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81.
82.
CongZhan Liu YiFei Zhang XuFang Li XueFeng Lu Zhi Chang ZhengWei Li AiMei Zhang YongJie Jin HuiMing Yu Zhao Zhang MinXue Fu YiBao Chen JianFeng Ji YuPeng Xu JingKang Deng RenCheng Shang GuoQing Liu FangJun Lu ShuangNan Zhang YongWei Dong TiPei Li Mei Wu YanGuo Li HuanYu Wang BoBing Wu YongJie Zhang Zhi Zhang ShaoLin Xiong Yuan Liu Shu Zhang HongWei Liu YiJung Yang Fan Zhang 《中国科学:物理学 力学 天文学(英文版)》2020,(4):20-34
The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments. 相似文献
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84.
lnthepreviouspaper',wereportedtheintramolecularcyclizationsofamide4anditscis-eneisomerinanattempttosynthesizehomoclausenamideandzetaclausenamide2.Inordertostudytherelationshipbetweenthestereochemistryandtheilltramolecularcyclizationofthisseriesofcompounds,theamides5(cis-oxirane,trans-ene)and8(cis-oxirane,cis-ene)wereprepared,andtheirintramolecularcyclizationswerereportedinthispaper.Theamide5withm.p.152.O-l54.O"CwasobtainedfromDarzen'scondensationofcompound3withPhCHOinMeOHatl5-2OoCwithMeO… 相似文献
85.
通过二元系和三元系结构参数计算四元系量子阱结构的晶格常数、禁带宽度等,设计了InGaAsSb/AlGaAsSb结构的MBE生长参数及工艺,利用X射线双晶衍射和PL谱研究了InGaAsSb/AlGaAsSb多量子阱结构特性和光学特性。X射线双晶衍射谱中出现了8条卫星峰,表明制备的InGaAsSb/AlGaAsSb多量子阱结构具有良好的结晶质量。利用光致发光光谱方法对制备的样品的光学性质进行了表征,结果表明,不同组份的InGaAsSb/AlGaAsSb多量子阱的发光峰波长随组份的变化在1.6~2.28 μm范围内可调,样品PL谱的半峰宽最窄可达22 meV。 相似文献
86.
The effects of the magnitude of the uniaxial anisotropy of a ferromagnet and the cooling field on the noncollinearity between uniaxial anisotropy and induced unidirectional anisotropy in a ferromagnet/antiferromagnet bilayer system are investigated. A diagram of noncollinear anisotropies and relative negative (positive) exchange bias field dependence upon cooling field and uniaxial anisotropy of the ferromagnet is obtained. The numerical result shows that the emergence of noncollinear anisotropies originates from the action of the cooling field and uniaxial anisotropy of the ferromagnet. The noncollinearity strongly depends on the magnitude of cooling field and uniaxial anisotropy of the ferromagnet. Moreover, the effect of noncollinear anisotropies and applied field on asymmetric magnetization reversal is also investigated. Amazingly, when the magnetic field is applied collinearly with unidirectional anisotropy, the hysteresis loop of ferromagnet/antiferromagnet bilayers is always symmetric even if there are noncollinear anisotropies. Our results indicate that the asymmetry of the hysteresis loop only originates from the noncollinearity between the induced unidirectional anisotropy and the applied field, rather than from the noncollinearity between the uniaxial and unidirectional anisotropies. 相似文献
87.
The nonlinear propagation of planar and nonplanar (cylindrical and spherical) ion-acoustic waves in an unmagnetized electron–positron–ion–dust plasma with two-electron temperature distributions is investigated in the context of the nonextensive statistics. Using the reductive perturbation method, a modified nonlinear Schrödinger equation is derived for the potential wave amplitude. The effects of plasma parameters on the modulational instability of ion-acoustic waves are discussed in detail for planar as well as for cylindrical and spherical geometries. In addition, for the planar case, we analyze how the plasma parameters influence the nonlinear structures of the first- and second-order ion-acoustic rogue waves within the modulational instability region. The present results may be helpful in providing a good fit between the theoretical analysis and real applications in future spatial observations and laboratory plasma experiments. 相似文献
88.
脉冲激光烧蚀碲镉汞材料的等离子体发射谱 总被引:6,自引:0,他引:6
脉冲激光辐照处于不同背景气压下的Hg0.8Cd0.2Te材料表面,用时间和空间分辨诊断技术探测了激光照射后产生的等离子体发射谱,根据所获得的飞行时间谱测量了等离子体中粒子的出射速度,结果表明粒子速度随着出射距离的增加迅速减小,且背景气压对出射速度有很大的影响,而激光能量对粒子速度的影响不大。另外根据谱线的展宽计算了等离子体中的电子密度,结果表明,电子密度在激光辐照样品后的短时间内迅速减小,且电子密度最大的位置不是出现在靶的表面而是在距表面一定距离处。 相似文献
89.
90.
原子发射光谱内标法测量误差的研究 总被引:3,自引:1,他引:3
证明了原子发射光谱内标法的测量误差。当分析线和内标线的相对强度等于1时,测量误差最小。 相似文献