On the moments of the time to ruin in dependent Sparre Andersen models with emphasis on Coxian interclaim times

The structural properties of the moments of the time to ruin are studied in dependent Sparre Andersen models. The moments of the time to ruin may be viewed as generalized versions of the Gerber–Shiu function. It is shown that structural properties of the Gerber–Shiu function hold also for the moments of the time to ruin. In particular, the moments continue to satisfy defective renewal equations. These properties are discussed in detail in the model of Willmot and Woo (2012), which has Coxian interclaim times and arbitrary time-dependent claim sizes. Structural quantities needed to determine the moments of the time to ruin are specified under this model. Numerical examples illustrating the methodology are presented.     

茚三酮衍生高效毛细管电泳法测定纯奶中的甘氨酸含量

建立了茚三酮衍生高效毛细管电泳法测定纯奶中甘氨酸含量的方法,该法可选择性测定甘氨酸含量。使用氯化镁为蛋白沉淀剂,沉淀效果较好,研究了甘氨酸–茚三酮聚合物衍生条件,确定最佳实验条件为:未涂层弹性石英毛细管柱(60 cm×75μm,有效长度49 cm),分离缓冲溶液为3.5 mmol磷酸二氢钾–8.2 mmol磷酸氢二钠(pH 6.8),检测波长为570 nm,电泳电压为25 kV,进样压力为25 kPa,进样时间为3 s,电泳温度为室温。甘氨酸的线性范围为2.00~200.00μg/mL,检出限为0.14μg/mL,线性相关系数不小于0.999。甘氨酸的加标回收率为88.7%~107.2%,测定结果的相对标准偏差为2.9%~4.2%(n=6)。该法简便、快速、准确,可用于测定纯奶中甘氨酸含量。     

ASE-SPE/GC-MS/MS同时测定海洋沉积物中71种农药残留

建立了快速溶剂萃取(ASE)-固相萃取(SPE)/气相色谱-三重四极杆串联质谱同时测定海洋沉积物中71种农药残留的方法。结果表明,ASE的最佳萃取条件为:温度100℃,静态时间5 min,循环1次。在此条件下,样品经正己烷-丙酮(1∶1)萃取,石墨化碳柱净化,多离子反应监测(MRM)模式测定,各种农药在1.0~500.0μg·L-1范围内线性关系良好(r2>0.99),方法的检出限(LOD,3σ)为0.29~108.43μg·kg-1。空白样品在100μg·kg-1加标水平下的回收率为51.3%~104.6%,相对标准偏差(n=6)为0.1%~13.5%。应用建立的方法,对实际样品进行分析,共检测出31种农药。     

A PENNY-SHAPED CRACK IN A MAGNETOELECTROELASTIC LAYER UNDER RADIAL SHEAR IMPACT LOADING

This paper analyzes the dynamic magnetoelectroelastic behavior induced by a penny- shaped crack in a magnetoelectroelastic layer.The crack surfaces are subjected to only radial shear impact loading.The Laplace and Hankel transform techniques are employed to reduce the prob- lem to solving a Fredholm integral equation.The dynamic stress intensity factor is obtained and numerically calculated for different layer heights.And the corresponding static solution is given by simple analysis.It is seen that the dynamic stress intensity factor for cracks in a magnetoelec- troelastic layer has the same expression as that in a purely elastic material.And the influences of layer height on both the dynamic and static stress intensity factors are insignificant as h/a>2.     

Joint remote preparation of an arbitrary three-qubit state via EPR-type pairs

In this work, we propose a scheme to realize a joint remote preparation of an arbitrary three-qubit state using six EPR-type pairs as the shared quantum resource. By determining the right measurement bases for the preparers and right ancilla-assisted unitary transformation/recovery operations for the receiver, our scheme applies to the most general case when all the coefficients of the state to be prepared and the EPR-type pairs are complex. The total success probability is found to be dependent only on the “smaller” coefficients of the EPR-type pairs shared between the receiver and one of the preparers.     

基于结构元的复模糊数及其序列极限

复模糊数是模糊复分析中的基本概念,在模糊复分析中,它的运算是基于扩张原理的形式给出的,是对元素遍历某个条件所对应的结果进行运算,这种遍历过程给实际操作带来了很多的不便,因此,在一定程度上也阻碍了模糊复分析理论的应用.对此,本文基于模糊结构元的理论基础,探讨了复模糊数运算的另一种新的途径,这种方法简化了复模糊数的运算,也...     

Powder x-ray diffraction and Rietveld analysis of (C_2H_5NH_3)_2CuCl_4

Structural properties of the organic-inorganic hybrid(C_2H_5NH_3)_2CuCl_4 have been investigated by means of x-ray powder diffraction and Rietveld analysis. A structural phase transition from Pbca to Aba2 occurs at T_4= 240 K, which results in a paraelectric–ferroelectric phase transition. The release of the Jahn–Teller distortion with increasing temperature toward T_4 is revealed by the structural analysis.     

火焰原子吸收光谱法测定鸭粪中铜和锌的含量

采用火焰原子吸收光谱法测定白洋淀生态养鸭场中饲料及鸭粪中的铜和锌含量,测定结果为饲料中的铜含量范围在9.7-61.55mg/kg,锌含量范围在63.14-149.07mg/kg,在禽类饲料中铜、锌含量属于较低的类型;鸭粪中铜含量范围在13.71-94.74mg/kg,锌含量范围在156.98-346.31mg/kg,参...     

Analysis on dependence of phase matching angle on temperature in KDP crystal

The dependence of the phase matching (PM) angle on temperature in type-I second harmonic generation (SHG) and type-II third harmonic generation (THG) of KDP is experimentally investigated. The experimental results show that as the crystal temperatures vary by 1 °C, the external PM angles of the KDP doubler and tripler change 100 μrad and 220 μrad, respectively. The PM angle of KDP tripler is more sensitive to temperature variation than is that of the KDP doubler. Comparing the numerical calculations and the previous reports, a discrepancy has been found among the different reported results. Based on the analytical solution of the temperature dependence of the SHG process it is shown that a small error in the thermo-optic coefficients of the crystal is the main factor source of the discrepancy.     

Temperature-induced metamagnetic transition in ErCo3: influence of Fe and Ni substitutions for Co

The phenomenon of a temperature-induced itinerant metamagnetism in ErCo₃ (at 65 K) was investigated with respect to small substitutions of Fe and Ni for Co. Five percent of Fe or Ni substitutions change the transition temperature to 170 or 25 K, respectively. The transition is accompanied by a large magneto-volume effect, ΔV/V reaches ∼0.5%, which allowed to relate the thermal expansion data with the magnetic state of the d-electrons. The change of the magnetic characteristics with substitutions is mainly ascribed to the shift of the position of the Fermi level in the hybridised d-electron energy band.