Rebound effect and its decomposition – an analysis based on energy types in China

Rebound effect derived from energy efficiency improvement has been widely invested. However, most of studies focus on the rebound effect of the energy composite level and neither distinguish nor compare different energy types. We compare the differences in energy saving and energy rebound between primary and secondary energy sources, and further decompose the rebound effect into production rebound part and final demand component. To do so, we add a module for rebound into a comparative state China-CGE model. We design and test two simulation scenarios using the model. In Scenario 1, all production sectors’ energy efficiency of using primary energy increases by 5%. In Scenario 2, all production sectors’ energy efficiency of using secondary energy increases by 5%. The results show that Scenario 2 leads to more GDP growth and more energy saving. Our scenarios show rebound effects range between 9.6% and 27.9%, and in general are higher when energy efficiency of using primary energy sources is improved. Our decomposition analysis shows that improving energy efficiency in production sectors would stimulates energy use of final demand. Indeed, the consumption side has significant contribution to rebound in secondary energy use, especially in crude oil and gas. This study reveals that improving efficiency of using secondary energy is better than improving that of primary energy, both in terms of economic impact and energy rebound. And complementary policies that prevent energy services prices from falling too much can be adopted to reduce rebound. Controlling residential energy use could also be effective in reducing rebound, this has particular implication to economies in which residential energy consumption are far from saturation.     

川南山地林分变化对土壤物理性质和抗蚀性的影响

以川南天然林(TRL)及其转变成的毛竹林(MZL)、檫木林(CML)、柳杉林(LSL)、杉木林(SML)和水杉林(SSL)为对象,研究不同林分土壤物理性质和抗蚀性差异,以主成分分析法(ZCFM)和隶属函数法(LSHM)分别计算的土壤抗蚀性综合值Ⅰ(KSX-Ⅰ)和Ⅱ(KSX-Ⅱ)评价林分变化对土壤抗蚀性的影响,探索简便易行的土壤抗蚀性综合评价方法。结果表明,天然林转变为人工林后土壤物理性质和抗蚀性变差,呈现出有机质和0.25 mm水稳性团聚体含量、水稳性团聚体平均重量直径、团聚度、孔隙度及物理稳定性指数降低,而结构体破坏率、不稳定团粒指数、容重、分散率及侵蚀系数增加。各林分土壤KSX-Ⅰ和KSX-Ⅱ均呈现出TRLCMLSSLLSLMZLSML的规律变化。土壤抗蚀性指标间相关性均达到显著(p0.05)水平;土壤KSX-Ⅰ和KSX-Ⅱ之间呈显著相关关系(p0.05),且两者均与各抗蚀性指标间呈显著相关(p0.05)。说明天然林植被变化后会使土壤抗蚀性降低,影响原有植被水土保持功能,应该加强天然林及其生态功能保护;ZCFM和LSHM均可作为计算土壤抗蚀性综合值的有效方法,但考虑到计算过程的难易度,后者更简便易行。结果为土壤抗蚀性综合评价新方法的建立提供了参考。     

基于铁路客运的中国城市可达性及类型研究

为探究铁路网络时空压缩效应对城市可达性的影响,基于2009年和2014年铁路列车时刻表数据,结合传统数理统计方法及空间分析方法,对中国地级以上城市可达性及其格局演变进行深入分析。结果表明:(1)铁路客运的数量和类型上均有较大变化,特别是始发列车及动车组的大幅增加及高铁的开通运行,中国城市可达性得到一定程度提升,但城市可达性改善地域差异性显著。(2)北上广三大核心城市在城市可达性等级体系中第一层级地位稳固,交通区位条件的差异使得城市可达性等级体系产生一定变化。(3)中国城市可达性绝对及相对差距均呈现出不断扩大趋势,列车停靠数量的极化效应显著、新增加的高速客运更多地向高等级中心城市集聚,铁路基础设施的建设正在重塑中国生产力格局。(4)从城市功能属性及规模属性视角,以始发列车和停靠列车中位数为临界值,将中国城市划分为高规模高功能、高规模低功能、低规模高功能、低规模低功能等4种类型,并依次分析城市分布特征及成因,为铁路客运的合理配置及交通网络优化布局提供参考。     

Fluctuating asymmetry of rodent cranial structures in an industrial pollution gradient

Fluctuating asymmetry (FA) of the mandible shape has been analyzed in bank voles from the zones affected by pollution from three copper smelters in the Urals. It has been shown that there is the necessity for a detailed analysis of the material, since the level of FA may depend on population parameters. Regardless of the pollution level, FA of the mandible region including the lower part of the mandibular body, ramus and processes is higher than in the diastema region. A gradient effect of toxic exposure on FA has been revealed: an increase in its level under increasing technogenic impact is clearly manifested along local pollution gradients.     

