A polyene chain of canthaxanthin investigated by temperature-dependent resonance Raman spectra and density functional theory （DFT） calculations

We report on a temperature-dependent resonance Raman spectral characterization of the polyene chain of canthax- anthin. It is observed that all vibrational intensities of the polyene chain are inversely proportional to temperature, which is analyzed by the resonance Raman effect and the coherent weakly damped electron/lattice vibrations. The increase in intensity of the CC overtone/combination relative to the fundamental with temperature decreasing is detected and discussed in terms of electron/phonon coupling and the activation energy Uop. Moreover, the polyene chain studies using the density functional theory B3LYP/6-31 G＊ level reveal a prominent peak at 1525 cm-1 consisting of two closely spaced modes that are both dominated by C=C stretching coordinates of the polyene chain.     

含有5-甲基-3-吡唑甲酸的铅(Ⅱ)配合物:合成、结构和荧光性质

在不同含N辅助配体的存在下,将5-甲基-3-吡唑甲酸(H_2MPCA)与相应的铅(Ⅱ)盐反应制得了2个新的配合物:[Pb(HMPCA)_2(H_2O)_2]·H_2O (1)和[Pb(HMPCA)_2(phen)]·H_2O (2)(phen=菲咯啉)。双核配合物1中双核[Pb(μ_2-HMPCA)]_2单元在一对Pb…O次级键的作用下形成了一维链状结构,这些一维链在氢键的作用下进一步自组装成2D超分子结构。而单核化合物2在Pb…O次级键的作用下形成了Pb_2O_2平面,它们在π…π和氢键作用下堆积形成3D超分子结构。考察了配合物1和2的热稳定性、荧光性能。     

Ag2CO3/ZnBiO复合材料的制备及可见光催化性能的研究

采用新型一锅溶胶-凝胶法制备了Zn掺杂的β-Bi_2O_3(记为ZnBiO),并以ZnBiO为前驱体,利用简单的化学沉淀法制备了不同质量比的Ag_2CO_3/ZnBiO复合材料.通过XRD、SEM、DRS和PL对样品的晶体结构、微观形貌、光吸收能力及荧光性质进行了表征,并通过可见光催化降解亚甲基蓝实验探讨了Ag_2CO_3/ZnBiO复合材料的光催化作用机制.     

A Stable Porous Silicon Dielectric Reflector with a Photonic Band Gap Centred at 10μm

By pulsed anodic etching at low temperature, we prepared a porous silicon reflector with a photonic band gap centred in the long-wavelength infrared spectral region （centred at about 12 μm）. After proper oxidation process, the stable reflector structure, which can reflect electromagnetic wave from 8 μm to 12 μm （centred at 10 μm） within wide incidence angles （about 50°）, is obtained. The wavelength shift of absorption peak of Si-H and Si-O shows the influence of oxidation process and indicates the stability of oxidized porous silicon dielectric reflector, which offers possible applications for the room temperature infrared sensor.     

四氯化碳ν_1振动在费米共振光谱特性参数中的作用

研究了CCl4的ν1+ν4与ν3的费米共振现象。结果表明ν1振动频率是影响费米共振红外和拉曼光谱特性参数(峰位差Δ,耦合系数W,光谱强度比R,非谐力常数K等)的主要因素,而其光谱强度大小却与这些参数无直接关系。本文用Berttran理论和群论对这一结果给以解释。该研究对理解费米共振现象和分子结构研究中的谱线归属等有参考价值。     

Vacuum-gap-based lumped element Josephson parametric amplifier

We propose a lumped element Josephson parametric amplifier with vacuum-gap-based capacitor.The capacitor is made of quasi-floating aluminum pad and on-chip ground.We take a fabrication process compatible with air-bridge technology,which makes our design adaptable for future on-chip integrated quantum computing system.Further engineering the input impedance,we obtain a gain above 20 dB over 162-MHz bandwidth,along with a quasi quantum-limit noise performance.This work should facilitate the development of quantum information processing and integrated superconducting circuit design.     

粗骨料取代下的高性能再生混凝土率敏性研究

采用分离式霍普金森压杆(SHPB)试验方法对粗骨料取代率为0%、30%、50%和100%的再生混凝土进行冲击试验,研究了应力-应变关系曲线、动态抗压强度、动态弹性模量以及破坏形态受应变率影响的变化规律。试验表明,应力-应变关系曲线开始段呈线性关系,随应变率的增大,线性段斜率增大,持续范围扩大,峰值应力变大;峰值应力具有率敏性,随应变率增大,峰值应力不断增加,取代率对峰值应力的影响差别不明显;动态弹性模量也具有率敏性,呈正相关关系,取代率不同,其率敏性程度有所差异;随着应变率增大,试件破坏程度随之加剧,从完整无裂缝到瞬间崩裂成碎块。     

过量PbO对PLZT（14／0／100）薄膜结构和性能的影响

采用Ｘ射线结构分析方法，对磁控溅射法制备的含过量Ｐｂ０的ＰＬＺＴ（１４／０／１００）薄膜在退火过程中的晶化行为进行了研究。结果表明，薄膜中过量的Ｐｂ０具有促进钙钛矿结构形成、降低晶化温度，并且抑制焦绿石相生长的作用。铁电性能测试结果表明，Ｐｂ０的过量能改善铁电薄膜的耐击穿性，但过量太多的Ｐｂ０会导致薄膜铁电性能变坏。     

2-(1H-1,2,4-三唑-3-基)吡啶MnⅡ配合物的合成、结构及荧光性质

采用水热合成法,通过配体[2-(1H-1,2,4-三唑-3-基)吡啶](2-HTP)与MnSO₄·H₂O中的Mn²⁺离子组装配位,得到一个结构新颖的配合物[Mn(C₇H₅N₄)·(SO₄)·2H₂O](1),对其进行元素分析、红外光谱、X射线单晶衍射、固体荧光以及热重分析等测试。 结构分析表明,配合物1属于单斜晶系P2₁/n空间群,部分晶胞参数:a=1.16373(12) nm,b=0.79324(9) nm,c=1.40241(15) nm,V=1.1996(2) nm³,Z=4。 在配合物1中,配体2-HTP与Mn²⁺离子以双齿的方式配位,Mn²⁺离子还与两个结晶水分子相连并与SO42-中O原子的桥联作用连接成为一维的链状结构。 此外,配体的芳香环之间还存在弱的π-π空间堆积效应,通过对配合物进行固体荧光测试表明其具有良好的蓝光性质,在477 nm处存在较强的荧光发射峰。