全文获取类型
收费全文 | 2171篇 |
免费 | 55篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 104篇 |
综合类 | 2篇 |
化学工业 | 729篇 |
金属工艺 | 86篇 |
机械仪表 | 55篇 |
建筑科学 | 44篇 |
矿业工程 | 3篇 |
能源动力 | 94篇 |
轻工业 | 227篇 |
水利工程 | 9篇 |
石油天然气 | 3篇 |
无线电 | 107篇 |
一般工业技术 | 450篇 |
冶金工业 | 56篇 |
原子能技术 | 72篇 |
自动化技术 | 193篇 |
出版年
2023年 | 10篇 |
2022年 | 33篇 |
2021年 | 45篇 |
2020年 | 25篇 |
2019年 | 41篇 |
2018年 | 41篇 |
2017年 | 33篇 |
2016年 | 50篇 |
2015年 | 43篇 |
2014年 | 62篇 |
2013年 | 121篇 |
2012年 | 103篇 |
2011年 | 135篇 |
2010年 | 117篇 |
2009年 | 126篇 |
2008年 | 127篇 |
2007年 | 121篇 |
2006年 | 96篇 |
2005年 | 75篇 |
2004年 | 87篇 |
2003年 | 72篇 |
2002年 | 61篇 |
2001年 | 44篇 |
2000年 | 43篇 |
1999年 | 37篇 |
1998年 | 59篇 |
1997年 | 36篇 |
1996年 | 33篇 |
1995年 | 25篇 |
1994年 | 29篇 |
1993年 | 21篇 |
1992年 | 27篇 |
1991年 | 27篇 |
1990年 | 16篇 |
1989年 | 16篇 |
1988年 | 9篇 |
1987年 | 22篇 |
1986年 | 17篇 |
1985年 | 16篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 20篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1979年 | 16篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1974年 | 4篇 |
1972年 | 3篇 |
排序方式: 共有2234条查询结果,搜索用时 15 毫秒
1.
Masahiro Asari Shinichi Iwamoto Tatsuki Okamoto Hiromasu Fukagawa 《Electrical Engineering in Japan》1992,112(1):25-38
The recent increase in the demand for power in urban areas has caused changes in the way power is supplied. Underground distribution systems have been introduced for convenience in urban areas and to prevent injuries in case of a crisis. As a result, many new types of power cables are being used. One type, XPLE cables (also called CV cables) have been rapidly taking the place of conventional cables such as OF or SL cables since the 1960s because of their relatively easy installation and maintainability. However, distribution cables used under severe environmental conditions deteriorate rapidly (due mainly to water treeing), and some cables experience insulation breakdown. Therefore, many diagnostic methods have been developed, though they have not been very effective. By combining methods, a high reliability can be achieved in comparison to the use of a single method. However, processing the data is difficult for on-site personnel, so many experts are required. But there is a lack of qualified experts, hence we have turned to the development of expert systems. 相似文献
2.
Masahiro Tatsumisago Tsutomu Minami Masami Tanaka 《Journal of the American Ceramic Society》1981,64(7):97-C-
A new technique combining a thermal-image furnace and a twin roller is described for quenching the melt to form glass. The technique was applied to the simple system Li2 O-SiO2 , since its fundamental parameters in the estimation of critical cooling rate are available. Glass flakes were obtained in the composition Li4 SiO4 , for which a very large critical cooling rate (∼109 K·s−1 ) was needed for glass formation. 相似文献
3.
Viscoelastic properties of poly(isoprene-b-styrene) in dioctylphthalate under steady shear flow were measured near the order—disorder transition temperature. In ordered states, first normal stress difference N1 is proportional to shear rate
at low
region, but becomes proportional to
at the high
region, similar to the N1 behaviour of polymer blends undergoing shear-induced homogenization. Because the existence of microdomains was confirmed at the high
region by the flow birefringence method, it is concluded that the above N1 behaviour is not caused by shear-induced homogenization, but is probably caused by the shear-induced alignment of the microdomain structure. 相似文献
4.
5.
