PdO引入对CuO／γ—Al2O3催化剂结构与性能的影响

运用ＰＴＲ,ＳＥＭ,ＸＲＤ阶梯扫描及ＣＯ和ＣＨ４氧化活性测定表征技术研究了ＣｕＯ／γ－Ａｌ２Ｏ３催化剂及负载ＰｄＯ对催化剂性能的影响。结果表明,ＣｕＯ／γ－Ａｌ２Ｏ３催化剂上引入不同含量的ＰｄＯ,使ＴＰＲ还原峰温欠下降。对载体上ＣｕＯ平均晶粒大小的测定表明随ＰｄＯ含量的增加,ＣｕＯ平均晶粒逐渐减小;ＳＥＭ对ＰｄＯ－ＣｕＯ／γ－Ａｌ２Ｏ３催化剂上Ｃｕ元素分布的面扫描测定亦证实了随ＰｄＯ含量的增加,催     

过渡金属Mn（Ⅲ）,Fe（Ⅲ）,Rh（Ⅱ）和Pd（Ⅱ）卟啉配合物的共振拉…

讨论了金属离子Ｍｎ（Ⅲ），Ｆｅ（Ⅲ），Ｒｈ（Ⅲ）和Ｐｄ（Ⅱ）原卟啉Ⅸ－二甲酯（ＰＰ）和四苯基卟啉（ＴＰＰ）配合物及Ｐｄ（Ⅱ）间氯四苯基卟啉（ＴＰＰｍ－ｃｌ）配合物的共振拉曼光谱。利用金属离子外层ｄ电子与卟啉环的作用，解释了配合物结构灵敏带的变化规律，同时讨论了不同卟啉及卟啉环上取代基团对结构灵敏带的影响。     

MAl2O4：Eu^2＋,RE^3＋,长余辉发光性质的研究

研究鳞石英结构碱土铝酸盐ＭＡｌ２Ｏ４：Ｅｕ＾２＋,ＲＥ＾＋（Ｍ＝Ｍｇ,Ｃａ,Ｓｒ,Ｂａ：ＲＥ＝Ｙ,Ｌａ,Ｃｅ,Ｐｒ,Ｎｄ,Ｓｍ,Ｇｄ,Ｔｂ,Ｄｙ,Ｈｏ,Ｅｒ,Ｔｂ,Ｄｙ,Ｈｏ,Ｅｒ,Ｔｍ,Ｙｍ,Ｙｂ,Ｌｕ）的荧光及长余辉发光性质。其发光由Ｅｕ＾２＋的４ｆ－５ｄ跃迁产生。ＲＥ＾３＋作为辅助激离子,提供合适的陷阱能级。即使用ＲＥ＾３＋的特性波长激发,在ＭＡｌ２Ｏ４：Ｅｕ＾３＋的发光中也观察不到ＲＥ＾３     

过渡金属Mn(Ⅲ),Fe(Ⅲ),Rh(Ⅲ)和Pd(Ⅱ)卟啉配合物的共振拉曼光谱研究

讨论了金属离子Ｍｎ（Ⅲ），Ｆｅ（Ⅲ），Ｒｈ（Ⅲ）和Ｐｄ（Ⅱ）原卟啉Ⅸ－二甲酯（ＰＰ）和四苯基卟啉（ＴＰＰ）配合物及Ｐｄ（Ⅱ）间氯四苯基卟啉（ＴＰＰｍ－ｃｌ）配合物的共振拉曼光谱。利用金属离子外层ｄ电子与卟啉环的作用，解释了配合物结构灵敏带的变化规律，同时讨论了不同卟啉及卟啉环上取代基团对结构灵敏带的影响。     

法拉第参数对几种四苯基卟啉金属络合物MCD谱的影响

本文测量了四苯基卟啉铁（ＦｅＴＰＰＣｌ），四苯基卟啉钴（ＣｏＴＰＰ）和四苯基卟啉镍（ＮｉＴＰＰ）的紫外可见吸收光谱和磁圆二色谱（ＭＣＤ），讨论了法拉第参数Ａ，Ｂ两项对Ｓｏｒｅｔ带和Ｑ带的综合影响。发现Ｂ项有参与且使ＭＣＤ谱中Ａ项的Ｓ曲线与波长λ轴交点的跃迁波长值较紫外可见光谱有红移和蓝移的特征。     

