Effect of Aging on Solar Reflectance of White Cool Roof Coatings:Natural Weathering and the Influence on Building Energy Needs for Different Climate Conditions in Brazil

The use of cool materials on the building envelope is one of the most cost-effective ways to increase indoor thermal comfort conditions in hot climates and decrease the cooling energy needs.Despite the benefit of reducing cooling loads,researches have demonstrated that aging of roof coatings changes the initial solar reflectance(SR),which influences the long term building thermal and energy performance.Thus,this work presents preliminary natural weathering tests performed on samples of nine white coatings exposed to natural weathering for one year in the city of Sao Carlos,Brazil.Solar reflectances were measured with a spectrophotometer before and after exposure,every 3 months,for identifying the effect of aging along the time.The findings showed changes of 13%to 23%on SR after one year of natural weathering,with higher decrease on SR for rougher surfaces.The cleaning process restored from 90%to 100%of the original SR,which means maintenance can be an effective solution to restore the initial SR.Simulations indicated that roofs with higher solar reflectance increase indoor thermal comfort conditions and decrease the cooling energy need for buildings in hot climates,but the aging of white coatings increased the cooling energy needs along the time.

Natural aging mechanism of buried polyethylene pipelines during long-term service

Currently,accelerated aging tests are widely used to study the aging process of polyethylene pipelines.However,this approach can only simulate one or several main influencing factors in the natural environment,which are often quite different from the actual environment of the buried pipelines.In this study,five types of PE80 buried pipelines in service for 9e18 years were taken as the research object,while new PE80 pipelines were taken as the reference group.The aging process and mechanism of polyethylene buried pipelines were studied through mechanical and chemical property tests and microstructural analysis.The results showed that the pipeline exhibited cross-linking as the main aging mechanism after being in service for 0e18 years.The aging degree and law of the inner and outer surface of the pipeline were compared,and the observed mechanism of both surfaces was explained.After 18 years in service,the elongation at the break of the pipe decreased by 16.2%,and the toughness of the matrix in the main collapse area of the tensile sample was the fundamental reason responsible for changes in the mechanical properties.Finally,after 18 years in service,the oxidation induction time of the pipeline was 25.7 min,which was 28.5% higher than the national standard value.There were no potential safety hazards during continuous long-term service.The results of this paper provide reference data and theoretical guidance for the aging process study of buried polyethylene pipelines.

Prototyping low-cost automatic weather stations for natural disaster monitoring

Weather events put human lives at risk mostly when people might occupy areas susceptible to natural disasters.Deploying Professional Weather Stations(PWS)in vulnerable areas is key for monitoring weather with reliable measurements.However,such professional instrumentation is notably expensive while remote sensing from a number of stations is paramount.This imposes challenges on the large-scale weather station deployment for broad monitoring from large observation networks such as in Cemaden—The Brazilian National Center for Monitoring and Early Warning of Natural Disasters.In this context,in this paper,we propose a Low-Cost Automatic Weather Station(LCAWS)system developed from Commercial Off-The-Shelf(COTS)and open-source Internet of Things(IoT)technologies,which provides measurements as reliable as a reference PWS for natural disaster monitoring.When being automatic,LCAWS is a stand-alone photovoltaic system connected wirelessly to the Internet in order to provide real-time reliable end-to-end weather measurements.To achieve data reliability,we propose an intelligent sensor calibration method to correct measures.From a 30-day uninterrupted observation with sampling in minute resolution,we show that the calibrated LCAWS sensors have no statistically significant differences from the PWS measurements.As such,LCAWS has opened opportunities for reducing maintenance costs in Cemaden's observational network.

Combination of atezolizumab and chidamide to maintain long-term remission in refractory metastatic extranodal natural killer/T-cell lymphoma:A case report

