全文获取类型
收费全文 | 665篇 |
免费 | 21篇 |
国内免费 | 2篇 |
专业分类
化学 | 415篇 |
晶体学 | 3篇 |
力学 | 29篇 |
数学 | 72篇 |
物理学 | 169篇 |
出版年
2022年 | 7篇 |
2021年 | 14篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 19篇 |
2015年 | 17篇 |
2014年 | 20篇 |
2013年 | 39篇 |
2012年 | 53篇 |
2011年 | 56篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 40篇 |
2007年 | 42篇 |
2006年 | 32篇 |
2005年 | 39篇 |
2004年 | 21篇 |
2003年 | 19篇 |
2002年 | 21篇 |
2001年 | 6篇 |
2000年 | 15篇 |
1999年 | 9篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 10篇 |
1977年 | 2篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1926年 | 2篇 |
排序方式: 共有688条查询结果,搜索用时 15 毫秒
81.
Below T2 = 202 K, in the incommensurate phase, a Debye relaxation appears for c33; it can be attributed to a linear coupling between an acoustical mode and a phason. The relaxation time is τ = τ0/(T0?T) with τ0 = 6.2 x 10?12 sec deg and T0 = 200.9 K. The same phenomenon appears more weakly for c11. The c66 elastic constant has a double discontinuity around T1 = 169 K; this shows that in the vicinity of T1 there are two transitions, separated by a temperature interval of 3°. 相似文献
82.
83.
Benoit Kloeckner 《Transformation Groups》2006,11(2):185-194
The group of direct isometries of the hyperbolic space
This isometric action admits many differentiable compactifications into an action on the closed n-dimensional ball. We prove
that all such compactifications are topologically conjugate but not necessarily differentiably conjugate. We give the classifications
of real analytic and smooth compactifications. 相似文献
84.
A. Benoit M. Chapellier G. Chardin L. Dumoulin K. Eitel J. Gascon G. Gerbier C. Goldbach J. Jochum A. de Lesquen G. Nollez F. Pröbst W. Seidel 《Physics letters. [Part B]》2006
The ZEPLIN Collaboration has recently published its first result presenting a maximum sensitivity of 1.1×10−6 picobarn for a WIMP mass of ≈60 GeV. The analysis is based on a discrimination method using the different time distribution of scintillation light generated in electron recoil and nuclear recoil interactions. We show that the methodology followed both for the calibration of the ZEPLIN-I detector response and for the estimation of the discrimination power is not reliable enough to claim any background discrimination at the present stage. The ZEPLIN-I sensitivity appears then to be in the order of 10−3 picobarn, three orders of magnitude above the claimed 1.1×10−6 picobarn. 相似文献
85.
Desjardins Benoit 《偏微分方程通讯》2013,38(11-12):1667-1703
86.
Habauzit D Armengaud J Roig B Chopineau J 《Analytical and bioanalytical chemistry》2008,390(3):873-883
Estrogenic compounds are a class of pharmaceutical products harmful to animals and a cause of environmental damage. The biological
activity of these compounds is high since they have been designed to act at low concentrations. Thus, even at the low concentrations
found in the environment, they may produce deleterious effects on aquatic organisms as well as on humans, who might be contaminated
in a number of ways (via drinking water or contaminated food, for example). We used the property of these compounds to bind
a specific protein (estrogen receptor, ER) to develop a quantification method of these chemical entities. Estrogenic compound
detection was performed using ER dimerization properties monitored by surface plasmon resonance (SPR). The ligand-activated
ER dimer was detected by its interaction with a specific DNA consensus sequence estrogen response element. The concentration
and the nature of the estrogenic compounds modified the SPR signal and were characteristic of the ligand-dependent homodimerization
of ER. For 17β-estradiol, dimerization of ER was experimentally determined at an ER to 17β-estradiol ratio near 1:1. Estrogenic
compounds (17β-estradiol, estriol, estrone, ethynyl estradiol) activated the dimerization process at different concentration
levels, while some others (tamoxiphen, resveratrol, genistein, bisphenol A) did not seem to have any effects on it. We demonstrated
that this method allows the direct detection of 17β-estradiol at concentrations above 1.4 μg/L (5 nM). 相似文献
87.
Boulinguiez B Le Cloirec P Wolbert D 《Langmuir : the ACS journal of surfaces and colloids》2008,24(13):6420-6424
The selection of a proper sorbent for a given application is a complex problem. The design and efficiency of adsorption processes require an equilibrium adsorption model. Linear transformation is one of the methods available to estimate the adjustable parameters of isotherm models but possesses limitations compared to nonlinear regressions. A different approach to calculate predicted equilibrium isotherm values leading to an alternative nonlinear regression is presented in this paper and compared with usual regression methods. Adsorption isotherm data of gaseous THT onto three activated carbon materials constitute an experimental basis for the discussion. Assessment of the goodness-of-fit of the Langmuir model is supported by different selected test functions. The new nonlinear approach did not obtain the best results for each test function, but raises questions about the inherent combined error in regression procedures. 相似文献
88.
89.
90.
Echard JP Benoit C Peris-Vicente J Malecki V Gimeno-Adelantado JV Vaiedelich S 《Analytica chimica acta》2007,584(1):172-180
The organic constituents of historical vanishes from two ancient Italian lutes and a Stradivari violin, kept in the Musée de la musique in Paris, have been characterized using gas chromatography-mass spectrometry. Results have been compared with the chromatograms and mass spectra of recent as well as old naturally aged reference materials. The three historical varnishes analyzed have been shown to be oil varnishes, probably mixtures of linseed oil with resins. Identification of diterpenoids and triterpenoids compounds, and of the resins that may have been ingredients of the varnishes, are discussed in this paper. 相似文献