Stochastic differential equation software reliability growth model with change-point

This paper presents software reliability growth models （SRGMs） with change-point based on the stochastic differential equation （SDE）.Although SRGMs based on SDE have been developed in a large scale software system,considering the variation of failure distribution in the existing models during testing time is limited.These SDE SRGMs assume that failures have the same distribution.However,in practice,the fault detection rate can be affected by some factors and may be changed at certain point as time proceeds.With respect to this issue,in this paper,SDE SRGMs with changepoint are proposed to precisely reflect the variations of the failure distribution.A real data set is used to evaluate the new models.The experimental results show that the proposed models have a fairly accurate prediction capability.     

路堑坡体锚固施工及质量控制

文章通过对运三高速公路六A合同段砂质路堑高边坡治理工程的施工实践分析总结,找到了砂质路堑高边坡治理的有效方法———锚杆框架、挂网喷锚防护。     

异自旋中心有机铁磁体分子设计

采用量子化学从头算ＵＨＦ方法对系列异自旋三自由基体系的基态自旋耦合规律进行研究，并对组成不同的异自旋（ｈｉｅｔｅｒｏ ｓｐｉｎ）三自由基进行了系统的比较，为新型有机磁性材料的实验合成提供了理论依据。     

“文道自觉”在“五四”时期的流变

文学给中国文人的诱惑使文道自觉难以实现 ,写作状态的单调和创作主体的缺乏活泼 ,也是其　　带来的最大弊病。2 0世纪初的文坛虽然初现文道自觉的端倪 ,但由于种种原因 ,这种自觉又迅速地被搁置。文　　学革命的意义在很大的程度上只是一种对“新”的追求。在某种意义上 ,“文道自觉”在“五四”时期走了一　　条循环的路。新文学史上的众多现象在一定程度上也呈现出单一色调     

信息化,网络化进程中的技术较量：——病毒与杀毒综述

８０年代后期，从“巴基斯坦智囊”病毒开始，计算机病毒开始大肆侵害计算机软件系统。９０年代以来，随着网络技术的发展和广泛应用，计算机病毒给全世界用户都带来极大危害。但目前国内也有ＫＶ３００、瑞星、ＫＩＬＬ、ＶＲＶＮＴ、ＰＣ－ｃｉｌｌｉｎ等杀毒软件，它们都有非常有效的专项技术和较大的市场占有率，但由于创新程度、资金支持以及经营方面的欠缺，也面临国外杀毒软件的冲击。     

N-对硝基苯甲酰四氢噻唑2-硫酮与甘氨酸的反应

在三聚氯氰存在下对硝基苯甲酸与四氢噻唑-2-硫酮反应得到N-对硝基苯甲酰四氢噻唑-2-硫酮．在K2CO3存在下产物与甘氨酸反应得到N-对硝基苯甲酰甘氨酸，与N-甲基甘氨酸反应得到了水解产物对硝基苯甲酸．     

DK——2A型单体液压支柱低压密封质量检测仪

单体液压支柱低压密封质量,直接影响到工作面安全生产。为使密封质量检测过程自动化、定量化,研制了DK—2A型单体液压支柱低压密封质量检测仪。该检测仪采用单片机控制,以PC—1500计算机进行数据处理,一次可检测15根支柱,提高检测效率四至八倍。本文论述检测仪的工作原理、硬件及软件设计,并给出程序流程图。此外,对单片机测周期误差进行了分析。     

超塑变形中的晶粒尺寸效应

分析了晶粒尺寸在各种机制中对总变形的影响;晶粒尺寸不同时材料变形的微观特征;晶粒尺寸对晶界滑移速率的影响。讨论了超塑变形中的区间转变;定量表达了晶粒尺寸和变形温度对区间转变应变速率的影响;进而提出临界晶粒尺寸及临界变形温度的新概念及表达式。并以Al-Zn-Mg合金对以上理论分析进行了验证。     

Distributed modeling of the beginning and ending dates and durations of limited temperatures over the rugged terrain of Chongqing

A physically based empirical model was established for the beginning and ending dates (BED) of limited temperatures.Data used were daily mean temperatures from 34 conventional stations in the Chongqing region,measured from 1961 to 2000.Using this model in combination with the distributed modeling results of monthly mean temperatures,we developed a method for creating a distributed simulation of the BED and durations of limited temperatures in the rugged terrain of Chongqing.Spatial distribution maps were generated at a resolution of 100×100 m for the BED and durations of the limited temperatures of 0,10,15 and 20.Simulations suggest that the distributed model is able to successfully reveal the macroscopic trends and local distributions.For the modeled BED,the mean absolute bias error is 0.6-2.4 d.Cross-validation and case-year tests show mean absolute bias errors of 1.3-2.8 d and 0.7-2.5 d,respectively.Comparison shows that the simulation results are consistent with the field investigations.This implies that the simulations are as good as observations,thus providing a viable technique for simulating mountainous heat resources using conventional meteorological data.