全文获取类型
收费全文 | 53881篇 |
免费 | 5263篇 |
国内免费 | 3947篇 |
专业分类
耳鼻咽喉 | 405篇 |
儿科学 | 979篇 |
妇产科学 | 673篇 |
基础医学 | 5653篇 |
口腔科学 | 941篇 |
临床医学 | 7833篇 |
内科学 | 7410篇 |
皮肤病学 | 569篇 |
神经病学 | 2751篇 |
特种医学 | 1817篇 |
外国民族医学 | 21篇 |
外科学 | 4492篇 |
综合类 | 10041篇 |
现状与发展 | 14篇 |
一般理论 | 8篇 |
预防医学 | 4462篇 |
眼科学 | 1309篇 |
药学 | 6266篇 |
54篇 | |
中国医学 | 3351篇 |
肿瘤学 | 4042篇 |
出版年
2024年 | 174篇 |
2023年 | 781篇 |
2022年 | 1934篇 |
2021年 | 2472篇 |
2020年 | 1998篇 |
2019年 | 1730篇 |
2018年 | 1719篇 |
2017年 | 1748篇 |
2016年 | 1546篇 |
2015年 | 2396篇 |
2014年 | 3207篇 |
2013年 | 2910篇 |
2012年 | 4264篇 |
2011年 | 4520篇 |
2010年 | 3212篇 |
2009年 | 2629篇 |
2008年 | 3212篇 |
2007年 | 3178篇 |
2006年 | 3019篇 |
2005年 | 2828篇 |
2004年 | 2063篇 |
2003年 | 2019篇 |
2002年 | 1605篇 |
2001年 | 1332篇 |
2000年 | 1214篇 |
1999年 | 1093篇 |
1998年 | 673篇 |
1997年 | 624篇 |
1996年 | 481篇 |
1995年 | 438篇 |
1994年 | 393篇 |
1993年 | 240篇 |
1992年 | 277篇 |
1991年 | 216篇 |
1990年 | 174篇 |
1989年 | 141篇 |
1988年 | 129篇 |
1987年 | 106篇 |
1986年 | 98篇 |
1985年 | 75篇 |
1984年 | 46篇 |
1983年 | 34篇 |
1982年 | 19篇 |
1981年 | 24篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1975年 | 10篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
目的 探讨5km重复低压缺氧对小鼠肝脏及脾脏中微量元素的影响。方法 将小白鼠分为5km重复低压缺氧实验组及地面对照组。实验组每天进行5km重复低压缺氧30min,连续7d后,处死小鼠,取肝脏、脾脏烘干至恒重,采用火焰原子吸收法测定锌、铜、铁。结果 5km重复低压缺氧小鼠肝脏中Cu、Fe含量与对照组比较有显差异(P<0.05);脾脏中微量元素Fe的含量与对照组比较有显性差异(P<0.05)。结论 5km重复低压缺氧,使肝脏中Fe、Cu含量降低,脾脏中Fe含量升高。 相似文献
22.
23.
本文采用RP-HPLC方法对紫苏油及其习用品白苏油、野苏油甘油酯进行了定性定量分析。利用HPLC分析油脂也为中药材真伪鉴别提供了一条有效途径。 相似文献
24.
Objective:To explore the effect of thrombolysis with anticoagulation treatment forearly stage of deep vein thrombosis of lower extremity.Methods:The clinical data of 10 patients at the early stage of deep vein thrombosis(DVT)in the lower extremuites treated by thrombolysis with anticoagulation and dispersion drugs were analyzed retrospectively.Results:The thrombolytic effect was significant.After treatment,the deep veins were recanalized without regurgitation in 75.3% of the patients.The total effective rate was 100%.Only three patients had hemorrhagic complication,but none of the patients died.Conclusion:Thrombolysis with anticoagulation treatment is an effective and safe method for DVT at the early stage. 相似文献
25.
