基于张家界市环境质量变化的生态环境建设对策

本文通过对“九五”期间张家界市的生态环境质量进行回顾性分析评价,在掌握其区域自然特征和生态环境现状的基础上,运用环境科学的基本理论分析了张家界市环境质量变化原因和趋势,指出了张家界市存在的主要生态环境问题,并提出了若干对策来引导张家界市的生态环境建设,以实现其建设生态城市的宏伟目标.     

空肠弯曲菌的快速检测方法研究与应用

为提高空肠弯曲菌的检测效率和检出率，应用免疫磁珠技术自行制备弯曲菌免疫磁珠，用以直接捕获受检样品中的空肠弯曲菌，不需要增菌培养；设计了检测空肠弯曲菌鞭毛蛋白A（flaA）基因的引物与荧光标记探针，首次建立了空肠弯曲菌的磁捕获-荧光聚合酶链式反应快速检测及鉴定方法．应用于实物检测的结果表明，该方法具有灵敏度高、选择性好、简便等特点，可在24h内完成检测，提高了环境样品及食品中空肠弯曲菌的检出率．图4表1参9     

A Bayesian hierarchical model for monitoring harbor seal changes in Prince William Sound, Alaska

Bayesian hierarchical models were used to assess trends of harbor seals, Phoca vitulina richardsi, in Prince William Sound, Alaska, following the 1989 Exxon Valdez oil spill. Data consisted of 4–10 replicate observations per year at 25 sites over 10 years. We had multiple objectives, including estimating the effects of covariates on seal counts, and estimating trend and abundance, both per site and overall. We considered a Bayesian hierarchical model to meet our objectives. The model consists of a Poisson regression model for each site. For each observation the logarithm of the mean of the Poisson distribution was a linear model with the following factors: (1) intercept for each site and year, (2) time of year, (3) time of day, (4) time relative to low tide, and (5) tide height. The intercept for each site was then given a linear trend model for year. As part of the hierarchical model, parameters for each site were given a prior distribution to summarize overall effects. Results showed that at most sites, (1) trend is down; counts decreased yearly, (2) counts decrease throughout August, (3) counts decrease throughout the day, (4) counts are at a maximum very near to low tide, and (5) counts decrease as the height of the low tide increases; however, there was considerable variation among sites. To get overall trend we used a weighted average of the trend at each site, where the weights depended on the overall abundance of a site. Results indicate a 3.3% decrease per year over the time period.     

无火焰泄放装置性能检测技术研究*

为有效提高无火焰泄放装置产品质量特性和应用技术,避免或减轻爆炸事故发生造成的灾害程度,选择玉米淀粉粉尘为测试粉尘,采用1 m3爆炸罐进行扇形无火焰泄放装置爆炸泄放实验。结果表明:扇形无火焰泄放装置不适合重复使用。当扇形无火焰泄放装置重复进行爆炸泄放实验时,爆炸罐内压力会呈现升高趋势,而外场压力和温度呈现下降趋势,且阻火元件孔隙内残留大量玉米淀粉粉尘燃烧后生成的炭黑以及积聚部分高温燃烧的粉尘,致使阻火元件损坏失效。     

基于深度学习的输煤皮带故障视觉检测方法研究

为了更好地检测皮带跑偏、撕裂和异物干扰等严重影响皮带安全运行的故障状态,围绕相关问题产生的原因及检测方法开展深入研究,通过对纵/横向裂缝、异物的检测分析、实验,提高基于视觉的检测精度。提出基于Canny边缘检测算法的皮带跑偏检测算法;基于深度学习的横向与纵向撕裂检测,尤其对于裂缝与纵向纹理区分不明显情况,提出一种红光透射的判别方式;基于最小距离分类算法将识别异物转换为分类问题,利用机器学习的方法对样本进行训练并建立无异物阈值,通过提取特征,最后利用最小距离分类算法得到有无异物的结果。研究结果表明:提出的视觉检测系统可以实时高效地检测出输煤皮带常见的3种故障,可进一步保障运输系统安全运行。     

