全文获取类型
收费全文 | 1005篇 |
免费 | 29篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 74篇 |
综合类 | 2篇 |
化学工业 | 312篇 |
金属工艺 | 31篇 |
机械仪表 | 21篇 |
建筑科学 | 22篇 |
能源动力 | 53篇 |
轻工业 | 95篇 |
石油天然气 | 1篇 |
无线电 | 48篇 |
一般工业技术 | 179篇 |
冶金工业 | 64篇 |
原子能技术 | 47篇 |
自动化技术 | 88篇 |
出版年
2023年 | 10篇 |
2022年 | 15篇 |
2021年 | 31篇 |
2020年 | 19篇 |
2019年 | 15篇 |
2018年 | 19篇 |
2017年 | 18篇 |
2016年 | 34篇 |
2015年 | 21篇 |
2014年 | 37篇 |
2013年 | 73篇 |
2012年 | 52篇 |
2011年 | 71篇 |
2010年 | 46篇 |
2009年 | 44篇 |
2008年 | 53篇 |
2007年 | 50篇 |
2006年 | 50篇 |
2005年 | 33篇 |
2004年 | 36篇 |
2003年 | 30篇 |
2002年 | 18篇 |
2001年 | 18篇 |
2000年 | 19篇 |
1999年 | 18篇 |
1998年 | 24篇 |
1997年 | 21篇 |
1996年 | 15篇 |
1995年 | 16篇 |
1994年 | 14篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1966年 | 1篇 |
1964年 | 2篇 |
排序方式: 共有1037条查询结果,搜索用时 10 毫秒
91.
Ganglioside GT1b and, to a lesser extent, GD3, enhanced phosphorylation of a 36 kDa protein (the substrate of protein kinase
C) in the particulate fraction from bovine mammary gland. Sialic acids, asialogangliosides, and GM3 were without effect, and
GD1a conversely inhibited phosphorylation of the 36 kDa protein. The enhanced phosphorylation by GT1b required the simultaneous
presence of phosphatidylserine (PS) and Ca2+. The 36 kDa protein reacted with anti-annexin I in Western blot analysis. Addition of purified annexin I to the reaction
mixture containing the particulate fraction increased the extent of phosphorylated 36 kDa protein, and the phosphorylation
was further enhanced by GT1b. The enhanced phosphorylation of annexin I by GT1b was also dependent on PS and Ca2+. When annexin I was phosphorylated by purified protein kinase C, GT1b inhibited the annexin I phosphorylation. Addition of
epidermal growth factor or insulin to the particulate fraction had little effect on the enhancement. These results suggest
that an enzyme or enzymes other than protein kinase C, epidermal growth factor receptor kinase, or insulin receptor kinase
is responsible for the GT1b- and GD3-enhanced phosphorylation of annexin I in the presence of PS and Ca2+. 相似文献
92.
Savary Pierre Nakaoka Mutsuo Maruhashi Toru 《Industrial Electronics, IEEE Transactions on》1987,(2):247-256
The authors introduce a new configuration of resonant-type high-frequency inverter having inherent fast control response of the output power and variable-voltage variable-frequency (VVVF) capability. The circuit is composed of a parallel combination of two series-resonant inverters with common input and output terminals. Both inverter units are operated at synchronous frequency and with an adjustable phase difference from 0° to 180°, allowing control of the output power from full to null power, respectively. Operation of this inverter is explained and computer-simulated operating waveforms and characteristic curves are shown in terms of normalized control variables and circuit parameters. A prototype inverter using Power MOSFET modules has been originally tested with a high-frequency induction heating and melting load to demonstrate experimentally the proposed control principle and the steady-state inverter performances under parallel tuned load conditions. 相似文献
93.
