Hiking Trails and Tourism Impact Assessment In Protected Area: Jiuzhaigou Biosphere Reserve,China

More and more visitors are attracted to protected areas nowadays, which not only bring about economic increase but also seriously adverse impacts on the ecological environment. In protected areas, trails are linkage between visitors and natural ecosystem, so they concentrate most of the adverse impacts caused by visitors. The trampling problems on the trails have been received attentions in the tremendous researches. However, few of them have correlated the environmental impacts to trail spatial patterns. In this project, the trails were selected as assessment objective, the trampling problems trail widening, multiple trail, and root exposure were taken as assessment indicators to assess ecological impacts in the case study area Jiuzhaigou Biosphere Reserve, and two spatial index, connectivity and circularity, were taken to indicate the trail network spatial patterns. The research results showed that the appearing frequency of the trampling problems had inverse correlation with the circularity and connectivity of the trail network, while the problem extent had no correlation with the spatial pattern. Comparing with the pristine trails, the artificial maintenance for the trails such as wooden trails and flagstone trails could prohibit vegetation root from exposure effectively. The research finds will be useful for the future trail design and tourism management.     

环境监理在海洋环境保护中的作用

阐述了开展海洋环境监理工作意义，论述了海洋环境监理的任务介绍了本地区开展海洋环境监理工作的经验。     

Distribution and sources of polycyclic aromatic hydrocarbons in the water column of Kongsfjorden, Arctic

Kongsfjorden is known for its characteristic multi-layer water mass formed by the convergence of freshwaters from nearby glaciers and rivers and saline water from the Atlantic and Arctic. The distribution of polycyclic aromatic hydrocarbons (PAHs) in the water column of Kongsfjorden was investigated and their potential sources were analyzed. The total concentrations of 16 PAHs in the surface seawater and river water were in the range of 33.4?79.8 ng/L (mean 48.5 ng/L) and 2.3?201.4 ng/L (mean 126.1 ng/L), respectively. Horizontally, PAHs were mainly concentrated around river estuaries and the glacier front in the dissolved phase. Vertically, the PAHs in the particulate phase followed surface-enrichment and depth-depletion patterns in most stations, with the maximum concentration found at 50 m depth in the central area of Kongsfjorden. The compositions of PAHs in seawater and rivers were similar, with two-ring and tricyclic PAHs comprising the majority of the dissolved and particulate phases. PAHs found in Kongsfjorden waters appeared to be derived from multiple sources such as petroleum and coal combustion. PAHs in the bay mouth of Kongsfjorden were mainly introduced by the West Spitsbergen Current and the Arctic waters, while in the inner bay, atmospheric deposition and local sources were the major contributors. The distribution of PAHs was mainly attributed to the suspended particulate distribution.     

VxMn(4 − x)Mo3Ce3/Ti catalysts for selective catalytic reduction of NO by NH3

A series of vanadium based catalysts(VxMn(4-x)Mo3Ce3/Ti) with different vanadium(x wt.%) and manganese((4-x) wt.%) contents have been prepared by the wet impregnation method and investigated for selective catalytic reduction(SCR) of NO_x by NH_3 in the presence of 8 vol.% H_2O and 500 ppm V SO_2.The physicochemical characteristics of the catalysts were thoroughly characterized.The SCR of NO_x by NH_3(NH_3-SCR) activity, especially the low-temperature activity, significantly increased with increasing V_2O_5 content in the catalyst until the V_2O_5 content reached 1.5 wt.%, which corresponds well with the redox properties of the catalyst.All of the metal oxides were well dispersed and strongly interacted with each other on the catalyst surface.V mainly exists in the V~(5+)state in the catalysts.The strong synergistic effect between the vanadium and cerium species led to formation of more Ce~(3+)species, and that between the vanadium and manganese species contributed to formation of more manganese species with low valences.All of the catalysts exhibited strong acidity, while the redox properties determined the NH_3-SCR activity, especially the low-temperature activity.H_2O and SO_2 had severe inhibiting effects on the activity of V1.5Mn2.5Mo3Ce3/Ti.However, good H_2O and SO_2 resistance and high NO_x conversion by V1.5Mn2.5Mo3Ce3/Ti could be achieved in the presence of SO_2 and almost no decline was observed in a long-term test at 275℃ for 168 hr in the presence of SO_2 and H_2O, which can be attributed to the sulfate species formed on the catalyst surface.     

