数字微镜近红外光谱仪光学系统设计与实验

针对传统光谱仪体积大、成本高、检测速度慢、需样品前处理等不足,提出了利用数字微镜面阵(DMD)实现光谱谱面分割分时选通的近红外光谱仪光学系统.首先,对比传统光路介绍单探测器微型光谱仪系统测量原理;然后结合DMD特性提出光路方案,根据几何光学原理进行初步光学元件选型和光路结构设计,利用ZEMAX光学软件对光路进行仿真,确...     

关于超音速多普勒效应的思考

超音速多普勒效应由于其不便于测量,基本停留在纯理论分析阶段,导致人们产生了一些错误的观点.本文通过逻辑分析、计算机软件模拟等手段,对超音速多普勒效应的音频时序进行了分析研究,找出了错误观点产生的原因,作出了相应的解释,并对错误观点进行了修正,提供了解决方案.     

Study of radiation background at the north crossing point of the BEPCⅡ in collision mode

Understanding the radiation background at the north crossing point (NCP) in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium (HPGe) detector, and in turn of great significance for long-term stable running of the energy measurement system. Therefore, as the first step, a NaI(Tl) detector is constructed to continuously measure the radiation level of photons as background for future experiments. Furthermore, gamma and neutron dosimeters are utilized to explore the radiation distribution in the vicinity of the NCP where the HPGe detector will be located. Synthesizing all obtained information, the shielding for neutron irradiation is studied based on model-dependent theoretical analysis.     

GISAXS and SAXS studies on the spatial structures of Co nanowire arrays

The spatial structures of magnetic Co nanowire array embedded in anodic aluminium membranes were investigated by grazing incidence small angle X-ray scattering (GISAXS) and conventional small angle X-ray scattering (SAXS) techniques. Compared with SEM observation, the GISAXS and SAXS measurements can get more overall structural information in a large-area scale. In this study, the two-dimensional GISAXS pattern was well reconstructed by using the IsGISAXS program. The results demonstrate that the hexagonal lattice formed by the Co nanowires is distorted (a ≈ 105 nm, b ≈ 95 nm). These Co nanowires are isolated into many structure domains with different orientations with a size of about 2 μm. The SAXS results have also confirmed that the nanopore structures in the AAM can be retained after depositing Co nanowires although the Co nanowires can not completely but only just fill up the nanopores. These results are helpful for understanding the global structure of the Co nanowire array.     

Fast computation of observed cross section for ψ′ → PP decays

It has been conjectured that the relative phase between strong and electromagnetic amplitudes is universally -90° in charmonium decays. ψ′ decaying into a pseudoscalar pair provides a possibility to test this conjecture. However, the experimentally observed cross section for such a process is depicted by the two-fold integral, which takes into account the initial state radiative (ISR) correction and energy spread effect. Using the generalized linear regression approach, a complex energy-dependent factor is ...     

A New Capillary Electrophoresis Apparatus with Piezoelectric Ceramics High Voltage Source and Amperometric Detector

IntroductionHighperformancecapiliar}'electrophoresis(HPCE)isanewanalyticaltechnology'rapidly'developedinrecentyears.Withtheadvantagesofsmallsample.highsensitivity,highresolution.rapidanalysisandverycheaprunning,ithasbeenappliedinchemistry'.lifescienc...     

A new theory for symmetry orbital and tensor (Ⅱ)——Symmetric reduction of molecular integrals and self-consistent field calculations

The symmetry orbital-symmetry orbital tensor method is applied to the evaluation of molecular integrals (one-electron and two-electron integrals) and the symmetry-orbital-tensor and self-consistent-field (SOT-SCF) calculations. A calculation scheme is proposed to simplify the evaluation of integrals and a key equation is derived to reduce the computation efforts in SCF iterations. According to the key equation, compared with the traditional SCF method, the computation efficiencies including CPU timing and external disk (or internal memory) requirement increase in the magnitude of the square of the order of a point group. The new SOT method is expected to be useful in the theoretical calculations of large molecular systems of high point group symmetries.     

ITO靶材黑化物的X射线光电子能谱研究

利用X射线光电子能谱（XPS）分析了ITO靶材黑化物的化学组成，结果表明黑化物由In、Sn、O和C组成，相对原子百分含量In为34．35％，Sn为2．74％，O为52．65％，C为10．26％；In、Sn处于亚氧化状态；C有部分氧化。与原始靶材相比，黑化物的元素组成和化学状态发生了明显的变化。择优溅射最可能引起成分比例失常，真空残余的合C气体和泵油蒸汽被认为是污染C的直接来源。     

Synthesis of high‐molecular‐weight linear methacrylate copolymers with spiropyran side groups: Conformational changes of single molecules in solution and on surfaces

P(BMA‐co‐HEMA‐spiropyran) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization of butyl methacrylate (BMA) and 2‐(trimethylsilyloxy)‐ethyl methacrylate (HEMA‐TMS), removal of the TMS‐protective groups, and the polymer analogous esterification of the hydroxyethyl side chains with a spiropyran containing a carboxylic acid group. UV‐induced conformational changes of the synthesized macromolecules and low‐molecular‐weight spiropyran molecules were studied. Rate constants and half‐life times of the ring closure reaction from zwitterionic merocyanine to the spiropyran species were determined in the presence and absence of mica‐dispersed particles in toluene both with the free spiropyran and the polymer‐bound spiropyran. Scanning force microscopy was used to visualize the conformation of spiropyran‐decorated single macromolecular chains and agglomerated polymer‐bound merocyanine adsorbed on mica. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1274–1283, 2009