压力对镜质组反射率与烃类生成的影响

镜质组反射率是广泛使用的成熟度参数 ,长期以来人们普遍认为温度和时间是控制镜质组反射率的主要因素 ,而压力对反射率的影响人们知之甚少。本文综述了模拟实验和地质实例中压力对镜质组反射率和烃类生成影响的不同观点。介绍了过压造成镜质组反射率延尺的两个动力学模型     

Effects of soiling and cleaning on the reflectance and solar heat gain of a light-colored roofing membrane

A roof with high solar reflectance and high thermal emittance (e.g., a white roof) stays cool in the sun, reducing cooling power demand in a conditioned building and increasing summertime comfort in an unconditioned building. The high initial solar reflectance of a white membrane roof (circa 0.8) can be lowered by deposition of soot, dust, and/or biomass (e.g., fungi or algae) to about 0.6; degraded solar reflectances range from 0.3 to 0.8, depending on exposure. We investigate the effects of soiling and cleaning on the solar spectral reflectances and solar absorptances of 15 initially white or light-gray polyvinyl chloride membrane samples taken from roofs across the United States. Black carbon and organic carbon were the two identifiable strongly absorbing contaminants on the membranes. Wiping was effective at removing black carbon, and less so at removing organic carbon. Rinsing and/or washing removed nearly all of the remaining soil layer, with the exception of (a) thin layers of organic carbon and (b) isolated dark spots of biomass. Bleach was required to clear these last two features. At the most soiled location on each membrane, the ratio of solar reflectance to unsoiled solar reflectance (a measure of cleanliness) ranged from 0.41 to 0.89 for the soiled samples; 0.53 to 0.95 for the wiped samples; 0.74 to 0.98 for the rinsed samples; 0.79 to 1.00 for the washed samples; and 0.94 to 1.02 for the bleached samples. However, the influences of membrane soiling and cleaning on roof heat gain are better gauged by fractional variations in solar absorptance. Solar absorptance ratios (indicating solar heat gain relative to that of an unsoiled membrane) ranged from 1.4 to 3.5 for the soiled samples; 1.1 to 3.1 for the wiped samples; 1.0 to 2.0 for the rinsed samples; 1.0 to 1.9 for the washed samples; and 0.9 to 1.3 for the bleached samples.     

SeaWiFS资料水色辐射模式验证的研究

从１９９４ 年～１９９７ 年，作者对杭州湾与长江口海区、台湾至吕宋以东海区和渤海海区，进行了多次光谱测量和同步取样试验，将试验所得资料经计算机处理，确定了三种验证区域各种水色要素与遥感光谱值之间的关系，提出适用于我国验证区域各种水色的验证模式。其各水色模式验证偏差均小于２０％ ，并适用于我国海域ＳｅａＷｉＦＳ水色遥感应用。     

大气红外辐射超高光谱探测仪临边探测—污染气体的反演精度和光谱通道评估

利用RFM模式,模拟计算了在研仪器—大气红外辐射超高光谱探测仪的临边探测模式下大气污染气体体积混合比的权重函数.结合仪器的可探测亮温阈值（0.3 K）,利用权重函数线性化方法,计算并分析了6种大气状态下,气体混合比廓线在不同反演精度条件下可获得的光谱通道数随切点高度的变化,并给出了可用光谱通道在不同切点高度的位置.结果表明,随着相对反演精度的降低,可用光谱通道数量增加,除热带大气外,其它5种大气在10%臭氧反演精度和5%甲烷反演精度条件下有足够的通道,可用于反演4.6 km以上的混合比廓线.CO在15%反演精度条件下,6种大气均能获得反演6.9 km以上廓线的光谱通道.近地面切点高度反演比较困难,很难获得较高的反演精度.可用光谱通道位置与气体吸收线位置特别是峰值区域一致,也与气体模拟亮温高值区一致.     

