全文获取类型
收费全文 | 354178篇 |
免费 | 23545篇 |
国内免费 | 7858篇 |
专业分类
耳鼻咽喉 | 4132篇 |
儿科学 | 9651篇 |
妇产科学 | 6672篇 |
基础医学 | 28235篇 |
口腔科学 | 8281篇 |
临床医学 | 38751篇 |
内科学 | 43371篇 |
皮肤病学 | 4674篇 |
神经病学 | 19865篇 |
特种医学 | 8153篇 |
外国民族医学 | 32篇 |
外科学 | 37199篇 |
综合类 | 54584篇 |
现状与发展 | 13篇 |
一般理论 | 33篇 |
预防医学 | 36449篇 |
眼科学 | 5505篇 |
药学 | 31786篇 |
438篇 | |
中国医学 | 34050篇 |
肿瘤学 | 13707篇 |
出版年
2023年 | 5517篇 |
2022年 | 8443篇 |
2021年 | 13785篇 |
2020年 | 12854篇 |
2019年 | 18686篇 |
2018年 | 16325篇 |
2017年 | 13314篇 |
2016年 | 10795篇 |
2015年 | 10046篇 |
2014年 | 20885篇 |
2013年 | 22230篇 |
2012年 | 19130篇 |
2011年 | 21138篇 |
2010年 | 17353篇 |
2009年 | 15373篇 |
2008年 | 14869篇 |
2007年 | 15425篇 |
2006年 | 13565篇 |
2005年 | 11690篇 |
2004年 | 9427篇 |
2003年 | 8309篇 |
2002年 | 6506篇 |
2001年 | 5798篇 |
2000年 | 4784篇 |
1999年 | 4147篇 |
1998年 | 3356篇 |
1997年 | 3201篇 |
1996年 | 2761篇 |
1995年 | 2657篇 |
1994年 | 2564篇 |
1993年 | 2030篇 |
1992年 | 2067篇 |
1991年 | 1779篇 |
1990年 | 1596篇 |
1989年 | 1411篇 |
1988年 | 1334篇 |
1987年 | 1146篇 |
1985年 | 3841篇 |
1984年 | 4857篇 |
1983年 | 3386篇 |
1982年 | 3870篇 |
1981年 | 3610篇 |
1980年 | 3213篇 |
1979年 | 2953篇 |
1978年 | 2583篇 |
1977年 | 1944篇 |
1976年 | 2188篇 |
1975年 | 1657篇 |
1974年 | 1450篇 |
1973年 | 1295篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
951.
医院综合效益评价案例分析 总被引:2,自引:0,他引:2
西南地区医院综合效益评价课题组 《中国医院管理》1994,14(2):32-35
运用层次分析法建立了医院综合效益评价指标体系,开发了医院综合效益九型评价图,用于显著评价结果。在此基础上进行了3个案例的评价分析。论述了通过对西南地区27所医院综合效益4年多的追踪分析所发现的共性问题,并提出了相应的管理对策。 相似文献
952.
953.
954.
955.
在连续361例患者心内电生理检查中,发现4例有心脏传导的裂隙现象。其特点表现为激动传导方向上远端平面相对不应期(RRP)长,程序刺激中先出现传导延缓,随后近端平面也进入RRP使传导变为延缓,激动经过近端平面延缓传导后,到达远端平面时其已脱离了RRP,使已经在远端传导延缓的情况变为传导正常,与经典的裂隙现象相比,这种裂隙现象的发生机制,与心内电图的表现均有不同,暂定名为变异性裂隙现象。 相似文献
956.
Christopher J. Holmgren Esmonde F. Corbet L. P. Lim 《Community dentistry and oral epidemiology》1994,22(5):396-402
Abstract The aim of this study was to describe the periodontal conditions in 372 35–44-yr-old and 537 noninstitutionalized 65–74-yr-old Hong Kong Chinese who were examined clinically for loss of attachment, recession, probing depth, calculus, and bleeding after probing. Community Periodontal Index (CPI) data and treatment need indications were compiled from index teeth or their substitutes. The prevalence of loss of attachment varied considerably in both cohorts according to the definition of the threshold (≥6, ≥9, and ≥12 mm, respectively). The mean numbers of teeth with loss of attachment at the ≥6-mm threshold and at higher thresholds were small. In both age cohorts, about one-fifth of subjects had probing depths ≥6-mm, while al the ≥9-mm threshold only 2–3% were so affected. Although recession was an important component of loss of attachment in the younger cohort, in the older cohort the prevalence and extent of recession were greater than for probing depths at thresholds ≥4 mm. All subjects had one or more teeth with calculus, bleeding, or both, most teeth being so affected. Eighty-four of the 537 65–74-yr-old subjects were excluded either because of edentulousness or because extractions indicated for the remaining teeth would have rendered the subjects edentulous. The distribution of subjects according to their highest CPI score was remarkably similar for the two cohorts. No subjects in either age group were assessed as “healthy” (CPI code 0) or had “bleeding only” (code 1) as their highest score. While most subjects scored CPI code 2 or 3 us their highest score, only 17% of the younger and 15% of the older cohort scored Community Periodontal Index of Treatment Needs (CPITN) code 4. Differences in the mean number of sextants affected by CPI codes between the two cohorts were mainly due to a greater number of excluded sextants in the older cohort. CPI findings for 35–44-yr-olds differed little from those reported in 1984. 相似文献
957.
根据热分析谱图峰顶的数学特征与Coats-Redfern方程,推得在一定实验条件下,在系列相关反应中,若峰顶温度相接近,则各反应的表观活化能E与指前因子A之间存在着有动力学意义的补偿效应,即lnA=aE+b。并经系列含水硫酸盐脱水反应实验验证。 相似文献
958.
L Peichl 《The Journal of comparative neurology》1992,324(4):590-602
The morphological types of ganglion cells in the dog and wolf retina were studied by intracellular staining with Lucifer Yellow. These retinae contain a range of ganglion cell types that closely correspond to those found in cat retina: alpha cells with large somata and large, relatively densely branched dendritic trees; beta cells with medium-sized somata and small, densely branched dendritic trees; and a variety of other types with smaller somata and varying dendritic branching patterns and dendritic field sizes. The correspondence of canine and cat ganglion cell types strengthens the view that there is a common set of ganglion cell types in carnivores. Alpha and beta cell dendritic trees of dog and wolf are monostratified in either the inner or the outer part of the inner plexiform layer, suggesting an on/off dichotomy in the response to light. Dendritic field sizes of dog alpha and beta cells increase from the central area to peripheral retina: alpha cell fields from 160-200 microns to about 1,100 microns diameter, and beta cell fields from 25 microns to about 360 microns diameter. These sizes are quantitatively very similar to those found in cat retina. The close qualitative and quantitative morphological correspondence of cat and dog ganglion cells suggests that they are also functionally very similar. It is likely that dog alpha cells have brisk-transient (Y), and dog beta cells brisk-sustained (X) concentric receptive fields. From the smallest beta cell sizes it is concluded that the visual acuity of the dog may be as good as that of the cat. 相似文献
959.
960.