全文获取类型
收费全文 | 118篇 |
免费 | 6篇 |
专业分类
化学工业 | 35篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
能源动力 | 3篇 |
轻工业 | 19篇 |
无线电 | 6篇 |
一般工业技术 | 26篇 |
冶金工业 | 8篇 |
原子能技术 | 1篇 |
自动化技术 | 21篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2014年 | 2篇 |
2013年 | 8篇 |
2012年 | 5篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有124条查询结果,搜索用时 15 毫秒
11.
12.
Catherine Elgoyhen Annick De Paepe Laureme Laquerbe Vincent Lhoist Philippe Harlet 《国际钢铁研究》2005,76(7):532-538
In order to develop low alloy dual and multiphase high strength steels, CRM and Arcelor implemented the Howaq‐twice process in a continuous annealing line. This new equipment combines a slow primary cooling with a fast secondary cooling. Various cooling strategies were investigated in regard to microstructure and mechanical properties of low alloyed steels. Depending on the cooling rate and the quenching temperature, the microstructure varied between fully martensitic, ferritic‐martensitic, and ferritic‐martensitic‐bainitic. The associated tensile strengths reached from 720 to 1100 MPa. 相似文献
13.
Bernd Helber Cem O. Asma Yacine Babou Annick Hubin Olivier Chazot Thierry E. Magin 《Journal of Materials Science》2014,49(13):4530-4543
Future space exploration missions beyond Earth’s orbit, such as sample returns from Mars, will use ablative materials for the thermal protection system in order to shield the spacecraft from the severe heating during reentry. In this paper, we present the results of an elaborate test campaign on a lightweight carbon composite ablator with the aim of defining a procedure for material response characterization in a 1.2-MW inductively heated Plasmatron facility, suitable to reproduce the hypersonic flight boundary layer environment. Three different test gases were used, air, nitrogen, and argon, at surface temperatures exceeding 3300 K. A comprehensive experimental setup was developed including a nonintrusive technique to measure surface recession by means of a high-speed camera. Surface degradation was strongly test gas dependent, while mass loss was mainly driven by in-depth decomposition of phenolic resin. Emission spectroscopy helped us identify C2 as a product of dissociating hydrocarbons, as well as cyanogen, suggesting surface nitridation. Melt flow at the surface and silicon emission indicated degradation of the glass microspheres used as additional filler. In air plasma, oxidation was inferred to be the main mechanism for ablation. 相似文献
14.
Films of a plasticized random terpolymer were prepared by evaporation of solutions in several solvents. The glass transition temperatures of the films were determined and were found to follow the Fox's equation. Their tensile modulus, measured just below the glass transition temperature, was found to depend on the residual solvent content of the films. 相似文献
15.
16.
17.
Ruta J Ravelet C Grosset C Fize J Ravel A Villet A Peyrin E 《Analytical chemistry》2006,78(9):3032-3039
In this paper, we report the chiral resolution of arginine using an anti-arginine l-RNA aptamer chiral selector in partial-filling CE. The effects of the capillary temperature, sample load, and aptamer plug length on the enantiomeric separation were assessed. Very high chiral resolving capability was observed at low or moderate capillary temperatures (the target peak being not detected in the separation window), whereas the practical chiral resolution was achieved only at high enough temperatures (50-60 degrees C). Over this high-temperature range, the electrophoretic behavior of the target enantiomer appeared to result from a combination of binding site heterogeneity, slow desorption kinetics, and concentration overload of aptamer binding sites. From additional thermal UV melting experiments, three RNA conformations were identified for the 50-60 degrees C temperatures. It was suggested that the presence of these different RNA conformations was a plausible source of the binding site heterogeneity. 相似文献
18.
