全文获取类型
收费全文 | 2686篇 |
免费 | 134篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 14篇 |
妇产科学 | 18篇 |
基础医学 | 414篇 |
口腔科学 | 38篇 |
临床医学 | 209篇 |
内科学 | 159篇 |
皮肤病学 | 20篇 |
神经病学 | 376篇 |
特种医学 | 134篇 |
外科学 | 613篇 |
综合类 | 250篇 |
预防医学 | 362篇 |
眼科学 | 53篇 |
药学 | 110篇 |
2篇 | |
中国医学 | 28篇 |
肿瘤学 | 48篇 |
出版年
2024年 | 6篇 |
2023年 | 30篇 |
2022年 | 105篇 |
2021年 | 136篇 |
2020年 | 118篇 |
2019年 | 69篇 |
2018年 | 85篇 |
2017年 | 99篇 |
2016年 | 81篇 |
2015年 | 87篇 |
2014年 | 135篇 |
2013年 | 231篇 |
2012年 | 129篇 |
2011年 | 154篇 |
2010年 | 122篇 |
2009年 | 133篇 |
2008年 | 147篇 |
2007年 | 143篇 |
2006年 | 106篇 |
2005年 | 126篇 |
2004年 | 89篇 |
2003年 | 67篇 |
2002年 | 54篇 |
2001年 | 41篇 |
2000年 | 39篇 |
1999年 | 31篇 |
1998年 | 33篇 |
1997年 | 36篇 |
1996年 | 22篇 |
1995年 | 22篇 |
1994年 | 14篇 |
1993年 | 20篇 |
1992年 | 8篇 |
1991年 | 20篇 |
1990年 | 9篇 |
1989年 | 13篇 |
1988年 | 4篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1968年 | 1篇 |
排序方式: 共有2869条查询结果,搜索用时 31 毫秒
1.
2.
Kuo-yi Jade Chang MHealthEc MHM BSc Lisa Lorraine Dillon MSpecEd BPsych Lil Deverell COMS PhD MEd GradDipO&M BEd Mei Ying Boon PhD BOptom FAAO Lisa Keay PhD MPH BOptom 《Clinical & experimental optometry》2020,103(4):434-448
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual. 相似文献
3.
Guowei Zhang Fenger Sun Heping Liu Xiaoyan Ren Hong Xu Mingjie Wang Yizheng Fu 《Materials》2021,14(9)
The structural properties, elastic anisotropy, electronic structures and work function of D022-type Al3TM (TM = Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta) are studied using the first-principles calculations. The results indicate that the obtained formation enthalpy and cohesive energy of these compounds are in accordance with the other calculated values. It is found that the Al3Zr is the most thermodynamic stable compound. The mechanical property indexes, such as elastic constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and Vickers hardness are systematically explored. Moreover, the calculated universal anisotropic index, percent anisotropy and shear anisotropic factors of D022-type Al3TM are analyzed carefully. It demonstrates that the shear modulus anisotropy of Al3La is the strongest, while that of Al3Ta is the weakest. In particular, the density of states at Fermi level is not zero, suggesting that these phases have metal properties and electrical conductivity. More importantly, the mechanisms of correlation between hardness and Young’s modulus are further explained by the work function. Finally, the experimental design proves that D022-Al3Ta has an excellent strengthening effect. 相似文献
4.
5.
Heterosexual men and homosexual men rated how arousing different sexual fantasies were and how often they had used these fantasies
over the previous year. Within each group, sensual and genital same-orientation fantasies were more arousing than either public-sex
or dominance-submissive fantasies, which in turn were more arousing than aggressive-sex fantasies. For both heterosexual and
homosexual men the extent to which a fantasy was arousing correlated with the person's experience of the activity depicted
in the fantasy. The frequency of use of a fantasy correlated positively with its arousal level but not always subtantially
so. The results are discussed in the context of the mediating role of fantasy in human sexual arousal. 相似文献
6.
7.
Auditory Perception and the Control of Spatially Coordinated Action of Deaf and Hearing Children 总被引:1,自引:0,他引:1
G. J. P. Savelsbergh J. B. Netelenbos H. T. A. Whiting 《Journal of child psychology and psychiatry, and allied disciplines》1991,32(3):489-500
From birth onwards, auditory stimulation directs and intensifies visual orientation behaviour. In deaf children, by definition, auditory perception cannot take place and cannot, therefore, make a contribution to visual orientation to objects approaching from outside the initial field of view. In experiment 1, a difference in catching ability is demonstrated between deaf and hearing children (10-13 years of age) when the ball approached from the periphery or from outside the field of view. No differences in catching ability between the two groups occurred when the ball approached from within the field of view. A second experiment was conducted in order to determine if differences in catching ability between deaf and hearing children could be attributed to execution of slow orientating movements and/or slow reaction time as a result of the auditory loss. The deaf children showed slower reaction times. No differences were found in movement times between deaf and hearing children. Overall, the findings suggest that a lack of auditory stimulation during development can lead to deficiencies in the coordination of actions such as catching which are both spatially and temporally constrained. 相似文献
8.
L. Morino F. Bellomo P. Milano L. Bertignone M. Sabra 《Journal of orthopaedics and traumatology》2002,2(2):59-62
The authors, reviewing the international literature with their clinical experience developed in reconstructive surgery of
acetabular defects due to aseptic loosening of acetabular cups, suggest their guidelines to the right use of acetabular reinforcement
rings.
Received: 8 September 2001/Accepted: 4 November 2001 相似文献
9.
面神经管及其定位的研究 总被引:3,自引:0,他引:3
本文对80侧颞骨标本研究结果表明,面神经在内耳道、迷路段、水平段和垂直段的长度((?)±SD,mm)成人分别为:12.30±2.47、3.84±0.58、9.95±3.16、11.88±2.37;儿童为11.21±2.27、3.75±1.11、9.66±1.34、11.67±1.75,同时还观测了面神经管与周围结构的关系,为 Bell 面瘫减压术和面神经修补术提供了形态学依据。 相似文献
10.
Mitsuhiro Morita Harumoto Yamada Osamu Hemmi Kyosuke Fujikawa 《Journal of orthopaedic science》2004,9(1):99-102
In acetabular dysplasia of the hip joint accompanied by a giant acetabular bone cyst, rotational acetabular osteotomy may cause serious complications, such as bone necrosis after surgery or fracture of the fragile acetabulum during the operation. In a patient with this condition, we performed a two-stage operation: first, autogenous bone grafting supplemented with hydroxyapatite filling, then rotational acetabular osteotomy (after new bone formation had been assured). Radiographs and CT scans showed favorable fusion of the grafted bone. Some 18 months after the second operation, arthrograms showed no inflow of contrast medium from the articular cavity into the bone cyst region, although this had been observed before treatment. Thus, an effective remodeling of bony congruency was indicated in the mobile acetabulum 5 years after the second operation. This two-stage operation appears to be useful for correcting acetabular dysplasia accompanied by a giant bone cyst and to carry a reduced risk of serious complications, such as deterioration of the articular surface of the acetabulum or necrosis of the translocated acetabulum. 相似文献