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   83篇
  免费   2篇
化学工业   14篇
金属工艺   1篇
机械仪表   1篇
建筑科学   5篇
能源动力   5篇
轻工业   33篇
无线电   1篇
一般工业技术   4篇
冶金工业   15篇
自动化技术   6篇
  2021年   2篇
  2020年   1篇
  2018年   1篇
  2016年   1篇
  2015年   1篇
  2013年   7篇
  2012年   3篇
  2011年   5篇
  2010年   5篇
  2009年   4篇
  2008年   5篇
  2007年   2篇
  2006年   5篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2002年   4篇
  2001年   1篇
  1998年   3篇
  1997年   6篇
  1996年   3篇
  1995年   4篇
  1994年   1篇
  1993年   1篇
  1990年   1篇
  1988年   2篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
  1970年   1篇
  1967年   1篇
  1962年   1篇
  1940年   1篇
排序方式: 共有85条查询结果,搜索用时 0 毫秒
51.
Methyl tallowate was prepared from edible beef tallow via transesterification, and was blended with ethanol and/or No.2 diesel fuel in different ratios. Crystallization characteristics of methyl tallowate and its blends were studied at temperatures ranging from 22 to −16°C. Blending ethanol with methyl tallowate reduced crystal formation at all temperatures. As the temperature of the blends was reduced from 22 to 0°C, there was no effect on crystal formation of saturated vs. unsaturated fatty acids. Below 0°C, the saturated fatty acids crystallized at a much faster rate than the unsaturated fatty acids.  相似文献   
52.
Self- and spouse ratings of anger and hostility were examined as predictors of coronary heart disease (CHD) in 185 cardiac patients. Patients completed the Multidimensional Anger Inventory (MAI) and the Marlowe-Crowne Social Desirability (MCSD) Scale; the MAI (rewritten to 3rd person) was completed by Ss' spouses or by a peer. Thallium scans were used to measure CHD status. Results show that patient-rated MAI scores were inversely correlated with MCSD. There were no gender differences for patient-rated MAI scores, but spouse ratings showed gender effects for Anger-Arousal and Hostile Outlook: Women rated their husbands higher than men rated their wives. Patients with positive thallium scans were no different from those without CHD on patient-rated MAI scores; however, spouse ratings indicated that those with CHD had higher Hostile Outlook and Anger-In scores. After accounting for the effects of traditional CHD risk factors, only spouse-rated hostility contributed significant incremental variance to the prediction of CHD status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
53.
Crude petroleum flows in the USSR for 1980 are modelled using the out-of-kilter algorithm. Constraints in the petroleum distribution network are identified was well as future problem areas, allowing the rationality of Soviet plans and policies with regard to the system to be evaluated. The main contraints in 1980 were in the European USSR, particularly in the older oil-producing areas, indicating that subsequent additions to the network in these areas have been warranted. Overall, the actual Soviet distribution of petroleum appears to be relatively efficient.  相似文献   
54.
55.
Reduction of fumonisin B₁ in corn grits by twin-screw extrusion   总被引:1,自引:0,他引:1  
Abstract: This study was designed to investigate the fate of fumonisins in flaking corn grits during twin‐screw extrusion by measuring fumonisin B1 (FB1) and its analogs with a mass balance approach. Food grade corn grits and 2 batches of grits contaminated with FB1 at 10 and 50 μg/g by Fusarium verticillioides M‐2552 were processed with or without glucose supplementation (10%, w/w) with a twin‐screw extruder. Extrusion reduced FB1 in contaminated grits by 64% to 72% without glucose and 89% to 94% with added glucose. In addition, extrusion alone resulted in 26% to 73% reduction in the levels of fumonisin B2 and fumonisin B3, while levels of both mycotoxins were reduced by >89% in extruded corn grits containing 10% glucose. Mass balance analysis showed that 38% to 46% of the FB1 species detected in corn extruded with glucose was N‐(deoxy‐D‐fructos‐1‐yl)‐FB1, while 23% to 37% of FB1 species detected in extruded corn grits with and without added glucose was bound to the matrix. It was also found that the hydrolyzed form of FB1 was a minor species in extruded corn grits with or without added glucose, representing <15% of the total FB1 species present. Less than 46% of FB1 originally present in corn grits could be detected in the fumonisin analogues measured in this study. Research is needed to identify the reaction products resulting from extrusion processing of fumonisin‐contaminated corn products. Practical Application: Twin‐screw extrusion is widely used in food industry for its versatility. This technology may reduce the level of fumonisins in corn particularly with added glucose.  相似文献   
56.
