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11.
The Riccati type equation, the Biicklund transformation and the Lax pair of the Liouville equation are obtained by using the prolongation theory. It is shown that the prolongation structures generate the SL(2,R) Lie algebra. 相似文献
12.
制备一系列锗酸锌锰荧光体,并探讨其发光特性、瞬态荧光衰减与色度值与所掺杂锰离子含量之间的相互关系.本系列荧光体锰离子发射峰波长,随Mn2+含量由0增加0.05,由527nm红移至534nm.实验表明这可能与Mn2+所占据的四面体格位,遭扭曲而导致晶场强度变弱有关.本系列荧光体的CIE色度坐标值,则随所掺杂Mn2+含量,仅有微小改变.锗酸锌锰荧光体瞬态荧光衰减的研究结果表明:锗酸锌基质的衰减生命期在纳秒范围;随Mn2+掺杂量增加,在毫秒范围的锰离子荧光衰减生命期逐渐缩短.此现象可能与Mn2+-Mn2+离子对中,Mn2+的自旋交换相互作用有密切关系. 相似文献
13.
评述了天体物理中暗物质的发现以及标准模型所面临的问题,综述了解决这些问题及标准模型之外可能出现的新物理与暗物质的联系。介绍了暗物质粒子选择条件和可能的暗物质粒子的候选者;对圆柱形暗物质表面密度与星系和星系团暗物质晕的晕核半径的关系进行了讨论,与其他模型进行了比较,得出暗物质晕的特征半径r*的暗物质表面密度分布不是一个普适量;并叙述了近几年暗物质研究中提出的新理论模型-Hidden dark matter,最后叙述了中国暗物质实验探测研究的进展,2016年底DAMPE的第一批数据有可能给出;中国锦屏地下实验室(CJPL)的CDEX和PandaX合作组的第一期实验没有发现暗物质粒子存在的信号,期待他们下期的实验。A review of the evidence of the dark matter found in universe and the problems faced by the standard model. To address these issues as well as the possible relationship between the new physics beyond the standard model and dark matter, and given the selection condition of dark matter and possible candidates of the weakly-interacting massive particles (WIMPs). The correlation between the column surface density and the halo core radius of the dark matter halos of galaxies and cluster of galaxies is discussed, and the other models are compared. We find that the surface density within the halo characteristic radius r* is not an universal quantity; The new model (hidden dark matter)proposed in the study of dark matter is described. At last, the research progress of dark matter experiment in China is commented. At the end of 2016, the first batch of DAMPE data may be given;No significant excess events of WIMPS were found in the first stage of both the CDEX and PandaX experiments located in the China Jinping Underground Laboratory(CJPL). Look forward to their the next stage of these experiments in CJPL. 相似文献
14.
PreliminaryStudyonDestructionofFreon12byInductivelyCoupledPlasma——DevelopmentofICPTechnologyforWasteDestructionCHENDeng-yunan... 相似文献
15.
Sukkum Ngullie CHANG Jeong Jun LEE Hyun Jin KIM Sun Chul KANG 《Turkish Journal of Chemistry》2021,45(4):1155
Vitamin D2 (vit. D2) is a nutraceutical essentially needed for good health. However, it is susceptible to oxygen and high temperature. The use of natural products such as bioflavonoids possessing anti-degradative effect of vit. D2 degradation has not been described before. A combinational effect of vit. D2 with quercetin showed a positive effect and inhibited vit. D2 degradation when exposed to high temperature (50 ℃ and 75 ℃) at different time points. The results obtained revealed vit. D2 degradation was drastically increased with longer incubation under thermal treatment. However, quercetin and vit. D2 groups were able to significantly inhibit the degradation of vit. D2 and stabilize it, evaluated through the retention percentage. We also exposed vit. D2 at solutions with different pH values (1, 4, 5, 7, 10). Quercetin exerted vit. D2 anti-degradation at different pH values as well as under thermal pressure at different time points. Conclusively, quercetin can be an effective way to reduce temperature and pH induced degradation of vit. D2. 相似文献
16.
