滑坡转化为泥石流机理研究综述

对国内外有关滑坡转化为泥石流的机理的研究做了全面的综述,重点介绍了国外最新的研究成果,阐明了今后研究的方向.滑坡转化为泥石流机理的研究,处于滑坡动力学与泥石流形成学的交叉点,既是学科的边缘问题,也是学科的前沿问题.滑坡转化为泥石流的过程是一个和土体液化密切相关的流态化过程,是土体和水体强烈相互作用的结果.滑坡直接转化为泥石流的机理的两个核心问题是超静孔压的产生和超静孔压的保持.Iverson对这一问题的研究直接促进了滑坡流态化理论的发展,并形成了最新的泥石流运动模型--库伦混合流理论,是对传统的基于流变关系的泥石流模型的重大突破.土体中粘性颗粒对滑坡直接转化为泥石流过程的影响,需要进一步进行研究.滑坡转化为沟谷泥石流是一个更为复杂的过程,是今后研究的重点.     

Conversion regular patterns of acetic acid, propionic acid and butyric acid in UASB reactor

On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used, the conversion regulations would have changed accordingly.Relationships of different substrates vary according to their locations. In the whole reactor, propionate‘s conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate‘s conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates‘ conversion. The ethanol-type fermentation of the acidogenicophase is the optimal acid-type fermentation for the two-phase anaerobic process.     

基于CE的不同流向下农地城市流转负外部效应研究

发展与保护的权衡是土地资源配置中难以回避的棘手问题。农地城市流转在为城镇化的快速推进提供土地要素的同时,却也在社会、生态方面引起一系列外部性损失,已有研究认为该损失的大小与农地城市流转的用途和周围环境有关,但并未进一步定量揭示其关联程度。鉴于此,本文将农地城市流转的去向归纳为住宅及商服用地、工矿仓储及交通运输用地、公共管理与公共服务用地三类,以武汉市和鄂州市作为研究区域,运用选择实验法(CE)以及多元Logit模型(MNL)识别了受访者对于农地城市流转负外部效应治理方案的偏好,从而间接测度了不同流向下农地城市流转负外部效应的经济总量,以期为实施农地城市流转的用途和规模管制提供依据。结果表明:1不同流向下农地城市流转产生的交通状况恶化、噪音污染、公共设施不足等七种类别负外部效应在类型和强度上有所差异;2绝大多数居民对治理农地城市流转的负外部性具有支付意愿,且在参与程度和参与强度(支付额)方面因农地城市流转的不同流向而有所区别,并且居民的受教育程度和家庭收入水平对选择效用的影响具有显著性且呈正相关关系;3不同流向下农地城市流转所产生的负外部效应的经济总量不容忽视,三种流向的负外部效应从大到小依次为农地流转为工矿仓储及交通运输用地、公共管理与公共服务用地、住宅及商服用地。因此,作为农地城市流转的管制主体,各级政府应当采用经济性管制与社会性管制并举的多样化管制手段对农地城市流转的用途和规模予以调控和管制。     

城市污水处理厂污泥直接热化学液化处理技术

污泥直接热化学液化技术是国外８０年代开始发展的一项污泥处理兼资源回收技术。它可使污泥中有机质的４０％以上转化为燃料油（热值≥３３ＭＪ／ｋｇ）,相应的有机碳转化率达到９０％左右。整个过程为一能量净输出过程。本文对其发展源流、研究现状和发展前景进行了综述和讨论。     

城市自来水中途生物性污染危险程度的预测研究

为了准确而又快速地预报自来水中途生物性污染的危险程度,防止介水传染病发生,本文对生活污水样品进行了大量的实验研究,同时收集和分析了国内历次污染事件资料。经大显筛选实验发现,水中氨氮是代表大肠菌群进行预测预报污染程度的最佳化学指标。发生污染事件的危险性可分为四级,相应的大肠菌群故分别为１００－、２００－、１０００－、１００００－。     

