某大型铁钛矿区地下水环境现状调查与评价

通过对某大型铁钛矿区地下水环境现状的调查,并根据该矿区重点部位地下水质分析数据,采用单因子标准指数法对该矿区地下水质进行了详细分析,结果显示除亚硝酸盐和高锰酸盐指数有超标现象外,该矿区地下水其余指标均能达到《地下水质量标准》中Ⅲ类标准水质要求,说明该矿区内地下水环境质量总体状况较好。     

Oxygen Transport In and Around the Systemic Capillary in Hyperbaric Environment

Oxygen transport from a systemic capillary to its surrounding tissue region in the hyperbaric environment is analyzed. Longitudinal and transversal diffusion in the capillary and tissue regions, convective effect of the blood, and equilibrium chemical kinetics of oxygen with hemoglobin are studied in this model. The effect of capillary wall permeability and capillary wall pressure gradient constant on the oxygen transport is also investigated in this study. The nonlinear oxyhemoglobin dissociation curve is considered at hyperbaric environment; further, the zeroth- and first-order oxygen uptake kinetics are considered for the oxygen consumption by the tissue cells. The analytical solution for the oxygen transport in both capillary and tissue regions is obtained using the method of eigenfunction expansion. It is noticed that the amount of oxygen consumption in the tissue region is larger with the first-order metabolism than the zeroth-order metabolism. It is also seen that in the first two-fifth part of the tissue, oxygen is delivered by longitudinal and transversal diffusion, and in the rest of the tissue, it is transported by transversal diffusion only.     

Airflow and Deposition of Nano-Particles in a Human Nasal Cavity

A 3D computational model was developed to study the flow and the transport and deposition of nano-size particle in a realistic human nasal passage. The nasal cavity was constructed from a series of MRI images of coronal sections of a nose of a live human subject. For several breathing rates associated with low or moderate activities, the steady state flows in the nasal passage were simulated numerically. The airflow simulation results were compared with the available experimental data for the nasal passage. Despite the anatomical differences of the human subjects used in the experiments and computer model, the simulation results were in qualitative agreement with the experimental data.

Deposition and transport of ultrafine particles (1 to 100 nm) in the nasal cavity for different breathing rates were also simulated using an Eulerian-Lagrangian approach. The simulation results for the nasal capture efficiency were found to be in reasonable agreement with the available experimental data for a number of human subjects given typical anatomical differences. The computational results for the nasal capture efficiency for nano-particles and various breathing rates in the laminar regime were found to correlate well with the ratio of particle diffusivity to the breathing rate especially for the particles smaller than 20 nm. Based on the simulated results, a semi-empirical equation for the capture efficiency of the nasal passage for nano-size particles was fitted in terms of Peclet number.     

Thermal Stresses Around a Heated Hole in a Large Glass Plate

The problem of sealing a hole in a cool glass plate under conditions at or above annealing temperatures is examined. By use of the well-known equations for stresses in thin circular disks and the application of proper boundary conditions, the concept of a negative temperature distribution (a method of superposition used in stress analysis) that will represent the cooling leads to the conclusion that, under these conditions, the stress in the glass near the hole is independent of the temperature distribution around the hole and dependent only on the physical constants of the glass and the temperature of the lateral surface of the hole.     

井眼附近地应力数值模型研究

针对井眼周围岩石的受力情况,通过ANSYS有限元分析软件建立了7个二维数值模型,分析研究了均匀地应力和不同的远场应力对井眼及周围产生的影响,分析了井眼内和井眼外岩石的杨氏模量的差异和钻井过程中流体压力对其所产生的影响。在均匀地应力条件下,地应力的大小和方向是均匀地变化的,应力的非均匀性是井眼附近的应力轨迹发生变化的最主要原因。在非均匀地应条件下,井眼周围的应力轨迹会变为椭圆形。地应力的非均匀性以及岩石强度参数(如杨氏模量)的变化,对于井眼附近的地应力等值曲线形状的改变起着非常重要的作用。钻井液的压力以及非均匀地应力影响着井眼内外的应力变化。     

干燥过程中脉动气流与物料间的热量传递特性

脉动燃烧装置用于干燥过程时具有热效率高和污染物排放量少等优点，但由于目前对其热质传递的特性缺乏深入的了解，限制了此类干燥器的广泛应用。为了深入了解脉动燃烧干燥过程的传热特性，我们建立了一台Hehnholtz型脉动燃烧器，所用燃料为液化气，采用水冷方式。通过脉动气流与黄铜球之间的对流传热实验，应用集总热容法确定了在不同频率脉动气流中黄铜与气流间的对流传热系数，探究了脉动频率对脉动燃烧干燥过程气流与物料间对流传热系数的影响，并建立了相应的准数关联式。应用建立的关联式，对耐火土颗粒在脉动燃烧气流中的干燥过程进行了预测，并与实验值作了比较，结果表明预测值与实验值吻合较好。     

矿井中央泵房风流逆转原因的分析研究

基于峰峰集团公司某矿二水平中央泵房发生风流逆转的现象,对其产生的原因进行了分析,制定并实施了加强主副井底通风管理等整改方案。同时提出了预防矿井特殊时期主井系统发生风流逆转的思路和措施。     

Manikin test for flame engulfment evaluation of protective clothing: Historical review and development of a new ISO standard

The overall performance of a firefighter turnout suit can only be evaluated using both bench‐scale tests and an assessment based on an instrumented manikin under defined, close to real‐life conditions in a laboratory. Using manikins in rating protective clothing has already a long history which will be reflected in this paper. Efforts all over the world to reproduce a flame engulfment situation in a laboratory are currently being combined in a new draft international standard (ISO/DIS 13506.3). A round robin test showed an acceptable reproducibility for this method based on a manikin test and a gas burner system. An overview of existing measurement systems and the results of this round robin are discussed and possible improvements for the standard flame engulfment test method are proposed. Copyright © 2006 John Wiley & Sons, Ltd.     

