全文获取类型
收费全文 | 1123篇 |
免费 | 35篇 |
学科分类
工业技术 | 1158篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 30篇 |
2020年 | 21篇 |
2019年 | 17篇 |
2018年 | 16篇 |
2017年 | 30篇 |
2016年 | 38篇 |
2015年 | 21篇 |
2014年 | 36篇 |
2013年 | 66篇 |
2012年 | 59篇 |
2011年 | 73篇 |
2010年 | 47篇 |
2009年 | 57篇 |
2008年 | 57篇 |
2007年 | 40篇 |
2006年 | 45篇 |
2005年 | 31篇 |
2004年 | 29篇 |
2003年 | 29篇 |
2002年 | 27篇 |
2001年 | 24篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 60篇 |
1997年 | 41篇 |
1996年 | 20篇 |
1995年 | 12篇 |
1994年 | 24篇 |
1993年 | 23篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有1158条查询结果,搜索用时 15 毫秒
21.
The global oil market is experiencing a structural shift. Faced with a rapid price decline, large oil-producing countries had decided to protect their market share, with the hopes of permanently removing expensive supply from the market. Meanwhile, the ability of the US shale oil producers to respond quickly to positive price signals puts downward pressure on prices. On the demand side, advances in renewable technology and the continued effort to curb consumption of fossil fuel conspire to inhibit long-run growth.1 These factors suggest that the current down-cycle may continue for an extended period of time or even invoke another down-cycle. 相似文献
22.
23.
Catherine Lefranc-Millot Dominique Vercaigne-Marko Pascal Dhulster Bertrand Fertin Bernard Quinque Didier Guillochon 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,66(1):79-85
A method for the production of bovine colostral F(ab′)2 fragments at pilot-plant scale was developed. Optimum yield of immunoglobulins in colostral whey was obtained after rennet treatment of first milking colostrum. Pepsin digestion was carried out directly on the colostral whey at pH 3·8 for 4 h, which led to the complete digestion of immunoglobulins into F(ab′)2 fragments. Elimination of β-lactoglobulin, the main immunogenic protein, was achieved by anion exchange on Duolite A560 at pH 6·0. The preparation was diafiltered with a 5000 Da membrane and the retentate spray-dried. The powder obtained contained approximately 34% F(ab′)2 fragments, with an antibody activity three times higher than the initial colostrum. 相似文献
24.
This paper describes the synthesis of an oil-soluble colloidal calcium thiophosphate by a direct route. It consists of the reaction of calcium oxide or hydroxide with tetraphosphorus decasulphide and water in the presence of a surfactant such as a calcium alkylaryl sulphonate in an organic medium. Reaction and micellisation occurred simultaneously according to a one-step process. The product is characterised by a high calcium, phosphorus and sulphur content. The colloidal nature of the product has been confirmed by dialysis. The 31P-NMR spectrum showed signals characteristic of a blend of different calcium thiophosphates, plus calcium phosphate. The product could be defined as a core of different calcium (thio)phosphates surrounded by a calcium alkylaryl sulphonate shell, according to a reverse micelle type association in oil. This compound was evaluated as an antiwear additive in a 130 Neutral Solvent mineral oil by anti-wear and extreme-pressure four-ball tests. The extreme-pressure characteristics depend on the concentration of mineral colloidal core in oil. The antiwear properties are a function not only of the concentration, but also of the colloidal core/surfactant shell ratio. Thermogravimetric analysis of these colloidal species shows a weight loss in the 350°C to 450°C range, due to surfactant degradation. The further evolution of weight loss up to 900°C demonstrates the high thermal stability of the colloidal calcium (thio)phosphate core. 相似文献
25.
Application of ATR-FTIR for a rapid and simultaneous determination of sugars and organic acids in apricot fruit 总被引:1,自引:0,他引:1
Sylvie Bureau David Ruiz Maryse Reich Barbara Gouble Dominique Bertrand Jean-Marc Audergon Catherine M.G.C. Renard 《Food chemistry》2009
A simple, fast and accurate Fourier transform mid-infrared spectroscopy method was developed for simultaneously determining sugar and organic acid contents in apricot fruit slurries using the attenuated total reflectance. The potential of this method coupled with chemometric techniques based on partial least squares was assessed by comparison with currently used enzymatic determination of sucrose, glucose, fructose, malic acid and citric acid. Fruits of eight contrasted cultivars harvested at different ripening stages were used in this study and randomly divided in a calibration set (505 apricots) and in a validation set (252 apricots). The most suitable region was found in the range between 1500 and 900 cm−1. Good prediction performances were obtained (R2 ? 0.74 and RMSEP ? 18%). Results concerning the prediction of other quality traits such as firmness, skin colour, ethylene production, soluble solids content and titratable acidity were discussed. 相似文献
26.
