结构变动、技术进步以及价格对能源效率的影响

本文旨在分析中国工业化进程中影响能源消耗及其效率的主要因素。通过理论研究,我们认为经济结构、技术进步以及能源市场化改革是中国工业化进程中的主要影响因素。从这些影响因素的作用机理来看,经济结构与工业化阶段密切相关,对能源效率的影响是一个长期的过程;而在经济结构相对稳定的短期内,技术进步是提升能源效率的重要因素;在市场经济条件下,能源价格是提高能源效率的长期而稳定的激励机制。在此基础上,我们综合利用1990-2006年省际、四大区域、13个主要工业省区面板数据,以及工业行业数据,实证估计这些因素对能源效率的影响程度。几个估计结果综合显示,这三大因素对中国工业化进程中的能源效率具有重要的影响作用。这意味着当前节能减排的政策重点必须立足于长期,谨慎采用单纯的节能降耗这种行政命令式的短期策略,重点采用基于激励机制的治理策略,弱化长期以来形成的高耗能技术结构,引导节能环保型技术的创新与扩散。     

The distribution of radon in tunnels with different geological characteristics in China

In China, as the economy is developing and the population is expanding, some underground buildings have been used as supermarkets, restaurants and entertainment places. Tunnels in mountains are one type of underground building, and the radon (²²²Rn) level in tunnels is an important issue. Radon levels in different type tunnels appear to differ, and relatively higher levels of ²²²Rn are associated with particular types of bedrock. The ²²²Rn levels in tunnels in five different geological characteristics were analyzed. Those built in granite had the highest ²²²Rn levels with a geometric mean (GM) of 280 Bq m⁻³, while those built in limestone (GM: 100 Bq m⁻³) and andesitic porphyry (GM: 96 Bq m⁻³) were lower. The sequence of ²²²Rn concentrations was: granite > tuff > quartz sandstone > limestone > andesitic porphyry, and the ²²²Rn in granite was statistically significantly higher than in limestone and andesitic porphyry. Tunnels built in granite, tuff, quartz sandstone, limestone tended to have higher ²²²Rn concentrations in summer than in winter, while the reverse tendency was true in andesitic porphyry tunnels. Only the difference in limestone was statistically significant.     

Discussion on the Regional Division of the Development Stage of China's Wind Power

This paper constructs the index system of the regional division of the development stage of China's wind power resourc-es, including the index of energy, the index of wind energy endow-ments and other indices. Based on principal component analysis and layered clustering analysis of these indices, and combined with the conceptual function of the development and utilization stage of the wind power, this paper divides the development and utilization stage of the wind power into four stages taking province as the basic yardstick: optimization growth stage, the rapid growth stage,the slow growth stage and the initial growth stage. In addition, this paper briefly discusses the basic strategy that should be adopted in each development stage of wind power resources.     

Occurrence, bioaccumulation and potential sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of South China

To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (±standard deviations) at 5.7 ± 3.6 ng/L in pond water, 15 ± 11 ng/g dry wt. in pond sediment, 12 ± 3.8 ng/g dry wt. in bank soil, 21 ± 20 ng/g lipid wt. in fish, and 93 ± 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish.     

近55年来华东地区旱涝时空变化特征

基于华东地区89个气象站点近55年逐月降水资料,运用趋势分析法、IDW空间插值法、标准化降水指数(SPI)等方法,分析了1960~2014年期间我国华东地区旱涝灾害时空变化特征,并探讨了淮河南北旱涝的时空差异。结果表明:(1)近55年华东地区降水量整体呈波动上升趋势,其中淮河以北地区降水量呈波动下降趋势,而淮河以南呈上升趋势。(2)从年尺度旱涝变化看,华东地区雨涝频率大于干旱频率,但干旱强度大于雨涝强度,且淮河以南地区的干旱强度大于淮河以北,而雨涝强度小于淮河以北。(3)华东地区南北旱涝站次比呈反向发展趋势,即淮河以北旱灾影响范围不断扩大,雨涝影响范围不断减小,淮河以南与之相反。(4)华东地区严重旱涝频率在空间分布上呈南北反向格局,即淮河以北旱灾频率高,涝灾频率低;淮河以南涝灾频率高,旱灾频率低。     

西南地区某已封场非规范垃圾填埋场垃圾稳定化进程分析

以重庆某非规范填埋场为例,针对西南地区已封场非规范垃圾填埋场的稳定化进程进行了分析。按照场地布局选取4个采样点,在垃圾体上进行钻孔取样,分析不同深度的垃圾样pH值、有机质、含水率、生物可降解度以及垃圾样浸出液和填埋气组成以及各个指标随着填埋深度的变化规律,确定不同深度垃圾体的稳定化程度。结果表明,场内垃圾已呈现矿化垃圾特征;有机质、BDM、浸出液COD以及填埋气CH4含量等4个指标与填埋深度均较好地符合一级降解反应,可以预测垃圾体稳定化临界填埋深度。根据有机质、BDM、浸出液COD以及填埋气CH4含量等4个指标与填埋深度一级降解反应函数预测临界稳定化深度为15 m,与实测值判定的稳定化填埋深度相一致性。在对非规范垃圾填埋场场地利用过程中,需要先对未稳定的上层垃圾进行清理,并在已稳定的底层垃圾体上充填其他稳定介质后利用该地块。     

