全文获取类型
收费全文 | 2282篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 17篇 |
化学工业 | 240篇 |
金属工艺 | 49篇 |
机械仪表 | 36篇 |
建筑科学 | 121篇 |
矿业工程 | 7篇 |
能源动力 | 66篇 |
轻工业 | 202篇 |
水利工程 | 14篇 |
石油天然气 | 10篇 |
无线电 | 172篇 |
一般工业技术 | 372篇 |
冶金工业 | 771篇 |
原子能技术 | 13篇 |
自动化技术 | 226篇 |
出版年
2022年 | 14篇 |
2021年 | 13篇 |
2019年 | 18篇 |
2018年 | 13篇 |
2017年 | 21篇 |
2015年 | 20篇 |
2014年 | 24篇 |
2013年 | 115篇 |
2012年 | 55篇 |
2011年 | 85篇 |
2010年 | 70篇 |
2009年 | 59篇 |
2008年 | 71篇 |
2007年 | 77篇 |
2006年 | 67篇 |
2005年 | 71篇 |
2004年 | 62篇 |
2003年 | 56篇 |
2002年 | 42篇 |
2001年 | 49篇 |
2000年 | 46篇 |
1999年 | 52篇 |
1998年 | 216篇 |
1997年 | 119篇 |
1996年 | 82篇 |
1995年 | 72篇 |
1994年 | 75篇 |
1993年 | 64篇 |
1992年 | 36篇 |
1991年 | 22篇 |
1990年 | 20篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 21篇 |
1986年 | 22篇 |
1985年 | 23篇 |
1984年 | 21篇 |
1983年 | 14篇 |
1982年 | 26篇 |
1981年 | 24篇 |
1980年 | 18篇 |
1979年 | 24篇 |
1978年 | 24篇 |
1977年 | 37篇 |
1976年 | 60篇 |
1975年 | 16篇 |
1974年 | 13篇 |
1973年 | 19篇 |
1972年 | 14篇 |
1968年 | 13篇 |
排序方式: 共有2316条查询结果,搜索用时 16 毫秒
101.
Edwards Bryan D.; Day Eric Anthony; Arthur Winfred Jr.; Bell Suzanne T. 《Canadian Metallurgical Quarterly》2006,91(3):727
This study examined the relationship between the similarity and accuracy of team mental models and compared the extent to which each predicted team performance. The relationship between team ability composition and team mental models was also investigated. Eighty-three dyadic teams worked on a complex skill task in a 2-week training protocol. Results indicated that although similarity and accuracy of team mental models were significantly related, accuracy was a stronger predictor of team performance. In addition, team ability was more strongly related to the accuracy than to the similarity of team mental models and accuracy partially mediated the relationship between team ability and team performance, but similarity did not. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
102.
Holden Ronald R.; Wasylkiw Louise; Starzyk Katherine B.; Book Angela S.; Edwards Melanie J. 《Canadian Metallurgical Quarterly》2006,38(1):24
Four studies investigated the dimensionality of the NEO Five-Factor Inventory (NEO-FFI; P. T. Costa & R. R. McCrae, 1992). In Study 1, four inferential dimensions and four clusters represented the NEO-FFI when 114 undergraduates freely sorted items into categories. Construct validity for four item-clusters derived from the inferential space was obtained in Study 2 based on self-report with 304 undergraduates. Study 3 validated these inferential clusters using self and peer reports for 420 undergraduates. Study 4 validated the cluster scales for predicting quality of life and significant social and cultural behaviours for 110 undergraduates. Implications for implicit personality theory, the number of dimensions issue in personality, and test construction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
Mrten O. M. Edwards Roger Persson 《Journal of the Society for Information Display》2005,13(12):1035-1037
Abstract— The electro‐optical characteristics of a pixel configuration used in electrochromic viologen‐TiO2 passive‐matrix devices are studied. The configuration has two stable color states in an intermediate voltage regime. Color switching is performed by applying voltages outside this regime. The bistability is due to electrolyte‐additive controlled electron trapping in the color‐changing viologen molecules. 相似文献
104.
