全文获取类型
收费全文 | 3319篇 |
免费 | 242篇 |
专业分类
电工技术 | 39篇 |
综合类 | 1篇 |
化学工业 | 973篇 |
金属工艺 | 28篇 |
机械仪表 | 49篇 |
建筑科学 | 118篇 |
矿业工程 | 8篇 |
能源动力 | 66篇 |
轻工业 | 865篇 |
水利工程 | 22篇 |
石油天然气 | 21篇 |
无线电 | 184篇 |
一般工业技术 | 447篇 |
冶金工业 | 312篇 |
原子能技术 | 13篇 |
自动化技术 | 415篇 |
出版年
2024年 | 5篇 |
2023年 | 23篇 |
2022年 | 140篇 |
2021年 | 149篇 |
2020年 | 84篇 |
2019年 | 81篇 |
2018年 | 94篇 |
2017年 | 107篇 |
2016年 | 119篇 |
2015年 | 95篇 |
2014年 | 138篇 |
2013年 | 236篇 |
2012年 | 195篇 |
2011年 | 267篇 |
2010年 | 167篇 |
2009年 | 186篇 |
2008年 | 194篇 |
2007年 | 167篇 |
2006年 | 117篇 |
2005年 | 111篇 |
2004年 | 96篇 |
2003年 | 100篇 |
2002年 | 75篇 |
2001年 | 49篇 |
2000年 | 39篇 |
1999年 | 42篇 |
1998年 | 80篇 |
1997年 | 60篇 |
1996年 | 51篇 |
1995年 | 37篇 |
1994年 | 44篇 |
1993年 | 40篇 |
1992年 | 17篇 |
1991年 | 14篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1988年 | 18篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1974年 | 2篇 |
排序方式: 共有3561条查询结果,搜索用时 15 毫秒
11.
Naiara Azurmendi Iñaki Caro Amador C. Caballero Teresa Jardiel Marina Villegas 《Journal of the American Ceramic Society》2006,89(4):1232-1236
Bismuth titanate-based ceramics, pure and doped with 5 mol% WO3 , were prepared by reaction-sintering using a microwave oven. High densities, ≥96% of theoretical density were achieved with very short thermal treatments, with soaking time ranging from 5 to 15 min. Relatively small platelet-like grains were formed, and microstructure seemed not to be strongly affected by doping nor soaking time. Electrical measurements were performed and, as expected, a decrease of electrical conductivity was observed in WO3 -doped materials. The results of reaction-sintered samples, both conventional as well as microwave sintered, are compared with those of samples prepared with previously calcined powders and sintered using microwaves as well as a conventional electric furnace. 相似文献
12.
The stabilization problem for selected relative equilibria of an underactuated rigid body, modelling a simple underwater vehicle, moving in an ideal fluid is addressed. State feedback control laws achieving local asymptotic stability of a forward motion and of a diving/rising with forward/reverse motion are proposed. The control design exploits the Hamiltonian nature of the system to be controlled and it is based on the so-called interconnection and damping assignment (IDA) procedure. Simulation results complete the work. 相似文献
13.
14.
15.
Vicente Rodríguez Montequín Francisco Ortega Fernández Nicolás Abajo de Martínez Juan Antonio González Rodríguez 《JOM Journal of the Minerals, Metals and Materials Society》2002,54(7):46-50
This research summary discusses the application of neural networks, evolutionary strategies, and other artificial intelligence
techniques in the modeling and optimization of the models used for temperature, rolling force, and torque calculation in heavy
plate milling. 相似文献
16.
