湖泊底泥中磷的存在形态与分布特征——以长春南湖为例

本文以长春南湖表层底泥为例,利用SMT法提取不同形态的磷,探索其分布规律.结果表明,底泥中TP以IP为主(占TP质量分数66.53%以上),OP次之;IP以Fe/Al P为主(占IP质量分数在53.55%以上),Ca-P次之.其中Fe/A-P和OP为活性磷组分(占TP质量分数在65.55%以上),易于释放到水体中,是水体营养化的主要影响因素,值得引起关注.就底泥中各形态P的时空分布而言,空间上有从四周向湖心减小的趋势,其中,西北、北部和南部边缘地带磷质量比较大;时间上,随时间波动,无明显一致性规律,其中,荷花池各形态磷的质量比最大值出现在9月,南湖大桥下各形态磷的质量比最大值出现在8月.究其原因,上述规律受气候和人为因素控制.研究成果为防治富营养化提供了理论依据.     

高校学生安全素质定量评价方法研究

本文通过运用层次分析法和发放调查问卷,对高校学生的安全素质进行分析,提出高校学生安全素质定量评价方法,并以首都经济贸易大学学生为实例进行应用研究,为高校的安全管理和校园安全文化建设提供参考。     

倒置A2/O工艺氮平衡与脱氮效率的分析

研究了倒置A^2／O工艺中的氮平衡和脱氮效率，并对影响脱氮效率的回流比和碳氮质量比进行分析。根据广州某城市污水处理厂水质特点，设计总回流比为3．0，其中污泥回流比为1．0，混合液回流比为2．0，理论总氮去除率为78．75％，实际运行总氮去除率达64．42％。     

钢铁工业含铁尘泥的资源化利用现状与发展方向

含铁尘泥是钢铁生产过程中从不同工艺流程的除尘系统中排出的含铁粉尘。这些尘泥回收后利用不当，不仅会造成环境污染，也是对含铁资源的巨大浪费。本文概述了钢铁工业含铁尘泥的综合利用现状，对瓦斯泥、转炉污泥、轧钢污泥、高锌含铁污泥、电炉粉尘等几类重点尘泥，提出了未来高附加值利用的方向。     

Analysis on Temporal and Spatial Changes and Driving Forces of Poverty-Stricken Areas in Hebei Province

1 INTRODUCTIONPoverty is a social phenomenon accompanying the processof human development (Shen Hong, 2000),it is also oneof the Three Ps problems (poverty, pollution andpopulation),alleviating and eliminating poverty has beenone of the major concerns in many countries. Since Chinesegovernment has implemented the anti-poverty programin a planned way in 1986, the number of impoverishedpopulation has decreased year by year, especially after theimplementation of National Seven-Year Anti-p…     

江苏土地资源存在的问题及其对策

一、扼要叙述土地资源利用现状、变化趋势和后备土地资源状况,二、说明江苏土地资源利用存在的问题。三、重点阐述人地矛盾突出和环境污染发展趋势严峻两大问题。四、指出必须把治理保护土地资源和生态环境作为一项重大任务加以落实。提出加强综合管理、综合治理,加强资源保护,控制人口增长,加速农业资源开发的对策。     

石羊河流域生态灌溉制度中的数学模型

本文从水利生态学的角度出发,研究分析了与水利有关的生态问题和与生态有关的水利问题。首次提出了生态灌溉制度的概念,为水利生态学的建立、水资源的高效利用打下了基础。建立了三级数学模型,用系统工程的方法,通过计算机求解,能够得到高效低耗的生态灌溉制度,为发展节水型的高效生态农业提供可靠的科学依据。     

Seismic monitoring and modelling of supercritical CO2 injection into a water-saturated sandstone: Interpretation of P-wave velocity data

This paper reports on an integrated laboratory and numerical simulation study of ultrasonic P-wave velocity response to supercritical CO₂ displacement of pore water in Tako sandstone. The analysis of dynamic velocity data recorded using an array of piezoelectric transducers mounted on a core sample showed that the P-wave velocities at different positions displayed a similar trend in time, i.e., an initial sharp fall followed by a more gradual decline. Considerable variations observed in the measured P-wave velocity reductions across the sandstone core could largely be attributed to the final state of saturation (e.g. uniform, patchy or in-between) attained by the two-phase fluids. Numerical simulation of the injection test using a simple 1D model was carried out to provide an estimation of the phase saturation changes underlying the measured P-wave velocity reductions. A second order polynomial correlation between the measured ultrasonic P-wave velocity reductions and the estimated CO₂ saturation was established. Comparison with the Gassmann velocities showed that the empirically established relationship marks a clear deviation from both the patchy and uniform saturation velocity curves.     

粮食粉尘爆炸事故树分析

运用事故树分析法分析了引起粮食粉尘爆炸的各种原因和环节,并由此建立了粮食粉尘爆炸事故树.通过事故树的结构重要度分析,提出了预防粮食粉尘爆炸事故的对策,同时给出了具体的预防措施.