全文获取类型
收费全文 | 617篇 |
免费 | 22篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 147篇 |
金属工艺 | 8篇 |
机械仪表 | 11篇 |
建筑科学 | 46篇 |
矿业工程 | 1篇 |
能源动力 | 18篇 |
轻工业 | 86篇 |
水利工程 | 5篇 |
无线电 | 27篇 |
一般工业技术 | 64篇 |
冶金工业 | 145篇 |
自动化技术 | 80篇 |
出版年
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 21篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 15篇 |
2017年 | 10篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 18篇 |
2013年 | 36篇 |
2012年 | 28篇 |
2011年 | 39篇 |
2010年 | 20篇 |
2009年 | 25篇 |
2008年 | 30篇 |
2007年 | 38篇 |
2006年 | 24篇 |
2005年 | 28篇 |
2004年 | 15篇 |
2003年 | 23篇 |
2002年 | 29篇 |
2001年 | 17篇 |
2000年 | 12篇 |
1999年 | 10篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
排序方式: 共有639条查询结果,搜索用时 359 毫秒
31.
32.
Richard K. Burdick Valerie Pferdeort Leslie Sidor Arun Tholudur 《Quality and Reliability Engineering International》2011,27(6):771-780
This paper provides a graphical approach for presenting results of a statistical test of average equivalence with process data. In addition, a graphical representation of process change in variance is presented. An example from the biopharmaceutical industry is provided to illustrate the information contained in the chart. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
33.
Meharg AA Pain DJ Ellam RM Baos R Olive V Joyson A Powell N Green AJ Hiraldo F 《The Science of the total environment》2002,300(1-3):81-86
White storks (Ciconia ciconia) fed in contaminated waters resulting from the Aznacollar acid mining-sludge spillage into the R. Guadiamar, which feeds the eastern flank of the Guadalquivir marshes (Do?ana), S.W. Spain. The sludge was rich in a range of toxic elements, and in organic pollutants such as the aromatic amines. Storks did not exhibit elevated metals in their blood immediately following the accident, but chick blood collected the year following the accident showed genotoxic damage compared to the controls. In this study lead isotope analysis was used to assess if the storks had ingested sludge-derived contaminants. The sludge lead isotope ratio was distinct from that of the Do?ana sediments. The stork blood lead isotope ratios exactly matched that of the sludge. It was concluded that the storks had ingested sludge-derived contaminants. A detailed study of the lead contamination along the R. Guadiamar and the R. Guadalquivir (of which the Guadiamar is a tributary) was also conducted to place the white stork colony lead exposure in the context of the spatial contamination of the storks' habitat. 相似文献
34.
Pichia sorbitophila grows rapidly in the presence of very high NaCl concentrations. Under these conditions, even when the K(+) concentration is low, P. sorbitophila cells can maintain low Na(+) and high K(+) contents. This remarkable capacity of P. sorbitophila fails when the external pH is not acidic. This indicates that Na(+) efflux is mediated by an electroneutral Na(+)/H(+) antiporter. We have cloned and sequenced two genes designated as PsNHA1 and PsNHA2, which probably encode two antiporters of this type. The genes present high similarity with the corresponding genes from other yeasts. The heterologous expression of PsNHA1 or PsNHA2 in a Saccharomyces cerevisiae mutant lacking the Na(+) efflux systems and sensitive to high concentrations of Na(+) and K(+) rescued the tolerance and the ability to extrude both cations. The Accession Nos of the sequenced DNA fragments are: PsNHA1, AJ496431; PsNHA2, AJ496432. (TC 2.A.36) Copyright 2002 John Wiley & Sons, Ltd. 相似文献
35.
