全文获取类型
收费全文 | 32274篇 |
免费 | 2929篇 |
国内免费 | 1234篇 |
专业分类
耳鼻咽喉 | 122篇 |
儿科学 | 177篇 |
妇产科学 | 212篇 |
基础医学 | 2365篇 |
口腔科学 | 768篇 |
临床医学 | 3615篇 |
内科学 | 1834篇 |
皮肤病学 | 248篇 |
神经病学 | 787篇 |
特种医学 | 784篇 |
外科学 | 2039篇 |
综合类 | 7356篇 |
现状与发展 | 2篇 |
预防医学 | 3916篇 |
眼科学 | 285篇 |
药学 | 6011篇 |
181篇 | |
中国医学 | 5208篇 |
肿瘤学 | 527篇 |
出版年
2024年 | 200篇 |
2023年 | 503篇 |
2022年 | 1317篇 |
2021年 | 1566篇 |
2020年 | 1330篇 |
2019年 | 767篇 |
2018年 | 722篇 |
2017年 | 1034篇 |
2016年 | 1150篇 |
2015年 | 1169篇 |
2014年 | 2303篇 |
2013年 | 2320篇 |
2012年 | 2343篇 |
2011年 | 2458篇 |
2010年 | 1854篇 |
2009年 | 1508篇 |
2008年 | 1541篇 |
2007年 | 1784篇 |
2006年 | 1338篇 |
2005年 | 1136篇 |
2004年 | 967篇 |
2003年 | 776篇 |
2002年 | 671篇 |
2001年 | 594篇 |
2000年 | 524篇 |
1999年 | 478篇 |
1998年 | 399篇 |
1997年 | 337篇 |
1996年 | 337篇 |
1995年 | 319篇 |
1994年 | 312篇 |
1993年 | 299篇 |
1992年 | 255篇 |
1991年 | 228篇 |
1990年 | 212篇 |
1989年 | 191篇 |
1988年 | 180篇 |
1987年 | 160篇 |
1986年 | 154篇 |
1985年 | 166篇 |
1984年 | 102篇 |
1983年 | 68篇 |
1982年 | 102篇 |
1981年 | 57篇 |
1980年 | 49篇 |
1979年 | 31篇 |
1978年 | 29篇 |
1977年 | 21篇 |
1976年 | 25篇 |
1974年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
内眦赘皮与重睑成形同期手术的一种新方法 总被引:12,自引:1,他引:11
目的 探索适合同时行重睑成形术和内眦赘皮矫正术的新方法。方法 根据内眦赘皮深部眼轮匝肌结构上的异常特点,遵循内眦赘皮的上睑(倒向性内眦赘皮除外)内侧睑缘处皮肤短缺和尽量减少局部皮肤瘢痕的原则,设计适合同时行重睑成形术的新内眦赘皮矫正术(反Stallard法)。结果 临床应用86例,进行了为期6个月以上的随访,结果所有患者的重睑为稳定性平行型重睑,内眦已完全或大部分开大,手术效果满意。结论 此内眦赘皮矫正术能够充分矫正内眦部结构上的异常,而且适合与重睑成形术同期施行,是一种效果稳定,结果满意的术式。 相似文献
62.
Cholecystokinin (CCK )isa polypeptidehor monecontaining 33aminoacidsresiduewithgastroin testinal,biliarandbrainactivities Itiswidelydis tributedinthevertebratecentralnervoussystem ,anditcanstimulateextensivelytheliberationofinsulinandglucagonfromtheLangerhansislets GreateffortshavebeendevotedtothesynthesisofCCK 8,itsderivativesandanalogues Amongthedifferentmethods ,theenzymaticmethodisthemosteffectiveonewithmanyadvantagesoverconventionalchemicalmethodologies :enzymespecificitysuppress essid… 相似文献
63.
目的 采用反向Fick氏法和间接测热法测定心脏手术后病人的全身氧耗,并比较两种测量方法的相关性和准确性。方法8例心脏手术术后病人,分别在入ICU后2h和6h时同时采用反向Fick氏和间接测热法测定病人的全身氧耗量。结果 间接测热法和反向Fick法测得氧耗分别是(16±30)ml·min-1·m-2和(127±23)ml·min-1·m-2,前者的测定结果显著高于后者(P<0.01)。相关分析显示两者有较好的相关性(r=0.92,P<0.01)。采用Bland和Altman统计分析提示两种测定结果的平均偏离值为(35.5±13.4)ml·min-1·m-2,其95%的分布范围是(9~62)ml·min-1·m-2,提示两种测量结果间的一致性较差。结论 两种方法测定心脏病人术后全身氧耗的结果有明显差异,其中反向Fick氏法的测定结果误差大、准确性差,而间接测热法是较好的临床选择。 相似文献
64.