BACKGROUND The prognosis of refractory extranodal natural killer/T-cell lymphoma(ENKTL)is poor.Recent data have indicated that immune checkpoint blockade with a programmed cell death protein-1(PD-1)antibody in combination with administration of histone deacetylase inhibitors represents a potentially effective treatment strategy.Compared with PD-1 antibodies,programmed death-ligand 1 antibodies have fewer side effects.Here,we present a rare case of a patient with refractory metastatic ENKTL who achieved sustained remission of approximately 10 mo with minor adverse effects after combination therapy with atezolizumab,chidamide,and radiotherapy.CASE SUMMARY A 56-year-old woman underwent resection of a tumour in her left nasal cavity and was diagnosed with ENKTL(nasal type).Medical examination revealed tumours observed in the bilateral nasal mucosa,the subcutaneous soft tissue of the inner side of the left eye,the soft tissue of the nasopharynx,the bilateral tonsils,and the left preauricular,right hilar,bilateral neck lymph nodes and bone marrow.However,tomography/computed tomography showed increased metabolism of the bilateral nasal mucosa and subcutaneous soft tissue of the inner side of the left eye and newly increased metabolism of the left cervical lymph node after chemotherapy.Therefore,combination therapy with chidamide,atezolizumab,and radiotherapy was performed.Fortunately,the patient achieved a complete response following 10 mo of combination therapy.CONCLUSION The outcome in this case suggests that the combination of atezolizumab,chidamide,and radiotherapy is a promising regimen for treating refractory metastatic ENKTL following chemotherapy treatment failure.

The First Natural Ventilation Assessment in Building Design in Djibouti

With a sustained period of economic growth, rapidly growing populations and with more diversified economies Africa need sustainable development; hence the greater need for massive investments in energy. Sub-Saharan countries such as Djibouti have the potential and ability to harness their natural ventilation as a passive cooling system for designing new houses. The rapid expansion of the Djibouti city is affecting negatively the environment and the safety and comfort of its inhabitants. Proper atmospheric urban planning and management are key to making cities environmentally friendly and sustainable. Based on energy consumption, climate conditions in Djibouti and numerical analysis using Computational Fluid Dynamics （CFD）, it is apparent that the natural ventilation creates a thermally comfortable indoor environment in buildings during the cool season of the year. Measured wind data from two measurement systems are presented and discussed. Statistical analyses, wind rose, Weibull distribution were carried out to understand the natural ventilation characteristic, which is used for evolving the basic criteria for economic viability of building in the semi-arid climate of Djibouti. The study found that it is possible to benefit from natural ventilation in buildings during the cool season of the year.

Automatic Generation of Artificial Space Weather Forecast Product Based on Sequence-to-sequence Model

Both analyzing a large amount of space weather observed data and alleviating personal experience bias are significant challenges in generating artificial space weather forecast products.With the use of natural language generation methods based on the sequence-to-sequence model,space weather forecast texts can be automatically generated.To conduct our generation tasks at a fine-grained level,a taxonomy of space weather phenomena based on descriptions is presented.Then,our MDH(Multi-Domain Hybrid)model is proposed for generating space weather summaries in two stages.This model is composed of three sequence-to-sequence-based deep neural network sub-models(one Bidirectional Auto-Regressive Transformers pre-trained model and two Transformer models).Then,to evaluate how well MDH performs,quality evaluation metrics based on two prevalent automatic metrics and our innovative human metric are presented.The comprehensive scores of the three summaries generating tasks on testing datasets are 70.87,93.50,and 92.69,respectively.The results suggest that MDH can generate space weather summaries with high accuracy and coherence,as well as suitable length,which can assist forecasters in generating high-quality space weather forecast products,despite the data being starved.

气象指数保险下订单农业供应链的政府补贴机制

农业生产遭受自然灾害的威胁且农户面临销售难的困扰,因此各级政府出台了补贴政策促进农业发展并帮助农户增产增收,那么如何选择补贴方式来保证补贴政策的有效性?为此,在气象指数保险下,构建由农户、涉农企业、政府和保险公司组成的订单农业供应链的Stackelberg博弈决策模型,探讨了生产成本补贴与收购价格补贴对供应链各成员的影响.研究表明:与无补贴机制的农户效用对比,政府提供生产成本补贴时反而有可能损害农户的效用,而提供收购价格补贴时农户的效用总是增加.当天气指数较小(较大),即农户所获赔付额较少(较多)时,政府提供收购价格(生产成本)补贴更能提升农户效用和涉农企业收益,且政府提供生产成本补贴更利于提升社会福利.

