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181.
Feng S.-W. Tsai C.-Y. Cheng Y.-C. Liao C.-C. Yang C.C. Lin Y.-S. Ma K.-J. Chyi J.-I. 《Optical and Quantum Electronics》2002,34(12):1213-1219
A side-bump feature in a photoluminescence (PL) spectrum of an InGaN compound was widely observed. With reasonable fitting to PL spectra with three Gaussian distributions, the temperature variations of the peak positions, integrated PL intensities, and peak widths of the main and first side peaks of three InGaN/GaN multiple quantum well samples with different nominal indium contents are shown and interpreted. The existence of the side peaks is attributed to phonon–replica transitions. The variations of the peak position separations and the decreasing trends of the first side peak widths beyond certain temperatures in those samples were explained with the requirement of phonon momentum condition for phonon–replica transitions. In the sample with 25% nominal indium content, the phonon–replica transition could become stronger than the direct transition of localized states. 相似文献
182.
利用莫尔条纹的准正弦特性的三维轮廓术 总被引:5,自引:0,他引:5
分析了两个矩形光栅迭合产生的莫尔条纹的光强分布特性,通过选择适当的光栅参数,可得到一个近似的正弦分划板,并把它用于三维面形测量中,实验结果表明,这种方法简单,易于自动处理,有广泛的实用价值。 相似文献
183.
Wieczorek-Ciurowa K. Gamrat K. Paryło M. Shirokov Ju. G. 《Journal of Thermal Analysis and Calorimetry》2002,70(1):165-172
The physical mixtures of hydroxocarbonates of Cu and Ni with aluminium were activated using a laboratory planetary mill. The
chemical reactions and alloy formations as the effects of grinding were followed by the phase analysis of solid products based
on the thermogravimetry and X-ray diffractometry. Experimental evidence indicates that the nature of reactions and products
of mechanical activation was dependent on the amount of aluminium and time of grinding.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
184.
相型同步启动时间的M/M/c排队系统 总被引:4,自引:0,他引:4
本文研究带有同步启动时间的M/M/c系统,其中启动时间是相型变量,给出了稳态和等待时间分布等结果。 相似文献
185.
Hans -Peter Deutsch 《Journal of statistical physics》1992,67(5-6):1039-1082
A complete outline is given for how to determine the critical properties of polymer mixtures with extrapolation methods similar to the Ferrenberg-Swendsen techniques recently devised for spin systems. By measuring not only averages but the whole distribution of the quantities of interest, it is possible to extrapolate the data obtained in only a few simulations nearT
c
over the entire critical region, thereby saving at least 90% of the computer time normally needed to locate susceptibility peaks or cumulant intersections and still getting more precise results. A complete picture of the critical properties of polymer mixtures in the thermodynamic limit is then obtained with finite-size scaling functions. Since the amount of information extracted from a simulation in this way is drastically increased as compared to conventional methods, the investigation of mixtures with long chains or built-in asymmetries is now possible. As an example, the critical points, exponents, and amplitudes of dense, symmetric polymer mixtures with chain lengths ranging fromN=16 up toN=256 are determined within the framework of the 3D bond fluctuation model using grand canonical simulation techniques. As an example for an asymmetry, the generalization of the method to asymmetric monomer potentials is briefly discussed. 相似文献
186.
187.
S. Sarkar A. D. Thakur C. V. Tomy G. Balakrishnan D. McK Paul S. Ramakrishnan A. K. Grover 《Pramana》2006,66(1):193-207
New experimental data are presented on the scan rate dependence of the magnetization hysteresis width ΔM(H) (∞ critical current densityJ
c(H)) in isothermalMH scans in a weakly pinned single crystal of Ca3Rh4Sn13, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE). We observe an interesting
modulation in the field dependence of a parameter which purports to measure the dynamical annealing of the disordered bundles
of vortices injected through the sample edges towards the destined equilibrium vortex state at a givenH. These data, in conjunction with the earlier observations made while studying the thermomagnetic history dependence inJ
c(H) in the tracing of the minor hysteresis loops, imply that the partially disordered state heals towards the more ordered state
between the peak field of the SMP anomaly and the onset field of the PE. The vortex phase diagram in the given crystal of
Ca3Rh4Sn13 has been updated in the context of the notion of the phase coexistence of the ordered and disordered regions between the
onset field of the SMP anomaly and the spinodal line located just prior to the irreversibility line. A multi-critical point
and a critical point in the (H,T) region of the Bragg glass phase have been marked in this phase diagram and the observed behavior is discussed in the light
of recent data on multi-critical point in the vortex phase diagram in a single crystal of Nb. 相似文献
188.
Yan Shun MA Qing Hua MENG Hong Yu SHI Yuan De LONG Tian Bao HUANG 《中国化学快报》2006,17(6):807-808
Dencichine (β-N-oxalyl-L-α, β-diaminopropionic acid, L-ODAP), a nonprotein amino acid, is a haemostatic agent present in important Chinese medicinal herbs such as Panax notoginseng, as well as other Panax species1. It was first isolated from the seeds … 相似文献
189.
T. N. Sokolova V. R. Kartashov I. V. Timofeev Yu. K. Grishin N. S. Zefirov 《Russian Chemical Bulletin》1994,43(3):461-465
The dependence of the regiochemistry of the mercuration of bornylene on the nature of the mercurating reagent and on the solvent has been found. The structures of the intermediate and transition state in these reactions have been proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 501–505, March, 1994. 相似文献
190.
S. S. Batsanov 《Russian Chemical Bulletin》1994,43(2):199-201
Experimental data are used to determine the atomic volumes and radii of the elements of subgroups IV–VIIA in the structures of metallic phases at high pressures. Metallic radii of nonmetals are compared with values based on Pauling and Goldschmidt calculations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 220–222, February, 1994. 相似文献