矿产资源资产负债表编制技术框架初探

矿产资源资产负债表编制技术框架的探讨对于推进我国不可再生资源资产负债表编制技术的形成、指导我国不可再生资源的科学开发并落实自然资源资产离任审计制度有着明确的实际意义。本文在国际通用的环境与经济综合核算体系的基础上,探索性的提出了矿产资源资产负债表的编制技术框架(以下简称框架)。该框架以实现国家矿产资源资产摸底和官员环境绩效评估为目标,函括了矿产资源资产负债表的编制原则,资产负债表的会计主体、会计要素、相关交易和事项的具体指向,资产负债表的实物量账户和价值量账户的内容和归类,矿产资源资产负债表的具体编制流程,以及矿产资源资产负债表示意等内容。具体而言:首先,本框架指出了矿产资源核算应坚持复式记账原则和权责发生制原则;其次,框架明确了会计主体为矿产资源的所有者(即政府),会计要素中的资产指的是由政府辖区控制的矿产资源,负债指的是政府开采矿产资源过程中从生态系统中"借"的其他自然资源(比如水资源、能源资源等)和生态服务(清洁的空气、水循环、气候调节等),这是本框架区别于传统国民经济核算的核心所在;再次,框架确立了矿产资源开采涉及的六大相关交易和事项,并据此设立了五类实物量账户和三类价值量账户,其中特别构建了集"生态系统服务"、"环境污染"和"资源消耗"三位于一体的"生态成本"和"生态负债"账户;最后,框架根据矿产资源开采的六大相关交易和事项,以及明确的以资产、负债与所有者权益为区分的会计账户,具体展示了矿产资源资产负债表的具体编制流程,并形成了最终的资产负债表示意。除此之外,本框架还提供了如何将实物类账户价值化的方法,特别提出了可用资源租金的净现值方法测度没有直接市场价格的非生产性资产的当前价值。该框架虽然是以矿产资源为研究对象,但其基本思路和技术也适用于其他不可再生资源的资产负债表编制。     

基于水质污染风险识别的人工湖需水研究

人工湖需水量是指维持湖区水量平衡、满足人工湖水质目标的供水量,人工湖需水量确定是人工湖水体工程设计的主要内容之一。以上虞滨海新城建设的人工湖为例,分析了人工湖建成后的可能污染源,采用TP质量守恒模型,预测了不同生活污水截污率、生态措施作用前后的人工湖需水量及水质要求。结果表明,当生活污水截污率为100%时,若供水TP≤0.10mg/L,则人工湖需水量为240万t/a;当生活污水截污率为95%时,若供水TP=0.05mg/L,不考虑生态措施作用,则人工湖需水量为1 600万t/a;当生活污水截污率为95%时,若供水TP=0.05mg/L,在生态措施作用下人工湖需水量为730万t/a。     

Simultaneous nitrification and denitrification in step feeding biological nitrogen removal process

The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates.Biological occunenee of simultaneous nitrification and denitrification was verified in the aspect of nitrogen mass balance and alkalinity.The experimental results also showed that there was a distinct linear relationship between simultaneous nitrification and denitrification and DO concentration under the conditions of low and high aeration flow rate.In each experimental run the floc sizes of activated sludge were also measured and the results showed that simultaneous nitrification and denitriflcation could occur with very small size of floc.     

Ammonia volatilization losses and balance from urea applied to rice on a paddy soil

Ammonia volatilization loss and 15N balance were studied in a rice field at three different stages after urea application in Taihu Lake area with a micrometeorological technique. Factors such as climate and the NH4+-N concentration in the field floodwater affecting ammonia loss were also investigated. Results show that the ammonia loss by volatilization accounted for 18.6%-38.7% of urea applied at different stages, the greatest loss took place when urea was applied at the tillering stage, the smallest at the ear bearing stage, and the intermediate loss at the basal stage. The greatest loss took place within 7 d following the fertilizer application. Ammonia volatilization losses at three fertilization stages were significantly correlated with the ammonium concentration in the field floodwater after the fertilizer was applied. 15N balance experiment indicated that the use efficiency of urea by rice plants ranged between 24.4% and 28.1%. At the early stage of rice growth, the fertilizer nitrogen use efficiency was rather low, only about 12%. The total amount of nitrogen lost from different fertilization stages in the rice field was 44.1%-54.4%, and the ammonia volatilization loss was 25.4%-33.3%. Reducing ammonia loss is an important treatment for improving N use efficiency.     

