小城镇环境保护规划现状及对策——以铁岭市八棵树镇为例

小城镇环境保护规划的编制是实现科学发展,积极探索中国农村环境保护新道路的必要举措。文章以铁岭市八棵树镇为典型,通过对环境现状及存在问题的分析,提出了八棵树镇环境保护规划,并为搞好小城镇环保规划和生态建设给出一些合理的对策和建议。     

Anomalous Ba/Ca signals associated with low temperature stresses in Porites corals from Daya Bay, northern South China Sea

Barium to calcium (Ba/Ca) ratio in corals has been considered as a useful geochemical proxy for upwelling, river flood and other oceanic processes. However, recent studies indicated that additional environmental or biological factors can influence the incorporation of Ba into coral skeletons. In this study, Ba/Ca ratios of two Porites corals collected from Daya Bay, northern South China Sea were analyzed. Ba/Ca signals in the two corals were ‘anomalous’ in comparison with Ba behaviors seen in other near-shore corals influenced by upwelling or riverine runoff. Our Ba/Ca profiles displayed similar and remarkable patterns characterized by low and randomly fluctuating background signals periodically interrupted by sharp and large synchronous peaks, clearly indicating an environmental forcing. Further analysis indicated that the Ba/Ca profiles were not correlated with previously claimed environmental factors such as precipitation, coastal upwelling, anthropogenic activities or phytoplankton blooms in other areas. The maxima of Ba/Ca appeared to occur in the period of Sr/Ca maxima, coinciding with the winter minimum temperatures, which suggests that the anomalous high Ba/Ca signals were related to winter-time low sea surface temperature. We speculated that the Ba/Ca peaks in corals of the Daya Bay were most likely the results of enrichment of Ba-rich particles in their skeletons when coral polyps retracted under the stresses of anomalous winter low temperatures. In this case, Ba/Ca ratio in relatively high-latitude corals can be a potential proxy for tracing the low temperature stress.     

川东古代盐业开发对行政区划和城市分布的影响

盐是人类生活的必需品,盐的利用是人类发展史上的一大进步。以前在探讨早期人类活动以地关系时,主要关注温和的气候,宽阔的冲积平原或阶地、弃足的食物来源因素,极少考虑盐的重要性,这是历史学、考古学、地理学、经济的学的空白点。 和根据三峡库区的考古成果,结合对古盐井的考察研究后,认为：川东长江流域地区是井亍开发最早的区域,盐的利用与早期聚落的起源密切相关。手工业、商业从农业分离以后,越界 和为商品利润极高     

西北干旱区城市生态环境规划研究——以内蒙古巴彦浩特为例

生态环境规划与建设是干旱区城市实现区域与城市可持续发展的重要保证，本文以位于腾格里沙漠东部边缘的巴彦浩特为例进行干旱区城市生态环境规划研究。在对巴彦浩特生态环境现状分析的基础上，提出了生态环境保护的目标及原则。运用生态学原理，分析了巴彦浩特城市生态环境规划的主要内容及范围，并提出了实施巴彦浩特生态环境规划的措施及要求。     

巴彦浩特空气质量状况分析

对巴彦浩特地医的空气质量现状及变化趋势进行分析，探讨空气质量变化的原因，并提出治理污染的措施与建议。     

Improving of photocatalytic activity of barium ferrate via bismuth and copper co-doping for degradation of paracetamol under visible light irradiation

Nanosized Ba_{1- x}Bi_xFe_1-xCu_xO₃（12–50 nm） with x values of 0, 0.01, 0.05, and 0.1 system was prepared using the Pechini method. Structural, morphological, surface and optical characterizations were performed for the prepared samples. Cubic phase was the predominant phase for the undoped BaFeO₃ and Bi and Cu co-doped BaFeO₃ samples. Minor phases of monoclinic Ba₂Fe₂O₅, orthorhombic BaFe     

