连铸方坯末端电磁搅拌工艺实践

在开发SWRS82B、GCr15线材过程中,合理地运用了连铸方坯末端电磁搅拌,并对凝固末端位置的选择、搅拌电流的选择、拉速对中心碳偏析的影响进行了阐述.     

基于流重复信息检测来估寻服务节点

Discovery of service nodes in flows is a challenging task, especially in large ISPs or campus networks where the amount of traffic across network is massive. We propose an effective data structure called Round-robin Buddy Bloom Filters (RBBF) to detect duplicate elements in flows. A two-stage approximate algorithm based on RBBF which can be used for detecting service nodes from NetFlow data is also given and the performance of the algorithm is analyzed. In our case, the proposed algorithm uses about 1% memory of hash table with false positive error rate less than 5% . A prototype system, which is compatible with both IPv4 and IPv6, using the proposed data structure and algorithm is introduced. Some real world case studies based on the prototype system are discussed.     

基于布鲁姆过滤器的文本检索系统研究

针对目前文本检索系统出现的信息重复,冗余等问题,提出了一种将布鲁姆过滤器算法与MD5有效结合的方案。对检索关键字进行MD5预处理操作,充分利用MD5的可靠性。并发挥鲁姆过滤器降低检索算法的时间复杂度和空间复杂度的特点,大大提高了检索的快速性,相关性和完备性。     

紫外线辐照技术去除藻类的研究进展

结合国内外相关文献,综述了紫外线辐照对不同典型藻类的影响、紫外线辐照除藻技术的发展利用现状,并分析了紫外线辐照技术除藻的机理,以期为后续深入研究和推广利用提供理论依据。     

Automated image analysis tool for migration fat bloom evaluation of chocolate coated food products

Migration fat bloom remains a major problem in the production of coated confectionary products where a layer of chocolate is added around a filling or other fat containing substrate. Fat bloom quantification is typically done by a human panel scoring samples in time using a low resolution discrete scale. In view of developing a mechanistic model for migration fat bloom, it is important to have a higher resolution. In this paper, a new, high resolution quantitative method based on image analysis is developed. The method is able to detect both the evolution of fat bloom in terms of the disappearance of gloss and the development of “whitish” portions at the chocolate surface. It was successfully applied to distinguish the difference in fat bloom development rate between samples containing different fat concentrations (0, 3 and 6g/100g) coated on fillings containing different amounts of fat (25 and 75g/100g). In the 25g/100g filling fat case, blooming occurred at a very late stage and was caused by the disappearance of gloss. In the 75g/100g filling fat case the development of a “whitish” surface was responsible for the change in acceptability. The newly developed image analysis method is a solid alternative for the panel procedure.     

Biosorption of Naphthalene from Refinery Simulated Waste-Water on Blank Alginate Beads and Immobilized Dead Algal Cells

Abstract

The potential use of blank alginate beads and immobilized dead algal cells for the removal of naphthalene from aqueous solutions was investigated in this study. The effects of contact time, solution pH, and naphthalene concentration on the sorption of naphthalene on blank alginate beads or immobilized dead algal cells were studied. The effect of the presence of other pollutants on the sorption of naphthalene on immobilized dead algal cells was also studied.

Batch adsorption experiments showed that the removal of naphthalene on both sorbents was pH dependent and significant removal of naphthalene was obtained at pH 4. Dynamic sorption experiments revealed that the biosorption of naphthalene on either sorbent was rapid where the equilibrium uptake occurred within 10 minutes, and the biosorption of naphthalene on either sorbent followed the pseudo-second order kinetics. Analysis of the equilibrium sorption data showed that naphthalene sorption on either sorbent could be fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich (D–R) isotherm equations. Competitive biosorption experiments showed that biosorption of naphthalene on immobilized dead algal cells was adversely affected by the presence of either heavy metals such as copper and nickel, and chelating agents such as citric acid.     

A Semi-Lagrangian Study of Circulation and Transport in Lake Ontario

A particle tracking model (PTM) is linked with a hydrodynamic model to evaluate mean seasonal circulation patterns in Lake Ontario, and also to provide a basis for predicting movement of algal blooms. The PTM is based on a random walk algorithm that combines a deterministic advective component with a stochastic component associated with the turbulent diffusivity field to calculate trajectories of neutrally buoyant particles, where both the advective and diffusive velocities are obtained from the hydrodynamic model. Mean circulation is calculated using 30-year average meteorological forcing data collected from five stations around the lake. Seasonal variations in lake circulation are demonstrated, and a clockwise flow in the eastern basin during summer and early fall is identified, contrary to some previous observations that suggest counterclockwise flow. The impacts of Niagara and St. Lawrence river flows on general lake circulation are found to be small, except within approximately 10 km of the river mouth. Development and application of the PTM demonstrate its potential to provide calculations of (Lagrangian) movements as determined from the hydrodynamic output, and to serve as a first step toward development of an algal transport model. Particle tracking helps to visualize flow patterns and provides a means of evaluating the probability a bloom will reach a specified area, given an initial position and the predicted velocity and diffusivity fields. This capability, when set up for real-time applications, can provide an important tool to support management decisions that may be needed when a bloom is observed, for example in predicting potential impacts of the bloom on a beach or a water intake.     

Diarrheic shellfish poisoning due to toxic mussel consumption: The first recorded outbreak in Greece

During the week of 14-20 January 2000, 120 people visited the Emergency Departments of hospitals in Thessaloniki, northern Greece, complaining of acute gastrointestinal illness after eating mussels (Mytilus galloprovincialis). The symptoms indicated diarrhoeic shellfish poisoning, and the toxicity of mussels harvested from Thermaikos Gulf in Thessaloniki during the outbreak was investigated using mouse bioassays. The bioassays revealed toxicity to mice by the mussel samples; while high numbers of toxic algae Dinophysis acuminata were identified in water samples from Thermaikos Gulf. The harvesting of mussels was immediately suspended and a monitoring programme for algal blooms was established from then onwards. During a follow-up of the mussels' toxicity from January 2000 to January 2005, two more mussel samples were found positive for diarrheic shellfish poisoning: one harvested in March 2001 from the area of the outbreak (Thermaikos Gulf) and the other harvested in January 2001 from Amvrakikos Gulf in north-western Greece. However, no sporadic cases or outbreaks were reported during this period.     

微囊藻水华暴发的水动力机理与模拟研究进展

微囊藻水华暴发会加剧水质恶化,影响用水安全,破坏水生态系统平衡,威胁人类健康,是全球普遍面临的水生态灾害之一。微囊藻水华暴发的水动力机理与模拟是开展相关水华防治的关键,是当前环境与生态水力学研究的前沿热点与难点。本文对国内外微囊藻水华暴发的水动力机理与模拟研究工作进行了梳理,包括:归纳了微囊藻自主迁移的生物学机制;总结了静水环境下微囊藻个体与群体的垂向迁移机制;梳理了风生流、异重流等典型流态下微囊藻聚集的水动力机理;从粒子模型与连续介质模型角度,阐述了微囊藻迁移分布模拟方法以及应用;凝练了微囊藻水华暴发水动力机理与模拟研究领域未来需要解决的若干关键问题。     

太湖蓝藻水华胰蛋白酶抑制剂和凝血酶抑制剂的测定

为配合太湖蓝藻的收集处理 ,研究了蓝藻水华的资源化可能 ,在前期工作的基础上 ,通过层析分离并结合活性测定 ,发现太湖蓝藻水华中有多种胰蛋白酶和凝血酶抑制剂