全文获取类型
收费全文 | 445篇 |
免费 | 19篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 120篇 |
金属工艺 | 1篇 |
机械仪表 | 13篇 |
建筑科学 | 10篇 |
能源动力 | 17篇 |
轻工业 | 44篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 43篇 |
一般工业技术 | 53篇 |
冶金工业 | 90篇 |
原子能技术 | 11篇 |
自动化技术 | 58篇 |
出版年
2023年 | 2篇 |
2022年 | 29篇 |
2021年 | 18篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 26篇 |
2012年 | 28篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 21篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 15篇 |
2004年 | 7篇 |
2003年 | 16篇 |
2002年 | 8篇 |
2001年 | 11篇 |
1999年 | 3篇 |
1998年 | 31篇 |
1997年 | 21篇 |
1996年 | 17篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1965年 | 1篇 |
1914年 | 1篇 |
1912年 | 1篇 |
排序方式: 共有466条查询结果,搜索用时 15 毫秒
1.
M Valenti G Cimoli S Parodi GL Mariani M Venturini P Conte P Russo 《Canadian Metallurgical Quarterly》1993,(8):1157-1161
Synergism between recombinant human tumour necrosis factor (rHuTNF) and DNA topoisomerase II inhibitor VP16 during the killing of cells has been studied in six human ovarian cancer cell lines (A2774, A2780, SW626, IGROV-1, SKOV3, Pa1) and a cervical carcinoma cell line (Me180). Studies were performed using an assay of colony formation inhibition (drug treatment for 1 h) and a growth inhibition assay (continuous exposure for 20 h). Concomitant treatment of cells with VP16+rHuTNF enhanced cell killing in all the cell lines tested--an effect observed in both short- and long-term cytotoxicity assays. This study suggests that the activity of VP16 in ovarian cancer cell lines might be enhanced by rHuTNF in in vitro models. 相似文献
2.
The a.c. conductivity of the proteins lysozyme and subtilisin, both in their active and inactive or inhibited forms were determined theoretically. For this, quantum mechanical calculations and a random walk theory were used. The conclusions are that these enzymatic proteins can easily transport electrons which is most probably important in their role as catalysators of biochemical reactions. The electron transport is sensitive to three-dimensional changes of the active sites of these enzymes which have more flexibility than the whole molecule. Therefore, the flexibility of the active sites of enzyme catalysts is not only important for the conformational fitting with the reactants, but also strongly influences the transport in biochemical reactions. 相似文献
3.
E Di Cesare M Sabatini A Splendiani C Masciocchi 《Canadian Metallurgical Quarterly》1998,96(1-2):113-115
A wandering spleen and splenic cysts are uncommon conditions in children. A combination of both entities has only rarely been reported in the literature. Another case of this complex pathology in 12-year-old girl is presented. She was initially referred for evaluation of a large abdominal mass. Diagnostic studies raised the suspicion of a hematoma in an abnormally located spleen, but the definitive diagnosis was established at laparotomy. Successful surgical management consisted of total cystectomy and splenopexy. 相似文献
4.
Nanoindentation Characterization of Submicro- and Nano-Sized Liquid-Phase-Sintered SiC Ceramics 总被引:1,自引:0,他引:1
Stefano Guicciardi Diletta Sciti Cesare Melandri Alida Bellosi 《Journal of the American Ceramic Society》2004,87(11):2101-2107
Submicro- and nano-sized liquid-phase-sintered SiC ceramics were mechanically tested by nanoindentation in the peak load range 5–400 mN. The submicro-sized sample showed a marked indentation size effect which the nano-sized samples did not exhibit. The relevance of indentation depth with respect to the microstructural scale has been outlined. In the investigated grain-size range, the hardness dependence on the grain size could be described by a load-dependent inverse Hall–Petch relation. Young's modulus was less microstructure- and load-dependent. Because of the very fine microstructure, the nano-sized SiC materials gave lower elastic values than the submicro-sized SiC ceramic. 相似文献
5.
A method for the calibration of a 3-D laser scanner 总被引:1,自引:0,他引:1
The calibration of a three-dimensional digitizer is a very important issue to take into consideration that good quality, reliability, accuracy and high repeatability are the features which a good digitizer is expected to have. The aim of this paper is to propose a new method for the calibration of a 3-D laser scanner, mainly for robotic applications. The acquisition system consists of a laser emitter and a webcam with fixed relative positions. In addition, a cylindrical lens is provided with the laser housing so that it is capable to project a plane light. An optical filter was also used in order to segment the laser stripe from the rest of the scene. For the calibration procedure it was used a digital micrometer that move a target with known dimensions. The calibration method is based on the modeling of the geometrical relationship between the 3-D coordinates of the laser stripe on the target and its digital coordinates in the image plane. By this method it is possible to calibrate the intrinsic parameters of the video system, the position of the image plane and the laser plane in a given frame, all in the same time. 相似文献
6.
RESTful Web service composition with BPEL for REST 总被引:4,自引:0,他引:4
7.
8.
9.
Roberta Caponi Andrea Monforti Ferrario Enrico Bocci Gianluca Valenti Massimiliano Della Pietra 《International Journal of Hydrogen Energy》2021,46(35):18630-18643
The foreseen uptake of hydrogen mobility is a fundamental step towards the decarbonization of the transport sector. Under such premises, both refueling infrastructure and vehicles should be deployed together with improved refueling protocols. Several studies focus on refueling the light-duty vehicles with 10 kgH2 up to 700 bar, however less known effort is reported for refueling heavy-duty vehicles with 30–40 kgH2 at 350 bar. The present study illustrates the application of a lumped model to a fuel cell bus tank-to-tank refueling event, tailored upon the real data acquired in the 3Emotion Project. The evolution of the main refueling quantities, such as pressure, temperature, and mass flow, are predicted dynamically throughout the refueling process, as a function of the operating parameters, within the safety limits imposed by SAE J2601/2 technical standard. The results show to refuel the vehicle tank from half to full capacity with an Average Pressure Ramp Rate (APRR) equal to 0.03 MPa/s are needed about 10 min. Furthermore, it is found that the effect of varying the initial vehicle tank pressure is more significant than changing the ambient temperature on the refueling performances. In conclusion, the analysis of the effect of different APRR, from 0.03 to 0.1 MPa/s, indicate that is possible to safely reduce the duration of half-to-full refueling by 62% increasing the APRR value from 0.03 to 0.08 MPa/s. 相似文献
10.
George D. Quinn Cesare Melandri Goffredo de Portu 《Journal of the American Ceramic Society》2013,96(7):2283-2291
The edge chipping test was used to measure the fracture resistance of alumina/alumina‐zirconia laminated structures. Tailored, symmetrical laminated structures were prepared with a variety of layer thickness. The laminates had a significantly greater edge chipping resistance. Laminates with thin layers were just as effective in impeding edge chips as laminates with thick layers. 相似文献