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1.
《环境技术》2005,23(6):49-50
「夕一琴_、几:写下.:一…,:·二礴冬称、一:少…,匕 炭一峨份子扎浮一班珍晃鉴豪鬓理眨夔巫 环境试验 常规兵器三综合环境试验技术研究 第一期 Hop卜1 nson压杆反射 环境适应性和可靠性 综合环境应力可靠性 射拉伸下PMMA动态破坏现象实验研究 大气监测 靠性试验系统的配置设计及主要技术指标论证 13 15 18 21 25 29 32 37 39 43 4649 室内空气监测中的存在问题及对策 浅谈遥感技术在大气监测中的应用 环境治 垃圾焚 低温等 理 烧烟气的环境污染与净化技术 离子体技术在环境工程中的研究进展 烟气脱硫喷淋塔气体旋流实验研究 可见分光光…  相似文献   

2.
在三种介质(二次水,汽油,乙二醇,50℃温度)条件下对PA66及PA66/GF进行95天左右的人工模拟材料在汽车使用环境下的加速试验,对不同老化时间的PA66及PA66/GF试样进行了宏观力学测试及吸湿性测试,并进一步利用示差扫描量热法(DSC),红外光谱及扫描电镜等手段分析老化前后试样的微观结构及组织差异。结合老化前后试样的力学性能变化,揭示了PA66及复合材料的老化规律和机理。实验表明,PA66及PA66/GF在三种介质中拉伸强度呈现下降趋势。其主要机理是介质溶液对试样渗入的结果影响,降低了分子间的相互作用力(范德华力)从而使材料机械性能下降;同时未发现化学作用对材料的力学性能有明显的变化。  相似文献   

3.
正弦振动试验的目的是在试验室内模拟产品在使用、运输和贮存过程中可能经受到正弦振动时的效应。振动对产品引起变形、弯曲、产生裂纹、断裂,造成部件间的相互撞击等,包括由于振动产生的交变应力超过构件所能承受的弹性和塑性极限应力而造成的破坏,以及由于长时间振动的交变应力造成的累积损伤,使产品发生疲劳损坏。特别是在产品的固有频率与激励频率相同而引起共振导致响应幅值急剧增大时,会更加迅速、更多地发生。  相似文献   

4.
通过对复合材料双搭接胶结结构开展单向拉伸试验,并利用理论和数值仿真方法分析对结构在拉伸状态下的胶层剪切应力进行。研究结果表明:胶结件的破坏为胶层与搭接板间的脆性脱粘破坏,无胶层内聚破坏,复合材料搭接板局部有分层损伤产生;应力变化趋势的理论结果和仿真结果一致,数据吻合性好且误差小,剪切应力最大值发生在胶结端部,变化趋势从样件中部到端部先下降再上升;胶结接头的破坏是由于外载作用下胶层内部的剪切应力和拉应力共同作用的结果。  相似文献   

5.
本文运用模型确认理论,对泰勒杆试验在材料动态本构关系确认性方面的应用进行研究。以Johnson-Cook模型描述的OFHC材料为例,采用试验和数值模拟相比较迭代的优化方法,结合灵敏度分析,提出了一种简捷的确认和确定动态本构关系参数的方法。  相似文献   

6.
邓舟  夏洲 《矿山环保》2003,(4):33-37
简要评述了复合粘土防渗材料在生活垃圾填埋场中的应用及其性能特点、质量控制的主要参数,以及在铺设时需要注意的基本事项。膨润土是复合防渗材料的主要原料。由于我国拥有世界上最大的膨润土资源,同时填埋场建设对其有很大的需求,可以预见到,膨润土以及复合粘土防渗材料的开发在我国将具有良好的前景。  相似文献   