Toru Obara Takeru Koga Terumitsu Miura Hiroshi Sekimoto 《Progress in Nuclear Energy》2008,50(2-6):556-559
Fundamental experiments were performed to determine the adhesion characteristics of polonium to different metals and to develop a filter for polonium evaporated from neutron-irradiated LBE. The results of the first experiments suggested that adhesion characteristics are almost the same for stainless steel and nickel metal. The results of the preliminary experiments for a polonium filter suggested that stainless steel mesh with thin wires could effectively collect polonium evaporated from neutron-irradiated LBE. In the experiments, stainless steel wire mesh was used, but from the results of adhesion experiment, it is expected that the same effect can be obtained with wire mesh made of other kinds of metal. 相似文献
94.
Toru Ikegami Tomotake Morita Shunichi Nakayama Hideyuki Negishi Dai Kitamoto Keiji Sakaki Yasunori Oumi Tsuneji Sano Kenji Haraya Hiroshi Yanagishita 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(8):1172-1177
BACKGROUND: Pervaporation employing ethanol‐permselective silicalite membranes as an alternative to distillation is a promising approach for refining low‐concentration bioethanol solutions. However, to make the separation process practicable, it is extremely important to avoid the problems caused by the adsorption of succinate on the membrane during the separation process. In this work, the pervaporation of an ethanol fermentation broth without succinate was investigated, as well as the influence of several fermentation broth nutrient components. RESULTS: Candida krusei IA‐1 produces an extremely low level of succinate. The decrease in permeate ethanol concentration through a silicone rubber‐coated silicalite membrane during the separation of low‐succinate C. krusei IA‐1 fermentation broth was significantly improved when compared with that obtained using Saccharomyces cerevisiae broth. By treating the fermentation broth with activated carbon, bioethanol was concentrated as efficiently as with binary mixtures of ethanol/water. The total flux was improved upto 56% of that obtained from the separation of binary mixtures, compared with 43% before the addition of activated carbon. Nutrients such as peptone, yeast extract and corn steep liquor had a negative effect on pervaporation, but this response was distinct from that caused by succinate. CONCLUSION: For consistent separation of bioethanol from C. krusei IA‐1 fermentation broth by pervaporation, it is useful to treat the low nutrient broth with activated carbon. To further improve pervaporation performance, it will be necessary to suppress the accumulation of glycerol. Copyright © 2009 Society of Chemical Industry 相似文献
95.
Lead-bismuth eutectic (LBE) has good characteristics for the coolant and/or target of various nuclear systems, but it also has a problem of polonium contamination. In the study, baking experiment was performed to remove polonium contamination on type 316 stainless steel plate that was originated from neutron irradiated LBE. The contaminated type 316 stainless steel plate was baked in a vacuum condition at various temperatures from 200°C to 600°C. In the previous preliminary study, the effect of short time baking was investigated. In the study, the effect of long time baking was investigated. The detail of the experimental method was also described. The result of long time baking experiment showed that the baking method was effective for removal of polonium from stainless steel surface contaminated by neutron irradiated LBE, if the baking was performed at 500°C and higher in a vacuum condition. The obtained result was consistent to the previous preliminary study. 相似文献
96.
Yasutaka Hayamizu Kyoji Yamamoto Shinichiro Yanase Toru Hyakutake Toru Shinohara Shinichi Morita 《热科学学报(英文版)》2008,17(3):193-198
An objective of the present paper is to experimentally clarify the torsion effect on the flow in helical circular pipes. We have made six helical circular pipes having different pitches and common non-dimensional curvature δ of about 0.1. The torsion parameter β0, which is defined by β0 = τ/(2δ)1/2 with non-dimensional torsion r, are taken to be 0.02, 0.45, 0.69, 1.01, 1.38 and 1.89 covering from small to very large pitch. The velocity distributions and the turbulence of the flow are measured using an X-type hot-wire anemometer in the range of the Reynolds number from 200 to 20000. The results obtained are summarized as follows: The mean secondary flow pattern in a cross section of the pipe changes from an ordinary twin-vortex type as is seen in a curved pipe without torsion (toroidal pipe) to a single vortex type after one of the twin-vortex gradually disappears as β0 increases. The circulation direction of the single vortex is the same as the direction of torsion of the pipe. The mean velocity distribution of the axial flow is similar to that of the toroidal pipe at small β0, but changes its shape as β0 increases, and attains the shape similar to that in a straight circular pipe when ,β0 = 1.89. It is also found that the critical Reynolds number, at which the flow shows a marginal behavior to turbulence, decreases as ,β0 increases for small ,β0, and then increases after taking a minimum at ,β0 ≈ 1.4 as ,β0 increases. The minimum of the critical Reynolds number experimentally obtained is about 400 at ,β0 ≈ 1.4. 相似文献
97.
