一种光学平台的力学稳定性分析

光学平台稳定性使用要求很高，结构形式复杂，使用环境苛刻，受不同类型载荷作用，对结构设计和加工工艺的要求非常严格。介绍了利用ANSYS结构分析软件对该光学平台在不同的简化结构条件下的计算机数值模拟结果，为其工程研制提供了理论依据。     

松香试样的预处理及痕量砷的测定方法研究

提出松香样品添加混合助剂MgCO3 Mg(NO3 ) 2 进行干灰化预处理 ,并将此法与硝酸 高氯酸的湿消解法和仅添加Mg(NO3 ) 2 的干灰化法进行了比较。结果表明 ,本法在抑制砷的挥发方面 ,比仅用Mg(NO3 ) 2作为灰化助剂的干灰化法效果更好 ,砷的回收率在 94 %～ 10 5 % ;比用硝酸 高氯酸湿消解法分解试样更彻底 ,可以避免剩余酸除去时引起的砷损失。试验还表明 ,HG AFS测As的检出限DL =0 31ng·mL-1,松香中的砷不用富集便可进行测量 ,对国家标准物质桃叶GBW 0 85 0 1中砷的测定结果与推荐值一致 ,方法的相对标准偏差RSD =2 6 %～ 4 4 %。     

新型含氧亚甲基和亚胺桥键液晶化合物分子结构与光谱的密度泛函理论研究

采用密度泛函理论方法在B3LYP/6-31G*水平上对6个新型含氧亚甲基和亚胺桥键液晶化合物分子的几何结构进行优化计算,讨论了取代基H,CH3,CH3O,C2H5O,NO2,Cl对分子电荷、前线轨道能量和电子吸收光谱等性质的影响.在此基础上使用含时密度泛函理论方法计算了分子第一激发态的电子垂直跃迁能,得到最大吸收波长λmax.计算表明,取代基的引入导致最大吸收波长红移.     

电子性作用对MgB2超导体同位素效应的影响

通过引入电子性作用V_c,在弱耦合条件下导出了两带模型的T_c公式和同位素效应指数公式,计算了超导体MgB_2的超导转变温度和同位素效应,得到了与实验相符的结果。结果表明,带内电子性作用比带间电子性作用对同位素效应指数的影响要大。     

Dynamic Mechanism of Sustainable Molecular Orientation Generated From Cyclic Rotational States

Recently, two papers presented by Ortigoso et al. [Phys. Rev. Lett. 93 （2004） 073001 and Phys. Rev. A 72 （2005） 053401] develop a novel strategy in which the best sustainable molecular alignment/orientation has been achieved. We intend to analyse the dynamic mechanisms, including those Ortigoso et al. have not clarified.     

Ground-State Properties of Ca Isotopes and the Density Dependence of the Symmetry Energy

A relativistic mean field model is used to study the ground-state properties of neutron-rich nuclei in Ca isotopes. An additional isoscalar and isovector nonlinear coupling has been introduced in the relativistic mean field model, which could soften the symmetry energy, while keep the agreement with the experimental data. The sensitivity of proton and neutron density distributions and single particle states in Ca isotopes to the additional isoscalarisovector nonlinear coupling term is investigated. We found that the binding energies, the density distributions of single particle levels are strongly correlated with the density dependence of the symmetric energy in nuclear matter.     

Preparation of Cu（In,Ga）Se2 Thin Film Solar Cells by Selenization of Metallic Precursors in an Ar Atmosphere

Cu（In, Ga）Se2 thin films are deposited on Mo-coated glass substrates by Se vapour selenization of sputtered metallic precursors in the atmosphere of Ar gas flow under a pressure of about 10 Pa. The in situ heat treatment of as-grown precursor leads to the formation of a better alloy. During selenization, the growth of CuInSe2 phase preferably proceeds through Se-poor phases as CuSe and InSe at relatively low substrate temperature of 250℃, due to the absence of In2Se3 at intermediate stage at low reactor pressure. Subsequently, the Cu（In,Ga）Se2 phase is produced by the reactive diffusion of CuInSe2 with a Se-poor GaSe phase at high temperature of up to 560℃. The final film exhibits smooth surface and large grain size. The absorber is used to fabricate a glass/Mo/Cu（In, Ga）Se2/CdS/ZnO cell with the total-area efficiency of about 7%. The low open-circuit voltage value of the cell fabricated should result from the nonuniform distribution of In and Ga in the absorber, due to the diffusion-controlled reaction during the phase formation. The films, as well as devices, are characterized.     

Effect of Incident Intensity on Films Growth in Pulsed Laser Deposition

Incident intensity, defined by the amount of particles deposited per pulse, is an important parameter in the film growth process of pulsed laser deposition （PLD）. Different from previous models, we investigate the irreversible and reversible growth processes by using a kinetic Monte Carlo method and find that island density and film morphology strongly depend on pulse intensity. At higher pulse intensities, lots of adatoms instantaneously diffuse on the substrate surface, and then nucleation easily occurs between the moving adatoms resulting in more smaller-size islands. In contrast, at the lower pulse intensities, nucleation event occurs preferentially between the single adatom and existing islands rather than forming new islands, and therefore the average island size becomes larger in this case. Additionally, our results show that substrate temperature plays an important role in film growth. In particular, it can determine the films shape and weaken the effect of pulse intensity on film growth at the lower temperatures by controlling the mobility rate of atoms. Our results can match the related theoretical and experimental results.     

PGAI瞬发伽玛射线活化成像技术理想化模型的模拟

为了讨论PGAI技术分析的准确性,并验证冷中子和热中子应用于PGAI技术的可行性,通过蒙特卡罗模拟计算软件对PGAI技术理想化模型进行了研究,采用高准直的冷中子及热中子束和高纯锗探测器,对一块5 cm× 5 cm×1 cm均匀铁单质样品进行了模拟计算及图像重建,选取的等效体积大小为1 cm×1 cm×1 cm。结果显示：两种能量中子可以用于PGAI技术实现元素分布测量,但无论使用何种能量中子,由于物料体效应带来的中子自屏效应、中子散射效应以及伽马射线自吸收作用,即便在对均匀单质样品进行测量时,图像重建结果也无法保证各位置元素响应的一致性。因此,在后续工作中,需理清PGAI物理机制,建立相应的修正模型。     

卫星太阳能电池阵破损自动检测系统的研究

介绍了国内首次研制的卫星太阳能电池阵破损自动检测系统的检测原理、系统结构与设计及现场试用结果。系统采用专用照明系统,电池阵列经光学系统清晰成像至CCD传感器上,经信号放大、A/D转换后输入计算机管理和控制系统。图像传感探头自动扫描整块电池板,并由距离传感器控制,始终保持采集图像清晰。利用特有的系统控制和检测软件,处理每幅电池图像信息,检测结果通过列表形式给出损伤电池的位置、破损类型、破损度等参数。现场试验结果表明:该系统的检出率达98.5%以上,检测速度为每分钟20片电池,达到了快速、高精度、自动化检测太阳能电池阵的使用要求。