纳米混合分子聚集体材料中弗兰克尔激子迁移的相位弛豫

在有机染料ＰＩＣ－１中引入其衍生物ａｚａＰＩＣ－Ｉ形成能量势垒，改变在混合分子聚集体中ＰＩＣ－Ｉ的Ｊ－聚集体的实体长度。用双调制外差检测的累积光子回波技术研究了相干弗兰克尔激子失相过程。观测到激子失相时间Ｔ２随ａｚａＰＩＣ－１克分子数的增大从６０ｐｓ变为２２４ｐｓ。     

有机纳米分子聚集体PIC-I的Raman光谱研究

本文从分子聚集体ＰＩＣ－Ｉ的吸收光谱可观测到Ｊ－带的红移和窄化,并可算出１３６８ｃｍ－１振模,以及本实验条件下聚集体单体数目为Ｎ≈３链长为３×０．３ｎｍ＝０．９ｎｍ。测量了ＰＩＣ－Ｉ聚集体的荧光光谱,将它与吸收光谱相比较可以看出,聚集体吸收带（５７２．５ｎｍ）和荧光发射带（５７２．５ｎｍ）是共振的。系统地研究了ＰＩＣ－Ｉ聚集体的喇曼光谱（１００～１８００ｃｍ－１）,验证了振动模 １３６８ｃｍ－１的存在。     

痕量钼的在线离子交换预浓缩流动注射—电感耦合等离子体光谱测定

本文采用双柱在线离子交换预浓缩ＦＩＡ－ＩＣＰ系统，建立了水及土壤浸出液中痕量钼的测定方法。用内装Ｄｏｗｅｘｌ（Ｃｌ＾－１型）阴离子交换树脂微型柱吸附待测元素，然后用洗脱剂（１．９ｍｏｌ／Ｌ氯化铵－０．４ｍｏｌ／Ｌ柠檬酸铵混合液＾［５］）洗脱。在采样频率为１２样／小时的速度下，浓缩倍数可达５０倍。样品（自来水）回收率为９０－１１０％；在０．２μｇ／ｍｌ水平时，变异系数为５．３％（ｎ＝１１）。     

四—（对—羟基苯基）卟啉在水／三氟乙酸溶液中J—聚集的光谱研究

本文研究了四－（对－羰基苯基）卟啉（ＴＣＰＰ）在Ｈ２Ｏ／ＣＦ３ＣＯＯＨ、Ｈ２Ｏ／ＣＣＩ３ＣＯＨ和Ｈ２Ｏ／ＣＨ３ＣＯＯＨ溶液中的ＵＶ－Ｖｉｓ吸收光谱、荧光光谱和拉曼光谱。实验表明,ＴＣＰＰ在Ｈ２Ｏ／ＣＨ３ＣＯＯＨ和Ｈ２Ｏ／ＣＣＩ３ＣＯＯＨ溶液中以分子态的Ｎ－质子化卟啉Ｈ８ＴＣＰＰ＾２＋存在,而在Ｈ２Ｏ／ＣＦ３ＣＯＯＨ中则形成Ｈ８ＴＣＰＰ＾２＋的Ｊ－聚集体。Ｊ－聚集体显示,ＵＶ－Ｖｉｓ吸收光谱和荧光光     

流动注射（FI）—在线柱预富集ICP—AES体系中的去溶效应研究

本文设计了一种简易的加热／冷凝去溶装置，并使之与流动注射（ＦＩ）－柱预富集－ＩＣＲＰ－ＡＥＳ）体系联接。研究了在不同情况下进样体积、去溶温度、载液流速等对分析信号强度、检出限和精密度的影响，并与非去溶体系相比较，去溶温度为１２０℃时，体系的去溶效率为３４．２％，进样效率为７２．５％；方法的检测限比非去溶体系改善近７倍。实验结果还表明，ＦＩ－柱预富集－去溶ＩＣＰ－ＡＥＳ体系获得了ｎｇ／ｍｌ～亚ｎｇ／     

