全文获取类型
收费全文 | 4155篇 |
免费 | 102篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 38篇 |
综合类 | 3篇 |
化学工业 | 787篇 |
金属工艺 | 98篇 |
机械仪表 | 89篇 |
建筑科学 | 147篇 |
矿业工程 | 10篇 |
能源动力 | 56篇 |
轻工业 | 441篇 |
水利工程 | 33篇 |
石油天然气 | 5篇 |
无线电 | 347篇 |
一般工业技术 | 477篇 |
冶金工业 | 1292篇 |
原子能技术 | 20篇 |
自动化技术 | 416篇 |
出版年
2022年 | 93篇 |
2021年 | 100篇 |
2020年 | 45篇 |
2019年 | 69篇 |
2018年 | 54篇 |
2017年 | 61篇 |
2016年 | 72篇 |
2015年 | 60篇 |
2014年 | 71篇 |
2013年 | 165篇 |
2012年 | 110篇 |
2011年 | 134篇 |
2010年 | 115篇 |
2009年 | 116篇 |
2008年 | 132篇 |
2007年 | 139篇 |
2006年 | 125篇 |
2005年 | 108篇 |
2004年 | 89篇 |
2003年 | 97篇 |
2002年 | 108篇 |
2001年 | 80篇 |
2000年 | 75篇 |
1999年 | 100篇 |
1998年 | 288篇 |
1997年 | 179篇 |
1996年 | 137篇 |
1995年 | 96篇 |
1994年 | 97篇 |
1993年 | 83篇 |
1992年 | 54篇 |
1991年 | 36篇 |
1990年 | 71篇 |
1989年 | 71篇 |
1988年 | 62篇 |
1987年 | 53篇 |
1986年 | 48篇 |
1985年 | 50篇 |
1984年 | 51篇 |
1983年 | 43篇 |
1982年 | 40篇 |
1981年 | 37篇 |
1980年 | 34篇 |
1979年 | 29篇 |
1978年 | 24篇 |
1977年 | 45篇 |
1976年 | 72篇 |
1974年 | 29篇 |
1973年 | 24篇 |
1971年 | 23篇 |
排序方式: 共有4259条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
John E. Beard
Malcolm E. Wright
Michael MailanderMark Miller
《Mechanism and Machine Theory》1992,27(6):635-644The design of a specialized agricultural harvesting machine required the use of a path generation mechanism that was compact, accurate, inexpensive to manufacture and difficult attempts involved the use of a cam and follower, but they were expensive to manufacture and difficult to operate. This paper discusses an alternative method of using a coupled, open loop, two-link mechanism to generate a polygon-like closed path (pseudo-polygon) with an integer number of curved sides and apexes. A complete development of the path and path curvaturei equations are presented. The influence of the design variables on the coupler shape (flatness of each side) is shown in equation and design chart form. An example of a successful application of this design method applied to a plant cutting mechanism is presented. 相似文献
15.
16.
The Mono Mac 6 (MM6) human monocytic cell line was evaluated with the established J774 murine macrophage cell line to ascertain its effectiveness in determining the intracellular activities of antimycobacterial drugs. Cells were infected with Mycobacterium tuberculosis H37Ra and treated with drug concentrations corresponding to the MICs, as well as to threefold higher than and threefold less than the MICs. Changes in CFU were compared after 7 days to determine significant differences between treated and nontreated groups. The results suggest that MM6 will make a useful model for testing the intracellular activities of antituberculosis drugs. 相似文献
17.
18.
A discrete-time, model-based output feedback control structure for nonlinear processes is developed in the present work. The structure makes use of a closed-loop observer, while at the same time it guarantees that the overall feedback controller possesses integral action. An algebraic transformation is applied on the observer states to insure that the input/output gain of the observer matches the model upon which the static state feedback control law is based. The resulting control algorithm is a two-degree-of-freedom control law, in the sense that the output and the set point are processed in different ways. The control structure is shown not only to have the same properties as the standard model-state feedback structure, but also that it emerges from a model algorithmic control framework. Finally, a simulation example using an exothermic CSTR operating at an open-loop unstable steady state is used to evaluate the closed-loop performance of the proposed method. 相似文献
19.
Les Hatton Andy Wright Stuart Smith Gregg Parkes Paddy Bennett Robert Laws 《Software》1988,18(4):301-329
The portability of software has become a major commercial issue in recent times. Such portability does not come easily, as few if any computer languages are really portable in practice. An additional complicating factor, especially in the commercial environment, is that the resulting software must be efficient. This paper describes the design and successful implementation of a 500,000+ line portable FORTRAN 77 package for the processing of seismic data. The package exhibits demonstrably high efficiency on a wide variety of machines from minicomputers to the largest supercomputers. Experiences gained during this exercise throw much light on the integration of the various thought processes which occur during the software engineering cycle, especially the notion of locality. 相似文献
20.
Royzman Edward B.; Cassidy Kimberly Wright; Baron Jonathan 《Canadian Metallurgical Quarterly》2003,7(1):38
This article reviews the evidence and theory pertaining to a form of perspective-taking failure--a difficulty in setting aside the privileged information that one knows to be unavailable to another party. The authors argue that this bias (epistemic egocentrism, or EE) is a general feature of human cognition and has been tapped by 2 independent and largely uncommunicating research traditions: the theory-of-mind tradition in developmental psychology and, with more sensitive probes, the "heuristics and biases" tradition in the psychology of human judgment. This article sets the stage for facilitating communication between these traditions as well as for the recognition of EE's breadth and potential interdisciplinary significance. The authors propose a life-span account and a tentative taxonomy of EE; and they highlight the interdisciplinary significance of EE by discussing its implications for normative ethics. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献