N-fold generalized Darboux transformation and breather–rogue waves on the constant/periodic background for a generalized mixed nonlinear Schrödinger equation

Nonlinear Dynamics - In this paper, a generalized mixed nonlinear Schrödinger equation, which arises in several physical applications including fluid mechanics (for the weakly nonlinear...     

Novel lead(II) carboxylate-arsonate hybrids

Hydrothermal reactions of lead(II) acetate with phenylarsonic acid (H₂L¹) (or 4-hydroxy-3-nitrophenylarsonic acid, H₃L²) and 5-sulfoisophthalic acid monosodium salt (NaH₂SIP) (or 1,3,5-benzenetricarboxylic acid (H₃BTC)) as the second metal linkers afforded three novel mixed-ligand lead(II) carboxylate-arsonates, namely, Pb₅(SIP)₂(L¹)₂(H₂O) 1, Pb₃(SIP)(L²)(H₂O) 2 and Pb(H₂L²)(H₂BTC) 3. The structure of 1 features a complicated 3D network composed of 2D double layers of lead(II) sulfoisophthalate bridged by 1D chains of lead(II) arsonates along b-axis, forming large tunnels along b-axis which are occupied by phenyl rings of the arsonate ligands. In 2, the Pb(II) ions are bridged by {L²}³⁻ anions into a 2D double layer whereas the interconnection of the Pb(II) ions via bridging and chelating SIP anions gave a 2D double layer. The cross-linkage of the above two building units leads to a complicated 3D network. In 3, the interconnection of the Pb(II) ions via bridging {H₂L²}⁻ and {H₂BTC}⁻ anions leads to a 1D double chain down a-axis. These 1D chains are further interconnected via hydrogen bonds among non-coordination carboxylate groups and arsonate oxygens into a 3D supramolecular architecture.     

Two new coordination polymers based on tartaric acid ligand: Syntheses,crystal structure and thermal stability

Two new coordination polymers [Cd₃(D-Tar)₃]_n (1) and [Pb(meso-Tar)]_n (2) (H₂Tar = tartaric acid) have been synthesized by hydrothermal reaction and characterized by single crystal X-ray diffraction analysis and IR spectra. 1 crystallizes in the C222₁ chiral space group and shows a 3D (4,4)-connected net with the (4.6.8⁴)₄(4.6².8².10)(4.6².8³)(4.6³.8²)(4.6³.8²)₄(4.8⁵)₂ topology. 2 possesses a 3D (4,4)-connected net with the (4³.6².8) topology. In addition, the thermogravimetric analyses (TGA) results for polymers are discussed.     

Interaction of a New Fluorescent Probe with DNA and its Use in Determination of DNA

In this paper we reported a metal complex 1-Zn (2,5-di-[2-(3,5-bis(2-pyridylmethyl)amine-4-hydroxy-phenyl)-ethylene]-pyrazine-Zn) as a fluorescent probe sensing DNA. The result of the competitive experiment of the probe with ethidium bromide (EB) to bind DNA, absorption spectral change and polarization change in the presence and absence of DNA revealed that interaction between the probe and DNA was via intercalation. Ionic strength experiment showed the existence of electrostatic interaction as well. Scatchard plots also confirmed the combined binding modes. The fluorescence enhancement of the probe was ascribed to highly hydrophobic environment when it bound the macromolecules such as DNA, RNA or denatured DNA. The binding constant between the probe and DNA was estimated as 3.13 × 10⁷ mol⁻¹ L. The emission intensity increase was proportional to the concentration of DNA. Based on this, the probe was used to determine the concentration of calf thymus DNA (ct-DNA). The corresponding linear response ranged from 2.50 × 10⁻⁷ to 4.75 × 10⁻⁶ mol L⁻¹, and detection limit was 1.93 × 10⁻⁸ mol L⁻¹ for ct-DNA.     

以5-(6-羧酸-2-萘基)-间苯二羧酸为配体构筑的两个镉的金属-有机骨架化合物的合成、晶体结构及荧光性质

在溶剂热条件下,以不对称三羧酸5-（6-羧酸-2-萘基）-间苯二羧酸（H3L）为配体合成了2个镉的金属-有机骨架化合物:{[Cd₃L₂（H₂O）₃]·6DMF}_n（1）和{[Cd₃L₂（H₂O）₄]·3DMA}_n（2）。通过X射线单晶衍射,粉末衍射,热重和红外光谱进行了结构表征。结构分析表明,1和2形成3,6-连接的三维结构,其拓扑符号分别为:（4⁵.6⁴.8⁶）（4³）₂和(6¹².8³)（6³）₂。此外,还对2个化合物进行了荧光分析。     

超短脉冲抽运下频率一致纠缠光源量子特性实验研究

利用自发参量下转换过程产生的频率纠缠光源在量子信息处理及相关领域中 具有十分重要的应用. 本文利用中心波长为792 nm, 脉冲宽度小于20 fs的脉冲激光源抽运满足II类准相位 匹配条件的周期极化磷酸氧钛钾晶体, 实验产生了偏振相互正交的频率一致纠缠光子对. 基于Hong-Ou-Mandel干涉仪的二阶量子符合干涉装置, 测量到该纠缠双光子对的干涉可见度约为42%, 表明其频率不可分特性较理想频率一致纠缠光源大大降低. 通过理论分析给出, 由于超短脉冲光源对应的宽频谱带宽影响, 相位匹配函数中的高阶色散项不再忽略, 从而导致纠缠光子对的频率不可分性减弱. 进一步利用实验参数给出的数值模拟结果与实验结果符合, 证实了脉冲抽运源带宽对频率一致纠缠光源的量子不可分特性的影响.关键词：频率一致纠缠Hong-Ou-Mandel干涉测量符合计数     

ADT-Type [FeFe]-hydrogenase biomimics featuring monodentate phosphines: formation,structures, and electrocatalysis

Transition Metal Chemistry - To further develop the diiron subsite biomimics of [FeFe]-hydrogenases, two new diiron azadithiolate (adt) complexes Fe2(μ-adtNPh)(CO)5(Ph2PX)...     

利用共振无源腔分析和抑制飞秒脉冲激光噪声的理论和实验研究

理论分析了共振无源腔对飞秒脉冲激光的强度和相位噪声的转化模型,分析表明,通过测量无源腔透射场或者反射场相对于输入场强度噪声的变化,可以间接得到输入场飞秒脉冲激光的相位噪声.在此基础上设计了精细度约为1500、自由光谱区为75 MHz的八镜环形共振无源腔,并测量了钛宝石锁模激光经过该共振无源腔后透射场和反射场强度噪声的变化.实验观察到,飞秒脉冲激光经过无源腔透射后,强度噪声特性得到较好改善,在探测频率2 MHz附近达到散粒噪声极限.同时,结合共振无源腔对激光强度和相位噪声的转化模型,间接给出了钛宝石锁模激光的相位噪声及无源腔对相位噪声的有效抑制作用.