洺河渡槽结构静力分析

Ming河渡槽的最大特点是输水流量巨大、体型庞大，它是南水北调工程中重要的输水建筑物。而以往在这方面的研究却很少，因此，对Ming河渡槽进行研究具有重要的现实意义。本文利用ANSYS软件对该渡槽进行结构静力分析，为工程实践提供理论依据和指导建议。     

洪水过程不确定性对泄洪风险影响的分析

重点分析了洪水过程的不确定性对泄洪风险的影响，并通过假设检验得到了洪峰削减系数的概率密度函数。以实际工程为例，利用蒙特卡洛法计算了考虑洪水过程不确定性的泄洪风险值，并与不考虑洪水过程的不确定性的计算结果进行了比较验证，结果表明后者的风险值明显大于前者，说明洪水过程不确定性对泄洪风险的影响是不可忽略的。     

排污权交易制度的经济理论分析及必要性

排污权交易是一种以市场为基础的经济刺激手段,排污权的卖方出售剩余排污权获得的经济回报,实质上是市场对其有利于环境的外部经济性的补偿;因削减污染的代价过高而不愿意削减的企业购买其必须排污的排污权,其支出的费用实质上是为其外部不经济性而付出的代价.因此排污权交易对实现环境外部性的内在化,加强治污环保技术的应用,促进环境产业化发展具有重要意义.要顺利实行排污权交易制度,必须建立起配套机制,如实施环境容量控制的排污许可证制度,排污指标商品化和价格化,排污权交易与其他防治污染的经济手段相结合.参6     

电晕场与介电分选提高水稻种子活力

为研究电晕场和介电分选对水稻种子活力的影响,该文利用弧形芒刺电极与下极板形成的电晕场对水稻种子在不同高压下进行处理,处理时间为4 min,结果显示,处理后水稻种子的活力有显著提高,并在17500 V （DC）时取得较优值;利用介电分选机在不同的分选电压下对水稻种子进行介电分选,选滚筒转速为25 r/min,结果发现,分选机对水稻种子有较好的分选效果,并且当分选电压为4000 V（DC）时,分选获得的 I 级水稻种子的活力最高。在上述最优条件下,先利用电晕场对水稻种子进行电晕场处理,再利用介电分选机对电晕场处理后的水稻种子进行介电分选,结果表明：水稻种子的各活力指标均高于只进行分选时的活力指标,其中Ⅱ级和Ⅲ级种子的活力指标有明显的提高,且Ⅱ级种子的活力指标较对照有显著提高（P＜0.01或0.05）,这也说明电晕场处理对低活力种子效果较好。同时,通过记录水稻种子每天的发芽数发现,电晕场处理和介电分选都能使水稻种子约提前1天发芽。这对后期研制电晕场与介电分选组合处理机提供了数据支持。     

Effect of land developmental process on soil solution chemistry in acid sulfate soils distributed in the Mekong Delta,Vietnam

Abstract

Water-soluble ionic substances in acid sulfate soils are likely to be strong controls for crop production and to have impacts on aquatic ecosystems. In dry seasons, in particular, oxidation of the soil surface followed by acidification probably produces lots of acids and soluble metals. To estimate acid and metal loads from acid sulfate soils to aquatic environments, we determined the composition of water-soluble ions from soils distributed in the Mekong Delta, Vietnam. At the end of the dry season, soils were taken from each soil horizon in two soil profiles on the delta under different land developmental processes. Water-soluble ions were extracted using both distilled water and artificially synthesized irrigation water (pH 6.3) adjusted to the same ionic strength and pH as the field canal water. The relationship between extracted basic cations in both extracts showed high linear correlation, indicating a similar extraction mechanism between both extractants. Higher ionic strength in the artificial irrigation water may not have any advantages for extraction by ion exchange and, thus, properties of extracts are likely to depend on the soil properties. The older the soil parent material, the larger the rates of soluble Al and Fe and the lower the pH. Progressive weathering of the soil on the older delta has already discharged greater amounts of bases, probably for compensation of acids, and the soil has started to release exchangeable Al sorbed onto negative-charge colloids and Fe from decomposed oxides. The soil profile of the older delta released relatively greater concentrations of Al with a lower content of base cations, where the annual averaged rice yield was half that of another site. Soluble metals and acids at both sites appear to accumulate in the upper horizons above the low permeable layer, which is probably widely distributed in the Mekong Delta.     