含R2dtc配体和V=O基的金属簇红外光谱研究

本文报道两类含Ｒ２ｄｔｃ配体的金属簇的红外光谱特点及某些规律,含Ｒ２ｄｔｃ的立方簇合物在４００－５００ｃｍ＾－１有较宽而弱的吸收,可归结于Ｍ－μ３Ｓ振动。Ｍ－Ｓｄｔｃ在３３０－３８０ｃｍ＾－１,Ｃ－Ｎ振动在１４７０－１５１０ｃｍ＾－１。二甲基ｄｔｃ配体立方的ｖ（Ｃ－Ｎ）与ｖ（Ｃ＝Ｓ）比值他二烷基ｄｔｃ立方烷的相应振动分别蓝移和红移,可归结于甲基超共轭效应所致。「Ｖ２Ｃｕ２Ｓ４（Ｒ２ｄｔｃ）２（ＰｈＳ）２」＾２－和「ＶＣｕ４Ｓ４（Ｒ２ｄｔｃ）ｎ（ＰｈＳ）４－ｎ」＾３－（ｎ＝０,１,２）的Ｍ－μ３Ｓ振动分别出现在４８０和４６５ｃｍ＾－１,可作为区别两类化合物的一个指标。另一类含（Ｒ２ｄｔｃ）２Ｖ２Ｏ２（μ－Ｓ）２单元的金属簇中,Ｖ－Ｏ伸缩频率在８４４－９７０ｃｍ＾－１范围内,（Ｅｔ４Ｎ）「Ｖ２Ｓ２Ｏ３（Ｅｔ２ｄｔｃ     

ELECTRON MOMENTUM SPECTRA OF EXCITED He(2~1S) AND He(2~3S)

ＥＬＥＣＴＲＯＮＭＯＭＥＮＴＵＭＳＰＥＣＴＲＡＯＦＥＸＣＩＴＥＤＨｅ（２１Ｓ）ＡＮＤＨｅ（２３Ｓ）ＣｈｅｎＺｈａｎｇｊｉｎＳｈｉＱｉｃｕｎＣｈｅｎＪｉＸｕＫｅｚｕｎＤｅｐａｒｔｍｅｎｔｏｆＭｏｄｅｒｎＰｈｙｓｉｃｓ，ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎ...     

元素在探针表面上的原子化机理研究

探针原子人经法是一种新技术，本文系统地总结了用探针原子化法研究Ａｕ（１Ｂ），Ｓｒ（ⅡＡ），Ｃｄ（ⅡＢ），Ａｌ（ⅢＡ），Ｌａ，Ｓｍ，Ｆｕ（ⅢＢ），Ｇｅ，Ｓｎ，Ｐｂ（ⅣＡ），Ｓｂ，Ｂｉ（ⅤＡ），Ｖ（ⅤＢ），Ｃｒ，Ｍｏ（ⅥＢ），Ｍｎ（ⅦＢ），Ｆｅ，Ｃｏ，Ｎｉ，Ｐｔ（Ⅷ）等２０个元素的原子化机理了起源于卤化物分解的元素有Ａｕ与Ｐｔ，起源于氧化物分解的元素有Ｃｄ，Ａｌ，Ｌａ，Ｓｍ，Ｅｕ，Ｇｅ，Ｍｎ与Ｆｅ。     

新型（Pb，Cd）－1222相化合物的制备、结构和电学性质

本文成功地合成了一系列新型Ｐｂ－１２２２相层状铜氧化物（Ｐｂ０．５Ｃｄ０．５）（Ｓｒ０．９Ｒ０．１）２（Ｒ＇０．７Ｃｅ０．３）２。Ｃｕ２Ｏｘ，Ｒ＝Ｒ＇＝Ｙ，Ｐｒ，Ｓｍ，Ｅｕ，Ｇｄ，Ｄｙ，Ｈｏ以及（Ｒ，Ｒ’）＝（Ｌａ，Ｅｕ），（Ｓｍ，Ｇｄ），（Ｓｍ，Ｅｕ），（Ｌａ，Ｇｄ），（Ｅｕ，Ｇｄ），（Ｎｄ，Ｅｕ），（Ｎｄ，Ｄｙ），（Ｎｄ，Ｙ），（Ｎｄ，Ｅｒ）．Ｘ－射线衍射和电子衍射表明它们属于四方晶系，其结构与（Ｐｂ，ＣＵ）－１２２２相结构相似．其中（Ｒ＇，Ｒ＇）＝（Ｅｕ，Ｇｄ）的样品在氧气中成相得到２３Ｋ的超导转变临界温度．     

新型（Pb,Cd）—1222相化合物的制备,结构和电学性质

本成功地合成了一系列新型Ｐｂ－１２２２相层状铜氧化物（Ｐｂ０．５Ｃｄ０．５）（Ｓｒ０．９Ｒ０．１）２（Ｒ‘０．７Ｃｅ０．３）２Ｃｕ２Ｏｚ，Ｒ＝Ｒ’＝Ｙ，Ｐｒ，Ｓｍ，Ｅｕ，Ｇｄ，Ｄｙ，Ｈｏ以有（Ｒ，Ｒ‘）＝（Ｌａ，Ｅｕ），Ｓｍ，Ｇｄ），（Ｓｍ，Ｅｕ），（Ｌａ，Ｇｄ），（Ｅｕ，Ｇｄ），（Ｎｄ，Ｄｙ），（Ｎｄ，Ｙ），（Ｎｄ，Ｅｒ）。     

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.     

