全文获取类型
收费全文 | 286篇 |
免费 | 12篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 55篇 |
机械仪表 | 1篇 |
建筑科学 | 8篇 |
矿业工程 | 1篇 |
能源动力 | 6篇 |
轻工业 | 13篇 |
水利工程 | 3篇 |
石油天然气 | 2篇 |
无线电 | 36篇 |
一般工业技术 | 39篇 |
冶金工业 | 44篇 |
自动化技术 | 89篇 |
出版年
2023年 | 2篇 |
2022年 | 12篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 9篇 |
2013年 | 18篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 10篇 |
2009年 | 22篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有301条查询结果,搜索用时 171 毫秒
71.
72.
Argues that strategy fills a real need in psychotherapeutic thinking. An attempt is made to define strategic rules for (1) choosing and defining goals, (2) locating strategic points, (3) actively searching for the client's responses, (4) dealing with resistance, (5) exploiting or creating propitious timings, (6) mobilizing allies, (7) concentrating the therapeutic influence, (8) stabilizing partial achievements, (9) dealing with competing demands, (10) retreating after failure, and (11) changing the therapeutic framework when needed. Each principle is illustrated by interventions from different therapeutic orientations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
73.
74.
V Serre W Dolci E Schaerer L Scrocchi D Drucker S Efrat B Thorens 《Canadian Metallurgical Quarterly》1998,139(11):4448-4454
The effect of exendin-(9-39), a described antagonist of the glucagon-like peptide-1 (GLP-1) receptor, was evaluated on the formation of cAMP- and glucose-stimulated insulin secretion (GSIS) by the conditionally immortalized murine betaTC-Tet cells. These cells have a basal intracellular cAMP level that can be increased by GLP-1 with an EC50 of approximately 1 nM and can be decreased dose dependently by exendin-(9-39). This latter effect was receptor dependent, as a beta-cell line not expressing the GLP-1 receptor was not affected by exendin-(9-39). It was also not due to the endogenous production of GLP-1, because this effect was observed in the absence of detectable preproglucagon messenger RNA levels and radioimmunoassayable GLP-1. Importantly, GSIS was shown to be sensitive to this basal level of cAMP, as perifusion of betaTC-Tet cells in the presence of exendin-(9-39) strongly reduced insulin secretion. This reduction of GSIS, however, was observed only with growth-arrested, not proliferating, betaTC-Tet cells; it was also seen with nontransformed mouse beta-cells perifused in similar conditions. These data therefore demonstrated that 1) exendin-(9-39) is an inverse agonist of the murine GLP-1 receptor; 2) the decreased basal cAMP levels induced by this peptide inhibit the secretory response of betaTC-Tet cells and mouse pancreatic islets to glucose; 3) as this effect was observed only with growth-arrested cells, this indicates that the mechanism by which cAMP leads to potentiation of insulin secretion is different in proliferating and growth-arrested cells; and 4) the presence of the GLP-1 receptor, even in the absence of bound peptide, is important for maintaining elevated intracellular cAMP levels and, therefore, the glucose competence of the beta-cells. 相似文献
75.
OBJECTIVE: The aim of this study was to examine the psychological effects, well-being and side effects after various doses of oral midazolam medication. METHODS: After informed consent has been obtained and following the approval by the institutional ethical committee, 80 adult patients in the ASA physical status I and II were randomly assigned to one of five different premedication groups: 3.75, 7.5, 11.25, 15 mg midazolam, and placebo. The medication was given in a double-blind fashion 60 min before induction of general anaesthesia for various surgical procedures. At 3 definite stages (before premedication, 30 and 60 min after premedication), blood pressure, heart rate, transcutaneous oxygen saturation and respiratory rate were measured. Sedation and well-being were graded according to a 5-point scale, and the subjective anxiety level was assessed according a visual analogue scale (range 0-100 mm). Anterograde and retrograde amnesia were measured by recall of auditive and visual stimuli. Finally, patients were asked whether in case of future surgery they would prefer the same or a different medication. RESULTS: Demographic data were similar in all groups. There was no significant difference in respiratory rate, oxygen saturation, blood pressure or heart rate. Alertness declined only after 60 min in the groups treated with 7.5 mg and more midazolam. During the entire measurement period, anxiolysis was not different from placebo in any of the midazolam groups. In comparison to placebo, all midazolam groups showed a statistically significant and dose dependent anterograde amnesia for visual stimuli. Subjective well-being scores showed no differences between the groups. Only few side effects were seen following doses of 7.5 mg and higher, including ptosis, strabismus, diplopia, speech disorders, disorientation and vertigo. The majority of patients in all groups indicated a wish for the same medication in case of future anaesthesia for surgical interventions. CONCLUSIONS: Midazolam administered orally prior to surgical procedures showed marked interindividual variability. Sedation and amnesia were dose-dependent and were evaluated by the patients as acceptable. Anxiolysis was not significantly different from placebo. A dose of 7.5 mg midazolam showed the best relation between desirable and undesirable effects. Adequate attention given to the patient by the anaesthesiologist prior to surgery seems to be as important and beneficial as oral medication with midazolam. 相似文献
76.
