首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   141篇
  免费   9篇
化学工业   50篇
建筑科学   8篇
矿业工程   1篇
能源动力   1篇
轻工业   41篇
水利工程   1篇
石油天然气   1篇
无线电   1篇
一般工业技术   18篇
冶金工业   7篇
自动化技术   21篇
  2023年   1篇
  2022年   12篇
  2021年   21篇
  2020年   6篇
  2019年   1篇
  2018年   10篇
  2017年   3篇
  2016年   2篇
  2015年   9篇
  2014年   3篇
  2013年   9篇
  2012年   15篇
  2011年   13篇
  2010年   4篇
  2009年   5篇
  2008年   9篇
  2007年   3篇
  2006年   3篇
  2004年   6篇
  2003年   5篇
  2002年   3篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
排序方式: 共有150条查询结果,搜索用时 15 毫秒
101.
We have fabricated anodic porous alumina from thin films (100/500 nm) of aluminium deposited on technological substrates of silicon/glass, and investigated the feasibility of this material as a surface for the development of analytical biosensors aiming to assess the status of living cells. To this goal, porous alumina surfaces with fixed pitch and variable pore size were analyzed for various functionalities. Gold coated (about 25 nm) alumina revealed surface enhanced Raman scattering increasing with the decrease in wall thickness, with factor up to values of approximately 104 with respect to the flat gold surface. Bare porous alumina was employed for micro-patterning and observation via fluorescence images of dye molecules, which demonstrated the surface capability for a drug-loading device. NIH-3T3 fibroblast cells were cultured in vitro and examined after 2 days since seeding, and no significant (P > 0.05) differences in their proliferation were observed on porous and non-porous materials. The effect on cell cultures of pore size in the range of 50–130 nm—with pore pitch of about 250 nm—showed no significant differences in cell viability and similar levels in all cases as on a control substrate. Future work will address combination of all above capabilities into a single device.  相似文献   
102.
103.
104.
105.
106.
In this paper a complete characterisation of four typical durum wheat breads produced in Italy was performed, from the starting semolinas to the final product, also considering the intermediate dough. An evaluation of the quality of durum wheat re-milled semolinas was carried out by means of routine investigations, together with nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS) analyses, that were also applied to dough ready for baking and bread to monitor the variations that occur during processing. The experimental data obtained from routine and spectroscopic determinations were investigated using multivariate statistical analysis to evaluate the possibility of differentiating flours, doughs and breads according to their geographical origin. Computerised image analysis was applied to quantify the crumb grain features of different bread types, and to try to characterise each bread type through a set of crumb morphological and colour parameters.  相似文献   
107.
In the quest of new, less hazardous, and more ambient-friendly froth flotation reagents, the use of biosolids or humic acids as both collector and frother for the concentration of copper sulphide ores was investigated. Rougher flotation tests were conducted in Denver cells on a laboratory scale, and metallurgical indicators such as copper recovery, copper concentrate grade, and concentration and enrichment ratios were compared with those obtained under similar conditions but using conventional collectors and frothers for the industrial flotation of copper sulphide ores. With a dosage of 10% (w/w) biosolids, copper recovery and grade were 26% and 0.81%, respectively. The copper recovery and grade obtained with 1.5% (w/w) salt of humic acids were 29.7% and 3.5%, respectively. A significantly higher copper recovery (65.1%) was obtained with conventional industrial collectors and frothers, but the grade was also low (3.1% Cu). With the same dosage of humic substances, humic acid show that the flotation rate constant was significantly higher (0.2 min−1) than that obtained with the same dosage of biosolids (0.09 min−1). These results indicate that humic acids have more affinity than biosolids for copper-containing mineral species, and also show that biosolids and humic acids could be used as both collector and frother in the sulphide mineral concentration process by froth flotation. Because the distribution of iron in the concentrate obtained with biosolids is highest, these materials seem to have more affinity for pyrite.  相似文献   
108.
