全文获取类型
收费全文 | 314篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 11篇 |
化学工业 | 47篇 |
金属工艺 | 23篇 |
机械仪表 | 15篇 |
能源动力 | 13篇 |
轻工业 | 20篇 |
无线电 | 41篇 |
一般工业技术 | 45篇 |
冶金工业 | 75篇 |
原子能技术 | 8篇 |
自动化技术 | 25篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 21篇 |
2012年 | 13篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 16篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 11篇 |
2002年 | 3篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 30篇 |
1997年 | 24篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有323条查询结果,搜索用时 15 毫秒
51.
Takashi Shinmoto Chiaki Kimura Ken Yamamoto Susumu Umeda 《Electrical Engineering in Japan》1996,116(5):75-84
The method for measuring insulation resistance by superimposing the dc voltage has potential for detecting the deterioration of cable insulations. The deterioration of cable insulations can be detected by measuring current which flows through a grounded shielding wire. However, the earth current also flows from the cable sheath into the grounding wire as noise. Thus, to assess the deterioration properly, it is necessary to separate the earth current from the total current. On the other hand, to improve detection sensitivity, it is desirable to superimpose the highest possible dc voltage. In this case, provision must be made so that there are no adverse effects on the GPT. The authors, placing special emphasis on the method of measuring high insulation resistance by configuring the bridge, have conducted an investigation on how to detect the insulation deterioration with high accuracy and sensitivity without impairing the functions of the GPT. The following issues were investigated and the results are reported in this paper: (1) It is possible to measure insulation resistance as high as 100,000 MΩ by superimposing 50-V dc through the GPT after cancelling the earth-current and by configuring a bridge for determining insulation resistance from voltage ratio. (2) Even if 50-V dc is superimposed through the GPT, it is possible to prevent the magnetic saturation of GPT if the current injected by such superimposition is limited (i.e., below max. 5 mA). (3) In lieu of a variable resistor, a variable dc voltage supply is employed in the bridge. The variable dc voltage supply requires no mechanically driven part, thus making it possible to realize a fully automatic monitoring system. 相似文献
52.
53.
Integration of well maintained application programs for process design is attempted using an in-house Data Base Management System. The main reason for taking the present approach is to keep the reliability of the existing application programs and to minimize revision work. Through the authors' experience described in this paper, it was found that the proposed way of integration by means of DBMS is to be recommended for these purposes when the number of application programs is small. 相似文献
54.
A method for cause and effect analysis of chemical processing systems has been developed on the concept of a signed directed graph. The signed directed graph, called a “model graph,” is used for representing cause and effect relationships among process variables in a system, and a “Pattern” on the graph is introduced to represent a state of the system, which is specified by “0” for normal state, “ + ” and “ ? ” for larger and smaller deviation from the normal state, respectively. For a given model graph and pattern on it, the cause of state changes and the manner of their propagation are easily found out by the present approach, which is mainly based on the depth-first search algorithm developed by Tarjan. As an illustrative example, a propane vaporizer has been taken to show the usefulness of the present approach. 相似文献
55.
56.
57.
58.
A thermodynamic approach to the synthesis of heat integration systems in chemical processes 总被引:1,自引:0,他引:1
Starting with no heat integration, from initial structure for a chemical processing system, a series of modified systems with improved heat utilization can be evolutionally developed by a computer aided method, on the thermodynamic available energy concept. An illustrative example shows that processing systems with high degree of efficient energy utilization have been generated. 相似文献
59.
A.C. Shaw has introduced the concept of the flow expression which is an extended regular expression and state several results with some conjectures. His conjecture that the flow expressions define context-sensitive languages has been answered negatively by two of the present authors, that is, the flow languages are recursively enumerable.In this paper, it is shown that flow languages for some restricted class of flow expressions are equivalent to Petri net languages. Some related decision problems for flow expressions are also discussed. 相似文献
60.
The effects of phase jitter and cycle slipping of the recovered carrier upon unique word (UW) missed detection in QPSK systems are investigated. Schrempp et al. have already presented the relationship between the UW missed detection probability (UWMP) and the bit error probability, which is simple and useful as long as the phase reference is noiseless. However, when the authors recently made some theoretical and experimental assessments of UW missed detection, they found that the above disturbances of the recovered carrier significantly affected the UW missed detection performance. Specifically, the actual UWMP was often worse than that predicted hy Schrempp et al. In fact, a bottoming effect takes place in the UWMP versus UW length characteristic. In this paper, after obtaining the conditional symbol and bit error probabilities for the recovered carrier with some phase error, we discuss the nature of phase fluctuation and cycle slipping for the recovered carrier. Consequently, we derive general expressions for the UWMP in both CPSK and DCPSK transmissions. The UWMP's are numerically calculated, and are then compared to our experimental data. 相似文献