新型胺类毒品分子的结构、光谱和热力学性质研究

采用密度泛函理论B3LYP/6-31++G**方法对2-胺基苯基丙烷（a）、2-甲胺-1-苯基丙烷（b）、7-甲氧基- a -甲基-1,3-苯骈二氧杂环戊烯-5-乙胺（c）、2,5-二甲氧基- a -甲基苯乙酰胺（d）四个新型胺类毒品分子进行结构优化,并进行频率和热容、熵、焓、自由能等气态热力学性质计算,获得它们的红外光谱、电子光谱和分子轨道图,模拟出标准摩尔热容Cθpm、标准摩尔熵Sθm、标准摩尔焓Hθm等气态热力学性质与温度之间的函数关系式.     

新型含马来酰亚胺环氧树脂固化剂分子的结构、光谱和热力学性质研究

使用密度泛函理论,采用B3LYP/6-311++G**方法计算研究了N-(4-马来酰亚胺基苯基)缩水甘油胺(a)、4-马来酰亚胺基苯基缩水甘油醚(b)、N-(4-氨基苯基马来酰亚胺)二缩水甘油胺(c)三个新型含马来酰亚胺固化剂分子的几何结构、电子吸收光谱、热力学性质.获得了它们的稳定结构、红外光谱、电子光谱和分子轨道图,模拟出标准摩尔热容C_(pm)~θ、标准摩尔熵S_m~θ、标准摩尔焓H_m~θ等气态热力学性质与温度之间的函数关系式.     

一种含马来酰亚胺环氧树脂固化剂的合成与结构、光谱和热力学性质研究

以马来酸酐、对硝基苯胺、环氧氯丙烷为原料，首先合成出N-(4-硝基苯基)马来酰亚胺（NPMI）、再将其催化还原成N-(4-氨基苯基)马来酰亚胺（APMI），最后以APMI与环氧氯丙烷反应合成出一种新型的含马来酰亚胺环氧树脂固化剂 N-(4-氨基苯基马来酰亚胺)二缩水甘油胺（MPDGA）。采用密度泛函理论B3LYP/6-311++G(d , p)方法，研究了所合成的MPDGA分子的几何结构、电子结构及热力学性质。获得了它们的红外光谱、电子光谱和分子轨道图，以及标准摩尔热容Cθpm、标准摩尔熵Sθm、标准摩尔焓Hθm等气态热力学性质与温度的变化关系，同时获得了MPDGA分子的标准摩尔生成焓 和标准摩尔生成自由能 数据。     

一种含马来酰亚胺环氧树脂固化剂的合成与结构、光谱和热力学性质研究

以马来酸酐、对硝基苯胺、环氧氯丙烷为原料,首先合成出N-(4-硝基苯基)马来酰亚胺(NPMI)、再将其催化还原成N-(4-氨基苯基)马来酰亚胺(APMI),最后以APMI与环氧氯丙烷反应合成出一种新型的含马来酰亚胺环氧树脂固化剂N-(4-氨基苯基马来酰亚胺)二缩水甘油胺(MPDGA).采用密度泛函理论B3LYP/6-311++G(d,p)方法,研究了所合成的MPDGA分子的几何结构、电子结构及热力学性质.获得了它们的红外光谱、电子光谱和分子轨道图,以及标准摩尔热容C_(pm)~θ、标准摩尔熵S_m~θ、标准摩尔焓H_m~θ等气态热力学性质与温度的变化关系,同时获得了MPDGA分子的标准摩尔生成焓Δ_fH_m~θ和标准摩尔生成自由能ΔfGθm数据.     

