水稻和玉米的热氧化分解特性及几种动力学方法结果的比较

利用热重分析仪在空气气氛、不同的升温速率下对带壳稻谷粉和玉米粒粉进行了热重测试,依据热重实验数据,采用多种热解动力学分析方法计算了水稻和玉米的活化能数值并进行比较,结果表明水稻和玉米的热氧化反应活化能随着转化率出现先增加后降低的趋势,并在转化率为70%左右达到了极大值。     

走向工作面贯通上山与支架快速回撤技术

针对走向工作面停采线与上山之间的护巷煤柱造成煤炭损失,支架回撤工艺复杂、巷道掘进量大等问题,提出走向工作面贯通上山与支架快速回撤技术。工作面贯通采区上山,利用上山回撤支架。在贯通前,利用压力拱模型分析剩余煤柱应力变化规律,并结合极限平衡区公式,确定让压煤柱为8 m;对贯通前基本顶合理断裂位置、让压调节机制、末采阶段采高进行了分析确定,并采取上山巷内补强支护及挂绳铺网措施。贯通上山后,首先利用支架对上山留巷,完成留巷后,利用上山回撤支架,先将上部端头3架逆时针旋转90°作为掩护架,在对剩余支架逐架回撤时,3个掩护架呈现台阶型。提出的技术取消了护巷煤柱及回撤通道,提高了煤炭采出率,减少了巷道掘进量,简化了回撤工艺。     

Does regional energy consumption disparities assist to control environmental degradation in OBOR: an entropy approach

China launched the One Belt & One Road (OBOR) initiative to minimize the energy resource shortage. The China’s nearby countries are rich in energy resources especially Middle East and North Africa (MENA) and Asian countries which make them ideal locations to cooperate with China in terms of energy resources, as 42.8% of world energy consumption belongs to OBOR countries. The present study elaborates the spatial distribution pattern of energy consumption disparities and its impact on environment. To do this, an entropy approach is utilized to compute the energy consumption inequalities in OBOR and its regions. The spatial and Pareto analysis show that MENA, East, and Southeast Asian economies have the highest degree of energy consumption inequalities, while European and Central Asian economies show the lowest energy consumption inequalities in OBOR region. The long-run estimates indicate that energy consumption inequalities enhance the CO₂ emission in OBOR and its region except South and Southeast Asia. Financial development also has a significantly positive impact on CO₂ emission in all models for OBOR and its regions except East Asia. Based on findings, the spatial distribution analysis is applicable to maintain balance in regional energy consumption inequality within OBOR and its regions.

     

3种喹诺酮类抗生素在骆马湖饮用水源地沉积物上的吸附特征

为探究喹诺酮类抗生素(QNs)在饮用水源地的吸附特征,2019年6月于江苏骆马湖饮用水源地采集沉积物样品,用5种动力学方程拟合沉积物对诺氟沙星(NOR)、环丙沙星(CIP)和氧氟沙星(OFL)的吸附动力学过程,并用Langmuir和Freundlich模型拟合以上3种QNs的吸附热力学过程,分析了pH、水土比和不同Na~+、Ca~(2+)、Mg~(2+)、Al~(3+)浓度对吸附过程的影响。结果表明:骆马湖沉积物对3种QNs的吸附在8h达到平衡,准二级动力学方程和Langmuir模型能更好地描述3种QNs的吸附动力学和热力学过程。酸性条件下,3种QNs的吸附效果更好,且在pH=5时平衡吸附量最大。平衡吸附量随着水土比的上升而下降。Na~+对吸附的抑制作用不明显,Ca~(2+)和Mg~(2+)的抑制作用较强,而Al~(3+)对吸附表现为促进作用。应在枯水期和南水北调时期加强对骆马湖饮用水源地(尤其是东北部)QNs污染的关注。     

Effects of environmental regulation on firm entry and exit and China’s industrial productivity: a new perspective on the Porter Hypothesis

Environmental Economics and Policy Studies - This paper dissects the effects of environmental regulation on the productivity of pollution-intensive industries and by doing so offers a new...     

