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   1645篇
  免费   76篇
  国内免费   50篇
电工技术   69篇
技术理论   1篇
综合类   77篇
化学工业   184篇
金属工艺   100篇
机械仪表   184篇
建筑科学   169篇
矿业工程   31篇
能源动力   74篇
轻工业   127篇
水利工程   16篇
石油天然气   92篇
武器工业   3篇
无线电   66篇
一般工业技术   125篇
冶金工业   94篇
原子能技术   18篇
自动化技术   341篇
  2024年   2篇
  2023年   12篇
  2022年   18篇
  2021年   26篇
  2020年   25篇
  2019年   27篇
  2018年   22篇
  2017年   41篇
  2016年   36篇
  2015年   37篇
  2014年   78篇
  2013年   105篇
  2012年   90篇
  2011年   96篇
  2010年   88篇
  2009年   87篇
  2008年   72篇
  2007年   101篇
  2006年   96篇
  2005年   76篇
  2004年   106篇
  2003年   90篇
  2002年   56篇
  2001年   61篇
  2000年   44篇
  1999年   58篇
  1998年   38篇
  1997年   41篇
  1996年   36篇
  1995年   26篇
  1994年   13篇
  1993年   11篇
  1992年   8篇
  1991年   5篇
  1990年   8篇
  1989年   3篇
  1988年   4篇
  1987年   3篇
  1986年   4篇
  1985年   3篇
  1984年   5篇
  1982年   4篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1975年   1篇
  1964年   1篇
  1961年   1篇
排序方式: 共有1771条查询结果,搜索用时 31 毫秒
111.
本文对新一代可充碱锰电池即高功率可充碱锰电池(H—R—LR6型)的制作作了详细的研究,确定了电池结构、制造工艺,测试了产品性能,建立了产品的检验方法和检验标准。该电池标称电压1.5V,短路电流可达24.6A,1C率放电容量可放出约70%,循环寿命可达200周,明显优于传统粉环式结构的可充碱锰电池。  相似文献   
112.
We present a generalized let-polymorphic type inference algorithm, prove that any of its instances is sound and complete with respect to the Hindley/Milner let-polymorphic type system, and find a condition on two instance algorithms so that one algorithm should find type errors earlier than the other. By instantiating the generalized algorithm with different parameters, we can obtain not only the two opposite algorithms (the bottom-up standard algorithmW and the top-down algorithmM) but also other hybrid algorithms which are used in real compilers. Such instances’ soudness and completeness follow automatically, and their relative earliness in detecting type-errors is determined by checking a simple condition. The set of instances of the generalized algorithm is a superset of those used in the two most popular ML compilers: SML/NJ and OCaml. This work is supported by Creative Research Initiatives of the Korean Ministry of Science and Technology National Creative Research Initiative Center, http://ropas.kaist.ac.kr Work done while the third author was associated with Korea Advanced Institute of Science and Technology Hyunjun Eo: He is a Ph.D. candidate in the Department of Computer Science at KAIST (Korea Advanced Institute of Science and Technology). He recieved his bachelor’s degree and master’s degree in Computer Science from KAIST in 1996 and 1998, respectively. His research interest has been on static program analysis, fixpoint iteration algorithm and higher-order and typed languages. From fall 1998, he has been a research assistant of the National Creative Research Initiative Center for Research on Program Analysis System. He is currently working on developing a tool for automatic generation of program analyzer. Oukseh Lee: He is a Ph.D. candidate in the Department of Computer Science at KAIST (Korea Advanced Institute of Science and Technology). He received his bachelor’s and master’s degree in Computer Science from KAIST in 1995 and 1997, respectively. His research interest has been on static program analysis, type system, program language implementation, higher-order and typed languages, and program verification. From 1998, he has been a research assistant of the National Creative Research Initiative Center for Research on Program Analysis System. He is currently working on compile-time analyses and verification for the memory behavior of programs. Kwangkeun Yi, Ph.D.: His research interest has been on semanticbased program analysis and systems application of language technologies. After his Ph.D. from University of Illinois at Urbana-Champaign he joined the Software Principles Research Department at Bell Laboratories, where he worked on various static analysis approaches for higher-order and typed programming languages. For 1995 to 2003 he was a faculty member in the Department of Computer Science, Korea Advanced Institute of Science and Technology. Since fall 2003, he has been a faculty member in the School of Computer Science and Engineering, Seoul National University.  相似文献   
113.
We investigate how to take advantage of the particular features of the calculus of inductive constructions in the framework of hardware verification. First, we emphasize in a short case study the use of dependent types and of the constructive aspect of the logic for specifying and synthesizing combinatorial circuits. Then, co-inductive types are introduced to model the temporal aspects of sequential synchronous devices. Moore and Mealy automata are co-inductively axiomatized and are used to represent uniformly both the structures and the behaviors of the circuits. This leads to clear, general and elegant proof processes as is illustrated on the example of a realistic circuit: the ATM Switch Fabric. All the proofs are carried out using Coq.Accepted in revised form 29 February 2004 by C.B. Jones  相似文献   
114.
