The study of fine and coarse particles, and metallic elements for the daytime and night-time in a suburban area of central Taiwan, Taichung

Daily average concentrations of fine and coarse particulates, and TSP samples have been measured simultaneously at daytime and night-time periods by using Universal and PS-1 sampler in a suburban area of central Taiwan from June to August 1998. The samples were analyzed by atomic absorption spectrometry to determine the fine and coarse particulate concentrations of metallic elements (Ca, Fe, Mn, Pb, Cu, Zn and Cr). The concentration of PM2.5 and TSP showed a decreased trend for the daytime period. The fine particle concentrations were about two times as that of coarse particulate concentrations. The averaged fine particulate concentrations at daytime are higher than at night-time. Ca and Fe were mostly in the coarse particulate mode. The correlation coefficients were 0.63 and 0.69 for elements Ca and Fe in the coarse particle mode for day and night periods. Pb showed a similar distribution ratio with Mn for the fine to coarse particle ratios at both day and night period. Pb and Mn are highly correlated for the day (R = 0.78) and night period (R = 0.61) at particle size <2.5 microm. Cu and Zn were mainly in fine particles at both day and night period. Fe and Ca consist of the major parts of all the elements. Elemental Mn is the lowest among the rest of the heavy metals.     

水解——好氧——混凝沉淀工艺处理涤纶厂聚酯废水

报道了用上流式厌氧污泥床和生物接触氧化池对涤纶厂聚酯废水所进行的中试。当上流式厌氧污泥床进水ＣＯＤｃｒ浓度为１２００ｍｇ／Ｌ，经水解－好氧工艺处理后，好氧池出水的ＣＯＤｃｒ浓度为１６９．１ｍｇ／Ｌ，进一步混凝沉淀处理后，出水ＣＯＤｃｒ达８０ｍｇ／Ｌ。     

Determination of growth rate and yield of nitrifying bacteria by measuring carbon dioxide uptake rate.

Nitrifier growth parameters--the maximum growth rate (microAmax) and yield (YA)--were estimated by measuring the rate of carbon dioxide uptake and additional rates of oxygen uptake and ammonia (or nitrite) use. Batch tests in a combined titrimetric and offgas analyzer with enriched Nitrobacter and Nitrosomonas cultures and an activated sludge sample were performed. The measured microAmax values for the Nitrobacter and Nitrosomonas cultures were 0.67 +/- 0.03 day(-1) and 0.54 +/- 0.09 day(-1), while the YA values were 0.072 +/- 0.01 g volatile suspended solids (VSS) x g nitrogen (N)(-1) and 0.14 +/- 0.02 gVSS x gN(-1), respectively. For the activated sludge sample, microAmax was observed to increase with pH (microAmax = 0.72 x 3.3(pH-7.1)) over the range 6.8 to 7.1. All microAmax and YA values determined by this method were similar to those previously reported. Compared with other microAmax and YA estimation methods, this method allows for unique microAmax and YA estimations for given conditions from a single experiment.     

Impact of meteorology and energy structure on solvent extractable organic compounds of PM2.5 in Beijing, China

Twenty-eight PM2.5 samples collected in Summer (July 2002) and Winter (November 2002) at two sites in Beijing, China were analyzed using GC/MS to investigate the impact of meteorology and coal burning on the solvent extractable organic compounds (SEOC). The characteristics and abundance of the n-alkanes, polycyclic aromatic hydrocarbons (PAHs), n-fatty acids and n-alkanols were determined. Source identification was made using organic species as molecular markers. Semi-volatile compounds of alkanes and PAHs had much higher concentrations in winter than summer because of the large difference in the temperature between the seasons. Plant wax emission was a major contributor to n-alkanes in summer, but fossil fuel residue was a major source (>80%) in winter. The seasonal differences in the distribution of pentacyclic triterpanes clearly shows the impact of coal burning for space heating in winter. The yield of PAHs in winter (148 ng m(-3) at the urban site and 277 ng m(-3) at the suburban site) was six to eight times higher than that in summer and was found to be mainly from coal burning. Higher pollutant concentrations were measured at the suburban site than the urban site in winter due to the rapid expansion of the city limit and the relocation of factories from urban to suburban areas over the last two decades.     

