高效液相色谱检测Zn（Ⅱ）、Cd（Ⅱ）、Co（Ⅱ）、Pb（Ⅱ）、Ni（Ⅱ）、Cu（Ⅱ）、Hg（Ⅱ）

用双-(2-羟乙基)二硫代甲酸铵(HEDC)在反相液相色谱中作检测某些金属离子的衍生化试剂，HEDC的金属螯合物微溶于水，可直接水样注射于C18柱中进行检测，范围为0．006～10mg／L相对偏差1％～2％，检测波长254nm，金属汞的整合物在HPLC分析前进行浓缩富集检测限可低至0．06～25μg／L，相对偏差小于2％。     

Universal scheme for finite-probability perfect transfer of arbitrary multispin states through spin chains

In combination with the theories of open system and quantum recovering measurement, we propose a quantum state transfer scheme using spin chains by performing two sequential operations: a projective measurement on the spins of ‘environment’ followed by suitably designed quantum recovering measurements on the spins of interest. The scheme allows perfect transfer of arbitrary multispin states through multiple parallel spin chains with finite probability. Our scheme is universal in the sense that it is state-independent and applicable to any model possessing spin–spin interactions. We also present possible methods to implement the required measurements taking into account the current experimental technologies. As applications, we consider two typical models for which the probabilities of perfect state transfer are found to be reasonably high at optimally chosen moments during the time evolution.     

Quantum interference induced by initial system–environment correlations

We investigate the quantum interference induced by a relative phase in the correlated initial state of a system which consists in a two-level atom interacting with a damped mode of the radiation field. We show that the initial relative phase has significant effects on both the evolution of the atomic excited-state population and the information flow between the atom and the reservoir, as quantified by the trace distance. Furthermore, by considering two two-level atoms interacting with a common damped mode of the radiation field, we highlight how initial relative phases can affect the subsequent entanglement dynamics.     

Preparation of Pt–CeO2/MWNT nano-composites by reverse micellar method for methanol oxidation

We report the preparation of Pt–CeO₂ nanoparticles on the multi-walled carbon nanotubes (MWNTs) by a reverse micellar method. Transmission electron microscopy (TEM) analysis indicated that well-dispersed small Pt–CeO₂ nanoparticles were formed on the MWCNTs. X-ray diffraction (XRD) analysis confirmed the formation of the Pt–CeO₂ nanoparticles on the MWNTs. Cyclic voltammetry (CV) results demonstrated that the Pt–CeO₂/MWNT exhibited a higher methanol oxidation than did the Pt/MWNT catalyst. The CO stripping test showed that CeO₂ can make CO stripped at a lower potential, which is helpful for CO and methanol electro-oxidation.     

Coupling matrix element of electron self-exchange reactions in solution

On the basis of the common feature among the electron transfer process and the ion hydration process as well as the relevant experimental kinetic data of electron transfer reaction,a new accurate hydration potential function scheme for the determination of electron transfer coupling matrix element is presented.The coupling matrix element between two hydrated ions of the reacting system in solution is calculated.The results and the applicability of this scheme are discussed.     

2-[2-(7H-二苯并[a,g]咔唑)-乙氧基]-乙基氯甲酸酯对脂肪胺类化合物的荧光标记及质谱鉴定

利用新型荧光标记试剂2-[2-(7H-二苯并[a,g]咔唑-乙氧基)-乙基氯甲酸酯作为柱前衍生化试剂, 在Eclipse XDB-C8反相色谱柱上,采用梯度洗脱,实现了12种脂肪胺类化合物完全基线分离.检测最佳激发和发射波长分别为300和400 nm.通过荧光检测及离子阱大气压化学电离源(APCI Source)正离子模式实现了在线的柱后质谱鉴定.对土壤中脂肪胺类化合物的测定快速、准确,具有良好的重现性.荧光定量检测的回归系数大于0.9991; 检出限为10.1～0.3 fmol.     

Microcalorimetric Studies on the CMC and Thermodynamic Functions of a Nonionic Surfactant (Tween80) in DMF/Long-Chain Alcohol Systems from <Emphasis Type="Italic">T</Emphasis>=298.15 to <Emphasis Type="Italic">T</Emphasis>=313.15 K

The power-time curves of the micelle formation process were determined for the nonionic surfactant Tween80/nonaqueous solvent (DMF)/long-chain alcohol (n-heptanol, n-octanol, n-nonanol, and n-decanol) systems by titration microcalorimetry at temperatures of (298.15, 303.15, 308.15, and 313.15) K. From the power-time curves, the CMC and DH_m^\uptheta\Delta H_{\mathrm{m}}^{\uptheta} values were obtained. The corresponding values of DG_m^\uptheta\Delta G_{\mathrm{m}}^{\uptheta} and DS_m^\uptheta\Delta S_{\mathrm{m}}^{\uptheta} were also calculated. The relationships of the CMC with the carbon number of the alcohol, the concentration of alcohol, and the temperature, along with the thermodynamic functions, are discussed.     

A DFT study on the effect of hydrogen bonding on the reaction of a μ-benzoquinone diruthenium complex with acetylene

A DFT study was carried out to investigate the reaction mechanisms of a model μ-benzoquinone diruthenium complex {CpRu(μ-H)}₂(μ-η²:η²-C₆H₄O₂), derived from the experimental compound {Cp*Ru(μ-H)}₂(μ-η²:η²-C₆H₃RO₂) (R = H or R = Me, Cp* = η⁵-C₅Me₅), with acetylene both in aprotic and protic solvents. Results of calculations show that the influence of the solvent methanol on the reaction is mainly on the step of acetylene coordination. Enhanced hydrogen bonding is the reason for acceleration of the reaction in protic solvent, which is supported by NBO charge analysis.