Weighted premium calculation principles

A prominent problem in actuarial science is to define, or describe, premium calculation principles (pcp’s) that satisfy certain properties. A frequently used resolution of the problem is achieved via distorting (e.g., lifting) the decumulative distribution function, and then calculating the expectation with respect to it. This leads to coherent pcp’s. Not every pcp can be arrived at in this way. Hence, in this paper we suggest and investigate a broad class of pcp’s, which we call weighted premiums, that are based on weighted loss distributions. Different weight functions lead to different pcp’s: any constant weight function leads to the net premium, an exponential weight function leads to the Esscher premium, and an indicator function leads to the conditional tail expectation. We investigate properties of weighted premiums such as ordering (and in particular loading), invariance. In addition, we derive explicit formulas for weighted premiums for several important classes of loss distributions, thus facilitating parametric statistical inference. We also provide hints and references on non-parametric statistical inferential tools in the area.     

A redox-active two-dimensional coordination polymer: preparation of silver and gold nanoparticles and crystal dynamics on guest removal

A two-dimensional (2D) square-grid coordination polymer, {[Ni(cyclam)]2[BPTC]}n.2nH2O (1), has been assembled from [Ni(cyclam)](ClO4)2 (cyclam = 1,4,8,11-tetraazacyclotetradecane) and H4BPTC (H4BPTC = 1,1'-biphenyl-2,2',6,6'-tetracarboxylic acid) in H2O/MeOH (2.5:1, v/v) in the presence of triethylamine. When solid 1 was immersed in the EtOH solutions of AgNO3 (1.3 x 10(-1) M) and NaAuCl4.2H2O (3.4 x 10(-2) M), respectively, for 5 min at room temperature, solids including Ag (3.7 +/- 0.4 nm, diameter) and Au (2 nm, diameter) nanoparticles were formed by the redox reactions between Ni(II) ions incorporated in 1 and metal ions, as evidenced by HRTEM images, EPR, and XPS spectra. When single-crystal 1 was heated at 180 degrees C under 10(-5) Torr for 24 h, it was transformed to dehydrated compound {[Ni(cyclam)]2[BPTC]}n (2) in the single-crystal-to-single-crystal manner. The X-ray crystal structure of 2 reveals extensive dynamic motions of the molecular components in response to guest removal, involving rotation of the carboxylate and macrocycle, swing of the biphenyl, and bending of the macrocyclic coordination plane toward the carboxylate plane, which reduces the interlayer distance.     

(VO)2P2O7催化剂上正丁烷选择氧化反应路径的原位瞬态DRIFTS研究

在钒磷复合氧化物(VO)2P2O7催化剂上,运用脉冲反应和反应物组成序贯切换的瞬态反应技术,对正丁烷和C4烯烃(1-丁烯、1,3-丁二烯)选择氧化制顺酐过程进行了瞬态原位DRIFTS研究,考察了正丁烷选择氧化反应体系的反应网络和基元过程序列结构。获得了含羰基的非环状饱和与不饱和物种都可能是正丁烷选择氧化制顺酐过程的中间物的证据,在1-丁烯和1,3-丁二烯的原位瞬态DRIFTS研究中检测到了呋喃。推断中间物呋喃在生成顺酐前可能经历了开环形成含羰基的非环状不饱和物种的过程。基于实验结果及与文献的比较,提出了正丁烷在VPO催化剂上选择氧化可能的反应路径。     

Theoretical explorations on the armchair BN nanotube with defects

A systematic study of armchair boron nitride nanotubes (BNNTs) with defects has been carried out within density functional theory. The effect brought by the defects is localized. The defect sites have major contribution to the frontier molecular orbital and change the conductivity of the BNNTs. The defect sites are reactive centers. The substitution of boron with carbon enhances the field emission of the tubes. Doping or vacancy defect creates active center on nanotubes, thus broadening the applications of nanotubes in chemistry and material sciences through functionalization.     

Improving dispersion stability of zirconium hydroxide sol for preparing nano zirconia by the reverse precipitation

Zirconium hydroxide sol was prepared by the reverse precipitation method with ZrOCl₂ solution as raw material and the processing condition of the zirconium hydroxide sol was investigated. When the saturated absorption amount of the surfactant was 1.0?wt%, the pH value for the highest stability was shifted from 7.9 to 9.3 and the pH range for preparing stable zirconium hydroxide sol widened as 8.0-11.0. The suitable concentration of ZrOCl₂ solution for the efficient gelation keeping the high dispersion stability was investigated. The microwave drying was demonstrated to be suitable for preparation of nanoparticle. The characteristics of produced nano zirconia were discussed, which in results the shape of powder was spherical and the grain size was 35?nm at average with moderate dispersion.     

对苯二甲酸邻菲咯啉铽钇配合物的红外光谱及荧光光谱研究

以对苯二甲酸和邻菲咯啉为配体，不同摩尔比铽钇离子为中心体，合成了系列配合物，研究了红外光谱及荧光光谱。结果表明，对苯二甲酸中羧基氧和邻菲咯啉中的氮原子原与稀土离子配位，以邻菲咯啉（Phe)和对苯二甲酸根（L）为配体的配合物（TbxY1-x)2(Phen)2L3中，不发光的Y^3 对发光的Tb^3＋的荧光强强度有明显的增强作用，交联配体对苯二甲比非交联体传递所吸收的能量更加有效。     

Structures and Stability of NHS2 Isomers

Potential energy surface of HNS2 is investigated by means of second-order Moller-Plesset Perturbation theory(MP2) and QCISD(T) (single-point)methods,At final QCISD (T)/6-311 G(3df,2p)//MP2/6-311 G(d,p),level with zero-point vibrational energies included,cis-NHSS is found to be global minimum on the potential energy sufrace,followed by low-lying trans-HNSS ,HN(S)S(C2v).cis-HSNS,cis-NSSN,trans-HSNS,trans-NSSN,and HN(S)S(Cs) by 13.46,66.92,78.25,80.38,81.22,81.38 and 86.40 kJ/mol,respectively.A new high-lying HS(N)S isomer with Cs symmetry is located on the potential energy surface ,The kinetic stabilities of all isomers are predicted.Comprisons are made for HNS2 with its analogues,NHO2,HPS2 and HPO2,The causes that lead to the differences between HNS2 and its analogues are hypervalent capacity of phosphorus and distinct electronegativities of hydrogen,nitrogen and phosphorus.     

氯霉素片中氯霉素含量的HPLC法测定

采用高效液相色谱法测定氯霉素片中氯霉素的含量，用C18柱为分离柱，水-甲醇-冰醋酸（体积比55：45：0.1）为流动相，检测波长278nm，氯霉素进样量在1.6-2.4μg范围内与主峰面积线性关系良好（r=0.9996），平均回收率为101％，重复进样相对标准偏差0.40％（n=7）。