全文获取类型
收费全文 | 127篇 |
免费 | 0篇 |
专业分类
化学 | 56篇 |
晶体学 | 2篇 |
数学 | 9篇 |
物理学 | 60篇 |
出版年
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2013年 | 7篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1956年 | 1篇 |
1942年 | 2篇 |
1939年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有127条查询结果,搜索用时 15 毫秒
61.
AP Balachandran 《Pramana》2002,59(2):359-368
We review certain emergent notions on the nature of space-time from noncommutative geometry and their radical implications.
These ideas of space-time are suggested from developments in fuzzy physics, string theory, and deformation quantization. The
review focuses on the ideas coming from fuzzy physics. We find models of quantum space-time like fuzzy S
4 on which states cannot be localized, but which fluctuate into other manifolds like CP3. New uncertainty principles concerning such lack of localizability on quantum space-times are formulated. Such investigations
show the possibility of formulating and answering questions like the probability of finding a point of a quantum manifold
in a state localized on another one. Additional striking possibilities indicated by these developments is the (generic) failure
of CPT theorem and the conventional spin-statistics connection. They even suggest that Planck’s ‘constant’ may not be a constant,
but an operator which does not commute with all observables. All these novel possibilities arise within the rules of conventional
quantum physics, and with no serious input from gravity physics. 相似文献
62.
Gnanakumar ES Thushara KS Bhange DS Mathew R Ajithkumar TG Rajamohanan PR Bhaduri S Gopinath CS 《Dalton transactions (Cambridge, England : 2003)》2011,40(41):10936-10944
Benzyl alcohol has been used to prepare a single phase MgCl(2).6BzOH molecular adduct as a support for an ethylene polymerization catalyst (Ziegler catalyst). The structural, spectroscopic and morphological aspects of the MgCl(2).6BzOH molecular adduct and the Ziegler catalyst have been thoroughly studied by various physicochemical characterization techniques. The presence of MgO(6) octahedrons due to the interaction of Mg(2+) with six -OH groups of the benzyl alcohol is confirmed from a Raman feature at 703 cm(-1), and structural studies. The supported catalyst activity has been evaluated for the ethylene polymerization reaction. The lower polymerization activity of the titanated Ziegler-Natta catalyst compared with a standard catalyst is attributed to the strong interaction of titanium chloride with the support and associated electronic factors. 相似文献
63.
Methods for phase retrieval in digital speckle shearing interferometry (DSSI) with relatively large deformation are proposed using a single wavelength illumination with windowed Fourier filtering (WFF) and two-wavelength simultaneous illumination with iterative sine-cosine average filtering (ISCAF). For relatively large deformation measurement, WFF technique has a higher noise suppression capability than ISCAF technique but requires careful selection of the processing parameters, while ISCAF is a simple filtering with less parameter setting. Both methods for phase retrieval are discussed. Experimental results show that both methods are capable of noise suppression in the phase retrieval for relatively large deformation. 相似文献
64.
Anirban Bhaduri Susmita Bhaduri Dipak Ghosh 《Physics of Particles and Nuclei Letters》2017,14(4):576-583
Various works on multiplicity fluctuation have investigated the dynamics of particle production process and eventually have tried to reveal a signature of phase transition in ultra-relativistic nuclear collisions. Analysis of fluctuations of spatial patterns has been conducted in terms of conventional approach. However, analysis with fractal dynamics on the scaling behavior of the void has not been explored yet. In this work we have attempted to analyze pion fluctuation in terms of the scaling behavior of the void probability distribution in azimuthal space in ultra-relativistic nuclear collisions in the light of complex networks. A radically different and rigorous method viz. Visibility Graph was applied on the data of 32S-Ag/Br interaction at an incident energy of 200 GeV per nucleon. The analysis reveals strong scaling behavior of void probability distributions in azimuthal space and a strong centrality dependence. 相似文献
65.
A comparative study of phase-shifting algorithms in digital speckle pattern interferometry 总被引:1,自引:0,他引:1
Digital speckle pattern interferometry (DSPI) is a tool for making qualitative as well as quantitative measurements of deformation of objects. Phase-shifting algorithms in DSPI are useful for extracting quantitative deformation data from the system. Comparative studies of the different phase-shifting algorithms in DSPI for object deformation measurement are presented. Static and quasi-dynamic deformation of the object can be measured using these algorithms. Error compensating five-step phase-shifting method is used for the algorithms. 相似文献
66.
67.
In a Hartree-Fock or Hartree-Foek-Bogoliubov calculation of a deformed intrinsic state, one obtains a distribution of angular momentum states. Using an analogy from statistical mechanics, we obtain an expression for this distribution. The concept of an average temperature for the intrinsic state is introduced, which is directly related to the rotational energy content of the intrinsic state. The relationship of this temperature to microscopic particle-hole calculations is clarified. Assuming a rotational spectrum for the ground-state band of an axially symmetric doubly even nucleus, it is demonstrated that the deduced distribution of the angular momentum states gives rise to an overlap function of the intrinsic wave function which falls off, for small angles of rotation, as a Gaussian. Finally, the Yoccoz formula for the moment of inertia is derived using classical statistical mechanics, and semiclassical corrections to it are obtained. 相似文献
68.
Curvature measurement using three-aperture digital shearography and fast Fourier transform 总被引:1,自引:0,他引:1
Basanta Bhaduri M.P. Kothiyal N. Krishna Mohan 《Optics and Lasers in Engineering》2007,45(10):1001-1004
Curvature measurement using a three-aperture digital shearography (DS) system is reported in this paper. The outer apertures are covered with wedge plates for introducing shear. Four images by sequentially blocking the outer apertures are used for quantitative measurement. Fourier transform technique is used to determine two sheared slope phase maps from two images at a time representing initial and deformed states. Subtraction of these two-phase maps yields the curvature phase map. Experimental results are presented for a circular diaphragm clamped along the edges and loaded at the center. 相似文献
69.
Measurement of surface figure of plane optical surfaces with polarization phase-shifting Fizeau interferometer 总被引:1,自引:0,他引:1
A Fizeau interferometer based set up for measurement of surface forms of plane optical surfaces has been discussed. Phase shifting interferometry has been applied using polarization phase shifter. A linearly polarized (632.8 nm) He–Ne laser has been used as the source. Light reflected from the object and the reference/master surfaces are made circularly polarized in opposite senses by means of two properly oriented quarter wave retardation plates placed at appropriate positions, one inside and other outside the interference cavity of the interferometer, and phase shifts are introduced between the object and the reference/master waves by varying angular orientation of a polarizer/analyzer. Final result is made free from any residual wave-front aberrations introduced by the (intra-cavity) wave plate by subtracting phase values obtained by PSI technique between a high optical quality master surface and the reference surface from that obtained for the test object surface with respect to the same reference surface for each point of the interference field. Results are shown for a plane surface.Advantages of the technique presented are linearity and high accuracy in phase stepping, no perturbation of the interference cavity during the phase shifting and possibility of real time or dynamic interferometry. 相似文献
70.
Mahavir Prashad M. Seth A. P. Bhaduri Avijit Banerji 《Magnetic resonance in chemistry : MRC》1980,14(1):74-75
13C NMR of diastereoisomeric pairs of 2,3-diaryl-2-methylbutyronitriles revealed a difference in the chemical shift of the carbon atoms between the diastereoisomers and the observed shifts were greatly influenced by the presence of an ortho substituent in the 3-phenyl ring. 相似文献