Alonso DO An C Daggett V 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2002,360(1795):1165-1178
As computer power increases, so too does the range of interesting biomolecular phenomena and properties that can be simulated. It is now possible to simulate complicated protein conformational changes at ambient or physiological temperatures. In this regard, we are attempting to map the conformational transitions of the normal, cellular prion protein (PrP(C)) to its infectious scrapie isoform (PrP(Sc)), which causes neurodegenerative diseases in many mammals. These two forms have identical sequences and are conformational isomers, with heightened formation of beta-sheet structure in the scrapie form. Conversion can be triggered by lowering the pH, but thus far it has been impossible to characterize the conformational change at high resolution using experimental methods. Therefore, to investigate the effect of acidic pH on PrP conformation, we have performed molecular-dynamics simulations of hamster, human and bovine forms of the prion protein in water at neutral and low pH. In all cases the core of the protein is well maintained at neutral pH. At low pH, however, the protein is more dynamic, and the sheet-like structure increases both by lengthening of the native beta-sheet and by addition of a portion of the N-terminus to widen the sheet by another 2-3 strands. 相似文献
36.
Back JW Notenboom V de Koning LJ Muijsers AO Sixma TK de Koster CG de Jong L 《Analytical chemistry》2002,74(17):4417-4422
A new method is presented to screen proteolytic mass maps of cross-linked protein complexes for the presence of cross-linked peptides and for the verification of proposed structures. On the basis of the incorporation of 18O from isotopically enriched water into the C-termini of proteolytic peptides, cross-linked peptides are readily distinguished in mass spectra by a characteristic 8 amu shift. This is due to the incorporation of two 18O atoms in each C-terminus, so that normal and surface-labeled peptides shift 4 amu and cross-linked peptides containing two C-termini will shift 8 amu compared with their unlabeled counterparts. The method is fast, sensitive, and reliable and can be combined with any available cross-linking reagent and a wide range of proteolytic agents. As proof of principle, we successfully applied the method to a complex of two DNA repair proteins (Rad18-Rad6) and identified the interaction domain. 相似文献
37.
Despite training, professionals sometimes make serious errors in risky decision making. The authors investigated judgments and decisions for 9 hypothetical patients at 3 levels of cardiac risk, comparing student and physician groups varying in domain-specific knowledge. Decisions were examined regarding whether they deviated from guidelines, how risk perceptions and risk tolerances determined decisions, and how the latter differed for knowledge groups. More knowledgeable professionals were better at discriminating levels of risk according to external correspondence criteria but committed similar errors in disjunctive probability judgments, violating internal coherence criteria. Also, higher knowledge groups relied on fewer dimensions of information than did lower knowledge groups. Consistent with fuzzy-trace theory, experts achieved better discrimination by processing less information and made sharper all-or-none distinctions among decision categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
Stephen Roger A. Paolo Timothy I. Marco F. Valerie Alison 《Sensors and actuators. B, Chemical》2005,110(2):209-217
Alumina support material suitable for use as a planar automotive gas sensor support was coated in thin films of yttria-stabilised zirconia (YSZ) and titania. The morphology, composition, thickness and homogeneity of the coating was measured. The coating was applied to the ‘green’ form of a tape cast alumina substrate which was subsequently fired at 1500 °C to produce the final form of the coated alumina. The YSZ coating gave a continuous 5 μm thick coating with no evidence of mixed oxide formation between the YSZ and the alumina substrate. XRD indicated a face centred cubic Y doped ZrO2 or primitive tetragonal Zr0.9Y0.1O1.95 phase. The titania coatings were much thinner (<1 μm) with signs of trace amounts of aluminium titanium oxide (Al2TiO5) as well as rutile titania in XRD. Spot analysis using X-ray photoelectron spectroscopy showed a fairly regular titania coverage. Atomic force microscopy analysis showed a particle size of 1–3 μm for the YSZ coating and 0.5 μm for titania. 相似文献
39.
40.
Constructed the Children's Self-Efficacy for Peer Interaction Scale (CSPI) and administered it to 245 3rd–5th graders along with the Piers-Harris Children's Self-Concept Scale and the Teacher Rating Scale of Social Efficacy. Analyses of reliability and construct validity indicated that the CSPI has psychometric properties that warrant its use. Ss' self-efficacy varied by grade and situation. The usefulness of the CSPI for research on children's social development is discussed. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献