2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的光谱

采用密度泛函理论在B3LYP/6-31+G*水平计算研究2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的结构、光谱、热力学性质.结果显示,优化得到的最稳定结构的三个环构处于同一平面,两个溴原子分别位于平面的上下两侧.气相中最低能量跃迁与最强吸收峰均出现在315 nm,对应HOMO到LUMO的电子跃迁,溶剂作用使其红移4—6 nm.热力学计算表明,标准摩尔焓、标准摩尔热容和标准摩尔熵等热力学性质与温度之间存在很好的二次函数关系.298.15 K,2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的标准摩尔生成焓和标准摩尔生成自由能分别为2708.95和2972.13 kJ/mol.     

2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的光谱

采用密度泛函理论在B3LYP/6-31+G*水平计算研究2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的结构、光谱、热力学性质.结果显示,优化得到的最稳定结构的三个环构处于同一平面,两个溴原子分别位于平面的上下两侧.气相中最低能量跃迁与最强吸收峰均出现在315 nm,对应HOMO到LUMO的电子跃迁,溶剂作用使其红移4—6 nm.热力学计算表明,标准摩尔焓、标准摩尔热容和标准摩尔熵等热力学性质与温度之间存在很好的二次函数关系.298.15 K,2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的标准摩尔生成焓和标准摩尔生成自由能分别为2708.95和2972.13 kJ/mol.     

2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的结构、光谱与热力学性质的理论研究

采用密度泛函理论在B3LYP/6-31+G*水平计算研究2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的结构、光谱、热力学性质.结果显示,优化得到的最稳定结构的三个环同在一个平面,两个溴原子偏离平面120°,分别位于平面两端正反方向.气相中最强吸收峰出现在315 nm,为S0到S1的电子跃迁,溶剂作用使其红移4～6 nm.热力学计算表明,标准摩尔焓、标准摩尔热容和标准摩尔熵分别与温度存在二次函数关系.298.15 K,2,5-二(4-溴甲基苯基)-1,3,4噁二唑分子的标准摩尔生成焓和标准摩尔生成自由能分别为2708.95和2972.13kJ.mol-1.     

4-甲氧基-2-磺酸基苯基重氮氨基偶氮苯的合成及其与汞(Ⅱ)的显色反应

合成了4-甲氧基-2-磺酸基苯基重氮氨基偶氮苯(MOSDAA),并对该试剂与汞(Ⅱ)的显色反应进行了研究.实验表明,在pH 11.5的Na2B4O7-NaOH缓冲溶液中,Triton X-100存在下,该试剂与汞(Ⅱ)形成3:1的红色络合物,其最大吸收波长位于520nm,表观摩尔吸光系数为2.56×105L·mol-1·cm-1,Hg(Ⅱ)在0-14μg/25mL范围内遵守比耳定律.     

N-(4-硝基苯基)马来酰亚胺分子结构、光谱和热力学性质的理论研究

N-(4-硝基苯基)马来酰亚胺是一种新合成的NPMI类化合物,在B3LYP/6-311++G~(**)水平对N-(4-硝基苯基)马来酰亚胺分子进行几何结构优化和频率、热力学性质计算,得到它的红外光谱、拉曼光谱和不同温度下的热力学性质.结果显示,该分子中两个C=O与五元环在同一个平面内,苯环上硝基中的N—O与六元环也在同一个平面内,五元环与六元环呈129.6°的二面角,整个分子不具有对称性;热容、熵、焓等热力学性质与温度之间存在很好的函数关系式.     

N-(4-硝基苯基)马来酰亚胺分子结构、光谱和热力学性质的理论研究

N-(4-硝基苯基)马来酰亚胺是一种新合成的NPMI类化合物，在B3LYP/6-311++G**水平对N-(4-硝基苯基)马来酰亚胺分子进行几何结构优化和频率、热力学性质计算，得到它的红外光谱、拉曼光谱和不同温度下的热力学性质。结果显示，该分子中两个C=O与五元环在同一个平面内，苯环上硝基中的N-O与六元环也在同一个平面内，五元环与六元环呈129.6的二面角，整个分子不具有对称性；热容、熵、焓等热力学性质与温度之间存在很好的函数关系式。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.