Relationship between physicochemical properties and dewaterability of hydrothermal sludge derived from different source

Sewage sludge (SS) and deinking sludge (DS) were used to comparatively study the hydrothermal dewatering of sludge with different components. For a better overview, an insight into the relationship between physicochemical properties and dewaterability of hydrothermal sludge was provided. Results found that not all kinds of sludge were suitably conditioned by hydrothermal treatment (HT) in term of the elevation of dewaterability. Higher hydrothermal temperature tended to enhance the dewaterability of SS rather than DS, which was supported by the variation of their physicochemical properties (including water distribution, bonding energy, extracellular polymeric substance (EPS), particles size, acid functional groups and zeta potential in this study). In addition, the changes in surface morphology suggested that the reverse effect of HT on sludge dewaterability was mainly due to their dewatering behavior. For SS, the destruction of EPS structure leaded to the release of bound water, thereby strengthening sludge dewatering. Conversely, “Bridging effect” generated by lignocellulose in DS was beneficial for sludge dewatering; however, the increasing hydrothermal temperature degraded part of lignocellulose and weakened “bridging effect”, finally resulting in worse dewaterability of DS.     

基于JSP和Mysq1的环境监测网络数据管理

从环境监测数据管理的意义和重要性出发，介绍了环境监测网络数据管理系统，并给出了空气质量监测数据在系统中流程和计算处理的方法，实现了环境监测数据网络管理的功能，保证了空气质量数据传输的准确性和实时性。     

Atmospheric pollution in Beijing, China, as recorded in sediments of the Kunming Lake

The fluxes of heavy metals and magnetite, a fly-ash component, from coal burning, to sediments of the Kunming Lake in Beijing have increased measurably over the last fifty years. Ages were introduced to the sediment strata through Pb-210 geochronologies. Even with a doubling of coal usage by the year 2000, the anthropogenic metal fluxes will still be less than those recorded in metropolitan Tokyo and U.S. lakes.     

城市规划:走向"居住绿色革命"的途径

“城市规划”，对于现代人来说并不是陌生的词语。对于城市来说，好的设计则如繁花缀锦，是一个城市的细节，也是城市的文化积淀；建筑则如绿叶繁密，是城市的“点”，体现的是一座城市的个性。最重要的是规划，好的规划能够起到持续发展和有序扩张的作用，规划是城市的“面”、城市的“骨架”，更是城市的“灵魂”，好的规划能够让城市长盛、有序、美而有张力。因此，住得好、住得舒适的这场“居住绿色革命”，关键就是城市规划。     

对1976年陕西关中地震短期预报的反思

对1976年在陕西关中东部地区所发布的地震短期预报进行了回顾；对发布预报的前因后果进行了反思。     

Main results of strategic noise maps and action plans in Navarre (Spain)

According to Directive 2002/49, strategic noise maps and their correspondent action plans were carried out in the Autonomous Community of Navarre, Spain. Six strategic noise maps were produced for 120 km of major roads as well as a strategic noise map for the Agglomeration of the Region of Pamplona (ARP) with a population of 280,199 inhabitants. In the ARP, a total of 36,400 people (13.0 %) are exposed to Ln levels over 55 dBA and 42,300 people (15.1 %) are exposed to Lden levels over 65 dBA. With regard to major roads, a total of 3,900 people are exposed to Ln levels over 55 dBA and 2,400 people are exposed to Lden levels over 65 dBA. When designing action plans, different prioritisation criteria concerning rank-based effectiveness measures (mainly the amount of people benefitting from them) were taken into account.     

Use of cholinesterase activity in monitoring chlorpyrifos exposure of steer cattle after topical administration

The aim of this work was to study the pharmacokinetic behavior and the inhibitory effect of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities of chlorpyrifos (CPF) in steer cattle after pour-on administration. Determination of cholinesterase activity in plasma and erythrocyte was carried out according to Ellman kinetic method. CPF was analyzed by gas chromatography. AChE was the predominant form of cholinesterase analyzed, with low levels of BChE in plasma. Following the treatment with CPF, the maximum inhibitory effect on AChE or BChE were 50.88 ± 11.57 and 42.66 ± 12.01%, respectively. The chlorpyrifos plasma concentrations observed were low and they presented a high variability. Chlorpyrifos peak plasma concentration (10.42 ± 4.76 μ g/L) was reached at 8.42 ± 13.97 h. The pesticide was not detected in plasma after 48 h post treatment. The values of area under the curve (AUC) were 118.48 ± 87.46 μ g· h/L and mean resistance time (MRT) were 13.38 ± 10.41 h. The pour-on exposure to the organophosphate chlorpyrifos significantly reduced AChE and BChE activity in steer cattle and the recovery was not reached on 50 days post-treatment.     

Modeling Inorganic Aerosols and Their Response to Changes in Precursor Concentration in Mexico City

Abstract

Based on data from the 1997 Investigación sobre Materia Particulada y Deterioro Atmosférico-Aerosol and Visibility Evaluation Research (IMADA-EVER) campaign and the inorganic aerosol model ISORROPIA, the response of inorganic aerosols to changes in precursor concentrations was calculated. The aerosol behavior is dominated by the abundance of ammonia and thus, changes in ammonia concentration are expected to have a small effect on particle concentrations. Changes in sulfate and nitrate are expected to lead to proportional reductions in inorganic fine particulate matter (PM_2.5). Comparing the predictions of ISORROPIA with the observations, the lowest bias and error are achieved when the aerosols are assumed to be in the efflorescence branch. Including crustal species reduces the bias and error for nitrate but does not improve overall model performance. The estimated response of inorganic PM_2.5 to changes in precursor concentrations is affected by the inclusion of crustal species in some cases, although average responses are comparable with and without crustal species. Observed concentrations of particle chloride suggest that gas phase concentrations of hydrogen chloride may not be negligible, and future measurement campaigns should include observations to test this hypothesis. Our ability to model aerosol behavior in Mexico City and, thus, design control strategies, is constrained primarily by a lack of observations of gas phase precursors. Future campaigns should focus in particular on better understanding the temporal and spatial distribution of ammonia concentrations. In addition, gas phase observations of nitric acid are needed, and a measure of particle water content will allow stable versus metastable aerosol behavior to be distinguished.     

Theoretic model for the computer analysis of vehicle collisions

The complexity of the study and reconstruction of traffic accidents justifies the creation of tools which make easier the research in this area. That is the reason why the GIVET has developed a program called SINRAT III that lets, by means of dynamic simulation, reproduce the evolution of two vehicles in an accident in which a collision takes place, letting analyze the precollision and postcollision movements, as well as studying what happens during the contact and deformation of the vehicles in the collision stage. The simulation model is integrated by bodies developed using the bond-graph technique, that allows the simulation of the dynamic behaviour of the vehicles in any circumstance. At the end of this paper, an application example is presented, corresponding to an accident with collision between car and coach.     

对灾害研究中几个问题的思考

对灾害研究中有关的几个问题进行了探讨。认为： 灾害学是最重要的自然社会科学; 人文灾害比自然灾害更具毁灭性; 研究人文灾害中的公路交通事故、核战争问题、人口问题、环境污染问题等具有重要的现实意义和深远的历史意义。