The question if the "Brett character" is a favorable wine attribute is one of the most controversial issues and it is currently addressed by many researches. Actually, the presence of Brettanomyces/Dekkera in wine during barrel aging is often associated to detrimental organoleptic characteristics depending on the release of volatile phenols (for example, 4-ethylphenol and 4-ethylguaiacol); for that reason the possibility to rapidly detect the yeast at the early stage of wine production could allow preventive actions to reduce wine spoilage. In this work, 25 and 5 samples from conventional and organic vineyards, respectively, all suspected to be spoiled by Brettanomyces/Dekkera spp., were analyzed using both culture-dependent and culture-independent techniques. In particular, a DNA extraction protocol and a real-time quantitative PCR (qPCR) assay to directly detect and quantify B. bruxellensis were optimized. Results showed that B. bruxellensis was present in 22 of 30 samples, ranging from 10 to 10(4) CFU/mL, lower values being found in organic wines (10 to 10(2) CFU/mL). Overall, qPCR was proved to be a useful and valuable wine control system, since 12 samples were recorded as positive for yeast presence when analyzed by qPCR and negative in case of plate count analyses. Practical Application: Brettanomyces cells were detected using a qPCR method, optimized in this study, which allows to obtain results quickly.  相似文献   
109.
Equilibrium pressures of hydrogen chloride and water vapour over solid or liquid barium chloride have been measured between 1173 K and 1473 K. All other gases were excluded from the system. The corresponding equilibria were represented by the following reactions: BaCl2(s) + H2O(g) ? BaO(s) + 2 HCl(g), between 1173 K and 1235 K; BaCl2(1) + H20(g) ? BaO(s) + 2 HCl(g), between 1235 K and 1473 K; 32 BaCl2(1)(saturated with BaO) + H2O(g) ai 12 (BaCl2 2BaO)(s) + 2 HCl(g), between 1173 K and 1268 K; and 43 BaCl2(1) (saturated with BaO) + H2O(g) ? 13 (BaCl2. 3BaO)(s) + 2 HCl(g), between 1268 K and 1473 K. The equilibrium constants Kp fit satisfactorily a linear plot of In Kp versus reciprocal absolute temperature. Mean enthalpy and entropy values of the reactions studied in the temperature range investigated were obtained from the plot and compared to literature data and to the phase diagram of the barium chloride — barium oxide system. The reactions involved and the thermodynamics of reactivity of barium chloride with water are critically examined.  相似文献   
110.
Endometriosis is a gynecological condition affecting patients in reproductive age. The aim of this paper was to assess the effects of the autophagy and mitophagy induction in a rat model of endometriosis. Endometriosis was induced by the injection of uterine fragments, and rapamycin (0. 5 mg/kg) was administered once per week. One week from the induction, rats were sacrificed, and laparotomy was performed to collect the endometriotic implants and to further process them for molecular analysis. Western blot analysis was conducted on explanted lesions to evaluate the autophagy pathway during the pathology. Elevated phospho-serine/threonine kinase (p-AKT) and mammalian target of rapamycin (mTOR) expressions were detected in vehicle-treated rats, while Beclin and microtubule-associated protein 1A/1B-light chain 3 II (LC3II) expressions were low. Additionally, samples collected from vehicle groups indicated low Bnip3, Ambra1, and Parkin expressions, demonstrating impaired autophagy and mitophagy. Rapamycin administration reduced p-AKT and mTOR expressions and increased Beclin and LC3II, Bnip3, Ambra1, and Parkin expressions, activating both mechanisms. We also evaluated the impact of the impaired autophagy and mitophagy pathways on apoptosis and angiogenesis. Rapamycin was administered by activating autophagy and mitophagy, which increased apoptosis (assessed by Western blot analysis of Bcl-2, Bax, and Cleaved-caspase 3) and reduced angiogenesis (assessed by immunohistochemical analysis of vascular endothelial grow factor (VEGF) and CD34) in the lesions. All of these mechanisms activated by the induction of the autophagy and mitophagy pathways led to the reduction in the lesions’ volume, area and diameter.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号