全文获取类型
收费全文 | 45677篇 |
免费 | 4245篇 |
国内免费 | 1116篇 |
专业分类
耳鼻咽喉 | 882篇 |
儿科学 | 636篇 |
妇产科学 | 1424篇 |
基础医学 | 3184篇 |
口腔科学 | 1606篇 |
临床医学 | 9566篇 |
内科学 | 5382篇 |
皮肤病学 | 413篇 |
神经病学 | 1678篇 |
特种医学 | 4071篇 |
外国民族医学 | 10篇 |
外科学 | 9175篇 |
综合类 | 6373篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 1578篇 |
眼科学 | 725篇 |
药学 | 1632篇 |
66篇 | |
中国医学 | 372篇 |
肿瘤学 | 2261篇 |
出版年
2024年 | 122篇 |
2023年 | 914篇 |
2022年 | 1605篇 |
2021年 | 2123篇 |
2020年 | 2439篇 |
2019年 | 2093篇 |
2018年 | 2027篇 |
2017年 | 1979篇 |
2016年 | 1931篇 |
2015年 | 1932篇 |
2014年 | 3484篇 |
2013年 | 3278篇 |
2012年 | 2572篇 |
2011年 | 2885篇 |
2010年 | 2229篇 |
2009年 | 2136篇 |
2008年 | 2221篇 |
2007年 | 2251篇 |
2006年 | 1960篇 |
2005年 | 1608篇 |
2004年 | 1390篇 |
2003年 | 1201篇 |
2002年 | 892篇 |
2001年 | 793篇 |
2000年 | 631篇 |
1999年 | 596篇 |
1998年 | 510篇 |
1997年 | 498篇 |
1996年 | 402篇 |
1995年 | 341篇 |
1994年 | 332篇 |
1993年 | 244篇 |
1992年 | 201篇 |
1991年 | 166篇 |
1990年 | 139篇 |
1989年 | 114篇 |
1988年 | 110篇 |
1987年 | 77篇 |
1986年 | 90篇 |
1985年 | 113篇 |
1984年 | 98篇 |
1983年 | 42篇 |
1982年 | 68篇 |
1981年 | 56篇 |
1980年 | 48篇 |
1979年 | 34篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 16篇 |
1975年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Guoliang Zhang & Tao Xiong 《Communications In Computational Physics》2022,32(1):126-155
We propose a high order finite difference linear scheme combined with a
high order bound preserving maximum-principle-preserving (MPP) flux limiter to
solve the incompressible flow system. For such problem with highly oscillatory structure but not strong shocks, our approach seems to be less dissipative and much less
costly than a WENO type scheme, and has high resolution due to a Hermite reconstruction. Spurious numerical oscillations can be controlled by the weak MPP flux
limiter. Numerical tests are performed for the Vlasov-Poisson system, the 2D guiding-center model and the incompressible Euler system. The comparison between the linear
and WENO type schemes, with and without the MPP flux limiter, will demonstrate the
good performance of our proposed approach. 相似文献
3.
Guo-Quan Shi Huajun Zhu & Zhen-Guo Yan 《Communications In Computational Physics》2022,31(4):1215-1241
A priori subcell limiting approach is developed for high-order flux reconstruction/correction procedure via reconstruction (FR/CPR) methods on two-dimensional unstructured quadrilateral meshes. Firstly, a modified indicator based on
modal energy coefficients is proposed to detect troubled cells, where discontinuities
exist. Then, troubled cells are decomposed into nonuniform subcells and each subcell has one solution point. A second-order finite difference shock-capturing scheme
based on nonuniform nonlinear weighted (NNW) interpolation is constructed to perform the calculation on troubled cells while smooth cells are calculated by the CPR
method. Numerical investigations show that the proposed subcell limiting strategy on
unstructured quadrilateral meshes is robust in shock-capturing. 相似文献
4.
5.
目的探讨多元化联合教学模式在超声引导下疼痛介入治疗教学中的应用效果。方法选择2018年1月至2020年12月在北京大学第三医院疼痛科进修的30名医师作为研究对象,将其分为对照组与观察组;对照组采用常规教学模式;观察组采用多元化联合教学模式,比较两组医师技能考核成绩、教学质量评分和满意度评分。结果观察组医师技能考核成绩优良率为93.3%,高于对照组的73.3%(P<0.05);观察组医师对基础理论知识掌握、临床思维能力的提高、学习兴趣的激发、疾病诊治能力的提高4个方面的评分均高于对照组(P<0.01)。结论多元化联合教学模式可促进超声引导下疼痛介入治疗技能的提高,有利于提高学员的综合临床能力。 相似文献
6.
7.
8.
9.
郭永华 《临床超声医学杂志》2019,21(2)
目的:总结后颅窝正常和异常的胎儿小脑及小脑蚓部的矢状面的声像学特征,了解小脑细微结构的改变与胎儿畸形的关系。 相似文献
10.
Aaron Pitzele Mohammad Rahimi Eric Armbrecht 《The journal of maternal-fetal & neonatal medicine》2015,28(15):1770-1773
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion. 相似文献