首页 | 官方网站   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   113篇
  免费   7篇
工业技术   120篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   4篇
  2017年   3篇
  2016年   3篇
  2015年   5篇
  2014年   3篇
  2013年   9篇
  2012年   7篇
  2011年   9篇
  2010年   6篇
  2009年   5篇
  2008年   7篇
  2007年   3篇
  2006年   6篇
  2005年   2篇
  2004年   1篇
  2003年   9篇
  2002年   7篇
  2001年   2篇
  2000年   3篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1993年   1篇
  1992年   2篇
  1990年   2篇
  1989年   1篇
  1986年   1篇
  1985年   2篇
  1982年   1篇
  1977年   1篇
  1973年   1篇
排序方式: 共有120条查询结果,搜索用时 578 毫秒
71.
72.
The digestibility of starch in homogenized/autoclaved pea plus potato products was studied in vitro and in vivo. The products were a canned infant purée based on peas and potatoes and products prepared in the laboratory by repeated autoclaving and cooling of either homogenized potatoes or homogenized peas. Small-intestinal digestibility was evaluated through balance experiments in rats treated with an antibiotic (Nebacitin) to supress microbial activity in the hind gut. Parallel experiments in normal rats were performed to study the fermentability of undigested starch. The small-intestinal digestibility was 93, 82 and 70% of tolal starch in the potato product, infant purée and pea product, respectively. Consequently, significant amounts of starch left the small intestine undigested, particularly with pea-based products. The major portion of the undigested starch consisted of a fraction which resisted amylases in vitro unless solubilized in alkali, ie retrograded amylose. The fermentability of starch reaching the hind gut was high, about 90%. In-vitro digestibility figures varied depending on the method used and were in the ranges 91–93, 76–86 and 71–77% in the potato product, infant purée and pea product, respectively. One of the methods allowed simultaneous and accurate determination of the in-vivo resistant retrograded amylose fraction.  相似文献   
73.
Polymeric microgels were prepared from dextran (Dex) by crosslinking linear natural polymer dextran with divinyl sulfone (DVS) with a surfactant-free emulsion technique resulting in high gravimetric yield of 78.5 ± 5.3% with wide size distribution. Dex microgels were chemically modified, and then used as catalyst in the methanolysis of NaBH4 to produce H2. The chemical modification of Dex microgel was done on epichlorohydrin (ECH)-reacted Dex microgels with ethylenediamine (EDA), diethylenetriamine (DETA), and triethylenetetraamine (TETA) in dimethylformamide (DMF) at 90°C for 12 hours. The modified dextran-TETA microgels were protonated using treatment with hydrochloric acid (HCl) and m-Dex microgels-TETA-HCl was found to be a very efficient catalyst for methanolysis of NaBH4 to produce H2. The effects of reaction temperature and NaBH4 concentration on H2 generation rates were investigated and m-Dex microgels-TETA-HCl catalyst possessed excellent catalytic performances with 100% conversion and 80% activity at end of 10 consecutive uses and was highly re-generatable with simple HCl treatment. Interestingly, m-Dex microgels-TETA-HCl catalyst can catalyze NaBH4 methanolysis reaction in a mild temperature range 0 to 35°C with Ea value of 30.72 kJ/mol and in subzero temperature range, −20 to 0°C with Ea value of 32.87 kJ/mol, which is comparable with many catalysts reported in the literature.  相似文献   
74.
75.
The aim of this study was to use 13C-nuclear magnetic resonance (NMR) regiospecific analyses of triacylglycerols to distinguish fish oils from different fish species for authentication purposes. 13C-NMR data of muscle lipids from Atlantic salmon (Salmo salar L.), mackerel (Scomber scombrus) and herring (Clupea harengus) were obtained, and the distribution of omega-3 polyunsaturated fatty acids between the sn-1,3 and sn-2 glycerol chains calculated from the carbonyl region. The results show that there were significant differences in the sn-2 position specificity of the fatty acids 22:6n-3, 20:5n-3 and 18:4n-3 among the species investigated. The most pronounced difference was that herring had a higher proportion of its 22:6n-3 in the sn-2 position compared to the two other species. Principal component analysis of data points in the carbonyl-region showed that there were also differences in the level and regiospecific distribution of monounsaturated/saturated fatty acids, which made it possible to distinguish oils of these three species solely from the carbonyl region of 13C-NMR spectra.  相似文献   
76.
77.
ABSTRACT. Objective: To evaluate the reliability and validity of the Accident Fear Questionnaire (AFQ; K. Kuch, B. J. Cox, & D. M. Direnfeld, 1995), a self-rated instrument developed for efficient screening of posttraumatic stress disorder (PTSD) and phobic avoidance after involvement in a motor vehicle accident (MVA). Participants: One hundred thirteen individuals receiving rehabilitation after an MVA. Setting: Tertiary rehabilitation center. Main Measures: The AFQ, comprising a 10-item accident profile and a 10-item phobic avoidance (PA) subscale; a structured clinical interview; and other self-report measures of psychopathology, personality and pain. Results: Correlations between the AFQ-PA total score and measures of psychopathology and personality indicated adequate convergent and discriminant validity. Patients diagnosed with PTSD or accident phobia scored higher on the AFQ-PA subscale and 6 of its 10 items than did those with neither diagnosis. An AFQ-PA cutoff score of 15 appears suitable for screening of patients in a rehabilitation setting. Hierarchical logistic regression indicated that the AFQ-PA was the only self-report measure that possessed incremental power over and above general negative affectivity in predicting group membership… (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
78.
The aim of this study was to examine Peruvian anchovy oil fatty acid (FA) compositions, and to test the possibility of using the FA data to classify the oils according to geographical origin along the Peruvian coast. The levels of contaminants in a representative set of samples were determined to examine the general levels and investigate if such measurements could aid in future discrimination between oils. The FA results showed that the two known stocks of Peruvian anchovy displayed different levels of docosahexaenoic acid (DHA, 22:6n-3) (southern stock; 14.4 ± 0.8% versus central-northern stock; 9.9 ± 1.2%). However, principal component analysis (PCA) of the FA data indicated clusters according to three regions; North, Center and South. Using a data set of 57 anchovy samples and 21 FA as input, a probabilistic neural network (PNN) was constructed. For the validation data sets, “North” oils was predicted accurately 100% of the time, “Center” oils 100% and “South” oils 83% of the time. The levels of contaminants in the oils determined were low in all but one sample.  相似文献   
79.
Driving with alcohol and other psychoactive substances imposes an increased risk of severe injury accidents. In a population-based case–control design, the relative risks of severe driver injury (MAIS ≥ 2) by driving with ten substance groups were approximated by odds ratios (alcohol, amphetamines, benzoylecgonine, cocaine, cannabis, illicit opiates, benzodiazepines and Z-drugs, i.e. zolpidem and zopiclone, medicinal opioids, alcohol–drug combinations and drug–drug combinations). Data from six countries were included in the study: Belgium, Denmark, Finland, Italy, Lithuania and the Netherlands. Case samples (N = 2490) were collected from severely injured drivers of passenger cars or vans in selected hospitals in various regions of the countries. Control samples (N = 15,832) were sampled in a uniform sampling scheme stratified according to country, time, road type and season. Relative risks were approximated by odds ratios and calculated by logistic regression. The estimates were adjusted for age, gender and country.  相似文献   
80.
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-23

京公网安备 11010802026262号