气瓶内附油脂充氧过程爆炸实际油脂量计算

通过热力学计算,充氧12 MPa时,导致氧气瓶爆炸需要的最小油脂量为66.4~79.6 g。同一气瓶在不同的充装压力下发生爆炸,所需要的最小油脂放热量不同,即所需要的油脂量不同。同一气瓶充装压力越高,瓶内的气体压缩能越高,导致气瓶爆炸所需要的最小油脂量就越少。实际求解碎片运动的动力学方程,得到碎片的初动能Ek,并推断气瓶实际爆炸能量。     

低压液化气体钢瓶＂满液＂爆炸压力变化分析

本文对低压液化气体钢瓶“满液”爆炸的特征及内部压力变化了进行了理论分析和举例计算,并就如何安全使用液化气体钢瓶提出了一些合理化建议,希望能对气瓶的安全使用起到一定的警示作用。     

硫酸盐腐蚀作用下膏体充填材料蠕变特性研究

为研究硫酸盐腐蚀后膏体充填材料的蠕变特性,采用饱和的Na2SO4溶液对充填体进行腐蚀试验,并对各个腐蚀时间不同的充填体采用TAW2000型岩石三轴试验机进行三轴蠕变试验。根据试验数据建立膏体充填材料的蠕变本构模型,将一个应变触发的非线性粘壶串联到Burgers模型上,建立满足充填体蠕变特性的改进Burgers模型,并推导其一维和三维蠕变本构方程。研究结果表明:在硫酸盐腐蚀作用下,充填体的蠕变变形在腐蚀6d时出现了一定的减少,但随着腐蚀时间的推移蠕变变形明显加大,在应力较大时出现了加速蠕变并导致试件破坏,硫酸盐腐蚀作用严重影响了充填效果;建立的改进的Burgers模型与试验数据基本吻合,能够反映腐蚀后充填体蠕变规律。     

残采区多形态废巷注浆综合治理技术

针对海天煤业井田范围内存在大量废巷问题,通过现场调研、钻孔窥视、理论分析等方法研究了废巷的存在形式,依据废巷的特点将其归纳为完整型与冒落型两种形式。基于此研究了治理方案,提出针对完整型废巷的地面建站注浆充填工艺与针对冒落型废巷的井下移动式注浆加固工艺,并分别提出与之相适应的注浆材料,即粉煤灰基材料与新型双液材料。工程实践表明:地面建站充填工艺治理完整型废巷效果较好,系统制浆能力可达60 m3/h,并能够实现自动化控制。井下移动式治理工艺对于冒落型废巷具有较强的适应性,可以解决冒落区的成孔难与漏浆问题。通过对以上两种类型废巷注浆治理后,工作面推进均较为顺利,没有出现影响工作面正常生产的顶板、瓦斯问题。     

Simulating regeneration and vegetation dynamics in Mediterranean coniferous forests

This study aims to provide a quantitative framework to model the dynamics of Mediterranean coniferous forests by integrating existing ecological data within a generic mathematical simulator. We developed an individual-based vegetation dynamics model, constrained on long-term field regeneration data, analyses of tree-rings and seed germination experiments. The simulator implements an asymmetric competition algorithm which is based on the location and size of each individual. Growth is parameterized through the analysis of tree-rings from more than thirty individuals of each of the three species of interest. A super-individual approach is implemented to simulate regeneration dynamics, constrained with available regeneration data across time-since-disturbance and light-availability gradients. The study concerns an insular population of an endemic to Greece Mediterranean fir (Abies cephalonica Loudon) on the island of Cephalonia (Ionian Sea) and two interacting populations of a Mediterranean pine (Pinus brutia Ten.) and a more temperate-oriented pine (Pinus nigra Arn. ssp. pallasiana) on the island of Lesbos (NE Aegean Sea), Greece. The model was validated against plot-level observations in terms of species standing biomass and regeneration vigour and adequately captured regeneration patterns and overall vegetation dynamics in both study sites. The potential effects of changing climatic patterns on the regeneration dynamics of the three species of interest were subsequently explored. With the assumption that a warmer future would probably cause changes in the duration of cold days, we tested how this change would affect the overall dynamics of the study sites, by focusing on the process of cold stratification upon seed germination. Following scenarios of a warmer future and under the current model parameterization, changes in the overall regeneration vigour controlled by a reduction in the amount of cold days, did not alter the overall dynamics in all plant populations studied. No changes were identified in the relative dominance of the interacting pine populations on Lesbos, while the observed reduction in the amount of emerging seedlings of A. cephalonica on Cephalonia did not affect biomass yield at later stages of stand development.     