Evert‐Jan van Donkelaar Juergen Schultze Toru Shibuya Yutaka Konai Mitsuharu Miyazaki 《Journal of the Society for Information Display》2002,10(3):223-229
In 1998, Toyo Gosei Co. published a paper on the development of a new water‐soluble photopolymer of high sensitivity, PVA‐ARBB. In close co‐operation with LG. Philips Displays, the new material was further developed to be applicable in patterning the phosphor layer of a CRT screen. The new material shows about 3 times higher light sensitivity, gives 4–5% higher luminance, has no dark reaction, and is chromium‐free. It is the first chromium‐free photoresist used for phosphor patterning in CRT mass production. A comparison is presented between the conventional resist and the new resist. A survey is given of the most important process conditions. 相似文献
98.
Further improvement of graduate school education in nuclear field is one of the important issues in universities in nuclear field. The COE-INES program has performed international cooperative activities for graduate school education with foreign universities in nuclear field. There are a lot of possibilities in international cooperation with foreign universities for graduate school education. The use of Internet can be a strong tool for the activities. 相似文献
99.
Raymond L.D. Whitby Takahiro Fukuda Toru Maekawa Stuart L. James Sergey V. Mikhalovsky 《Carbon》2008,46(6):949-956
The fabrication of buckypaper from unfunctionalised multi-walled carbon nanotubes (MWCNTs) without the aid of surfactants or surface modification techniques is accomplished through a novel and quick frit compression method. The dimensions can be controlled through the size of the syringe housing and the through the mass of carbon nanotubes added. Their thicknesses are typically much larger than surfactant-cast buckypaper and range from 120 μm up to 650 μm; buckypaper with thicknesses larger than 500 μm we call buckydiscs. Buckypaper and buckydiscs are mechanically robust to handle, flexible, stable in solvents and possess larger porosities than Triton-X100 cast buckypaper. They also exhibit a memory effect when bending wetted samples, returning to their former geometry on drying. Buckypaper and buckydiscs were studied by mercury intrusion porosimetry to reveal a defined distribution of mesopores and small macropores that is, along with their density and apparent free volume, dependant on the casting solvent and therefore tuneable. Moreover, the frit compression system also allows control over the 3-dimensional geometry of the buckydiscs during the casting process. 相似文献
100.
Catalan Janice; Toru Moriguchi; Slotnick Burton; Murthy Mahadev; Greiner Rebecca S.; Salem Norman Jr. 《Canadian Metallurgical Quarterly》2002,116(6):1022
This study investigated the influence of brain docosahexaenoic acid (DHA) deficiency on simple and complex olfactory-based learning and memory in 2nd generation (F2) adult male rats. Rats raised and maintained on either an n-3-adequate or an n-3-deficient diet were tested for acquisition of an olfactory learning set and an olfactory memory task, and for motivation to obtain a water reward. Despite a 76% decrease in brain DHA, n-3-deficient rats were able to acquire most simple 2-odor discrimination tasks but were deficient in the acquisition of a 20-problem olfactory learning set. This deficit could not be attributed to changes in sensory capacity but, instead, appeared to represent a deficit in higher order learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献