7.
本研究通过单轴拉伸试验实现复合材料单搭胶结结构胶面剪切破坏测试,获得了结构的极限剪切强度,同时利用解析法和仿真模拟方法分析了胶层的剪切应力状态。研究结果表明:胶结件的破坏为胶层与搭接板间的脱粘破坏,无胶层内聚破坏;胶层横断面中部剪切应力值最低,胶结区端部产生应力集中,端部应力最大;胶层存在剪切应力的同时,也存在垂直于胶结面的拉应力,其破坏原因是剪应力和拉应力的综合影响结果;平均剪切应力计算结果显示:试验值、理论值和仿真结果分别为8.9 MPa、9.5 MPa和9.2 MPa,理论结果和仿真结果的应力变化趋势一致,理论解和仿真解与试验值的误差均在7%以内,理论分析和仿真模拟可实现胶结结构剪切应力的可靠预报。  相似文献   

8.
开展聚碳酸酯(PC)材料在我国吐鲁番和若羌典型干热自然环境暴晒试验,对试验前后PC材料的色差、黄色指数、光泽度、雾度、透光率等光学性能和表面形貌进行测试与表征,研究PC材料在吐鲁番和若羌两个试验站的老化行为差异。结果表明,PC材料在干热环境暴晒出现了明显的老化失效现象,而且试样在吐鲁番的老化程度大于若羌,说明在辐照、温度和湿度三个主要环境因素中,当温度与辐照量同时处于较高水平时能加剧PC材料的老化。  相似文献   

9.
由于废水处理设施跟不上城乡经济发展的速度,新疆不少流经城镇的小河流已被工业废水和生活污水严重污染,但多数城镇的小河流一般坡度较陡,可以考虑在河流中施放多种接触材料,促使河水自净作用的发挥,国外在这方面已作了不少实验,现将此类实验情况及结论作如下简介,以供参考。  相似文献   

10.
苯系混合气体生物滴滤器净化性能研究   总被引:1,自引:0,他引:1  
马红  羌宁  季学李 《四川环境》2005,24(2):24-26,53
本研究采用纤维附着活性炭(ACOF)和不锈钢丝网为载体材料,进行了气体生物滴滤器(BTF)净化TEX(甲苯、乙苯、二甲苯)混合气体的动态实验研究。实验结果表明最大消除能力值在140g/m3·h左右。由于载体材料的特殊结构和性能,实验研究中实现了对TEX这类疏水性物质在较少停留时间和较大空塔气速情况下的高效连续运行。高负荷运行时,会由于过剩生物质积累引起装置堵塞、压降增加,但设备净化效果变化不显著。  相似文献   

11.
解析研究内部爆炸驱动金属圆筒的运动   总被引:2,自引:0,他引:2  
从柱壳运动的控制方程出发,应用壳壁发生贯穿破裂的Taylor判据,给出了内部爆炸加载下金属圆筒壳壁的运动轨迹、平均破裂时间、破裂应变、半径及破片初速度的解析表达式。结果表明:计算结果与相关文献中的实验结果基本符合。  相似文献   

12.
Although the influence of gas sorption-induced coal deformation on porosity and permeability has been widely recognized, prior studies are all under conditions of no change in overburden stress and effective stress-absent where effective stresses scale inversely with applied pore pressures. Here we extend formalism to couple the transport and sorption of a compressible fluid within a dual-porosity medium where the effects of deformation are rigorously accommodated. This relaxes the prior assumption that total stresses remain constant and allows exploration of the full range of mechanical boundary conditions from invariant stress to restrained displacement. Evolution laws for permeability and related porosity are defined at the micro-scale and applied to both matrix and an assumed orthogonal, regular and continuous fracture system. Permeability and porosity respond to changes in effective stress where sorption-induced strains may build total stresses and elevate effective stresses. Gas accumulation occurs in both free- and adsorbed-phases and due to effective grain and skeletal compressibilities. A finite element model is applied to quantify the net change in permeability, the gas flow, and the resultant deformation in a prototypical coal seam under in situ stresses. Results illustrate how the CO2 injectivity is controlled both by the competition between the effective stress and the gas transport induced volume change within the matrix system and by the dynamic interaction between the matrix system and the fracture system. For typical parameters, initial injection-related increases in permeability due to reduced effective stresses may endure for days to years but are ultimately countered by long-term reductions in permeability which may decline by an order of magnitude. Models suggest the crucial role of stresses and the dynamic interaction between matrix and fractures in correctly conditioning the observed response.  相似文献   