Prediction of the antigenic sites of the cystic fibrosis transmembrane conductance regulator protein by molecular modelling 总被引:1,自引:0,他引:1
Gallet Xavier; Benhabiles Nora; Lewin Miguel; Brasseur Robert; Thomas-Soumarmon Annick 《Protein engineering, design & selection : PEDS》1995,8(8):829-834
Antibodies are powerful tools for studying the in situ localizationand physiology of proteins. The prediction of epitopes by molecularmodelling has been used successfully for the papilloma virus,and valuable antibodies have been raised [Muller et aL (1990)J. Gen. Virol, 71, 27092717]. We have improved the modellingapproach to allow us to predict epitopes from the primary sequencesof the cystic fibrosis transmembrane conductance regulator.The procedure involves searching for fragments of primary sequenceslikely to make amphipathic secondary structures, which are hydrophilicenough to be at the surface of the folded protein and thus accessibleto antibodies. Amphipathic helices were predicted using themethods of Berzofsky, Eisenberg and Jahnig. Their hydrophobichydrophilicinterface was calculated and drawn, and used to predict theorientation of the helices at the surface of the native protein.Amino acids involved in turns were selected using the algorithmof Eisenberg. Tertiary structures were calculated using FOLDING,a software developed by R.Brasseur for the prediction of smallprotein structures [Brasseur (1995) J. MoL Graphics, in press].We selected sequences that folded as turns with at least fiveprotruding polar residues. One important property of antibodiesis selectivity. To optimize the selectivity of the raised antibodies,each sequence was screened for similarity (FASTA) to the proteinsequences from several databanks. Ubiquitous sequences werediscarded. This approach led to the identification of 13 potentialepitopes in the cystic fibrosis transmembrane conductance regulator:seven helices and six loops. 相似文献
19.
Replacing the ({beta}{alpha})-unit 8 of E.coli TIM with its chicken homologue leads to a stable and active hybrid enzyme 总被引:2,自引:0,他引:2
Mainfroid Veronique; Goraj Karine; Rentier-Delrue Francoise; Houbrechts Annick; Noble Martin E.M.; Borchert Torben V.; Wierenga Rik K.; Martial Joseph A. 《Protein engineering, design & selection : PEDS》1993,6(8):893-900
In order to investigate how structural modifications interferewith protein stability, we modified a (ß)-unit inE.coli triosephosphate isomerase (TIM), a typical (ß)-barrelprotein, assuming that the pseudosymmetrical ß-barrelcan be divided into eight successive loop/ß-strand/loop/-helixmotifs. We replaced the eighth (ß)-unit of E.coliTIM with the corresponding chicken (ß)-unit. The substitution,involving the replacement of 10 of the 23 residues of this (ß)-unit, was evaluated first by modelling, then experimentally.Modelling by bomology suggests how the amino add replacementsmight be accommodated in the hybrid E.coli/chicken TIM (ETCM8CHI).Both natural and hybrid recombinant TIMs, overproduced in E.coli,were purified to homogeneity and characterized as to their stabilityand kinetics. Our kinetic studies show that the modificationperformed here leads to an active enzyme. The stability studiesindicate that the stability of ETIM8CHI is comparable to thatof the wild type TIM. 相似文献
20.
Retrieval of pigment concentrations and size structure of algal populations from their absorption spectra using multilayered perceptrons 总被引:2,自引:0,他引:2
Bricaud A Mejia C Blondeau-Patissier D Claustre H Crepon M Thiria S 《Applied optics》2007,46(8):1251-1260
Spectral absorption coefficients of phytoplankton can now be derived, under some assumptions, from hyperspectral ocean color measurements and thus become accessible from space. In this study, multilayer perceptrons have been developed to retrieve information on the pigment composition and size structure of phytoplankton from these absorption spectra. The retrieved variables are the main pigment groups (chlorophylls a, b, c, and photosynthetic and nonphotosynthetic carotenoids) and the relative contributions of three algal size classes (pico-, nano-, and microphytoplankton) to total chlorophyll a. The networks have been trained, tested, and validated using more than 3,700 simultaneous absorption and pigment measurements collected in the world ocean. Among pigment groups, chlorophyll a is the most accurately retrieved (average relative errors of 17% and 16% for the test and validation data subsets, respectively), while the poorest performances are found for chlorophyll b (average relative errors of 51% and 40%). Relative contributions of algal size classes to total chlorophyll a are retrieved with average relative errors of 19% to 33% for the test subset and of 18% to 47% for the validation subset. The performances obtained for the validation data, showing no strong degradation with respect to test data, suggest that these neural networks might be operated with similar performances for a large variety of marine areas. 相似文献