生物膜过滤深度净化水技术研究

以古交镇城底煤矿生活污水处理厂二级出水为研究对象,采用F/BF净化工艺,进行了污水深度处理的生产性试验。研究表明,该工艺对二级处理后的生活污水具有稳定、高效的净化能力,出水水质基本达到地面水Ⅳ类标准,可用于工业冷却水和低压水暖锅炉补充水,具有显著的经济效益和环境效益。试验还对不同滤料进行了分析,认为作为工业废料的炉渣是一种廉价、高效的新型生物膜过滤材料。     

Initiation of a multiple peat slide on Cuilcagh Mountain,Northern Ireland

In October 1998 a multiple peat slide occurred on the northern slopes of Cuilcagh Mountain, Co. Fermanagh, in response to a high‐magnitude rainfall event. Few peat slides have been recorded in Ireland, and a detailed field survey and investigation of the failure was undertaken within four weeks of the event. The morphological evidence indicated a distinct sequence of events which appeared to begin with the failure of a small segment of slope above a degraded transverse drainage ditch which was cut less than ten years previously. This segment of slope was no more than 42 m wide and 25 m long, with 0·7 m of peat overlying up to 0·5 m of a pale coloured clay, the latter containing small pipes and resting on the surface of a darker coloured loamy material. The failure surface was located at or near the base of the pale clay layer. Finite element software was used to model hydrological conditions within the upper segment of slope and to calculate factors of safety for different slope configurations including the presence or absence of a drain or a subsurface pipe. Using the peak shear strength of the pale clay, as determined in the laboratory, both the drain and subsurface pipes were required to obtain a factor of safety of 1·0 or less. Allowing for the uncertainties associated with the hydrological modelling of the pipes, it is suggested that the cutting of the drain and the hydrological impacts of its subsequent degradation are ultimately responsible for the failure. Copyright © 2001 John Wiley & Sons, Ltd.     

物理海洋观测研究的进展与挑战

从当今物理海洋所面临的若干前沿科学问题出发,重点探讨了物理海洋观测研究所面临的任务与挑战,包括大洋边界流系统、海洋湍流及跨等密度面混合以及海洋热含量和淡水平衡等.在已有的基础上,对我国在深海研究领域特别是物理海洋观测方面提出了几点针对性的建议.     

不同土壤热通量测算方法的比较及其对地表能量平衡闭合影响的研究

土壤热通量是地表能量平衡的重要分量,对其测算方法的研究对理解能量平衡过程具有十分重要的意义.利用2010年馆陶站土壤热通量等相关观测数据对多种测算土壤热通量的方法:实测土壤热通量和热储存量的结合方法(PlateCal)、热传导方程校正法(TDEC)、谐波分析法(HM)、平均土壤热电偶法(TCAV)、耦合热传导—对流法(ITCC)获取的地表土壤热通量进行了对比分析,并且采用最优方法计算馆陶站2008-2010年的地表土壤热通量,分析了该站土壤热通量日、季节变化特征.主要结论如下:①PlateCal和TDEC法分别为获取土壤热通量的最优观测与计算方法,而HM,TCAV和ITCC法计算结果均不理想;②PlateCal与TDEC法对地表土壤温度均不敏感,而HM法对地表土壤温度则比较敏感,各种地表土壤热通量的观测与计算方法均对土壤湿度敏感;③馆陶站冬小麦、玉米覆盖地表及地表裸露时期的地表土壤热通量均呈现典型的日、季节变化特征,与净辐射变化趋势一致;④考虑热储存后,可将馆陶站2010年各月地表能量闭合率提高4％～11％,对2008-2010年的年能量平衡闭合率提高3％～5％.     

The processes and characteristics of mass balance on the Urumqi Glacier No. 1 during 1958–2009

