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   511篇
  免费   2篇
  国内免费   1篇
电工技术   18篇
化学工业   26篇
金属工艺   6篇
机械仪表   16篇
建筑科学   9篇
能源动力   9篇
轻工业   247篇
水利工程   1篇
石油天然气   1篇
无线电   23篇
一般工业技术   77篇
冶金工业   5篇
原子能技术   10篇
自动化技术   66篇
  2022年   5篇
  2021年   3篇
  2020年   5篇
  2019年   5篇
  2018年   13篇
  2017年   6篇
  2016年   10篇
  2015年   5篇
  2014年   10篇
  2013年   155篇
  2012年   19篇
  2011年   23篇
  2010年   11篇
  2009年   8篇
  2008年   9篇
  2007年   6篇
  2006年   12篇
  2005年   9篇
  2004年   3篇
  2003年   6篇
  2002年   2篇
  2001年   3篇
  2000年   6篇
  1999年   7篇
  1998年   14篇
  1997年   17篇
  1996年   8篇
  1995年   8篇
  1994年   7篇
  1993年   7篇
  1992年   2篇
  1991年   11篇
  1990年   5篇
  1989年   11篇
  1988年   10篇
  1987年   9篇
  1986年   3篇
  1985年   9篇
  1984年   7篇
  1983年   4篇
  1982年   2篇
  1981年   4篇
  1980年   6篇
  1979年   6篇
  1978年   5篇
  1977年   3篇
  1976年   3篇
  1975年   3篇
  1972年   2篇
  1971年   2篇
排序方式: 共有514条查询结果,搜索用时 15 毫秒
61.
The effect of reducing dough pH to 4.2 and addition of 2–4% gluten on rheological and pasting properties of sound and sprouted wheat flours are reported. Baking properties studied using "Medium Time Fermentation" and "Short Time Fermentation" methods revealed that an acceptable bread could be produced from even highly sprouted wheat by lowering the pH and adding 4% vital gluten to the flour, and using the "Short Time Fermentation Method".  相似文献   
62.
The ultraviolet (UV), visible and near-infrared (NIR) absorption changes in corn oil were measured during processes simulating deep fat frying. Corn oil, maintained at 185C, was exposed to various treatments with nitrogen, air, water injection, air with water injection, and steam. Autoxidation due to a combination of air and high temperature in the simulated frying trials caused visible absorption changes between 400 and 580 nm as the oil deteriorated similar to those observed in potato frying experiments. These absorption changes were found to be associated with changes in an ultraviolet absorption band with a maximum near 270 nm. Second-derivative calibration equations developed at various visible and NIR absorption wavelengths successfully predicted the percentage of total polar materials (%TPM) which accumulated in the corn oil during simulated trials of autoxidation (R values from 0.93 to 0.98). Using spectral data from repetitive potato frying experiments, the predicted %TPM calculated with these equations correlated well with kinematic viscosity measurements (R values from 086 to 0.97).  相似文献   
63.
64.
65.
A model is presented to explain the strength-grain size behavior of ceramics exhibiting duplex microstructures and of ceramics with uniform coarse-grained microstructures. Using an energy balance analysis, the model shows that in most ceramics an hitiipl flaw contained within a single large grain will initially propagate and then arrest after entering the region of increased fracture-surface energy. The arrested flaw will subsequently propagate to failure at the value OF the critical stress intensity factor. Using the data in the literature, a strength-(grain size)−1/2 plot for MgAl2O4 was generated.  相似文献   
66.
67.
Selected nitrosoguanidine (NTG) mutants of Lactobacillus bulgaricus and L. casei produced appreciably higher acidities and a noticeable increase in proteolytic activity as compared to the parent cultures. Combination of these NTG-induced mutants with Streptococcus lactis and S. cremoris showed enhancement in the biochemical performance, thereby exploring the possibility of utilizing these variants in the manufacture of milk products.  相似文献   
68.
69.
Background and Aims: Taint in smoke‐exposed grapes have been associated with elevated levels of guaiacol and 4‐methylguaiacol. Previous research has reported guaiacol and 4‐methylguaiacol in both fruits and wines. In some cases, these compounds were not detected, or were detected at low levels in the fruit while high levels were subsequently identified during or after winemaking. Later research indicated that this was due to the presence of glycosidic conjugates. Here we report a method for the routine analysis of guaiacol and 4‐methylguaiacol released after acid hydrolysis of glycoside precursors. Methods and Results: Chardonnay, Merlot, Shiraz, Sangiovese and Cabernet Sauvignon fruits were collected following bushfire events in 2006–2007 in the King Valley wine region of NE Victoria, Australia. Gas chromatography‐mass spectrometry (GC‐MS) was used to detect free guaiacol and 4‐methylguaiacol in both fruits and wines. Low levels of free and bound forms were present in fruit not exposed to smoke. Substantial levels of free guaiacol and 4‐methylguaiacol were detected in the wines made from the smoke‐affected fruits. These compounds increased during bottle storage. Acid hydrolysis of wines and berries resulted in a several‐fold increase in free guaiacol and 4‐methylguaiacol. Conclusions: The validated GC‐MS method is suitable for monitoring free and glycosidically bound guaiacol and 4‐methylguaiacol after acid hydrolysis in both fruits and wines. Acid hydrolysis of wines provided evidence that bound volatiles, most probably glycosidically, act as reserve for guaiacol and 4‐methylguaiacol, which are released during ageing of wines. Significance of the Study: This is the first study published in a refereed journal to demonstrate that smoke taint‐associated volatiles increase during ageing of wine and bound forms of guaiacol and 4‐methylguaiacol represent an aroma reserve for smoke taint in ageing/bottled wines.  相似文献   
70.
Photosynthesis is a fundamental process in biosciences and biotechnology that influences profoundly the research in other disciplines. In this paper, we focus on the characterization of fundamental components, present in pigment-protein complexes, in terms of their spectroscopic properties such as infrared spectra, nuclear magnetic resonance, as well as nuclear quadrupole resonance, which are of critical importance for many applications. Such components include chlorophylls and bacteriochlorophylls. Based on the density functional theory method, we calculate the main spectroscopic characteristics of these components for the Fenna-Matthews-Olson light-harvesting complex, analyze them and compare them with available experimental results. Future outlook is discussed in the context of current and potential applications of the presented results.  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