基于虚拟源二叉树射线跟踪算法的改进

文章基于虚拟源二叉树射线跟踪算法,针对目前射线跟踪技术在遮挡测试和路径有效性检测过程中,由于部分遮挡等相交计算导致效率低的问题,使用新的判据代替求交运算,提高了算法效率。采用文章所提算法模型对某微小区的相关场景进行了仿真,并与基于GO(Geometrical Optics,几何光学原理)/UTD(Uniform Theory of Diffraction,一致性绕射理论)混合理论的三维仿真结果进行了比较,结果表明使用该判据可以提高二维射线跟踪算法的效率。在精度要求不高的情况下,文章所提出的二维射线跟踪算法在计算时间上具有较大的优势。     

西部新区试采初期清洁生产实施初探

通过对江苏油田西部新区试采初期不同施工环节中污染源、污染物的分析，针对各种污染物产生的环节，从管理和技术的角度，提出了试采初期实施清洁生产的思路和方法，并对探区的清洁生产长期规划提出了可行性建议。     

Water and solute movement in soil as influenced by macropore characteristics: 2. Macropore tortuosity

The paper describes the results of a laboratory study on the effects of macropore tortuosity on breakthrough curves BTCs and solute distribution in a Forman loam (fine loamy-mixed Udic Haploborolls) soil. BTC were obtained using 2-D columns (slab) containing artificial macropores of five different tortuosity levels. The BTCs were run under a constant hydraulic head of 0.08 m over an initially air dry soil. The input solutions contained 1190 mg l⁻¹ of potassium bromide, 10 mg l⁻¹ of Rhodamine WT, and 100 mg l⁻¹ of FD&C Blue #1. A soil column without macropores served as a control. The displacement of a non-adsorbed tracer was not affected by the tortuosity level. An increase in macropore tortuosity progressively increased the breakthrough time, increased the apparent retardation coefficient (R′), decreased the depth to the center of mass of a given adsorbed tracer, and increased the anisotropy in tracer distribution profile. The relative importance of macropore tortuosity increased with an increase in the adsorption coefficient of the tracer. Compared to macropore continuity, the macropore tortuosity had greater impact on solute distribution profile than in its leaching.     

成矿流体活动的地温信息及地球物理示踪

本文对流体活动与地温结构的相互作用关系流体活动的热效应、地温异常导致的地球化学效应、流体活动 -地热传输的耦合过程及其模拟进行了研究。初步建立了识别流体活动热效应的地球物理及地球化学标志 ,指出通过热史模拟、流体史模拟、热-质迁移模拟及地球物理等方法识别这些标志可以进行流体活动的示踪。     

人工湿地植物及其去污效果研究进展

从人工湿地植物的类型及选择原则、去污机理及效果、去污效果的影响因素等方面,对人工湿地污水处理技术现状进行综述,为人工湿地植物的选择提供参考与帮助。     

Traffic Parameters Estimation to Predict Road Side Pollutant Concentrations using Neural Networks

The analysis aims to evaluate which is the most important among traffic parameters (flows, queues length, occupancy degree, and travel time) to forecast CO and C₆H₆ concentrations. The study area was identified by Notarbartolo Road and bounded by Libertà Street and Sciuti Street in the urban area of Palermo in Southern Italy. In this area, various loop detectors and one pollution-monitoring site were located. Traffic data related to the pollution-monitoring site immediately near the road link were estimated by Simulation of Urban MObility (SUMO) traffic microsimulator software using as input the flows measured by loop detectors on other links of road network. Traffic and weather data were used as input variables to predict pollutant concentrations by using neural networks. Finally, after a sensitivity analysis, it was showed that queues length were the mostly correlated traffic parameters to pollutant concentrations. An erratum to this article can be found at     

