A new ab initio intermolecular potential energy surface and predicted rotational spectra of the Ne-H2S complex

We report a new three-dimensional ab initio intermolecular potential energy surface for the Ne-H(2)S complex with H(2)S monomer fixed at its experimental average structure. Using the supermolecular approach, the intermolecular potential energies were evaluated at CCSD(T) (coupled cluster with single and double and perturbative triple excitations) level with large basis sets including bond functions. The full counterpoise procedure was employed to correct the basis set superposition error. The planar T-shaped global minimum is located at the intermolecular distance of 3.51 ? with a well depth of 71.57 cm(-1). An additional planar local minimum was found to be separated from the global minimum with an energy barrier of 23.11 cm(-1). In addition, two first-order and one second-order saddle points were also located. The combined radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm were employed to evaluate the rovibrational energy levels for eight isotopic species of the Ne-H(2)S complexes. The rotational transition frequencies for the eight isotopomers were also determined for the ground and first vibrational excited states, which are all in very good agreement with the available experimental values.     

Statistical Inferences of Risk Premium under the Generalized Exponential Premium Theory

The principle of exponential premium is an important premium principle in non-life actuarial science. This paper proposes an improved exponential premium principle. This premium principle can not only include the principle of exponential premium as a special case, but also the generalizations of Esscher premium principle and net premium principle, which has many excellent properties as a premium principle. We study the maximal likelihood estimates, nonparametric estimates and Bayesian estimation of risk premium, and discuss the statistical properties including asymptotic unbiased, coincidence, and asymptotic normality. In addition, the asymptotic confidence interval for this risk premium is given. Finally, the convergence rate of maximum likelihood estimation and nonparametric estimation is compared by numerical simulation method. The results show that the nonparametric estimation has a small mean square error when the sample size is small.     

磷腈-紫精聚合物的合成与电致变色性能

以六氯环三磷腈作为核心、 紫精为电致变色活性基, 合成了一种新型有机-无机杂化电致变色材料——六(1-乙基-4,4'-联吡啶-甲基苯氧基)环三磷腈(PHV ²⁺). 通过傅里叶变换红外光谱(FTIR)、 X射线衍射(XRD)及核磁共振氢谱( ¹H NMR)表征了PHV ²⁺的结构. 优良的水溶性使得该化合物可以通过简单的方法构造一个以聚乙烯醇(PVA)为凝胶基质的电致变色水凝胶, 具有成本低廉及无毒害的优点. 以氟掺杂氧化锡(FTO)涂层玻璃作为电极材料, PHV ²⁺作为电致变色材料制备了PHV ²⁺/PVA/KCl电致变色器件(PHV ²⁺/PVA/KCl ECD). 该电致变色器件在2.1 V电压下由淡黄色变为紫色, 颜色变化明显, 并且该颜色变化可以循环500次; 器件在526 nm处的光学对比度达到62.19%. 良好的电致变色性质使该化合物在电致变色器件方面具有潜在应用价值.     

超高效液相色谱-四极杆-飞行时间高分辨质谱用于乳液类化妆品中9种抗过敏违禁药物的筛查和定量分析

建立了超高效液相色谱-四极杆-飞行时间高分辨质谱(UPLC-Q-TOF-HRMS)快速筛查和定量检测乳液类化妆品中9种抗过敏违禁药物的方法。乳液样品经乙腈涡旋和超声提取,采用PRiME HLB固相萃取小柱净化,以0.1%甲酸水-乙腈为流动相在XBridge C18色谱柱上进行梯度洗脱和分离,采用电喷雾电离源,在正离子模式下采用全景式数据非依赖性扫描模式(SWATH)进行数据采集,结合保留时间、母离子精确质量数、同位素峰及二级子离子碎片进行快速定性筛查,采用特征子离子碎片的峰面积进行外标法定量。实验比较了不同仪器条件和前处理条件对乳液类样品中9种抗过敏物质测定的影响,并对比了不同级别离子定量对基质效应的影响。结果表明,较其他净化柱而言,PRiME HLB固相萃取小柱具有更好的净化效果,能降低杂质对目标峰的干扰,同时保证目标物的回收;在优化的条件下,9种抗过敏药物在5~100 μg/L质量浓度范围内线性良好,相关系数(r²)均大于0.99; 9种目标物的定量限在0.05~0.10 mg/kg之间;在3个添加水平(0.10、0.20和0.60 mg/kg)下,其回收率在65.3%~107%之间,相对标准偏差(RSD, n=6)均小于20%;基质效应实验结果表明,采用二级子离子定量能够降低基质效应,提高定量准确度。与文献方法相比,该法操作简便,前处理耗时更短,其高精度质量数和二级指纹图谱比对技术能保证检测结果的准确度和灵敏度,可实现乳液类化妆品中抗过敏违禁药物的快速筛查和准确定量。     

����ָ������ԭ���з��ձ��ѵ�ͳ���ƶ�

??The principle of exponential premium is an important premium principle in non-life actuarial science. This paper proposes an improved exponential premium principle. This premium principle can not only include the principle of exponential premium as a special case, but also the generalizations of Esscher premium principle and net premium principle, which has many excellent properties as a premium principle. We study the maximal likelihood estimates, nonparametric estimates and Bayesian estimation of risk premium, and discuss the statistical properties including asymptotic unbiased, coincidence, and asymptotic normality. In addition, the asymptotic confidence interval for this risk premium is given. Finally, the convergence rate of maximum likelihood estimation and nonparametric estimation is compared by numerical simulation method. The results show that the nonparametric estimation has a small mean square error when the sample size is small.     

