全文获取类型
收费全文 | 537篇 |
免费 | 23篇 |
专业分类
电工技术 | 2篇 |
综合类 | 2篇 |
化学工业 | 211篇 |
金属工艺 | 7篇 |
机械仪表 | 9篇 |
建筑科学 | 44篇 |
矿业工程 | 2篇 |
能源动力 | 3篇 |
轻工业 | 93篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 9篇 |
一般工业技术 | 80篇 |
冶金工业 | 29篇 |
原子能技术 | 2篇 |
自动化技术 | 63篇 |
出版年
2023年 | 4篇 |
2022年 | 18篇 |
2021年 | 32篇 |
2020年 | 12篇 |
2019年 | 11篇 |
2018年 | 11篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 22篇 |
2014年 | 16篇 |
2013年 | 34篇 |
2012年 | 37篇 |
2011年 | 38篇 |
2010年 | 21篇 |
2009年 | 19篇 |
2008年 | 26篇 |
2007年 | 36篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 14篇 |
2003年 | 8篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 18篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有560条查询结果,搜索用时 0 毫秒
51.
Wolfgang Bauer Tanja Ossiander Birgit Weber 《Frontiers of Chemical Science and Engineering》2018,12(3):400-408
The synthesis of new Schiff base-like ligands with asymmetric substituents pattern and their iron complexes with pyridine as axial ligand is described. Two of the ligands and one of the iron(II) complexes were characterized by single crystal X-ray structure analysis. One of the the iron(II) complexes shows spin crossover behavior while the others remain in the high spin state. The influence of the reduced symmetry of the ligand on the properties of the complexes is discussed. 相似文献
52.
Birgit Köhn Prof. Dr. Michael Kovermann 《Chembiochem : a European journal of chemical biology》2019,20(6):759-763
In all intracellular processes, protein structure and dynamics are subject to the influence of macromolecular crowding (MC). Here, the impact of MC agents of different types and sizes on the model protein Bacillus subtilis Cold shock protein B (BsCspB) during both thermal and chemical denaturation have been comprehensively investigated. We consistently reveal a distinct stabilization of BsCspB in a manner dependent on the MC concentration but not on viscosity, polarity, or size of the MC agent used. This general stabilization has been decoded by use of NMR spectroscopy, through monitoring of chemical shift (CS) perturbations and the intramolecular hydrogen-bonding networks, as well as local protection of amide protons against exchange with solvent protons. Whereas CSs and hydrogen-bonding networks are not systematically affected in the presence of MC, we detected a pronounced reduction in exchange in loop regions of BsCspB. We conclude that this reduced accessibility of solvent protons is a key parameter for the increases in protein stability seen under MC. 相似文献
53.
Sobha Karuthedom George Lucia Laukov Ren Weiss Vladislav Semak Birgit Fendl Victor U. Weiss Stephanie Steinberger Günter Allmaier Carla Tripisciano Viktoria Weber 《International journal of molecular sciences》2021,22(8)
Growing interest in extracellular vesicles (EVs) has prompted the advancements of protocols for improved EV characterization. As a high-throughput, multi-parameter, and single particle technique, flow cytometry is widely used for EV characterization. The comparison of data on EV concentration, however, is hindered by the lack of standardization between different protocols and instruments. Here, we quantified EV counts of platelet-derived EVs, using two flow cytometers (Gallios and CytoFLEX LX) and nanoparticle tracking analysis (NTA). Phosphatidylserine-exposing EVs were identified by labelling with lactadherin (LA). Calibration with silica-based fluorescent beads showed detection limits of 300 nm and 150 nm for Gallios and CytoFLEX LX, respectively. Accordingly, CytoFLEX LX yielded 40-fold higher EV counts and 13-fold higher counts of LA+CD41+ EVs compared to Gallios. NTA in fluorescence mode (F-NTA) demonstrated that only 9.5% of all vesicles detected in scatter mode exposed phosphatidylserine, resulting in good agreement of LA+ EVs for CytoFLEX LX and F-NTA. Since certain functional characteristics, such as the exposure of pro-coagulant phosphatidylserine, are not equally displayed across the entire EV size range, our study highlights the necessity of indicating the size range of EVs detected with a given approach along with the EV concentration to support the comparability between different studies. 相似文献
54.
