新形势下对高等数学教学改革的思考

本文讨论了新形势下对高等数学教学提出的要求,以及原有的高等数学教学体系存在的矛盾,进而提出了对于高等数学进行教学改革的几点建议.     

硫／石灰石滤柱去除地下水中硝酸盐的研究

本文对硫／石灰石滤柱去除地下水中硝酸盐的工艺进行了报道。考察了滤柱的出水水质特性，并对滤料上附着的微生物进行研究。结果表明：①若硫／石灰石滤柱的进水浓度为２５ｍｇ／Ｌ（ＮＯ３－Ｎ），运行滤速为１．５ｍ／ｈ，则滤柱的运行周期为２１ｄ，在运行周期内，硝酸盐去除率高于９８％。滤柱穿透后，经反复冲洗，又很快恢复了运行。②滤柱滤料上存在大量的脱氮硫杆菌，其活菌数为１０８～１０９个／ｍＬ，异养反硝化菌的活菌数为脱氮硫杆菌的１／１０。滤料表面还存在少量的排硫杆菌，那不勒斯硫杆菌和硫酸盐还原菌、但不存在氧化硫硫杆菌等其它硫杆菌。     

应用AAP塔芯新技术改造冷却塔

介绍了洛阳石化总厂供水车间三循 2 # 冷却塔应用 AAP塔芯新技术改造情况 ,从运行观察和测试结果表明 ,改造后2 # 塔的水处理能力提高了 1 0 0 % ,经济效益显著。     

TBP-泡塑填料柱萃取回收铁钍渣浸出液中钍的研究

将ＴＢＰ固定在改性泡塑载体上，用于萃取回收铁钍渣硝酸浸出液中Ｔｈ４＋。试验表明：ＴＢＰ泡塑填料萃取分配比高，萃取容量大，当溶液硝酸浓度为４ｍｏｌ／Ｌ，接触时间１０ｍｉｎ时，萃余液中Ｔｈ４＋浓度小于００１ｍｇ／Ｌ，反萃液中Ｔｈ３＋浓度达８４ｇ／Ｌ，Ｆｅ３＋和Ｃｅ３＋浓度小于０１ｍｇ／Ｌ，萃取容量为ＴＢＰ泡塑填料１ｇ可萃取Ｔｈ４＋０２８ｇ；ＴＢＰ泡塑填料化学性质稳定，分相容易，能有效防止乳化现象。     

Designs with a priori information for nonmarket valuation with choice experiments: A Monte Carlo study

Good practice in experimental design is essential for choice experiments used in nonmarket valuation. We review the practice of experimental design for choice experiments in environmental economics and we compare it with advances in experimental design. We then evaluate the statistical efficiency of four different designs by means of Monte Carlo experiments. Correct and incorrect specifications are investigated with gradually more precise information on the true parameter values. The data generating process (DGP) is based on estimates from data of a real study. Results indicate that D-efficient designs are promising, especially when based on Bayesian algorithms with informative prior. However, if good quality a priori information is lacking, and if there is strong uncertainty about the real DGP—conditions which are quite common in environmental valuation—then practitioners might be better off with shifted designs built from conventional fractional factorial designs for linear models.     

TBP-泡塑填料柱萃取回收铁钍渣浸出液中钍的研究

将ＴＢＰ固定在改性泡塑载体上，用于萃取回收铁钍渣硝酸浸出液中Ｔｈ４＋。试验表明：ＴＢＰ泡塑填料萃取分配比高，萃取容量大，当溶液硝酸浓度为４ｍｏｌ／Ｌ，接触时间１０ｍｉｎ时，萃余液中Ｔｈ４＋浓度小于００１ｍｇ／Ｌ，反萃液中Ｔｈ３＋浓度达８４ｇ／Ｌ，Ｆｅ３＋和Ｃｅ３＋浓度小于０１ｍｇ／Ｌ，萃取容量为ＴＢＰ泡塑填料１ｇ可萃取Ｔｈ４＋０２８ｇ；ＴＢＰ泡塑填料化学性质稳定，分相容易，能有效防止乳化现象。     

填料气浮柱处理造纸废水的研究

采用填料气浮柱处理造纸行业纸机白水 ,通过对絮凝药剂碱式氯化铝的用量 ,废水进料表观流速、溶气水表观流速的大小 ,柱体回收段、分离段、浓缩段的深度和废水进料位置等因素的考察 ,表明在一定的条件下 ,该设备和工艺对降低废水CODCr和悬浮物含量 ,提高浮渣污泥固含量等指标具有明显的效果。同时 ,连续试验结果也说明该设备对降低废水BOD5 也有较好的作用。     

锦州湾水体中锌、铅、隔存在形式及分布规律的研究

本文研究了锦州湾海域水体中重金属锌、铅、镉各化学形态的含量及其各形态分布特征,其特征变化动态表明,该海域中重金属以可溶态为主要存在形式,其中以水合氧化物为重要清除载体.重金属除周边岩石风化物质的自然背景值外,主要来源于沿岸工厂排废.水体中重金属是在潮流水动力作用下,受各种理化因素的影响,产生迁移和转化.三种元素形态转化强度 Zn>Pb>Cd,它们污染程度为Cd>Zn>Pb.通过多元回归计算求得重金属与环境因素 pH 值(X_(PH))、Eh 值(X_(Eb))、氯度(X_(cl))、溶解氧(X_(DO))、化学耗氧量(X(COD))的多元一次方程.     

Some specialized risk assessment methodologies for vertebrate populations

We present three empirical methods for risk assessment in field studies of free-ranging vertebrates. First, we advocate statistical inference concerning population recruitment or mortality in response to ecological hazards. Second, if inferences about both recruitment and mortality are available, one can use a Leslie- Lefkovitch matrix to estimate the finite rate of population change () as a function of ecological hazards. Third, designed experiments can be conducted on samples of marked animals in natural environments to assess impacts and risks. These methods rely on either sophisticated capture-recapture or radio-tracking models, and on well-developed analysis theory. The use of uniquely marked animals is somewhat analogous to the use of tracers in other areas of risk assessment. We present examples of each approach and discuss some limitations.     

取代氮杂环类有机物水溶解度的估算与测定

本文采用一种修正的分子连接性指数研究了氮杂环类化合物水溶解度的定量结构性性质关系，这种修正的分子连接性指数是由原子半么取代原子的点价计算得来。逐步多元统计回归表明氮杂环的水溶解度和２阶及５阶原子半么分子连接性指数呈良好的相关性。