Plasticity in metamorphic traits of <Emphasis Type="Italic">Rana kukunoris</Emphasis> tadpoles: The interactive effects of food level and rearing temperature

Larval amphibians are particularly likely to encounter variation in rearing temperature and resource availability due to variation in aquatic breeding habitats. In this study, plasticity in growth rates, larval mass, larval period, and size at metamorphosis were examined in Rana kukunoris Nikolskii, 1918 under different combinations of temperature and food level. Larval period and larval body mass was sensitive to food level, and varied with temperature. Tadpoles metamorphosed at an older age at low temperature than those reared at warm temperature. Food level was a significant affect on larval period at low temperature, but not at warm temperature. Mass was heavier for tadpoles reared at low temperatures than those reared at warm temperatures. The effect of food level depended on temperature, because larvae reared at low temperature that were offered a high food level achieved a larger size than larvae offered a low food level, but this did not occur at warm temperature. Therefore, we suggest that high food availability at low temperature prolonged developmental periods, thus larvae are larger as metamorphs than those reared at warm temperatures.     

Levels and distribution of Dechloranes in sediments of Lake Taihu,China

The occurrence and spatial distribution of dechloranes including mirex, dechlorane plus (DP), dechlorane (Dec) 602, Dec 603, and Dec 604 in surficial sediments of Lake Taihu were investigated in this study. The concentrations of mirex and DP ranged from below detection limit (BDL) to 1.29 ng g^?1 dw and 0.051 to 2.10 ng g^?1 dw, respectively. Dec 602, Dec 603, and Dec 604 on the other hand, were BDL in any of the samples. The contamination levels of DP were higher than that of Mirex at 21 of all 22 sampling sites. Levels of mirex and DP in the lake sediments were correlated when an extremely high mirex value was removed. Both mirex and DP levels were correlated with the amount of organic matters in the sediment samples. Spatial distribution of mirex and DP suggested that these two chemicals in the lake had similar input sources except for one site. Comparison to previously reported flame retardants’ levels in the sediments shows that DP levels were similar with the levels of tetrabromobisphenol A, hexabromocyclododecane but lower than PBDEs and organophosphates levels in Lake Taihu. The higher levels in the north-east part of Lake Taihu adjacent to two major cities: Wuxi and Suzhou, indicated that city effluent might be a major source for DP contamination in the lake.     

隔膜压滤机滤室最优空腔厚度

利用UG软件对隔膜压滤机滤室内流体进行三维建模,导入Gambit中进行网格划分及边界条件的设定,结合Fluent选用RNG k-ε湍流模型,采用多孔介质模型模拟隔膜压滤机滤室内固-液两相流分离,得到不同空腔厚度下滤室内流体的体积分数轮廓图、压强云图,得出滤饼含水率与空腔厚度大小的关系。实验结果表明,模拟和实验结果具有较好的一致性。在压滤机滤室空腔厚度为12 mm时,滤饼含水率为48%,每天污泥处理量为102 t,隔膜压滤机工作效率最高。     

改性糠醛渣吸附脱硫废水中钙离子

石灰石-石膏法烟气脱硫技术中石灰石利用率低导致钙流失严重,为实现脱硫废水中Ca2+的资源化利用,进行糠醛渣改性和Ca2+的吸附特性研究。实验结果表明,利用H3PO4改性后的糠醛渣对脱硫废水中Ca2+具有较高的吸附率;在振荡的前30 min吸附率上升极快,至90 min时基本达到平衡吸附量;对Ca2+浓度对吸附率影响研究结果表明,平衡吸附量与平衡浓度关系符合Langmuir等温吸附方程;在初始Ca2+浓度为300 mg/L的溶液中加入3 g吸附剂,温度30℃条件下振荡90 min,平衡吸附量为8.41 mg/g。     

磷酸铵镁碱促(Mg(OH)_2)热解产物氨氮去除性能

磷酸铵镁热解循环技术可以有效降低磷酸铵镁结晶技术的药剂费用。同时,在磷酸铵镁热解过程中添加Mg(OH)2碱促媒介,能阻止磷酸氢镁向焦磷酸镁的转化,并降低热解产物氨氮去除过程中上清液磷酸盐的残留。在Mg(OH)2∶NH+4摩尔比为1∶1,热解温度为110℃条件下,热解产物沉氨效率接近84%,上清液磷酸盐残留量为0.02 mg/L。     

4种营养元素对水华鱼腥藻和四尾栅藻增殖的影响

以水华鱼腥藻和四尾栅藻分别作为蓝藻,绿藻代表藻种,采用均匀设计实验方法(uniform design experimentation,UDE)设计藻类AGP实验。采用通径分析法(Path Analysis,PA)对氮、磷、铁和锰在不同藻种增殖过程中的影响程度进行分析。结果表明,4种营养元素对水华鱼腥藻增殖影响的决策排序为FeTNTPMn,微量金属元素铁是影响水华鱼腥藻(蓝藻)增殖的主要因素;对四尾栅藻增殖影响的决策排序为TNTPFeMn,常量元素是影响四尾栅藻(绿藻)增殖的主要因素。联合通径分析法和逐步二次方回归分析法(QRA)建立的数学模型,可用于预判藻增殖。