沸石曝气生物滤池去除氨氮性能及生物学特征分析

天然沸石具有较大的孔隙率和比表面积,对氨氮有较强的选择性离子交换能力.运用天然沸石曝气生物滤池处理城市污水厂二级生化出水,结果表明,曝气生物滤池有良好的去除效果.在气水比为3∶1,水力负荷为1 m/h,温度＞20℃情况下,沸石曝气生物滤池对城市污水厂二级生化出水COD去除率为12.7%,NH3-N去除率为96.6%;试验系统沿程微生物活性和微生物量呈现逐渐下降趋势,而单位生物量的生物活性沿程分布则与此相反;曝气生物滤池对水中污染物的去除主要集中在底部进水端部分,当水流达到距进水端上方105 cm时,曝气生物滤池对水中NH3-N的去除率已达86.8%(占氨氮总去除率的90%),COD的去除率为13.3%(占COD总去除率的67%).     

Synthesis of Li-doped bismuth oxide nanoplates,Co nanoparticles modification,and good photocatalytic activity toward organic pollutants

Abstract

Lithium-doped bismuth oxide nanoplates with the thickness of 50–150?nm and tetragonal bismuth oxide, monoclinic lithium bismuthate phases have been synthesized via a simple hydrothermal process using lithium acetate and sodium bismuthate as the raw materials. Cobalt nanoparticles modified lithium-doped bismuth oxide nanoplates hybrids were obtained by an in situ photo-deposition route. The cobalt nanoparticles-modified nanoplates hybrids display significantly enhanced photocatalytic activity toward gentian violet compared with the nanoplates. Gentian violet solution can be totally degraded by the hybrids within 60?min under ultraviolet–visible light irradiation. The superior photocatalytic activity of the cobalt nanoparticles modified nanoplates hybrids originates from the superior charge transfer capacity and the energy band structure of the hybrids. The excellent photocatalytic performance makes the cobalt nanoparticles modified nanoplates hybrids a promising candidate as the photocatalyst for wastewater treatment.     

Distribution normality of pH and H<Superscript>+</Superscript> activity in soil

Soil pH, a log-transformed form of hydrogen ion (H⁺) activity, is often used for various statistics. However whether soil pH meets the requirement of distribution normality for statistical analyses is unknown. We studied the statistical suitability of both soil pH and H⁺ activity by examining their distribution normalities. Results show that the variability of H⁺ activity is higher and its distribution is skewer, which is significantly different from the normal and soil pH, regardless of soil conditions and analytical methods. Here we demonstrate that soil pH is more appropriate than the H⁺ activity for performing statistical analysis in terms of distribution normality.     

氨基酸侧链基团的特异性化学修饰对玉帘凝集素凝血活性和促淋巴细胞有丝分裂活性的影响

石蒜科植物玉帘 (ZephyranthescandidaHerb)的球茎 ,经生理盐水浸取、硫酸铵分级沉淀、DEAE -Sepharose和SephacrylS - 10 0分子筛层析 ,分离纯化出玉帘凝集素 (Z .candidaaggulutination ,ZCA) ,在SDS -PAGE显示单一蛋白带 ,经分子筛层析测得相对分子量 (Mr)约为 4 8× 10 3 .采用不同的化学修饰试剂对玉帘凝集素中的不同氨基酸侧链基团进行修饰 .结果表明 :Arg残基的修饰引起兔红细胞凝集活性下降 73% ,Trp残基的修饰引起兔红细胞凝集活性下降 36 % ;Ser/Thr残基的修饰导致促淋巴细胞有丝分裂活性下降 2 9.3% ,细胞分裂比率下降 7.2 % .图 3表 2参 12     

<Emphasis Type="Italic">Juniperus oxycedrus</Emphasis> ssp.<Emphasis Type="Italic">macrocarpa</Emphasis> in SW Spain: Ecology and conservation problems

Woodlands of the Mediterranean speciesJuniperus oxycedrus ssp.macrocarpa (maritime juniper) are both vulnerable and ecologically important. Their ecology and biological status along the SW coast of Spain are not well known; this, the first major study of these juniper populations is a basis for future research and restoration policies. These communities are subject to harsh conditions, the plant composition being controlled by several factors at different scales. On a large scale, climate and soil texture play an important role in controlling the soil water availability to plants, and in separating xerophytic from mesic communities. On a small scale, coastal physiography, and substrate composition are related to differences in the floristic composition. Coastal plantations modify environmental conditions, such as sand mobility and salt spray deposition, inducing important changes in plant communities. The population of maritime juniper on this coast was estimated in ca. 25 000 individuals, of which 93.6% are concentrated in three locations. Large proportions of young individuals were found in extensive and protected populations. Howerver, adult individuals dominated the smaller populations located under pine plantations. This limitation of recruitment may be imposed by several factors. A male biased ratio was detected on the southern coast of Cádiz, which I hypothesize is due to the lower cost of pollen production in a stressful habitat. Preservation of suitable habitats, the recovery of abandoned pine plantations, and the connection between juniper populations, seem to be important requisites for the conservation of maritime juniper in the southwestern coast of Spain.     

MnO2.CuO／Al2O3催化剂上CO的常温催化氧化研究

本文研究了CO常温氧化的催化剂——MnO_2·CuO/Al_2O_3。考察了活性组分MnO_2,CuO的相对百分含量,浸渍溶液的酸度、焙烧温度、反应温度等因素对催化剂活性的影响。发现催化剂的活性与其差热分析的脱水峰及分解反应(MnO_2→Mn_2O_3)的峰温存在一定的对应关系。     

微生物絮凝剂SC06的化学组成和特性

纤维堆囊菌（Sorangium cellulosum NUST 06）产生一种胞外多糖絮凝剂。用乙醇沉淀和Sepharose 4B凝胶层析纯化得到纯品SC06，通过气相色谱和红外光谱分析，SC06由葡萄糖、甘露糖和葡萄糖醛酸组成，其比较约为5∶3∶1，SC06的絮凝活性依赖于阳离子的存在，在pH2-9范围内絮凝活性稳定。     

光(温)敏核不育水稻生态及生理生化研究概述

本文介绍了光、温敏核不育水稻在生态及生理生化方面取得的主要成就.着重概述了光、温敏核不育水稻雄性育性转换的光温生态条件,育性转换过程中蛋白质、氨基酸、酶活性、ATP及内源植物激素持续变化.另外,对光、温敏不育水稻研究存在的问题进行了分析.     

阿特拉津对不同肥力土壤磷酸酶的影响

通过室内恒温培养法，研究除草剂阿特拉津对4种长期定位施肥处理下的土壤的磷酸酶活性的影响。试验结果表明，在阿特拉津质量分数不同和处理时间长短不同的情况下，阿特拉津对土壤磷酸酶的活性既有激活作用又有抑制作用。在试验过程中，4种不同肥力的土壤其磷酸酶活性随着处理时间的延续而呈现出“降低→升高→降低→升高”的消长趋势。不同阿特拉津质量分数对磷酸酶的影响没有规律，同一质量分数处理既有激活作用，也有抑制作用。在4种不同肥力的土壤中，磷酸酶活性最高的是以氮、磷、钾无机肥配合有机肥施用的土壤。