1961～2005年漠河年均温和年均高低温的变化分析

对近四十五年来中国漠河的气温变化作了一个初步分析.根据中国漠河1961～2005年逐日平均、最高、最低气温资料,求得了相应的年均温、年均高温和年均低温,分别对它们进行了线性拟合,结果表明它们在这45年都有所升高,并且由t检验得出线性趋势都是显著的.之后用线性回归模型拟合了年均温与年均高温和年均低温的关系,得出了拟合方程,并由F检验说明了线性回归关系的显著性.最后又采用变系数回归模型的局部线性拟合方法拟合了年均温与年均高温和年均低温的变化关系,从而揭示了年均高温和年均低温对年均温的影响随时间变化的规律,对研究年均温升高的原因具有一定的参考意义.     

会计盈余的均值回复、年度审计效应和跨年效应

多种盈余管理动机的复合效应是产生盈余平滑。本文基于此认为稳定的盈余管理目标促使管理层选择盈余平滑策略,该论断可通过建立会计盈余的均值回复模型来验证。盈余管理策略也促发了对应计项的调整,该论断可通过建立一个简化的现金流盈余反应模型来验证。基于该简化模型可从盈余管理中分解出年度审计效应(实质来源于短期盈余管理行为)和跨年效应(实质来源于长期盈余管理行为)。实证部分对报告的会计盈余的均值回复性、盈余管理的年度审计效应和跨年效应进行了检验,检验结果表明公司管理层有比较稳定的盈余管理目标,并在非年报季度有较强的盈余管理行为,而年内盈余管理效应异于跨年盈余管理效应。实证结论符合理论预期。     

考虑死亡风险下权益指数年金的定价

权益指数年金(Equity Indexed Annuities)是欧美市场近十年发展起来的一类新型年金产品,有最小收益保证,在最小保证基础上与预先设定好的某类股指收益相关联．本文在考虑死亡风险情况下,对简单点对点和年度重设两种指数计算方法下权益指数年金的定价问题作了研究,给出了定价公式并对参与率作了敏感性分析．     

信息安全风险模型

基于决策分析技术,提出了一种决策驱动的风险管理模型框架,并给出了安全策略纯效益的算法,该模型与目前国内流行的风险模型相比,能定量的分析风险管理,给出有害事件爆发频率和影响程度的具体缩减值以及计算出每个安全策略的纯效益,得到最佳安全策略.     

非重子冷暗物质粒子的研究进展

暗物质问题目前已受到物理学界的高度关注，因为这一课题的研究和进展，将直接影响到粒子物理、天体物理和宇宙学的发展方向。当前世界上已有一些大的实验组正在开展这方面的研究工作，并已取得了一定的结果；文章重点介绍两个重要的探测实验，即中意合作DAMA组（Dark Matter Group)100kg Nal（Tl）探测器阵列实验和美国的CDMS（Cold Dark Matter Search）实验组的低温探测器实验。详细介绍了DAMA实验的物理分析方法及其实验结果，并同CDMS实验结果进行了相应的比较。     

Indoor radon measurement in Izmir Province,Turkey

In 2013, an extensive study was performed in a total of 117 locations in Izmir province and indoor radon levels were measured using the alpha track etch integrated method with LR-115 detectors. As the maps are more practical to interpret the results of radiological survey, the distributions of indoor ²²²Rn activities in four most densely populated districts of Izmir were mapped in detail. It is seen that the estimated average radon concentration level (210 Bq m^?3) determined in Izmir province was almost three times higher than the mean value for Turkey (81 Bq m^?3). Exposed annual effective dose equivalents for Izmir province were estimated in the range of 0.7 to 12.3 mSv year^?1 with a mean of 5.3 mSv year^?1. In this study, it is pointed out that indoor radon concentration was affected by the age of the building and height above the ground.     

Correlation Analysis of the Runoff of the Rivers and the Seisms in China

In recent hundred years the annual discharge variations of the Changjiang River (represented by the Yichang station) and the Huanghe River (represented by Shanxian and Tangnaihe, respectively) have closely related to the geographical distribution of the earthquakes coming about in China in the same year, Both the occurrence of the destructive seism or seismic swarm in the river basins and the disappearance of the shocks in the east and south of the basins are the conditions that the Changjiang and Huanghe Rivers are the high flow while that the strong earthquake of magnitude 7 or more occurred in North China is the condition for the Changjiang low flow year and that of 6 or more in the Qilian Mountains area is for the Huanghe River. In the latter part of this paper, a 2-year sample is given to explain that the conditions of the 2 rivers being high flow years are that the north-south seismic belt is active and in the meanwhile no seism occurred in South China, and those of the low flow year are that the     

燃气机热泵全年性能优化研究

本文建立了燃气机热泵(GEHP)的全年性能优化模型,定义了燃气机热泵的全年性能系数,比较了采用不同优化目标函数得到的优化结果的差别,研究了冷负荷比例变化对全年性能优化的影响,分析了燃气机热泵在不同地区应用时全年性能优化目标的确定.     

The determination of concentrations of radioisotopes in some granite samples in Turkey and their radiation hazards

The primordial radionuclides activity concentrations (²²⁶Ra, ⁴⁰K and ²³²Th) are measured in some granite samples in this study. The collected granite materials are analyzed with NaI(Tl) gamma-ray spectrometry. The specific activity of ²²⁶Ra, ²³²Th and ⁴⁰K values are in range 2.60?±?0.10 to 178.9?±?0.6?Bq?kg^?1, 1.46?±?0.10 to 162.50?±?0.75?Bq?kg^?1 and 19.8?±?0.3 to 579.7?±?2.8?Bq?kg^?1 respectively. The radium’s equivalent activity, annual effective dose, absorbed dose rate, hazard index, radioactivity level index, activity utilization’s index and exposure rate are calculated for determination of radiological risk. The concentration of ²²⁶Ra (in the 71.4% of samples), ²³²Th (in the 71.4% of samples) and ⁴⁰K (in the 14.3% of samples) in the granite samples are higher than average radioactivity concentrations of this radio-isotopes defined by ICRP (35.0, 30.0 and 400.0?Bq?kg^?1, respectively).     

基于机票超售模型的高校图书馆网上预约管理策略

由于图书预约管理体制的不完善,预约借书成功率不高,大量预约登记图书滞留,严重影响图书的流通,因此合理可行的预约管理方案是各高校图书馆共同的迫切需求.基于机票超售模型,结合高校图书馆的实际情况,根据预约者是否按时来图书馆领取预约图书,总体分析复本数、预约期限、预约成功率与图书滞留天数的关系,应用Matlab7.0求解最佳的预约方案来减少预约服务造成的图书滞留.并且以天津大学图书馆为例验证模型效果,以图书滞留天数衡量预约图书流通情况,应用高校图书预约模型对预约方案进行改进,使得预约图书滞留天数明显减少,成功达到提高预约图书流通率,更好地为高校师生服务的目的.