不同抗生素种类及浓度对麻疯树培养的影响

以麻疯树(jatropha ctrcas)的子叶、真叶、根及其对应的愈伤组织作为实验材料,研究各种抗生素对其生长的影响;在MS培养基中添加不同浓度和不同种类的抗生素,比较其对麻疯树不同外植体及对应愈伤组织生长的影响.方差分析和总体观察的结果表明,用于筛选转化植株的最佳抗生素是卡那霉素,其最佳抗性筛选浓度范围为10～25mg/L.表9参10     

广州生态旅游景观格局建设问题的探讨

通过对生态旅游理论的探讨,对其内涵和外延提出了新的观点。重点对广州风景结构与生态旅游发展背景及存在问题进行了分析,科学地构建了“一山一水六区七廊”的广州生态旅游景观格局,为广州建设生态型山水旅游城市提供依据。加强广州市生态旅游建设,将进一步改善广州的生态环境,优化广州城市景观格局,创造更好的旅游大环境,满足人们日益增长的旅游需求和回归大自然的愿望。     

小麦高分子量麦谷蛋白亚基组成及其对小麦烘烤品质的影响

采用SDS-PAGE方法分析了386份CIMMYT小麦材料的高分子量麦谷蛋白亚基(HMW-GS)组成,并测定了其微量SDS沉降值,同时评估了各亚基对小麦烘烤品质的贡献.电泳结果发现,供试材料所包含的亚基种类和组合非常丰富,共有14条不同亚基和25种不同的亚基组合.A组染色体编码的HMW-GS有Null、Ax1和Ax2,其频率分别为79.50%、16.32%和4.15%;B组染色体编码的亚基按频率由高到低排序为Bx7、Bx7 By9、Bx7 By8、By22、Bx20、Bx14 By15、Bx6 By8,它们的频率分别为42.75%、21.24%、17.36%、13.47%、3.89%、1.04%、0.26%;D组染色体编码的亚基为Dx5 Dy10、Dx2 Dy12、Dx5 Dy12、Dx2 Dy10,其中Dx5 Dy10和Dx2 Dy12亚基为主要类型,频率分别为76.42%和22.00%,含有Dx5 Dy12或Dx2 Dy10亚基的材料非常少,含有Dx5 Dy12亚基的仅有4份,含有Dx2 Dy10亚基的仅有2份,但它们用于研究D染色体编码的等位亚基的遗传和对小麦烘烤品质的贡献将具有重要作用.亚基组合1(Null 5 10 7)出现的频率最高,为34.20%;其次是组合3(Null 5 10 7 9),其频率为11.40%;组合16～25仅分布在1～2份材料中.各亚基对沉降值的影响结果显示,各位点编码的等位基因变异对小麦烘烤品质影响显著.Glu-A1位点上的1亚基的作用显著大于2和Null亚基,2与Null亚基间的差异不显著.Glu-B1位点上的7 8和22亚基显著优于7 9,而7、20和7 9亚基间有差异,但差异不显著,同样,7 8和22亚基间有差异,但差异不显著.5 10和2 12亚基对品质贡献与前人研究一致,5 10亚基显著优于2 12亚基.自然界十分稀少的材料———拥有2 10和5 12亚基的材料的收集对评价Glu-D1位点单个亚基或亚基联合对小麦品质的影响具有十分重要的意义.图1表8参10     

人力资本效能的彰显:激励与约束

人力资本是生产要素中最活跃和最特殊的要素，它的激励与约束问题极为精巧、复杂．本文通过对人力资本激励与约束问题的考察，结合我国体制内企业运营的实践，初步探讨了人力资本激励与约束的机制．     

硝基苯类、氯酚类化合物对金鱼的急性毒性研究

研究了硝基苯类和氯酚类化合物对鲤科金鱼(Carasscas auratus)的急性毒性.结果显示:①硝基苯类化合物随硝基数目在苯环上的增加,其急性毒性增加.②氯酚类化合物的急性毒性随苯环上氯原子数目的增加而增加.通过实验为定量评估和预测同类型化合物的生物急性毒性提供了参考依据.     

核糖体RNA基因在海洋动物分子系统学中的应用

随着分子遗传标记在分子系统学中应用的发展,核糖体RNA基因因其特殊的组成结构和演化方式被广泛应用于海洋动物分子系统学研究中.本文系统地介绍了真核生物核糖体RNA基因的组成和性质及其近年来在海洋动物系统进化、分类和种质鉴定、遗传多样性研究等方面研究中的应用.从中可以看出,核糖体RNA基因已经广泛应用于海洋动物的分子系统学研究中,但主要利用的是核糖体RNA基因的一级结构.图2参36