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   387篇
  免费   41篇
电工技术   2篇
化学工业   64篇
金属工艺   10篇
机械仪表   16篇
建筑科学   6篇
能源动力   26篇
轻工业   101篇
水利工程   6篇
石油天然气   1篇
无线电   24篇
一般工业技术   111篇
冶金工业   4篇
原子能技术   1篇
自动化技术   56篇
  2024年   3篇
  2023年   14篇
  2022年   26篇
  2021年   46篇
  2020年   22篇
  2019年   26篇
  2018年   23篇
  2017年   29篇
  2016年   22篇
  2015年   13篇
  2014年   18篇
  2013年   34篇
  2012年   21篇
  2011年   21篇
  2010年   22篇
  2009年   10篇
  2008年   13篇
  2007年   7篇
  2006年   2篇
  2005年   4篇
  2004年   4篇
  2003年   4篇
  2002年   2篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   5篇
  1993年   3篇
  1992年   3篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   4篇
  1985年   1篇
  1984年   2篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
排序方式: 共有428条查询结果,搜索用时 15 毫秒
91.
92.
93.
Expanded snacks based on Moringa (Moringa oleifera) leaf powder (MLP) and oat flour were produced using a lab-scale twin-screw extruder. Four levels of MLP (0, 15, 30, and 45%, dry blend basis) and three levels of in-barrel moisture content (19, 22, and 26%, wet basis) were studied. Expansion of extrudates decreased as MLP level increased. On the other hand, expansion was positively affected by in-barrel moisture for all treatments with MLP. The role of MLP and in-barrel moisture in modifying phase transition, water binding, and gas-holding capacity of the extrusion melt was evaluated and related to product properties.  相似文献   
94.
Effect of Aqueous Enzymatic Processes on Sunflower Oil Quality   总被引:2,自引:0,他引:2  
The use of enzymes in aqueous vegetable oilseed extraction for simultaneous recovery of high quality oil and protein is gaining recognition. In the present work, five enzyme preparations [Protex 7L by Genencor (Rochester, NY USA), Alcalase 2.4L, and Viscozyme L by Novozymes (Bagsvaerd, Denmark), Natuzyme by Bioproton Pty Ltd (Australia) and Kemzyme by Kemin Europa N·V. (Belgium)] were studied to evaluate their effects on the extraction of oil and protein from sunflower seeds. Preliminary experiments were conducted for the selection of enzymes, optimum enzyme concentration, incubation time and pH. Maximum oil yield (87.25% of the total oil in the seed) was obtained with Viscozyme L, whereas, Protex 7L offered the highest level of protein in the aqueous phase. The comparison of the quality attributes of enzyme-assisted aqueous extracted (EAAE) oil with those of solvent-extracted and control (oils extracted without enzyme treatment) oils revealed no significant (> 0.05) variations for iodine value, density, refractive index, unsaponifiable matter, and fatty acid composition among the extraction methods. The control and EAAE oils also exhibited a better oxidation state. The tocopherol concentration for the oils, produced with the enzymes, was noted to be quite improved relative to the control and solvent-extracted oils. A higher antioxidant activity in terms of total phenolic contents, 2,2′-diphenyl-1-picrylhydrazyl scavenging capacity and inhibition of linoleic acid peroxidation was also observed for the EAAE oils as against control and the solvent-extracted oils.  相似文献   
95.
Abstract

This study presents an integrated water quantity and quality management method for the entire Yellow River system where the eco-environment has been deteriorating and water quantity is very scarce. The supply and demand of water resources has been investigated. The integration of the concepts of water resources functional capacity and water resources functional deficit have been put forward, and their characteristics have been analyzed. The results, based on 1997 to 1999 data, indicate that approximately 39 percent of the total river length was of excellent to good quality, 26 percent was moderate, and 35 percent was poor to very poor. The total natural runoffs of the river were 31.8, 43.9, and 43.4 billion m3, and about 94, 65, and 71 percent of them were withdrawn for agricultural, industrial, and domestic uses in 1997, 1998, and 1999, respectively. The total water resources availabilities were 21.1, 28.8, and 29.2 billion m3 occupying about 66, 66, and 67 percent of the total runoffs in 1997, 1998, and 1999, respectively. From 1997 to 1999, the river could provide only 53 percent (on average) of the total water resources demand for the uses and discharge to the Bohai Sea; about 57 percent of the water deficiency resulted from pollution and 43 percent from quantity deficit. For the main pollution parameter (COD Mn ), the averages of water resources functional capacity and deficit were 29,571.54 and 199.70 kg, respectively; for NH 4-N, the averages of water resources functional capacity and deficit were 3774.26 and 113.08 kg, respectively. These demonstrated that the influence of NH 4-N on water resources availability was more than that of COD Mn and that the functional capacity was much higher than functional deficit, suggesting that the actual water quality was mostly better than the required one for water supply functions.  相似文献   
96.
