高并发校园快递超市系统

为解决校园师生方便收发快递快件, 基于PHP技术设计与实现了一种安全、高并发的校园快递超市管理系统. 系统基于thinkphp开源框架, 采用页面静态化、Memcache等技术, 在Web方式下实现可支持一定并发量的快递快件信息的查询、录入、签收、监控、统计等功能. 结果表明该系统提高了快递超市的工作效率; 规范了快递快件管理; 系统数据可帮助快递企业提供决策支持.     

一种基于本体的语义Web服务发现模型

Web服务已经成为互联网中最为重要的一种计算资源和软件资产,Web服务的大量涌现对服务发现提出了挑战。Web服务发现的关键是Web服务的语义描述的准确性和Web服务检索引擎的检索效率。提出了一种基于本体的Web服务描述方法,采用OWL-S对Web服务进行语义描述,并提出了针对性的Web服务检索引擎。通过试验,该模型结合语义Web服务技术实现Web服务的动态查找与组合,可提高Web服务发现的查全率和查准率。     

重叠细胞图像分离算法的设计

在实际的细胞图像中,经常会遇到重叠现象（又称为聚堆）,即多个细胞聚一起的情形,这给后续的分析处理带来了困难,因此需要设计一个有效的算法,能够将这些重叠在一起的细胞群分离为单个的细胞,文中针对二值化的图像,提出了一个基于形态学的算法,该方法首先利用腐蚀操作,以确定聚堆细胞最终分离为单个细胞的个数,然后再根据腐蚀后的结果,在原妈的二值图像上找到了分离点,从而最终有效地将重叠细胞分离为单个细胞,文中主要     

基于动态LOD 四叉树算法的虚拟地形可视化

在前人的基础上,改进了基于四叉树的LOD模型,通过建立节点判断准则来决定当前视区的细节程度.同时也提出了一种新的裂缝消除方法,即当视点到节点中心距离较远时看到的细节较少,裂缝消除可通过缩减边的方式实现;而当距离较近时需要观察到的细节较多,通过剖分方式实现可使细节变得更丰富,这样就可以在增强简化效果的同时提高实时渲染的速度.     

Mechanism of high-temperature oxidation effects in fatigue crack propagation and fracture mode for FGH97 superalloy

The high-temperature fatigue crack growth behaviors in powder metallurgy(P/M)Ni-based superalloy FGH97 for turbine disk application were investigated at different temperatures(650,700 and 800 ℃)in air using a combination a servohydraulic test system,fractographic and microanalytical investigations.It is found that there is a temperature-sensitive region in which the fatigue life of FGH97 alloy decreases sharply.To further evaluate the crack propagation mode and oxidation effects,interruption experiments were conducted at 700 and 300 ℃,respectively.The results indicate that the reduction of the fatigue lifetime for FGH97 takes place when the fracture mechanism transforms from a predominantly transgranular mode to an intergranular one as the temperature increases.Although the microstructures and mechanical properties may vary with the temperature,they are not the dominating factors contributing to the temperature sensitivity of fatigue property for FGH97.It is the oxidation that governs the fatigue crack growth behaviors in air at elevated temperature.The enhanced thermal activity of oxygen and certain active metal elements result in accelerated oxidation reaction.The brittle oxide intrusions formed at the crack tip and grain boundaries of crack frontier lead to grain boundary weakness,which is responsible for the transformation of crack growth mode and degradation of the fatigue property of FGH97 alloy.     

SC–CO<Subscript>2</Subscript>-assisted rubber dispersion and dynamic vulcanization in blending of PP/EPDM thermoplastic olefin

Supercritical CO₂ (SC–CO₂), as a green medium, was induced in the traditional way of preparing polypropylene/ethylene–propylene–diene terpolymer (EPDM) thermoplastic olefin (TPO) by dynamic vulcanization using a twin-screw extruder. The morphology observation suggested that the SC–CO₂ not only promoted the rubber dispersion, but also facilitated the rubber dynamic vulcanization; therefore, the crosslinked EPDM particles were more densely distributed in the TPOs prepared with SC–CO₂, and existed as a stronger viscoelastic phase restricting the mobility of polymer chains, increasing the complex viscosity and storage modulus and promoting the mechanical properties.     

Thermogravimetric analysis and pyrolysis of waste mixtures of paint and tar slag

We describe thermogravimetric analyses and pyrolysis kinetic studies carried out on hazardous waste mixtures of tar slag, paint slag, paper, sodium sulfate and calcium oxide. Both thermogravimetric (TG) and differential thermogravimetric (DTG) profiles were measured by a thermogravimetric analyzer at different final temperatures, particle sizes and heating rates. Pyrolysis kinetic parameters were calculated by the Coats-Redfern method. Influences of particle size, heating rate and final temperature on pyrolysis yields and kinetic parameters are also discussed. The results show that final temperature and particle size have a great effect on pyrolysis yields. We find that with increasing temperature the activation energy initially increases to a maximum value and then decreases. This work was presented at the 7 ^th China-Korea Workshop on Clean Energy Technology held at Taiyuan, Shanxi, China, June 26–28, 2008.     

巴氏杀菌奶的微生物生长动力学模型研究

目的通过初级模型和二级模型来描述巴氏杀菌奶中微生物的生长动力学模型。方法样品放置在4、8、16、25、30、37、40和43℃条件下培养,使用IPMP 2013软件进行拟合,初级模型采用Huang模型和Baranyi模型分析不同温度下的生长动力学特征,二级模型采用Ratkowsky平方根模型、Huang平方根模型和Cardinal模型描述温度对其生长速率的影响。结果在所有温度下都能观测到微生物的生长,综合比较2种初级模型的均方根误差(root mean squared error,RMSE)、均方误差(mean squared errorMSE)、赤池信息量准则(Akaike information criterion, AIC)和生长速率,得到2种初级模型具有同等拟合效果;而3种二级模型得到的最低生长温度和最高生长温度分别是-3.191、0.56、-4.962和47.309、45.277、44.408℃。结论 Baranyi模型和Huang模型均适合描述巴氏杀菌奶中微生物菌群的生长,3种二级模型都能用于评价温度对其生长速率的影响,但Ratkowsky平方模型覆盖的温度范围更广,可能更适合描述温度对巴氏杀菌奶中微生物菌群生长的影响。     

基于人工免疫算法的SVG电压外环控制器控制策略

针对高维非线性电力系统复杂的控制对象,在静止无功发生器（SVG）的电压偏差-无功的控制方法上,采用人体免疫系统维持自身功能正常的机理,以稳定电力系统工作状态,提出基于人工免疫算法的SVG外环控制器控制策略。研究中识别电力系统中相应抗原物质的电压变动因素,细胞激活生成过程的模糊建模,运用Mamdani模糊推理和重心中心解模糊方法,得到内环控制所需要的无功参考值指令。通过单机双闭环控制的SVG控制器离线仿真,对三相对称短路故障后控制的影响分析,并与PI控制方式比较。结果表明,所提出的仿生免疫机理的控制方案对于SVG中动态无功调节过程和对电力系统稳定性的控制作用是有效的。