We present a method to derandomizeRNC algorithms, converting them toNC algorithms. Using it, we show how to approximate a class of NP-hard integer programming problems inNC, to within factors better than the current-bestNC algorithms (of Berger and Rompel and Motwaniet al.); in some cases, the approximation factors are as good as the best-known sequential algorithms, due to Raghavan. This class
includes problems such as global wire-routing in VLSI gate arrays and a generalization of telephone network planning in SONET
rings. Also for a subfamily of the “packing” integer programs, we provide the firstNC approximation algorithms; this includes problems such as maximum matchings in hypergraphs, and generalizations. The key to
the utility of our method is that it involves sums ofsuperpolynomially many terms, which can however be computed inNC; this superpolynomiality is the bottleneck for some earlier approaches, due to Berger and Rompel and Motwaniet al.
A preliminary version of this work appeared inProc. International Colloquim on Automata, Languages and Programming, 1996, pages 562–573.
Work done in parts at DIMACS (supported in part by NSF-STC91-19999 and by support from the N.J. Commission on Science and
Technology), at the Institute for Advanced Study, Princeton (supported in part by Grant 93-6-6 of the Alfred P. Sloan Foundation),
and at the National University of Singapore. 相似文献
77.
Maryam Tadayon Osnat Younes‐Metzler Yaniv Shelef Paul Zaslansky Alon Rechels Alex Berner Emil Zolotoyabko Friedrich G. Barth Peter Fratzl Benny Bar‐On Yael Politi 《Advanced functional materials》2020,30(32)
In the absence of minerals as stiffening agents, insects and spiders often use metal‐ion cross‐linking of protein matrices in their fully organic load‐bearing “tools.” In this comparative study, the hierarchical fiber architecture, elemental distribution, and the micromechanical properties of the manganese‐ and calcium‐rich cuticle of the claws of the spider Cupiennius salei, and the Zn‐rich cuticle of the cheliceral fangs of the same animal are analyzed. By correlating experimental results to finite element analysis, functional microstructural and compositional adaptations are inferred leading to remarkable damage resilience and abrasion tolerance, respectively. The results further reveal that the incorporation of both zinc and manganese/calcium correlates well with increased biomaterial's stiffness and hardness. However, the abrasion‐resistance of the claw material cross‐linked by incorporation of Mn/Ca‐ions surpasses that of many other non‐mineralized biological counterparts and is comparable to that of the fang with more than triple Zn content. These biomaterial‐adaptation paradigms for enhanced wear‐resistance may serve as novel design principles for advanced, high‐performance, functional surfaces, and graded materials. 相似文献
78.
Kyle L. Naughton Long Phan Erica M. Leung Rylan Kautz Qiyin Lin Yegor Van Dyke Benedetta Marmiroli Barbara Sartori Andy Arvai Sheng Li Michael E. Pique Mahan Naeim Justin P. Kerr Mercedeez J. Aquino Victoria A. Roberts Elizabeth D. Getzoff Chenhui Zhu Sigrid Bernstorff Alon A. Gorodetsky 《Advanced materials (Deerfield Beach, Fla.)》2016,28(38):8405-8412
79.
Bioinspired Films: Self‐Assembly of the Cephalopod Protein Reflectin (Adv. Mater. 38/2016)
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kyle L. Naughton Long Phan Erica M. Leung Rylan Kautz Qiyin Lin Yegor Van Dyke Benedetta Marmiroli Barbara Sartori Andy Arvai Sheng Li Michael E. Pique Mahan Naeim Justin P. Kerr Mercedeez J. Aquino Victoria A. Roberts Elizabeth D. Getzoff Chenhui Zhu Sigrid Bernstorff Alon A. Gorodetsky 《Advanced materials (Deerfield Beach, Fla.)》2016,28(38):8553-8553
80.
We present a verb–complement dictionary of Modern Hebrew, automatically extracted from text corpora. Carefully examining a large set of examples, we defined ten types of verb complements that cover the vast majority of the occurrences of verb complements in the corpora. We explored several collocation measures as indicators of the strength of the association between the verb and its complement. We then used these measures to automatically extract verb complements from corpora. The result is a wide-coverage, accurate dictionary that lists not only the likely complements for each verb, but also the likelihood of each complement. We evaluated the quality of the extracted dictionary both intrinsically and extrinsically. Intrinsically, we showed high precision and recall on randomly (but systematically) selected verbs. Extrinsically, we showed that using the extracted information is beneficial for two applications, prepositional phrase attachment disambiguation and Arabic-to-Hebrew machine translation. 相似文献