紫外/臭氧复合杀灭水中细菌性能研究

为开发一种高效灭菌方法,研究了UV/O3的复合灭菌性能,对紫外辐射、臭氧和羟基自由基等在体系中的各自作用进行探讨,同时考察pH值、温度等对灭菌效果的影响.结果表明,UV/O3较单独紫外或臭氧灭菌时效果有所提高,在初始臭氧质量浓度为5.02mg·L-1,液面紫外辐射强度为6.5mW·cm-2,灭菌时间1.5～9.0s时,UV/O3对细菌总数灭菌率达3.6～6.4,单独紫外时为1.8～4.7,单独臭氧时仅为1.6～3.0.羟基自由基的产生是复合灭菌效果增加的主要原因.随紫外辐射强度和臭氧投加量的增加,复合灭菌作用得到提高.pH值在5.5～8.5变化时,UV/O3灭菌效果随原水pH值的增加略有提高.温度由10℃上升到27℃时,灭菌效果稍有下降.由此可见,UV/O3是一种高效可行的水体灭菌技术。     

The electrical properties and snow melting of graphite slurry infiltrated steel fiber concrete

The conductivity property of graphite slurry infiltrated steel fiber concrete (GSIFCON) was investigated by the four-probe method. The experimental results show that the electrical resistivity of GSIFCON decreases significantly at a specific concentration of graphite, i e, the percolation concentration. A model was accordingly developed to explain its conductive mechanism, where graphite particles could be served as bridge for conductive network between unconnected fiber chains. For an application, snow melting test of GSIFCON was carried out and a simple heating power analysis was performed. The results reveal that the thermal energy produced by GSIFCON makes snow melting effectively and the electrothermal efficiency can reach approximately 20%.     

High-g impact resistance for epoxy molding compound

The behavior of resistance high-g impact of EMC (epoxy molding compound) with two package models, small outline package (POS) and Globtop, was evaluated by experimental method used Hopkinson bar. At 120,000 g (generated in the Hopkinson bar with widths about 70 μ s) no damage in either the POS devices or the Globtop devices was observed. In order to enhance the EMC’s ability of resistance high-g impact, buffering effect of epoxy resin was also studied. The experimental results above all show that EMC has a better performance of impact resistance at about 120,000 g, and epoxy resin can absorb the stress wave to have the protected ability. The study of this paper could serve as a basis for selection packaging materials and enhance its reliability in high-g impact environment.     

相势复合控藏作用在塔中北部地区的应用研究

相和势对油气藏形成与分布有着重要的控制作用,利用相势复合定位可以对有利勘探目标区进行预测.以塔里木盆地塔中北部地区为例,应用相势复合原理对有利目标区进行了预测.结果表明:塔中北部地区油气的分布宏观上受构造相带和沉积体系展布的控制,微观上砂体的含油气性受岩相和岩石物理相的控制,相控油气作用表现出相对高孔渗的控藏地质模式;塔中地区油气的分布还受界面势能(碳酸盐岩)和位能(碎屑岩)的控制,上构造层油气主要分布在相对低位能处;下构造层油气主要分布在相对低界面势能处.油气的分布受相、势联合控制,优相低势区为油气聚集的有利区带.通过用相势复合理论对塔中油气藏有利目标区进行预测后发现,目前已发现的油气藏落入预测有目标区的概率在90%以上,其预测结果对油气勘探有指导意义.     

Influence of carboxyl groups on the particle size and rheological properties of polyacrylate latices

The PAL was synthesized with BA,MMA and some monomers containing carboxyl groups(for example,acrylic acid(AA) and methacrylic acid(MAA)) as co-monomers by semi-continuous seeded emulsion polymerization technique.The influences of alkalinization temperature,the feeding manner of AA or MAA on the particles size,rheological properties and carboxyl distribution of the latex were discussed,and the rheological mechanism was analyzed.The experimental results show that the PAL system has preferable viscosity and particle size when the alkalinization temperature is 50 ℃.Different distribution of carboxyl group in the particles and different resultant rheological properties are obtained by different feeding manner of AA or MAA into the system.The TEM images show that the particle is a smooth globe with carboxyl group concentrating on the surface and stabilized with electric double layer and nonionic adsorbed layer.The concentration of carboxyl functional group on the surface of particles can be achieved by the specific polymerization technique.The rheologyical properties are determined by accretion of particle volume and variation of the two phase volume ratio resulted from the carboxyl group spreading layer.     

