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   30698篇
  免费   2529篇
  国内免费   107篇
耳鼻咽喉   412篇
儿科学   859篇
妇产科学   538篇
基础医学   3952篇
口腔科学   742篇
临床医学   3127篇
内科学   6138篇
皮肤病学   322篇
神经病学   3094篇
特种医学   1358篇
外科学   4504篇
综合类   583篇
一般理论   20篇
预防医学   3072篇
眼科学   1011篇
药学   1962篇
中国医学   43篇
肿瘤学   1597篇
  2021年   305篇
  2020年   231篇
  2019年   328篇
  2018年   367篇
  2017年   297篇
  2016年   341篇
  2015年   470篇
  2014年   728篇
  2013年   1266篇
  2012年   1629篇
  2011年   1865篇
  2010年   1025篇
  2009年   979篇
  2008年   1731篇
  2007年   1965篇
  2006年   1989篇
  2005年   2024篇
  2004年   1902篇
  2003年   1891篇
  2002年   1950篇
  2001年   291篇
  2000年   218篇
  1999年   353篇
  1998年   447篇
  1997年   369篇
  1996年   353篇
  1995年   326篇
  1994年   317篇
  1993年   301篇
  1992年   250篇
  1991年   223篇
  1990年   200篇
  1989年   221篇
  1988年   224篇
  1987年   220篇
  1986年   219篇
  1985年   247篇
  1984年   323篇
  1983年   317篇
  1982年   455篇
  1981年   424篇
  1980年   423篇
  1979年   238篇
  1978年   242篇
  1977年   260篇
  1976年   192篇
  1975年   197篇
  1974年   210篇
  1973年   204篇
  1972年   179篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The prevention of the spread of disease by drinking water relies on a tripartate arrangement among the supplier, the regulator and their medical advisers. This paper describes the role of Public Health Medicine in Scotland in preventing a ‘significant risk to health’ from potable water. The legislative framework is highlighted. The rationale of water monitoring is examined and the role of Consultant in Public Health Medicine. The concept of Significant Medical Risk Values is introduced and their derivation, uses, and levels presented.  相似文献   
82.
83.
This study provides an overview of the papers emanating from the experimental trial that evaluated a new cognitive rehabilitation program in older adults who were experiencing normal cognitive decline. The main features of the design are summarized, along with evidence that the training produced long-lasting improvement in memory performance, goal management, and psychosocial status. The benefits were attributed to several factors, including the program's emphasis on techniques that promoted efficient strategic processing. Limitations of the program and directions for future research are discussed.  相似文献   
84.
In the last decade, recurrent neural networks (RNNs) have attracted more efforts in inferring genetic regulatory networks (GRNs), using time series gene expression data from microarray experiments. This is critically important for revealing fundamental cellular processes, investigating gene functions, and understanding their relations. However, RNNs are well known for training difficulty. Traditional gradient descent-based methods are easily stuck in local minima and the computation of the derivatives is also not always possible. Here, the performance of three evolutionary-swarm computation technology-based methods, known as differential evolution (DE), particle swarm optimization (PSO), and the hybrid of DE and PSO (DEPSO), in training RNNs is investigated. Furthermore, the gene networks are reconstructed via the identification of the gene interactions, which are explained through corresponding connection weight matrices. The experimental results on two data sets studied in this paper demonstrate that the DEPSO algorithm performs better in RNN training. Also, the RNN-based model can provide meaningful insight in capturing the nonlinear dynamics of genetic networks and revealing genetic regulatory interactions.  相似文献   
85.
The purpose of this paper is to detail the contraindications for surgery, with curative intent for those patients who suffer from a head and neck malignancy that invades the intracranial space. This is based on a 30-year experience of over 250 patients. The most important contraindications are anatomical. Surgery is not done if the following structures are invaded: brain stem, eloquent portions of the cerebrum, superior sagittal sinus, both internal carotid arteries, both cavernous sinuses and certain vital bridging veins. Certain tumor factors are absolute but are occasionally relative contraindications: such as distant metastatic disease especially if multiple and at multiple anatomic sites. Some tumors that behave in a particularly virulent fashion that defy complete resection but are often difficult to predict preoperatively. Lack of patient medical fitness or absence of patient commitment to the operative procedure is make-up two serious contraindications to surgery. Presented at the 77th Annual Meeting of the German Society for Oto-Rhino-Laryngology, Head and Neck Surgery, 24–28 May 2006, Mannheim, Germany.  相似文献   
86.
87.
We present three patients with Treacher Collins or Pierre Robin syndromes who had historical and physical evidence of airway obstruction, difficulty feeding, and sleep disturbances. These preoperative findings correlated with difficult airway management intraoperatively. Based on this experience, we recommend that children with obstructive symptoms have laryngoscopy prior to anaesthetic induction. If the glottic opening is visualized, inhalational induction can proceed. If the glottic structures cannot be visualized, then the anaesthetist must choose between awake oral or nasal intubation, elective tracheostomy, or fiberoptic intubation. In all cases, a tracheostomy tray should be ready and a surgeon experienced in paediatric tracheostomy should be in attendance. After intubation, anaesthesia is best maintained with oxygen and a potent inhalational agent. Extubation should only be done with the patient fully awake and with emergency airway equipment immediately available. Postoperatively, these patients should be transferred to an intermediate care area or intensive care unit where they can be observed closely since delayed complications of airway obstruction are common in this group of patients.  相似文献   
88.
The authors review the relationship that has evolved over the years between the Department of Psychiatry at Oregon Health Sciences University and Oregon's community and state mental health programs. They describe the compatibility that exists between the basic requirements of academic psychiatry departments and public mental health programs and demonstrate how these organizations have been able to fulfill one another's needs in Oregon. Specific examples of successful collaborations in the areas of education, administration, research, and service are presented to illustrate how relationships that have been designed to meet specific requirements of one organization can fulfill many requirements of both. Suggestions are provided for those organizations contemplating similar collaborative endeavors.  相似文献   
89.
90.
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