Detection and Characterization of Avastrovirus Associated with Diarrhea Isolated from Minks in China

Astroviruses are becoming a growing concern in veterinary and public health. Many astrovirus species are associated with enteric diseases have been described in both mammalian and avian hosts. In the present study, 23 fecal samples from diarrheic minks were collected in Liaoning and Shandong Province, and an investigation of astrovirus was performed using biochemical methods and RT-PCR assay with specific primers. A total of four mink astroviral isolates were detected from sick minks with diarrhea problems. Further sequencing and characterization of the partial ORF1b gene and ORF2 gene segments revealed low sequence identities (20.0–85.3 and 31.8–87.2 %) with known astroviral strains, indicating the emergence of a novel clade of astroviruses. Some new features of the astroviral genome have also been discovered. The phylogenetic tree revealed that all samples were distantly related to mink astrovirus and were closely related to chicken astroviruses and turkey astroviruses. MK/DL-1, MK/DL-2, MK/SD-1, and MK/SD-2 formed a new clade and were found to be more closely related to astroviruses from birds than to other mink strains, indicating past cross-species transmission and considerable zoonotic potential.     

豆腐废水廉价培养制备微生物絮凝剂的研究

从活性污泥中筛选出一株有高效絮凝活性的菌株,经鉴定为酵母属(Saccharomyces sp).以豆腐废水为廉价培养基培养高效菌产生微生物絮凝剂,含有絮凝活性物质的发酵液的上清液对4g/L高岭土悬浊液的絮凝率达95.6%.正交实验表明,产生微生物絮凝剂的优化培养条件为:豆腐废水体积分数25%,初始pH值5.0,摇床速度160r/min,温度30℃.培养产生的微生物絮凝剂最佳收获时间为48 h.微生物絮凝剂在酸性和碱性环境中均有较好的适应性和热稳定性.     

环境中大肠杆菌快速生物检测技术研究进展

大肠杆菌作为水质卫生学指标,在环境水质监测中起着非常重要的指示作用.近年来为了克服大肠杆菌常规监测方法的不足,基于现代生物技术原理展开的环境中大肠杆菌的快速检测技术是国内外的研究热点.本文对环境介质大肠杆菌的分子生物学监测方法、免疫学检测方法等的原理及其在环境领域中的应用进行了综述和分析,并在此基础上对大肠杆菌的仪器化发展进行了展望.指出以现代生物技术为核心的并结合现代仪器技术的大肠杆菌快速检测技术将具有良好的应用前景,大肠杆菌的快速检测技术应向操作简单、快速、高灵敏度以及低成本方向发展.     

Distribution characteristics and indicator significance of Dechloranes in multi-matrices at Ny-lesund in the Arctic

In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment,soil, moss, and dung collected from Ny-lesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus(DP) to total DP(fanti) in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18,0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater,sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.     

基于Bayes误差修正的我国能源消费需求组合预测研究

鉴于能源需求系统的复杂性，为了更科学地分析相关经济因素的变化对我国能源需求的影响效应，本文首先利用通径分析法分析了能源需求的主要影响因素及其对能源需求的直接与间接作用，结果表明经济增长、全国总人口、能源消耗结构是决定能源消费需求的主要因素，其中，经济增长为能源需求的主要决定因素，能源消费结构为能源需求的主要限制性因素。在此基础上，文章考虑了多重共线性和预测有效性问题，分别建立了偏最小二乘（PLS）及趋势外推的单一预测模型，然后基于最优组合预测理论建立了偏最小二乘（PLS）——趋势外推组合预测模型。最后，利用Bayes计理论得到了预测误差的概率分布和组合预测的区间估计。结果表明，利用预测误差的Bayes估计来修正组合预测的结果，将得到更为精确的结论。     

纳米磁流体及其在水资源保护中的应用前景

在简要讨论水体油污染严重,保护水资源重要性的基础上,介绍基于纳米科学技术的新型材料纳米磁流体的制备、性质及其重要应用。重点讨论纳米磁流体在水体油污染治理中急待深入开展的研究内容及其在水资源保护中良好的应用前景。     

对马陵山地震台观测环境的分析

1　台站概况马陵山地震台位于郯城县城东北 2 0千米马陵山主峰西坡 ,地理坐标东经 1 1 8°2 7′2 1″,北纬34°4 2′8″ ,海拔 1 1 0米。台站位于沂沭断裂带内安丘———莒县断裂带东侧。台基岩石为白垩系紫红色砂岩、粉页岩 ,地层倾向东南 ,倾角 6 0°～ 70°。受断裂构造影响 ,台基岩石比较破碎。该台是海城地震后 ,根据国务院 6 9号文件为加强郯庐活动断裂地震监测与研究而设立的。 1 975年 3月建成 ,同年部分仪器投入观测 ,台站大部分仪器放置在部队开挖的备战坑道 ,坑道全长1 51 5米 ,洞内年温差小于 0 3℃ ,从环境上看是比较理想的。…     

变截面门式刚架结构极限承载力分析

采用变截面薄腹构件是门式刚架结构轻型化的主要措施之一。如何利用变截面薄腹构件的腹板屈曲后强度并同时保证构件乃至结构的安全度始终是门式刚架结构工程设计的重要内容。根据有效宽度法的基本思想,提出了相关屈曲系数概念,在变截面H钢构件双重非线性数值分析基础上获得的局部屈曲荷载拟合公式,应用于变宽度楔形腹板的有效宽度简化计算公式当中。应用改进后的有效宽度法,进行了变截面门式刚架结构考虑构件局部屈曲影响的极限承载力分析,探讨了腹板平均宽厚比、腹板楔率对结构极限承载力的影响,提出了对变截面门式刚架结构优化设计的工程建议,并具有工程指导意义。     

A HYDRODYNAMIC MODELING STUDY TO DETERMINE THE OPTIMUM WATER INTAKE LOCATION IN LAKE PALDANG,KOREA1

A three‐dimensional hydrodynamic model was applied to Lake Paldang, South Korea. The lake has three inflows, of which Kyoungan Stream has the smallest flow rate and poorest water quality. Since all drinking water intake stations are located near the confluence of Kyoungan Stream within the lake, this contaminated tributary may have a significant impact on the quality of drinking water sources. The optimum drinking water intake location was determined from the applied model. The model was calibrated and verified using the data measured under different hydrological conditions. The model results were in reasonable agreement with the field measurements in both calibration and verification. The circulation and spreading patterns of the incoming flows in the lake, as well as their composition ratios to the drinking water intakes were determined from the model, and three alternative intake locations were proposed. The simulation results suggested that the horizontal and vertical relocations of the intake aqueduct could significantly decrease the composition ratio of the contaminated water. From this study, it was concluded that the three‐dimensional hydrodynamic model could successfully simulate the temporal and spatial mixing patterns of incoming flows and become a useful tool in determining the optimum water intake location in Lake Paldang.     

库水作用下公路土质岸坡稳定性影响因素综合评判

以三峡库区公路土质岸坡为研究对象,通过对库水作用的影响效应分析,建立了岸坡稳定性评价的参数指标评价体系以及相应的分级标准.在此基础上,应用影响因素综合评判方法,对实例岸坡进行了稳定性分级评价,评价结果与实际情况基本相符.