全文获取类型
收费全文 | 2254篇 |
免费 | 70篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 100篇 |
综合类 | 2篇 |
化学工业 | 734篇 |
金属工艺 | 102篇 |
机械仪表 | 59篇 |
建筑科学 | 46篇 |
矿业工程 | 3篇 |
能源动力 | 106篇 |
轻工业 | 252篇 |
水利工程 | 10篇 |
石油天然气 | 3篇 |
无线电 | 112篇 |
一般工业技术 | 476篇 |
冶金工业 | 67篇 |
原子能技术 | 67篇 |
自动化技术 | 194篇 |
出版年
2023年 | 8篇 |
2022年 | 33篇 |
2021年 | 46篇 |
2020年 | 25篇 |
2019年 | 41篇 |
2018年 | 44篇 |
2017年 | 36篇 |
2016年 | 50篇 |
2015年 | 45篇 |
2014年 | 63篇 |
2013年 | 125篇 |
2012年 | 108篇 |
2011年 | 138篇 |
2010年 | 124篇 |
2009年 | 130篇 |
2008年 | 133篇 |
2007年 | 124篇 |
2006年 | 105篇 |
2005年 | 79篇 |
2004年 | 88篇 |
2003年 | 73篇 |
2002年 | 63篇 |
2001年 | 43篇 |
2000年 | 47篇 |
1999年 | 42篇 |
1998年 | 59篇 |
1997年 | 41篇 |
1996年 | 37篇 |
1995年 | 27篇 |
1994年 | 28篇 |
1993年 | 28篇 |
1992年 | 27篇 |
1991年 | 30篇 |
1990年 | 17篇 |
1989年 | 16篇 |
1988年 | 9篇 |
1987年 | 22篇 |
1986年 | 23篇 |
1985年 | 20篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 19篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1979年 | 18篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1974年 | 5篇 |
1968年 | 3篇 |
排序方式: 共有2333条查询结果,搜索用时 15 毫秒
61.
Masahiro Ohshima 《Journal of Process Control》2003,13(7):599-6
‘Process control and systems engineering’ is not just a subject of study for controlling and designing ‘a plant’ and/or ‘a unit operation’. It also deals with any control and design problems related to physical and chemical phenomena occurring in short time-scale and at nano, meso as well as micro-scale levels. In materials processing, controlling the material structure is of primary importance for realizing high material performance and functions. The phenomena determining the material structure often involve phase separation and/or occur on the surface of the materials, at small level and in short time-scale. To control these phenomena, the current feedback design schemes, where controlled variables are measured by ‘externally equipped sensors’ and fed back to a ‘externally designed controller’, are no longer effective due to the shortness of time and smallness of spatial scales of the objects. Making reference to two novel polymer-processing processes, a micro-cellular polymeric foaming process and surface coating injection-molding process, we discuss how process control and process systems engineers can contribute to controlling the structure of materials. 相似文献
62.
A simultaneous detecting circuit system of centers and lengths of some lines in one dimension is presented applying an electronic circuit model of the nervous axon with respect to signal transmission. This model consists of series of one basic section, and has functions of Neuristor. The circuit system has a paralell processing function. It is constructed by three layers. In the first layer each visual signal of lines is changed to electric pulse signal. In the second layer edges of each line are detected, and in the third layer these detected signals are converted into voltages which correspond to lengths of the lines. These functions were confirmed experimentally using its hardware. 相似文献
63.
In this paper, we present Robot Entertainment as a new field of the entertainment industry using autonomous robots. For feasibility studies of Robot Entertainment, we have developed an autonomous quadruped robot, named MUTANT, as a pet-type robot. It has four legs, each of which has three degree-of-freedom, and a head which also has three degree-of-freedom. Micro camera, stereo microphone, touch sensors, and other sensor systems are coupled with newly developed behavior generation system, which has emotion module as its major components, and generates high complex and interactive behaviors. Agent architecture, real-world recognition technologies, software component technology, and some dedicated devices such as Micro Camera Unit, were developed and tested for this purpose. From the lessons learned from the development of MUTANT, we refined the design concept of MUTANT to derive requirements for a general architecture and a set of interfaces of robot systems for entertainment applications. Through these feasibility studies, we consider entertainment applications a significant target at this moment from both scientific and engineering points of view. 相似文献
64.
In this paper, we treat fuzzy linear programming problems with uncertain parameters whose ranges are specified as fuzzy polytopes.
The problem is formulated based on fractile optimization model using a necessity measure. It is shown that the problem can
be reduced to a semi-infinite linear programming problem and that a solution algorithm based on a relaxation procedure can
be applied. A simple numerical example is given to illustrate the solution procedure.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
65.
