全文获取类型
收费全文 | 712篇 |
免费 | 7篇 |
专业分类
化学 | 378篇 |
晶体学 | 10篇 |
力学 | 7篇 |
数学 | 81篇 |
物理学 | 243篇 |
出版年
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2014年 | 13篇 |
2013年 | 33篇 |
2012年 | 27篇 |
2011年 | 23篇 |
2010年 | 16篇 |
2009年 | 15篇 |
2008年 | 27篇 |
2007年 | 25篇 |
2006年 | 24篇 |
2005年 | 28篇 |
2004年 | 24篇 |
2003年 | 18篇 |
2002年 | 12篇 |
2001年 | 15篇 |
2000年 | 19篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 15篇 |
1996年 | 12篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 29篇 |
1992年 | 21篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 15篇 |
1987年 | 6篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 13篇 |
1973年 | 13篇 |
1972年 | 5篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1897年 | 4篇 |
排序方式: 共有719条查询结果,搜索用时 31 毫秒
81.
82.
83.
A method is described to determine Atrazine and its cross-reacting relatives in water, using a previously described graphite based one-way immunoelectrode and any standard millivoltmeter with low input bias current. The new procedure separates the potential measuring step from the incubation step. In this way, the conditions for highly stable potential measurements and for a most effective formation of the hapten (Atrazine) antibody complex can be optimized separately and all imponderable influence from ions in the analyte water is excluded. The limit of detection of such an electrode is some nanogram per liter.Part III: see [4] 相似文献
84.
85.
J.E. House Jr. G.L. Jeyaraj David A. Engel Michael D. Lowery 《Thermochimica Acta》1983,70(1-3):189-193
The decomposition of Li2S2O6·2 H2O, Na2S2O6·2 H2O, and MgS2O6·7 H2O has been studied using TG and DTG. Both sodium and lithium dithionates dehydrate in one step. Magnesium dithionate dehydrates in three separate steps. All three of the dithionates undergo further decomposition and lose sulfur dioxide to give stable sulfates. Kinetic parameters are presented for these reactions. 相似文献
86.
T. Tschudi G. Herziger A. Engel 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1973,24(3):449-449
Ohne Zusammenfassung 相似文献
87.
Oligopeptides with the sequence Z(GlyProPro)nOBut (n = 3–7) were synthesized along a clasical pathway. Generally long fragments were condensed in order to allow an easy separation of the products from the reactants. It is established by molecular weight determination and measurements of circular dichroism that the peptides form the collagen-like triple helix in methanol and that they assume the random coil conformation in dilute acetic acid. The circular dichroism spectra agree reasonably well with the corresponding spectra for (ProProGly)10 which was obtained by solid phase synthesis in another laboratory. 相似文献
88.
A. Von Engel 《Applied Scientific Research》1956,5(1):34-42
Summary A short survey is given of the work of measuring and analyzing the radiation in the far u.v. which originates in the gas of an electric discharge. A new method is briefly described including some preliminary results. 相似文献
89.
Mylan Engel 《Acta Analytica》2005,20(2):56-79
The paper takes as its starting point the observation that people can be led to retract knowledge claims when presented with
previously ignored error possibilities, but offers a noncontextualist explanation of the data. Fallibilist epistemologies
are committed to the existence of two kinds of Kp-falsifying contingencies: (i) Non-Ignorable contingencies [NI-contingencies] and (ii) Properly-Ignorable contingencies [PI-contingencies]. For S to know that p, S must be in an epistemic position to rule out all NI-contingencies, but she need not be able to rule out the PI-contingencies.
What is required vis-à-vis PI-contingencies is that they all be false. In mentioning PI-contingencies, an interlocutor can lead S mistakenly to think that these contingencies are NI-contingencies, when in fact they are not. Since S cannot rule out these newly mentioned contingencies and since she mistakenly takes them to be NI-contingencies, it is quite natural that she retract her earlier knowledge claim. In short, mentioning NI-contingencies creates a distortion
effect. It makes S think that the standards for knowledge are higher than they actually are, which in turn explains why she mistakenly thinks
she lacks knowledge. Conclusion: The primary linguistic data offered in support of contextualism can be explained without
resorting to contextualism. 相似文献
90.
Atom diffraction from surfaces has proved to be a very useful method for structural studies on surfaces, particularly for incommensurate layers and hydrogen adlayers which are not easily analyzed with LEED. We have developed a rapid method to obtain the surface corrugation function directly from the measured intensities within the hard wall model. This avoids a tedious search in parameter space to determine surface structures and is valid for surfaces whose corrugation amplitudes are below the Rayleigh limit. We will discuss the method and its sensitivity to experimental errors in determining the diffraction intensities as well as its applicability when only a fraction of the allowed diffraction beams are experimentally accessible. 相似文献