人大肠癌不同转移潜能细胞株SW620及SW480的差异蛋白质组分析 总被引:2,自引:0,他引:2
26.
Genetic susceptibility of esophageal cancer in Linxian County 总被引:3,自引:0,他引:3
27.
Leonora Q. Schwandt Henri-Jacques Tjong-Ayong Ranny van Weissenbruch Henny C. der Mei Frans W. J. Albers 《European archives of oto-rhino-laryngology》2006,263(6):518-523
Tracheoesophageal voice prostheses need to be replaced due to increased airflow resistance or retrograde leakage of fluid into the trachea as a consequence of biofilm formation. Previous in vitro studies show a change of aerodynamic features of biofilm covered voice prostheses after removal of the prostheses out of the patient. To assess these changes in an in situ situation, aerodynamic characteristics were measured within 45 patients at the beginning and at the end of the wearing process of the Provox 2 voice prosthesis. As a consequence, the influence of biofilm formation on aerodynamic characteristics can be evaluated. In the majority of cases, leakage through the prosthesis was the reason for replacement. No differences were found in the total flow, volume range and intratracheal pressure (ITP) of the voice prostheses measured. The airflow resistance of biofilm covered prostheses was significantly reduced compared to new clean prostheses. However, no correlation was found between the extent of biofilm and the different aerodynamic features measured. Biofilm formation on the Provox 2 is responsible for both reduction in airflow resistance and leakage through the prosthesis by deterioration of the silicone rubber material. 相似文献
28.
目的 总结32例前列腺癌患者新辅助治疗(NHT)的作用。方法 32例前列腺癌患者中药物去势17例,手术去势15例,并联合抗雄激素治疗3个月,统计NHT前后前列腺癌体积、肿瘤大小、PSA、FSH、LH和睾酮水平变化。结果 2组NHT后前列腺体积明显变小、肿瘤变小、变软,甚至消失,PSA和睾酮明显下降,药物去势组睾酮水平在耻骨后前列腺癌根治术(RRP)术后2~3个月可恢复正常,而手术去势组RRP术后睾酮呈持续低水平。结论 NHT可明显缩小前列腺体积,降低PSA,有利于手术操作。药物去势对内分泌影响是可逆的,而手术去势内分泌改变不可逆。 相似文献
29.
相对于普通高校,高职高专学校中学业不良学生的比例更高,管理的难度更大。因此,分析、研究学生学业不良的成因,并采取科学有效的措施予以矫正,对于促进学生健康成长,全面提高教育教学质量,具有积极的意义。 相似文献
30.
Using rare earth element tracers and neutron activation analysis to study rill erosion process. 总被引:1,自引:0,他引:1
Mian Li Zhan-bin Li Weng-feng Ding Pu-ling Liu Wen-yi Yao 《Applied radiation and isotopes》2006,64(3):402-408
Spatially averaged soil erosion data provide little information on the process of rill erosion. The dynamically varied data on the temporal and spatial distributions in the rill erosion process are needed to better understand the erosion process and reveal its innate characteristics. The objectives of this study were to examine the feasibility and effectiveness of rare earth element (REE) tracers and the neutron activation analysis (NAA) method on the study of the rill erosion process and to reveal quantitatively the relationships and characteristics of temporal and spatial distributions of sediment yield in rill erosion. Four REEs were used to study the changeable process of rill erosion at 4 slope positions. Four water inflow rates were applied to a 0.3 x 5 m soil bed at 3 slopes of 10.5%, 15.8% and 21.2% in scouring experiments. All of the runoff was collected in the experiment. Each sample was air-dried and well mixed. Then 20 g of each sample was sieved through 100-mesh and about a 50 mg sample was weighed for analysis of the four elemental compositions by NAA. Results indicate that the REE tracers and NAA method can be used to not only quantitatively determine soil erosion amounts on different slope segments, but also to reveal the changeable process of rill erosion amount. All of the relative errors of the experimental results were less than 25%, which is considered satisfactory on the study of rill erosion process. 相似文献