一串上升气泡周围流体的湍动特性(英文)

The turbulence behavior of gas-liquid two-phase flow plays an important role in heat transfer and mass transfer in many chemical processes. In this work, a 2D particle image velocimetry (PIV) was used to investigate the turbulent characteristic of fluid induced by a chain of bubbles rising in Newtonian and non-Newtonian fluids. The instantaneous flow field, turbulent kinetic energy (TKE) and TKE dissipation rate were measured. The results demonstrated that the TKE profiles were almost symmetrical along the column center and showed higher values in the central region of the column. The TKE was enhanced with the increase of gas flow and decrease of liquid viscosity. The maximum TKE dissipation rate appeared on both sides of the bubble chain, and increased with the increase of gas flow rate or liquid viscosity. These results provide an understanding for gas-liquid mass transfer in non-Newtonian fluids.     

我国不同区域风电场的腐蚀环境及防腐技术分析

分析了我国"三北"地区、东南沿海地区以及黄河以南内陆地区风电场的气候特点和腐蚀环境,并针对性地提出不同区域的气候环境下风力发电设备的不同零部件、不同部位应采取不同的防腐技术,为大规模发展风电场提供借鉴。     

某典型涉汞企业周边土壤汞污染评价

为探究含Hg废弃物处置、氯化汞及CB型低汞触媒的生产活动对厂区周边土壤Hg含量的影响,以贵州某典型企业周边土壤汞为研究对象,采用地累积指数法、潜在生态风险指数法对土壤Hg污染进行评价。结果表明:土壤Hg含量的平均值为1.58mg/kg,超过了贵州省土壤背景值;地累积指数平均值为3.07,达到了偏重污染水平;潜在生态风险系数平均值为572.73,达到了极强生态风险水平。建议采取有效措施以防止对周边土壤Hg污染影响。     

Aerosol Characteristics in a Subway Environment

This paper presents an attempt to characterize biological and nonbiological aerosols in a subway environment. This opportunity to study a subway station atmosphere was approached as a collaboration of different organizations within the Department of Defense (DoD) and a suite of instruments was assembled for real-time monitoring, sample collection, and subsequent sample analysis. Based on ultraviolet (UV) fluorescence, aerosols of a biological nature were found to comprise a small fraction of the total aerosols (typically <1%). The total number concentration of aerosols exhibits a diurnal cycle that depends on the station usage. Several bacterial species were identified using polymerase chain reaction (PCR) analysis. The most common element in the aerosols is iron. Sodium chloride is also prevalent in the aerosol mass.     

循环流化床锅炉临界流化风量确定及影响因素

循环流化床锅炉的临界流化风量是锅炉设计、运行的重要参数,结合YG240—3．82／450型循环流化床锅炉临界流化风量的测试,笔者提出了临界流化风量的测试方法,同时对影响循环流化床锅炉临界流化风量参数的重要因素进行了讨论。     

Local Behavior of Deposition Velocity onto a Flat Plate in Horizontal Airflow under the Influence of Thermophoresis

In this study, the Gaussian Diffusion Sphere Model (GDSM) and the Statistical Lagrangian Particle Tracking (SLPT) approach were employed and adjusted to calculate the local deposition velocity onto a flat plate in horizontal airflow. The GDSM and the SLPT approach were validated by comparing the predicted local deposition velocities with those determined by solving the equation of convective diffusion. Both the GDSM and the SLPT approach were found to be accurate in calculating the local deposition velocity onto a flat plate in horizontal airflow. In addition, the GDSM was much more efficient than the SLPT approach in terms of the calculation time. Finally, a parametric study on the local deposition velocity onto a flat plate exposed to horizontal airflow was performed using the GDSM with the consideration of the effects of the gravity, convection, diffusion, and thermophoresis.

Copyright 2015 American Association for Aerosol Research     

惰性气体保护气流粉碎技术在农药加工中的应用

为了解决易燃、易爆、易氧化物料的超细粉碎难题,根据可燃粉体爆炸特性,按惰化防爆原理,研发成功惰性气体保护气流粉碎系统。重点论述该系统的工艺、装置、结构特点,探讨其在化工、农药、医药、金属、稀有金属和新能源等行业中的应用,实现了安全、环保、节能、高品质的生产。     

重庆某再生铅企业周边铅尘污染分析与评价

以重庆市某再生铅企业周边为研究区域,根据当地气象与地形条件确定采样点,依据《环境空气质量手工监测技术规范》采集该区域的空气样本,依据《环境空气铅的测定火焰原子吸收分光光度法》测定样本中铅尘的浓度,分析了铅尘的空间分布特征及其影响因素。铅污染指数法评价结果表明,厂区周边环境空气中普遍存在着较严重的铅尘污染。重金属健康风险模型(CDI)评价结果表明,铅尘致癌风险指数范围2.05×10-6~1.51×10-5,非致癌风险度范围为0.012~0.031。基于IEUBK模型的健康风险评价表明,研究区域内儿童受体中血铅浓度超过100μg/L的概率为99.756%,存在较高的环境健康风险。     

骑马走禾木

不同于大城市的喧嚣浮躁,禾木舒适恬静,自然风光优美,树木就是这里的一切。想进村,那就骑匹马。