潜流人工湿地堵塞程度的原位测定研究

人工湿地因其生态友好、运行费用低廉、处理效果好而被广泛运用于污水处理中,然而潜流人工湿地在运行过程中会发生填料堵塞,导致其利用率下降、寿命缩短,但目前还缺乏简单有效的原位测定人工湿地堵塞程度的方法和仪器.为了客观地评价湿地的堵塞程度,以渗透系数法为测定原理构建了人工湿地堵塞程度原位测定法,结合压力探测和数据处理模块开发了人工湿地堵塞程度原位测定仪,并进行了实验室试验和原位测量以检验方法和仪器的可行性.实验室试验中测量了利用砂土和砾石模拟的不同程度的堵塞.结果表明:当填料砂土与砾石的质量比为2:1、4:1、8:1时,堵塞系数分别为0.69、0.84、0.91 km/d,测得的堵塞系数和填料比例显著相关,能够准确地反映堵塞程度.原位测量选择运行了1~5 a的4个潜流人工湿地（A、B、C、D湿地）进行,运行一段时间后,潜流人工湿地入口处、湿地管道破损处和使用时间较长的湿地堵塞系数较高,最高达0.998 km/d,而运行情况良好的D湿地堵塞系数在0.5 km/d以下.研究显示,原位测定结果能很好地反映湿地的堵塞情况.      

水污染源在线设备比对监测问题与解决方案——以长沙市在线监测系统为例

总结了长沙市7年来水污染源在线监测系统开展比对监测工作的情况,对氨氮、p H、重金属比对监测存在的问题进行了剖析,分析了在线监测仪器比对不合格的原因以及目前在线监测仪器部分项目缺乏误差标准等亟待解决的问题,研究出各因子误差的合理区间,提出了切实可行的解决方案:氨氮应该按照检测浓度高低确定误差范围;p H质控样不应使用相对误差,建议采用±0.3 p H的绝对误差;重金属实际水样浓度小于一定量时,用接近水样浓度的低浓度质控样替代。     

惰化降温耦合作用下的采空区低温CO2注入流量与温度研究

为了更好地使用LCO_2预防采空区煤自燃安全事故,结合宣东二号煤矿Ⅲ3煤层209工作面的实际条件,利用FLUENT数值模拟的方法,分别研究了低温CO_2的不同注入流量与温度对采空区氧化带内最高点温度、氧化带宽度和最大高温区域温度的影响。发现随着注入流量的增大,氧化带宽度与温度先逐渐下降后趋于平缓,注入温度的下降对回风侧高温点影响不大,而能将入风侧采空区最大高温区域温度降低。研究表明,注入流量增大到一定程度后对缩小采空区氧化带宽度的作用变小,而注入温度的下降对回风侧存在高温发火危险的采空区降温效果不佳。     

基于层次分析的平江县村镇建设用地适宜性评价研究

为实现土地的可持续利用,以平江县为例,采用层次分析法(AHP法),选择了自然生态、生态安全、社会经济三大类因素和高程、坡度、坡向、自然灾害、基本农田、生物生境、交通区位、水文区位和城镇吸引力9个指标,建立了村镇建设用地适宜性评价指标体系,分析了村镇建设用地适宜性评价中三大因素之间的关系和9个指标之间的重要性.结果表明,城镇建设用地适宜性评价中,权重最大的是生态安全因素,所以城镇建设必须从保护生态安全格局出发,进行科学规划;自然灾害指标合成权重最大,是城镇建议用地规划着重考虑的指标.层次分析法是系统的分析方法,为村镇建设用地的选择提供了数据依据.     

基于BP神经网络的天津市PM2.5浓度预测研究

根据天津市2013年12月1日-2013年12月24日气象监测数据,先进行温度、湿度、风力因素对PM2.5浓度影响的相关性分析及定性分析,绘制温度、湿度和PM2.5浓度的二维趋势分布图及气体扩散风向浓度分布图;再运用BP神经网络模型对天津市2013年12月25日-2014年1月9日PM2.5浓度进行仿真预测,最终得到精确预测值.结果表明:温度及风速因素与PM2.5的浓度成反比,湿度因素与PM2.5的浓度成正比,而且通过BP神经网络模型对于“离散样本”、“气象参数不确定性”的实际天气情况可以得到较高的预测精度.     

中国中老年男性全血比粘度参考值与海拔高度的曲线模型分析

目的：为制定中国中老年男性全血比粘度参考值的统一标准提供科学依据,方法：收集了中国３１２个单位用毛细管法测定的２１２７７例健康中老年男性全血比粘度参考值,用曲线回归分析的方法研究了其与海拨高度之间的关系。结果：发现随着海拨高度的逐渐增大,中老年男性全血比粘度参考值按指数律也在逐渐的增大,相关性很显著（Ｒ＝０．７８４）;推导出了一个曲线回归模型＾Ｙ＝４３５×１０００１２９ｘ±０９３。结论：如果知道了中国某地的海拨高度,就可以用回归模型估算这个地区的中老年男性全血比粘度参考值,依据中老年男性全血比粘度参考值与地理因素的依赖关系把中国分为青藏区,中部区,东部区等三个区