Gouging abrasion test for rock abrasiveness testing     

V.A. Golovanevskiy  R.A. Bearman 《International Journal of Mineral Processing》2008

Wear parts of many mineral processing and mining equipment are often subjected to high stress loads applied at high speeds and at varying angles of incidence, where the prevalent mode of wear is high-stress gouging/sliding impact abrasion. Examples include crusher liners, wear liners in hoppers and chutes, picks on roadheaders, discs on tunnel boring machines and ground engaging tools. Abrasion under these conditions is characterised by a high material removal rate and thus has a direct bearing on wear rates and service life of the equipment concerned. However, at present there appears to be no method for rock abrasiveness assessment under these conditions. This paper describes a new Gouging Abrasion method and apparatus for testing abrasivity of rocks under high-stress gouging/sliding impact wear. A Gouging Abrasion Index (Gi) is introduced, which can be used for prediction and assessment of component life expectancy and efficiency of mineral processing and materials handling equipment. Experimental data from Gouging Abrasion testing of numerous Australian rock types are presented. It is suggested that the results of Gi testing can be used for wear rate predictions for a variety of mineral processing and materials handling equipment working under high-stress gouging/sliding impact abrasion conditions.  相似文献   

沉积盆地有机质自由基热演化特征及其作为古温标的探索   总被引：1，自引：0，他引：1  

徐二社  邱楠生  秦建中  郑伦举 《地质学报》2008,82(3):413-419

恢复沉积盆地热历史的方法主要有古地温指标法和动力学模拟法两类.古温标法中最常用的为有机质成熟度和矿物裂变径迹,动力学模拟法中最常用的是盆地的拉张模型和挤压模型.本文针对Ⅰ型有机质自由基浓度作为沉积盆地古温标进行了探索研究.分析了自然演化系列Ⅰ型有机质的自由基的热演化特征;根据自然演化系列的Ⅰ型有机质自由基浓度及时间-温度指数(TTI)数据,对热模拟实验下的Ⅰ型有机质自由基浓度及时间-温度指数(TTI)值进行校正,由校正后的数据初步建立了Ⅰ型有机质的自由基浓度(Ng)与时间-温度指数(TTI)的定量模型.  相似文献   

Distribution of Cd,Pb, Zn and Cu and their chemical speciations in soils from a peri-smelter area in northeast China   总被引：2，自引：0，他引：2  

Ping Du  Nandong Xue  Li Liu  Fasheng Li 《Environmental Geology》2008,55(1):205-213

An exploratory study on soil contamination of heavy metals was carried out surrounding Huludao zinc smelter in Liaoning province, China. The distribution of total heavy metals and their chemical speciations were investigated. The correlations between heavy metal speciations and soil pH values in corresponding sites were also analyzed. In general, Cd, Zn, Pb, Cu and As presented a significant contamination in the area near the smelter, comparied with Environmental Quality Standards for Soils in China. The geoaccumulation index showed the degree of contamination: Cd > Zn > Pb > Cu > As. There was no obvious pollution of Cr and Ni in the studied area. The speciation analysis showed that the dominant fraction of Cd and Zn was the acid soluble fraction, and the second was the residual fraction. Pb was mostly associated with the residual fraction, which constituted more than 50% of total concentration in all samples. Cu in residual fraction accounted for a high percentage (40–80%) of total concentration, and the proportion of Cu in the oxidizable fraction is higher than that of other metals. The distribution pattern of Pb and Zn was obviously affected by soil pH. It seemed that Pb and Zn content in acid solution fraction increased with increasing soil pH values, while Cd content in acid soluble fraction accounted for more proportion in neutral and alkaline groups than acidic one. The fraction distribution patterns of Cu in three pH groups were very similar and independent of soil pH values. And the residual fraction of Cu took a predominant part (50%) of the total content.  相似文献   

A new method of estimating the ratio between in situ rock stresses and tectonics based on empirical and probabilistic analyses   总被引：1，自引：0，他引：1  

L.I. Gonzlez de Vallejo  T. Hijazo 《Engineering Geology》2008,101(3-4):185-194

This paper describes a new procedure for assessing the ratio between in situ stresses in rock masses by means of K (K = σ_H / σ_v, being σ_H and σ_v principal stress) and tectonics for purposes of engineering geology and rock mechanics. The method combines the use of the logic decision tree and the empirical relationship between the Tectonic Stress Index, TSI, and a series of K in situ values obtained from an extensive database. The decision tree considers geological and geophysical factors affecting stress magnitudes both on the regional and local scale. The TSI index is defined by geological and geomechanical parameters. The method proposed provides an assessment of the magnitude of horizontal stresses of tectonic origin. Results for several regions of Europe are presented and the possible applications of the procedure are discussed.  相似文献   

Participation in payments for ecosystem services: Case studies from the Lacandon rainforest, Mexico   总被引：3，自引：0，他引：3  

