全文获取类型
收费全文 | 180篇 |
免费 | 3篇 |
专业分类
化学工业 | 111篇 |
金属工艺 | 3篇 |
机械仪表 | 8篇 |
矿业工程 | 1篇 |
能源动力 | 3篇 |
轻工业 | 1篇 |
无线电 | 7篇 |
一般工业技术 | 16篇 |
冶金工业 | 12篇 |
原子能技术 | 4篇 |
自动化技术 | 17篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 16篇 |
2012年 | 6篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 16篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1937年 | 1篇 |
1936年 | 2篇 |
排序方式: 共有183条查询结果,搜索用时 31 毫秒
1.
Students may choose to play drinking games not only for reasons related to alcohol consumption but also because of incentives related to other aspects of play (competition, fun, interpersonal dominance, etc.). College students (120 men and 167 women) completed measures of motives for playing (based on T. J. Johnson, S. Hamilton, & V. L. Sheets, 1999) and consequences of playing drinking games. Exploratory principal-components analysis identified 8 reasons for playing. Men and women differed in their endorsement of the factors. Motives for play directly predicted consequences of play independently of alcohol consumption. Specific motives predicted specific types of consequences. In multiple regression analyses, Conformity motives were negatively related to consequences and may represent a form of protective motive. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Two lignite samples, Beulah No. 3 and Big Brown No. 1, were liquefied at 420 °C using H2 and synthesis gas to determine the optimum beneficial amount of H2S in the batch autoclave reactor. Under the conditions employed, 50–100 psi partial pressure of H2S, nominally 4–10 wt% of daf lignite, was optimum for both samples. Synthesis gas outperformed H2 with and without H2S for the liquefaction of the two coals. 相似文献
3.
Summary The polymerization of 1-hexyne, 3,3-dimethyl-1-butyne, 2-hexyne and 1-chloro-1-hexyne by using metal halide based initiators was studied. By analogy with ionic ring opening polymerization systems, living acetylene polymerizations resulted when backbiting and interchain reactions were suppressed, i.e., ktr, kt=0. Large acetylenic substituents suppress the formation of cis-cisoidal propagating chains and subsequently eliminate backbiting reactions and also propagating carbene interchain reactions. Possible explanations for differences in polymer dispersities which result under different reaction conditions were also provided. 相似文献
4.
Braver Sanford L.; Wolchik Sharlene A.; Sandler Irwin N.; Sheets Virgil L.; Fogas Bruce; Bay R. Curtis 《Canadian Metallurgical Quarterly》1993,7(1):9
Reports the results of a 3-wave longitudinal study of a sizable, regionally representative sample of both noncustodial and custodial parents interviewed initially before their divorce was final. A model was tested that predicted the noncustodial parent's postdivorce contact with the child and the payment of child support from a series of factors related to a social exchange orientation. This orientation highlights the noncustodial parent's implicit calculation of the rewards vs the costs of continuing involvement and support of the child. It was found that noninvolvement was, in general, well-predicted, both cross-sectionally and longitudinally, by the model. The most powerful factor in the model was the noncustodial parent's perception that he or she had some control over the child's upbringing. Among fully employed noncustodial parents who reported high perceived control, there was an excellent record of involvement and child support payment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
This paper describes the synthesis and cation-radical polymerization of 1,5-bis(1-naphthoxy)-3-oxapentane. This monomer contains a flexible diethylene oxide unit between two 1-naphthalene rings. The FT-IR analysis of the resulted polymer indicates that it contains 1,4-disubstituted naphthalene structural units, i.e. 4,4-disubstituted-1,1-binaphthalene units. The polymer is crystalline with a melting point of 236 °C.Part IX: V. Percec and J. H. Wang: J. Mater. Chem., in press 相似文献
6.
Summary Free radical copolymerization of acrylonitrile (AN, M1) with poly(2,6-dimethyl-1,4-phenylene oxide)--vinylbenzyl ether (PPO-VBE, M2,
n + 4200g/mol,
w/
n + 1.04) was performed at 60°C in either a mixture of N,N-dimethylformamide/toluene or tetrahydrofuran, using 2,2-azoisobutyronitrile (AIBN) as initiator. The characterization of the resulting polyacrylonitrile grafted with poly(2,6-dimethyl-1,4-phenylene oxide) (PAN-g-PPO) was performed by 200 MHz 1H-NMR spectroscopy and solubility. 相似文献
7.
Summary This paper describes the synthesis and characterization of poly{3-[4-cyano-4-biphenyl)oxy]propyl vinyl ether} [poly(6-3)] macromonomers obtained by the functionalization of the growing chain end of the corresponding living polymer obtained by the initiation of the cationic polymerization of 3-[4-cyano-4-biphenyl)oxy]propyl vinyl ether with CF3SO3H/S(CH3)2, with 2-hydroxy ethyl methacrylate [poly(6-3)-I], 2-[2-(2-allyloxyethoxy)ethoxy]ethanol [poly(6-3)-II] and 10-undecen-1-ol [poly(6-3)-III].Part 20: V. Percec and M. Lee, J. Mater. Chem., submitted 相似文献
8.
This work continued our general research program on obtaining metallic cerium by electrodeposition from NaCeF4 dis-solved in different molten fluorides. The structure of NaCeF4 (cubic or hexagonal depe... 相似文献
9.
Jonathan Katz Philip MacKenzie Gelareh Taban Virgil Gligor 《Journal of Computer and System Sciences》2012,78(2):651-669
Typical protocols for password-based authentication assume a single server that stores all the information (e.g., the password) necessary to authenticate a user. An inherent limitation of this approach, assuming low-entropy passwords are used, is that the user?s password is exposed if this server is ever compromised. To address this issue, it has been suggested to share a user?s password information among multiple servers, and to have these servers cooperate (possibly in a threshold manner) when the user wants to authenticate. We show here a two-server version of the password-only key-exchange protocol of Katz, Ostrovsky, and Yung (the KOY protocol). Our work gives the first secure two-server protocol for the password-only setting (in which the user need remember only a password, and not the servers? public keys), and is the first two-server protocol (in any setting) with a proof of security in the standard model. Our work thus fills a gap left by the work of MacKenzie et al. (2006) [31] and Di Raimondo and Gennaro (2006) [16]. As an additional benefit of our work, we show modifications that improve the efficiency of the original KOY protocol. 相似文献
10.