of estimating the switching parameters directly, we design the adaptive controller based on the estimations of bounds on switching time-varying parameters. A smooth function is introduced to deal with the difficulties caused by unknown interactions and tuning function approach is used to circumvent the overparameter problem. It is shown that under the action of the proposed controller all the signals of the overall closed-loop systems are globally uniformly bounded in probability under arbitrary switching. Simulation results are presented to illustrate the effectiveness of the proposed approach.  相似文献   
67.
As a highly complex multi-input and multi-output system, blast furnace plays an important role in industrial development. Although much research has been done in the past few decades, there still exist many problems to be solved, such as the modeling problem. This paper adopts support vector regression (SVR) to construct the prediction model of blast furnace silicon content. To ensure a good generalization performance for the given datasets, it is important to select proper parameters for SVR. In view of this problem, a new particle swarm optimizer called DMS-PSO-CLS is presented to optimize the parameters of SVR. In DMS-PSO-CLS, a new cooperative learning strategy is hybridized with DMS-PSO, which makes particle information be used more effectively for generating better-quality solutions. DMS-PSO-CLS takes merits of the DMS-PSO and the cooperative learning strategy so that both the convergence speed and the convergence precision can be improved. Experimental results show that DMS-PSO-CLS can find the optimal parameters of SVR with high speed and the SVR model optimized by DMS-PSO-CLS can achieve a good regression precision on the predictive problem of blast furnace.  相似文献   
68.
This paper studies the leader‐following consensus problem for Lipschitz nonlinear multi‐agent systems using novel event‐triggered controllers. A distributed adaptive law is introduced for the event‐based control strategy design such that the proposed controllers are independent of system parameters and only use the relative states of neighboring agents, and hence are fully distributed. Due to the introduction of an event‐triggered control scheme, the controller of the agent is only triggered at it's own event times, and thus reduces the amount of communication between controller and actuator and lowers the frequency of controller updates in practice. Based on a quadratic Lyapunov function, the event condition which uses only neighbor information and local computation at trigger instants is established. Infinite triggers within a finite time are also verified to be impossible. The effectiveness of the theoretical results are illustrated through simulation examples.  相似文献   
69.
I. INTRODUCTION Along with the economical rapid development and the living standard unceasing enhancement, the consumer request to food quality in a new stair, food consumption pattern has assumed multiplex development tendency, food demand pattern transforms into "the multi- varieties, guarantees safety". Food no longer only is essential item which satisfies life needs; the consumer attention to food from the quantity moves towards the credit level, food security problem appears. How doe…  相似文献   
70.
本文心细介绍了基于无共享并行结构的并行嵌套环连接(PNLJ)算法的实现,旨在探索并行数据库系统的实现技术。  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-23

京公网安备 11010802026262号