Atsunori Matsuda Yugo Higashi Kiyoharu Tadanaga Masahiro Tatsumisago 《Journal of Materials Science》2006,41(24):8101-8108
SiO2–TiO2 spherical microparticles of about 0.7 μm in diameter were prepared by the sol–gel method. Anatase nanocrystals were formed in the microparticles and their specific surface area was increased after a hot-water treatment at 90 °C. From the changes in the concentration of I2 photocatalytically generated from KI aqueous solution, the activity of the SiO2–TiO2 microparticles was found to increase with increasing the hot-water treatment time. Particulate, thick films were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using the anatase nanocrystal-precipitated SiO2–TiO2 microparticles. The thickness of the electrophoretically deposited particulate film increased to be approximately 10 μm with an increase in applied voltage. The resultant thick film showed a high photocatalytic activity. 相似文献
6.
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
7.
Atsushi Kawase Momoko Hatanaka Naoya Matsuda Hiroaki Shimada Masahiro Iwaki 《International journal of molecular sciences》2022,23(15)
SLC25A39/40, involved in mitochondrial GSH (mGSH) import from the cytoplasm, is essential for protection against oxidative stress and mitochondrial dysfunction. We examined the effects of cholestasis, through bile duct ligation (BDL) and lipopolysaccharide (LPS)-induced inflammation in mice, on Slc25a39/40 expression. Additionally, we used human clear cell renal carcinoma (KMRC-1) cells to elucidate the mechanism of regulation of SLC25A39/40 expression in the kidneys after LPS treatment. BDL resulted in a decrease in Slc25a39 mRNA in the liver and a decrease in Slc25a39/40 mRNA and protein in the kidneys. Consequently, there was a significant decrease in mGSH levels in the kidneys of BDL mice compared with those in sham mice. LPS treatment resulted in increased Slc25a40 expression in the kidneys. In KMRC-1 cells, the combination treatment of LPS-RS or FPS-ZM1 with LPS suppressed the LPS-induced increase in SLC25A40, suggesting that SLC25A40 expression could be regulated by the signaling pathway via toll-like receptor 4 and the receptor for advanced glycation end products, respectively. Our findings contribute to understanding the role of mGSH in the maintenance of the mitochondrial redox state. To the best of our knowledge, this is the first study that demonstrates the changes in Slc25a39/40 expression in mice with cholestasis-associated renal injury and LPS-induced inflammation. 相似文献
8.
Mike Tien-Chien Lee Yu-Chin Hsu Ben Chen Masahiro Fujita 《Design Automation for Embedded Systems》1997,2(3-4):319-338
ATM switch, the core technology of an ATM networking system, is one of the major products in Fujitsu telecommunication business. However, current gate–level design methodology can no longer satisfy its stringent time–to–market requirement. It becomes necessary to exploit high–level methodology to specify and synthesize the design at an abstraction level higher than logic gates. This paper presents our prototyping experience on domain–specific high–level modeling and synthesis for Fujitsu ATM switch design. We propose a high–level design methodology using VHDL, where ATM switch architectural features are considered during behavior modeling, and a high–level synthesis compiler, MEBS, is prototyped to synthesize the behavior model down to a gate–level implementation. Since the specific ATM switch architecture is incorporated into both modeling and synthesis phases, a high–quality design is efficiently derived. The synthesis results shows that given the design constraints, the proposed high–level design methodology can produce a gate–level implementation by MEBS with about 15 percent area reduction in shorter design cycle when compared with manual design. 相似文献
9.
Thermoelectric materials have received much attention recently from the viewpoint of global environmental issues and effective utilization of energy resources. Especially those effective at relatively low temperature, such as below 100°C, which are usually abandoned without use, have become noteworthy recently. From this point of view, organic thermoelectric materials are most attractive, because they could be prepared at low cost and applied in various locations due to their flexibility. We have investigated the thermoelectric properties of organic conducting polymers such as polyaniline, polypyrrole, and polyphenylenevinylene, and succeeded in increasing the thermoelectric performance by selecting dopants, stretching conducting films, etc. Recently we have focused on new systems of organic–inorganic hybrid thermoelectric materials. Herein we present the preparation of a novel system of hybrids of polyaniline and bismuth(III) telluride nanoparticles, starting from bismuth(III) chloride and tetrachlorotellurium by using polyvinylpyrrolidone as a protecting reagent, as well as their thermoelectric properties. The hybrids prepared by this particular method showed much higher thermoelectric performance than the starting organic conducting polymer. 相似文献
10.