Experiment and analysis of an atmospheric DC glow discharge device

In order to reduce the volume and be used in portable instruments, a line-cylinder atmospheric glow discharge device with a 1.92 mm discharge gap is designed. It mainly consists of an inner line electrode and an outer cylinder electrode. The diameters of the line and cylinder electrodes are 0.16 and 4 mm, respectively. The transition from corona discharge to glow discharge is observed and explained. By using discharge waveform and photo, it has been verified that it is a glow discharge. The calculation methods of vibrational temperature and rotational temperature are deduced by use of the N2 second positive band system. The emission spectrum of the plasma is collected by spectrometer (Acton Spectrapro 2500i). From calculation, it is found that the vibrational temperature of the plasma is about 2 360 K and the rotational temperature of the plasma is about 830 K. The device is used as an ion source in the ambient mass spectrometer. The experiment results show that the plasma generated by DC glow discharge can well ionize the formic acid, acetic acid, and phenol, etc.     

基于产排污系数的木材工业排污量估算及污染负荷研究

以我国2011年污染源普查得到的产排污系数测算值和企业提供的离线监测数据为依据,对我国木材工业主要污染指标产排量系数进行对比分析;并结合我国近5年木材工业产品的产量,完成基于产排污系数的木材工业排污量核算及污染负荷评估.结果显示:1)我国木材工业产品污染物指标中,工业废气量和工业废水量的产排量比值大,污染控制效率低,而固体污染物排放率为零,处理效果好;2)不同产品排放的污染物在不同年度的排放量和污染程度为纤维板的工业粉尘及废气排放量最大,胶合板的工业废水排放量最大,刨花板污染程度相对较小;污染物中,工业废水排放量近5年增长最快,平均增加5倍以上;3)得出人造板行业与其他工业行业对比性实证数据,为人造板行业立身绿色环保产品提供佐证;4)通过对我国与发达国家污染物指标对比分析,为木材工业节能减排标准的制定及实现低碳发展提供依据.     

液化石油气最小静电点火能的测定

最小静电点火能是在静电引爆的所有条件都处于灵敏状态时引爆燃气的最小能量，测定最小静电点火能通常采用电容火花放电法。在一定的引爆电容下，测定液化石油气不同浓度下的点火能，并通过曲线拟合确定灵敏浓度，然后在该灵敏浓度下改变引爆电容，测出不同电容下的点火能，再通过曲线拟合确定灵敏浓度，然后在该灵敏浓度下改变引爆电容，测出不同电容下的点火能，再通过曲线拟合得出最小的引爆能量，即液化气的最小静电点火能，实验     

连续实时质谱法测定氮氢放电气流的瞬态成份

介绍一套自制放电装置，连续实时进样组件和改进过的色谱质谱联用仪进样接口件，实施连续实时地测定氮氢混合气体在高压、高电场强度条件下放电过程中的瞬态成份，重现性好。试验数据表明，连续实时进样质谱法适合研究放电气流（低温等离子体）的成份。     

沉沙池设计中恢复饱和系数α计算模型研究

分析论证了一维超饱和输沙法恢复饱和系数α与准静水沉降法修正系数K互为倒数;在分析影响α值变化主要因素的基础上,建立了计算恢复饱和系数α的数学模型;通过误差验证分析和经过几年生产设计部门的使用情况证明,模型的研究思路正确,精度、可靠度均满足设计要求,可供生产设计单位使用。