An agent-based model of red colobus resources and disease dynamics implicates key resource sites as hot spots of disease transmission

The effect of anthropogenic landscape change on disease in wildlife populations represents a growing conservation and public health concern. Red colobus monkeys (Procolobus rufomitratus), an endangered primate species, are particularly susceptible to habitat alteration and have been the focus of a great deal of disease and ecological research as a result. To infer how landscape changes can affect host and parasite dynamics, a spatially explicit agent-based model is created to simulate movement and foraging of this primate, based on a resource landscape estimated from extensive plot-derived tree population data from Kibale National Park, Uganda. Changes to this resource landscape are used to simulate effects of anthropogenic forest change. With each change in the landscape, disease outcomes within the simulated red colobus population are monitored using a hypothetical microparasite with a directly transmitted life cycle. The model predicts an optimal distribution of resources which facilitates the spread of an infectious agent through the simulated population. The density of resource rich sites and the overall heterogeneity of the landscape are important factors contributing to this spread. The characteristics of this optimal distribution are similar to those of logged sections of forest adjacent to our study area.     

Simulation of thermodynamic transmission in green roof ecosystem

Green roofs entail the creation of vegetated space on the top of artificial structures. They can modify the thermal properties of buildings to bring cooling energy conservation and improve human comfort. This study evaluates the thermodynamic transmission in the green roof ecosystem under different vegetation treatments. Our model simulation is based on the traditional Bowen ratio energy balance model (BREBM) and a proposed solar radiation shield effectiveness model (SEM). The BREBM investigates energy absorption of different components of radiation, and the SEM evaluates the radiation shield effects. The proposed model is tested and validated to be efficient to simulate solar energy transmission in green roofs, with some major findings. Firstly, the solar radiation transmission processes might be considered as free vibration motion. Daytime positive heat storage of the green roof is 350-520 W·m⁻² on an hourly basis. Nighttime or afternoon negative value registers a rather constant magnitude of −60 W·m⁻². Daily net average is positive around 155-210 W·m⁻². Secondly, solar radiation vibration is highly correlated with plant structure. The canopy reflectance and transmittance are strongly correlated (R² = 0.87). The multi-layer shrub treatment has the highest shield effectiveness (0.34), followed by two-layer groundcover (0.27), and single-layer grass (0.16). Green roof vegetation absorbs and stores large amounts of heat to form an effective thermal buffer against daily temperature fluctuation. Vegetated roofs drastically depress air temperature in comparison with bare ground (control treatment). Finally, the thermodynamic model is relatively simple and efficient for investigating thermodynamic transmission in green roof ecosystem, and it could be developed into a broad solar radiant land cover model.     

烟花爆竹燃放对四川盆地边缘城市环境空气的影响及其污染传输特征研究

为了解四川盆地边缘城市环境空气质量受烟花爆竹燃放影响的特征,选取位于成都平原西南部的乐山市进行研究。研究发现,春节期间乐山市受烟花爆竹燃放影响的环境空气中的颗粒物及其组分的浓度变化趋势一致。相关性分析结果显示：在除夕夜烟花爆竹燃放影响时间段内,乐山市环境空气中的颗粒物(PM₁₀、PM_2.5)浓度与SO₄^2-、F^-、Al、K、Mn、Cu、Zn等组分浓度呈显著正相关,Pearson相关系数达到了0.48～0.73;Al、Si、K、Mn、Cu、Zn等组分浓度之间也表现出显著正相关,Pearson相关系数高达0.78～0.98。其中,K⁺浓度占比从0%上升到7.32%,SO₄^2-浓度占比从18.94%上升到24.73%,Cl^-浓度占比从0.46%上升到4.29%,Cu元素浓度占比从0.05%上升到0.30%,Al元素浓度占比从5.87%上升到7.46%。除夕夜烟花爆竹燃放影响期间,乐山市中部和北部区...     

天然气气田开发中钻井与集输管线工程环境监理浅议

天然气气田开发工程属生态影响类建设项目,其中以钻井工程和集输管线工程对环境影响最大,其特点是：污染物种类复杂,环境影响时间长,影响范围广,生态扰动大。本文结合某大型天然气气田开发工程环境监理的工作实践,归纳总结了钻井工程和集输管线工程的特点,并针对工程实施过程中存在的主要环境问题,着重分析了开展工程环境监理的重点工作内容。     

“特色交通标志”设计及其信息量度量方法研究

为提高道路交通标志准确适时的信息传递功能,在对交通标志信息传递原理进行分析的基础上,对"特色交通标志"的设计及交通标志承载的信息量量化方法进行深入研究。基于以人为本的思想,提出便于用路者辨识的"特色交通标志"设计理念,并以青藏公路为例,设计具有西藏地域特色的人性化交通标志。将视觉选择性原理引入到传统信息传递过程中,建立特色交通标志信息传递的理论模型。结合信息论中信息度量方法,提出交通标志信息量数学量化方法,并将普通交通标志与"特色交通标志"的信息量进行对比。结果表明:"特色交通标志"信息量往往较大,但在不超过标志承载最大信息量286.3 bit的前提下,"特色交通标志"信息传递性更强,更易使人们接受。     

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,...     