As one of the key problems of computer-aided conceptual design (CACD) for mechanism kinematic schemes, the effective establishment and management of knowledge base systems of kinematic behaviours and mechanisms is still troubled by information redundancy and unreasonable structure at present. Retrieval efficiency and solving intelligence of knowledge base reasoning systems on the basis of the knowledge classification method mentioned above have many unsatisfactory factors. So in this paper, firstly, data standardization technology and combined classification methods have been applied to carry out the classification of kinematic behaviours and mechanisms in the mapping field between the kinematic behaviour level and the mechanism level of conceptual design. Also, the principle of computer coding and storing have been built to give a fast and broad selection of mechanisms that meets the requirements of basic motion characters. Then on the basis of what was mentioned above, the heuristic matching propagation principle (HMPP) of kinematic behaviours and its truth table serve as a guide to perform mechanism type selections. The knowledge base automatic reasoning system of mechanism kinematic schemes based on HMPP is developed. By means of depth first search strategy, the motion requirements are matched against objects in the knowledge base along the orientation of function unit-mechanism IDfunction unit IDkinematic behaviour ID(output/input)motion type coding/ continuity coding/linearity coding/directionality coding at four different levels of abstraction. Top-down design process in this paper conforms to the law of innovative thinking for designers. If a direct match in a higher level was not discovered, then the design course will be transformed into the match at a low level automatically. According to the truth table of HMPP, once non-zero elements in kinematic behaviour ID (1 or 2) appear in the matching process, they will propagate until the solving process is over, and become one of the coding of the feasible solutions. The heuristic nature of HMPP presents a top-down solving method to decompose the complex requirements into several simpler ones. Different from traditional solving methods, the method presented in our research work has two advantages. Firstly it is easier to be operated and realized with a computer. Secondly, it is a creative process by nature. Finally, an application is given to indicate its practicability and effectiveness.  相似文献   
115.
I. J. Good 《TEST》1980,31(1):489-519
Summary A standard technique in subjective “Bayesian” methodology is for a subject (“you”) to make judgements of the probabilities that a physical probability lies in various intervals. In the hierarchical Bayesian technique you make probability judgements (of a higher type, order, level, or stage) concerning the judgements of lower type. The paper will outlinesome of the history of this hierarchical technique with emphasis on the contributions by I. J. Good because I have read every word written by him.  相似文献   
116.
For the study on the nonlinear dynamics of thin-film flow running down an inclined plane under the effect of an electrostatic field, the mechanism of solitary waves has been examined by using a global bifurcation theory. First, the existence of solitary waves has been chased by using an orbit homoclinic to a fixed point of saddle-focus type in a linearized third-order ordinary differential equation which resulted from the evolution equation in a steady moving frame. Then, the trajectories with several kinds of solitary waves have also been searched numerically for the nonlinear system. In addition, the behavior of these waves has been directly confirmed by integrating the initial-value problem. The slightly perturbed waves at the inception eventually evolve downstream into almost permanent pulse-like solitary waves through the processes of coalescence and repulsion of the triggered subharmonics. In the global aspects the flow system at a given Reynolds number becomes more unstable and chaotic than when there is no electrostatic force applied.  相似文献   
117.
118.
在研制开发豪华型250摩托车2V60M发动机过程中,解决了上箱体低压铸造过程中零件复杂、分型困难、浇道、 嵌件定位、型腔排气、模温控制、铸件缩补等技术难题,保证了铸件的优良品质。  相似文献   
119.
二进制代码的逆向工程是一个底层的技术,被应用于计算机安全、系统验证、加密解密等相关领域。在逆向工程中,C++的反编译技术是一个难点,尤其是其类型信息的恢复。该文提出了一种利用异常处理机制的类型恢复方法,该方法可以用来分析出每个函数的所有局部类变量,还能分析出这个类的构造函数和析构函数的地址。该方法在特定的环境下可以准确高效地解决C++反编译中的一个难点。  相似文献   
120.
本文面向维哈柯文自动选择显示字形研究,分析了新疆地区普遍使用的维吾尔、哈萨克文和柯尔克孜文变形显示的特点,简要介绍了最新Open Type 字体技术的结构与操作步骤,基于该字体技术设计了一种通用维哈柯文自动选形引擎,通过分析文字的连接类型,构建自动选形规则库,按照规则绑定字形标签,并应用Open Type 字体解释引擎按照字形标签完成字符替换与置位操作。并且在永中office 维哈柯文版本上实现了该自动选形引擎, 经实际应用测试证明,该字体引擎完全实现了维哈柯文变形显示的要求。  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