全文获取类型
收费全文 | 1029篇 |
免费 | 0篇 |
专业分类
化学 | 408篇 |
晶体学 | 28篇 |
力学 | 42篇 |
数学 | 210篇 |
物理学 | 341篇 |
出版年
2021年 | 12篇 |
2020年 | 16篇 |
2019年 | 19篇 |
2018年 | 35篇 |
2017年 | 26篇 |
2016年 | 30篇 |
2015年 | 11篇 |
2014年 | 26篇 |
2013年 | 37篇 |
2012年 | 33篇 |
2011年 | 48篇 |
2010年 | 37篇 |
2009年 | 37篇 |
2008年 | 37篇 |
2007年 | 36篇 |
2006年 | 38篇 |
2005年 | 31篇 |
2004年 | 19篇 |
2003年 | 26篇 |
2002年 | 18篇 |
2001年 | 31篇 |
2000年 | 22篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 14篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1991年 | 10篇 |
1990年 | 17篇 |
1989年 | 16篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 16篇 |
1982年 | 13篇 |
1981年 | 7篇 |
1980年 | 17篇 |
1979年 | 18篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 21篇 |
1975年 | 13篇 |
1974年 | 11篇 |
1973年 | 9篇 |
1970年 | 10篇 |
1969年 | 7篇 |
1968年 | 10篇 |
排序方式: 共有1029条查询结果,搜索用时 31 毫秒
11.
Kryazhimskiy A. V. Maksimov V. I. 《Proceedings of the Steklov Institute of Mathematics》2006,253(1):S168-S184
A problem of guaranteeing control for a system of parabolic equations is considered. A solving algorithm based on the combination of real time reconstruction processes and feedback control is designed. 相似文献
12.
A. A. Karabutov V. A. Larichev G. A. Maksimov I. M. Pelivanov N. B. Podymova 《Acoustical Physics》2006,52(5):582-588
The first experimental observation of the propagation dynamics of a short broadband acoustic pulse in a resonance medium with gas bubbles is carried out. The probing pulse is generated using the optoacoustic effect. It is shown that the theory of short pulse propagation in media with generalized resonance relaxation adequately and accurately describes the dynamics of short pulse dispersion. A possibility to determine the relaxation and resonance parameters of media by the pulsed testing technique is demonstrated. 相似文献
13.
14.
Maksimov R. D. Zicans J. Ivanova T. Negreeva S. N. Plume E. 《Mechanics of Composite Materials》2002,38(2):141-148
The results of experimental and theoretical investigations of elastic and thermophysical properties of poly(vinyl chloride) (PVC) and chlorinated polyethylene (CPE) blends are presented. Eight types of specimens with different ratios of weight contents of PVC and CPE (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) were tested. The effect of blend composition on the elastic constants (tensile and shear modulus) is discussed. The data on the thermal conductivity, thermal diffusivity, and heat capacity of the blends investigated are also presented. 相似文献
15.
Physical Engineering Institute, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 5, pp. 565–574, May, 1991. 相似文献
16.
O. Maksimov P. Fisher M. Skowronski P.A. Salvador M. Snyder J. Xu X. Weng 《Journal of Crystal Growth》2008,310(11):2760-2766
MgO films were grown on (0 0 1) yttria-stabilized zirconia (YSZ) substrates by molecular beam epitaxy (MBE). The crystalline structures of these films were investigated using X-ray diffraction and transmission electron microscopy. Growth temperature was varied from 350 to 550 °C, with crystalline quality being improved at higher temperatures. The MgO films had a domain structure: (1 1 1)[1 1 2¯]MgO(0 0 1)[1 0 0]YSZ with four twin variants related by a 90° in-plane rotation about the [1 1 1]MgO axis. The observed epitaxial orientation was compared to previous reports of films grown by pulsed laser deposition and sputtering and explained as resulting in the lowest interface energy. 相似文献
17.
Dimeric stilbenes have been isolated from the wood of Amur maackia for the first time. Two of them have been identified as the known scirpusins A and B. The structure of a new dimeric stilbene with a dioxane linkage, which has been called maackinin, has been established. The PMR and13C NMR spectra of the substances isolated have been studied in detail.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 468–476, September–October, 1992. 相似文献
18.
19.
Suzdalev I. P. Buravtsev V. N. Maksimov Yu. V. Zharov A. A. Imshennik V. K. Novichikhin S. V. Matveev V. V. 《Russian Chemical Bulletin》2003,52(9):1950-1958
Magnetic phase transitions of the first and second order were revealed by Mössbauer spectroscopy in nanosystems of - and -ferric oxides and metallic europium subjected to shear stress (240°) under high pressure (20 kbar). For - and -ferric oxide nanoclusters, the Curie (Neel) points decreased to 300 K, whereas for nanostructured europium the Neel point increased from 90 to 100 K. The thermodynamic model of magnetic phase transitions predicting a change in the character of magnetic phase transitions and a decrease (increase) in the critical Neel (Curie) points in nanoclusters was developed. The type of magnetic phase transitions and the change in the critical points were caused by defects in nanoclusters, whose maximum concentration was observed for the clusters with the 20—50 nm size range. 相似文献
20.
G. M. Maksimov G. S. Litvak A. A. Budneva E. A. Paukshtis A. N. Salanov V. A. Likholobov 《Kinetics and Catalysis》2006,47(4):564-571
Thirty (5–40)% WO3/MO2 (M = Zr, Ti, Sn), heterogeneous acidic catalysts have been synthesized by two methods, specifically, via homogeneous acid solutions and from solutions brought to pH 9 with ammonia, both followed by calcination at 600–900°C. The catalysts have been characterized by IR spectroscopy and scanning electron microscopy, and their aqueous washings have been analyzed. Their acidity has been determined by the thermal analysis of samples containing adsorbed pyridine, and in terms of the proton affinity scale. Catalytic activities have been compared for cumene hydroperoxide (CHP) decomposition at 40°C in cumene and acetone. For all M, the catalysts are one type and contain W in strongly and weakly bound states, the latter being a polyoxometalate that can be washed off. Both tungstate phases are active in acid catalysis. Brønsted acid sites with a broad strength distribution have been found. The strongest of them are heteropolyacid protons. The catalysts 30% WO3/SnO2 and 20% WO3/ZrO2 (in acetone) and 10–20% WO3/TiO2 (in cumene) are the most active in CHP decomposition, and their activity is not related to their total acidity. Phases containing W6+ that form during the high-temperature synthesis are responsible for the high acidity, and additional protons that may appear owing to W6+ reduction can play only a minor role. 相似文献