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971.
972.
Multi-reference configuration interaction is used to produce potential energy curves(PECs) for the excited B1Π state of KH molecule.To investigate the correlation effect of core-valence electrons,five schemes are employed which include the different correlated electrons and different active spaces.The PECs are fitted into analytical potential energy functions(APEFs).The spectroscopic parameters,ro-vibrational levels,and transition frequencies are determined based on the APEFs and compared with available experimental and theoretical data.The molecular properties for B1Π obtained in this letter,which are better than those available in literature,can be reproduced with calculations using the suitable correlated electrons and active space of orbitals.  相似文献   
973.
A theory is developed for the self-phase compensated optical waveguide isolator recently reported in the literature. The operation principle of such device is explained in terms of synchronization of phase and power conversion. The effect of balancing phase mismatches of the two convertors on achieving a proper percentage of mode conversion is revealed. The way to make use of the phase mismatches of different sections to accommodate the different requirements in phase relationship for the reciprocal and nonreciprocal mode convertors is discussed. The theory is extended to the case where phase compensator is used. It is demonstrated that the introduction of phase compensator separates the adjustment of phase from the adjustment of power for the mode convertors so that relaxes fabrication tolerances of such devices. An isolator consists of three phase mismatched waveguide sections is designed and simulated. The simulation results confirm the self-phase compensation theory.  相似文献   
974.
Thermoluminescent dosimeters are widely applied in the measurement of radiation dose. Since the luminescent centers are not lost during the reading process, radiophotoluminescent glass dosimeters (RPLGDs) can be repeatedly readout. The aims of this study were to make RPLGD and to analyze its physical and chemical properties. This study used chemical compounds such as Na3PO4, AlPO4, AgCl, AgNO3, B2O3, H3PO4 and P2O5 as the main ingredients. Depending on the self-fabricated glass compounds, the melting temperatures were between 1100 and 1500 °C. When the 0.1 mol% of silver was added, the radiation detection of self-fabricated RPLGD reached to the highest sensitivity. However, when silver concentration was larger than 0.1 mol%, the radiation detection sensitivity plummets rapidly. Excess amounts of silver and aluminum decreased the penetrate capability of ultraviolet spectrum. Based on our study, we found that chemical compound concentrations and melting process, which all affect radiation sensitivity and stability of self-fabricated RPLGD.  相似文献   
975.
The development of dependable, environmentally benign processes for the synthesis of nanoscale materials is an important aspect of nanotechnology. In the present study, we report one-pot biogenic fabrication of palladium nanoparticles by a simple procedure using broth of Cinnamomum camphora leaf without extra surfactant, capping agent, and/or template. The mean size of palladium nanoparticles, ranging from 3.2 to 6.0 nm, could be facilely controlled by merely varying the initial concentration of the palladium ions. The polyols components and the heterocyclic components were believed to be responsible for the reduction of palladium ions and the stabilization of palladium nanoparticles, respectively.  相似文献   
976.

Abstract  

This article describes a facile green strategy for preparing the Ni(OH)2 microsphere assembled by nanoribbons by the template of the squama inner coat of onion at mild condition. The method is simple and effective. The results of SEM show the products are Ni(OH)2 microspheres with diameters in the range of 500–2,500 nm. The results of TEM show the microsphere is assembly by nanoribbons, with thickness in the range of 30–50 nm. The products were characterized by powder X-ray diffraction, IR, and thermogravimetric analysis. A possible formation mechanism was also proposed.  相似文献   
977.
In order to investigate the correlations of morphologies and optical properties, different morphologies of Eu-doped ZnO were synthesized by different methods. Specifically, the structure of SiO2/ZnO:Eu nanoflower was synthesized for the first time and has not been reported previously. One percent was chosen as the Eu doping concentration. The relations of the morphology, diameter, and uniformity with the PL intensity were examined. The PL intensity of ZOE samples has a close relationship with the morphology. The PL intensity order of the different morphologies of ZnO:Eu is as follows: nanorod arrays > thin film > nanospheres > nanoparticles > nanoflowers > nanorods. The PL intensity of nanomaterials is larger, if the diameter of the nanomaterials is larger. However, the size of diameter is not the most important reason. It was found that the sample uniformity plays a key role on ZnO:Eu PL intensity. ZnO:Eu with small particle diameters may have strong photoluminescence intensity, if the nanoparticles are uniform.  相似文献   
978.
为实现高精度中小口径非球面的加工,介绍了一种非球面修抛技术。基于Preston假设,将抛光过程描述成一个线性方程,计算得到材料的去除量与抛光时间、抛光压力和零件转速之间的函数关系。设计了整体修抛法和环带修抛法两种方法,在数控抛光的基础上,对口径为Ф117mm的凹抛物面和口径为Ф17mm凸双曲面进行修抛,修抛后非球面的面形精度PV值为0.184μm,RMS均小于0.032μm,达到了工程化应用要求,实现了中小口径非球面的高精度加工。  相似文献   
979.
We investigate the injection of a pure spin current into a non-magnetic Cu wire in a lateral spin valve. We detect the spin accumulation occurring at the interfaces between the magnetic nanopillars and the non-magnetic wire in the non-local geometry. We confirm that the accumulated spins diffuse equally in the Cu wire irrespective of the presence of a charge current. The inversion of the injector and detector magnetic nanopillars does not affect the spin signal, in agreement with analytical predictions for this system.  相似文献   
980.
In this paper, we investigate the positive solutions of a second-order system with impulse effects. By using critical point theory the existence result of positive solutions is obtained.  相似文献   
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