Levels and profiles of long-chain perfluorinated carboxylic acids in human breast milk and infant formulas in East Asia

In this study, 90 human breast milk samples collected from Japan, Korea, and China were analyzed for perfluorooctanoic acid (PFOA) (C8), perfluorononanoic acid (PFNA) (C9), perfluorodecanoic acid (PFDA) (C10), perfluoroundecanoic acid (PFUnDA) (C11), perfluorododecanoic acid (PFDoDA) (C12), and perfluorotridecanoic acid (PFTrDA) (C13). In addition, infant formulas (n = 9) obtained from retail stores in China and Japan were analyzed. PFOA was the predominant compound and was detected in more than 60% of samples in all three countries. The PFOA, PFNA, PFDA, and PFUnDA levels in Japan were significantly higher than those in Korea and China (p < 0.05). The PFTrDA level was highest in Korea (p < 0.05). The median PFOA concentrations were 89 pg mL⁻¹ (48% of total perfluorinated carboxylic acids (PFCAs) (C8-C13)) in Japan, 62 pg mL⁻¹ (54%) in Korea, and 51 pg mL⁻¹ (61%) in China. The remaining ∑PFCAs (C9-C13) were 95 pg mL⁻¹ in Japan, 52 pg mL⁻¹ in Korea, and 33 pg mL⁻¹ in China. Among the long-chain PFCAs, odd-numbered PFCAs were more frequently detected than even-numbered PFCAs, except for PFDA in Japan. There were no evident correlations between the mother’s demographic factors and the PFCA concentrations. PFOA, PFNA, and PFDA were frequently detected in both Japan and China, but there were no significant differences between the two countries. The total PFCA concentrations in the infant formulas were lower than those in the breast milk samples in Japan (p < 0.05), but not in China (p > 0.05). In conclusion, various PFCAs were detected in human breast milk samples from East Asian countries.     

基于标准化降水蒸散指数的华南干旱趋势研究

最近几年华南地区干旱频发,为探讨该地区的干旱趋势,用标准化降水蒸散指数(SPEI)和1961-2010年华南地区具有代表性的50个站点的月降水及月平均气温资料,分析了该地区近50年来的干旱趋势、干旱空间分布、极端干旱事件发生频次和干旱持续时间。结果表明,华南地区普遍存在干旱事实,最近10年是干旱最严重的10年,Mann-Kendall检验表明该地区平均SPEI指数从1998年开始突变;干旱化最严重的区域是海南岛、广西南部和西部地区,广东的干旱化趋势最轻。20世纪70年代干旱和极端干旱事件较少,其后明显增多,干旱持续时间也有所延长。由于该地区降水呈现弱增加趋势而温度升高显著,因此推测温度升高导致蒸散增加可能是华南地区干旱化的主要原因。另外,降水频次的减少和集中也是导致近来极端干旱事件增多的原因之一。SPEI指数较好地体现了气候变暖导致的干旱化趋势。     

2008-2009年中国北方干旱遥感动态监测

干旱是威胁我国及世界农业发展的自然灾害之一,利用遥感技术进行干旱监测与评估已成为一种重要而有效的手段。2008年10月至2009年2月,我国北方地区出现了大面积的持续干旱,给冬小麦的生长造成了严重的影响。基于2000年至2009年Terra卫星MODIS传感器8天合成的地表反射率数据,结合地面实测土壤水分和实地调研数据,利用距平植被指数(AVI)和距平水分指数(AWI)对我国北方冬小麦主产区的干旱程度进行了分级,对干旱的发生、发展和时空变化情况进行了连续监测,得到了该时期的旱情分布结果:2008年10月份以后旱情逐渐加重,2009年1月下旬各地旱情达到了最严重的程度。研究表明,AWI对干旱的反应比AVI敏感而且准确。     

一次中尺度对流系统的发生发展特征分析

通过分析2008年6月23日形成于冷涡成熟阶段的中尺度对流系统(MCS)的发生发展特征,得到:(1)MCS发生发展过程中,高空强垂直风切变维持,低层垂直风切变迅速增大。(2)湿Q矢量的低层辐合、高层辐散,加强了上升运动和次级环流,前者的增大对MCS的发展起了更大的作用。(3)雷达图上弱回波区、回波悬垂结构、三体散射现象、大的垂直累积液态水及低层速度图上的气旋式辐合的出现是冰雹发生前的有利信号。(4)湿斜压性及风垂直切变增大可能会促发MCS发生。地面风场辐合和水汽辐合加强了MCS的发展。对流层中高层干冷空气的侵入,使不稳定能量释放,导致了强对流天气的发生。