全文获取类型
收费全文 | 1564篇 |
免费 | 40篇 |
专业分类
电工技术 | 5篇 |
综合类 | 1篇 |
化学工业 | 244篇 |
金属工艺 | 33篇 |
机械仪表 | 21篇 |
建筑科学 | 69篇 |
矿业工程 | 4篇 |
能源动力 | 26篇 |
轻工业 | 168篇 |
水利工程 | 7篇 |
石油天然气 | 8篇 |
无线电 | 75篇 |
一般工业技术 | 215篇 |
冶金工业 | 507篇 |
原子能技术 | 9篇 |
自动化技术 | 212篇 |
出版年
2022年 | 19篇 |
2021年 | 25篇 |
2020年 | 15篇 |
2019年 | 11篇 |
2018年 | 17篇 |
2017年 | 17篇 |
2016年 | 20篇 |
2015年 | 19篇 |
2014年 | 25篇 |
2013年 | 67篇 |
2012年 | 42篇 |
2011年 | 80篇 |
2010年 | 48篇 |
2009年 | 57篇 |
2008年 | 55篇 |
2007年 | 66篇 |
2006年 | 53篇 |
2005年 | 41篇 |
2004年 | 44篇 |
2003年 | 63篇 |
2002年 | 49篇 |
2001年 | 27篇 |
2000年 | 21篇 |
1999年 | 25篇 |
1998年 | 48篇 |
1997年 | 41篇 |
1996年 | 35篇 |
1995年 | 33篇 |
1994年 | 25篇 |
1993年 | 37篇 |
1992年 | 21篇 |
1991年 | 12篇 |
1990年 | 25篇 |
1989年 | 27篇 |
1988年 | 25篇 |
1987年 | 14篇 |
1986年 | 21篇 |
1985年 | 19篇 |
1984年 | 32篇 |
1983年 | 23篇 |
1982年 | 22篇 |
1981年 | 29篇 |
1980年 | 25篇 |
1979年 | 20篇 |
1978年 | 18篇 |
1977年 | 13篇 |
1976年 | 17篇 |
1973年 | 14篇 |
1971年 | 9篇 |
1970年 | 11篇 |
排序方式: 共有1604条查询结果,搜索用时 15 毫秒
1.
2.
Dr. Li Di Prof. Per Artursson Dr. Alex Avdeef Prof. Leslie Z. Benet Prof. J. Brian Houston Dr. Manfred Kansy Edward H. Kerns Prof. Hans Lennernäs Dr. Dennis A. Smith Prof. Kiyohiko Sugano 《ChemMedChem》2020,15(20):1862-1874
Passive permeability is a key property in drug disposition and delivery. It is critical for gastrointestinal absorption, brain penetration, renal reabsorption, defining clearance mechanisms and drug-drug interactions. Passive diffusion rate is translatable across tissues and animal species, while the extent of absorption is dependent on drug properties, as well as in vivo physiology/pathophysiology. Design principles have been developed to guide medicinal chemistry to enhance absorption, which combine the balance of aqueous solubility, permeability and the sometimes unfavorable compound characteristic demanded by the target. Permeability assays have been implemented that enable rapid development of structure-permeability relationships for absorption improvement. Future advances in assay development to reduce nonspecific binding and improve mass balance will enable more accurately measurement of passive permeability. Design principles that integrate potency, selectivity, passive permeability and other ADMET properties facilitate rapid advancement of successful drug candidates to patients. 相似文献
3.
Leslie Lamport 《Acta Informatica》1980,14(1):21-37
Summary Hoare's logical system for specifying and proving partial correctness properties of sequential programs is generalized to concurrent programs. The basic idea is to define the assertion {P} S {Q} to mean that if execution is begun anywhere in S with P true, then P will remain true until S terminates, and Q will be true if and when S terminates. The predicates P and Q may depend upon program control locations as well as upon the values of variables. A system of inference rules and axiom schemas is given, and a formal correctness proof for a simple program is outlined. We show that by specifying certain requirements for the unimplemented parts, correctness properties can be proved without completely implementing the program. The relation to Pnueli's temporal logic formalism is also discussed. 相似文献
4.
5.
Leslie E. Chipman Benjamin B. Bederson Jennifer A. Golbeck 《Behaviour & Information Technology》2004,23(1):1-9
The SlideBar is a physical linear input device for absolute position control of 1° of freedom, consisting of a physical slider with a graspable knob positioned near or attached to the keyboard. Its range of motion is directly mapped to a one dimensional input widget such as a scrollbar. The SlideBar provides absolute position control in one dimension, is usable in the non-dominant hand in conjunction with a pointing device, and offers constrained passive haptic feedback. These characteristics make the device appropriate for the common class of tasks characterized by one-dimensional input and constrained range of operation. An empirical study of three devices (SlideBar, mouse controlled scrollbar, and mousewheel) shows that for common scrolling tasks, the SlideBar has a significant advantage over a standard mouse controlled scrollbar in user preference. In addition, users tended to prefer it over the mousewheel (without statistical significance). 相似文献
6.