ZnSe－ZnTe多量子阱室温下的反射型皮秒激子光双稳

本文首次研究了ＺｎＳｅ－ＺｎＴｅ多量子阱在室温下的反射型皮秒激子光双稳，实验结果表明，ＺｎＳｅ－ＺｎＴｅ多量子阱在室温下的反射型皮秒光双稳的阈值光强和对比度分别为１．１ＭＷ／ｃｍ２和６：１．根据测量得到的ＺｎＳｅ－ＺｎＴｅ多量子阱在室温下的激子吸收光谱及激子的非线性吸收理论，归结ＺｎＳｅ－ＺｎＴｅ多量子阱室温下的皮秒光双稳的主要非线性机理为ＺｎＳｅ－ＺｎＴｅ多量子阱的激子饱和吸收引起的折射率变化．     

室温CdxZn1—xTe／ZnTe多量子阱光学双稳态的研究

研制了室温ＣｄｘＺｎ１－ｘＴｅ／ＺＮＴｅ多量子阱法布里－珀罗腔光双稳器件，并在该器件上观察到皮秒一级的室温激子光双稳。研究结果表明，ＣｄＺｎ１－ｘＴｅ／ＺｎＴｅ多量子阱光双稳器件的光双稳值和对比度分别为３６３ｋＷ／ｃｍ＾２和４：１。根据ＣｆｘＺｎ１－ｘＴｅ／ＺｎＴｅ多量子阱的吸收谱和激子非线性理论，归结了ＣｄｘＺｎ１－ｘＴｅ／ＺｎＴｅ多量子阱光双稳的主要非线性机理为激子的饱和和吸收。     

流动注射（FI）－在线柱预富集ICP－AES体系中的去溶效应研究

本文设计了一种简易的加热／冷凝去溶装置，并使之与流动注射（ＦＩ）－柱预富集－ＩＣＰ－ＡＥＳ体系联接。研究了在不同情况下进样体积、去溶温度、载液流速等对分析信号强度、检出限和精密度的影响，并与非去溶体系相比较。结果指出，去溶温度为１２０℃时，体系的去溶效率为３４．２％，进样效率为７２．５％；方法的检测限比非去溶体系改善近７倍。实验结果还表明，ＦＩ－柱预富集－去溶ＩＣＰ－ＡＥＳ体系获得了ｎｇ／ｍｌ～亚ｎｇ／ｍｌ级的检出限，可望用于超痕量组分的测定。     

Cd_xHg_（1－x）Te／SiO_2固溶体微晶掺杂玻璃三阶非线性光学性质的

本文首次报道了对采用溶胶凝胶和原位生长工艺制备的Ｃｄ_ｘＨｇ_(１－ｘ)Ｔｅ／ＳｉＯ_２固溶体微品掺杂玻璃进行的三阶非线性光学性质实验研究及其结果。利用回返式简并四波混频技术，测得该固溶体掺杂玻璃的三阶非线性极化率的值为１０￣（－１２）ｅｓｕ量级。此结果比纯ＳｉＯ_２基体提高了２个数量级。表明该固溶体掺杂玻璃三阶非线性明显增强，在同样条件下，测得ＣＳ_２的三阶非线性极化率ｘ（３）为（１．７±０．２）×１０￣(－１２)ｅｓｕ，与国际上报道完全一致。     

动物脑组织中微量钙的ICP—AES法测定

本文利用ＩＣＰ－ＡＥＳ法测定了大白鼠脑组织中的微量钙，并对经典的Ｃａ－ＰＯ４干扰体系在ＩＣＰ－ＡＥＳ中的影响进行了实验，结果表明，样品消解后可直接进样，磷不影响钙的测定，方法的ＲＳＤ为１．１６％，样品加标回收率为９７％，优化实验条件下，对降低干扰，提高分析结果的准确度是至关重要的。     

Collagen type I amide I band infrared spectroscopy

Collagen fiber structure and organization have been found to vary in different tendon types. Differences have been reported in the FT-IR spectra of the amide I band of collagen-containing structures. In the present study, the FT-IR spectral characteristics of the amide I band of the bovine flexor tendon and the extended rat tail tendon were compared by using the diamond attenuated total reflectance technique. The objective was to associate FT-IR spectral characteristics in tendons with their different collagen fiber supraorganization and biomechanical properties. Nylon 6 and poly-L-lysine were used as polyamide models. Each of these materials was found to exhibit molecular order and crystallinity, as revealed by their birefringence. The following FT-IR parameters were evaluated: amide I band profile, absorption peaks and areas, and the 1655 cm?1/1690 cm?1 absorbance ratio. The amide I area and the 1655 cm?1/1690 cm?1 absorbance ratio were significantly higher for the bovine flexor tendon, indicating that its collagen fibers are richer in pyridinoline-type cross-linking, proline and/or hydroxyproline and H-bonding, and that these fibers are more packed and supraorganizationally ordered than those in the rat tail tendon. This conclusion is additionally supported by differences in collagen solubility and biochemical/biomechanical properties of the tendons.     

