全文获取类型
收费全文 | 627篇 |
免费 | 5篇 |
国内免费 | 11篇 |
专业分类
化学 | 240篇 |
晶体学 | 2篇 |
力学 | 15篇 |
数学 | 133篇 |
物理学 | 253篇 |
出版年
2020年 | 4篇 |
2019年 | 4篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 27篇 |
2012年 | 19篇 |
2011年 | 25篇 |
2010年 | 16篇 |
2009年 | 9篇 |
2008年 | 26篇 |
2007年 | 23篇 |
2006年 | 14篇 |
2005年 | 28篇 |
2004年 | 17篇 |
2003年 | 17篇 |
2002年 | 25篇 |
2001年 | 12篇 |
2000年 | 19篇 |
1999年 | 12篇 |
1998年 | 8篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1993年 | 16篇 |
1992年 | 17篇 |
1991年 | 17篇 |
1990年 | 21篇 |
1989年 | 12篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 20篇 |
1984年 | 6篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 5篇 |
1974年 | 9篇 |
1973年 | 6篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有643条查询结果,搜索用时 31 毫秒
81.
Ermolina I. V. Krushelnitsky A. G. Ivoylov I. N. Feldman Yu. D. Fedotov V. D. 《Applied magnetic resonance》1993,5(3-4):265-283
Applied Magnetic Resonance - Non-selective NMR relaxation of protein and water protons at various resonance frequencies as well as Time Domain Dielectric Spectroscopy (TDDS) were applied to study... 相似文献
82.
83.
N.I. Feldman 《Journal of Number Theory》1977,9(1):48-60
The estimate from below of the modulus of the difference between π and algebraic numbers from the fields generated by the roots of unity is made. 相似文献
84.
J. C. White D. Henderson M. Slatkine I. J. Bigio B. J. Feldman R. A. Fisher F. K. Tittel W. L. Wilson Jr. R. A. Williams G. Marowsky M. J. Shaw F. O'Neill C. B. Edwards D. J. Nicholas D. Craddock P. H. Bucksbaum J. Bokor R. H. Storz S. G. Dinev H. -U. Daniel H. Walther F. Kvasnik T. A. King Qiu Mingxin Zhou Zhenzhuo 《Applied physics. B, Lasers and optics》1982,28(2-3):124-130
85.
We review recent results in electron-positron annihilation above a center-of-mass energy of 2 GeV with particular emphasis on the production and properties of new particles. Topics include the total e+e? cross section, the properties of jet-like structure in high energy multi-particle events, the properties of the Ψ family of charmonium states, the production and properties of the charmed D mesons, and evidence for and the properties of the τ, a new charged lepton. 相似文献
86.
Robert Thayer Sataloff Marc Feldman Kathe S. Darby Linda M. Carroll Joseph R. Spiegel Barbara-Ruth Schiebel 《Journal of voice》1988,1(4):368-377
Arytenoid dislocation is a common yet infrequently diagnosed complication of laryngeal trauma. It may result in various symptoms, including permanent dysphonia, although immediate voice change is not always present. Early reduction is the treatment of choice; however, late reduction is often successful in restoring voice. A high index of suspicion based on the history of the patient is necessary to recognize arytenoid dislocation. Thorough physical examination and objective tests are helpful in confirming this diagnosis. 相似文献
87.
Conditions were studied for the determination of trace amounts of chromium by atomic absorption spectroscopy. Solution matrix, flame composition, and extraction procedures were the variables studied. A detection limit of 0.006 p.p.m. of chromium was observed with an air-hydrogen flame and methyl isobutyl ketone as the solvent. 相似文献
88.
J.L. Feldman 《Journal of Physics and Chemistry of Solids》1976,37(12):1141-1144
Recent neutron data on the dispersion curves and X-ray measurements of the linear compressibilities of the 2H polytypes of MoS2 and NbSe2 have been used to obtain approximate values of the five independent elastic constants of these materials. In the case of NbSe2 sufficient information is available to over-determine the elastic constants and the results are self consistent within estimated uncertainties, although the uncertainties are especially large for c33 and c11. Additional related considerations such as Debye temperatures and model calculations of c33, and c44 are also made. It is found that there is significant and unexplained disagreement between the value of the low temperature specific heat Debye temperature of NbSe2 and the value determined on the basis of the elastic constants, but that the model predictions of c33 and c44 are in satisfactory agreement with the values extracted from the neutron data for both MoS2, and NbSe2. 相似文献
89.
In the last years molecular beam epitaxy (MBE) has become a very important method to create new materials. Scattering and channeling of high-energy ions is a mass-dispersive, surface-sensitive crystallographic technique, particularly suited for the investigation of epitaxial systems. The combination of both techniques allows new insight into some of the fundamental processes at interfaces and surfaces. As an example we discuss the influence of substrate reconstruction on epitaxial growth. We show for the Si/Ge and Si/Si systems that the reordering of the reconstruction-induced displacements at the substrate surface, a necessary condition for epitaxial growth, is critically dependent on the type of reconstruction: Deposition of Ge or Si on Si(100)2×1 at room-temperature relieves the reconstruction, whereas Si(111)7×7 appears unaffected. This difference is discussed in terms of structural models for these surfaces. We shall also discuss the implications of these results with respect to MBE and, in particular, to Si homoepitaxial temperatures. 相似文献
90.
Barry J. Feldman 《Optics Communications》1975,14(1):13-16
Theoretical studies are presented for the amplification and compression of multiline short pulses of CO2 laser radiation at 10.6 μ in a high gain, CO2 laser amplifier. A method of efficiently generating high energy, subnanosecond pulses of CO2 laser radiation is proposed utilizing a pulse tailoring technique recently disclosed by Figueira and Sutphin. 相似文献