地面水中氨,硝酸盐,亚硝酸盐,氯化物,正磷酸盐,总硬度和硅酸盐的同时测定

用AQUA800辨别分析仪同时测定地面水中的氨、硝酸盐、亚硝酸盐、氯化物、正磷酸盐、总硬度和硅酸盐,是一种简便、迅速、准确、可靠的测定方法,样品无需预处理,精密度试验其变异系数分别为1．24％、2．18％、2．02％、2．67％、2．35％、3．57％、4．78％,加标回收率分别为103．5％、101．0％、95．0％、99．2％、97．6％、101．5％、98．0％,方法检测限分别为氨0．022mg／L,硝酸盐0．015mp／L,亚硝酸盐0．002tug／L,氯化物0．47mg／L,正磷酸盐0．015mg／L,总硬度17．6mg／L,硅酸盐0．55mg/L,能满足地面水中辨别分析仪同时测定氨、硝酸盐、亚硝酸盐点化物、正磷酸盐、总硬度和硅酸盐分析测定的要求。     

氨氮测量不确定度的评定

采用纳氏试剂光度法测定水质氨氮的测量不确定度评定,应该考虑工作曲线、测量重复性、标准溶液、仪器读数分辨率等对测量的影响.     

Remove cooking fume using catalytic combustion over Pt/La-Al2O3

Five monolithic catalysts with low noble metal content were prepared by irnmerge method （Pt/γ=Al2O3, Pt/La-Al2O3, Pt/YSZ-AI203, Pt＋Pd/La-Al2O3 and Pd/La-Al2O3） and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity （GHSV）. Some characterizations （XRD, TPR） were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application.     

Anaerobic digestion of dairy manure with enhanced ammonia removal

Poor ammonia-nitrogen removal in methanogenic anaerobic reactors digesting animal manure has been reported as an important disadvantage of anaerobic digestion (AD) in several studies. Development of anaerobic processes that are capable of producing reduced ammonia-nitrogen levels in their effluent is one of the areas where further research must be pursued if AD technology is to be made more effective and economically advantageous. One approach to removing ammonia from anaerobically digested effluents is the forced precipitation of magnesium ammonium phosphate hexahydrate (MgNH4PO4 x 6H2O), commonly called struvite. Struvite is a valuable plant nutrient source for nitrogen and phosphorus since it releases them slowly and has non-burning features because of its low solubility in water. This study investigated coupling AD and controlled struvite precipitation in the same reactor to minimize the nitrogen removal costs and possibly increase the performance of the AD by reducing the ammonia concentration which has an adverse effect on anaerobic bacteria. The results indicated that up to 19% extra COD and almost 11% extra NH3 removals were achieved relative to a control by adding 1750 mg/L of MgCl2 x 6H2O to the anaerobic reactor.     

Nitrogen Content of Letharia vulpina Tissue from Forests of the Sierra Nevada, California: Geographic Patterns and Relationships to Ammonia Estimates and Climate

Nitrogen (N) pollution is a growing concern in forests of the greater Sierra Nevada, which lie downwind of the highly populated and agricultural Central Valley. Nitrogen content of Letharia vulpina tissue was analyzed from 38 sites using total Kjeldahl analysis to provide a preliminary assessment of N deposition patterns. Collections were co-located with plots where epiphytic macrolichen communities are used for estimating ammonia (NH₃) deposition. Tissue N ranged from 0.6% to 2.11% with the highest values occurring in the southwestern Sierra Nevada (range: 1.38 to 2.11). Tissue N at 17 plots was elevated, as defined by a threshold concentration of 1.03%. Stepwise regression was used to determine the best predictors of tissue N from among a variety of environmental variables. The best model consisted only of longitude (r ² = 0.64), which was reflected in the geographic distribution of tissue values: the southwestern Sierra Nevada, the high Sierras near the Tahoe Basin, and the Modoc Plateau, are three apparent N hotspots arranged along the tilted north–south axis of the study area. Withholding longitude and latitude, the best regression model suggested that NH₃ estimates and annual number of wetdays interactively affect N accumulation (r ² = 0.61; % N ∼ NH₃ + wetdays + (NH₃ × wetdays)). We did not expect perfect correspondence between tissue values and NH₃ estimates since other N pollutants also accumulate in the lichen thallus. Additionally, other factors potentially affecting N content, such as growth rate and leaching, were not given full account.