地下铀矿山留矿法采场受限空间内氡迁移的数值模拟

为研究铀矿山留矿法采场氡迁移规律,依据留矿法采场的构造和物理几何尺寸,建立了受限空间内颗粒堆积型射气介质气体流动的数学模型和氡迁移方程,以10 m和20 m高爆破矿堆为对象,采用计算流体力学(CFD)方法,研究了不同通风条件下采场中氡的迁移规律。结果表明:1)采场下行通风方式降低矿堆上部作业空间氡浓度的效果优于上行通风方式,但对采场运输巷道氡浓度的效果相反;采场排风氡浓度与采场通风风量成反比,氡析出份额与通风风量成正比;2)在相同通风风量下,10 m高爆破矿堆与20 m高爆破矿堆氡析出份额之差随通风风流量增长而逐渐缩小;3)均压通风对渗透率高(k=1×10-8m2)的采场排风氡浓度、矿堆氡析出份额有明显影响。     

煤与瓦斯共采在错层位巷道布置中的机理研究及应用构想

为了完善现有煤与瓦斯共采技术,创新煤与瓦斯共采方法,对错层位巷道布置下的煤与瓦斯共采系统展开研究,利用相似模拟试验,分析错层位巷道布置覆岩运动情况,预测其开采围岩裂隙发育和瓦斯运移形式,提出了创新煤与瓦斯共采技术构想。研究结果表明:采空区覆岩三带高度随接续工作面的增加而增大,相邻采空区垮落矸石压实区呈现“O-L-O”形变化,多个相邻采空区覆岩出现大“O”形圈裂隙带;相邻采空区内瓦斯可实现相互运移,大“O”形圈裂隙带内赋存大量瓦斯气体;研究提出了地面钻井抽采瓦斯、走向高位瓦斯抽采巷和外错尾巷穿层钻孔3种煤与瓦斯共采技术,比传统巷道布置情况下的煤与瓦斯共采技术在安全、经济等方面更具优势。     

Effects of Topographical Heterogeneity and Dispersal Limitation on Species Turnover in a Temperate Mountane Ecosystem: a Case Study in the Henan Province,China

Species turnover patterns can be inconsistent due to differences in the dispersal ability of different growth forms. Here, species of trees, shrubs, herbs, and bryophytes in the Xiaoqinling National Nature Reserve in China were analyzed to determine patterns of species turnover along an elevation and spatial gradient. Variance partitioning was used to assess the relative contribution of topographic heterogeneity and dispersal limitation to species turnover. Our results suggest that the effect of dispersal limitation is more important than topographic heterogeneity on species turnover in temperate mountane ecosystems in the study area. Dispersal limitation has a greater effect on trees species turnover than on shrubs, herbs or bryophytes species turnover.     

珠江口表层水中多环芳烃的分布特征及健康风险评估

分别于2015年2、5、8、11月在珠江八大入海口采集表层水体样品,应用固相萃取富集法对该区域表层水体中16种USEPA优控多环芳烃(PAHs)的时空分布特征进行分析,并利用终生致癌风险增量模型(ILCR)对该区域的饮水健康风险进行评价。结果表明:珠江口4个季度所采集的水样中,∑15PAHs的浓度范围为18.0~50.3 ng/L,含量处于中等水平。其中7种强致癌性∑7PAHs的浓度范围为1.53~3.73 ng/L,占∑15PAHs的5.89%~11.1%,∑15PAHs和∑7PAHs在枯水期(2、11月)样品中明显高于丰水期(5、8月)。就组成特征而言,各采样点PAHs以3、4环为主。珠江口表层水中非致癌类PAHs的危害商数值为0.99×10~(-5)~2.73×10~(-5),远低于USEPA规定的阈值(1);致癌类PAHs产生的健康风险为6.50×10~(-8)~2.37×10~(-7),其中Ba P导致的饮水途径健康风险最高,所有点位致癌类PAHs的健康风险均低于USEPA推荐的对致癌物质最大可接受风险水平(10~(-6)),表明珠江口表层水中PAHs尚不具备严重的致癌风险,但是仍然存在潜在的健康风险,需要重点控制和管理。     

以活性染料为主要成分的印染废水的混凝脱色试验

用硫酸亚铁、碱式氯化铝(PAC)和聚丙烯酰胺(PAM)对以活性染料为主要成分的印染废水进行混凝脱色试验,阐述了混凝脱色机理,对脱色影响因素和控制条件等进行了试验研究.