河南省洪涝灾害时间序列的分形特征与R/S分析

基于河南省1000~1999年的洪涝灾害统计资料,运用分形理论对河南省洪涝灾害的时间序列特征进行分析,发现河南省洪涝灾害发生时间序列的分步呈现出明显的分形特征,其分形维数为0.517,同严格意义上的数学分形Cantor集合相比分维数较小,说明河南省洪涝灾害发生发展的自组织程度还有进一步发展的趋势,其危害程度将可能进一步提高;在河南省洪涝灾害发生时间序列的分形特征的基础上,通过R/S分析,得出该省洪涝灾害发生时间序列的H指数为0.580,说明河南省洪涝灾害具有长期相关性,且未来的洪涝灾害发生的次数具有不断增加的趋势。     

Estimating the Relative Efficiency of Brazilian Publicly and Privately Owned Water Utilities: A Stochastic Cost Frontier Approach1

Abstract: This paper assesses cost efficiencies of Brazilian public and private companies of water supply. To measure the efficiency, we used a stochastic frontier model derived from the translog family – a specification similar to a Cobb‐Douglas including a quadratic term in log output. The model parameters are estimated by maximum likelihood using Brazilian data for the year 2002. Statistical inference leads to the conclusion that there is no evidence that private firms and public firms are significantly different in terms of efficiency measurements.     

Teil III: Praktische Erfahrungen mit dem Umweltmanagement in der Landwirtschaft

Zusammenfassung  Im Rahmen praktischer Untersuchungen der Autoren zu Umweltmanagementsystemen in der Landwirtschaft, und hier insbesondere der Umweltprüfung, zeigen sich die Besonderheiten der Agrarwirtschaft im Implementierungsproze?. Einige Bereiche k?nnen relativ einfach umgesetzt werden, andere Aspekte bedürfen einer differenzierteren Methodik als bei anderen Wirtschaftsbereichen. W?hrend sich das Managementaudit durch die übersichtliche Organisationsstruktur landwirtschaftlicher Betriebe meist als unkritisch erweist, werden beim Wirkungsund Rechtsaudit einige bereichsspezifische Probleme erkannt. Das Wirkungsaudit zeigt dem Anwender nach der Einführung einer neuen, speziell auf die Landwirtschaft angepa?ten Methodik der Stoffstrombilanzierung praxisorientierte Handlungspotentiale. Die Ergebnisse k?nnen je nach Bedarf auf Betriebs-, Betriebszweigoder Kostentr?gerebene ausgewiesen relevant, da sie einhohes ?kologischen Gef?hrdungspotential besitzen und bei den praktischen Erhebungen h?ufig Gegenstand von Beanstandungen waren. Diese betreffen vor allem die Lagerung von umweltrelevanten Stoffen (Pflanzenschutzmittel, Diesel, Jauche, Gülle, Festmist oder Sickers?fte) sowie die etwaigen Notwendigkeit und Beschaffenheit eines Waschplatzes. Die Konfliktbereiche werden beschrieben und darauf aufbauend Optionen zur Verbesserung aufgezeigt. Online-Publikationsdatum: 20.12.1999     

β-环糊精接枝壳聚糖对酸性红R的吸附研究

为改善壳聚糖的吸附性能,用苯甲醛保护壳聚糖氨基,通过与环氧氯丙烷和β-环糊精的反应合成了新的吸附剂β-环糊精接枝壳聚糖,研究了其对偶氮染料酸性红R的吸附行为,考察了酸性红R的初始浓度、pH对吸附效果的影响。结果发现当酸性红R的浓度≤100mg/g时,合成物的吸附量随酸性红R浓度的增大而增加,当浓度进一步增大时,吸附量趋于平衡。合成物对酸性红R的吸附效果在pH为2～4之间最好。相比于Freundlich吸附等温式(R2=0.8476),β-环糊精接枝壳聚糖对酸性红R的吸附规律明显更符合Langmuir吸附等温式(R2=0.9977)。吸附动力学采用了准一级速率方程(R2=0.8609)和准二级速率方程来描述,结果表明吸附动力学符合准二级速率方程(R2=0.9945)。β-环糊精接枝后的壳聚糖对酸性红R的平衡吸附容量可以提高20.2mg/g。     

循环经济中隐藏的“学问”