Control charts are essential tools to monitor the quality of a process and commonly used in many industries besides industrial production. Due to the industrial revolution, many products have very low failure chances and labeled as the high-quality products, where the time-between-events (TBE) charts are commonly used to monitor such processes. This study purposes control charts to monitor time and magnitude assuming the power law process for the TBE whereas the magnitude is assumed cumulative as well as noncumulative over time. Besides two illustrative examples, a comparison to the existing rate and first passage time (FPT) charts is also presented in this study. It is shown numerically that the proposed charts are more efficient than the existing FPT and rate charts.  相似文献   
97.
The palm oil mill effluent imposes environmental issues because of natural and supplement substance. This waste has a significant amount of biological oxygen demand, total suspended solids, chemical oxygen demand, and turbidity. Moringa oleifera seeds′ performance analysis as natural coagulants during the pretreatment stage of palm oil mill effluent before it is filtered through commercial nanofiltration membrane is the focus of the current study. The untreated palm oil mill effluent has 2,410 mg/L biological oxygen demand, 3,900 mg/L chemical oxygen demand, 865 NTU turbidity, 41,900 mg/L total suspended solids, and 4.61 pH. The significant reduction occurred in the feed parameters viz., 91.7 % for biological oxygen demand, 83.0 % for chemical oxygen demand, 67.7 % for total dissolved solids, and 72.8 % for turbidity after the pretreatment; however, the pH increased to 4.88. Design expert® was used to design the experiments and optimize the palm oil mill effluent pretreatment process via a one-factor experimental design. The optimized solution has a 0.994 desirability index. Finally, it was concluded that with ever-tightening environmental standards, moringa oleifera could provide a cheap, green, and potential natural alternative to the existing coagulants employed to treat the palm oil mill effluent.  相似文献   
98.
Novel antihypercholesterolemic bioactive peptides (BAP) from peptic camel whey protein hydrolysates (CWPH) were generated at different time, temperature, and enzyme concentration (%). Hydrolysates showed higher pancreatic lipase- (PL; except 3 CWPH) and cholesterol esterase (CE)-inhibiting potential, as depicted by lower half-maximal inhibitory concentration values (IC50 values) compared with nonhydrolyzed camel whey proteins (CWP). Peptide sequencing and in silico data depicted that most BAP from CWPH could bind active site of PL, whereas as only 3 peptides could bind the active site of CE. Based on higher number of reactive residues in the BAP and greater number of substrate binding sites, FCCLGPVPP was identified as a potential CE-inhibitory peptide, and PAGNFLPPVAAAPVM, MLPLMLPFTMGY, and LRFPL were identified as PL inhibitors. Molecular docking of selected peptides showed hydrophilic and hydrophobic interactions between peptides and target enzymes. Thus, peptides derived from CWPH warrant further investigation as potential candidates for adjunct therapy for hypercholesterolemia.  相似文献   
99.
Fish processing industries result in an ample number of protein-rich byproducts, which have been used to produce protein hydrolysate (PH) for human consumption. Chemical, microbial, and enzymatic hydrolysis processes have been implemented for the production of fish PH (FPH) from diverse types of fish processing byproducts. FPH has been reported to possess bioactive active peptides known to exhibit various biological activities such as antioxidant, antimicrobial, angiotensin-I converting enzyme inhibition, calcium-binding ability, dipeptidyl peptidase-IV inhibition, immunomodulation, and antiproliferative activity, which are discussed comprehensively in this review. Appropriate conditions for the hydrolysis process (e.g., type and concentration of enzymes, time, and temperature) play an important role in achieving the desired level of hydrolysis, thus affecting the functional and bioactive properties and stability of FPH. This review provides an in-depth and comprehensive discussion on the sources, process parameters, purification as well as functional and bioactive properties of FPHs. The most recent research findings on the impact of production parameters, bitterness of peptide, storage, and food processing conditions on functional properties and stability of FPH were also reported. More importantly, the recent studies on biological activities of FPH and in vivo health benefits were discussed with the possible mechanism of action. Furthermore, FPH-polyphenol conjugate, encapsulation, and digestive stability of FPH were discussed in terms of their potential to be utilized as a nutraceutical ingredient. Last but not the least, various industrial applications of FPH and the fate of FPH in terms of limitations, hurdles, future research directions, and challenges have been addressed.  相似文献   
100.
The intention of this review article is to review the knowledge about interactions in organic binary liquid mixtures. Molecular interactions in organic binary liquid mixtures are interesting due to their extensive use in many fields of solution chemistry. The thermodynamics of component molecules present in various systems interacting are particularly interesting because they display fantastic results. Studies of different organic liquid mixtures represent the different modes of interactions prevailing in the component molecules. The number of parameters required describing the properties of a given class of mixtures increases sharply with the number of segment types involved. In recent years, the theoretical and experimental investigations of interactions between unlike molecules have been conveniently carried out using excess thermodynamic functions. The properties of liquid mixtures depend on the forces between molecules and on the nature and volume of these molecules, and change with the composition of the mixtures. This change, in turn, is reflected in the thermodynamic properties of the mixtures. The influence of significant contributions of a chemical, physical and geometrical nature that change excess thermodynamic properties is considered and explained in detail.  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