全文获取类型
收费全文 | 222篇 |
免费 | 27篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 58篇 |
金属工艺 | 4篇 |
机械仪表 | 5篇 |
建筑科学 | 1篇 |
能源动力 | 1篇 |
轻工业 | 55篇 |
水利工程 | 3篇 |
无线电 | 19篇 |
一般工业技术 | 25篇 |
冶金工业 | 52篇 |
自动化技术 | 19篇 |
出版年
2023年 | 3篇 |
2021年 | 18篇 |
2020年 | 15篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1964年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有249条查询结果,搜索用时 671 毫秒
11.
12.
Two important forces in human behavior are action and inaction. Although action and inaction are commonly associated with the presence and the absence of behavioral activity, they can also be represented as information processing goals. Action (inaction) goals influence decision effort and increase satisfaction with environments that are structured to allow for more (less) processing (Studies 1 and 2). This increased satisfaction can transfer to the decision (Study 3) and can increase the intent to perform a decision-congruent behavior (Studies 4 and 6). Finally, the author shows escalation of action and inaction goals when they are not achieved (Study 5) and rebound of the alternative goal when the focal goal is achieved (Study 6). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
Juliano B. Lima Ricardo M. Campello de Souza 《Applicable Algebra in Engineering, Communication and Computing》2011,22(5-6):393-411
In this paper, the finite field trigonometric transforms (FFTT) are introduced. The FFTT family includes eight types of cosine transforms and eight types of sine transforms, which are developed from concepts related to the finite field trigonometry. New lemmas are presented and some properties of the FFTT are discussed. 相似文献
14.
In this paper, three issues related to three‐dimensional multilink rigid body systems are considered: dynamics, actuation, and inversion. Based on the Newton‐Euler equations, a state space formulation of the dynamics is discussed that renders itself to inclusion of actuators, and allows systematic ways of stabilization and construction of inverse systems. The development here is relevant to robotic systems, biological modeling, humanoid studies, and collaborating man‐machine systems. The recursive dynamic formulation involves a method for sequential measurement and estimation of joint forces and couples for an open chain system. The sequence can start from top downwards or from the ground upwards. Three‐dimensional actuators that produce couples at the joints are included in the dynamics. Inverse methods that allow estimation of these couples from the kinematic trajectories and physical parameters of the system are developed. The formulation and derivations are carried out for a two‐link system. Digital computer simulations of a two‐rigid body system are presented to demonstrate the feasibility and effectiveness of the methods. © 2005 Wiley Periodicals, Inc. 相似文献
15.
St Hilaire PM Alves LC Sanderson SJ Mottram JC Juliano MA Juliano L Coombs GH Meldal M 《Chembiochem : a European journal of chemical biology》2000,1(2):115-122
The substrate specificity of CPB2.8DeltaCTE, a recombinant cysteine protease from Leishmania mexicana, was mapped by screening a fluorescence-quenched combinatorial peptide library. Results from library screening indicated a preference for Arg or Lys in the S(3) subsite and for hydrophobic residues, both aliphatic and aromatic, in S(2). The S(1) subsite exhibited a specificity for the basic residues Arg and Lys. Generally, the specificity of the primed subsites was less strict compared with the non-primed side which showed preference for Arg, Lys and Ala in S'(1), Arg, Pro and Gly in S'(2) and Lys, Arg and Ser in S'(4). By contrast, a strict preference for the basic residues Arg and Lys was found for S'(3). Overall, there was a trend for basic residues in alternating subsites and smaller residues in the primed sites compared with the non-primed sites. In addition, there were strict requirements for the amino acids in subsites S(3)--S(1). Fluorescence-quenched peptides from the library with the highest on-resin cleavage were resynthesised and their kinetics of hydrolysis by CPB2.8DeltaCTE assessed in solution phase assays. Several good substrates containing the quintessential dipeptide particular to cathepsin-L-like enzymes, -F-R/K-, in P(2) and P(1) were identified (e.g. Y(NO(2))-EKFR down arrow RGK-K(Abz)G, Abz=2-aminobenzoyl; k(cat)K(m)(-1)=4298 mM(-1)s(-1)). However, novel substrates containing the dipeptide -L/I-Q- in P(2) and P(1) were also well hydrolysed (e.g. Y(NO(2))-YLQ down arrow GIQK-K(Abz)G; k(cat)K(m)(-1)=2583 mM(-1)s(-1)). The effect of utilising different fluorescent donor--quencher pairs on the value of k(cat)K(m)(-1) was examined. Generally, the use of the Abz/Q-EDDnp donor--quencher pair (EDDnp=N-(2,4-dinitrophenyl)ethylenediamine) instead of K(Abz)/Y(NO(2)) resulted in higher k(cat)K(m)(-1) values for analogous substrates. 相似文献
16.