高水分垃圾焚烧热回收和烟气净化系统的合理布置

用热平衡计算分析了高水分生活垃圾在焚烧前干燥脱水对系统热效率的影响 ,并比较了用不同介质干燥湿垃圾时热回收系统的效率和对烟气净化系统布置的要求。计算表明 :系统产生的可供有效利用的蒸汽量总是随垃圾干燥后应用基水分的降低而上升。采用排烟作为干燥介质时系统热效率也随应用基水分的降低而上升 ;而采用热空气作干燥介质时 ,计算热效率有轻微的下降。采用垃圾干燥应对烟气净化系统进行合理布置。     

厌氧发酵系统温度的选择和热量平衡

本文分析了厌氧发酵温度的选择和厌氧系统中热量平衡的关系。并运用此关系对薯干酒糟过滤液在冬季最低温度为0℃,夏季最高温度为35℃的地区进行中温和高温厌氧发酵处理中的热量平衡关系分别进行了讨论,证明了对温度为50℃,COD浓度为23g/L的废液进行中温发酵能得到更大的经济效益,但也必须使用所产生的沼气作为能源加热或冷却废液。所需的热量和气温的关系为:Q_t=4.73×105to-3.73×106 (KJ/d)。      

变频调速技术对锅炉给水泵安全运行的影响

分析给水泵变频调速节能原理;针对锅炉给水泵改由变频器控制后存在的汽蚀及平衡盘磨损等问题进行了深入的研究,并提出了解决办法.     

粉煤灰浸出液入渗土壤过程中的水岩作用研究

为明确粉煤灰浸出液对地下水环境的影响,依据饱水土柱试验,利用质量平衡模型,对比研究了灞桥电厂粉煤灰浸出液和清水入渗土壤过程中的水岩作用.研究表明,虽然粉煤灰浸出液和清水入渗土柱的渗出液水化学特征存在明显差异,但入渗水的水质对渗出液的时间变异性影响较小.矿物的溶解沉淀作用及Ca-Na离子交换等水岩作用对浸出液和清水入渗过程中的化学反应及水化学形成产生重要影响.高浓度的粉煤灰浸出液比清水溶解了土壤中更多的可溶盐,使土壤的渗透系数增大,增加了地下水污染风险.     

Simulation of Nitrogen Dynamics in Soil Using Infocrop Model

Nitrogen is the most widely used fertilizer nutrient, and it is a universally deficient nutrient too, which often severely restricts the growth and yield of crops. To improve N fertilizer management, soil–plant system models can be applied to simulate adequate N supply for both, optimal crop growth and minimal N losses. The likely impact of climate change on the cereal production is of paramount importance in the planning strategies to meet the future growing needs on sustainable grounds. In this scenario models are the effective tools to foresee the probable impacts and for choosing appropriate land use options. The study reported in this thesis, employs field experiments and use of simulation tools to understand the dynamics of soil N balance and relate growth and yield of rice under varying nitrogen inputs. The InfoCrop model was used in this study, which was calibrated with the historic data sets, and subsequently validated with the field experiment conducted at IARI Farm, New Delhi. Simulated results matched well with the observed values in terms of growth and yield of rice and seasonal nitrogen uptake. The components of soil nitrogen balance differed among varying nitrogen level treatments, which was also captured by use of InfoCrop. The model was then taken to climate change impact analysis. The results clearly revealed that when temperature increased, the soil N losses, like denitrification, volatilization, N2O emission increased, whereas grain and biomass yields decreased. The further scope of the study is to validate the study in contrasting agroenvironments.     

Evaluation of the STP model: comparison of modelled and experimental results for ten polycyclic aromatic hydrocarbons (PAHs)

Screening level risk assessment models are used by many countries to assess the treatability of organic chemicals during the sewage treatment process, especially those that are new to commerce. The performance of one such model, the sewage treatment plant model, is evaluated in the current study by comparing model predictions with actual measurement data collected at various stages of a typical full-scale activated sludge type sewage treatment plant. A suite of ten polycyclic aromatic hydrocarbons (PAHs) with widely varying physico–chemical properties were monitored for the comparison. Model predicted removal efficiencies were in very good agreement with those measured for all ten PAHs. Observed chemical concentrations and their trends at various stages of the sewage treatment process were also well simulated by the model. Results also suggest that a reasonable first approximation estimate of a range for the biodegradation half-life needed for the model may be obtained by dividing reported aqueous biodegradation half-life by scaling factors of 50 and 150.