MATLAB加VB实现实验室质量控制图的绘制

阐述了质量控制图在实验室质量控制中的作用和存在的问题,提出应用Visual Basic的界面设计功能,以及MATLAB的计算和图形处理功能,通过在VB中以ActiveX组件方式调用 MATLAB对象的属性和方法,实现质量控制中复杂的数据统计和图表的制作功能.并对《环境水质监测质量保证手册》中的各类质控图进行了实例示范.     

Comparing Onsite and Offsite Methods for Measuring Norms for Trail Impacts

This study examined the comparability of onsite and offsite methods for measuring norms for trail impacts using photo/survey techniques. A total of 449 subjects participated in a study of Mudeung-Mountain Provincial Park, Gwang-Ju, Korea. For the overall photo evaluation method (OPEM), respondents rated the acceptability of bare soil area for each of a series of photographs. For the specific photo evaluation method (SPEM), respondents selected a photograph that illustrated the largest acceptable proportion of bare soil area from a series of 10 photographs. Overall, there were no substantial differences in maximum acceptable impacts between onsite (onsite-I visitor group surveyed at the actual trail points and onsite-II departing visitor group surveyed at the exit area) and offsite (students surveyed in a laboratory setting) groups for the two norm measurement alternatives (OPEM and SPEM). Subjects’ difficulty ratings were low for both methods, and there were no substantial differences in norms between individuals with high and low levels of experience at the park. The offsite method appears to be substitutable for onsite methods in this particular study area, which is a frontcountry setting with a relatively simple range of recreation opportunities. Implications and further studies are discussed.     

天然土壤有机质中菲的分配行为

天然土壤吸附不同初始浓度的菲后,提取胡敏酸组分(包括胡敏酸和富里酸),通过计算得到胡敏素组份所吸附的菲,用以研究菲在2种组份中的动态吸附/分配行为,以及初始浓度的影响,并利用Freundlich式进行拟合.结果表明:天然土壤中菲的吸附/分配过程表现出分阶段特征:从最初的快吸附至48 h左右达到转折点,然后进入慢吸附过程.在快吸附至转折点阶段,胡敏酸组分中菲的吸附比例(吸附量与初始量之比)出现先升后降的波动,可归因于初始时段矿物表面吸附、胡敏素竞争吸附的影响.在慢吸附阶段,胡敏酸中菲的吸附比例变化很小,菲初始浓度的影响也不大;而对于胡敏素组份,低初始浓度条件下菲的吸附比例明显大于高初始浓度条件,并呈现逐步增加的趋势,表明胡敏素组份是慢吸附的主要发生域.模型参数拟合结果显示:胡敏酸、全土、胡敏素吸附的非线性程度依次增加,并随时间逐渐加强.在吸附/分配的动力学过程中,胡敏酸和胡敏素分阶段不同的变化特征反映出土壤有机质组分异质性对非线性吸附行为的影响.     

基于短时傅里叶变换的飞行器故障振动信号分析

目的 对某飞行器出现故障时的振动信号进行分析,为故障定位提供依据.方法 将短时傅里叶变换方法 应用于飞行振动信号分析,通过计算故障振动信号和正常振动信号的短时傅立叶变换谱,获取两者之间的不同时频特征.通过分析包括发动机工作、外部气动激励、设备工作、电气干扰在内的各种影响因素的时频变化特征,与故障振动信号的时频特征对比,...     

Supercritical gasification for the treatment of o-cresol wastewater

The supercritical water gasification of phenolic wastewater without oxidant was performed to degrade pollutants and produce hydrogen-enriched gases. The simulated o-cresol wastewater was gasified at 440-650℃ and 27.6 MPa in a continuous Inconel 625 reactor with the residence time of 0.42-1.25 min. The influence of the reaction temperature, residence time, pressure, catalyst, oxidant and the pollutant concentration on the gasification efficiency was investigated. Higher temperature and longer residence time enhanced the o-cresol gasification. The TOC removal rate and hydrogen gasification rate were 90.6% and 194.6%, respectively, at the temperature of 650℃ and the residence time of 0.83 min. The product gas was mainly composed of H2, CO2, CFL and CO, among which the total molar percentage of H2 and CFL was higher than 50%. The gasification efficiency decreased with the pollutant concentration increasing. Both the catalyst and oxidant could accelerate the hydrocarbon gasification at a lower reaction temperature, in which the catalyst promoted H2 production and the oxidant enhanced CO2 generation. The intermediates of liquid effluents were analyzed and phenol was found to be the main composition. The results indicate that the supercritical gasification is a promising way for the treatment of hazardous organic wastewater.     

央企生态环境保护督察机制探究

为进一步推进生态文明建设和监管机制改革,党中央、国务院决定将中央管理企业(央企)纳入第二轮生态环境保护督察范畴.对央企生态环境保护督察机制开展研究,梳理了央企生态环境保护保责任清单,从督察对象、督察事项和督察模式等方面探究了央企生态环境保护督察路径,并提出央企生态环境督察成效保障相关建议:采用宏观督察(督政)和微观督查...     

环渤海高铁沿线可达性及其空间格局演变研究

以环渤海高铁沿线城市为对象,研究高铁通车前后的可达性状况及其空间分异格局,预测未来沿线空间格局的演变态势,结果表明:(1)环渤海高铁的开通大大提升了沿线的可达性,时空收敛效应显著,呈以高铁轴带为核心、轴带外围为边缘的"核心-边缘"格局,高铁轴带内部呈现线路"中间高、首末低"的分异特征,可达性最优要素由京、津向环渤海高铁线路两侧扩散;(2)环渤海高铁沿线城市可达性的提升加速沿线地区空间格局的演变和重塑,表现在环渤海高铁"C"形轴带空间极化程度的进一步加深;沿线的辽中南、京津冀、山东半岛三大城市群一体化进程显现,产生1+1+1＞3的组合效应;环渤海港口群对接铁路线,空间分化与组合日趋复杂;响应"一带一路"倡议,强化与中蒙俄经济走廊战略通道的融合.     

The use of semipermeable membrane devices as passive samplers to determine persistent organic compounds in indoor air

In the study reported here semipermeable membrane devices (SPMDs) were used to sample 28 PAHs and 19 PCBs in the gas phase in 15 single-family houses located in an area where domestic wood burning is widespread. Eight of the households used wood burning appliances whereas the others used other systems for residential heating. Most of the studied compounds were found in the houses: the PAHs at levels that were similar to or slightly higher than published SPMD-sampled levels for background or urban sites in Sweden, and the PCBs at levels that were somewhat lower than those recently found in both indoor and outdoor urban locations. A principal component analysis revealed that wood-burning heating systems may contribute to PAHs in indoor air. The sources may be emissions indoors or penetration from outdoors. The convenience of SPMD technology facilitates its use for semi-quantitative screening and monitoring of various persistent organic compounds indoors in dwellings and working environments.     

过山车立环轨道设计方法

基于加速度研究过山车立环轨道曲线的设计方法.分别研究向心加速度恒定的立环曲线,加速度恒定的立环曲线和以欧拉螺线为基础的立环曲线.建立三种立环曲线的方程,通过数值方法进行求解,借助Matlab计算在给定初始条件和边界条件下的轨道曲线.以加速度为评判标准来分析三种曲线的优点和缺点,最终得到以加速度为基础的立环轨道曲线设计方...     

基于指标气体关联分析的煤自燃分级预警研究

为准确预警煤炭自然发火,基于程序升温试验,获得指标气体与温度间的关系,并将起始温度V0和特征温度点V1、V2、V3时刻的碳氧化物比率作为预警界限,设定4级预警机制,采用灰色关联分析法关联性分析采空区和上隅角CO气体体积分数和碳氧化物比率,按照关联等级的高低细化4级预警机制,同时选取典型案例,详细展示该预警机制下的预警流...