13.
ABSTRACT: The study of wind generated waves is important because waves affect sediment resuspension in lakes. Measurements of wind velocity and wave elevation were made at three different stations in Lake Okeechobee. Significant wave heights were computed using a direct count from the recorded data, and verified by the root-mean-square value approach. The correlation between wind stress and significant wave height also was analyzed. The data revealed a strong correlation. In addition to field measurements, a Boussinesq-type wind-wave model was developed to simulate wind-generated, long-propagating waves. This model included the effects of wind stress and bottom viscous dissipation. Wave elevation and velocity field were evaluated numerically. A six-day simulation using 1996 wind data was conducted. Simulated significant wave heights were found to agree reasonably well with measured values. A predictive wind-wave model provides information about wind generated waves, which is used to compute bottom shear stresses required for sediment resuspension studies.  相似文献   

14.
90Sr、137Cs在某种包气带土壤中的迁移研究   总被引:4,自引:0,他引:4  
杨勇  苑国琪  张东 《四川环境》2004,23(3):85-89
本文叙述了放射性废物中具有代表性的裂变核素^90Sr、^137Cs在某种包气带土壤中的迁移情况研究。使用小型土柱的氚水淋洗实验研究土壤水力学性质,最后进行大型土柱实验研究核素在该包气带土壤中的迁移,并对实验情况进行了数学模拟。用该土壤原状土进行小型土柱的氚水淋洗试验,测得了土壤的水力弥散度为0.32cm,土壤有效孔隙度为0.35。经过290天的大型柱迁移试验表明,土壤对^90Sr的阻滞系数为220.4,在模拟实际降雨量的情况下,^90Sr的平均迁移速度为0.63cm/y,^137Cs在大型柱试验中没有明显迁移。数值模拟^90Sr、^137Cs迁移,得出经过上述大型柱试验相同的条件下,^90Sr、^137Cs迁移的峰位置基本和大型柱试验结果相同。  相似文献   

15.
The impact of the extreme heat wave that affected Melbourne, Australia, in two distinct phases in January and February 2009 was severe, with 374 (heat) and 173 (bushfire) excess deaths. Whilst the human health issues have been covered in detail in policy and academic arenas, much less attention has been paid to the adverse impacts on urban infrastructure. Analysis of this event, underpinned by participatory actor-based research, has shown that the impacts were experienced disproportionately across different infrastructure types. For water, telecommunications and airports, the impacts were relatively minor and the impact on rail transport and roads (and to a lesser extent, seaports) was of moderate significance, whereas research findings indicate that the electricity sector was found to be the most vulnerable. This paper focuses on the sectors that were worst impacted: electricity, rail and road transport. Commentary identifies the direct and indirect impacts of the heat event, including associated cascading effects, as well as considering actual and potential adaptation responses both before and after the event. Concluding, the authors reflect on the implications of the heat wave for urban resilience, emphasising the crucial importance of understanding the urban environment as a complex and interconnected system.  相似文献   

16.
The Western Forest Complex (WEFCOM) of Thailand is comprised of many protected areas and has one of the highest wildlife populations in the country. Populations of wildlife in the WEFCOM have decreased dramatically over recent years. Rapid economic development has resulted in the conversion of forest into agricultural and pastoral land, which has directly and indirectly impacted the wildlife community. This research aimed to evaluate populations of domesticated cattle (Bos indicus) and buffalo (Bubalus bubalis) in the WEFCOM and their possible impacts on the wildlife community. Domesticated cattle and buffalo keepers from 1561 (or 3.3%) of houses in and near WEFCOM were interviewed. The average number of animals per household was 15.6 cattle and 8.5 buffalo. Most villagers released domesticated cattle and buffalo to forage in the protected areas. This tended to have a high impact on the wildlife community in Huai Kha Khaeng Wildlife Sanctuary and Tungyai Naresuan Wildlife Sanctuary. The least impacted areas were Luam Khlong Ngu National Park, Thong Pha Phum National Park and Chaleam Ratanakosin National Park. With a high risk to the wildlife community, law enforcement should be used in combination with a certain level of co-management with local communities.  相似文献   