中国清洁电力发展对二氧化碳排放的空间效应及影响路径研究

有关清洁电力是否有效降低二氧化碳排放,有两种不同观点,本文分析了产生争议的原因,并基于机理分析,选取1998—2018年中国30个省份的相关数据,利用空间面板杜宾模型研究清洁电力发展对区域二氧化碳排放的影响。回归结果显示：(1)二氧化碳排放在省域之间具有显著的正向空间溢出效应。(2)清洁电力发展与二氧化碳排放之间呈倒U形关系并通过了一系列稳健性检验。(3)进一步地通过效应分解发现,清洁电力发展无论是直接效应还是间接效应,均需要达到一定的门槛值之后才会对区域二氧化碳排放产生促减效用。最后,通过中介效应模型检验发现,清洁电力发展带来的能源消费结构调整和能源利用效率改变是影响二氧化碳排放的作用机制。     

遗传禁忌搜索的能量均衡深井安全监测WSN分簇路由算法

针对深井巷道无线传感器网络（Wireless Sensor Networks,WSN）安全监测中节点能量消耗不均匀导致网络生命周期较短的问题,在分析低功耗自适应集簇分层型算法（Low Energy Adaptive Clustering Hierarchy,LEACH）、遗传算法（Genetic Algorithm,GA）和禁忌搜索算法（Tabu Search Algorithm,TS）的基础上,提出遗传禁忌搜索的能量均衡深井安全监测WSN分簇路由算法（GTSR-EB）,以分簇方式来减少数据发送量与寻优开销,利用优化GA算法和TS算法进行多路径搜索以选出一条能耗均衡、路径传输距离最短的最优路径。仿真实验表明:GTSR-EB算法网络存活周期为LEACH算法的2.17倍、GA算法的1.18倍,GTSR-EB网络能量利用率更高、生存周期更长。     

Silica nanoparticles and silver-doped silica nanoparticles induce endoplasmatic reticulum stress response and alter cytochrome P4501A activity

Engineered silica nanoparticles (SiO₂-NPs) find widespread application and may lead to exposure of humans and the environment. Here we compare the effects of SiO₂-NPs and SiO₂-NPs doped with silver (SiO₂-Ag-NPs) on survival and cellular function of human liver cells (Huh7) and Pimephales promelas (fathead minnow) fibroblast cells (FMH). In Huh7 cells we investigate effects on the endoplasmatic reticulum (ER), including ER stress, and interactions of nanoparticles (NPs) with metabolizing enzymes and efflux transporters. The NPs formed agglomerates/aggregates in cell culture media as revealed by SEM and TEM. SiO₂ and SiO₂-1% Ag-NPs were taken up into cells as demonstrated by agglomerates occurring in vesicular-like structures or freely dispersed in the cytosol. Cytotoxicity was more pronounced in Huh7 than in FMH cells, and increased with silver content in silver-doped NPs. Dissolved silver was the most significant factor for cytotoxicity. At toxic and non-cytotoxic concentrations SiO₂-NPs and SiO₂-1% Ag-NPs induced perturbations in the function of ER. In Huh7 cells NPs induced the unfolded protein response (UPR), or ER stress response, as demonstrated in induced expression of BiP and splicing of XBP1 mRNA, two selective markers of ER stress. Additionally, SiO₂-1% Ag-NPs and AgNO₃ induced reactive oxygen species. Pre-treatment of Huh7 cells with SiO₂-1% Ag-NPs followed by exposure to the inducer benzo(a)pyrene caused a significant reduced induction of CYP1A activity. NPs did not alter the activity of ABC transporters. These data demonstrate for the first time that SiO₂-NPs and SiO₂-1% Ag-NPs result in perturbations of the ER leading to the ER stress response. This represents a novel and significant cellular signalling pathway contributing to the cytotoxicity of NPs.     

固体声在建筑物内的衰减、反射和透射

固体声波在建筑物内传播会产生衰减、反射和透射。文中对居民楼内的固体传声进行了理论分析,认为建筑物内固体声传播过程中存在扩散衰减、结构突变衰减和阻尼损失衰减。同时,固体声波在墙体或楼板内反射使声能密度大大增加;固体声在传播过程中会向空气中透射,使得居民室内产生结构噪声污染。文中对某小区变压器房结构噪声进行理论分析和计算,预测了变压器房上方室内的结构噪声级,计算结果表明,当设备基础上振动级达到90 dB时,二楼居民室内的结构噪声级可达到41.3 dB,这对人们的正常生活会产生十分不利的影响。计算值与实际测量值较为吻合,说明理论分析和预测计算基本是可信的。