An empirical study on operational diversification and performance of China′s property insurance companies

本文对我国财产保险公司1999年~2005年多元化经营与绩效之间的关系进行实证研究。通过多元回归模型分析,我们发现,财险公司产品多元化与公司绩效有着非线性关系,经营区域多元化对公司绩效有显著正向影响。同时,财险公司产品多元化与经营区域多元化之间存在交互关系,并对公司绩效有负向影响,产品多元化经营是否能提高公司绩效因其经营区域多元化程度的不同而不同。实证结果还显示,公司规模和集团化对财险公司绩效有显著的正向影响,而投资资产比例与财险公司绩效没有显著的影响关系。This paper investigated the relationship between operational diversification and performance of property insurance companies in China during the period of 1999-2005.Our empirical analyses showed that there was a nonlinear relationship between product diversification and insurer′s performance;and geographic diversification had a positive effect on overall performance.Moreover,there was an interactive relationship between product diversification and geographic diversification and had a negative effect on insurer′s performance.Whether product diversification could enhance performance varied with the degree of geographic diversification.The empirical results also indicated that the firm size and group status were positively related to insurer′s financial performance,while the ratio of investment assets had no visible impact on the performance of property insurance companies.国家社会科学基金项目(06BJY005);福建省社会科学规划项目(2006B2135

小麦株高遗传解析

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高密度遗传连锁图谱对小麦基因定位克隆、分子育种及基因组学研究至关重要。多种分子标记被成功应用于小麦遗传图谱的构建,基于不同作图群体已释放40余个版本小麦遗传图谱,以高密度遗传图谱为桥梁,实现上述遗传图谱的整合将为分子育种奠定重要的遗传资源。本研究利用小麦科农9204×京411构建的重组自交系KJ-RIL群体及660K小麦基因组芯片(Affymetrix Wheat660 chip),绘制了包含119566个位点的小麦高密度遗传连锁图谱,图谱总长度4424.4cM,标记间平均距离为0.04cM/位点。经比较分析,该高密度遗传图谱与90K、820K高密度整合图谱及小麦基因组物理图谱均具有较好的共线性对应关系。结合前人已报道遗传图谱及其标记序列信息,以660K芯片高密度遗传连锁图谱为骨架,梳理AFLP、RFLP、RAPD、SSR、EST-SSR、STS、SRAP、DarT、SNP等标记遗传位置及基因组序列信息,构建了小麦高密度一致性整合图谱。结合表型数据、高密度遗传图谱极其基因型值,对控制穗粒数主效QTL-qKnps-4A、株高主效QTL-qPh-6B等多个QTL进行了精准定位,绘制了靶区段高密度遗传连锁图谱,该结果为靶基因的精细定位及图位克隆奠定基础

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该项目对新增的声波成向测井和长源距声波测井两种方法，在碳酸盐岩裂缝储层研究中的应用进行了研究。其开发了一套多功能全波数据格式转换和波形显示程序，能够实现阿特拉斯公司和哈里伯顿公司数据的读取，及哈里伯顿格式到阿特拉斯公司的转换；根据纵波和横波时差可计算一个新的裂缝指标FI，同时根据纵波时差变化率提供了另一个裂缝指标，进一步改进了综合概率模型；根据23口井的声波成象测井处理结果，优选出了80个样本对常用的三种裂缝指标进行了标定，同时出一个缝洞孔隙指数；根据现有各井成象测井提取的裂缝密度、裂缝倾角和倾向信息，对区域裂缝的空间分布进行了分析，对进一步勘探开发有利地段提出了预测

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies