中国代表性滑雪场网络关注度时空演变及影响因素

基于百度指数数据,运用指数测度、空间地理分析、回归模型和地理探测器,对2011—2019年中国大陆26个代表性滑雪场网络关注度的时空演变特征及影响因素进行分析。结果表明:(1)时间演化上,网络关注度呈先增后减且逐渐平稳的规律。2015年、2016年为峰值年份,季节性差异明显,共两个波动峰值且为“南北为单,中东为双”的分布格局。(2)空间特性上,全国和地区均为先增后减特征,地区差异显著;变异程度先降后增并趋于稳定,全国分布相对稳定平衡,地区分布呈不稳定集聚特性。省区冷热区域分布总体呈“东北热—西南冷”格局,层级变化以稳定型为主。(3)滑雪场层面上,滑雪场总体偏好层级变动较大,高偏好保持稳定领先,其余层级以下降变动为主。滑雪场冷热点分级呈“北热南冷”的格局,东北、华北两个热点集聚区域演变较为稳定。(4)影响因素上,需求侧影响因素排序为滑雪消费吸引力>受教育程度>经济发展水平>信息化水平>滑雪场建设水平。供给侧的滑雪人次占比、滑雪经济贡献、客运承载力、冰雪旅游资源丰度、官方媒体建设水平解释力较强,其他因素影响并不显著。     

废橡胶粉对混合砂浆性能影响的研究

系统测试和分析了新拌混合砂浆和易性和硬化砂浆轴心抗压强度、静力受压弹性模量、泊松比、干表观密度、导热系数、干燥收缩率随三元乙丙(EPDM)橡胶粉代砂体积分数增加的变化程度和规律.橡胶粉可以改善新拌混合砂浆的和易性,降低硬化混合砂浆强度、弹性模量、表观密度和导热系数,提高其泊松比和干燥收缩率.低弹性模量、高泊松比、高干缩值橡胶粉混合砂浆将使其更能适应新型墙体材料性能的要求,有利于减小墙体裂缝的产生;低表观密度、低导热系数橡胶粉混合砂浆将有利于提高墙体的隔热保温性能.     

气体快速定性技术在气态污染物突发性污染事故应急监测中的应用

介绍气体快速定性技术在气态污染物突发性污染事故应急监测中的应用.使用北川式无机气体定性检测管、有机气体定性检测管进行事故现场气体快速检测,简述上述检测管的使用技术及检测人员在事故现场应采取的防护措施.     

Measurement of selected indoor physical environmental factors in hairdresser salons in a Turkish City

Objectives The purpose of this study was to determine electromagnetic fields, electric fields, humidity, temperature, and illumination levels in hairdresser salons located in the downtown area of Aydin, Turkey. Also some health problems which could be related with the occupational factors are evaluated. Materials and methods The study was carried out in 30 hairdresser salons, all of which had been registered within the past 5 years. Electric and electromagnetic fields, illumination, temperature and humidity measurements were determined for hairdryers, hood hairdryers and depilatory heaters in the participating salons. A brief questionnaire about characteristics and the health status of hairdressers and workplace conditions was prepared and administered to the hairdressers at the salons. Results The mean electric fields of hairdryers, hood hairdryers and depilatory heaters were determined as 518 ± 74, 1,123 ± 199, and 648 ± 146 in V/m, respectively, at 5 cm from the surface of each device. These appliances generate mean electromagnetic fields in excess of 0.25 μT at 5 cm: hand-held hairdryers, 5.0 ± 0.7 μT; hood hairdryers, 1.6 ± 0.3 μT; and depilatory heaters 1.9 ± 0.6 μT. Total average of cumulative electric and electromagnetic fields, measured at a distance of 90 cm from the surface of these three devices was calculated to be 98.8 V/m and 0.5 μT, in the participating salons. Conclusions This preliminary study suggests that physical environmental factors in the salons may be contributing to the health problems of the hairdressers, and the electrical equipments in the workplaces may have cumulative electric and electromagnetic effects.     

Hydraulic performance of Compacted Clay Liners (CCLs) under combined temperature and leachate exposures

Experimental investigations were carried out to investigate the effect of thermo-chemical exposures on the hydraulic performance of Compacted Clay Liners (CCLs) in landfills. Hydraulic conductivity of most CCL specimens was increased by two to three times their initial values when exposed to 55 °C for 75 days. CCL specimens also experienced increases in their hydraulic conductivities when exposed to leachate at room temperature. This behaviour could be due to the decrease in viscosity when the permeant was changed from tap water to leachate. However, as the leachate exposure time exceeded the first 15 days, hydraulic conductivity readings decreased to as much as one order of magnitude after 75 days of leachate permeation at room temperature. The gradual decrease in the CCLs hydraulic conductivities was most likely due to chemical precipitation and clogging of pore voids within the soils which seemed to reduce the effective pore volume. The rate of hydraulic conductivity reduction due to leachate permeation was slower at higher temperatures, which was attributed to the lower permeant viscosity and lower clogging occurrence. The observed hydraulic behaviours were correlated to the physical, mineral, and chemical properties of the CCLs and described below.     

生活污水电导率与CODcr的相关性分析

CODcr标准测定方法测定时间较长,氯离子干扰较大.通过对生活污水电导率的测定,归纳出电导率与CODcr的相关性,在基层环境监测中较适用.     

浮油自动回收设备两例

油和水物理性能的差异是设计浮油回收设备的基础。依据两者导电率差异研制出全自动浮油回收机,适用于粘度较低的浮油回收。利用两者粘度的不同,生产出收油效率较高的盘片式自动浮油回收设备,特别适合于粘度较高的浮油回收。     

有毒有害气体检测报警仪的选择和使用

详细介绍了如何选择合适的有毒有害气体检测报警仪，提出了在使用过程中需要注意的问题。     

烟气净化用防腐涂料导电特性的实验研究

对电晕放电烟气净化设备用防腐涂料的导电特性进行了实验研究,涂层导电机理为渗流、隧道效应和场致发射综合作用。涂层比电阻随填料粒度的增大,添加量的增加显著下降。随温度增加,涂层比电阻有所上升,在95～110℃以后下降。涂料的比电阻为103～104Ω.cm量级。     

HACH仪器法与回流法测定COD的对比实验

化学需氧量测定方法是否快捷、准确,决定了水质监测/检验的工作效率及数据的可靠性.HACH仪器法操作简单、数据可靠,具有测定范围广、试剂用量小、对环境二次污染小等优点.