Palestri P. Barin N. Brunel D. Busseret C. Campera A. Childs P. A. Driussi F. Fiegna C. Fiori G. Gusmeroli R. Iannaccone G. Karner M. Kosina H. Lacaita A. L. Langer E. Majkusiak B. Compagnoni C. M. Poncet A. Sangiorgi E. Selmi L. Spinelli A. S. Walczak J. 《Electron Devices, IEEE Transactions on》2007,54(1):106-114
In this paper, we compare the capacitance-voltage and current-voltage characteristics of gate stacks calculated with different simulation models developed by seven different research groups, including open and closed boundaries approaches to solve the Schroumldinger equation inside the stack. The comparison has been carried out on template device structures, including pure SiO2 dielectrics and high-kappa stacks, forcing the use of the same physical parameters in all models. Although the models are based on different modeling assumptions, the discrepancies among results in terms of capacitance and leakage current are small. These discrepancies have been carefully investigated by analyzing the individual modeling parameters and the internal quantities (e.g., tunneling probabilities and subband energies) contributing to current and capacitance 相似文献
17.
18.
P Lanotte F Dubois S Le Pogam C Guerois B Fimbel Y Bacq Y Gruel A Goudeau F Barin 《Canadian Metallurgical Quarterly》1998,178(2):556-559
Several studies have reported the spontaneous loss of hepatitis C virus (HCV) antibodies in HCV-exposed persons. However, the relationship between seroreversion and spontaneous virus clearance has yet to be precisely determined in a single homogeneous population of untreated immunocompetent patients. In this study, 32 human immunodeficiency virus-seronegative hemophiliacs who had been exposed to HCV were followed for a mean duration of 141 months; 22 remained chronic carriers (68.8%). All but 1 of the nonviremic patients (90.0%) showed partial (8 cases) or complete (2 cases) seroreversion. In contrast, all but 1 of the viremic patients (95.1%) had a stable serologic profile when analyzed by a recombinant immunoblot assay. The results indicate that any HCV antibody-positive immunocompetent patient with no detectable serum HCV RNA and normal alanine aminotransferase values and whose serial samples show a progressive decrease in the level of HCV antibodies present may be considered as having a resolved infection. 相似文献
19.
Juliano Toniolo Antonio S. Takimi Mônica J. Andrade Renato Bonadiman Carlos P. Bergmann 《Journal of Materials Science》2007,42(13):4785-4791
This article describes the solution combustion synthesis technique as applicable to iron oxide powder production using urea
as fuel and ferric nitrate as an oxidizer. It focuses on the thermodynamic modeling of the combustion reaction under different
fuel-to-oxidant ratios. X-ray diffraction showed magnetite (Fe3O4) and hematite (α-Fe2O3) phase formations for the as-synthesized powders. The smallest crystallite size was obtained by stoichiometric chemical reaction.
The magnetic properties of the samples are also carefully discussed as superparamagnetic behavior. 相似文献
20.
Juliano C Cossu M Rota MT Satta D Poggi P Giunchedi P 《Drug development and industrial pharmacy》2011,37(10):1192-1199
There is growing evidence that a large proportion of upper digestive tract tumors are ascribable to heavy alcohol drinking and tobacco consumption. The cancer-promoting action of ethanol is mediated by acetaldehyde, its first metabolite, also derived from the bacterial oxidation of alcohol by the oral microflora, classified by the International Agency for the Research on Cancer as a carcinogen. Acetaldehyde is also one of the major components of tobacco smoke. These findings suggest two different strategies to decrease the risk of alcohol-related oral cancers: the reduction of the levels of alcohol-derived acetaldehyde in saliva and the reduction of oral bacterial flora. Therefore, the aim of our study was to develop and characterize some buccal tablet formulations containing both 20 mg L-cysteine hydrochloride (able to chemically neutralize acetaldehyde) and 10 mg chlorhexidine diacetate (well-known antiseptic compound active against a large spectrum of oral microbes). One of these formulations, chosen on the basis of its favourable delivery kinetics of the active principles, was demonstrated to be able to reduce acetaldehyde concentration in an in vitro system and to lower its salivary levels in volunteers after ethanol contact. Our findings support the hypothesis that the application of buccal devices containing cysteine and chlorhexidine could reduce salivary acetaldehyde levels and thus the incidence of upper gastrointestinal cancer in drinkers and smokers. 相似文献