High-pressure gas lasers on Ar I,Xe I,and Kr I transitions

Lasing has been obtained in a high pressure (up to 17 atm) gas on Ar I, Xe I, and Kr I transitions. The gas was excited by a transverse discharge with volume preionization by a discharge through a dielectric. New laser lines belonging to Ar I (9123, 9658, 10470, and 11488 Å), Xe I (8232 Å), and Kr I (8929 Å) have been found. The dependences of the spectral and energetic characteristics of the He-Ar laser on the conditions of gas pressure and discharge have been investigated in detail. At high pressures, wide (about 50 HGz) laser lines have been found as well as high power (>10⁵ W) laser lines. Time characteristics of the radiation have been investigated and optimal conditions for the generation power have been defined.     

Wedges I

The wedge problem, that is, the propagation of radiation or particles in the presence of a wedge, is examined in different contexts. Generally, the paper follows the historical order from Sommerfeld's early work to recent stochastic results—hindsights and new results being woven in as appropriate. In each context, identifying the relevant mathematical problem has been the key to the solution. Thus each section can be given both a physics and a mathematics title: Section 2: diffraction by reflecting wedge; boundary value problem of differential equations; solutions defined on mutiply connected spaces. Section 3: geometrical theory of diffraction; identificiation of function spaces. Section 4: path integral solutions; path integration on multiply connected spaces; asymptotics on the boundaries of function spaces. Section 5: probing the shape of the wedge and the roughness of its surface; stochastic calculus. Several propagators and Green functions are given explicitly, some old ones and some new ones. They include the knife-edge propagator for Dirichlet and Neumann boundary conditions, the absorbing knife edge propagator, the wedge propagators, the propagator for a free particle on a -sheeted Riemann surface, the Dirichlet and the Neumann wedge Green function.Supported in part by NSF grant PHY84-04931.Supported in part by SERC grant GR/D 15911.Supported in part by a NSERC (Canada) Fellowship.Supported in part by SERC grant B/83301669.     

I: METHODOLOGY

Since standard molecular simulations use different energy expressions for charge and gradient calculations, there are severe problems such as incompleteness in the optimization and simulation of the system with electrostatic (ES) interaction. Here, a new concept is proposed to solve this problem. The consistent charge equilibration (CQEq) equation has been derived which uses the same energy expression for both charge and gradient calculations. The ES energy is given by the atomic partial charge shielded with a nuclear charge described by a normalized S type Slater function located at each atomic site. The partial charge is determined by the variational principal for the ES energy with a constraint that the total sum of the partial charges is constant. Also the first derivative has been determined for the ES energy to the internal coordinates from the same ES energy expression. Although the CQEq is a little heavier than the original QEq for the charge calculation, the CQEq completely satisfies the variational principle for the ES energy of a set of partial charge, and satisfies the consistency requirement in the optimization of the system with ES interaction. A new code has been created and applied to test cases.     

Quantum leptogenesis I

Thermal leptogenesis explains the observed matter–antimatter asymmetry of the universe in terms of neutrino masses, consistent with neutrino oscillation experiments. We present a full quantum mechanical calculation of the generated lepton asymmetry based on Kadanoff–Baym equations. Origin of the asymmetry is the departure from equilibrium of the statistical propagator of the heavy Majorana neutrino, together with CP violating couplings. The lepton asymmetry is calculated directly in terms of Green’s functions without referring to “number densities”. Compared to Boltzmann and quantum Boltzmann equations, the crucial difference are memory effects, rapid oscillations much faster than the heavy neutrino equilibration time. These oscillations strongly suppress the generated lepton asymmetry, unless the standard model gauge interactions, which cause thermal damping, are properly taken into account. We find that these damping effects essentially compensate the enhancement due to quantum statistical factors, so that finally the conventional Boltzmann equations again provide rather accurate predictions for the lepton asymmetry.