防灾工程动态投资决策分析

本文应用最优控制理论对作者在文献[1]中所建立的两个防灾工程多变量动态投资决策模型进行了求解和理论分析。在一些基本符合工程实际的假设下得到了模型的解析解以及一些有意义的结果。     

清洁生产对加氢精制装置减污增效的重要作用

介绍清洁生产在长岭分公司加氢精制装置推行的背景、实施的主要方案、效果及持续清洁生产情况。     

辅助矿山救护队的建设工作应该加强

在现代煤矿里，灾害和事故仍然是不可避免的。采取减小组织内成员的自由度来强化专业救灾机构的整体功能固然重要，但非专业化的辅助矿山救护队的建设工作更应加强。因为他们亲临现场，熟悉灾情，又处于救灾的黄金时间里。因此，对是否酿成灾害和灾害中损失的控制问题，辅助矿山救护队有更多的优势。     

Purification and Properties of a Poly (β-hydroxybutyrate) Depolymerase From Penicillium sp.

An extracellular poly (β-hydroxybutyrate) (PHB) depolymerase was purified from a Penicillium sp. DS9701-09a by centrifugation, ultrafiltration, precipitation and gel filtration chromatography. The specific activity of the purified enzyme was 37.9-folds higher than that of the culture supernatant and the recovery yield was 11.8%. The PHB deploymerase molecular mass was 44.8 kDa from analysis of both Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Matrix-assisted laser desorption-time-of-flight (MALDI-TOF) mass spectrometer. The isoelectric point of 6.7 for the enzyme was determined by a two-dimensional electrophoresis. The optimum enzyme activity was observed at a temperature of 50 °C and pH 5.0. The apparent K _m of the enzyme was found to be 1.35 mg/mL. The PHB depolymerase consisted of 16 kinds of normal amino acids. The secondary structure of the enzyme was determined by CD spectrum. α-helix and β-turn were found to be 66% and 34% for the enzyme without ammonium sulphite. Chemical inhibition on the PHB depolymerase activity was examined and EDTA was found to have a significantly inhibitory effect.     

Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern China

Monitoring data from ozone（O3） automatic stations in three typical cities with different climatic areas in the southern and northern parts of eastern China are used to analyze temporal and spatial characteristics of ozone pollution at ground level. The results show that ozone pollution level has distinct regional differences and the concentration in the suburbs is higher than that in the urban areas. The seasonal variation of ozone concentration in different climatic areas is greatly affected by the variation of precipitation. Ozone concentration in Shenyang and Beijing , in the temperate zone, has one perennial peak concentration, occurring in early summer, May or June. Ozone concentration in Guangzhou, in sub-tropical zone, has two peak values year round. The highest values occur in October and the secondary high value in June. The ozone season in the south is longer than that in the north. The annual average daily peak value of ozone concentrations in different climates usually occur around 3 pm. The diurnal variation range of ozone concentration declines with the increase of latitude. Ozone concentration does not elevate with the increase of traffic flow. Ozone concentration in Guangzhou has a distinct reverse relation to CO and NOx. This complicated non-linearity indicates that the equilibrium of ozone photochemical reaction has regional differences. Exceeding the rate of Beijing＇s lh ozone concentration is higher than that of Guangzhou, whereas the average 8h ozone level is lower than that of Guangzhou, indicating that areas in low latitude are more easily affected by moderate ozone concentrations and longer exposure. Thus, China should work out standards for 8h ozone concentration.     

两种生物填料净化城市混合污水的对比分析

本文初步对软性、瑞琪两种填料净化城市混合污水的效果进行比较研究，为进一步深入开展土地快速渗滤技术及处理城市混合污水实用技术的研究提供依据。     

我国5A级景区最大承载量的空间分异

5A级景区最大承载量很大程度上反映出区域旅游资源的供给能力。通过对不同省市、不同类型旅游景区最大承载量的数理统计与空间展布,分析我国5A级景区最大承载量的省域空间差异和类型空间差异规律。结果表明:我国5A级旅游景区最大承载量空间分布不均衡,空间差异特征与人口分布规律较为一致;区域差异与类型差异可供景区规划布局和旅游者决策参考。     

长江白鱀豚的保护

白鱀豚是我国特有的珍稀淡水哺乳动物,仅分布于长江中下游,目前长江白鱀豚的种群数量仅约200头,濒临灭绝。造成白鱀豚濒危的主要威胁来自长江鱼类资源的减少、有害渔具的广泛使用、航运事业的发展、河道的大规模整治、水电工程的建设、水体污染以及白鱀豚自身的生理特征。通过我们多年的研究,提出了建立半自然白鱀豚保护区、人工饲养下白鱀豚的繁殖,和建立长江白鱀豚自然保护区等三大措施。在各级政府和科研部门的共同努力下,三项措施正在落实,为保护白鱀豚创造了良好的条件,但面临的困难还很多,任务十分艰巨,我们希望开展广泛的国际合作,为保护白鱀豚共同努力。     

Analysis of China''s Water Security and Virtual Water Trade

Producing goods and services all needs water consumption. The water used in the process of an agricultural or industrial product is called the "Virtual Water" contained in this product.Through international trade, water-scarce countries and regions could purchase water-intensive products--especially foods, from water-rich countries to balance their water deficits and achieve water safety. China is one of the 13 most water-deficit countries whose water safety have been severely challenged. This paper generalized the recent global research development and made a brief introduction about the methods calculating virtual water content in specific products. As a case study, we qualified China's annual virtual water flows from year 2000 to 2002 with trade in crops, and ended with some policy advice for application and practice of virtual water strategy.