全文获取类型
收费全文 | 743篇 |
免费 | 9篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 39篇 |
综合类 | 2篇 |
化学工业 | 244篇 |
金属工艺 | 22篇 |
机械仪表 | 31篇 |
建筑科学 | 10篇 |
能源动力 | 28篇 |
轻工业 | 60篇 |
水利工程 | 11篇 |
无线电 | 38篇 |
一般工业技术 | 151篇 |
冶金工业 | 19篇 |
原子能技术 | 14篇 |
自动化技术 | 87篇 |
出版年
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2018年 | 8篇 |
2017年 | 3篇 |
2016年 | 14篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 30篇 |
2012年 | 34篇 |
2011年 | 44篇 |
2010年 | 34篇 |
2009年 | 34篇 |
2008年 | 40篇 |
2007年 | 41篇 |
2006年 | 32篇 |
2005年 | 27篇 |
2004年 | 27篇 |
2003年 | 30篇 |
2002年 | 32篇 |
2001年 | 13篇 |
2000年 | 14篇 |
1999年 | 14篇 |
1998年 | 17篇 |
1997年 | 14篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 20篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 4篇 |
排序方式: 共有756条查询结果,搜索用时 8 毫秒
61.
Norio Tokuda Hitoshi Umezawa Sung-Gi Ri Masahiko Ogura Kikuo Yamabe Hideyo Okushi Satoshi Yamasaki 《Diamond and Related Materials》2008,17(7-10):1051-1054
A process of homoepitaxial growth of diamond (111) films by microwave plasma-enhanced chemical vapor deposition has been investigated characterizing areas by ex-situ atomic force microscopy. The evolution of surface morphology during a lateral growth of (111) diamond was visualized utilizing a mesa structure as a marker. Lateral growth forms atomically flat surfaces, which show atomically flat terraces over several hundred nm widths and single bilayer steps of (111) diamond. 相似文献
62.
Debasish Chakraborty Goutam Chakraborty Norio Shiratori 《International Journal of Network Management》2003,13(5):321-335
In this paper we propose a QoS‐based routing algorithm for dynamic multicasting. The complexity of the problem can be reduced to a simple shortest path problem by applying a Weighted Fair Queuing (WFQ) service discipline. Using a modified Bellman–Ford algorithm, the proposed routing builds a multicast tree, where a node is added to the existing multicast tree without re‐routing and satisfying QoS constraints. With user defined life‐time of connection this heuristic algorthm builds multicast tree which is near optimum over the whole duration of session. Simulation results show that tree costs are nearly as good as other dynamic multicast routings that does not consider QoS. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
63.
The so-called pseudo-orthogonal property of the eigenfunction expansion form is proved to be valid for the case of an antiplane interface V-notch and the corresponding path-independent integral is derived. The relation between the path-independent integral and the stress intensity factor of the notch is found. The influence of loads on the related integral is also presented. 相似文献
64.
Summary Introduction of isocyanate (NCO) group onto carbon black surface was achieved by the treatment of carbon black with toluene-2,4-diisocyanate. In addition, carbon black having acyl azide (CON3) group, a precursor of NCO group, was prepared by the reaction of COCl or COOCOOC2H5 group on carbon black with NaN3. The CON3 group on carbon black was relatively stable at below 20°C but readily decomposed to NCO group by heating (Curtius rearrangement). By the reation of NCO group on carbon black with hydroxyl group of polymers, such as polypropylene glycol, polyethylene glycol, and polyvinyl alcohol, these polymers were found to be grafted onto carbon black. 相似文献
65.
Hiroshi Taniguchi Toshiaki Ohmori Misao Iwata Norio Arai Kenji Hiraga Shun‐ichi Yamaguchi 《亚洲传热研究》2002,31(5):391-407
In this study, the authors attempted to introduce a simulation technique for radiation‐convection heat transfer in the high‐temperature fields of industrial furnaces, boilers, and gas turbine combustors. The convection effect was analyzed by a differential equation, but the radiation effect was analyzed by an integral equation. Thus, it was not easy to arrange both effects using the same type of equations. Then, the authors introduced the zone method and Monte Carlo method for the integral equation of the radiation effect and the finite difference method for the differential equation of the convection effect. A three‐dimensional analysis of the high‐temperature furnace was performed by this simulation technique to obtain its temperature distribution. Furthermore, another radiation‐convection heat transfer analysis in the low‐temperature living room was performed by the same technique. Finally, the authors tried to develop a computer software for radiation‐convection heat transfer and described their idea of software construction for the above. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(5): 391–407, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10042 相似文献
66.
Photoluminescence properties from water soluble CdSe/ZnS QDs encapsulated with hybrid trioctylphosphine-poly(acrylamide-co-acrylic acid)-ethanolamine (TOPO-PSMA-EA) shell have been investigated. It was found that PL efficiency of CdSe/ZnS QDs in water was increased 5–30% after introducing PSMA-EA polymers to encapsulate CdSe/ZnS-TOPO QDs. Higher PSMA concentrations were found to enhance the PL efficiency of QDs up to 1.8 folds, which is ascribed to a better packing and passivation of the TOPO-PSMA-EA shell over the QDs. Time-resolved photoluminescence suggested that the mean lifetime of photoexcited carriers in the water-soluble CdSe/ZnS-TOPO-PSMA-EA QDs elongated 2–17 ns compared with that of uncoated samples, indicating that PL quenching defects were effectively removed for CdSe/ZnS QDs with hybrid TOPO-PSMA-EA shell. 相似文献
67.
Artemisia princeps is commonly used as a food ingredient and in traditional Asian medicine. In this study, we examined the effects of long-term administration of an ethanol extract of A. princeps (APE) on body weight, white adipose tissue, blood glucose, insulin, plasma and hepatic lipids, and adipocytokines in C57BL/6 mice fed a high-fat diet. Daily feeding of a 1% APE diet for 14 weeks normalized elevated body weight, white adipose tissue, and plasma glucose and insulin levels, and delayed impaired glucose tolerance in mice a fed high-fat diet. These events were not observed in mice fed a control diet containing 1% APE. Liver triglyceride and cholesterol levels were similar in mice fed a 1% APE-diet and those fed a control diet. In the high-fat diet groups, APE inhibited hepatic fatty acid synthase (FAS) and suppressed the elevation of plasma leptin, but had no effect on adiponectin levels. These findings suggest that the regulation of leptin secretion by APE may inhibit FAS activity with subsequent suppression of triglyceride accumulation in the liver and adipose tissues. Inhibition of lipid accumulation can, in turn, lead to improvements in impaired glucose tolerance. 相似文献
68.
69.
70.
Summary The effect of initiating groups introduced onto silica surface on the molecular weight of grafted polystyrene chain was investigated. By the treatment of polystyrene-grafted silica with aqueous solution of alkali, surface grafted polystyrene was isolated from the surface. The molecular weight of polystyrene grafted onto the silica obtained from the radical graft polymerization initiated by peroxyester groups introduced onto the surface was found to be much larger than that from the cationic polymerization initiated by acylium perchlorate groups. The number of grafted polystyrene in the radical polymerization, however, was much less than that in the cationic polymerization. Furthermore, the effect of molecular weight of grafted polystyrene on the dispersibility of silica in tetrahydrofuran was examined. 相似文献