反式阿魏酸钌配合物的合成、表征、荧光光谱及其与DNA/蛋白作用

对天然产物反式阿魏酸进行化学修饰,设计、合成了2种单核钌配合物[Ru(cym)(L)Cl]Cl (Ru-1)与[Ru(bpy)2(L)]Cl2(Ru-2)(cym=对伞花烃,bpy=2,2′-联吡啶,L=(E)-3-(4-hydroxy-3-methoxyphenyl)-N-((4′-methyl-(2,2′-bipyridin)-4-yl)methyl)acrylamide),通过核磁共振氢谱和碳谱、电喷雾质谱对配合物进行了结构表征。利用荧光、紫外-可见光谱等方法研究了配合物的溶解性和光学性质。配合物均具有良好的亲水性。Ru-2有良好的荧光性能,其发射波长达到近红外的631 nm,且可以在pH值为8～10之间实现响应。Ru-2还具有较高的单线态氧量子产率(Φ=0.70),有望成为一类高效的光敏剂。2种配合物都与CT-DNA发生嵌入作用(Kb分别为1.210×104和1.233×103L·mol-1);均与BSA有一个结合位点,使其荧光发生静态淬灭(Ka值分别为1.94×104,2.45×104)。     

Contribution of CuxO distribution,shape and ratio on TiO2 nanotubes to improve methanol production from CO2 photoelectroreduction

Many studies are focused on the development of materials for converting carbon dioxide into multicarbon oxygenates such as methanol and ethanol, because of their higher energy density and wider applicability. In this work, TiO₂ nanotubes (NT/TiO₂) were modified with Cu_xO nanoparticles in order to investigate the contribution of different ratio of Cu₂O/CuO and its distribution over NT/TiO₂ for CO₂ photoelectro-conversion to methanol. The photoelectrodes were built by anodization process to obtain NT/TiO₂ layer, and the decoration with Cu_xO hybrid system was carried out by electrodeposition process, using Na₂SO₄ or acid lactic as electrolyte, followed by annealing at different temperatures. X-ray photoelectron spectroscopy analysis revealed the predominance of Cu⁺¹ and Cu⁺² at 150 °C and 300 °C, respectively. X-ray diffraction and scanning electron microscopy indicated that under lactic acid solution, the oxide nanoparticles exhibited small size, cubic shape, and uniform distribution on the nanotube wall. While under Na₂SO₄ electrolyte, large nanoparticles with two different morphologies, octahedral and cubic shapes, were deposited on the top of the nanotubes. All modified electrodes converted CO₂ in methanol in different quantities, identified by gas chromatograph. However, the NT/TiO₂ modified with CuO/Cu₂O (80:20) nanoparticles using lactic acid as electrolyte showed better performance in the CO₂ reduction to methanol (0.11 mmol L⁻¹) in relation to the other electrodes. In all cases, a blend among the structures and nanoparticle morphologies were achieved and essential to create new site of reactions what improved the use of light irradiation, minimization of charge recombination rate and promoted high selectivity of products.

     

Modified electrode with reduced graphene oxide/poly(3-hydroxyphenylacetic acid): a new platform for oligonucleotide hybridization

Journal of Solid State Electrochemistry - This paper reports a new platform for oligonucleotide hybridization, prepared by electropolymerization of 3-hydroxyphenylacetic acid onto gold electrode...     

All Pure Two-Qudit Entangled States Generated via a Universal Yang-Baxter Matrix Assisted by Local Unitary Transformations

We show that all pure entangled states of two d-dimensional quantum systems （i.e., two qudits） can be generated from an initial separable state via a universal Yang-Baxter matrix if one is assisted by local unitary transformations.     

基于自相关函数的激光散斑统计半径的测量

为了测量激光散斑的统计半径,运用统计光学理论推导了二维近场散斑光强的归一化自相关函数,并提出了通过求解散斑图像自相关拟合函数的系数来计算激光散斑统计半径的一种测量方法,利用该测量方法编制的测量软件可以方便地计算出激光散斑的统计半径.通过对尺寸已知的模拟散斑的测量,测量结果与实际尺寸相吻合,证实了该测量方法的可行性.     

钝体后湍流预混燃烧的PDF模拟

本文采用PDF方法对矩形燃烧室内钝体后的湍流预混火焰进行了数值模拟。脉动速度-频率-标量联合的PDF输运方程用Monte Carlo方法求解,质量、动量和能量的平均值由基于无结构网格的有限体积法求解,压力通过状态方程获得。PDF方程中所需的平均密度、平均速度和压力由有限体积法提供,并将用Monte Carlo方法求出的雷诺应力、化学反应源项和比热比传递给有限体积法。本文对丙烷和空气燃烧的不同简化化学反应机理进行了研究,并与实验结果进行比较,获得满意的结果。     

Byte structure variable length coding (BS-VLC): a new specific algorithm applied in the compression of trajectories generated by molecular dynamics

Molecular dynamics is a well-known technique very much used in the study of biomolecular systems. The trajectory files produced by molecular dynamics simulations are extensive, and the classical lossless algorithms give poor efficiencies in their compression. In this work, a new specific algorithm, named byte structure variable length coding (BS-VLC), is introduced. Trajectory files, obtained by molecular dynamics applied to trypsin and a trypsin:pancreatic trypsin inhibitor complex, were compressed using four classical lossless algorithms (Huffman, adaptive Huffman, LZW, and LZ77) as well as the BS-VLC algorithm. The results obtained show that BS-VLC nearly triplicates the compression efficiency of the best classical lossless algorithm, preserving a near lossless behavior. Compression efficiencies close to 50% can be obtained with a high degree of precision, and the maximum efficiency possible (75%), within this algorithm, can be performed with good precision.     

Observation of a continuum-continuum interference hole in ultrafast dissociating core-excited molecules

The femtosecond dissociation of HCl after core excitation has been studied through the resonant Auger decay. The spectra contain contributions from decay occurring at both "molecular" and "atomic" internuclear distances. We have observed a new interference mechanism in these spectra: An atomic spectral line develops into a negative spectral contribution, a "hole," when detuning the excitation energy from the maximum of the Cl2p(-1)sigma(*) resonance. Resonant x-ray scattering theory quantitatively explains this behavior as due to a novel destructive continuum-continuum interference between molecular and atomic contributions to the Auger decay.     

非结构子网格压力方法

纯拉氏流体力学计算失败的根源是砂漏运动和虚假涡旋,运用子网格拉氏质量与其相关的子网格密度得到子网格压力,子网格压力产生的扰动隅角力能消除这些虚假运动,以便消除困扰拉氏流体力学算法的网格畸变带来的数值计算困难.将包括子网格压力的相容流体算法推广到非结构网格,研制包括非结构子网格压力的相容流体程序,对Saltzman活塞问题进行数值模拟,从数值结果分析可知,非结构子网格压力方法能抑制虚假涡旋,消除砂漏畸变.