基于层次分析法的古村落旅游资源评价——以世界遗产地西递、宏村为例

以世界遗产地皖南古村落——西递、宏村为研究区域,从研究区域的资源价值和区位条件两个方面,选取了5个Ⅰ级指标：历史文化价值、科学价值、艺术价值、区域规模、交通便利程度,12个Ⅱ级指标：年代久远程度、民俗代表性、历史事件名人影响度、科学考察、科普教育、完整性、典型性、观赏性、地域组合、环境容量、通达性与服务中心距离,建立评价指标体系,并结合YAAHP软件对该指标体系进行层次分析,得出了各指标的相对权重。结果表明,西递、宏村的历史文化价值与艺术价值在其旅游资源评价中具有重要地位。在此基础上对其进行了分析并提出了相应的保护措施和对策,以期达到对西递、宏村旅游资源合理保护与开发的目的。     

关于重金属污染治理的几点思考

重金属污染正在被人们关注,重金属污染引发的社会环境问题显得尤为突出,隆昌县作为重金属污染重点防控区域,通过对存在问题的分析,提出了相应的治理对策。     

拟开发场地的土壤重金属污染调查与评价实践

土壤污染调查乃"土壤修复"的前期。在某市郊拟开发建设的场地,按8个点分三层采集了24个土壤样品,用原子吸收光谱法测定样品中汞、铅、镉、铜、锌、镍、铬等7种重金属元素的含量,汞呈现对数正态分布,其他元素为正态分布,各元素在土壤层水平分布状态和垂直分布水平的差异性不显著,锌含量水平现状值在《土壤环境质量标准》GB15618-1995二级标准的指标限值内,汞、铅、镉、铜、镍、铬含量水平现状值均在土壤环境质量一级标准的指标限值内,且各元素浓度水平现状值均与场地所在区域土壤背景值一致。由此,本调查的场地土壤环境现状没有受到铅、汞、镉、铜、锌、镍、铬金属元素污染。     

Environmental Suitability and Durabiity Validation of Automotive Electronic and Electric Components

本文介绍了汽车电子电器零部件开发过程中的环境适应性和可靠性验证方法.主要通过对开发过程中各个阶段验证情况的研究,分析了现在车厂对汽车电子电气零部件的试验目标、试验项目及试验时间的设定方法,为车载电气零部件的环境适应性和可靠性验证提供依据.     

电器防雷滤波技术探讨

我国是雷电多发地区,在我们日常生活中电器经常会被雷电击坏或不能正常工作。本文就产品设计中我们常采用的一种既防雷又解决滤波的防雷滤波技术讨论,并加以验证。     

Cornmeal-induced resistance to ciprofloxacin and erythromycin in enterococci

Triclosan is used as an antibacterial agent in household items and personal care products. Since this compound is found in maternal milk of humans and bodies of wild animals, there is growing concern among some consumer groups and scientific community that triclosan is adverse for humans and wild animals. In order to estimate adverse actions of triclosan, the effects of triclosan on intracellular Zn²⁺ concentration and cellular thiol content were studied in rat thymocytes by the use of flow cytometer with appropriate fluorescent probes. Triclosan at 1-3 μM (sublethal concentrations) increased the intensity of FluoZin-3 fluorescence (intracellular Zn²⁺ concentration) and decreased the intensity of 5-chloromethylfluorescein (5-CMF) fluorescence (cellular thiol content). Negative correlation (r = −0.985) between triclosan-induced changes in FluoZin-3 and 5-CMF fluorescences was found. Removal of external Zn²⁺ did not significantly affect the triclosan-induced augmentation of FluoZin-3 fluorescence, suggesting an intracellular Zn²⁺ release by triclosan. These actions of triclosan were similar to those of H₂O₂ and triclosan significantly potentiated the cytotoxicity of H₂O₂. Therefore, the results may suggest that triclosan at sublethal concentrations induces oxidative stress that decreases cellular thiol content, resulting in an increase in intracellular Zn²⁺ concentration by Zn²⁺ release from intracellular store(s). Since recent studies show many physiological roles of intracellular Zn²⁺ in cellular functions, the triclosan-induced disturbance of cellular Zn²⁺ homeostasis may induce adverse actions on the cells.     

