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831.
通过对气候变暖和沈阳城市的发展造成沈阳城市热岛增强并加重大气污染的现状分析,提出通过增加绿化面积等措施,可将沈阳的灰霾日数控制在每年60d左右,还能够降低城市温度,增加空气湿度,提高人体舒适度并促进经济发展。  相似文献   
832.
    
Urban lakes confront significant threats due to changes in land use and land cover (LULC) resulting from urbanization and subsequent climate change. This review discusses the intricate effects of the urban heat island phenomenon on lakes, specifically attributed to LULC changes. Utilizing the Scopus and Web of Science databases, this study gathers the most pertinent earlier research in the LULC and water bodies. This study systematically categorizes variables into five distinct groups and scrutinizes the drivers, parameters, tools, and management strategies influencing the LULC dynamics on lakes. A research gap is identified in understanding the conjoined impacts of LULC and urban heat island effects within urban lake environments. The review further investigates diverse ways in which LULC impacts lakes, intersecting with multiple United Nations sustainable development goals (SDGs), notably SDGs 6, 11, 13, and 15. Consequently, this review serves as a valuable contribution to the understanding of LULC to provide substantial benefits to the urban climate research toward meeting SDGs.  相似文献   
833.
This study was carried out in one of the medium-sized public administrative towns in the southwestern part of Nigeria. Its aim is to highlight the effect of spatial distribution of settlements, population, and socio-economic activities on urban air temperature and humidity in the town. Temperature and relative humidity data from 1992 to 2001 were obtained from three meteorological stations in Akure, the Administrative Capital of Ondo State, Nigeria. The stations are located within the Federal Ministry of Aviation, Akure Airport (FMA), Federal University of Technology, Akure (FUTA) and Federal School of Agriculture (SOA). Air temperature and relative humidity measurements were also obtained from 27 points, which were cited to include road junctions, markets, built up areas, etc., using sling psychrometer. The data were subsequently analysed for spatial and temporal variations using statistical packages (SPSS and Microsoft Excel) and isolines. Actual vapour pressure and dew point temperature were computed using Magnus conversion formulae. The results obtained showed that spatial variation was insignificant, in terms of the temperature and humidity variables. The annual mean temperature (Tmean) ranged between 21.9 and 30.4 degrees C while minimum (Tmin) and maximum (Tmax) temperatures varied from 13 to 26 and 21.5-39.6 degrees C, respectively. Relative humidity (RH), actual vapour pressure (Es) and dew point temperature (Td) values also varied from 39.1% to 98.2%, 19.7-20.8 gm(-3), and 17.3-17.8 degrees C, respectively. A significant relationship (p>0.6; r<0.05) between Tmin, Es and Td was observed while the daytime 'urban heat island' intensity (UHI) ranged between 0.5 and 2.5 degrees C within the study period. The study concluded that there is influence of urban canopy on the microclimate of Akure, and hypothesizes that the urban dwellers may be subjected to some levels of weather related physiological disorderliness.  相似文献   
834.
城市污泥既是污染物又是一种资源,污泥的处理、处置与资源化利用相结合才是其最好的出路。概述了堆肥、碱性稳定化、热干化、焚烧等几种主要的污泥处理和利用方案,并简述了在污泥利用方案选择时需考虑的因素。  相似文献   
835.
    