Xavier Vanhoye Alexandre Janin Amandine Caillaud Antoine Rimbert Fabienne Venet Morgane Gossez Wieneke Dijk Oriane Marmontel Sverine Nony Charlotte Chatelain Christine Durand Pierre Lindenbaum Jennifer Rieusset Bertrand Cariou Philippe Moulin Mathilde Di Filippo 《International journal of molecular sciences》2022,23(8)
Hypobetalipoproteinemia is characterized by LDL-cholesterol and apolipoprotein B (apoB) plasma levels below the fifth percentile for age and sex. Familial hypobetalipoproteinemia (FHBL) is mostly caused by premature termination codons in the APOB gene, a condition associated with fatty liver and steatohepatitis. Nevertheless, many families with a FHBL phenotype carry APOB missense variants of uncertain significance (VUS). We here aimed to develop a proof-of-principle experiment to assess the pathogenicity of VUS using the genome editing of human liver cells. We identified a novel heterozygous APOB-VUS (p.Leu351Arg), in a FHBL family. We generated APOB knock-out (KO) and APOB-p.Leu351Arg knock-in Huh7 cells using CRISPR-Cas9 technology and studied the APOB expression, synthesis and secretion by digital droplet PCR and ELISA quantification. The APOB expression was decreased by 70% in the heterozygous APOB-KO cells and almost abolished in the homozygous-KO cells, with a consistent decrease in apoB production and secretion. The APOB-p.Leu351Arg homozygous cells presented with a 40% decreased APOB expression and undetectable apoB levels in cellular extracts and supernatant. Thus, the p.Leu351Arg affected the apoB secretion, which led us to classify this new variant as likely pathogenic and to set up a hepatic follow-up in this family. Therefore, the functional assessment of APOB-missense variants, using gene-editing technologies, will lead to improvements in the molecular diagnosis of FHBL and the personalized follow-up of these patients. 相似文献
27.
Sulaimon Idowu Paul P. Bertrand Anna K. Walduck 《International journal of molecular sciences》2022,23(5)
Gastric cancer represents a significant disease burden worldwide. The factors that initiate cancer are not well understood. Chronic inflammation such as that triggered by H. pylori infection is the most significant cause of gastric cancer. In recent years, organoid cultures developed from human and animal adult stem cells have facilitated great advances in our understanding of gastric homeostasis. Organoid models are now being exploited to investigate the role of host genetics and bacterial factors on proliferation and DNA damage in gastric stem cells. The impact of a chronic inflammatory state on gastric stem cells and the stroma has been less well addressed. This review discusses what we have learned from the use of organoid models to investigate cancer initiation, and highlights questions on the contribution of the microbiota, chronic inflammatory milieu, and stromal cells that can now be addressed by more complex coculture models. 相似文献
28.
Nicolas Mackiewicz Thomas Bark Bertrand Cao Jacques A. Delaire Didier Riehl Wai Li Ling Stéphanie Foillard Eric Doris 《Carbon》2011,49(12):3998-4003
We report the synthesis, characterization and optical limiting behavior of a nanohybrid built by grafting C60-fullerenes on carbon nanotubes (CNTs). The nonlinear optical limiting properties of the CNT-C60 complex were investigated at wavelengths where C60 does not absorb. We found that the nanohybrid had superior performances to those of CNTs and fullerenes, either taken individually or as a mixture. This enhanced optical limitation of the nanohybrid suggests not only cooperative but also synergistic effects between the two carbon forms. A mechanism involving higher excitonic states of the CNTs formed by Auger recombination of low energy excitons is proposed. 相似文献
29.
30.
Bertrand Matths 《European Journal of Lipid Science and Technology》1997,99(5):170-174
Different oilseeds, usable as renewable resources, are analyzed for their content of condensed tannins, glucosinolates, phytic acid and its degradation products as well as for sinapine, and the results are presented. Seeds of sunflower, flax, coriander, Euphorbia lagascae, iberic. dragon head, safflor, Camelina sativa, soy, mustard, hemp and rapeseeds are used. Apart from hemp, coriander and Euphorbia lagascae different cultivars or genotypes of each species are investigated. The variation of the results of each cultivar or genotype is shown. Tannins and phytic acid are found in different amounts in all oilseeds, whereas sinapine and glucosinolates are limited to seeds from species belonging to the plant family Brassicaceae. 相似文献