全文获取类型
收费全文 | 14526篇 |
免费 | 1361篇 |
国内免费 | 884篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 81篇 |
妇产科学 | 62篇 |
基础医学 | 738篇 |
口腔科学 | 196篇 |
临床医学 | 1151篇 |
内科学 | 851篇 |
皮肤病学 | 151篇 |
神经病学 | 415篇 |
特种医学 | 269篇 |
外科学 | 445篇 |
综合类 | 2763篇 |
现状与发展 | 1篇 |
预防医学 | 1315篇 |
眼科学 | 235篇 |
药学 | 5074篇 |
28篇 | |
中国医学 | 2627篇 |
肿瘤学 | 280篇 |
出版年
2024年 | 73篇 |
2023年 | 195篇 |
2022年 | 365篇 |
2021年 | 489篇 |
2020年 | 490篇 |
2019年 | 428篇 |
2018年 | 456篇 |
2017年 | 502篇 |
2016年 | 521篇 |
2015年 | 545篇 |
2014年 | 971篇 |
2013年 | 1062篇 |
2012年 | 1112篇 |
2011年 | 1136篇 |
2010年 | 862篇 |
2009年 | 732篇 |
2008年 | 696篇 |
2007年 | 853篇 |
2006年 | 750篇 |
2005年 | 651篇 |
2004年 | 525篇 |
2003年 | 482篇 |
2002年 | 421篇 |
2001年 | 386篇 |
2000年 | 324篇 |
1999年 | 241篇 |
1998年 | 191篇 |
1997年 | 188篇 |
1996年 | 161篇 |
1995年 | 136篇 |
1994年 | 127篇 |
1993年 | 93篇 |
1992年 | 101篇 |
1991年 | 76篇 |
1990年 | 58篇 |
1989年 | 51篇 |
1988年 | 52篇 |
1987年 | 36篇 |
1986年 | 35篇 |
1985年 | 31篇 |
1984年 | 32篇 |
1983年 | 25篇 |
1982年 | 26篇 |
1981年 | 17篇 |
1980年 | 15篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1974年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
研究了吡哌酸与四氯苯醌间的荷移反应.两者在硼砂缓冲溶液中形成1∶1的络合物,其λ_(max)为330.8nm,摩尔吸光系数ε=1.66×10~4,RSD为2.2%。用于测定制剂含量,结果与药典方法一致。 相似文献
42.
Emad Dean Nukta Bernhard Meier Philip Urban Thierry Muller Pierre A. Dorsaz Josiane Favre 《Catheterization and cardiovascular interventions》1992,25(4):272-277
The Magnum system, initially designed for coronary angioplasty (PTCA) of chronic total occlusion, consists of a balloon catheter and a solid steel 0.021 inch (0.53 mm) steerable and removable wire with a soft and moldable distal portion, tipped with a 1 mm olive. To evaluate its performance in routine PTCA, 200 unselected consecutive patients were randomized to two equal groups, i.e., group Magnum (100 patients, 115 vessels) and group Standard (100 patients, 118 vessels) including 18 and 21 patients with chronic total occlusions, respectively. Randomization was performed by the sealed envelope system in the catheterization laboratory and crossover of system was imposed if it was not possible to place a balloon correctly within 20 min of fluoroscopy time. There were no significant differences between groups concerning clinical and angiographic baseline characteristics, size of initial balloons (3.0±0.3 mm in both groups), fluoroscopy time to cross the lesion with the wire (Magnum: 4±5, Standard: 5±6 min), total fluoroscopy time (Magnum: 11 ± 9, Standard: 12±12 min), and need for crossover (Magnum: 10%, Standard: 16%). Success rates per lesion were comparable with 90% in group Magnum and 84% in group Standard, as were the complications with one inhospital death in group Standard, occurring three weeks after PTCA and stent implantation. There was no emergency operation. Six patients per group had myocardial infarction of whom two in group Magnum and one in group Standard developed a Q-wave. The following variables were significantly in favor of the Magnum system compared with the Standard system: success rate in nontotal lesions (97% versus 90%) crossover success in total occlusions (0 vs. 33%), fluoroscopy time to cross the lesion with the balloon once the wire was in place (1 ± 2 vs. 2 ± 4 min), and use of a single versus 1.2±0.5 wires per lesion. The only advantage of the Standard systems was the more common use of 7 French guiding catheters (Magnum: 40%, Standard: 53%, p = 0.09). The Magnum system compares favorably with standard systems for routine PTCA. The robust design of the Magnum wire does not impair ease of placement and safety but saves material and facilitates balloon advancement across the lesion. 相似文献
43.