Competitive Displacement of Trees in Response to Environmental Change or Introduction of Exotics

Various global change factors such as natural and anthropogenic climate change, tropospheric ozone, CO₂, SO₂, and nitrogen deposition affect forest growth, but in species-specific ways. Since even small differences in growth rates between competing species can lead to eventual competitive exclusion, it is important to know the rate at which displacement might occur. Similarly, invasive species may displace native species and cause their extinction. A simulation study of displacement velocity was conducted. Competitive displacement between pairs of similar tree species in which one species has a growth advantage produced trajectories that fit an exponential decay model, leading to the use of the half-life as a useful summary statistic. At any given level of growth differential, the half-life for shade-tolerant species was found to be much longer than for shade-intolerant species due to the ability of shade-tolerant species to survive even when their growth is very slow. Trees with longer life-spans also persisted longer, but this effect was weaker than the shade-tolerance effect. Disturbances speeded up displacement by increasing turnover. For short-lived, intolerant species with a 20% disturbance rate and 20% growth suppression, the estimate of an 100-year half-life could be considered a precipitous rate of decline, with a risk of extinction at about 500 years. In the absence of disturbance, and with a 20% growth reduction or differential between competing species, half-lives for species replacement ranged from 100+ to nearly 800 years. With lesser growth differentials, half-lives are much longer. Such gradual competitive displacement processes will be very difficult to detect in the field over periods of even decades. Results of this study have implications for exotic species invasions. It is predicted that intact forest is not truly resistant to invasion, but that invasion of shade-tolerant tree species should be very slow. Invasion of shade-intolerant species is predicted to be accelerated by disturbance, as has been frequently observed. Results of the simulations were supported by data compiled from several parts of the world.     

煤矸石井下填充后微生物降解残渣的分析

通过对煤矸石进行微生物降解试验,探讨煤矸石并下填充的可行性并为填充后的污染控制提供理论依据。试验结果表明：煤矸石中有机质可以被微生物降解,浸泡和接种物驯化有利于微生物降解有机质,而且接种物含量和浸泡时间影响残渣中金属Ag、Cu、CO和Fe的含量;试验后残渣中CaO、MgO、SiO2不会对地下水造成太大影响,但残渣中Fe2O3含量相对较大,将可能引起地下水中Fe超标,可能对地下环境有一定的影响。     

江西潭坑铅锌(银)矿床特征及成因分析

江西省潭坑铅锌(银)矿区位于北武夷铅锌银成矿带内,本文系统阐述了矿区地质和矿床特征,并对矿床的成因进行了探讨。认为本区铅锌(银)矿床,经历了火山喷发沉积和后期热液充填两大成矿期,与次火山岩体(流纹斑岩)有密切的关系,属次火山热液矿床。     

Coupling of zero valent iron and biobarriers for remediation of trichloroethylene in groundwater

This study attempted to construct a three series barrier system to treat high concentrations of trichloroethylene (TCE; 500 mg/L) in synthetic groundwater. The system consisted of three reactive barriers using iron fillings as an iron-based barrier in the first column, sugarcane bagasse mixed with anaerobic sludge as an anaerobic barrier in the second column, and a biofilm coated on oxygen carbon inducer releasing material as an aerobic barrier in the third column. In order to evaluate the extent of removal of TCE and its metabolites in the aquifer down gradient of the barrier system, a fourth column filled with sand was applied. Residence time of the system was investigated by a bromide tracer test. The results showed that residence time in the column system of the control set and experimental set were 23.62 and 29.99 days, respectively. The e ciency of the three series barrier system in removing TCE was approximately 84% in which the removal e ciency of TCE by the iron filling barrier, anaerobic barrier and aerobic barrier were 42%, 16% and 25%, respectively. cis-Dichloroethylene (cis-DCE), vinyl chloride (VC), ethylene and chloride ions were observed as metabolites following TCE degradation. The presence of chloride ions in the e uent from the column system indicated the degradation of TCE. However, cis-DCE and VC were not fully degraded by the proposed barrier system which suggested that another remediation technology after the barrier treatment such as air sparging and adsorption by activated carbon should be conducted.     

半水磷石膏充填体离子固化与尺寸效应

针对磷石膏堆存所产生的环境污染问题,提出以无害化处理后的半水磷石膏（HPG）作为矿山充填材料的解决方案.以渗透试验、物性测试试验和化学成分测定等试验为基础,研究了HPG在不同石灰掺量、不同尺寸、不同养护龄期条件下的毒性浸出和浸泡离子析出规律.结果表明,石灰添加量为2%时,HPG中的P、F等潜在有害元素固化效果最好,所制备的充填体试块3d单轴抗压强度可达7.4MPa;其抗渗透性相对于未添加石灰的HPG提高3000倍以上.通过浸泡实验测定了HPG在去离子水中的单位面积溶出速率,得出了暴露面积为4m²时充填体中P、F、Ca²⁺、SO₄^2-离子日均析出总量,分别为0.84、0.32、27.84、89.32g;同时发现HPG试块的离子析出具有尺寸效应,相同浸泡时间、固液比条件下,增大充填体尺寸可以减小离子析出速率.