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     

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（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。     

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．     

氮氧化合物在铜,银,镍,钯,铂面的吸附,脱附理论研究

采用ＡＳＥＤ－ＭＯ量子化学方法对氮（Ｎ２）和氮氧化合物（ＮＯｘ）在Ｃｕ,Ａｇ,Ｎｉ,Ｐｄ,Ｐｔ５种金属（１１１）面上的吸附态进行了系列研究,计算结果表明：在汽车尾气净化的催化处理过程中,当用铜,银,镍,钯,铂等金属作催化剂将ＮＯｘ转化为Ｎ２时,以金属Ｐｔ为最好。用铂作催化剂将ＮＯ还原成Ｎ２时,可得如下反应机理：ＮＯ分子首先吸附在Ｐｔ表面,然后吸附分子ＮＯ的Ｎ－Ｏ键中Ｏ原子。     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.     

Real-time restoration of rotational blurred image using gradient-loading

The key to the restoration of rotational motion blurred image is how to restore the image under a low cost and to correct the irreversibility of the degradation function matrix.Based on the special qualities of degradation function matrix and precise deduction in space-domain, we present a new approach using gradient-loading for restoration of rotational blurred image.By easily adding a gradient operator, the irreversibility of the original matrix is corrected and can be applied for inverse filtering then.Gradientloading is the optimized approach which combines the advantages of both the approaches using constrained least square filtering and traditional diagonal-loading.Compared with the approach using least square filtering, its peak signal-to-noise ratio (PSNR) is improved from 3.18 to 6.46dB, while the computing time is reduced to 1/2-1/3.Experimental results demonstrate the effectiveness, noise-resistibility, robustness, and low complexity of this approach, which make it more suitable for real-time environment.     

All-Optical Logic Device Using Bent Nonlinear Tapered Y-Junction Waveguide Structure

We propose an all-optical logic device made of a bent tapered Y-junction waveguide with a Kerr-type nonlinear interface. It could provide an AND gate, OR gate, and exclusive-OR (XOR) gate. We could obtain different transmission results by adjusting the bending angle. The numerical simulation results show that the device functions as AND, OR, and XOR gates.     

Real-time, continuous-wave terahertz imaging by a pyroelectric camera

Real-time, continuous-wave terahertz (THz) imaging is demonstrated. A 1.89-THz optically-pumped farinfrared laser is used as the illumination source, and a 124 × 124 element room-temperature pyroelectric camera is adopted as the detector. With this setup, THz images through various wrapping materials are shown. The results show that this imaging system has the potential applications in real-time mail and security inspection.