稀土掺杂钨钼酸盐类荧光粉水热法合成及结构与性能的研究

利用水热法制备了A0.925（MoO4）0.5（WO4）0.5∶Dy03.＋05（A=Ca、Sr、Ba）固溶体微晶。通过X射线衍射（XRD）、扫描电镜（SEM）、荧光分析（FA）等测试手段对微晶结构、形貌和发光性能进行了表征。结果表明A0.925（MoO4）0.5（WO4）0.5∶Dy03＋.05（A=Ca、Sr、Ba）复合钨钼酸盐微晶均呈现典型的四方晶相白钨矿结构。荧光光谱中的480nm处的偶合双峰和575nm处的锐而强的黄发射峰,分别对应于稀土离子Dy3＋的4F9/2→6 H15/2和4F9/2→6 H13/2跃迁。其中具有球状颗粒（尺寸为0.7μm）形貌的Ca0.925（MoO4）0.5（WO4）0.5∶Dy03.＋05微晶的发射峰强度最强,在光学材料中具有潜在应用。     

Relationship between plant biodiversity and heavy metal bioavailability in grasslands overlying an abandoned mine

Abandoned metal mines in the Sierra de Guadarrama, Madrid, Spain, are often located in areas of high ecological value. This is true of an abandoned barium mine situated in the heart of a bird sanctuary. Today the area sustains grasslands, interspersed with oakwood formations of Quercus ilex and heywood scrub (Retama sphaerocarpa L.), used by cattle, sheep and wild animals. Our study was designed to establish a relationship between the plant biodiversity of these grasslands and the bioavailability of heavy metals in the topsoil layer of this abandoned mine. We conducted soil chemical analyses and performed a greenhouse evaluation of the effects of different soil heavy metal concentrations on biodiversity. The greenhouse bioassays were run for 6 months using soil samples obtained from the mine polluted with heavy metals (Cu, Zn, Pb and Cd) and from a control pasture. Soil heavy metal and Na concentrations, along with the pH, had intense negative effects on plant biodiversity, as determined through changes in the Shannon index and species richness. Numbers of grasses, legumes, and composites were reduced, whilst other species (including ruderals) were affected to a lesser extent. Zinc had the greatest effect on biodiversity, followed by Cd and Cu. When we compared the sensitivity of the biodiversity indicators to the different metal content variables, pseudototal metal concentrations determined by X-ray fluorescence (XRF) were the most sensitive, followed by available and soluble metal contents. Worse correlations between biodiversity variables and metal variables were shown by pseudototal contents obtained by plasma emission spectroscopy (ICP-OES). Our results highlight the importance of using as many different indicators as possible to reliably assess the response shown by plants to heavy metal soil pollution.     

Ba/TiO2/MCM-41光催化降解对硝基苯甲酸

以钛酸丁酯为钛源、MCM-41分子筛为载体,采用溶胶-凝胶法制备了掺杂与负载相结合的光催化剂Ba/TiO2/MCM-41。结果表明:Ba/TiO2/MCM-41是一种比表面积高达341.2 m2/g的介孔材料,主要晶相为锐钛矿相,比P25有更强的紫外光吸收。将Ba/TiO2/MCM-41用于光催化氧化水中的对硝基苯甲酸,当催化剂投加量为0.5 g/L,对硝基苯甲酸初始pH为4、浓度为2×10-4mol/L时,紫外光照30 min后,对硝基苯甲酸降解率达到96.0%。用紫外光谱、红外光谱和高效液相色谱分析对硝基苯甲酸降解前后的变化,发现随着光照时间延长,苯环上的硝基、羧基吸收峰逐渐减弱;对硝基苯甲酸首先被降解为一些中间小分子产物,随着反应进行,小分子物质也逐渐被降解。     

饮用矿泉水中微量钡的测定方法

采用硫酸钡比浊法测定饮用矿泉水中微量的钡。结果如下：１＋１０硫酸用量以５ｍＬ为最佳;标准曲线相关系数达极显著水准;回收率９５—１０７％;变异系数６４８％;最佳比浊时间为停止搅拌后３０ｍｉｎ内