Wenjiang Shen Edwards R.T. Chang-Jin Kim 《Journal of microelectromechanical systems》2006,15(4):879-889
The dominance of surface tension over inertia in microscale and favorable scale effect for electrostatic actuation allow electrostatically driven metal-droplet systems practical. Because of such potential advantages as low contact resistance, naturally bistable operation, and high switch density, the liquid-metal droplet switch is an excellent candidate for reconfigurable circuit interconnections. Following earlier droplet microswitch examples and related studies of metal-droplet behavior, we report the first functioning droplet switch directly integrated on top of a functional CMOS circuit. While the surface tension dominance makes the droplet switches practical as a mechanical system and also brings bistability, it also requires a high electric field to move the droplet. We implement the concept of physical surface modification to lower the driving voltage to a value that a commercial CMOS process can provide. Unlike previous droplet switches, the reported device is planar-processed to allow the integration with the underlying CMOS circuits. The integrated switch is made functional by such provisions as self-limiting actuation and by optimizing the electrostatic force in the planar configuration and avoiding liquid-metal "flooding" into surface patterns. A fabrication process for low driving voltage and high compatibility is developed to integrate the droplet switch on the custom-developed CMOS chip. A packaging method adapted from well-established microelectronic packaging isolates the active switch space from the surrounding environment. Low driving voltage (as low as 15 V) and millisecond switching speed are achieved by the current on-chip device. While the current device uses /spl sim/150 /spl mu/m droplets for demonstration, additional theoretical and experimental results indicate that further miniaturization would lead to smaller devices and lower operation voltage. 相似文献
105.
Minimizing risk using prediction uncertainty in neural networkestimation fusion and its application to papermaking 总被引:1,自引:0,他引:1
Edwards P.J. Peacock A.M. Renshaw D. Hannah J.M. Murray A.F. 《Neural Networks, IEEE Transactions on》2002,13(3):726-731
The paper presents Bayesian information fusion theory in the context of neural-network model combination. It shows how confidence measures can be combined with individual model estimates to minimize risk through the fusion process. The theory is illustrated through application to the real task of quality prediction in the papermaking industry. Prediction uncertainty estimates are calculated using approximate Bayesian learning. These are incorporated into model combination as confidence measures. Cost functions in the fusion center are used to control the influence of the confidence measures and improve the performance of the resultant committee. 相似文献
106.
Pfizer Inc. is a research based global pharmaceutical company committed to the discovery and development of innovative medicines that improve the quality of life of individuals throughout the world. In order to gain a competitive advantage over competitor companies in the discovery of new medicines, we must speed up drug discovery and drive down costs. Using non-combinatorial chemistry techniques increases the efficiency with which we discover new ‘leads,’ leveraging our drug discovery efforts through retaining complete control over the properties of each product made. Compound purification, managed through in-house software, augments the quality of data obtained upon biological screening of compounds. 相似文献
107.
108.
G Chow IG Roberts P Fallon M Onoe A Lloyd-Thomas MJ Elliott AD Edwards FJ Kirkham 《Canadian Metallurgical Quarterly》1997,11(4):633-639
BACKGROUND: The precise mechanisms involved in islet xenograft rejection remain unknown. The purpose of the present study was to determine cellular mechanisms responsible for islet xenograft rejection in the liver to facilitate finding a procedure for prevention of immune rejection. METHODS: Hepatic mononuclear cells (MNC) as well as splenocytes, peripheral blood MNC, and thymocytes from streptozotocin-induced diabetic mice (BALB/c) rejecting the intrahepatic rat (Lewis) islet xenografts were isolated and examined by two-color FACS analysis. RESULTS: The characteristic finding of the hepatic MNC from the mice rejecting islet xenografts compared with mice receiving isografts was a significant increase in the yield as well as in the percentage of the cells expressing CD3+ interleukin-2 receptor (IL-2R) alpha- beta+, CD3+ CD8alpha+ beta+, and T cell receptor (TCR) alphabeta+ lymphocyte function-associated antigen-1+. The expression of CD3 and TCR alphabeta of these T cells was found to be of intermediate intensity (TCR(int) cells). The expansion of these TCR(int) cells occurred predominantly in the liver. There was no significant difference in the cells expressing CD3+ IL-2R alpha+, CD3+ CD4+, CD3+ TCRgammadelta+, CD3- IL-2Rbeta+ (natural killer cells), and B220+ (B cells). In vivo administration of anti-IL-2Rbeta monoclonal antibody directed to the expanded cells produced a prevention of rejection. CONCLUSIONS: These findings suggest that islet xenograft rejection in the liver from rat to mouse is an event for which the TCR(int) cells are responsible. 相似文献
109.
Edwards G.S. Evertson D. Gabella W. Grant R. King T.L. Kozub J. Mendenhall M. Jin Shen Shores R. Storms S. Traeger R.H. 《IEEE journal of selected topics in quantum electronics》1996,2(4):810-817
The Vanderbilt free-electron laser (FEL) is a continuously tunable source of pulsed, mid-infrared radiation. FEL applications research has been underway for a decade. Recent experimental advances in FEL ablation of soft tissue indicate the potential for FEL-based protocols in surgery and medicine. In anticipation of these medical applications, the Vanderbilt FEL is being upgraded to meet the reliability and performance standards for a medical laser. Facilities for laser surgery have been constructed and equipped and medical delivery systems are being developed for pre-clinical and clinical research 相似文献
110.