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61.
HAN Tao LU XiaoChun WANG Xue RAO YongNan ZOU DeCai YANG JianFei & WU YangYang National Time Service Center Xi'an China Key Laboratory of Precision Navigation Timing Technology Chinese Academy of Sciences Graduate University of the Chinese Academy of Sciences Beijing 《中国科学:物理学 力学 天文学(英文版)》2011,(6)
With the development of Global Navigation Satellite System (GNSS),the idea of GNSS interoperability is born and has become the focus of study in the field of satellite navigation.The popularity for GNSS to augment the interoperability with the existing ones necessitates the study of the assessment algorithm of this idea.In this paper,an assessment algorithm for interoperability comprehensive benefits based on the differential equation dynamical system is discussed.There are two important aspects in GNSS tha... 相似文献
62.
LI ShuXia SUN PuNan & XIAO DeHang College of Physical Science Technology Heilongjiang University Harbin China 《中国科学:物理学 力学 天文学(英文版)》2011,(5)
We examine two-pion Bose-Einstein correlations for partially coherent particle-emitting sources within quantum statistical formalism, where the sources are treated as classical currents with chaotic and coherent components. The two-pion correlation functions of the partially coherent sources contain a phase which is sensitive to the asymmetry of the source emission function. We investigate the influence of source opacity and expansion in high energy heavy ion collisions on the phase by Monte Carlo calculati... 相似文献
63.
LIU QingMing BAI ChunHua JIANG Li DAI WenXi & NIU Fang State Key Lab of Explosion Science Technology Beijing Institute of Technology Beijing China 《中国科学:物理学 力学 天文学(英文版)》2011,(3)
The deflagration-to-detonation transitions (DDTs) for clouds of spherical aluminum dust (SAD) mixed with air or epoxypropane mist (EPM) and air were investigated in a 29.6-m-long experimental tube of 199 mm in diameter. The clouds formed through the injection of SAD and SAD/liquid epoxypropane samples into the experimental tube. Explosions of the SAD/air mixture were initiated using a 7-m-long EPM/air cloud explosion ignited by a 40-J electric spark. Explosions in SAD/EPM/air clouds were initiated using a 1... 相似文献
64.
Chemical composition,hourly counts,and sizes of atmospheric carbonaceous particles were measured to investigate their mixing state on clear and hazy days.623,122 carbonaceous particles with sizes0.2-2.0 μm was analyzed using a single-particle aerosol mass spectrometer from 1st to 17 th January2013.Particle types included biomass/biofuel burning particles(biomass),element carbon(EC-dominant)particles that were also mixed with biomass/biofuel burning species(EC-biomass) or secondary species(EC-secondary),organic carbon(OC),internally mixed OC and EC(OCEC),ammonium-containing(ammonium) and sodium-containing(sodium) particles.On clear days the top ranked carbonaceous particle types were biomass(48.2%),EC-biomass(15.7%),OCEC(11.1%),and sodium(9.6%),while on hazy days they were biomass(37.3%),EC-biomass(17.6%),EC-secondary(16.6%),and sodium(12.7%).The fractions of EC-secondary,ammonium(10%),and sodium particle types were elevated on hazy days.Numbers of EC-secondary particles were more than four times those on clear days(4.1%).Thus,carbonaceous particles mixed with ammonium,nitrate and sulfate during aging and transport,enhancing their light extinction effects and hygroscopic growth under high relative humidity on hazy days,further reducing visibility.Our real-time single-particle data showed that changes to mixing state had a significant impact on light extinction during haze events in Nanjing. 相似文献
65.
Spin Polarization Properties of Na Doped Meridianal Tris(8-Hydroxyquinoline) Aluminum Studied by First Principles Calculations 下载免费PDF全文
We theoretically investigate the electronic structure and spin polarization properties of Na-doped meridianal tris(S-hydroxyquinoline) aluminum (Alq3) by first principles calculations. It is found that the spin density is distributed mainly in the Alq3 part in the Alq3:Na complex. Electron charge transfer takes place from the Na atom to the Alq3 molecule, which induces asymmetric changing of the molecule bond lengths, thus the spin density distribution becomes asymmetric. Spin polarization of the complex originates from the preferable filling of the spin-split nitrogen and carbon p-orbitals because of the different bond length changes of the Aiq3 molecule upon Na doping. 相似文献
66.
SURFACE MODIFICATION AND DISPERSION OF NANODIAMOND IN CLEAN OIL 总被引:1,自引:0,他引:1
YongweiZhu XiangyangXu BaichunWang ZhijingFeng 《中国颗粒学报》2004,2(3):132-134
The effect of different kinds of surfactants on the size distribution of nanodiamond particles in clean oil was studied.Results show that the dispersing stability of nanodiamond modified with surfactangts YS-1 and SB-18 simulta-neously is much better than those modified with either of them because of synergism of the surfactangts.And the particle size distribution in the system can be improved remarkably after the adoption of hyperdispersants such as SA-E and SA-F.Anchoring groups of those hyperdispersants can be bonded with the particle surface by chemical and/or hydrogen bonding and their soluble chains are well compatible with the dispersion media.As a result,the particles are uniformly distrbuted in the system owing to the steric stabilization.A very stable clean-oil based nanodiamond suspension with an average particle size of around 53.2 nm was prepared. 相似文献
67.
68.
材料的动态损伤和失效 总被引:34,自引:0,他引:34
本文对动载荷下材料内部损伤演化过程的研究进行了较为全面、系统的介绍和总结,并对现有的各种动态损伤模型(包括笔者所提出的模型)进行了必要的比较、讨论和评述。 相似文献
69.
板壳塑性屈曲中的佯谬及其研究进展 总被引:6,自引:0,他引:6
本文详细论述了板壳塑性屈曲中的佯谬及其研究进展。并对现有的各种观点作了分析讨论。 相似文献
70.
用数值模拟手段详细地研究了振动翼型和襟翼的绕流问题,数值模拟的出发方程为Euler和N-S方程,格式为Bcam-Warming格式的改进型。数值实验主要针对流场的二大特性进行的,即振动对激波的影响和振动对分离的抑制作用,结果表明:(1)随翼型或襟翼的振动激波强度和位置也相应地变化但这一变化滞后于攻角的变化;(2)振幅加大激波强度的变化和激波运动范围也加大;(3)振动频率越高对激波的影响反而较低频时要小;(4)流动条件的不同可使升力回线的走向发生变化;(5)振动对分离有明显的抑制作用。 相似文献