17.
The Gallatin Petrified Forest of Montana, USA, is a unique resource. The extensive area of the fossil forests, the numerous petrified trees in upright positions, and the large number of vertical layers of “successive” forests are unparalleled in the world. Collection by permit is permitted, but damage to the petrified forest by indiscriminate collection occurs. To assess the impact, a comparative examination of replicate (over 13 yr) photography of selected specimens was undertaken. The amount of change over time, the possible cause of change, and the relationship of the location of the specimen to that amount of change were determined. It was found that although considerable loss continues, impacts prior to a 1973 collection policy were most severe. There was more loss by natural erosion than by collection, but the collections are additive to the natural changes. Size of petrified outcrops and the steepness of the slope on which they were found did correlate with the amount of natural change occurring over time. Human-induced change was associated with the distance of the outcrops from the main trailheads and the specimen size. This method provides a tool with which to monitor impacts and develop a future policy aimed towards conservation of a unique resource in light of the need for appreciative recreation and some specimen collection. Recommended changes in present management policy are provided.  相似文献   

18.
Effect of reservoir flushing on downstream river water quality   总被引:1,自引:0,他引:1  
The effect of short-term reservoir flushing on downstream water quality in the Geum River, Korea was studied using field experiments and computer simulations. The reservoir release was increased from 30 to 200 m(3)/s within 6 h for the purpose of this experiment. The flushing discharge decreased the concentrations of soluble nitrogen and phosphorus species considerably, but the experimental results revealed a negative impact on organic forms of nutrients and biochemical oxygen demand (BOD). A dynamic river water quality model was applied to simulate the river hydraulics and water quality variations during the event. The model showed very good performance in predicting the travel time of flushing flow and the variations of dissolved forms of nitrogen and phosphorus constituents. However, it revealed a limited capability in simulating organic forms of nutrients and BOD because it does not consider the re-suspension mechanism of these constituents from sediment during the wave front passage.  相似文献   

19.
ABSTRACT: The fate of contaminants in large water bodies is highly influenced by the transfer of flow and solutes across the water sediment interface. In this paper, an analytical model is presented where flow in both sediment bed and open channel is coupled at the interface through a boundary layer occupying the upper part of the sediment bed. The presence of this layer allows not only the capture of the inertia effects through a drag term in the generalized Darcy's equation, but also the specification of different soil parameters for the two porous zones. The flow is advective and driven by wave action along the water surface. The resulting system is solved for the pressure and flux in each sediment layer. The generated transport velocity fields are linked to a random walk simulation that is used to examine the trajectories of solute particles. Comparison of these trajectories against experimental tracer tests suggests a pattern very similar to the one attributed to the presence of surface mounds. The results clearly show the significance of the boundary layer and the drag term for soil with high permeability and the impact of both the thickness of the boundary layer and the length of the gravity wave relative to the depth of the water channel on the transport and exchange across the interface. The paper also examines the sensitivity of the mass exchange to the permeability of the two porous zones.  相似文献   

20.
The floatability of seven plastics (POM, PVC, PET, PMMA, PC, PS and ABS) in the presence of methyl cellulose (MC) and separation of plastics mixtures were investigated in this paper. It was found that the seven plastics can be separated into three groups by using the wetting agent MC. Group one includes POM and PVC. They are depressed at very low MC concentrations. Group two, including PET, PMMA and PC, has an intermediate floatability. Group three (ABS and PS) has a high floatability. They are almost not depressed within the given MC concentration range. In order to understand the mechanism of selective flotation of plastics and the chemical conditioning process, surface chemical factors, such as wettability of plastics and surface tension of flotation medium, and gravity factors, such as particle density and shape, were studied. It was found that the depressing effect of MC on plastics is ascribed mainly to its adsorption on the plastics surfaces. The MC molecules absorbed on plastics expose some of their polar groups oriented towards the aqueous phase, hence making the plastics surfaces hydrophilic. In addition, flotation selectivity for the plastics is dominated not only by wettability of plastics, but also by particle size, density and shape.  相似文献   

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