全文获取类型
收费全文 | 151篇 |
免费 | 4篇 |
国内免费 | 2篇 |
专业分类
化学 | 57篇 |
晶体学 | 2篇 |
力学 | 48篇 |
数学 | 13篇 |
物理学 | 37篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 10篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 46 毫秒
1.
V. S. Kirilyuk 《Journal of Mathematical Sciences》1995,77(6):3486-3488
We consider an elastic isotropic material containing a fibrous inclusion or a void subject to loads. We study the possibility
of increasing the strength of the material using “control action.” As examples of such actions we consider an additional external
load, application of pressure in the cavities (voids), and variation of the temperature of uniform heating of the medium with
the inclusions. Studies are carried out for two-dimensional problems of linear elasticity theory. From the class of all possible
actions we single out a subclass leading to states of equal strength along the phase interface. We study the efficiency of
these types of action and show that in certain cases they lead to a manifold increase in the strength of the material. We
give the results of numerical studies.
Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 24, 1993, pp. 15–19. 相似文献
2.
V. S. Kirilyuk 《Journal of Mathematical Sciences》1991,57(1):2861-2864
This article examines a problem of static thermoelasticity for an isotropic medium with an ellipsoidal cavity. The orientation of the cavity relative to the heat flow is assumed to be arbitrary. The solution of the problem is constructed in closed form and is expressed through incomplete elliptic integrals of the first and second kinds. In cases when the ellipsoid degenerates into a spheroid or sphere, the stress-strain state can be written in elementary functions of the ellipsoidal coordinate.Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 19, pp. 46–50, 1988. 相似文献
3.
Binyuan Liu Yang Li Boo‐Gyo Shin Do Yeung Yoon IL Kim Li Zhang Weidong Yan 《Journal of polymer science. Part A, Polymer chemistry》2007,45(15):3391-3399
Three novel functionalized polynorbornenes (PNB) with pendant dimethyl carboxylate group (carboxylates—acetate, propionate, and butyrate) are synthesized as a vinyl‐type with a palladium (II) catalyst in high yield. The effects of size of substitutents, molar ratio of monomer to catalyst, solvent polarity, reaction time, and temperature on the polymerization of exo‐norbornene dimethyl propionate were systematically investigated. The low molar ratio and temperature, as well as high polarity of solvent, and long reaction time, are favorable for the enhancement of the monomer conversion, especially, the solvent have an obvious effect on the catalyst activity. The resulting poly(cis‐norbornene‐exo‐2,3‐dimethyl carboxylates) (PNB‐dimethyl carboxylates) show good solubility in common organic solvent and high thermal stability up to 360 °C. The glass transition temperature was detected by DMA at 331, 324, and 318 °C for acetate, propionate, and butyrate, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3391–3399, 2007 相似文献
4.
Kirilyuk IA Bobko AA Khramtsov VV Grigor'ev IA 《Organic & biomolecular chemistry》2005,3(7):1269-1274
A series of 4-dialkylamino-2,5-dihydroimidazole nitroxides with pyridine-4-yl, 4-dimethylaminophenyl or 4-hydroxyphenyl groups in position 2 of the imidazole ring were prepared using the reaction of RMgBr with corresponding 5-dialkylamino-4,4-dimethyl-4H-imidazole 3-oxides. The EPR spectra of the nitroxides were shown to be pH-sensitive due to consecutive protonation of the amidino moiety and the basic group(s) at position 2 of the imidazole ring. The 5,5-dimethyl-4-(dimethylamino)-2-ethyl-2-pyridine-4-yl-2,5-dihydro-1H-imidazol-1-oxyl showed a monotonic increase in the isotropic nitrogen hyperfine (hfi) coupling constant alpha(N) of 1 .4 G over a pH range from 2 to 6.5. Such a broad range of pH-sensitivity could be useful for many biophysical and biomedical applications, including pH-monitoring in the stomach. 相似文献
5.
The reactions of cyclic aldo- and -methoxynitrones of the 2H-imidazole-1-oxide and 4H-imidazole 3-oxide series with isocyanates, phenyl isothiocyanate, N-phenylmaleimide, and dimethyl acetylenedicarboxylate were studied. The reactions give the corresponding 1,3-dipolar cycloaddition products. 2,2-Dimethyl-4-phenyl-2H-imidazole 1-oxide does not enter into a similar reaction with isocyanates or phenyl isothiocyanate. 相似文献
6.