52例电烧伤的治疗分析 总被引:1,自引:1,他引:0
目的:总结电烧伤的治疗方法。方法:对52例资料齐全的电烧伤病人的治疗方法及疗效进行回顾性分析。结果:单纯电火花烧伤的治疗和一般烧伤相同,电击伤多为早期清创,植皮覆盖创面。结论:电烧伤创面根据情况可有多种治疗方法:包括单纯换药,湿润烧伤膏,中厚皮片移植,皮瓣移植等。 相似文献
65.
Purpose. To determine the statistical variability expected for a well designed HPLC assay of a bulk drug substance (BDS). The results are used to develop appropriate acceptance criteria for a method validation protocol as well as to evaluate the level of uncertainty expected for assay results using a variety of sampling/injection schemes.
Methods. Computer simulation was used to generate a large quantity of data and the variability of the mock results was evaluated. Error propagation was also calculated, whenever possible, to confirm results obtained from the simulations.
Results. Protocol acceptance criteria were developed that were consistent with the expected variability for data resulting from the execution of the validation protocol. In certain cases simulations provided the only avenue of obtaining results that could not otherwise be readily determined.
Conclusions. Computer modeling can be used to obtain suitable acceptance criteria for validation results which are consistent with method variability. This is particularly significant in the case of linearity where it has been difficult to develop acceptance criteria based on anything other than analyst intuition and experience. Assay simulations clearly demonstrated that the variability expected for a typical BDS assay is large relative to the average specification range and therefore little insight about relative purity can be gained comparing individual passing assay results. 相似文献
66.
Julian J. Faraway 《Genetic epidemiology》1993,10(4):225-233
An improved sib-pair test for linkage is introduced which is superior to the previously proposed tests. The test is derived from the standard chi-squared goodness of fit statistic by restricting the alternative hypothesis to the genetically possible. Critical values are given and exact power comparisons are made with the previously proposed tests. The new test is shown to be more powerful for finite samples as well as being asymptotically uniformly most powerful. © 1993 Wiley-Liss, Inc. 相似文献
67.
68.
Lars Bendtsen Rigmor Jensen Jannick Brennum Lars Arendt-Nielsen Jes Olesen 《Cephalalgia : an international journal of headache》1993,13(3):184-191
The duration of the late exteroceptive suppression period (ES2 ) of temporal muscle EMG activity has been reported to be reduced in patients suffering from chronic tension-type headache. Methods of recording and analysing ES2 have varied between centers and reproducibility of results within subjects , although insufficiently studied, has generally been poor. ES2 was investigated in 30 healthy subjects, using a computerized technique of recording, rectifying and averaging the EMG signals. Hour to hour and week to week variations of ES2 durations were calculated, and the influence of pain during a cold pressor test and of sustained muscle contraction on ES2 durations was investigated. The intra-individual variation of ES2 durations was 16.0% from hour to hour and 20.7% from week to week. The inter-individual variation was 36.7%. The present method for analysis of ES2 periods proved to be reliable, as the intra-observer variation was 4.2% and the inter-observer variation 4.6%. ES2 periods were significantly shorter on the first compared to the second day of examination ( p = 0.006) and during experimental pain ( p = 0.0005). We recommend the use of the computerized averaging technique in future studies and caution against the dependence of results upon factors such as conditioning and pain. 相似文献
69.
本文报道pH指示剂吸收度比值法测定盐酸乙胺丁醇的含量。该法采用指示剂为0.05%茜素黄R,测定波长374nm和500nm;标准液为0.1mol/L NaOH;仪器为WFZ-800D_2型分光光度计。测得三批盐酸乙胺丁醇的含量分别为99.5±0.04%,99.4±0.05%和99.6±0.03%.同时与药典法比较,结果一致。 相似文献
70.
新Vierordt法测定鲁南贝特片中两组分的含量 总被引:1,自引:0,他引:1
目的测定鲁南贝特片中氯唑沙宗和对乙酰氨基酚的含量。方法采用新Vierordt法不经提取分离直接测定两组分的含量 ,测定波长λ1=2 4 3.9nm ,λ2 =2 5 7.6nm。结果氯唑沙宗线性范围为 (8.4 7~ 4 2 .36 ) μg/ml,r=0 .9990 ,对乙酰氨基酚线性范围为 (8.83~ 4 4 .16 ) μg/ml,r =0 .9994 ,氯唑沙宗和对乙酰氨基酚的平均回收率和相对标准偏差分别为 10 0 .1%、0 .89%和 10 0 .6 %、0 .4 4 %。结论该方法简便、快速、重现性好 ,可消除两组分的相互干扰 ,结果满意。 相似文献