机场周边环境噪声验收监测频次探究

通过比较3个不同类型机场周边敏感点噪声连续1昼夜、连续2昼夜与连续7昼夜平均计权等效连续感觉声级值之间的差异发现,对于同一监测目标,连续1昼夜与连续7昼夜声级值差异不超过2.2 d B,连续2昼夜与连续7昼夜声级值差异不超过1.8 d B,连续1昼夜或2昼夜与连续7昼夜的噪声监测结果差别不大。     

我国职业噪声危害成因分析及总体控制对策

职业噪声不仅属于职业卫生问题 ,也是当今世界上主要的环境公害之一。有效控制职业噪声不仅能够保护劳动者的听力不受损害 ,使其身心安全与健康得到保障 ,同时也是消除安全隐患 ,实现安全生产的重要途径。笔者分析了我国职业噪声危害的现状 ,论述了我国职业噪声危害的严重性以及控制的重要性与迫切性。然后采用“人 -机 -环境”系统工程方法 ,分别从人的行为、物的状态以及工作环境等 3个方面 ,分析职业噪声危害的成因 ,构造了基于宏观管理维、中观人机环境维以及微观技术维等三维结构的我国职业噪声危害控制总体框架 ,并从政府、企业以及劳动者等角度 ,对职业噪声危害控制的运行机制进行了研究 ,以解决我国日益严重的职业噪声危害问题 ,不断改善我国安全生产现状并进一步提高劳动保护工作的整体水平。     

社会噪声污染对环境影响分析

社会噪声主要指营业性文化娱乐活动和商业经营活动中使用的设备、设施产生的噪声。本文主要从目前存在的社会噪声的各个方面论述居民受噪声污染的主要因素,并针对存在的问题提出整治措施和合理化的建议,使人们远离噪声污染。     

伊宁市“一五”期间环境质量噪声变化分析及措施

根据伊宁市“十一五”期间环境噪声质量监测结果,分析了环境噪声的变化趋势,总结了经验,提出进一步提高环境质量的措施。     

城区快速路交通噪声测试与防治对策

采用现场调查的方法对沈阳市某快速路交通噪声状况进行测试,根据现场调查测试结果分析:噪声强度在快速路两侧高层建筑物的高度分布不同,其随距建筑物横向距离的增大呈衰减特性,其随时间的变化幅度较小,进而对快速路两侧敏感建筑物的噪声防治提出相应对策。     

Species-specific tuning increases robustness to sampling bias in models of species distributions: An implementation with Maxent

Various methods exist to model a species’ niche and geographic distribution using environmental data for the study region and occurrence localities documenting the species’ presence (typically from museums and herbaria). In presence-only modelling, geographic sampling bias and small sample sizes represent challenges for many species. Overfitting to the bias and/or noise characteristic of such datasets can seriously compromise model generality and transferability, which are critical to many current applications - including studies of invasive species, the effects of climatic change, and niche evolution. Even when transferability is not necessary, applications to many areas, including conservation biology, macroecology, and zoonotic diseases, require models that are not overfit. We evaluated these issues using a maximum entropy approach (Maxent) for the shrew Cryptotis meridensis, which is endemic to the Cordillera de Mérida in Venezuela. To simulate strong sampling bias, we divided localities into two datasets: those from a portion of the species’ range that has seen high sampling effort (for model calibration) and those from other areas of the species’ range, where less sampling has occurred (for model evaluation). Before modelling, we assessed the climatic values of localities in the two datasets to determine whether any environmental bias accompanies the geographic bias. Then, to identify optimal levels of model complexity (and minimize overfitting), we made models and tuned model settings, comparing performance with that achieved using default settings. We randomly selected localities for model calibration (sets of 5, 10, 15, and 20 localities) and varied the level of model complexity considered (linear versus both linear and quadratic features) and two aspects of the strength of protection against overfitting (regularization). Environmental bias indeed corresponded to the geographic bias between datasets, with differences in median and observed range (minima and/or maxima) for some variables. Model performance varied greatly according to the level of regularization. Intermediate regularization consistently led to the best models, with decreased performance at low and generally at high regularization. Optimal levels of regularization differed between sample-size-dependent and sample-size-independent approaches, but both reached similar levels of maximal performance. In several cases, the optimal regularization value was different from (usually higher than) the default one. Models calibrated with both linear and quadratic features outperformed those made with just linear features. Results were remarkably consistent across the examined sample sizes. Models made with few and biased localities achieved high predictive ability when appropriate regularization was employed and optimal model complexity was identified. Species-specific tuning of model settings can have great benefits over the use of default settings.     

浅谈噪声防治

本文主要论述噪声对环境的影响和对人体的危害，从而提出对噪声的防治方法。     

武汉工业大学水泵房噪声治理

分析了水泵房噪声产生的机理,提出以隔声为主,辅以消声、吸声、绿化等综合治理措施,实现了治理达标目的。     

木工机械的噪声及控制

针对木工机械在工作过程中产生的噪声进行测试、分类，并提出控制措施及方法．