焚烧麦杆对稻田CH4 和N2O 排放的影响

采用3 种麦杆处理方式(不还田、均匀混施和原位焚烧)进行田间试验,观测稻田CH₄ 和N₂O 的排放情况,以探讨原位焚烧麦杆对稻田CH₄ 和N₂O 排放的影响.结果表明,与不还田处理相比,原位焚烧显著增加稻田CH₄ 排放量,同时显著减少稻田N₂O 排放量;与均匀混施处理相比,原位焚烧显著减少稻田CH₄ 排放量,二者的N₂O 排放量无明显差异.     

生活垃圾焚烧飞灰及其稳定化产物的长期浸出行为

采用柱浸出实验方法,考察了飞灰、磷酸盐稳定和自然老化稳定后飞灰的长期浸出特性.结果表明:灰样浸出液的pH值从初始的较低值快速上升到较高值后趋于稳定,3种飞灰都有较强的酸中和能力;Ca的浸出浓度远高于Pb,Cd,Zn,Cr和Ni等重金属,在浸出初期甚至达到100g·1-1以上;重金属均呈现初期快速溶出的现象;对比稳定化处理前后飞灰的柱浸出实验结果,表明磷酸盐稳定及自然老化稳定后飞灰具有更好的长期稳定性;对比柱浸出实验和国标GB5086.1-199r7的浸出结果,表明后者可能低估了稳定后飞灰处置初期重金属的浸出风险     

The Time Invariance Principle,the absence of ecological chaos,and a fundamental pitfall of discrete modeling

This paper is to show that most discrete models used for population dynamics in ecology are inherently pathological that their predications cannot be independently verified by experiments because they violate a fundamental principle of physics. The result is used to tackle an on-going controversy regarding ecological chaos. Another implication of the result is that all dynamical systems must be modeled by differential equations. As a result it suggests that researches based on discrete modeling must be closely scrutinized and the teaching of calculus and differential equations must be emphasized for students of biology.     

土氟静态吸附特性及其影响因素

采用室内试验方法,研究了4种土对氟的静态吸附特性及其影响因素.结果表明:四种土的吸附性能与氟质量浓度的关系用回归方程拟合达极显著的直线正相关水平,土吸附系数差异,表现为中沙<粉土<粉质粘土<粘土.此外,土吸附氟后的平衡溶液pH值随氟加入质量浓度增大而上升,主要是氟与OH-发生交换吸附作用;干扰因素试验中,HCO3对氟吸附有重要影响,随其质量浓度增加而减少,CR、S042-表现不明显;pH值因素试验中,氟的吸附性能随pH值先增加后下降,原因是酸碱条件影响了氟的存在形态,导致土氟吸附性能发生变化.     

土地利用变更的土壤及地下水污染调查方法及实例

以南京大厂区某地块的土壤及地下水污染调查为实例,提出了资料收集、源项分析、监测因子筛选、监测布点．场地地质水文勘探和土壤及地下水采样分析的土壤及地下水污染调查方法,探讨了评价标准和确定土壤及地下水污染范围的方法。     

接触器高原环境适应性试验研究

为了增强接触器在高原环境条件下的适应性能,提高接触器在高原特殊环境条件下的可靠性水平,特此提出对接触器应通过的环境适应性试验提出了考核评价。     

Population Growth,Available Resources,and Quality of Life:China’s Post-Reform Economic Development

Two opposing intellectual traditions and their contem-porary developments regarding the relations among population, available resources, and quality of life as reflected in economic growth are reviewed. What is at issue is whether population growth is detrimental to or beneficial for economic development. Neither of the extreme views gives a complete picture of the interplay among population, resources, and quality of life. Following previous literature on the topic, this paper establishes a more balanced approach that considers the function linking population and quality of life not constant but variable and regards the limitedness of resources as not absolute but relative to regions and societies. The proposed approach is more flexible in better explaining the relation between population and economic growth. China is examined as a case in point to shed light on the interaction of population growth, economic development, and available resources, and its recent post-economic reform experiences showcase the appropriateness of the synthetic approach.     

太湖塑料添加剂时空分布和生态风险评价

为揭示新冠疫情背景下太湖塑料添加剂的时空分布和风险水平,研究了典型的双酚类、邻苯二甲酸酯类和苯并三唑类等塑料添加剂在太湖表层水体的赋存情况.对全太湖19个监测点位进行4个季度的监测,并评估其潜在的生态风险.结果表明,自2020年秋季至2021年夏季,双酚A（BPA）、邻苯二甲酸二乙酯（DEP）、邻苯二甲酸二（2-甲氧基）乙酯（DMEP）、邻苯二甲基丁基苄基酯（BBP）和苯并三唑（UV-328）在太湖表层水体中均有检出.DEP、 DMEP、 BBP、 BPA和UV-328的检出率分别为100%、 97%、 58%、 98%和7%.对比近年来的塑料添加剂污染水平可以发现,太湖的各类塑料添加剂污染水平并未随疫情背景下塑料制品用量的剧增而加重,反而因人类活动减缓而呈现下降趋势.太湖塑料添加剂检出浓度有明显的季度差异,春、夏季平均值高于秋、冬季,分别是104.7、 100.3、 30.7和29.9ng·L^-1.其在空间分布上也具有一定的差异性,主要表现为高浓度点位聚集在太湖西南沿岸.生态风险评估结果表明,太湖塑料添加剂的赋存对藻类存在低风险,比例达30%,秋、冬季风险性高于...