Voltammetric detection of guanosine and adenosine using a carbon paste electrode modified with 1-ethyl-3-methylimidazolium ethylsulfate

A novel kind of carbon paste electrode (CPE) was prepared by mixing graphite powder, liquid paraffin and the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate. The resulting electrode was used for the simultaneous determination of guanosine and adenosine by differential pulse voltammetry. Compared to a conventional CPE, the oxidation peak currents are largely increased, and the oxidation peak potentials are negatively shifted. The electrochemical responses to guanosine and adenosine were investigated. Under optimized conditions, the calibration curves are linear in the concentration range from 1.0?×?10^-6?mol?L^-1 to 1.6?×?10^-4?mol?L^-1 for guanosine, and from 1.0?×?10^-6?mol?L^-1 to 2.7?×?10^-4?mol?L^-1 for adenosine at pH 3.5. Substances potentially interfering in the biological matrix do no interfere. The method was successfully applied to detect adenosine and guanosine in human urine without sample treatments.

Cationic Chalcogenoviologen Derivatives for Photodynamic Antimicrobial Therapy and Skin Regeneration

A series of water-soluble cationic chalcogenoviologen-based photosensitizers for photodynamic antimicrobial therapy (PDAT) is reported. The Se-containing derivatives (SeMV²⁺) 5 b and 6 b showed good antimicrobial activities due to the presence of chalcogen atoms and a cationic scaffold. The former efficiently enhanced the generation of reactive oxygen species (ROS), and the latter facilitated the ROS delivery to bacteria, resulting in their death. Interestingly, alkyl-modified photosensitizers showed higher antimicrobial activities than commonly reported photosensitizers with quaternary ammonium (QA) groups. In particular, the SeMV²⁺ ( 6 b ) with excellent antibacterial activities efficiently promoted the healing of infected wounds in mice. Simple yet novel, nontoxic and biocompatible chalcogenoviologens provided a promising strategy to develop new efficient photosensitizers for photodynamic antimicrobial therapy and skin regeneration.     

Studies on Intestinal Transport of Ginsenoside Compatibility with Veratrum nigrum via Caco-2 Cell Monolayer Model Coupled with UPLC-ESI-MS Method

The Caco-2 cells have been recognized as effective tools to be applied to imitating the drug absorption in human intestine for the transport of drug. Herein, Caco-2 cell monolayer model was used to study the transport of the ginsenoside compatibility with Veratrum nigrum in different proportions. A specific high performance liquid chromatography-electrospray ionization-mass spectrometry(HPLC-ESI-MS) method was developed for the semiquantitative determination of ginsenoside in intestinal transport with Dioscin as an internal standard. For the Caco-2 model constructed, two influencing factors were investigated, including time and concentration. The results suggest that the absorption of ginsenoside Re, Rg1, Rb1, Rc, Rb2 and Rd are time- and concentration-dependent and the excretions of Rb1, Rc, Rb2 and Rd have a relatronship with some transport proteins. The bioavailability of the ginsenosides has reduced compared to the single Panax ginseng extract when compatibility with a certain amount of Veratrum nigrum.     

Determination of 3, 4-dihydroxybenzoic acid by electrocatalytic oxidation at an ionic liquid modified electrode

An electrode modified with an ionic liquid was used for the electrochemical determination of 3,4-dihydroxybenzoic acid (DHBA). Cyclic voltammetry indicated a pair of well-defined quasi-reversible redox peaks with a formal peak potential located at 586 mV (vs. the SCE). The voltammetric response to DHBA is largely improved compared to a traditional carbon paste electrode. This is attributed to a larger interface (due to the presence of an ionic liquid) with higher conductivity and inherent catalytic capability. The charge transfer coefficient, the standard rate constant and the apparent diffusion coefficient were calculated. The oxidation peak current was linearly related to the concentration of DHBA in the range 0.8–1.5 mM, and the detection limit was 0.62 µM (at 3σ). The effect of potential interferents was investigated, and the method was successfully applied to the determination of DHBA in different samples.

     

Range of Validity of a Simplified Model for Diffuse Charge Dynamics

The modelling of electrochemical processes often requires the solution of the Poisson‐Nernst‐Planck (PNP) equations. In complex geometries, such as porous electrodes, that is challenging due to the presence of disparate length scales, ranging from the Debye screening length (～nm) to the device length scale (～cm). To overcome this difficulty, one often assumes that the electric double layer (EDL) is at quasi‐equilibrium to construct a simplified model that accounts for ion diffusion in the electro‐neutral bulk of the electrolyte while replacing the EDLs with appropriate boundary conditions. Various researchers have demonstrated that such an approach is valid in the asymptotic limit of a thin EDL and moderate electrode potentials. In this note, we explore the range of validity of this approximation by considering a one‐dimensional electrolytic cell with blocking electrodes subjected to a step change and time‐periodic alternations in the electrodes’ potentials by calculating the errors associated with the approximate approach as functions of the EDL thickness and electric field frequency and intensity. Additionally, we delineate numerical instabilities associated with the numerical solutions of the bulk equations with the nonlinear boundary condition peculiar to this problem.