LEE H. PrattYukio SMMAZAKIT†Yasunori Inoue†Masaki Furuya† 《Photochemistry and photobiology》1982,36(4):471-477
Phototransformation of the red-absorbing form of phytochrome (Pr) to the far-red-absorbing form (Pfr) was followed with a custom-built transient spectrum analyzer. Large phytochrome, which consisted of approximately 120000-dalton monomers, was immunopurified or conventionally purified from etiolated oat (Avena sativa L., cv. Garry) shoots. Phototransformation was initiated by exciting Pr with a 115-mJ, 600-ns half-width, 655-nm laser pulse. Absorption spectra were recorded on a microsecond time scale at predetermined times after the flash. It has been reported earlier that flash excitation of large oat Pr produces a transformation intermediate with maximum absorbance near 700 nm in a difference spectrum and that this intermediate decays by two kinetically distinct reactions. Difference spectra for these two reactions are indistinguishable. Both show bleaching centered at 690 nm with no detectable associated absorbance increase between 570 and 830 nm. Subsequent appearance of absorbance at 724 nm, which presumably but not necessarily represents the appearance of Pfr, had earlier been shown to occur by two kinetically distinct reactions for large oat phytochrome. Data presented here indicate in addition the occurrence of a third, slower reaction. Difference spectra for the two faster reactions are indistinguishable, both with maxima near 728 nm and minima near 650 nm. The difference spectrum for the slowest component, however, was qualitatively different exhibiting a maximum near 722 nm with no corresponding minimum. About 15-20% of the absorbance increase at 724 nm occurred by this slowest reaction, which exhibited a half-life of 3 s at 25°C and a Q10 of 1.2 for immunopurified and 1.5 for conventionally purified phytochrome. The percentage occurring by this reaction was independent of temperature over the range studied (1-25dEC). For immunopurified phytochrome the enthalpy of activation, Gibbs free energy of activation, and entropy of activation of this slowest reaction were found to be about lOkJ-mol-1, 75kJ.mol-1, and -220 J.mol-1 K-1, respectively, and for conventionally purified phytochrome 25kJ.mol-1, 75kJ.mol-1and —170 J.mol-1 K-1, respectively. The thermodynamic characteristics of this reaction indicate that it may involve a significant ordering of the protein moiety as it transforms to Pfr. 相似文献
17.
Circular-polarization discrimination appears in many antennas' applications. A compensation approach based on multilayer film structure is proposed to improve the axial ratio of the magnitude of the two perpendicular modes of the lump ports. The goal is to widen the beamwidth of radiation that has an axial ratio less than 3 dB and thus reducing the complexity at the receiver. A transfer matrix method was developed to represent the multilayer film and characterize its performance. Simulation using high frequency structure simulator shows that a crossed dipole, as an example, can achieve a beamwidth of more than at the frequency of 12.45 GHz after compensation. Finally, conclusions and future work about this compensation method are presented. 相似文献
18.
19.
This paper presents an investigation into the dynamic stability of skew plates acted upon simultaneously by an aerodynamic force in the chordwise direction and a random in-plane force in the spanwise direction. Due to this random in-plane force, the plate may become unstable before the aerodynamic force reaches its critical value. In this work, the finite element formulation is applied to obtain the discretized system equations. The system equations are then partially uncoupled and reduced in size by the modal truncation method. Finally, the unsmoothed and the smoothed versions of the stochastic averaging are used to calculate the system response, and the second-moment stability criterion is utilized to determine the stability boundary of the system. Numerical results show that the stability boundary obtained by the smoothed stochastic averaging is less conservative than that obtained by the unsmoothed version, and the former is the tangent of the latter at zero spectral density of the random in-plane force. 相似文献
20.