衢州:松毛虫害缘何归零

2007年7月4日,风景区衢州烂柯山上来了一批"特殊"的客人——衢州市林业局森林病虫害防治检疫站站长华正媛一行。他们不看美景,只关注树林里人工制作的鸟巢:外形和信箱有些相似,用木板铁丝做成,质朴有趣,和周围的环境十分协调。华正媛说:"这是为山喜鹊等‘森林卫士’准备的‘现房’,半个月前刚     

Biosorption of uranium (VI) by immobilized Aspergillus fumigatus beads

Biosorption of uranium (VI) ions by immobilized Aspergillus fumigatus beads was investigated in a batch system. The influences of solution pH, biosorbent dose, U (VI) concentration, and contact time on U (VI) biosorption were studied. The results indicated that the adsorption capacity was strongly affected by the solution pH, the biosorbent dose and initial U (VI) concentration. Optimum biosorption was observed at pH 5.0, biosrobent dose (w/v) 2.5%, initial U (VI) concentration 60 mg L⁻¹. Biosorption equilibrium was established in 120 min. The adsorption process conformed to the Freunlich and Temkin isothermal adsorption models. The dynamic adsorption model conformed to pseudo-second order model.     

Growth and potential reproduction of <Emphasis Type="Italic">Poa crymophila</Emphasis> in response to season precipitation shortage in the Eastern Tibetan Plateau,China

The growing season in 2006 existed a quite less precipitation than previous years in the eastern of Tibetan Plateau, China. In order to explore the response strategies of the grass to drought year, the variations of growth and potential reproduction of Poa crymophila between rich (2005) and poor rainfall year (2006) were studied. Reproductive shoot biomass, above- and below-ground biomass pronounced decreased in the poor rainfall year, but the ratio of above-/below-ground biomass and vegetative shoot biomass increased. Carbon content in inflorescence increased significantly in 2006, but decreased significantly in root. Nitrogen contents and the C/N ratios in plant components were not significantly different. Sexual reproduction in 2005 and 2006 was not different. Season precipitation shortage could result in the higher mortality of vernal budding shoots or tillers. The results suggested that P. crymophila response to poor rainfall year (drought) by a smaller plant body, allocating more proportional biomass to above-ground, altering more carbon to inflorescence, and altering its reproductive way to sexual.     

生态哲学的功能与生态素质的提升

生态素质作为以生态世界观和生态方法论为核心、以生态价值观和生态伦理观为观照、以生态思维方式和生态行为规范为主要内容的人的内化物,它必然体现当今乃至未来人类素质的主体内容和发展的主导趋势。在新的历史条件下,生态哲学的研究应全面强化在有效提升人的生态素质方面的独特功能。     

Changes in speciation and leaching behaviors of heavy metals in dredged sediment solidified/stabilized with various materials

Solidification/stabilization (S/S) of sediments is frequently used to treat contaminants in dredged sediments. In this study, sediment collected from the Pearl River Delta (China) was solidified/stabilized with three different kinds of functional materials: cement, lime and bentonite. Lime primarily acted via induced increases in pH, while cements stabilization occurred through their silicate-based systems and the main function of bentonite was adsorption. The speciation and leaching behaviors of specific heavy metals before and after S/S were analyzed and the results showed that the residual speciation of Cd, Cr, Ni, Pb and Zn increased in all treatments except for Cu, as the exchangeable speciation, carbonate-bound speciation and Fe-Mn-oxide-bound speciation of Cu (all of which could be stabilized) were less than 2 % of the total amount. Pb leaching only decreased when pH increased, while the mobility of Cr and Ni only decreased in response to the silicate-based systems. The leached portion of the Fe-Mn-oxide-bound speciation followed the order Zn?>?Cu?>?Ni/Cd?>?Pb?>?Cr. The leached portion of organic-matter-bound species was less than 4 % for Cd, Cr, Ni and Pb, but 35.1 % and 20.6 % for Cu and Zn, respectively.     

四川城市对称性空间结构研究

城市空间分布规律的研究一直是城市规划者和地理学家研究的热点。早期关于城市空间分布的理论有克里斯泰勒的中心地理论、廖什网络结构理论等,现在研究较热的是基于人类空间行为自组织演化的分形理论。我国著名地学家叶大年先生于2001年提出我国城市分布对称的思想,并将其系统整理为关于城市分布对称的学术思想。成渝经济区的崛起,为四川省城市空间结构的优化带来了重要的契机。依据叶大年先生的城市分布对称理论,认为四川主要城市在地质构造等自然地理要素的影响下对称分布明显,且盆西平原城市在天然水系特征和陆路交通干线共同影响下呈格子状分布。针对当前四川省主要城市空间结构发育的不成熟,对成渝经济区影响下的四川城市空间分布形态重新进行空间构建,首次提出关于四川城市空间结构的“钻石模型”。分析表明,此模型能够较好地解释当前川内城市的空间分布及演化趋势;同时也在一定程度上说明城市分布对称的思想具有一定的理论价值和实践价值,值得学者引起重视     

Toxic effect of tetracycline exposure on growth,antioxidative and genetic indices of wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Introduction  

More attention has been paid to tetracycline contamination in view of its rapid increasing concentration in the environment. Therefore, it is important to set up rapid, simple, and accurate methods for monitoring tetracycline ecotoxicity.     

北京城市水系水环境模拟及情景分析

城市水系是流域水环境管理中最为脆弱的控制点.针对城市水系水动力条件差、有机污染和富营养化严重的问题,应用QUAL2K模型模拟、预测城市水系水环境的时空变化,并在此基础上探讨北环水系水环境管理和污染防治的合理有效方案.结果显示,经过多次调整后的模型模拟的匹配度达到了0.9135,水温、溶解氧、COD、TN、TP和Chl-...     

稠油降解菌的筛选、鉴定与菌群构建

分别以烷烃、芳烃、胶质沥青质为唯一碳源,从稠油污染过的土壤里分离、筛选可培养的降解菌,将16株组合构建SL-16稠油降解菌群,通过室内摇瓶实验测得该菌群在最佳条件下对陈庄油田稠油降解率可达68%,其适宜的生长及降解温度为35～45℃,pH值为7.0～9.0,含盐量为4 000～14 000 mg/L,接种量为2%,稠油...     

缩聚-Fenton-A/O生物流化床组合工艺处理酚醛废水的工程案例分析

以广州某公司生产酚醛树脂时产生的酚醛废水为研究对象,针对其高浓度、生物毒性强、可生化性差及难降解等特点,设计缩聚-Fenton-A/O生物流化床联合工艺进行处理。此工艺的工程实践中,在总HRT低于75 h的操作条件下,当进水COD、苯酚及甲醛浓度分别为1.0×105～1.2×105 mg/L、2.2×104～2.5×1...