Study on the Balance of Agricultural Water and Land Resources on Ningxia Plain

The article puts forward the process and means of regional water and land balance research, and then from two scenarios which are the balances under natural regulation and human intervention, calculated and analysed the balance between water and land on Ningxia Plain. For the balance under natural regulation named farmland water balance, using farmland water resource balance equation, the research estimated the monthly farmland＂ water balance of 8 major crops for all of the 12 counties on Ningxia Plain in the period of 1960-2001; for the balance under human intervention, the research estimated land-use water balance equation of the counties in 2000, and calculated the balance between land use and water resources including irrigating water of all the 12 counties on Ningxia Plain. Results showed that ①precipitation can not meet the water demand of the crops for growth and development on Ningxia Plain, and water shortage is the primary character of farmland water balance under natural regulation. ②the diversity of water and land balance of different counties is distinctly influenced by the crop structure, water quantity for irrigation and irrigation level. ③Irrigation water could meet the crop water demand on Ningxia Plain in 2000, but there was not much space to expand irrigating cultivated land.     

Changes Of Hydrological Environment And Their Influences On Coastal Wetlands InThe Southern Laizhou Bay, China

The structure and function of the coastal wetland ecosystem in the southern Laizhou Bay have been changed greatly and influenced by regional hydrological changes. The coastal wetlands have degraded significantly during the latest 30 years due to successive drought, decreasing of runoff, pollution, underground saline water intrusion, and aggravating marine disasters such as storm tides and sea level rising. Most archaic lakes have vanished, while artificial wetlands have been extending since natural coastal wetlands replaced by salt areas and ponds of shrimps and crabs. The pollution of sediments in inter-tidal wetlands and the pollution of water quality in sub-tidal wetlands are getting worse and therefore “red tides” happen more often than before. The biodiversity in the study area has been decreased. Further studies are still needed to protect the degraded coastal wetlands in the area.     

废水产氢产酸/同型产乙酸耦合产酸条件优化

为了更好地发挥产氢产酸/同型产乙酸耦合系统在废水厌氧发酵生产乙酸方面的优势,有必要寻找一种简单有效的方法以获得该系统产酸的优化条件.利用经过加热处理并活化的厌氧污泥作种泥,以模拟废水中的葡萄糖为底物,针对发酵时间、底物浓度、种泥浓度、初始pH进行4因素10水平均匀设计实验,得到了乙酸生产指标与产酸条件之间关系的回归方程;也得到了以高乙酸产量为主要目标导向同时兼顾高乙酸产率和高乙酸生产强度目标的优化条件;优化条件实验乙酸浓度比均匀设计中最高乙酸浓度提高20%左右.研究表明,将均匀设计应用于废水产氢产酸/同型产乙酸耦合产酸条件优化,可以避免盲目性,迅速获得满意结果.     

伞罩型除尘脱硫塔内除雾器性能研究

除雾器是湿法烟气脱硫(WFGD)系统内重要的设备之一,其性能对WFGD系统运行的可靠性有重要影响.利用Fluent6.2软件对新型伞罩型除尘脱硫塔内的三维两相流场进行数值模拟,气相采用RNG湍流模型,液相采用离散相模型,选择SIMPLE算法进行计算,分析塔内的折板除雾器和旋流板除雾器的速度场、压力场和液滴的分布情况.结果表明,烟气经过折板除雾器,产生了明显的压降,且在拐角区域湍流耗散强烈,是实现气液分离的关键区域;烟气经过旋流板除雾器,速度和压强分布具有良好的对称性,液滴被气流旋转抛向壁面实现气液分离.模拟结果对新型的WFGD除雾器的设计和运行具有一定的理论指导意义.     

建筑火灾烟流运动特性网络模型的求解收敛性

分析了运用网络模型模拟建筑火灾烟流的计算过程，通过总结影响网络模型求解精度及收敛性的关键因素，改进了原烟流预测软件对建筑物各开口的净、正、负质量流量的算法。改进后的模型消除了振荡效应，模拟结果曲线平滑稳定，实现了运用网络模型对多室建筑物烟流特性的模拟计算。     

超临界CO2回收线路板工艺研究

采用正交试验设计进行了超临界CO₂回收废弃印刷线路板的实验。以温度、压强、时间和夹带剂为实验因素，通过对实验前后样本在重量、厚度、弯曲强度和断裂强度四方面变化的分析考察了各实验因素对实验效果的影响。实验结果表明，影响超临界CO₂法回收印刷线路板的最主要因素为温度、时间和夹带剂，超临界CO₂法回收废弃印刷线路板的最佳工艺条件：温度270℃，压强大于7.38 MPa，时间3 h，夹带剂(水)160 mL。实验进一步验证了压强对实验结果的非显著性影响。     

优势菌的筛选及其强化活性污泥好氧反硝化的研究

利用含活性污泥提取物的贫培养基筛选SBR系统中的好氧异养优势菌。结合自然温度（15～20℃）、延长培养时间等条件来提高菌群的可培养性。从SBR活性污泥系统中分离出5种细菌。4株去除COD优势菌，1株异养硝化细菌，能在好氧条件下实现对总氮的去除。反应池底采用边缘对称曝气，反应池内细菌在时间顺序和空间位置上循环经历好氧过程及微氧过程。将PVA铝盐法固定的细菌对反应器进行生物强化。结果显示，在好氧工艺的条件下，投加优势菌群后，与未加优势菌群的反应器相比，可以显著改善污泥的沉降性能，COD、NH₃-N和TN降解率显著提高，分别达到98%、97%和90%。生物强化作用明显，反应器内具有良好的好氧反硝化环境。     

TiO2-xNx光催化氧化苯甲酸的研究

采用悬浮态光催化反应体系，以氙灯为光源，自制纳米TiO2-xNx为催化剂，考察了苯甲酸光催化氧化过程中TiO2-xNx质量浓度、反应体系初始pH和苯甲酸初始质量浓度对苯甲酸溶液中TOC去除率的影响。实验结果表明：最佳催化剂质量浓度为0．30g／L；TiO2-xNx的等电点为pH=5．3，在酸性条件下（pH=2．0）更有利于苯甲酸在催化剂表面的吸附，以及光生电子与O2反应生成·OH的进行；随苯甲酸初始质量浓度增加，TOC去除率降低，反应速率也相应地降低。TiO2-xNx比P25型TiO2表现出更强的浓度适应能力。     

社会和谐与可持续发展

本文运用系统科学原理阐释了社会和谐的内涵,指出社会和谐须以人与自然和谐为基础,以人与人之间的平等、友爱和同合作为表征,其构建与实现应遵从人类社会的演化规律,依赖予在把握人类社会需求演绎、协同人与自然关系的基础上推动生产力的高效有序发展和自然资源、生态环境的可持续支持.进而从可持续发展角度,提出了人与自然和谐的"双剩余理论",以揭示其间的供瓣枧理和协同准则;推导出了社会收益分配的相对公平系数,以衡量人与人公平要求下的社会和谐.针对国情和战略目标要求,提出了以加强小城镇建设为轴心的城市、小城镇与农村人流、物流、财流和信息流合理聚散的"三元结构"发展模式,以促进我国和谐社会的建设和可持续发展战略的有序实践.