古生物化石的风化机理与保护研究进展

化石是研究地质历史、气候变迁、生物演化等的实证,有着极其重要的科学价值。一般情况下,化石经过成岩和化石化作用被无机矿物交代,有一定的抗风化能力,在经过常规清理加固处理即可稳定保存。然而在相对潮湿的环境中,部分化石因其组成成分容易发生物理化学变化,从而开裂粉化,严重威胁其保存。笔者等简要回顾了化石修理加固技术的发展历史,并从风化机理和保护两方面着重介绍了当前学界对化石中盐风化、黄铁矿氧化、干燥失水开裂等方面的研究进展,最后简要对化石保护与文物保护的关系进行论述,以期推动化石保护学科的深入发展。

煤矸石集料的加速风化制度研究

本文以三种不同排放地的原状煤矸石为研究对象,分别采用干湿循环、冻融循环以及耐崩解性试验对煤矸石集料进行加速风化,旨在研究煤矸石的风化特性。以加速风化后的煤矸石集料质量损失率和压碎值指标对煤矸石风化特性进行表征,研究加速风化制度、颗粒粒径、服役状态对煤矸石集料风化特性的影响,同时采用XRD、SEM以及EDS微观测试手段揭示煤矸石的风化机理。结果表明:采用干湿循环方式得到的煤矸石集料质量损失率和压碎值指标与自然状态下煤矸石集料风化180 d的最为接近,同时煤矸石集料粒径越大越容易发生风化,且服役状态下,煤矸石集料的风化作用不明显。微观测试结果表明,煤矸石风化机理为在风化过程中煤矸石内部的矿物组成及结构受到破坏,导致煤矸石发生崩解、脱落,而服役状态下的煤矸石由于被胶凝材料包裹,风化概率有效减小。

华北唐宋古瓷窑兴起的自然条件:煤系地层出露

为探究华北唐宋著名古瓷窑兴起的自然条件及其实质,收集了54个华北唐宋著名古瓷窑址,综合煤田地质学、地理学和考古学等展开探讨。空间分析揭示这些古瓷窑址均坐落在石炭纪—二叠纪煤系地层边缘出露区,整体呈现“东密西疏”的分布格局。煤系地层出露不仅暴露了煤而且暴露了煤的共伴生矿产——煤系高岭岩;此煤系高岭岩经历百万年级的自然暴露,在空气和水的持续作用下发生了地球化学风化作用,逐渐形成含水凝胶态的高龄泥。研究显示,煤系地层天然出露为泛华北唐宋古瓷窑兴起提供了自然条件,实质是利用天然可塑性的高龄泥直接制胎。

汽车零部件金属卤素灯阳光模拟试验与户外自然曝晒的相关性研究

目的 探究汽车零部件金属卤素灯阳光模拟加速试验与户外自然曝晒的关系。方法 使用3种典型高分子透明材料分别进行阳光模拟加速试验、AIMBOX/Arizona户外曝晒和Florida户外曝晒,基于试验后样品的黄变值,比较阳光模拟试验与户外曝晒的相关性,并对阳光模拟试验与户外曝晒的加速性进行探讨。结果 阳光模拟(IP/DP箱)加速试验与AIM BOX/Arizona户外曝晒高度相关,综合加速倍率约是AIM BOX/Arizona户外曝晒的3倍。阳光模拟(IP/DP箱外)加速试验与Florida户外曝晒高度相关,综合加速倍率是Florida户外曝晒的7倍。结论 基于3种典型材料研究可知,汽车零部件阳光模拟加速试验与典型户外自然曝晒具有一定相关性。

The dynamic development of bacterial community following long-term weathering of bauxite residue

Bauxite residue is the industrial waste generated from alumina production and commonly deposited in impoundments.These sites are bare of vegetation due to the extreme high salinity and alkalinity,as well as lack of nutrients.However,long term weathering processes could improve residue properties to support the plant establishment.Here we investigate the development of bacterial communities and the geochemical drivers in bauxite residue,using Illumina high-throughput sequencing technology.Long term weathering reduced the pH in bauxite residue and increased its nutrients content.The bacterial community also significantly developed during long term weathering processes.Taxonomic analysis revealed that natural weathering processes encouraged the populations of Proteobacteria,Chloroflexi,Acidobacteria and Planctomycetes,whereas reducing the populations of Firmicutes and Actinobacteria.Redundancy analysis(RDA)indicated that total organic carbon(TOC)was the dominant factors affecting microbial structure.The results have demonstrated that natural weathering processes improved the soil development on the abandoned bauxite residue disposal areas,which also increased our understanding of the correlation between microbial variation and residue properties during natural weathering processes in Bauxite residue disposal areas.