Chronic toxicity of copper on embryo development in Chinese toad, Bufo gargarizans

This study examined the effects of copper exposure on embryonic development of Chinese toad, Bufo gargarizans. Firstly, the LC₅₀ values from 24 to 96 h of exposure were 3.61 × 10⁻⁶ M, by means of a 4 d toxicity test with B. gargarizans embryos. Secondly, Chinese toad embryos were exposed to 10⁻⁹-10⁻⁶ M copper from mid gastrula stage to operculum completion stage. Measurements included mortality, tadpole weight, tadpole total length, growth retardation, duration of different embryo stages and malformation. Embryonic survival was not affected by copper. Relative to control tadpoles, significantly decreased weight and total length were found at 10^-9-10^-6 M reduced percentage of the embryos in right operculum stage after 10 d exposure to copper and reduced percentage of embryos in operculum completion stage after 12 d exposure to copper were also observed. Moreover, the duration of embryonic development increased at neural, circulation and operculum development stage in copper-treated groups. For the scanning microscope and histological observation, the abnormalities were malformation of wavy dorsal fin, flexural tail, curvature body axis, yolk sac oedema and reduced pigmentation in the yolk sac. Histopathological changes in olfactory, retinal epithelium and skin were also observed. DNA strand breaks exposed to the copper were analyzed by DNA ladder. In conclusion, copper induced toxic effects on B. gargarizans embryos. The present study indicated chronic toxicity tests may provide more accurate way in formulating the “safe levels” of heavy metals to amphibian.     

百色市右江区大气PM10中水溶性无机离子的化学特征与来源

2010年10月至2011年9月采集百色市右江区大气PM10样品,分析PM10及其水溶性无机离子的化学特征与来源。结果表明:(1)百色市右江区大气PM10为13.89～319.44μg/m3,年均117.48μg/m3,年均值超过《环境空气质量标准》(GB 3095-2012)二级标准(100μg/m3)。百色市右江区大气可吸入颗粒物的污染主要出现在春冬季节。(2)水溶性无机离子浓度年均值依次为SO24->NO3->Cl->NH4+>K+>Na+>Mg2+>F-,SO24-、NO3-和Cl-浓度最高,分别占水溶性无机离子的57.7%、14.9%和14.5%。(3)百色市右江区大气PM10呈较强的酸性,高浓度的SO42-可能是导致百色市右江区大气PM10呈较强酸性的主要原因。(4)PM10的季节变化受气温和风速的影响极显著;气象因素对SO42-、NO3-、F-的影响不显著。(5)主因子分析表明,PM10中水溶性无机离子可能来自3个方面,Cl-和NO3-主要来自于当地低烟卤煤燃烧排放的烟气;Mg2+、K+和Na+主要来自于自然源;F-、SO24-和NH4+主要来自于混合源。     

三垟湿地沉积物-间隙水-上覆水界面磷形态研究

沉积物与上覆水间营养物质交换,成为导致水体发生富营养化的首要化学变迁过程.分别在三垟湿地的柑橘林(S1)、景观用地(S2)和生活用地(S3)取样,研究了沉积物-间隙水-上覆水界面磷形态以及相互关系.结果表明:(1)沉积物TP增加时,间隙水PO3-4和可溶性总磷(TDP)也增加.要削减磷在上覆水中的含量,控制间隙水PO3-4或TDP是一良策.(2)随着沉积物铁磷、铝磷的增加,间隙水PO3-4也增加.在三垟湿地沉积物中,铁磷和铝磷含量都可作为间隙水PO34-含量的指示.(3)S1、S2和S3的沉积物活性磷、间隙水TDP和上覆水TDP存在明显的浓度梯度,沉积物活性磷＞间隙水TDP＞上覆水TDP.说明在三垟湿地中,沉积物活性磷是磷释放的关键因子,而沉积物-间隙水界面则是磷释放的关键界面.     

三氯乙烯在苯酚菌中的共代谢降解性能研究

通过生物降解实验考察三氯乙烯(TCE)在苯酚驯化微生物中的共代谢降解性能,并进行动力学分析。结果表明,苯酚是TCE-苯酚共代谢过程必不可少的共代谢基质;TCE的共代谢降解与苯酚和TCE初始浓度有关。TCE在降解初期会出现一个短暂的迟滞期,TCE的大量降解要在苯酚被利用后才发生;高质量浓度TCE(>9mg/L)对共代谢降解有抑制作用。苯酚/TCE(质量比)在10～15以上时,苯酚菌对TCE的去除率较大。Haldane模型能够很好地拟合苯酚和TCE的比降解速率。动力学分析表明,微生物对苯酚的亲和力要大于TCE,苯酚对TCE共降解具有竞争性抑制作用,TCE对微生物存在毒性抑制作用;结果证实了生物降解实验的结论。