复方金银花擦剂中没食子酸的含量测定 总被引:2,自引:0,他引:2
目的:建立测定复方金银花擦剂中没食子酸的含量测定方法。方法:Novapak C18色谱柱,流动相甲醇冰醋酸-二甲基酰胺-水(2:0.5:20:90),检测波长275nm。结果:该法线性关系良好,相关系数r=0.9996,加样回收率为99.02%,RSD=1.94%。结论:该方法操作简单,分离效果好,可用于复方金银花擦剂的质量控制。 相似文献
44.
45.
Kawashima Yoshiaki Cui Fude Takeuchi Hirofumi Niwa Toshiyuki Hino Tomoaki Kiuchi Katsumi 《Pharmaceutical research》1995,12(7):1040-1044
Purpose. Poorly compressible crystals of acebutolol hydrochloride were agglomerated by the spherical crystallization technique with a two-solvent system to improve the compressibility for direct tabletting. The mechanism of improvements in static compression behaviors and tablettabilities of the spherically agglomerated crystals were investigated.
Methods. The improvement of static compression behaviors of the agglomerated crystals was determined by measuring the stress relaxations and elastic recoveries of compressed powder of original and agglomerated crystals. The improved tablettability of agglomerated crystals was evaluated by the pressure transmission ratio upon compression, the ejection pressure for releasing the tablet from the die and the tablet strength, i.e., tensile strength required for breaking.
Results. The higher relaxation pressure and the lower elastic recovery of the agglomerated crystals than of the original crystals were found. The pressure transmission ratio data showed that the friction pressures of the two crystals were similar during the compression period. The ejection pressure of the agglomerated crystals was lower than that of the original crystals. The tensile strength of the tablet of agglomerated crystals was greater than that of the original crystals.
Conclusions. The compressibility and tablettability of the spherically agglomerated crystals prepared by the spherical crystallization technique were much improved due to their increased plastic property and reduced adhesive property compared to the original crystals. 相似文献
46.
47.
采用1,1,2-三氯乙烷作溶剂,三乙胺作相转移催化剂合成了吡喹酮的重要中间体1-氰基-2-苯甲酰-1,2-二氢异喹啉。本法单耗低,产物质量好。Reissert 反应收率由文献报道的82%提高至90%。 相似文献
48.
我院自2002年2月至2003年10月期间施行脑动脉瘤手术18例。现将麻醉处理体会,并结合文献总结如下。 相似文献
49.
生物胶复合物加解剖钢板内固定治疗胫骨平台骨折 总被引:3,自引:0,他引:3
目的探讨生物胶复合物加解剖钢板内固定治疗胫骨平台骨折的临床效果。方法采用切开复位、生物胶复合物植骨加解剖型支撑钢板内固定治疗胫骨平台骨折28例,受伤至手术时间5~10d,植入复合物量为3~8g。结果所有患者均获随访,随访6~24个月,全部骨折均获得临床愈合,未见关节面下陷,生物胶复合物中羟基磷灰石未见移动及吸收,治疗效果参照M echant评分标准,优13例,良11例,可3例,差1例,总优良率达85.3%。结论生物胶复合物加解剖钢板内固定治疗胫骨平台骨折的临床效果良好。生物胶复合物具有较强的成骨能力,可修复骨缺损。 相似文献
50.
研究了卡尔曼滤波紫外分光光度法测定复方新诺明片和增效联磺片中各组分的实验条件,结果复方新诺明片平均回收率分别为100.4±0.2%(SMZ)和100.4±0.5%(TMP);增效联磺片平均回收率分别为99.5±0.7%(SMZ)、100.8±0.6%(SD)和99.2±0.6%(TMP)。 相似文献