课程文献中心 更多>>

关键词： 空气污染   环境保护   自然环境   废水废气   环保   小事做起   新风尚   保护环境  

摘要： 亲爱的同学们:大家好!2025年1月,我们将迎来“环境保护月”,主题是“节约新风尚,环保我先行”。保护环境不仅是每个人的责任,更是我们共同的义务。优美的自然环境能给人们带来愉悦的心情,而破坏环境将影响我们的健康和生活。近年来,因滥伐林木、废水废气排放等问题,导致水土流失、空气污染等环境危机。因此,为了拥有清新的空气、湛蓝的天空,我们应从自身做起,从身边小事做起,为环保尽一份力。

关键词： 全自动石墨消解   原子荧光   地球化学样品   回收率   精密度  

摘要： 建立了以全自动石墨消解技术作为样品消解前处理,采用双通道原子荧光光谱仪,测定地球化学样品中的砷、锑、铋、汞的方法流程。确定了微波消解程序及原子荧光仪器工作条件,并按建立的方法对10组地球化学国家标准物质进行测试,分析结果显示,10件国家标准物质的测定回收率分别为As∶96.43%~104.42%,Sb∶94.67%~105.26%,Bi∶95.24%~105.26%,Hg∶92.86%~112%;精密度分别为As∶2.3%~4.88%,Sb∶3.21%~6.38%,Bi∶2.37%~7.57%,Hg∶3.28%~11.13%。该方法应用于多金属地球化学样品的测定,并与电热板溶样法进行了比较。结果表明,该方法对地球化学样品测定效果良好,准确度和精密度符合要求。

关键词： 暖通空调   噪声   振动   防治措施  

摘要： 在建筑暖通空调领域,合理地进行降噪与减振环节的设计不仅有助于减少暖通空调系统运行时的噪声和振动,还能保护周围环境和其他设备免受噪声影响。文章首先对建筑暖通空调系统的特点进行了介绍,强调了其在维持室内舒适度方面的重要性;其次对噪声和振动问题的影响进行了阐述,并提出了相应的降噪与减振防治措施,为建筑暖通空调系统的设计提供优化思路。

关键词： Industrial air pollution   Climate-oriented production system   Environmental monitoring   Machine learning   Artificial neural network   Forecast   Predictive model   IoT   Lagrangian dispersion  

摘要： The paper is devoted to solving the problem, associated with increasing the forecasting accuracy of pollutant concentration level based on PM25 dust. The LANN model (LANN - Lagrange powered Artificial Neuron Network), proposed in the paper, allows you to take into account the mutual influence of pollution sources on the concentration level at monitoring points, which, on the one hand, allows to manage the volume of emissions from industrial enterprises in such away as to avoid penalties and, on the other hand, allows the regulatory agencies to determine points for environmental control, at which permissible standards will be most likely exceeded. The suggested solution makes it possible to use low-cost IoT-based air quality monitoring devices, which were primarily considered not applicable due to their low accuracy and exposure to the influence of short-term stochastic factors;besides, no models were available, which would be capable to provide the necessary accuracy and forecast horizon on the base of IoT data. At the same time, the obtained model has low requirements for computing resources compared to dispersion models and is dependent on the accuracy of weather information;besides, the model allows you to take into account trends and obtain better forecast values in terms of accuracy than the models, that use regression methods, neural network models and ML models, stochastic models and their ensembles. The application of the model improves well-known pollutant dispersion estimation calculation techniques through the use of measurement data flow and dynamic adaptation to changing conditions. The model was trained on the dataset over the period 2022-2023 collected from 5 monitoring devices, which were installed in the catchment area of the group, incl. 13 industrial points of PM25 pollutant sources.

关键词： 农村  

ISBN: (纸本)9787109326101

摘要： 本书针对我国农村人居环境底数不清、风险不明、观测技术不规范、观测标准体系不健全等问题，围绕农村人居环境污染、农村人居环境质量以及农村居民发展长期因子观测，重点阐述了农村人居环境观测标准及质控体系建设、农村人居环境污染因子、农村人居环境质量因子观测目标、原则、内容、方法、质控、数据分析和专题报告等方面，并针对典型案例进行实证分析，提出我国农村人居环境观测的对策与建议，为我国农村人居环境观测提供理论和实践支撑。

关键词： 背景噪声  

ISBN: (纸本)9787562559344

摘要： 本书重点介绍了在城镇环境中如何利用人文背景噪声 (通常是超短的和线性的) 未提取精确的面波信息方法, 以期达到准确刻画浅层速度结构的目的。通过详细介绍高频背景噪声面波方法的理论基础、方法技术和实际案例, 我希望能帮助读者更好地理解这些方法的原理和潜力。

关键词： Bypass ratio  

摘要： The influences of the three-stream introduction and the tertiary bypass ratio on the flow and noise characteristics of the three-stream nozzle were studied by the numerical simulation method. The results showed that the three-stream introduction increased the length of the bypass potential core, shortened the axial distance of the direct mixing between the end of the primary potential core and the free stream, and reduced the peak value of the turbulent mixing between them by about 2.63%. However, due to the increase of the shear layer thickness, the low-speed three-stream had limited noise reduction effect in all directions. The increase of the tertiary bypass ratio was easy to achieve, at the cost of reducing fuel consumption, and it can increase the engine thrust and reduce the broadband noise of the exhaust system. The increase of tertiary bypass ratio to 2.52 weakened not only the turbulent mixing intensity at the end of the primary potential core, but also the mixing intensity of the strong shear layer between the three-stream and the free stream. Compared with the design condition, the mixing intensity at the end of the primary potential core decreased by 8.57%, and the overall sound pressure level decreased in all directions, with a peak value of about 2.37 dB. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.

摘要： 本产品具有国内行业中质量检验的权威性 长期、周到的售后服务让客户无后顾之忧 松香色度标准装置(又名《松香颜色分级标准》玻璃比色块),是符合我国松香光学特性具有完整体系的松香颜色分级标准.1982年荣获林业部科技成果二等奖.1987年至今,被《脂松香》、《松香试验方法》国家标准所采用,并多次经国家质量监督检验检疫总局复查考核合格.

摘要： 项目结合水利工程大中型泵站特点,测量与总结了在建水利工程大中型泵站声环境的实际效果,建立了泵站声环境声场模型,解构与模拟了水泵机组声源;将"声景学"关键技术合理运用至泵站声环境规划中;进行了各类型声源的选择性噪声控制关键技术研究,提出了采用噪声频谱分析技术合理确定降噪措施的方法.

摘要： 党的二十届三中全会提出,中国式现代化是人与自然和谐共生的现代化.必须完善生态文明制度体系,协同推进降碳、减污、扩绿、增长,积极应对气候变化,加快完善落实绿水青山就是金山银山理念的体制机制.