MODELING HARVEST SCHEDULING IN MULTIFUNCTIONAL PLANNING OF FORESTS FOR LONGTERM WATER YIELD OPTIMIZATION
下载免费PDF全文
![点击此处可从《Natural Resource Modeling》网站下载免费的PDF全文](/ch/ext_images/free.gif)
HAYATI ZENGIN ÜNAL ASAN SINAN DESTAN MURAT ENGIN ÜNAL AHMET YEŞIL PETE BETTINGER AHMET SALIH DEĞERMENCI 《Natural Resource Modeling》2015,28(1):59-85
In this study, wood production and hydrologic functions of forests were accommodated within a planning procedure for separate working circles (areas dedicated to certain forest functions) that were delineated according to an Ecosystem‐Based Functional Planning approach. Mixed integer goal programming was used as the optimization technique. The timing and scheduling of a maintenance cutting (partial harvest) was the decision variable in the modeling effort, and an original formulation was developed as a multiobjective planning procedure. Four sample planning strategies were developed and model outputs were evaluated according to these strategies. Spatial characteristics of stands were considered, and used to prohibit the regeneration of adjacent stands during the same time period. Because of the positive relationship between qualified water production and standing timber volume in the forest, the model attempts to maximize qualified water production levels by increasing standing volume stocks in the forest through the delay of regeneration activities. 相似文献
7.
P. A. Usachev R. V. Pisarev A. M. Balbashov A. V. Kimel A. Kirilyuk Th. Rasing 《Physics of the Solid State》2005,47(12):2292-2298
Optical properties of the orthorhombic thulium orthoferrite TmFeO3 were studied in the spectral range from 0.64 to 5.4 eV. In the weak absorption region, below 2.2 eV, the energies of localized optical transitions in the Tm3+ and Fe3+ ions were determined. The dispersion relations of the real and imaginary parts of the principal refractive indices along three crystallographic axes were found. In the region of strong absorption, above 2.2 eV, the energies of six charge-transfer transitions were determined. The experimental data fit well to the concept of charge-transfer transitions in the FeO 6 9? octahedral complexes providing a dominant contribution to the optical properties of the orthoferrites. Optical birefringence and its temperature dependence were measured for the three principal directions of light propagation, and the anisotropic magnetic contribution to birefringence in the region of spin-orientational transitions was isolated. 相似文献
8.
Kimel AV Astakhov GV Schott GM Kirilyuk A Yakovlev DR Karczewski G Ossau W Schmidt G Molenkamp LW Rasing T 《Physical review letters》2004,92(23):237203
Static and time-resolved magneto-optical spectra of the ferromagnetic semiconductor (Ga,Mn)As show that a pulsed photoexcitation with a fluence of 10 microJ/cm(2) is equivalent to the application of an external magnetic field of about 1 mT, which relaxes with a decay time of 30 ps. This relaxation is attributed to the spin relaxation of electrons in the conduction band and is found to be not affected by interactions with Mn ions. 相似文献
9.
Mariya V. Edeleva Igor A. Kirilyuk Dmitry P. Zubenko Irina F. Zhurko Sylvain R. A. Marque Didier Gigmes Yohann Guillaneuf Elena G. Bagryanskaya 《Journal of polymer science. Part A, Polymer chemistry》2009,47(23):6579-6595
The H‐atom transfer reaction was studied for a series of imidazoline, imidazolidine, and pyrrolidine‐based alkoxyamines containing either isobutyrate‐2‐yl or 1‐phenylethyl alkyl fragments. The C O bond homolysis rate constants and activation energies were determined by 1H NMR product analysis as a function of temperature. Inter‐ and intramolecular H‐atom transfer reactions were distinguished by examination of alkoxyamine thermolysis products in the absence and in the presence of a radical scavenger (thiophenol or deuterated styrene). A correlation between the structure of the nitroxyl fragment of alkoxyamine and the H‐transfer reaction was found. The high steric demands of the substituents on the nitroxyl part of the isobutyrate‐2‐yl alkoxyamine decrease both types of reaction. For alkoxyamines containing the 1‐phenylethoxyamines, neither inter‐ nor intramolecular H‐atom transfer was observed. Controlled polymerization of methylmethacrylate initiated with imidazoline‐based alkoxyamine was observed, although the polymer obtained was not living. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6579–6595, 2009 相似文献
10.
We examine the properties of the stressed state of the thin intermediate zone separating a nonhomogeneous inclusion from the matrix. Explicit expressions are given for the components of the stress tensor in the thin coating depending on the properties of the phases and the load parameters.Simferopol' University. Translated from Dinamicheskie Sistemy, No. 10, pp. 26–30, 1992. 相似文献