Susanna Schubert Sandra Heller Birgit L?ffler Ingo Sch?fer Martina Seibel Gaetano Villani Peter Seibel 《International journal of molecular sciences》2015,16(5):9850-9865
Human mitochondrial DNA (mtDNA) is located in discrete DNA-protein complexes, so called nucleoids. These structures can be easily visualized in living cells by utilizing the fluorescent stain PicoGreen®. In contrary, cells devoid of endogenous mitochondrial genomes (ρ0 cells) display no mitochondrial staining in the cytoplasm. A modified restriction enzyme can be targeted to mitochondria to cleave the mtDNA molecules in more than two fragments, thereby activating endogenous nucleases. By applying this novel enzymatic approach to generate mtDNA-depleted cells the destruction of mitochondrial nucleoids in cultured cells could be detected in a time course. It is clear from these experiments that mtDNA-depleted cells can be seen as early as 48 h post-transfection using the depletion system. To prove that mtDNA is degraded during this process, mtDNA of transfected cells was quantified by real-time PCR. A significant decline could be observed 24 h post-transfection. Combination of both results showed that mtDNA of transfected cells is completely degraded and, therefore, ρ0 cells were generated within 48 h. Thus, the application of a mitochondrially-targeted restriction endonuclease proves to be a first and fast, but essential step towards a therapy for mtDNA disorders. 相似文献
55.
Nanocomposites gained more and more importance in the last few years because of their improved performance over the neat polymer matrix, that is, toughness and stiffness can be enhanced simultaneously by the addition of nanoparticles. However, the dispersion of these particles in the matrix remains a big challenge. In this study, two types of TiO2 nanoparticles were dispersed in two different epoxy resins by means of ultrasound. The particle size development in dependence on the dispersion time was investigated by dynamic light scattering for the different material systems. Furthermore, the influence of the viscosity on the sonication process' efficiency was analyzed. The resulting nanocomposites were tested for fracture and Charpy toughness. SEM images revealed that the improved fracture toughness properties are correlated to a rougher fracture surface, whose formation dissipates more energy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
56.
57.
Andrea Felgner Regina Schlink Peter Kirschenbühler Birgit Faas Heinz-Dieter Isengard 《Food chemistry》2008
In the field of food analysis, rapid measurements and results are generally of high importance. The Karl Fischer titration (KFT), a chemical method for determining water content, and its automated performance enhance rapidity by giving the opportunity to deal with more samples in less time; automated sequences can include different determination methods and sample treatments. Moreover, automation can improve reproducibility and precision. 相似文献
58.
Wendy Hollands Gary M. Brett Pauline Radreau Shikha Saha Birgit Teucher Richard N. Bennett Paul A. Kroon 《Food chemistry》2008
Blackcurrant (BC) fruits are a rich source of biologically active anthocyanins but little is known of the anthocyanin content of commonly consumed BC products or how processing affects the absorption. We report that whereas fresh and frozen whole BC were a rich source of anthocyanins, containing 897 and 642 mg (100 g FW)−1 of total anthocyanins the levels in all other products were substantially lower (0.05–10.3% of the levels in fresh fruit). Further, when the absorption and excretion of BC was assessed in volunteers consuming a portion (100 g) of frozen whole BC (642 mg total anthocyanins) and, 300 g of a BC drink made by diluting concentrated syrup (33.6 mg total anthocyanins), only small quantities of BC anthocyanins were excreted in urine (fruit, 0.053 ± 0.022%; drink, 0.036 ± 0.043%; mean percent urinary yield ± SD) and they were not detected in plasma. These data indicate that fresh and frozen BC, but not processed products, are rich sources of anthocyanins but, regardless of the food source, these anthocyanins are poorly bioavailable. 相似文献
59.
60.
Birgit Palm Jürgen G. Heinrich Joachim Reuer 《International Journal of Applied Ceramic Technology》2010,7(2):226-234
The essential influences of 15 parameters on defects (cracks and bubbles) during production of tableware have been studied with 16 experimental progressions using a L16(215) experimental design by G. Taguchi. Evaluation (analysis of means and analysis of variance) indicated that in this production liter weight, drying time, moisture before biscuit firing, and position in the biscuit-firing kiln have a significant influence on cracks. Concerning bubbles, parameters with an influence are liter weight, gate system, mold material, and moisture content before glost firing. Rejects of the article used in the experiments were reduced from 2.44% to 2.27% with respect to cracks and from 6.22% to 0% with respect to bubbles. 相似文献