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   1095篇
  免费   0篇
化学工业   3篇
能源动力   2篇
轻工业   2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   4篇
冶金工业   1080篇
自动化技术   1篇
  2020年   1篇
  2011年   1篇
  2010年   2篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2002年   1篇
  2000年   1篇
  1999年   22篇
  1998年   295篇
  1997年   170篇
  1996年   112篇
  1995年   55篇
  1994年   57篇
  1993年   59篇
  1992年   15篇
  1991年   15篇
  1990年   8篇
  1989年   21篇
  1988年   22篇
  1987年   21篇
  1986年   20篇
  1985年   25篇
  1983年   1篇
  1982年   5篇
  1981年   6篇
  1980年   17篇
  1978年   5篇
  1977年   40篇
  1976年   90篇
  1975年   2篇
  1968年   1篇
  1955年   1篇
  1954年   1篇
排序方式: 共有1095条查询结果,搜索用时 240 毫秒
71.
72.
Alcohol consumption by young actively growing rats has been previously demonstrated to decrease cortical and cancellous bone density, to reduce trabecular bone volume, and to inhibit bone growth at the epiphyseal growth plate. This study addresses the action of alcohol on cortical bone growth using histomorphometric techniques and on mechanical properties by three-point bending. Four-week-old, female Sprague-Dawley rats were divided into three groups. Alcohol-treated animals were fed a modified Lieber-DeCarli diet ad libitum containing 35% ethanol-derived calories, whereas the pair-fed animals (weight-matched to ethanol rats) received an isocaloric liquid diet in which maltose-dextrin-substituted calories were supplied by ethanol. Chow animals were fed a standard rat chow ad libitum. Femora were removed for analysis after 2, 4, 6, or 8 weeks on the diets. Cortical bone area, bone formation rates, and mineral apposition rates were reduced in the alcohol-fed animals. Bone stiffness, strength, and energy absorbed to fracture were significantly lower in the alcohol-fed animals. This distinctive alcohol effect was revealed to be caused by lower quality bone tissue as reflected by lower elastic moduli and yield strengths.  相似文献   
73.
74.
75.
76.
77.
78.
The effect of electrode density for lithium intercalation and irreversible capacity loss on the natural graphite anode in lithium ion batteries was studied by electrochemical methods. Both the first-cycle reversible and irreversible capacities of the natural graphite anode decreased with an increase in the anode density though compression. The reduction in reversible capacity was attributed to a reduction in the chemical diffusion coefficient for lithium through partially agglomerated particles with a larger stress. For the natural graphite in this study the potentials for Li (de)insertion shifted between the first and second formation cycles and the extent of this shift was dependent on electrode density. The relation between this peak shift and the irreversible capacity loss is probably due to the decrease in graphite surface area with compression.  相似文献   
79.
80.
Disturbed eating behaviour and disturbed body experience are important features for the differential diagnosis of eating disorders from other disorders. Eating disorders occur mainly in young females. The one-year prevalence of anorexia nervosa is 0.4% and that of bulimia nervosa 1.5% among young females. To motivate patients for treatment it is important to discuss physical problems and the high risk of severe complications with them. It is difficult to motivate patients for treatment, because anorexia nervosa patients deny their illness and bulimia nervosa patients are ashamed and hide their disturbed eating behaviour. The treatment of anorexia nervosa consists of two partly overlapping phases: normalizing the eating pattern to improve weight restoration and psychotherapeutic treatment for underlying emotional problems. Family therapy is effective for patients younger than 18 years with a short duration of illness. Cognitive behaviour therapy is the most important form of treatment for bulimia nervosa.  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