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71.
Field equations in the presence of wet dark fluid distribution are obtained in general relativity with the aid of Einstein-Rosen cylindrically symmetric metric.  相似文献   
72.
In this study, the equation of motion of a single link flexible robotic arm with end mass, which is driven by a flexible shaft, is obtained by using Hamilton's principle. The physical system is considered as a continuous system. As a first step, the kinetic energy and the potential energy terms and the term for work done by the nonconservative forces are established. Applying Hamilton's principle the variations are calculated and the time integral is constructed. After a series of mathematical manipulations the coupled equations of motion of the physical system and the related boundary conditions are obtained. Numerical solutions of equations of motion are obtained and discussed for verification of the model used.  相似文献   
73.
Kidney stones obtained from six patients belonging to the stone belt region of India (Punjab) were analyzed for inorganic constituents using instrumental neutron activation analysis (INAA) and energy dispersive X-ray fluorescence (EDXRF) techniques. For INAA, samples were irradiated along with IAEA RM Soil 7 as reference standard in CIRUS reactor, BARC, Mumbai. Gamma activity of irradiated samples was measured using a 45% relative efficiency HPGe detector coupled to 8?k channel analyzer. EDXRF method was used for determination of concentration of Ca. The concentrations of ten elements namely Ca, Na, K, Mn, Co, Cr, Zn, Br, Sm and Cl, are reported and discussed.  相似文献   
74.
I prove that the solutions of the phase-field equations, on a subsequence, converge to a weak solution of the Mullins-Sekerka problem with kinetic undercooling. The method is based on energy estimates, a monotonicity formula, and the equipartition of the energy at each time. I also show that for almost all t, the limiting interface is (d – 1)-rectifiable with a square-integrable mean-curvature vector.Dedicated to Mort Gurtin on the occasion of his sixtieth birthday  相似文献   
75.
The field equations for perfect fluid coupled with massless scalar field are solved with two conditions p=ρ and R=AS n for Kantowski-Sachs space time in general theory of relativity. Various physical and geometrical properties of the model have also been discussed.  相似文献   
76.
The first total synthesis of the dimeric alkaloid pigment scytonemin is described. The key transformations in its synthesis from 3-indole acetic acid are a Heck carbocyclization and a Suzuki-Miyaura cross-coupling, orchestrated in a stereospecific tandem fashion, followed by a biosynthetically inspired oxidative dimerization. The tandem sequence generates a tetracyclic (E)-3-(arylidene)-3,4-dihydrocyclopenta[b]indol-2(1H)-one that is subsequently dimerized into the unique homodimeric core structure of scytonemin.  相似文献   
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