近40年来长江流域水沙变化趋势及可能影响因素探讨

利用Mann Kendall方法,分析了近40年长江流域主要水文站点（长江干流水文站：屏山站、宜昌站、汉口站与大通站;支流水文站：嘉陵江的北碚站和汉江的皇庄站）的流量及输沙率的变化特征。结果表明：①长江流域流量与输沙量变化受人类活动（土地利用、水利设施建设等）与自然因素（如降水的时空变化）综合因素影响,变化趋势表现出复杂性,上、中、下游各有特点;②长江流域屏山站以上流域输沙率有上升趋势（1~5月份上升趋势达到95%的置信度水平）,这与上游河床坡度较大,使泥沙不易沉积以及暴雨与降水增加有关;③长江中下游输沙呈显著下降趋势。计算结果表明,宜昌-汉口河段是长江流域泥沙主要沉积区,加上葛州坝与三峡工程的建成与投入使用,从而进一步使中下游输沙量呈下降趋势。由于下游降水增加,使下游径流量自1980s以来有微弱上升趋势,但未达到95%的置信度水平,中上游流量变化不显著。对上、中、下游人为因素与自然因素对流域流量与输沙量的变化贡献率方面需要做进一步的研究。     

呼和浩特市十年来环境空气污染趋势分析

通过对呼和浩特市10年的环境空气监测数据进行分析,结果表明,二氧化硫、总悬浮颗粒物呈下降趋势,二氧化氮变化不大,尘是影响呼市环境空气质量的主要污染因子,并提出了改善呼市大气环境质量的对策。     

Historical trends of PCBs and PBDEs as reconstructed in a lake sediment from southern Tibetan Plateau

High-altitude lake sediment can be used as a natural archive to reconstruct the history of pollutants. In this work, the temporal distribution of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined using a high-resolution gas chromatography coupled with high-resolution mass spectrometer (HRGC/HRMS) in an alpine lake sediment core collected from the southern Tibetan Plateau (TP) to examine whether the expected decreasing trends due to the implementation of the international Conventions could be observed. The concentrations of PCBs and PBDEs in the sediment core were in the range of 11.8–142 pg/g dw and ND-457 pg/g dw, and their fluxes were in the range of 2.51–31.7 ng/(m²·yr) and ND-43.2 ng/(m²·yr), respectively. The prevalence of low-chlorinated (tri-CB) PCBs and low-brominated (tri- to tetra-) PBDEs in most sections of the sediment profiles was observed, suggesting that the light molecular weight PCBs and PBDEs have most likely reached lake sediments by long-range atmospheric transport from distant sources. Despite the restrictions on their applications, the sediment records for the concentrations and fluxes showed no corresponding decreasing trend with restrictions for PCBs, which suggested that these POPs (e.g., PCBs) were still emitted to the environment owing to the influence of primary or secondary emissions. To our knowledge, this is the first report on input history of atmospheric PCBs and PBDEs recorded in TP Lake sediment.     

基于平面波导传感器的恩诺沙星与诺氟沙星同时检测方法

为了实现对于环境中抗生素恩诺沙星与诺氟沙星的同时快速灵敏检测,本研究基于间接竞争免疫反应模式及荧光全内反射原理,以本课题组自主研发的平面波导生物传感器为平台,建立了恩诺沙星和诺氟沙星的同时快速检测方法.通过对抗体浓度、pH及钙离子浓度的优化,提高了检测方法的灵敏度,结果表明,恩诺沙星的检测限为0.34μg·L~(-1),诺氟沙星的检测限为0.14μg·L~(-1).在单物质检测的基础上,首次实现了基于平面波导传感器的两种抗生素同时检测,检测周期仅15 min,检测限为0.06μg·L~(-1).本研究从理论上分析了同时检测时检测限下降、灵敏度提高的原因,为利用生物传感器法同时检测抗生素提供了理论指导及技术支撑.     

气候变化下汉中盆地水稻产量变化研究

深入分析气候变化下汉中盆地水稻产量变化响应,可在进一步探究影响研究区水稻产量主要气象要素的同时,为地方水稻生长期内气象灾害的防控提供科学依据。为了解研究区水稻生长季主要的气象影响因子,文章基于1951—2014年汉中盆地多测站日气温、降水量、积温及气温日较差数据和水稻单产资料分离的气象单产数据,综合运用线性趋势、趋势系数、HP滤波法、Morlet小波分析等方法,在分析汉中盆地水稻气象产量和生长季各气象要素变化趋势的同时,推求了水稻气象产量和各主要气象要素序列的显著周期。研究结果表明：1）近64 a汉中盆地4—9月水稻生长季平均气温和≥10 ℃活动积温变化均呈上升趋势,气温日较差呈下降趋势,降水量变化趋势不明显;2）汉中盆地各气象要素与水稻气象单产的显著周期分析结果显示水稻气象单产第一主周期与各气象要素的第二主周期相对应,均存在13~14 a时间尺度的主周期变化;3）各气象要素对水稻气象产量的影响各异,不同气候背景下影响水稻气象产量的主导气象因素不同。论文研究结果可为汉中盆地水稻生产的优化布局及地方经济社会发展提供参考依据。