As a solid reservoir, a glacier can regulate regional water resources. The annual net mass balance directly reflects the fluctuation of the glacier and climate variability. Based on 51 years of mass balance observation data, the mass balance of Tianshan Mountains Urumqi Glacier No. 1 experienced a nine times positive balance fluctuation and nine times negative balance fluctuation. There were 35 and 16 negative and positive balance years, respectively. From 1996/97 to 2008/09, 12 consecutive negative balance years were observed at Tianshan Mountains Urumqi Glacier No. 1. These results demonstrate that the Urumqi Glacier No. 1 is experiencing a strong negative balance, and the strongest negative balance, -931 mm w.e. (mm water equivalent), during the observation period occurred in 2008. In addition, the cumulative mass balance reached 13,709 mm w.e. in 2008. However, in 2009, the mass balance was positive at 63 mm w.e. The equilibrium-line altitude changes with the fluctuation in the mass balance, and the effective mass balance gradient is 7.4 mm/m. In this paper, the headwaters of the Urumqi River were analyzed using meteorological data from 1958 to 2009, including the average seasonal temperature and precipitation. The results showed that the main factor associated with the mass balance variation of Glacier No. 1 is the fluctuation in the summer air temperature, followed by changes in the precipitation.     

Current and Future Applications of 3-D Global Earth-Ionosphere Models Based on the Full-Vector Maxwell’s Equations FDTD Method

Advances in computing technologies in recent decades have provided a means of generating and performing highly sophisticated computational simulations of electromagnetic phenomena. In particular, just after the turn of the twenty-first century, improvements to computing infrastructures provided for the first time the opportunity to conduct advanced, high-resolution three-dimensional full-vector Maxwell’s equations investigations of electromagnetic propagation throughout the global Earth-ionosphere spherical volume. These models, based on the finite-difference time-domain (FDTD) method, are capable of including such details as the Earth’s topography and bathymetry, as well as arbitrary horizontal/vertical geometrical and electrical inhomogeneities and anisotropies of the ionosphere, lithosphere, and oceans. Studies at this level of detail simply are not achievable using analytical methods. The goal of this paper is to provide an historical overview and future prospectus of global FDTD computational research for both natural and man-made electromagnetic phenomena around the world. Current and future applications of global FDTD models relating to lightning sources and radiation, Schumann resonances, hypothesized earthquake precursors, remote sensing, and space weather are discussed.

Comparison of alternative upscaled model formulations for simulating DNAPL source dissolution and biodecay

This paper compares the performance of analytical and numerical approaches for modeling DNAPL dissolution with biodecay. A solution derived from a 1-D advective transport formulation (“Parker” model) is shown to agree very closely with high resolution numerical solutions. A simple lumped source mass balance solution in which with decay is assumed proportional to DNAPL mass (“Falta1” model) over- or underpredicts aqueous phase biodecay depending on the magnitude of the exponential factor governing the relationship between dissolution rate and DNAPL mass. A modification of the Falta model that assumes decay proportional to the source exit concentration is capable of accurately simulating source behavior with strong aqueous phase biodecay if model parameters are appropriately selected or calibrated (“Falta2” model). However, parameters in the lumped models exhibit complex interdependencies that cannot be quantified without consideration of transport processes within the source zone. Combining the Falta2 solution with relationships derived from the Parker model was found to resolve these limitations and track the numerical model results. A method is presented to generalize the analytical solutions to enable simulation of partial mass removal with changes in source parameters over time due to various remedial actions. The algorithm is verified by comparison with numerical simulation results. An example application is presented that demonstrates the interactions of partial mass removal, enhanced biodecay, enhanced mass transfer and source zone flow reduction applied at various time periods on contaminant flux reduction. Increasing errors that arise in numerical solutions with coarse discretization and high decay rates are shown to be controlled by using an adjusted decay coefficient derived from the Parker analytical solution.     

Accelerator mass spectrometry of the actinides

Accelerator mass spectrometry (AMS) is presently the most sensitive technique for the measurement of actinides with half-lives greater than about 5000 years. Here, the principles and methodology of heavy-element AMS as applied to ^{239,240,242,244}Pu and ²³⁶U are described, and the ways in which these have been implemented in various laboratories around the world are detailed. Actual or potential applications of the method in the areas of environmental science, biomedicine, and nuclear safeguards are reviewed.     

裂隙网络模拟与REV尺度研究

研究了利用平面四边形模拟节理岩体三维裂隙网络的方法。在生成裂隙网络时,同时考虑结构面几何参数和力学参数的随机性。利用裂隙网络研究了确定岩体REV尺度的指标。在此基础上,编制了岩体裂隙网络模拟程序、裂隙网络图形输出程序和岩体REV尺度指标分析程序。通过算例分析,验证了研究成果及程序的合理性,并得出了岩体REV尺度约为各组裂隙中最大迹长期望值3~4倍的结论。研究成果为后续计算岩体等效力学参数奠定了基础。