57.
Reports an error in "The MMPI-2 Restructured Clinical Scales in the assessment of posttraumatic stress disorder and comorbid disorders" by Erika J. Wolf, Mark W. Miller, Robert J. Orazem, Mariann R. Weierich, Diane T. Castillo, Jaime Milford, Danny G. Kaloupek and Terence M. Keane (Psychological Assessment, 2008[Dec], Vol 20[4], 327-340). The URL for the supplemental material was incomplete. The complete URL is http://dx.doi.org/10.1037/a0012948.supp (The following abstract of the original article appeared in record 2008-17693-002.) This study examined the psychometric properties of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Restructured Clinical Scales (RCSs) in individuals with posttraumatic stress disorder (PTSD) receiving clinical services at Department of Veterans Affairs medical centers. Study 1 included 1,098 men who completed the MMPI-2 and were assessed for a range of psychological disorders via structured clinical interview. Study 2 included 136 women who completed the MMPI-2 and were interviewed with the Clinician Administered Scale for PTSD. The utility of the RCSs was compared with that of the Clinical Scales (CSs) and the Keane PTSD (PK) scale. The RCSs demonstrated good psychometric properties and patterns of associations with other measures of psychopathology that corresponded to current theory regarding the structure of comorbidity. A notable advantage of the RCSs compared with the MMPI-2 CSs was their enhanced construct validity and clinical utility in the assessment of comorbid internalizing and externalizing psychopathology. The PK scale demonstrated incremental validity in the prediction of PTSD beyond that of the RCSs or CSs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
58.
The flowers of Senecio vulgaris contain the alkaloids senecionine, seneciphylline, and their N-oxides, compounds which are toxic to some grazing animals. Deficiencies of water, mineral nutrients, or both did not significantly alter concentrations of the individual alkaloids. However, more favourable growing conditions resulted in a greater quantity of flowers, which animals find quite palatable, so that each of these plants was potentially more toxic because it contained a larger total amount of the alkaloids.  相似文献   
59.
Thermal conductivities of four types of granular rice starches, regular, low protein, waxy and low protein waxy, were measured at bulk densities of 600 and 800 kg/m3, temperatures of 20, 50 and 80 °C, and moisture contents of 4, 20 and 40% (wet basis), using a line‐source thermal probe system equipped with a computerized data acquisition system. A completely randomized experimental design with factorial treatment structure resulted in a total of 72 treatments, each with 3 replications. The thermal conductivity was significantly different among various rice starches. Low protein and waxy rice starches had higher thermal conductivities than regular and low protein waxy rice starches. Thermal conductivity increased significantly with increases in bulk density, temperature and moisture content. Prediction models were developed to calculate thermal conductivity values for practical applications.  相似文献   
60.
Properties of Chitosan Films as a Function of pH and Solvent Type   总被引:2,自引:0,他引:2  
ABSTRACT: Two different deacetylated chitosans were dissolved in formic, acetic, lactic, or propionic acid to prepare chitosan films. The pH values of the film-forming solutions were adjusted to 3, 4, and 5. Water vapor permeability (WVP), tensile strength (TS), elongation (E), and total soluble matter (TSM) were significantly ( P < 0.05) affected by acid type, pH, and degree of deacetylation (DA). Low DA (LDA) chitosan films had lower WVP and TSM, higher TS compared with high DA (HDA) chitosan films. The E values were not affected by DA. As pH increased, WVP and TSM of chitosan films tended to increase while TS decreased significantly ( P < 0.05). Chitosan films with acetic and propionic acid solvents had low WVP and TSM and high TS, while films with lactic acid solvent had high E and TSM and the lowest TS. Fourier-transform infrared showed peak shifting in the spectra with different solvents and at different pH values. Chitosan films with lactic acid solvent showed a peak shift to a lower frequency range. The NH3+ band was absent in the pH 5.0 chitosan film spectra.  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