ABSTRACT

In this study, the combined thermodynamic and dynamic model of a new concept of gamma type free-piston Stirling engine is conducted. The engine consists of two identical displacer cylinders, a power cylinder, a linear alternator, and three-cushion pistons. Two displacer cylinders are symmetrically positioned on each side of the power cylinder for minimizing the rotational vibrations. Hydrogen is used as the working gas and the effect of gas temperature on the specific heat capacity is considered. The analysis carried out in this study involves the prediction of the thermodynamic-dynamic performance characteristics of the engine. In the thermodynamic section of the analysis, the working space of the engine is divided into 31 nodal volumes and the gas pressures in nodal volumes are assumed to be equal to each other. The conservation of mass and energy equations is obtained for each nodal volume. Instantaneous gas temperatures of nodal volumes are calculated by the first law of thermodynamics given for the unsteady open systems. The dynamic section of the analysis involves the motion equations of displacer, power and cushion pistons. The motion equations are derived using the Newton method. In the calculations done for variable specific heat capacity, it has been determined that there is 1% cyclic work reduction compared to the constant heat capacity. It is estimated that the maximum effective power that can be produced by the linear alternator will be around 1.6 kW. The working frequency range of the proposed engine is found to be suitable to generate electrical power.  相似文献   
836.
ABSTRACT: Evaporative heat loss is an essential component of any heat budget used for the modeling of lake water temperatures. Seven evaporative heat loss equations were tested in a year-round, physically-based temperature and dissolved oxygen model for lakes. Deciding which equation to choose for use in the year-round model was based on the goodness of fit of the simulated vs. measured surface temperatures, which were taken at a depth of 1 m below the water surface. An equation which includes free and forced convection components and which was previously used for cooling ponds gave the best fit between temperature simulations and measurements.  相似文献   
837.
研究太阳辐射、地表面辐射平衡与热量平衡对深入研究气候形成、地表能量转换、生态系统结构特性以及资源开发保护与国土整治等均具有重要意义。本文根据四川省内近200个台站30年整编的气候资料,并结合自然地理景观选用多种计算公式进行对比,然后采用统一的方法对全省热量平衡各分量逐月进行了计算和分析其时空分布特征。  相似文献   
838.
    
The device performance of double-pass V-corrugated solar air heaters with external recycle was investigated experimentally and theoretically. The comparison between V-corrugated and flat-plate collectors was made to show the thermal efficiency improvement with various operating parameters. The results show that the collector efficiency improvement of the recycling double-pass V-corrugated operation is much higher than those of the other configurations under various recycle ratios and mass flow rates. However, there exists the penalty on the power consumption increment due to implementing V-corrugated channel into the solar air heaters, an economic consideration on both the heat-transfer efficiency enhancement and power consumption increment for the double-pass V-corrugated device was also delineated. The experimental setup was carried out to validate the theoretical predictions, and the fairly good agreement between both results was achieved with the error analysis of 0.48-1.83%.  相似文献   
839.
    
Deploying heating technologies, such as air-source heat pumps (ASHPs), can respond to the dual challenges of tackling fuel poverty and reducing carbon emissions from domestic energy consumption. In the UK, ASHP performance has been found to be below design levels. Elements of three strands of literature – innovation diffusion, environmental psychology and neighbourhood effects – are combined to gain insights into why the adoption and performance of ASHPs are lagging policy targets and design potential. Evidence from users, installers and area-based scheme facilitators suggests that the perceived complexity of the technology is a barrier. The level of technology maturity and the typical profile of the elderly fuel poor do not match; the target group might prefer to be late adopters or laggards in adopting technology. The role of installers is critical as the disruption from installation is a barrier to adoption and ASHPs place demands on users to change existing practices.  相似文献   
840.
Structures may be exposed to fire and blast due to accidents (i.e. explosion of flammable gas in industrial structures) or terrorist attacks during the service life. Performances of RC structures subjected to extreme conditions of fire and blast, thus, have drawn much attention from academia. In this paper, the coupling effect of high temperature and high strain rate in concrete was firstly studied based on the experimental data to improve the damage plasticity concrete model in ABAQUS. Secondly, the transient heat transfer effects in different fire scenarios and following fire resistances of RC columns with constant axial forces were numerically investigated on the basis of the improved concrete model, which are validated by the corresponding test data, and the residual axial loading capacity of RC columns was quantitatively calculated. By incorporating the different merits of implicit algorithm applied to heat transfer analyses and explicit algorithm usually used in blast analyses, a numerical approach to analyze the responses of RC columns subjected to the coupling loadings of fire and blast was finally developed. Mid-span displacements and damage of the RC columns subjected to fire and explosions were quantitatively calculated and discussed. The proposed approach was demonstrated to be effective in predicting the responses of RC structures subjected to coupling loadings of fire and blast.  相似文献   
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