Comparison of surface water chemistry and weathering effects of two lake basins in the Changtang Nature Reserve,China

The geochemistry of natural waters in the Changtang Nature Reserve,northern Tibet,can help us understand the geology of catchments,and provide additional insight in surface processes that influence water chemistry such as rock weathering on the Qinghai–Tibet Plateau.However,severe natural conditions are responsible for a lack of scientific data for this area.This study represents the first investigation of the chemical composition of surface waters and weathering effects in two lake basins in the reserve（Lake Dogaicoring Qiangco and Lake Longwei Co）.The results indicate that total dissolved solids（TDS）in the two lakes are significantly higher than in other gauged lakes on the Qinghai–Tibet Plateau,reaching 20–40 g/L,and that TDS of the tectonic lake（Lake Dogaicoring Qiangco）is significantly higher than that of the barrier lake（Lake Longwei Co）.Na＋and Cl-are the dominant ions in the lake waters as well as in the glacier-fed lake inflows,with chemical compositions mainly affected by halite weathering.In contrast,ion contents of inflowing rivers fed by nearby runoff are lower and concentrations of dominant ions are not significant.Evaporite,silicate,and carbonate weathering has relatively equal effects on these rivers.Due to their limited scope,small streams near the lakes are less affected by carbonate than by silicate weathering.

基于RASA的智能气象问答服务技术的设计研究

本研究基于Rasa开源问答系统框架和Flask轻量级Web服务框架,设计面向任务的智能气象问答系统。文章重点介绍了Rasa框架的关键模块RasaNLU,并结合自然语言理解中的意图和命名实体,设计了对话追踪和对话策略优化,相较于Rasa框架自带的RasaCore,在响应速度上得到了提升,同时详细描述了智能问答在气象可视化上的应用。

装配式建筑用硅烷改性聚醚密封胶的耐候性能研究

以硅烷改性聚醚为基础聚合物,添加复配光稳定剂(UV-326+UV-770),制备了一种耐候性能优异的单组分室温固化密封胶。通过自然曝晒和紫外加速老化试验研究发现,复配光稳定剂在提高密封胶耐候性方面优于单一光稳定剂。当光稳定剂添加量未达饱和时,密封胶的耐候性随添加量增加而提升;超过饱和点后,继续增加用量则不再显著改善耐候性,并可能导致其他性能下降及成本增加。

双层熔结粉末涂料的制备及其在天然气管道上的涂装应用

采用环氧粉末涂料作为底涂层,聚酯粉末涂料作为面涂层,研究双层熔结粉末在天然气管道上分别喷涂后一次成膜的性能。底涂层以自制的熔结环氧粉末为主要成膜物,面涂层以聚酯为主要成膜物,探讨了聚酯粉末配方组成、胶化时间、固化时间等的影响因素及双涂层施工工艺对性能的影响。制备了既具有防腐性能又具有较高耐候性能的天然气管道用复合涂层,解决了长期以来城市天然气管道仅用熔结环氧粉末涂装时存在的耐候性问题。

厚质建筑涂料保色耐污性能常用测试方法比较

由于厚质建筑涂料应用广泛,所以对其涂层耐气候老化后的保色耐污性能要求高。本研究采用自然气候曝晒试验、人工加速老化试验、耐沾污性试验、耐雨水污痕试验和户外涂装墙试验5种方法对两种厚质建筑涂料(多彩涂料和真石漆)进行检测,考察其保色、耐污性能,并对5种测试方法的结果进行了比较,为厚质涂料的应用提供了有益参考。

干、湿热自然气候环境下塑料老化——PP老化规律研究

选取具显著特点的干、湿热自然环境条件的新疆吐鲁番和广州两处地点,进行自然老化试验。探讨了耐候聚丙烯(PP)材料在干、湿热不同的自然环境中,其外观变化、力学性能变化的老化规律性。实验表明:耐候PP材料2年期内在干、温热两种不同自然气候环境中力学性能的老化行为规律基本相同,下降趋势一致,自然气候环境中湿度对PP材料影响不明显。

PBO纤维自然老化与加速老化的相关性研究

研究了PBO纤维在户外自然暴晒实验中纤维强度和分子量的变化规律,发现PBO纤维在暴晒初期纤维强度下降较快,但随着老化时间的延长,纤维强度下降趋势逐渐变缓。此外,文章还对比研究了人工加速老化过程中纤维强度的下降规律,并以强度保持率为参照标准,分别从老化时间和总辐照能量两方面比较了2种老化实验的相关性和加速因子。研究发现,基于老化时间作为参照时,在老化的不同阶段,加速因子的变化较大;而基于总辐照能量作为参照时,在纤维强度降低到原始强度的64%之前,可较好地利用人工加速老化实验结果来预测其在户外环境下的老化失效行为。