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   3489835篇
  免费   247722篇
  国内免费   8798篇
耳鼻咽喉   47163篇
儿科学   115666篇
妇产科学   97904篇
基础医学   494946篇
口腔科学   97914篇
临床医学   320377篇
内科学   679474篇
皮肤病学   81825篇
神经病学   283414篇
特种医学   135490篇
外国民族医学   1044篇
外科学   514708篇
综合类   69870篇
现状与发展   7篇
一般理论   1450篇
预防医学   276869篇
眼科学   78762篇
药学   254503篇
  14篇
中国医学   6578篇
肿瘤学   188377篇
  2018年   39733篇
  2017年   31540篇
  2016年   34978篇
  2015年   40636篇
  2014年   54029篇
  2013年   79557篇
  2012年   109795篇
  2011年   112245篇
  2010年   66761篇
  2009年   65298篇
  2008年   103553篇
  2007年   110571篇
  2006年   111892篇
  2005年   114317篇
  2004年   111707篇
  2003年   104426篇
  2002年   97260篇
  2001年   157945篇
  2000年   160616篇
  1999年   137356篇
  1998年   39438篇
  1997年   35111篇
  1996年   35570篇
  1995年   34245篇
  1994年   31581篇
  1993年   29586篇
  1992年   109165篇
  1991年   106367篇
  1990年   103275篇
  1989年   99744篇
  1988年   92111篇
  1987年   90323篇
  1986年   85202篇
  1985年   80916篇
  1984年   60760篇
  1983年   51796篇
  1982年   30496篇
  1981年   27339篇
  1979年   55131篇
  1978年   39234篇
  1977年   33221篇
  1976年   30669篇
  1975年   33331篇
  1974年   39888篇
  1973年   38330篇
  1972年   36191篇
  1971年   33794篇
  1970年   31445篇
  1969年   30050篇
  1968年   27824篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
41.
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric plasma equilibrium problem. The proposed method, obtained from an improvement of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium problem in unbounded domains by discretizing only the plasma region; the external conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github. om/matteobonotto/ FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against experimental data from RFX-mod device, and numerical equilibria of an ITER-like device.  相似文献   
42.
Journal of Neuro-Oncology - Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45–54 Gy. We used the...  相似文献   
43.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
44.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  相似文献   
45.
46.
47.
Introduction: The Hedgehog (HH) pathway constitutes a collection of signaling molecules which critically influence embryogenesis. In adults, however, the HH pathway remains integral to the proliferation, maintenance, and apoptosis of adult stem cells including hematopoietic stem cells.

Areas covered: We discuss the current understanding of the HH pathway as it relates to normal hematopoiesis, the pathology of acute myeloid leukemia (AML), the rationale for and data from combination therapies including HH pathway inhibitors, and ultimately the prospects that might offer promise in targeting this pathway in AML.

Expert opinion: Efforts to target the HH pathway have been focused on impeding this disposition and restoring chemosensitivity to conventional myeloid neoplasm therapies. The year 2018 saw the first approval of a HH pathway inhibitor (glasdegib) for AML, though for an older population and in combination with an uncommonly-used therapy. Several other clinical trials with agents targeting modulators of HH signaling in AML and MDS are underway. Further study and understanding of the interplay between the numerous aspects of HH signaling and how it relates to the augmented survival of AML will provide a more reliable substrate for therapeutic strategies in patients with this poor-risk disease.  相似文献   

48.
49.
50.
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field.  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