Application of aluminosilicate clay mineral-based composites in photocatalysis

Aluminosilicate clay mineral (ACM) is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring. In past two decades, in-depth understanding on unique layered structure and abundant surface properties endows ACM in the emerging research and application fields. In field of solar-chemical energy conversion, ACM has been widely used to support various semiconductor photocatalysts, forming the composites and achieving efficient conversion of reactants under sunlight irradiation. To date, classic ACM such as kaolinite and montmorillonite, loaded with semiconductor photocatalysts has been widely applied in photocatalysis. This review summaries the recent works on ACM-based composites in photocatalysis. Focusing on the properties of surface and layered structure, we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM, i.e., type 1:1 and type 2:1. Not only large surface area and active surface hydroxyl group assist the substrate adsorption, but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts. Besides, we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process. This review could inspire more upcoming design and synthesis for ACM-based photocatalysts, leading this kind of economic and eco-friendly materials for more practical application in the future.     

Effects of Al3+ on the microstructure and bioflocculation of anoxic sludge

The aluminum ions generated from mining aluminum,electrolytic aluminum and the industrial production of aluminum-based coagulants(such as AlCl_3 and Al_2(SO_4)_3) enter sewage treatment plants and interact with activated sludges.An anaerobic/anoxic/oxic(A~2 O) process was used to reveal the effects of Al~(3+) on the pollutant removal efficiencies,bioflocculation and the micro structure of sludge.The results showed that a low concentration of Al~(3+) improved the pollutant removal efficiencies and increased the sludge particle size.However,a high concentration of Al~(3+) hindered microbial flocculation and reduced the pollutant removal efficiencies.With a 10 mg/L Al~(3+) addition,the chemical oxygen demand(COD),total nitrogen(TN) and NH_4~+-N increased by 3%,16% and 27%,and reached as high as 68%,60% and 87%,respectively.At the same time,the dehydrogenase activity,flocculation ability(FA) and contact angle of the sludge reached their maximum levels at 41.3 mg/L/hr,45% and 79.63°,respectively.The specific surface area of the sludge decreased to 7.084 m2/g and the sludge pore size distribution shifted to concentrate in the me soporous range.Most of Al~(3+) was adsorbed on the surface of sludge,changing the physicochemical properties and physical structure of the sludge.     

地下水“三氮”污染来源及其识别方法研究进展

地下水"三氮"污染来源的识别研究对污染控制与修复有重要的意义.在阐述地下水"三氮"污染来源(大气氮沉降、土壤天然有机氮矿化、地表径流氮输入、人类活动氮排放等)及其在我国的分布特征的基础上,总结了国际上常用的"三氮"污染来源识别方法,包括水化学方法、统计学相关方法、区域氮平衡法、稳定同位素示踪法及一些新型示踪方法.指出由于"三氮"污染来源的多样性及污染形成机制的复杂性,单一识别方法在应用中均有较明显的局限性,目前主流识别手段为稳定同位素示踪法与多种识别方法相综合.进一步提出要加强新型示踪方法的开拓、定量识别方法的优化,污染源识别与迁移转化机制、地下水补排条件、地下水-地表水转化关系等研究相结合为未来发展的主要趋势.     

红球菌BAP-1对荧蒽的跨膜运输过程

利用同位素示踪法对红球菌BAP-1跨膜运输¹⁴C-荧蒽的过程进行了研究.结果表明在有ATP抑制剂NaN₃的存在下,红球菌BAP-1细胞膜内所结合的¹⁴C-荧蒽含量几乎无变化.结合对微生物体内包涵体的观察,说明当有ATP抑制剂存在的情况下,荧蒽无法通过细胞膜进入到微生物的体内.这表明若是荧蒽无法通过跨膜运输进入到红球菌细胞内,就不能得到有效的生物降解.在不同的底物浓度条件下,微生物对¹⁴C-荧蒽的跨膜运输过程是主动运输过程;在一定底物浓度条件下,菌体膜结合污染物的量会在一定的条件下达到饱和.结合米氏方程分析了红球菌BAP-1对¹⁴C-荧蒽的跨膜运输动力学过程,结果表明底物¹⁴C-荧蒽与微生物之间一直保持较高的亲和力,较高的亲和体系有助于跨膜运输过程的顺利进行.