7.
Albert Lamperti Alan Conger Leslie Delaney Marvin Sodicoff 《Drug development and industrial pharmacy》1994,20(12):1971-1989
ABSTRACT
Our transdermal permeation studies of radioprotectors in permeation-enhancing vehicles led us to hypothesize that radiation-induced hair loss could be reduced by topical application of radioprotectors. In the present study we used a hair regrowth assay in “plucked” mice to measure the radioprotective effectiveness of WR-1065, cysteine and TEMPOL when they were dissolved in a variety of vehicles, i.e., saline, dimethyl formamide (DMF), propylene glycol (PG), dimethyl sulfoxide (DMSO), ethanol. Protector effectiveness varied with radiation dose and vehicles. At 600 R, WR-1065 or cysteine, in any vehicle, reduced radiation-induced baldness scores; at 800 R, only WR-1065 in DMF and cysteine in saline, produced some protection. TEMPOL in ethanol produced protection at both the 600 and 800 R. Results suggest that suitably chosen topical application of protector/vehicle combinations can reduce radiation-induced hair loss. 相似文献
Our transdermal permeation studies of radioprotectors in permeation-enhancing vehicles led us to hypothesize that radiation-induced hair loss could be reduced by topical application of radioprotectors. In the present study we used a hair regrowth assay in “plucked” mice to measure the radioprotective effectiveness of WR-1065, cysteine and TEMPOL when they were dissolved in a variety of vehicles, i.e., saline, dimethyl formamide (DMF), propylene glycol (PG), dimethyl sulfoxide (DMSO), ethanol. Protector effectiveness varied with radiation dose and vehicles. At 600 R, WR-1065 or cysteine, in any vehicle, reduced radiation-induced baldness scores; at 800 R, only WR-1065 in DMF and cysteine in saline, produced some protection. TEMPOL in ethanol produced protection at both the 600 and 800 R. Results suggest that suitably chosen topical application of protector/vehicle combinations can reduce radiation-induced hair loss. 相似文献
8.
Voucher-based reinforcement therapy (VBRT) is an effective drug abuse treatment, but the cost of VBRT rewards has limited its dissemination. Obtaining VBRT incentives through donations may be one way to overcome this barrier. Two direct mail campaigns solicited donations for use in VBRT for pregnant, postpartum, and parenting drug users in Toronto, Ontario, Canada, and in Los Angeles, California. In Toronto, 19% of those contacted over 2 months donated $8,000 ($4,000/month) of goods and services. In Los Angeles, nearly 26% of those contacted over 34 months donated $161,000 ($4,472/month) of goods and services. Maintaining voucher programs by soliciting donations is feasible and sustainable. The methods in this article can serve as a guide for successful donation solicitation campaigns. Donations offer an alternative for obtaining VBRT rewards for substance abuse treatment and may increase its dissemination. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
L. Berkowitz and E. Harmon-Jones (see record 2004-15096-001) challenge appraisal theories of emotion by describing 2 sets of conditions (physical discomfort and anger-related muscle actions) in which anger appears to be elicited in the absence of theoretically predicted appraisals. In response, the authors discuss the ability of the specific appraisal model they have developed (e.g., C. A. Smith & L. D. Kirby, 2000, 2001; C. A. Smith & R. S. Lazarus, 1990) to account for such instances of anger. First, a number of issues are clarified relevant to the authors' model, including the nature of both the cognitive operations underlying appraisal and the specific appraisals hypothesized to evoke anger. The authors then describe how their model can account for the instances of anger described by L. Berkowitz and E. Harmon-Jones and how both accounts might be tested. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Four experiments examined 10-mo-old infants' causal event perception. Exp 1 replicated previous studies except that the specific objects used as agent and recipient varied from trial to trial. Under these conditions infants did not process the causality. Instead they keyed on specific temporal and spatial differences among the events. Exp 2 showed that infants notice a change in the particular agent performing either a causal or noncausal action. Exp 3 showed that infants do not notice a change in the type of action done to a particular recipient. Exp 4 demonstrated that infants do not pay attention to the object used as a recipient. As a whole, the results indicate that 10-mo-old infants perceive the causality of simple events by associating a specific agent with the causal action. These results provide more support for an information-processing view than for the view that infants have a causal module. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献