基于灰色关联度的集对分析差异系数研究

针对集对分析中差异不确定系数i的取值不确定问题,分别将差异度与同一度和对立度的关联度作为i的取值,运用灰色理论巾的绝对关联度计算方法对i进行求解,并应用到富锦市土壤质量评价中,结果符合实际情况。研究结果表明,采用灰色绝对关联度计算差异系数是可行的,为集对分析中差异系数i的求解提供了新的思路和方法。     

Tissue response of an osteoinductive bioceramic in bone defect rabbit model

HA/TCP and HA rods (?5 mm×10 mm) were made for implantation in New Zealand white rabbit with different condition. Sixty three rabbit were divided into three groups: group 1 (n=18), group 2 (n=27) and group 3 (n=18). In group 1, 10 mm radius was defected, and one HA/TCP rod was implanted in the muscle a distant away from the bone defect area. In group 2, also, 10 mm radius was defected, one HA rod was implanted in the muscle a distant away from the bone defect area. In group 3, two HA/TCP rods were implanted in the dorsal muscle of the rabbit with bone intact. Histological observation showed that in group 1, some new bone was found only two months after implantation (n=2), and obvious immature woven bone could be observed in these bioceramics from the 3^rd month on. However, in group 3, bone began to be found 6 months after implantation (n=2). In group 2, we could not find any bone tissue up to 9 month’s observation. These results suggest that, first, the bone defect model could significantly accelerate bone formation at non-osseous sites in rabbits; second,. HA/TCP bioceramics were confirmed with osteoinductive property while HA bioceramics without osteoinductive property nearly. Thus, bone defect might be a good animal model for further researches for osteoinductive bioceramics.     

基于增量词集频率的文本主题词提取算法研究*

提出了一种基于增量词集频率的文本主题词提取算法,其核心思想是计算主题词集频率增量,算法从候选主题词集提取主题词时,计算单个候选主题词对主题词集频率的增量,若增量小于给定阈值,则主题词提取算法结束,否则将该候选主题词加入主题词集,继续考察下一个候选主题词。实验结果表明,该算法取得了较好的效果,所获得的主题词能更贴切地反映文章的主要内容。     

红外与可见光复合寻的制导中的快速图像配准方法

对现有多传感器图像配准方法在红外与可见光复合寻的制导应用中存在的计算量大等不足,提出了一种基于部分Hausdorff距离的快速方法和一种两集合相似度的定义,从而实现了有效减小误匹配特征点对的红外与可见光图像快速配准方法.此算法通过分别提取两幅图像边缘上显著特征点,再根据提出的快速方法和两集合相似度定义,粗略估计出图像间的旋转角度、平移量;然后依据此估计值,缩小特征点匹配时匹配特征点搜索范围,求得一致特征点对;最后用最小二乘法求解最优变换参数.实验结果表明了该方法的有效性、快速性.     

Viscous liquid sloshing damping in cylindrical container using a volume of fluid method

Liquid sloshing is a kind of very complicated free surface flow and exists widely in many fields. In order to calculate liquid sloshing damping precisely a volume of fluid method based on finite volume scheme is used to simulate free surface flows in partly filled cylindrical containers. A numerical method is presented to simulate the movement of the free surface flow, in which a piecewise linear interface construction scheme and an unsplit Lagrangian advection scheme instead of Eulerian advection scheme are used. The damping performance of liquid sloshing in cylindrical containers under fundamental sloshing mode is investigated. There are four factors determining the surface-wave damping: free surface, boundary-layer, interior fluid and contact line. In order to study different contributions from these four factors to whole damping, several examples are simulated. No-slip and slip wall boundary conditions on both side wall and bottom wall of the cylindrical containers are studied to compare with the published results obtained by solving Stokes equations. In the present method the first three main factors can be considered. The simulation results show that the boundary-layer damping contribution increases while the interior fluid damping contribution decreases with increase of Reynolds number. Supported by the National Natural Science Foundation of China (Grant No. 10532010)