全文获取类型
收费全文 | 428篇 |
免费 | 17篇 |
国内免费 | 4篇 |
专业分类
化学 | 283篇 |
晶体学 | 1篇 |
力学 | 12篇 |
数学 | 54篇 |
物理学 | 99篇 |
出版年
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 14篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 25篇 |
2011年 | 33篇 |
2010年 | 18篇 |
2009年 | 15篇 |
2008年 | 26篇 |
2007年 | 19篇 |
2006年 | 15篇 |
2005年 | 23篇 |
2004年 | 14篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 14篇 |
1998年 | 10篇 |
1996年 | 9篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1988年 | 6篇 |
1987年 | 1篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 4篇 |
1959年 | 1篇 |
排序方式: 共有449条查询结果,搜索用时 46 毫秒
41.
Elaine Smith Margaretta Taylor Maria Mendoza Julie Barkmeier Jon Lemke Henry Hoffman 《Journal of voice》1998,12(2):223-232
Patients at a university voice disorder clinic diagnosed with spasmodicdysphonia (SD, n = 68) or vocal fold paralysis (VFP, n = 57) reported vocal symptoms and adverse work outcomes in contrast to a nondisordered group (ND, n = 68). Patients with SD most frequently cited symptoms of effortfulness (57%) and weakness (54%), VFP cited hoarseness (70%) and weakness (60%), while the nondisordered reported hoarseness (28%). SD and VFP produced greater (p<.05) adverse work outcomes than the nondisordered in the past (SD: 65%, VFP: 41%, ND: 3%), potential future (SD: 78%, VFP: 65%, ND: 19%), and current job performance (SD: 64%, VFP: 46%, ND: 2%). These disorders significantly disrupt socioeconomic outcomes and research is needed to improve functional ability and quality of life. 相似文献
42.
SupposeM is a smooth manifold andV is a locally integrable vector subbundle of the complexified tangent bundle ofM. This paper explores the global unique continuation property of distribution solutions ofV, i.e., the distributionsu onM such thatLu = 0 wheneverL is a section ofV, and the closely related problem of the structure of the Sussmann orbits ofHV. 相似文献
43.
Franz‐Josef K. Rehmann Laurence P. Cuffe Oscar Mendoza Dilip K. Rai Nigel Sweeney Katja Strohfeldt William M. Gallagher Matthias Tacke 《应用有机金属化学》2005,19(3):293-300
Starting from 2‐furylfulvene (1a) , 2‐thiophenylfulvene (1b) , and 1‐methyl‐2‐pyrrolylfulvene (1c), [1,2‐di(cyclopentadienyl)‐1,2‐di‐(2‐furyl)ethanediyl] titanium dichloride (2a) , [1,2‐di(cyclopentadienyl)‐1,2‐di‐(2‐thiophenyl)ethanediyl] titanium dichloride (2b) , and [1,2‐di(cyclopentadienyl)‐1,2‐bis‐(1‐methyl‐2‐pyrrolyl)ethanediyl] titanium dichloride (2c) were synthesized. When titanocenes (2a–c) were tested against pig kidney carcinoma cells (LLC‐PK), inhibitory concentrations (50%) of 4.5 × 10?4 M , 2.9 × 10?4 M and 2.0 × 10?4 M respectively were observed. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
44.
A topological action for self-dual connections over noncompact Riemann surfaces is proposed. TheJ formulation and the associated linear system are obtained. A new connection is constructed, depending on a Kac-Moody parameter such that its flatness condition is theJ-equation associated to the self-dual problem. The algebra of infinitesimal Bäcklund transformations depending on this Kac-Moody parameter is constructed. 相似文献
45.
L. Mendoza Zélis E. Crespo M. Creus L. C. Damonte F. H. Sánchez G. Punte 《Hyperfine Interactions》1994,83(1):289-292
Pure crystalline Hf and Fe powders were mixed and milled under an argon atmosphere. The evolution of the system with milling time was followed with Mössbauer effect spectroscopy and X-ray diffraction. The results indicate that in the first stages an amorphous Fe-rich alloy was gradually formed together with a solid solution of Hf in Fe beyond the solubility limit. 相似文献
46.
47.
Elaine Smith Margaretta Taylor Maria Mendoza Jon Lemke Henry Hoffman 《Journal of voice》1998,12(4):551-558
Patients diagnosed with nodules (NO = 40) in a large university hospital clinic and an age-stratum matched nondiseased group (ND = 200) described adverse outcomes of vocal impairment on work and work-related communications. NOs were significantly more likely than NDs to report symptoms of hoarseness (73% vs. 26%), high-note difficulty (70% vs. 20%), difficulty speaking with a lower voice (53% vs. 13%) and a tired voice (50% vs. 10%), and their greatest source of physical discomfort was associated with scratchiness (61% vs. 3%). The average number of symptoms was four in NOs and less than one in NDs. Nodule patients were most concerned about the effects their voice problem would have on their future career (78% vs. 24%) and 49% of NOS reported their voice problem had an adverse work effect in the past compared with 4% of NDs. Having a voice condition limited current job performance in 39% of the NO group but only in 2% of the ND group. The results suggest that a diagnosis of nodules plays a major role in disrupting careers and work activities and that available educational programs and additional research are needed for improving their functional ability and preventing adverse outcomes in the lives of individuals with voice disorders. 相似文献
48.
49.
50.