全文获取类型
收费全文 | 433篇 |
免费 | 6篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 33篇 |
综合类 | 1篇 |
化学工业 | 96篇 |
金属工艺 | 51篇 |
机械仪表 | 13篇 |
建筑科学 | 18篇 |
能源动力 | 8篇 |
轻工业 | 24篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 32篇 |
一般工业技术 | 44篇 |
冶金工业 | 49篇 |
原子能技术 | 29篇 |
自动化技术 | 44篇 |
出版年
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 13篇 |
2013年 | 22篇 |
2012年 | 15篇 |
2011年 | 25篇 |
2010年 | 14篇 |
2009年 | 24篇 |
2008年 | 18篇 |
2007年 | 13篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 19篇 |
2000年 | 16篇 |
1999年 | 13篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有444条查询结果,搜索用时 31 毫秒
91.
92.
93.
A New Model for the Pollucite Thermal Expansion Mechanism 总被引:1,自引:0,他引:1
Hidehiko Kobayashi Ikuo Yanase Takashi Mitamura 《Journal of the American Ceramic Society》1997,80(8):2161-2164
The thermal expansion behavior of cubic pollucite (CsAlSi2 O6 ) in the temperature range 298 to 1473 K was investigated from the viewpoint of crystal structure, based on the model proposed in this study, with Rietveld analysis and high-temperature X-ray powder diffraction. Consequently, it has been found that the CsAlSi2 O6 structure provides an enlargement-contraction mechanism for two kinds of rings, each composed of six (Si,Al)O4 tetrahedra in a three-dimensional aluminosilicate framework, in the temperature range 298 to 673 K. 相似文献
94.
Ryutaro Kawamura Hisaya Hadama Ikuo Tokizawa 《Journal of Network and Systems Management》1995,3(3):243-264
This paper proposes an implementation scheme for the self-healing function in ATM (Asynchronous Transfer Mode) networks and assesses its performance in a developed experimental system. First, our proposed ATM self-healing scheme is described. This scheme realizes more rapid restoration of failed Virtual Paths than other self-healing algorithms, supports the node failure case, and minimizes the spare resources required. Next, an implementation scheme is proposed. We propose that the self-healing function can be implemented as a software process, and that OAM (Operation, Administration, and Maintenance) cells be utilized for fast message transmission. Next, results of a prototype system that we implemented on an ATM cross-connect system are discussed. The fundamental characteristics of restoration performance are measured using the experimental system. Based on these results, restoration characteristics of real world scale networks are estimated by computer simulations. The simulation results indicate that any-one link failure is completely restored within 2 seconds. 相似文献
95.
Miyahara Akira Mine Ikuo Watanabe Atsumi Sakou Eisaburo Nukiyama Makoto 《Power Delivery, IEEE Transactions on》1986,1(3):28-34
A communication system through distribution lines was developed for distribution automation. This system consists of a two level hierarchy system : a zero-phase-sequence carrier communication system through ungrounded 6kV distribution lines and an earth return communication system through grounded 100V/200V lines. In each system, transmission signals are generated by switching a passive element of small capacity between a line and the ground, and the signals are circulated through the line and the ground. By using this method, the influence of load impedance change and noises generated in loads is avoided sufficiently. Field tests were carried out at Ijiri Substation of the Kyushu Electric Power Co., Inc. for one year starting in September 1983. High reliability of the system was verified in terms of endurance in a severe environment and data transmission performance. 相似文献
96.
Summary A method for building small fast LALR parsers for regular right part grammars is given. No grammar transformation is required. No extra state of the LALR parser for the recognition of strings generated by a right part is required. At some reduce states the parser may refer to lookback states (states in which the parser may be restarted after the reduction). An optimizing algorithm to reduce these references is also given. 相似文献
97.
Intermetallic compounds formed during brazing of titanium with aluminium filler metals 总被引:5,自引:0,他引:5
The effect of aluminium filler metal composition on the formation of AI-Ti intermetallic compounds was investigated in brazed aluminium-to-titanium (Al/Ti) joints and titanium-totitanium (Ti/Ti) joints. The clearance filling ability was also studied. In Ti/Ti joints, the thickness of the intermetallic compound layer was strongly dependent on the aluminium filler metal composition, whereas the clearance filling ability was independent of the composition. The maximum intermetallic compound layer thickness was observed in 99.99% highly pure aluminium filler metal; therefore all additional elements reduced the layer thickness. Above all, the addition of 0.8% Si greatly reduced the thickness. After brazing at 680° C for 3 min, the intermetallic compound formed by Al-0 to 0.8% Si filler metal was found to be of type Al3Ti. Other compounds, of types Ti9Al23 and Ti7Al5Si12, were also found in joints brazed by Al-3 to 10% Si filler metals. AI-0.8% Si filler metals maintained a higher joint strength than pure aluminium filler metal under brazing conditions of high temperature and long heating time. In Al/Ti joints, AI-Cu-Sn and AI-Cu-Ag filler metal mainly formed Al3Ti, and Al-10Si-Mg filler metal mainly formed Ti7Al5Si12 at the brazed interface of the titanium side after brazing at 600 to 620° C. 相似文献
98.
99.
This paper presents an algorithm for the automatic generation of solid objects from three-dimensional wire-frame data. In this work, as we mainly use topological information of wire-frame data, we can achieve high-speed execution and adapt this algorithm to free-from surfaces. We present the conversion algorithm and show several experimental results. 相似文献
100.
As operation frequencies of the printed circuit boards (PCBs) increase in keeping with VLSI frequencies in the GHz domain, two independent serious problems occur in the PCB design. One is waveform distortion problem, or signal integrity (SI) degradation problem, in PCB traces. And the other is power-supply drop problem, or power integrity (PI) degradation problem, in PCB power planes. Those problems are barely able to be overcome on case-by-case empirical designs conventionally. In this paper we newly propose a design approach for each problem, both of which are based on the genetic algorithm. And we obtained improvement ratios of more than double compared with the both conventional designs for SI and PI degradations, respectively. 相似文献