全文获取类型
收费全文 | 58篇 |
免费 | 1篇 |
专业分类
化学 | 20篇 |
数学 | 4篇 |
物理学 | 35篇 |
出版年
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 1篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 6篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1998年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有59条查询结果,搜索用时 0 毫秒
1.
N. F. Morozov Yu. K. Startsev Yu. V. Sud’enkov A. A. Suslikov G. A. Baranov A. A. Belyaev 《Technical Physics》2006,51(7):872-877
The radiation hardness and mechanical strength of single-and two-phase glasses are studied for the case when nanosecond laser pulses (λ= 1.06 μm, τ0.5 ≈ 12.5 ns) are focused inside the material. Laser interferometry is applied to measure the displacement of the free surface, find optical breakage thresholds, and carry out the fractographic analysis of damaged regions. It is shown that breakdown channels and damage regions develop in a nonlinear manner according to optical breakdown mechanisms, changing each other with an increase in the laser energy. The strength of the two-phase glass is found to be more than four times that of the single-phase glass, although their elastic properties differ insignificantly. Such a considerable difference in the hardness of these materials with chemically similar constitutents is attributed to the presence of the double-lattice nanometer-scale structure of the two-phase glass. 相似文献
2.
3.
Results from Super-Kamiokande-I’s entire 1496 live days of solar neutrino data are presented, including the absolute flux,
energy spectrum, zenith angle (day/night) and seasonal variation. The possibility of MSW and vacuum oscillations is discussed
in light of these results. Results from the first 1289 days of Super-K-I’s atmospheric neutrino analysis are also presented,
including the evidence for νμ →ν
τ oscillations, against νμ → νsterile oscillations, and the current limits on proton decay. Finally, results based on 56 × 1019 protons on target are given for the K2K long-baseline neutrino oscillation experiment. 相似文献
4.
Ram Parkash S. C. Ahluwalia S. C. Sud R. N. Sahni R. C. Paul 《Monatshefte für Chemie / Chemical Monthly》1981,112(6-7):707-711
Heats solution of someLewis acids and bases in acetic anhydride have been determined and the following order of their relative strengths is proposed: SbCl5>SO3>SnCl4>TiCl4>AsCl3 and piperidine>
n-butylamine>potassium acetate>sodium acetate -picoline>quinoline. Heats neutralization of theseLewis acids and bases in acetic anhydride suggest that the major enthalpy change in these neutralization reactions is due to the combination of a proton and the (CH2COOCOCH3)-ion, resulting in the formation of acetic anhydride.
Lösungs- und Neutralisationswärmen von Lewis-Säuren und-Basen in Essigsäureanhydrid
Zusammenfassung Es wurden die Lösungswärmen einigerLewis-Säuren in Essigsäureanhydrid bestimmt und folgende Reihung nach ihrer relativen Stärke vorgeschlagen: SbCl5>SO3>SnCl4>TiCl4>AsCl3 und Piperidin> n-Butylamin>KAc>NaAc-Picolin>Chinolin. Die Neutralisationswärmen dieserLewis-Säuren und-Basen legen nahe, daß der Hauptanteil daran auf die Reaktion eines Protons mit (CH2–COOCOCH3)-zurückzuführen ist.相似文献
5.
6.
A rapid turbidimetric procedure for the determination of sulphate in soils and plants has been developed with sorbitol as stabilizing agent. When used in a concentration of 20% in the final volume, the sorbitol regulates the size of the BaSO(4) particles formed and stabilizes them against sedimentation, growth and aggregation for long periods of time. The conditions of precipitation are not rigorous, as they are in similar procedures. Linearity of the calibration curve up to 50 ppm of sulphate and good reproducibility are special attributes of the procedure. 相似文献
7.
We report the results of our modified distorted wave Born approximation calculation of triple differential cross section in the coplanar symmetric single ionization of potassium atom. We have included correlation-polarization potential as a function of electron density parameter and also studied the effect of post-collision interaction. The present attempt significantly improves the agreement between theoretical and experimental results. 相似文献
8.
J. Csikai Zs. Lantos S. Sudár T. Chimoye T. Vilaithong N. Chirapatpimol 《Zeitschrift für Physik A Hadrons and Nuclei》1986,325(1):69-72
Cross sections for the reactions27Al(n, p)27Mg and28Si(n,p)28Al were measured by activation method between 13.40 and 14.83 MeV neutron energy. An accuracy of about 4% was achieved using the27Al(n, α)24Na reaction as a reference at 14.1 MeV where the relative excitation function has also been measured. Results obtained were compared to a recent compilation and that calculated by the Hauser-Feshbach model. Using the back-shifted level density formula and taking into account the contribution of the separated levels, the calculations were extended to the energy range from the threshold to 18 MeV. A structure was observed in the27Al(n, α)24Na reaction cross section curve around 14 MeV neutron energy. 相似文献
9.
Molar extinction coefficients of some carbohydrates viz. l-arabinose (C5H10O5), d-glucose (C6H12O6), d-mannose (C6H12O6), d-galactose (C6H12O6), d(-) fructose (C6H12O6) and maltose (C12H24O12) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by gamma ray transmission method in a
narrow beam good geometry set-up. These coefficients have been found to depend upon the photon energy following a 4-parameter
polynomial. These extinction coefficients for different sugars having the same molecular formula have same values varying
within experimental uncertainty. Within concentration ranges studied, Beer-Lambert law is obeyed very well. 相似文献
10.
Restructuring in metals due to elastoplastic deformation produced by submicrosecond impulsive shock loading is studied experimentally. Tests are performed on 0.3ZhR iron and N1 nickel specimens with various structures. Structure modifications after shock tests are studied with acoustooptic spectroscopy. The frequency dependences of the longitudinal acoustic velocity and attenuation coefficient make it possible to estimate both the characteristic scales of restructuring in relation to the initial structure and the sensitivity of the acoustooptic method to restructuring in various materials. 相似文献