全文获取类型
收费全文 | 656篇 |
免费 | 47篇 |
专业分类
电工技术 | 11篇 |
综合类 | 2篇 |
化学工业 | 208篇 |
金属工艺 | 34篇 |
机械仪表 | 16篇 |
建筑科学 | 17篇 |
矿业工程 | 2篇 |
能源动力 | 14篇 |
轻工业 | 101篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 43篇 |
一般工业技术 | 143篇 |
冶金工业 | 37篇 |
原子能技术 | 5篇 |
自动化技术 | 67篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 13篇 |
2021年 | 38篇 |
2020年 | 15篇 |
2019年 | 13篇 |
2018年 | 27篇 |
2017年 | 37篇 |
2016年 | 35篇 |
2015年 | 26篇 |
2014年 | 34篇 |
2013年 | 58篇 |
2012年 | 41篇 |
2011年 | 56篇 |
2010年 | 28篇 |
2009年 | 29篇 |
2008年 | 28篇 |
2007年 | 23篇 |
2006年 | 15篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 12篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 12篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 13篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 8篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有703条查询结果,搜索用时 8 毫秒
1.
2.
M Zawadzka B Barański J Wi?niewska-Knypl T Wrońska-Nofer 《Canadian Metallurgical Quarterly》1993,6(4):391-397
Genotoxic effect and hepatic microsomal monooxygenase activities were assessed in mice treated with Acid Green 16 (single i.p. injection at dose 75 mg/kg) superimposed on prolonged ethanol consumption (10% solution in drinking water for 2-4 months). Treatment of mice with Acid Green 16 led to an increased frequency of micronucleated erythrocytes in bone marrow. In animals pretreated with ethanol the frequency of micronucleated erythrocytes, produced by Acid Green 16, was significantly higher. The changes in frequency of micronucleated erythrocytes were accompanied by the enhanced activity of microsomal monooxygenases manifested by higher activity of 7-ethoxycoumarin o-deethylase (the level of cytochrome P-450 was not altered). The obtained results showed that ethanol tended to increase the genotoxic effect of Acid Green 16. However, the slight inductive effect of ethanol on microsomal monooxygenases did not provide clear evidence that the genotoxic effect of Acid Green 16 was associated with ethanol stimulation of the metabolic activation of the dye in the liver. 相似文献
3.
Thick film technology was used to manufacture a solid-state electrochemical nitrogen dioxide sensor. The prepared sensor
has a linear dependence of electromotive force that is based in the NO2 concentration level. This paper presents discussion on a thick-film sensor that has a much smaller dimension and shorter
response time as compared to typical ceramic solid-state electrochemical devices.
Received: 26 February 1996/Accepted: 27 June 1996 相似文献
4.
The interactions of NO with carbon and carbon-supported catalysts have been investigated by means Fourier transform infrared spectroscopy. Nitric oxide direct decomposition over carbon-supported catalysts (Cu, Pt) was studied in a temperature ranging from 473 to 623 K. NO conversion increased with increasing reaction temperature in the whole temperature range. The carbon-supported Pt catalyst has a very high activity for the decomposition of NO in the absence of oxygen. As a result of NO chemisorption isocyanate (-NCO) species on the surface of carbon containing Cu were observed. When the reaction temperature was increased, the -NCO band at 2229 cm−1 became more intense. 相似文献
5.
6.
Bartosz Więckowski 《Journal of Logic, Language and Information》2016,25(2):215-268
A first-order language with a defined identity predicate is proposed whose apparatus for atomic predication is sensitive to grammatical categories of natural language (e.g., common nouns, verbs, adjectives, adverbs, modifiers). Subatomic natural deduction systems are defined for this naturalistic first-order language. These systems contain subatomic systems which govern the inferential relations which obtain between naturalistic atomic sentences and between their possibly composite components. As a main result it is shown that normal derivations in the defined systems enjoy the subexpression property which subsumes the subformula property with respect to atomic and identity formulae as a special case. The systems admit a proof-theoretic semantics which does not only apply to logically compound but also to atomic and identity formulae—as well as to their components. The potential of the defined systems for a meticulous first-order analysis of natural inferences whose validity crucially depends on expressions of some of the aforementioned categories is demonstrated. 相似文献
7.
Abstract The success of the testing of volatile organic compounds emitted by animals is dependent on the creation of appropriate conditions for air sampling subsequently used to assay and identify the compounds. These conditions play a particularly important role in the investigation of pheromones, which are secreted in extremely low concentrations. The authors have not come across any previous work which offers constructional solutions, which would allow avoidance of contamination of the air samples containing volatile substances secreted by animals. A constructional solution was developed, which provides optimal conditions for their sampling and isolation. Its main advantages are as follows: the exposure chamber (the chamber in which the animal is studied) is filled with synthetic air; the exposure chamber is separated from the atmospheric air with a synthetic air “jacket”; the exposure chamber has been constructed using materials which do not release chemicals and absorb them in trace quantities. 相似文献
8.
Tomasz Gancarz Przemysław Fima Janusz Pstruś 《Journal of Materials Engineering and Performance》2014,23(5):1524-1529
Thermal expansion and electrical resistivity of alloys based on Sn-Zn eutectic with 0.5, 1.0, 1.5, and 4.0 wt.% additions of In were studied. Thermal expansion measurements were performed using thermomechanical analysis tester over 223-373 K temperature range. Electrical resistivity measurements were performed with four-probe method over 298-423 K temperature range. The electrical resistivity of alloys increases linearly with temperature and concentration of In; also coefficient of thermal expansion of the studied alloys increases with In concentration. Scanning electron microscopy revealed simple eutectic microstructure with In dissolved in Sn-rich matrix. The results obtained were compared with the available literature data. Spreading tests on Cu of Sn-8.8Zn alloys with 0.5, 1.0, and 1.5 at.% of In were performed. Wetting tests were performed at 250 °C, by sessile drop method, by means of flux, and wetting times were 3, 8, 15, 30, and 60 min. In general, no clear effect of wetting time on spreading was observed. 相似文献
9.
10.
Effect of the structure of polymer inclusion membranes on zn(II) transport from chloride aqueous solutions 下载免费PDF全文
This article presents application of polymer inclusion membranes (PIM) containing polymer matrices: cellulose triacetate (CTA) or poly(vinyl) chloride (PVC), o‐nitrophenyloctyl ether (NPOE) as a plasticizer and phosphonium ionic liquids, i.e., trihexyltetradecylphosphonium chloride (Cyphos IL 101), bis(2,4,4‐trimethylpentyl)phosphinate (Cyphos IL 104) and tributyltetradecylphosphonium chloride (Cyphos IL 167), as carriers for Zn(II) transport from chloride medium. Cyphos IL167 application as an ion carrier in PIMs is reported for the first time. The membrane composition is found to affect Zn(II) transport significantly. SEM and AFM images show the differences in the surface morphology of PVC and CTA based membranes. Better transport abilities of CTA membranes (Zn(II) recovery factors exceed 80%) compared with those of PVC, indicate that the structural differences between the two polymers play a crucial role for the membrane permeability. The best initial flux and permeability coefficient are obtained for the membranes with Cyphos IL 101 and Cyphos IL 104 as carriers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42319. 相似文献