全文获取类型
收费全文 | 1428篇 |
免费 | 130篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 75篇 |
妇产科学 | 20篇 |
基础医学 | 158篇 |
口腔科学 | 34篇 |
临床医学 | 148篇 |
内科学 | 316篇 |
皮肤病学 | 38篇 |
神经病学 | 87篇 |
特种医学 | 155篇 |
外科学 | 166篇 |
综合类 | 53篇 |
一般理论 | 1篇 |
预防医学 | 63篇 |
眼科学 | 52篇 |
药学 | 99篇 |
中国医学 | 9篇 |
肿瘤学 | 90篇 |
出版年
2023年 | 10篇 |
2022年 | 31篇 |
2021年 | 41篇 |
2020年 | 30篇 |
2019年 | 41篇 |
2018年 | 66篇 |
2017年 | 28篇 |
2016年 | 52篇 |
2015年 | 52篇 |
2014年 | 65篇 |
2013年 | 86篇 |
2012年 | 87篇 |
2011年 | 69篇 |
2010年 | 64篇 |
2009年 | 76篇 |
2008年 | 60篇 |
2007年 | 63篇 |
2006年 | 57篇 |
2005年 | 52篇 |
2004年 | 28篇 |
2003年 | 37篇 |
2002年 | 32篇 |
2001年 | 17篇 |
2000年 | 10篇 |
1999年 | 15篇 |
1998年 | 42篇 |
1997年 | 45篇 |
1996年 | 42篇 |
1995年 | 40篇 |
1994年 | 22篇 |
1993年 | 30篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 18篇 |
1988年 | 16篇 |
1987年 | 10篇 |
1986年 | 14篇 |
1985年 | 14篇 |
1984年 | 8篇 |
1983年 | 15篇 |
1982年 | 5篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 3篇 |
1884年 | 1篇 |
排序方式: 共有1569条查询结果,搜索用时 15 毫秒
1.
Pankaj Dabir Snehal Dabir B V Siva Prasad M V R Reddy 《Infection, genetics and evolution》2006,6(4):287-291
Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response. 相似文献
2.
Zongli Lin Meir Pachter Siva Banda Yacov Shamash 《Optimal control applications & methods.》2002,23(1):21-43
A design technique (Control of Uncertain Systems with Bounded Inputs, Tarbouriech S, Garcia G, (Eds), Lecture Notes in Control and Information Sciences, vol. 227 , Springer: Berlin, 1997; 173–186) recently proposed for stabilization of a linear system with rate‐limited actuators is utilized to design feedback laws that cause the system output to track a desired command signal. This design technique combines two design techniques recently developed for linear systems with position limited actuators, piecewise‐linear LQ control (Automatica, 1994; 30 : 403–416) and low‐and‐high gain feedback (IEEE Trans. Automat. Control, 1996; 41 : 368–378), and hence takes advantage of both design techniques, while avoiding their disadvantages. In the case that only the output is available for feedback, the performance of the state feedback law is preserved by the use of a fast observer. An open‐loop exponentially unstable fighter aircraft is used to demonstrate the effectiveness of the proposed control design method. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
3.
4.
Andrew G. Sparks Hsi-Han Yeh Siva S. Banda 《Optimal control applications & methods.》1990,11(4):307-325
This paper introduces a design methodology for a dynamic compensator that simultaneously minimizes the upper bound of a quadratic performance index and the H∞-norm of a disturbance transfer function matrix of a multiple-input/multiple-output system whose model contains parameter uncertainty in the state and input matrices. The real parameter uncertainty is modelled as additional measurement outputs and as additional weights on the existing noise inputs and measurement outputs of the system. The compensator equations are derived by taking the dual of a system with parameter variation in the state and output matrices, for which the compensator equations have previously been derived, and then taking the dual of the compensator equations. An algorithm for applying this theory is given and an example is shown. 相似文献
5.
6.
7.
Transient Osteoporosis of the Hip in Pregnancy 总被引:1,自引:0,他引:1
Sashi Siva Vijay Roach 《The Australian & New Zealand journal of obstetrics & gynaecology》1997,37(3):261-266
Summary: Transient osteoporosis of the hip (TOH) is an uncommon condition. This painful regional osteoporosis affects previously healthy women in the third trimester of pregnancy. It is characterized by pain in the affected hip and pronounced osteopenia of the femoral head and neck. It has a relatively short clinical course (average 6 months) and a predictably benign prognosis. Complete clinical and radiological recovery is the rule. The diagnosis is one of exclusion. The cause of the osteopenia is not known, although various aetiological factors have been implicated. A case of TOH occurring in the third trimester of pregnancy with complete recovery within 6 months postpartum is presented. 相似文献
8.
9.
10.
Siva Narayanan John Van Vleet Billy Strunk Robert N Ross Mikel Gray 《Journal of wound, ostomy, and continence nursing》2005,32(3):163-170
This study compared clinical outcomes and nursing labor costs associated with (a) balsam Peru, hydrogenated castor oil, and trypsin (BCT) ointment; (b) BCT + Other; and (c) Other treatments in 2014 wound episodes occurring in 861 patients (mean 2.34 wounds/patient). Treatment with BCT ointment or BCT + Other was associated with a higher healing rate (P < .05). No Stage 1 or 2 ulcer treated with BCT ointment progressed, compared with 13.8% treated with BCT + Other and 13.4% treated with Other. The reported mean duration of treatment and time to heal were shorter for ulcers treated with BCT ointment, but differences did not reach significance, possibly because of the variability in reported treatment times. Mean daily nursing labor costs were lower for treatment with BCT than Other ($50.8 vs $61.7, P < .05). These data suggest that treatment of Stage 1 or 2 ulcers with BCT may be associated with shorter treatment time and time to heal and a potential reduction in treatment-related nursing labor costs. 相似文献