Nicolas Kosoy  Esteve Corbera  Kate Brown 《Geoforum》2008,39(6):2073-2083

Understanding people’s willingness to participate in projects and programmes of payments for ecosystem services (PES) has not been a key analytical concern of the scholarly literature around this new field of environmental policy and practice. This paper analyses participation in four communities benefiting from payments for biodiversity and carbon fixation in Mexico, and contrasts the results for each case with neighbouring communities that do not receive payments. We take a holistic approach that accounts for procedural rules, actors’ interactions, institutions and values, and individuals’ characteristics. We show that the nature of PES rules and the effectiveness of communication with government officers and NGOs influence resource managers’ ability and willingness to participate. We highlight community size, resource managers’ ability to diversify livelihood activities and local perspectives on the conservation of common forests, particularly sacred values and intergenerational concerns on forest conservation, as critical participation drivers. This analysis provides insights on why and how these new institutions may be attractive for some resource managers and permits to draw some recommendations for the future design of PES projects and programmes.  相似文献   

Drought and institutional adaptation in the Great Plains of Alberta and Saskatchewan, 1914–1939     

Gregory P. Marchildon  Suren Kulshreshtha  Elaine Wheaton  Dave Sauchyn 《Natural Hazards》2008,45(3):391-411

Agriculture in the southern Great Plains of Canada has been particularly vulnerable to prolonged episodes of drought. Using climate data and a precipitation minus potential evapotranspiration index, the extent of the region’s exposure to drought is examined. Between 1914 and 1917, the Dry Belt was particularly vulnerable to drought, whereas after 1928, a much larger region known as the Palliser Triangle covering most of southern Alberta and Saskatchewan was much more exposed to drought. These droughts provoked major institutional adaptation, in particular the establishment of the Special Areas Board by the Government of Alberta, and the creation of the Prairie Farm Rehabilitation Administration by the Government of Canada. Both organizations have proved to be relatively permanent public adaptations to the natural hazard of drought in the region. Moreover, these earlier experiences with prolonged drought as well as institution-building may be of value in helping the residents of the Palliser Triangle adapt to predicted climate changes in the future as well as anticipate some of the barriers to effective institutional adaptation.  相似文献   

Modeling households’ decisions on reconstruction of houses damaged by earthquakes––Japanese case study     

H. Sakakibara  H. Murakami  S. Esaki  D. Mori  H. Nakata 《Natural Hazards》2008,44(2):293-303

In this study, households’ decisions on reconstruction of damaged houses were modeled, using questionnaire data in Japan. Characteristics of households’ decisions were investigated using parameter estimation results. The effects of subsidizing policy were evaluated as follows. First, subsidy for rebuilding may be effective for the households whose houses were heavily damaged. Second, there is a possibility that subsidy accelerated rebuilding of houses by the households having children. Third, subsidy for rebuilding may not be effective for elderly people’s households and households in depopulated areas.  相似文献   

Biaxial test simulations using a packing of polygonal particles   总被引：1，自引：0，他引：1  

A. A. Peña  A. Lizcano  F. Alonso‐Marroquin  H. J. Herrmann 《国际地质力学数值与分析法杂志》2008,32(2):143-160

The mechanical response of cohesionless granular materials under monotonic loading is studied by performing molecular dynamic simulations. The diversity of shapes of soil grains is modelled by using randomly generated convex polygons as granular particles. Results of the biaxial test obtained for dense and loose media show that samples achieve the same void ratio at large strains independent of their initial density state. This limit state resembles the so‐called critical state of soil mechanics, except for some stress fluctuations, which remain for large deformations. These fluctuations are studied at the micro‐mechanical level, by following the evolution of the co‐ordination number, force chains and the fraction of the sliding contacts of the sample. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

松辽盆地三肇凹陷葡萄花油层成藏模式初探   总被引：11，自引：5，他引：6       下载免费PDF全文

孙雨  马世忠  刘云燕  刘宗堡  于利民 《地质科学》2008,43(4):746-757

运用源控含油气系统理论与综合分析技术,按成藏“层次分析”方法,通过对生、储、盖、圈(闭)静态要素及其内生、排、运、聚、散(失)动态过程的综合研究,对松辽盆地中央坳陷的三肇凹陷葡萄花油层成藏条件进行探讨,提出了以次级凹陷为中心、不同类型的油气聚集带紧邻并围绕次级凹陷最低部位呈环带状分布的大型凹陷内成藏模式,并进一步提出永乐次级凹陷中心及其三级聚油环带及徐家围子次级凹陷以西为"网式"运聚特征;在凹陷级成藏模式的指导下,通过对大面积密井网开发区综合解剖,提出三级构造带中单个的局部构造圈闭(群)、单个的(局部构造——)岩性圈闭(群)控油和成藏规律,为认识本区基本控油单元、油水分布规律、油气勘探及扩大新探区提供重要的理论依据。  相似文献   

饱和粉砂不稳定性的试验研究   总被引：3，自引：0，他引：3  

符新军  赵仲辉 《岩土力学》2008,29(2):381-385

通过对净砂和级配良好粉砂(含10 %粉土)进行一系列三轴固结不排水试验（CU）,研究了粉土、孔隙比和围压对饱和粉砂不稳定性的影响。试验结果表明,净砂与粉砂在不排水剪切条件下均会出现应变软化现象（即不稳定性）。同一围压下脆性指数(IB)随孔隙比增加,但不稳定线的应力比随孔隙比增加而减小。引用等效粒间孔隙比(ege)后,净砂和粉砂在ege-ln p?平面上拥有基本相同的临界状态线。在临界状态理论及等效粒间孔隙比的基础上,提出在同一修正状态参数(?ge)下净砂和级配良好粉砂有相似的不稳定性。  相似文献