全文获取类型
收费全文 | 1339篇 |
免费 | 22篇 |
国内免费 | 6篇 |
专业分类
化学 | 680篇 |
晶体学 | 14篇 |
力学 | 81篇 |
数学 | 115篇 |
物理学 | 477篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 21篇 |
2019年 | 19篇 |
2018年 | 15篇 |
2017年 | 21篇 |
2016年 | 27篇 |
2015年 | 18篇 |
2014年 | 41篇 |
2013年 | 81篇 |
2012年 | 70篇 |
2011年 | 71篇 |
2010年 | 46篇 |
2009年 | 56篇 |
2008年 | 60篇 |
2007年 | 54篇 |
2006年 | 42篇 |
2005年 | 44篇 |
2004年 | 36篇 |
2003年 | 28篇 |
2002年 | 16篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1996年 | 14篇 |
1995年 | 20篇 |
1994年 | 14篇 |
1993年 | 22篇 |
1992年 | 19篇 |
1991年 | 20篇 |
1990年 | 13篇 |
1989年 | 21篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 17篇 |
1984年 | 20篇 |
1983年 | 17篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 15篇 |
1979年 | 20篇 |
1978年 | 15篇 |
1977年 | 19篇 |
1976年 | 20篇 |
1975年 | 12篇 |
1974年 | 10篇 |
1973年 | 10篇 |
1936年 | 13篇 |
排序方式: 共有1367条查询结果,搜索用时 0 毫秒
101.
102.
103.
The normal-superfluid phase-transition temperature of a dilute Bose system whose particles interact via a two-body potential composed of a hard core followed by a weak attractive tail is studied using the three-level approximation. It is found that, for such a system, the three-level approximation does give results, for the transition temperature, approximately equal to the lambda-transition temperature of liquid 4He. The condensed state is composed of ε0 = 0, ε1 = E0/N and ε2, such that the states ε0 and ε1 lie below the cutoff momentum. 相似文献
104.
105.
S.K. Khanna E.R. Falardeau A.J. Heeger J.E. Fischer 《Solid State Communications》1978,25(12):1059-1065
An initial survey of the conduction electron spin resonance is presented for a series of graphite compounds intercalated with acceptor molecules: stages 1–3 AsF5, stages 2–5 HNO3, and stage 2 Br2 and ICl. The g-values and lineshapes were studied as functions of temperature and concentration. The results suggest metallic behavior but with very small density of states at the Fermi energy: N(EF) ~1020/cm3 eV. The temperature dependence of the linewidth is dominated by an order-disorder transition of the intercalant layers, implying that the conduction electrons are not entirely confined to the graphite portion of the crystal. The decrease in g-value anisotropy upon intercalation can be understood in terms of Elliott's theory. 相似文献
106.
The composition of the precipitate formed when the Nessler's reagent is treated with ammonia, is assumed as NHn-1Hg2In, aq. and has been studied potentiometrically from iodine-hypoiodite-system. It has been observed that the value of n depends on the concentrations of [HgI4]-2 and OH- ions as well as on the amount of ammonia added and it may vary from 1 to 3. The colour of the precipitate deepens from brown to chocolate as the value of n increases. 相似文献
107.
We develop models for the propagation of intense pulses in solid state media which can have either saturated absorption or reverse absorption. We model subluminal propagation in ruby and superluminal propagation in alexandrite as three and four level systems, respectively, coupled to Maxwell's equations. We present results well beyond the traditional pump-probe approach and explain the experiments of Bigelow et al. [Phys. Rev. Lett. 90, 113903 (2003)]Science 301, 200 (2003)]] on solid state materials. 相似文献
108.
Magnetization relaxation processes, which are represented by the Gilbert damping term and the spin torque term in the Landau-Lifshitz-Gilbert (LLG) equation, are described by the radiation-spin interaction (RSI), where the radiation field is produced by magnetization precessional motion itself. It is shown that the LLG equation including the Gilbert damping term and the spin torque term is derived from the spin Hamiltonian containing the RSI. The derivation of the LLG equation is given in a self-consistent method. It is also shown that, according to RSI, the magnitude of the magnetization vector deviates from the magnetization saturation with the order of O(alpha(2)), where alpha is the Gilbert damping parameter. 相似文献
109.
In this review article, we discuss a class of biosensors that exploit the change in the colorimetric properties of noble metal nanoparticles in response to biomolecular binding at their surface. Several sensor fabrication techniques as well as sensor configurations are discussed with an emphasis on their strengths and limitations. We conclude by presenting the future prospects and challenges for the successful transition of this technology from the laboratory to a commercial product. 相似文献
110.
A solution phase UV-irradiation technique has been exploited to produce an AuSe nanoalloy through fusion of preformed Au (photoproduced) and Se (chemically prepared) in a micellar (TX-100) medium. 相似文献