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741.
It is demonstrated that during cold plastic deformation of coarse-plate perlite in carbon steel, planar cementite defects play the key role in deformation transfer through interphase boundaries and promote dissolution of cementite plates. It is first established that the austenite substructure formed upon high-temperature deformation is inherited by cementite and ferrite components of perlite during the subsequent phase transformation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 18–27, August, 2004.  相似文献   
742.
Conjugate reduction of alkynones by stoichiometric [(Ph(3)P)CuH](6) or catalytic [(Ph(3)P)CuH](6) and polymethyl-hydrosiloxane proceeds to cyclization by an aldol reaction with tethered ketones to generate [small beta]-hydroxyenones with good diastereoselectivity.  相似文献   
743.
Coal is the most important nonrenewable energy source of fossil origin. It is also the most common fuel in thermal power plants. However, during coal incineration in power plants, high sulfur content of coal poses serious environmental problems owing to sulfur dioxide emission. We studied the application of microbial methods for removal of sulfur from three types of high sulfur coals—two samples collected from Assam and Rajasthan in India and one from Libiaz, Poland. These coal samples were desulfurized using indigenous Acidithiobacillus sp. After investigation of the effect of various parameters, the conditions optimized for the maximum removal of total sulfur (91.87% for lignite, 63.13% for Polish coal, and only 9.44% for Assam coal) were as follows: initial pH of 1.5 (2.5 in the case of Assam coal), particle size of 45 μ, pulp density of 2% (w/v), incubation period of 30 d at −35°C in presence of 44.2 g/L of ferrous sulfate in the media with shaking at 140 rpm. Poor removal of sulfur in the case of Assam coal was owing to extensive precipitation of jarosites. In addition, the sulfur in Assam coal is mostly found in organic form, which is difficult to remove with Acidithiobacillus sp. The removal of sulfur from the three coal samples was demonstrated with photomicrographic studies.  相似文献   
744.
We grow single and twofold stacked island layers on patterned substrates and investigate the material distribution in and around the patterned area. For both layers a pronounced material depletion region occurs outside the pattern. The material gradients across the planar-patterned interface are symmetric in the first, but highly asymmetric in the second layer. We can describe these phenomena by simulations that take into account the surface curvature for the first and a strain-field modulated surface for the second layer.  相似文献   
745.
In this article we attempt to bring out some significant general aspects of what we call collapse-induced quantum nonlocal effects resulting from the use of the hypothesis of wave function collapse.  相似文献   
746.
Electron mobility in compensated semiconductors for ionised impurity scattering is calculated. A simple screened dipole potential is used. The calculations differ from those of Stratton due to the fact that in this paper the mobility is exactly calculated.  相似文献   
747.
748.
In this paper some new kinds of generalized Logarithmic and Harmonic Convex functions have been introduced and their relationships with known concepts have been discussed.  相似文献   
749.
A simple synthesis of acenaphthoquinolines by thermal cyclization of anils is described.  相似文献   
750.
Andrographolide, the principal secondary metabolite of Andrographis paniculata, displays a wide spectrum of medicinal activities. The content of andrographolide varies significantly in the species collected from different geographical regions. Therefore, this study aims at investigating the role of different abiotic factors and selecting suitable sites for the cultivation of A. paniculata with high andrographolide content using a multilayer perceptron artificial neural network (MLP-ANN) approach. A total of 150 accessions of A. paniculata collected from different regions of Odisha and West Bengal in eastern India showed a variation in andrographolide content in the range of 0.28–5.45% on a dry weight basis. The MLP-ANN was trained using climatic factors and soil nutrients as the input layer and the andrographolide content as the output layer. The best topological ANN architecture, consisting of 14 input neurons, 12 hidden neurons, and 1 output neuron, could predict the andrographolide content with 90% accuracy. The developed ANN model showed good predictive performance with a correlation coefficient (R2) of 0.9716 and a root-mean-square error (RMSE) of 0.18. The global sensitivity analysis revealed nitrogen followed by phosphorus and potassium as the predominant input variables influencing the andrographolide content. The andrographolide content could be increased from 3.38% to 4.90% by optimizing these sensitive factors. The result showed that the ANN approach is reliable for the prediction of suitable sites for the optimum andrographolide yield in A. paniculata.  相似文献   
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