J Moreno Sierra ML Maestro de las Casas J Chicharro Almarza MD Ortega Heredia J López García-Asenjo C Merino Sánchez E Blanco Jiménez A Silmi Moyano L Rsesel Estévez 《Canadian Metallurgical Quarterly》1997,50(8):855-866
OBJECTIVE: The clinical course of transitional cell carcinoma of the bladder can be difficult to predict due to its potential to invade the muscle layer and/or develop to a high grade lesion. Bladder carcinoma can arise from genetic changes that may activate the oncogenes (-c-erbB2, c-erbB1, c-myc, ras, etc.) and/or inactivate the suppressor genes (p53, Rb). The aim of the present study is to continue a study protocol on the molecular biology of bladder tumors. METHODS/RESULTS: From January, 1993 to January, 1995, 85 patients were studied. These patients were divided into two groups: the first group comprised 14 controls of urothelial tissue and the second comprised 65 cases of transitional cell carcinoma of the bladder. p53 expression was determined by an immunohistochemical method (NCL-p53-DO7 monoclonal antibody). Quantification of the p8 oncoprotein in cytosol and EGFR (epidermal growth factor receptor) in membrane was performed by ELISA (Oncogene Science) and RIA (Vienna Lab), respectively. A statistically significant relationship between the expression of p53 and EGFR with tumor stage and grade was found. Quantification of p185 and EGFR showed higher values in the tumor tissue than in the control samples, but a worse survival could not be determined. CONCLUSIONS: The present study shows that p53 expression can be considered to be a prognostic factor. It provides useful information on the aggressive behaviour of the tumor and has a direct relation with the survival rates. 相似文献
17.
The therapeutic panorama of immunomodulation and its effects on the modification of the immune reaction is reviewed. Particular reference is made to the transfer factor as a therapeutic element in bronchial asthma, which insures its efficacy or innocuity. 相似文献
18.
Teresa Mikołajczyk Grażyna Janowska Mariusz Wójcik Maciej Boguń Andrzej Kurzak 《应用聚合物科学杂志》2008,109(4):2513-2521
The rheological properties of spinning solutions of polyacrylonitrile in dimethyl formamide (DMF) containing various amounts of a ferromagnetic nanoaddition were investigated. The porous structure, the strength and thermal properties of fibers obtained from these solutions were assessed, as well as the uniformity of the nanoaddition distribution on the fiber surface was estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
19.
Teresa Łuczak 《Journal of Applied Electrochemistry》2008,38(4):469-476
The electrooxidation of phenylethanolamine (2-amino-1-phenylethanol) at a gold electrode in alkaline electrolyte has been
studied. Measurement of the differential capacitance of the electric double layer versus the electrode potential has shown
that the adsorption of phenylethanolamine at the gold-solution interface plays a significant role in the oxidation mechanism.
The effect of amine concentration, electrolyte pH and potential scan rate on the electrooxidation is analysed. 相似文献
20.
Ernest Marco‐Urrea Xavier Gabarrell Gloria Caminal Teresa Vicent C Adinarayana Reddy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(9):1190-1196
BACKGROUND: Trichloroethylene (TCE) and perchloroethylene (PCE) are considered among the most important groundwater pollutants around the world. These compounds are usually found together in polluted environments but little is known about the ability of microorganisms to simultaneously degrade TCE and PCE. RESULTS: Data showed that several species of white‐rot fungi, including Trametes versicolor, Ganoderma lucidum, and Irpex lacteus, degrade substantial levels of TCE in pure culture. T. versicolor was chosen for further study since it degraded higher levels of TCE than the other organisms. Initial glucose concentration and reoxygenation of samples increased the amount of TCE dechlorination, but no significant difference in percentage TCE degradation was observed. T. versicolor was able to degrade 34.1 and 47.7% of PCE and TCE added as mixtures (containing 5 and 10 mg L−1, respectively). CONCLUSIONS: The degradation ability of TCE was extended to other species of white‐rot fungi. Percentage degradation as well as chloride release from mixtures of TCE and PCE showed that T. versicolor degrades mixtures of TCE and PCE almost as well as its ability to degrade individually added TCE or PCE. The results suggest the potential promise of T. versicolor for bioremediation of TCE and PCE in the environment. Copyright © 2008 Society of Chemical Industry 相似文献