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   4397篇
  免费   131篇
  国内免费   2篇
  2021年   34篇
  2020年   46篇
  2019年   55篇
  2018年   76篇
  2017年   97篇
  2016年   111篇
  2015年   74篇
  2014年   76篇
  2013年   512篇
  2012年   163篇
  2011年   159篇
  2010年   101篇
  2009年   110篇
  2008年   129篇
  2007年   144篇
  2006年   130篇
  2005年   147篇
  2004年   131篇
  2003年   129篇
  2002年   138篇
  2001年   60篇
  2000年   54篇
  1999年   70篇
  1998年   88篇
  1997年   65篇
  1996年   67篇
  1995年   60篇
  1994年   59篇
  1993年   54篇
  1992年   51篇
  1991年   54篇
  1990年   48篇
  1989年   63篇
  1988年   54篇
  1987年   45篇
  1986年   44篇
  1985年   45篇
  1984年   61篇
  1983年   54篇
  1982年   67篇
  1981年   51篇
  1980年   55篇
  1979年   57篇
  1978年   60篇
  1977年   49篇
  1976年   51篇
  1975年   43篇
  1974年   51篇
  1973年   52篇
  1969年   35篇
排序方式: 共有4530条查询结果,搜索用时 15 毫秒
241.
The influence of a genetic risk factor, apolipoprotein E (apoE) epsilon4 variant, was assessed in older adults aged 70 to 94 on 3 occasions over 7 years. The results of latent growth curve analyses are reported for individuals genotyped for apoE at the 2nd measurement occasion (n = 601) and for a subsample of individuals without probable or definite dementia during the 1st or 2nd occasion (n = 434). ApoE-epsilon4 status was a significant predictor of level and change in memory performance and change in speed performance in the full sample, and of initial level and change in memory performance in the nondemented subsample. These results support previous findings that apoE-epsilon4 is associated with accelerated memory deterioration in individuals without clinical dementia.  相似文献   
242.
An archival study was performed in a maximum security forensic hospital to evaluate the effects of a total ban on smoking and all tobacco products. One hundred and forty patients were characterized as nonsmokers or light, moderate or heavy smokers. Patient records for the four weeks prior to the ban were compared with their records for the four weeks subsequent to the ban. Numbers of sick calls, total disruptive behaviors and verbal aggression declined markedly and significantly following the ban in those patients previously classified as moderate or heavy smokers. Weight increased significantly, but almost equally regardless of previous smoking status. Patients, and eventually staff, tolerated the smoking ban without significant negative effects. Patients relied very little on treatment modalities to alleviate nicotine withdrawal. Pre-ban apprehension by staff and patients dissipated with time after the smoking ban started.  相似文献   
243.
The psychology of thought and memory has historically been concerned with a struggle between associationism and its opponents. Organisation theory--in part an offspring of Gestalt concepts--has been the most successful and vocal of these contenders. The levels-of-processing framework has been a part of the effort to overcome associationist predilections. Aspects of principles of organisation and of the recent history of organisation theory are presented, followed by an analysis of the levels-of-processing approach in terms of organisational concepts.  相似文献   
244.
Pessimism     
The problem of pessimism is the secular analogue to the evidential problem of evil facing traditional theism. The traditional theist must argue two things: that the evidence shows that this is on balance a good world and that it is the best possible world. Though the secular optimist who advocates any form of secular moral theory need not argue that the current and future world will likely be the best possible world, she nonetheless must argue that were there a clean solution to the problem of current and future suffering in which all sentient life could be instantly and painlessly eliminated, we would have reasons not to employ the clean solution because the future promises to bring on balance a good world in which the evil of human and animal suffering is outweighed by whatever is good in the world. Pessimism is the view that the evidence argues against secular optimism. It is argued here that it is anything but clear that secular optimism is warranted when viewed from an impersonal point of view. The problem is then evaluated from the personal point of view in which a form of personal optimism is defended even in the face of impersonal pessimism.  相似文献   
245.
Volume Contents     

Volume Contents

Volume Contents  相似文献   
246.
Although the vagus nerve has traditionally been considered to perform efferent functions, in reality it performs significant afferent functions as well, carrying information from the body, head, and neck to the brain. Preliminary studies examining this afferent activity led to the theory that vagus nerve stimulation (VNS) could successfully control seizure activity in persons who are refractory to antiepileptic medications. Unlike other forms of brain stimulation, VNS is unable to directly stimulate multiple discrete areas of the brain; however, through several pathways, it is able to relay sensory information to higher brain regions. An implantable VNS device known as the VNSTM NeuroCybernetic Prosthesis (NCP) System has been used in approximately 9,000 epilepsy patients in Europe and the United States since 1994. The implant has reduced seizure frequency by an average of 25% to 30%, with minimal side effects. Studies underway are also showing some degree of success in the management of treatment-refractory depression. The future efficacy of the implantable system in other disorders may depend on whether the implant can be more precisely focused to affect different brain regions. Research in this area is underway.  相似文献   
247.
Conclusion Wise counseling can relieve the anxiety and inner conflict of parents torn between the dread of their retarded offspring becoming a parent and the fear of an operation they believe to be illegal, immoral, and castrating.By knowing where to refer patients, clergymen can make it possible for some of these deprived members of society to find support and love within marriage without being overburdened by children they are not capable of rearing properly.  相似文献   
248.
249.
250.
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