Takayuki Takei Hideki Nakahara Sadao Tanaka Hiroto Nishimata Masahiro Yoshida Koei Kawakami 《Journal of materials science. Materials in medicine》2013,24(10):2479-2487
We previously developed chitosan cryogels from chitosan-gluconic acid conjugate without using toxic additives for wound care. In this study, we improved physiological characteristics of the previous cryogels by incorporating poly(vinyl alcohol) that also form cryogels. Mechanical strength of the cryogels was more than two times higher than that of the previous cryogels. Furthermore, the incorporation of poly(vinyl alcohol) enhanced water retention and resistance to degradation of the gels by lysozyme. The cryogels retained the favorable biological properties of the previous cryogels that they accelerate infiltration of inflammatory cells into wound sites. Time period for repairing 50 % of initial area of partial-thickness skin wound treated with the cryogels (4.0 ± 1.1 days) was shorter than those with gauze (6.5 ± 0.3 days) or a commercial hydrogel dressing (5.7 ± 0.3 days). Finally, we confirmed that incorporation of basic fibroblast growth factor into the cryogels was effective to further accelerate wound healing (2.7 ± 1.0 days). These results demonstrate that the cryogels in this study are promising for wound care. 相似文献
66.
Masahiro Ishida Toru Nakura Takashi Kusaka Satoshi Komatsu Kunihiro Asada 《Journal of Electronic Testing》2016,32(3):257-271
This paper proposes a power integrity control technique for dynamically controlling power supply voltage fluctuations for a device under test (DUT), and demonstrates its effectiveness for eliminating the overkills/underkills due to the difference of power supply impedance between an automatic test equipment (ATE) and a practical operating environment of the DUT. The proposed method injects compensation currents into the power supply nodes on the ATE system in a feed-forward manner such that the ATE power supply waveform matches with the one on the customer’s operating environment of the DUT. A method for calculating the compensation current is also described. Experimental results show that the proposed method can emulate the power supply voltage waveform under a customer’s operating condition and eliminate 95 % of overkills/underkills in the maximum operating frequency testing with 105 real silicon devices. Limitations and applications of the proposed method are also discussed. 相似文献
67.
Nanoporous structure of the cell walls of polycarbonate foams 总被引:1,自引:0,他引:1
Using CO2 to prepare microcellular polycarbonate foams resulted in a pore diameter of 45 nm and a pore density of 108 cm?2 on the walls of microscale cells, which created nano/micro foams with an open cell structure. In this study, the craze nucleation theory and the bubble nucleation theory of foaming were combined to explain the mechanism of the foaming-induced nanopores (microvoids) on the cell walls. In the foaming process, the strain energy was developed in the cell walls by bubble nucleation and growth. With large strain energy, a nanoporous structure of the cell walls was formed by initiation of crazing. Because the foaming temperature affected the strain energy in the cell wall, the temperature became a key factor of forming microcellular structure as well as the nanopores on the cell walls. Our experimental results showed that the diameter and density of the nanopores were determined by the competitive movements between chain stretching and relaxation. Furthermore, certain solvents, such as acetone, were found to increase the nanopore density of the walls by exploiting the plasticization effect of the solvent on the reduction of surface tension and viscosity. 相似文献
68.
69.
Yoshihiro Sagisaka Itaru Ishibashi Tamotsu Nakamura Masahiro Sekizawa Yuh Sumioka Masahiro Kawano 《Journal of Materials Processing Technology》2012,212(9):1869-1874
The authors proposed double-layer-type environmentally friendly lubricants, which were composed of an undercoat, superior in adhering to a material, and an overcoat, superior in reducing the friction between the material and the die. The performance of these lubricants for cold forging was evaluated by the ring compression test, the combined forward rod-backward can extrusion-type friction test and the combined forward conical can-backward straight can extrusion-type friction test. The double-layer-type lubricants showed comparable friction characteristics and anti-pick-up properties to a conversion coating lubricant, when the film thickness and surface treatment before coating were improved. In a practical application by cold multistage forging, the double-layer-type lubricants showed a similar performance to a conversion coating lubricant. 相似文献
70.
In [N. Alon, M. Feldman, A.D. Procaccia, M. Tennenholtz, A note on competitive diffusion through social networks, Inform. Process. Lett. 110 (2010) 221–225], the authors introduced a game-theoretic model of diffusion process through a network. They showed a relation between the diameter of a given network and existence of pure Nash equilibria in the game. Theorem 1 of their paper says that a pure Nash equilibrium exists if the diameter is at most two. However, we have an example which does not admit a pure Nash equilibrium even if the diameter is two. Hence we correct the statement of Theorem 1 of their paper. 相似文献