阐速了循环经济内涵的经济学解释及循环经济实践中的经济学原理,对现阶段我国循环经济的理论和实践进行了总结。     

HAP/UV催化降解活性艳蓝K-3R的研究

用化学沉淀法合成羟基磷灰石(HAP),并用XRD、SEM、FT-IR对其进行分析。以活性艳蓝K-3R为降解底物,研究HAP对其光催化降解性能。探讨了HAP煅烧温度、通气量、投加量、初始浓度等因素对光催化降解活性艳蓝K-3R效果的影响。研究表明化学沉淀法合成的HAP粒度均匀,HAP对活性艳蓝的吸附作用较强,30min之内即能达到吸附平衡,其对初始浓度为100mg/L的活性艳蓝的吸附率可达17.5%。适当的煅烧有利于提高HAP的催化活性,以200℃煅烧2h最佳。在投加量为4g/L,鼓气量为300L/h和pH=6的试验条件下,HAP(200℃)对初始浓度为100mg/L的活性艳蓝K-3R 3h的降解率达68%。降解反应动力学研究表明,HAP/UV光催化降解活性艳蓝K-3R的过程符合Langmuir-Hinshel-wood一级动力学方程,降解速率常数k随着活性艳蓝K-3R浓度的增大而减小。     

地下土壤渗滤系统脱氮效果的研究

在地下土壤渗滤系统运行的过程中,污水中的总氮主要是通过硝化作用及反硝化作用去除的。但是由于反应条件的限制,该系统出水中总氮的浓度总是不能使人满意。分析目前常用的三种提高总氮去除效率的地下土壤渗滤系统得出:间歇进水,并且在一定土壤层深度为微生物的活动提供有机物可以显著降低出水中总氮的浓度。     

Experimental study on the influence of flame retardants on the flammability of R1234yf

As an alternative refrigerant, R1234yf shows great environmental friendliness. However, the flammability has a negative impact on its use and promotion. To lower the combustible risk, it's a proper way to mix with nonflammable refrigerants in applications, but the research on the flammability of these blends is still limited. Therefore, the influence of three typical nonflammable refrigerants CO₂, R1336mzz(E) and R1233zd(E) as flame retardants on the flammability of R1234yf was experimentally studied in this paper. With the measurements of flammable limits of R1234yf/CO₂, R1234yf/R1336mzz(E) and R1234yf/R1233zd(E) at different concentrations, the parameters of regression equations for their flammable limits were obtained. The critical suppression concentrations of retardant were determined as 0.575, 0.35 and 0.6, respectively. The results showed that their suppression abilities could be ranked as R1336mzz(E)>CO₂>R1233zd(E). Then the inhibition mechanisms were analyzed, and the differences in flame colors at flammable limits were compared. With the establishment of estimation model for calculating critical suppression concentrations of ternary blends, the critical suppression lines of CO₂/R1234yf/R1336mzz(E) and CO₂/R1234yf/R1233zd(E) were obtained, by which the nonflammable zones of them were preliminarily determined. The results will provide practical guidance for the applications utilizing R1234yf and its blends in safety.     

中国荸荠属植物果皮微形态特征及其分类学上的意义

报道了国产荸荠属２６ 种、３ 变种植物果皮在扫描电镜下的纹饰特征．结果表明,根据果皮细胞形状和外壁纹饰的差异,可分：（１） 光滑型纹饰：果实表面光滑,无细胞结构;（２） 网状纹饰：在（２） 类型中根据植物果皮垂周壁的结构和细胞形态又可分为两个亚型,即网状纹饰亚型和波形网状纹饰亚型．本属植物果皮微形态特征总体而言较为相近,表明是一个自然类群．果皮纹饰类型及微形态特征在组间或系间相互交叉和渗透,与传统分类中组、系的划分不相对应．此外,本属果皮微形态特征在种下等级的差异较明显,但在种内个体间比较稳定,变异很小．上述研究结果可为国产荸荠属种间区别提供依据．     

Variability and predictability of sea-level extremes in the Hawaiian and U.S.-Trust Islands—a knowledge base for coastal hazards management

The objective of this study is to provide an improved climatology of sea level extremes on seasonal and long-term time scales for Hawaii and the U.S-Trust islands. Observations revealed that the Hawaiian and U.S.-Trust islands, by and large, display a strong annual cycle. For estimating the statistics of return period, the three-parameter generalized extreme value (GEV) distribution is fitted using the method of L-moments. In the context of extremes (20- to 100-year return periods), the deviations in most of the Hawaiian Islands (except at Nawiliwili and Hilo) displayed a moderate sea-level rise (i.e., close to 200 mm), but the deviations in the U.S.-Trust islands displayed a considerably higher rise (i.e., more than 300 mm) in some seasons due to typhoon-related storm surges. This rise may cause damage to roads, harbors, and unstable sandy beaches. Correlations between the El Niño-Southern Oscillation (ENSO) climate cycle and the variability of seasonal sea level have been investigated. Results show that correlation for the station located west of the International Date Line (DL) is strong, but it is moderate or even weaker for stations east of the DL. The skill of SST-based Canonical Correlation Analyses (CCA) forecasts was found to be weak to moderate (0.4–0.6 for Honolulu, Kahului, Hilo, and Wake, and 0.3 or below for Kahului, Mokuoloe, and Johnston). Finally, these findings are synthesized for evaluating the potential implications of sea level variability in these islands.