Research on beamforming method for dual-line array with space mismatch between the two line arrays

The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results.     

Retrieval of ultraviolet skylight radiances and O3 slant column densities from balloon-borne limb spectrometer

With a novel light-weight and absolutely calibrated ultraviolet （UV） spectrometer, UV skylight radiances and O3 slant column densities are measured by balloon-borne limb measurements in Xinjiang area, China. UV skylight radiances measured at the height of 31 km are compared with the results from Modtran in the wavelength range from 290 to 420 nm. O3 slant column densities are derived from radiance spectra in the Huggins bands （320 - 335 nm） using differential optical absorption spectroscopy method. And the parameter exhibits a good correlation with the same value simulated by radiative transfer model （Tracy）. The O3 profile simultaneously measured by an O3 sonde is used as input in Tracy calculations. The O3 sonde is launched on the same balloon.     

Design optimization of highly sensitive LSPR enhanced surface plasmon resonance biosensors with nanoholes

For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanoparticles and nanogratings enhancement have been proposed recently.But in practice, these structures have obvious disadvantages.In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parameters on the performance is investigated by using rigorous coupled wave analysis (RCWA).Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters.The results indicate that significant sensitivity increase is associated with localized surface plasmons (LSPs) excitation mediated by nanoholes.Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves' width are obtained simultaneously under optimized structural parameters.     

Polymer gratings based on photopolymerization for low-order distributed feedback polymer lasers

Novel polymer distributed feedback(DFB)gratings are fabricated based on photopolymerization to reduce lasing threshold of polymer lasers.A photopolymer formulation sensitive to 355-nm ultraviolet(UV)light is proposed for the fabrication of polymer gratings and it can be used to form polymer films by spin-coating process.A very low surface-relief depth ranging from 12.5 to about 1.0 nm has been demonstrated with a refractive-index modulation of about 0.012.The experimental results indicate that such polymer gratings have promising potentials for the fabrication of low-order DFB organic semiconductor lasers.     

A novel methodology for photometric compensation of projection display on patterned screen

We propose a novel methodology based on the projector-camera (ProCam) system to address the photometric compensation issue for the projection display on the patterned screen.The patterned screen is treated as the combination of a perfect white screen and a color modulator.The perfect white screen is used to automatically and accurately characterize the ProCam system offline using the polynomial model,and the parameters of the color modulator can be efficiently recovered by employing only two gray images based on the linear reflectance model.The experimental results show that the color artifacts of the display image can be greatly improved with this methodology,which demonstrates its feasibility and validity in the photometric compensation.     

Direction-of-arrival estimation using matrix spatial prefiltering approach

An approach to direction-of-arrival （DOA） estimation for multiple narrowband farfield signals is proposed. The technique uses a novel matrix spatial prefiltering approach. Specifically, a matrix filter is designed to spatially filter the incoming data snapshots. The un-wanted components arriving from the stopband angular sectors are attenuated and the desired components from the angular sector of interest pass with minimal distortion. The matrix filter spatially filters the element-space data and the output reserves the element-space data property, which makes it very useful by passing sensor data through a spatial prefilter prior to applying many other array processors to attenuate interferences and improve system performance. Several examples of DOA estimation problem are presented to illustrate the performance of the proposed spatial prefiltering approach. Results of simulation and real data show that the pre-filter can efficiently attenuate the spatial interferences and significantly improve the estimation and resolution capability of DOA estimators at low signal-to-noise ratios for the sources located inside the passband sector. In addition, the use of spatial prefilter makes it possible to estimate DOAs for multiple sources more than the number of the elements of an array.     

Quantum efficiency calibration of opto-electronic detector by means of correlated photons method

A new calibration method of detectors can be realized by using correlated photons generated in spontaneous parametric down-conversion (SPDC) effect of nonlinear crystal.An absolute calibration system of detector quantum efficiency is performed.And its principle and experimental setup are introduced.A continuouswave (CW) ultraviolet (351 nm),diode-pumped,frequency-doubled,and solid-state laser is used to pump BBO crystal.The quantum efficiencies of the photomultiplier at 633,702,and 789 nm are measured respectively.The coincidence peaks are observed using coincidence circuit.Some measurement factors including the filter bandwidth of trigger channel,the detector position alignment and polarization of the pump light are analyzed.The uncertainties of this calibration method are also analyzed,and the relative uncertainties of total calibration are less than 5.8%.The accuracy of this method could be improved in the future.