太湖有色可溶性有机物组成结构对不同水文情景的响应

有色可溶性有机物(CDOM)是溶解性有机物中能强烈吸收紫外辐射及蓝光的那部分有机物,并在碳、氮、磷等生源要素生物地球化学循环中起着重要的作用.开展富营养化湖泊CDOM来源、组成结构和空间变化趋势的相关研究,有利于更好地揭示湖泊生源要素循环机制,服务于蓝藻水华控制和湖泊水质改善.本文基于对不同水文情景下太湖和周边连通的51条河流CDOM光谱吸收及三维荧光光谱测定与分析,揭示太湖CDOM光谱组成对不同水文情景的响应机制.结果表明,丰水期溶解有机碳浓度均值(8. 11±1. 26) mg·L~(-1),显著大于枯水期均值(3. 53±1. 19) mg·L~(-1)(t-test,P 0. 01),而丰水期CDOM吸收光谱斜率S_(275～295)均值(19. 09±1. 81)μm~(-1),显著小于枯水期的(20. 89±1. 90)μm~(-1)(t-test,P 0. 001).平行因子分析法对CDOM荧光图谱进行解析得到3个组分,且各组分受到上游来水量的影响较大,丰水期陆源类腐殖酸的荧光强度及占总荧光强度比重较枯水期显著增大.叶绿素a与化学需氧量与陆源腐殖质和类色氨酸均呈显著正相关(P 0. 01),这表明陆源生活污水及藻死亡降解产生的CDOM可能是太湖CDOM库的重要潜在来源.溶解氧浓度与3种荧光组成均呈现显著负相关(P 0. 01),说明CDOM不同组分均为微生物活动的重要基质.本研究结果还发现溶解性有机碳浓度与陆源类腐殖酸组分荧光强度呈极显著线性正相关(r~2=0. 58,P 0. 001),表明太湖溶解性有机碳主要以外源输入为主.     

土壤冻融对溶解性有机质与菲结合的影响

以沈阳市公园土壤和道路边土壤中的溶解性有机质(DOM)为研究对象,利用荧光淬灭法测定DOM与菲的结合常数(K),考察了冷冻温度、融化温度、冷冻时间和冻融次数对其光谱学特性及其与菲的结合常数(K)的影响,并结合相关性矩阵分析K与其他参数的关系.结果表明:冻融处理条件下,K值与溶解性有机碳含量(DOC)显著负相关(p0.01),与254 nm处的紫外吸光系数(a_(254))和单位浓度DOC的254 nm的紫外吸光值(SUVA)显著正相关(p0.01).城市公园土壤DOM和城市道路边土壤DOM的K值都是3.5×10~4L·kg~(-1),经过冷冻温度、冷冻时间和冻融次数相同的冻融处理后,城市公园土壤DOM的K值始终高于城市道路边土壤DOM,这是由于冻融导致城市土壤DOM的芳香性高于城市道路边土壤DOM,而分子量小于城市道路边土壤DOM.经过冻融作用二者的K值变化范围分别为1.6×10~5～8.4×10~5L·kg~(-1)和1.5×10~5～3.7×10~5L·kg~(-1),冻融作用使二者的K值都增大一个数量级.这一方面会增强固相土壤中多环芳烃的溶出和迁移,另一方面也会降低多环芳烃的生物可利用性.     

Evaluating the blue-light hazard from solid state lighting

Purpose. New light sources including light-emitting diodes (LEDs) have elicited questions about retinal damage, including the blue-light hazard. Some organizations have recommended avoiding using LEDs with correlated color temperatures exceeding 3000?K, since they tend to produce greater short-wavelength energy. This article provides quantitative comparisons among light sources and use cases as they affect the blue-light hazard. Methods. The spectral radiant power characteristics of incandescent, fluorescent, LED and daylight sources were evaluated in terms of blue-light hazard using standard procedures for phakic, aphakic and pseudophakic eyes. Results. Under most use cases, LEDs do not exhibit greater risk for the blue-light hazard than other sources (e.g., incandescent). Because they generally produce little to no ultraviolet energy, LEDs often present less risk to aphakic eyes. Conclusions. LEDs present no special concerns for the blue-light hazard over some other common sources in typical use cases because photophobic responses limit exposure to bright sources. Where photophobic responses might not occur (e.g., eye surgery patients or premature infants) or where individuals suppress these responses (e.g., stage actors), caution is necessary. Evidence remains inconsistent regarding the risk of human retinal damage from long-term exposures to light insufficient to reach acute blue-light hazard thresholds.     

Advanced treatment of municipal wastewater by nanofiltration: Operational optimization and membrane fouling analysis

Municipal sewage from an oxidation ditch was treated for reuse by nanofiltration (NF) in this study. The NF performance was optimized, and its fouling characteristics after different operational durations (i.e., 48 and 169 hr) were analyzed to investigate the applicability of nanofiltration for water reuse. The optimum performance was achieved when transmembrane pressure = 12 bar, pH = 4 and flow rate = 8 L/min using a GE membrane. The permeate water quality could satisfy the requirements of water reclamation for different uses and local standards for water reuse in Beijing. Flux decline in the fouling experiments could be divided into a rapid flux decline and a quasi-steady state. The boundary flux theory was used to predict the evolution of permeate flux. The expected operational duration based on the 169-hr experiment was 392.6 hr which is 175% longer than that of the 48-hr one. High molecular weight (MW) protein-like substances were suggested to be the dominant foulants after an extended period based on the MW distribution and the fluorescence characteristics. The analyses of infrared spectra and extracellular polymeric substances revealed that the roles of both humic- and polysaccharide-like substances were diminished, while that of protein-like substances were strengthened in the contribution of membrane fouling with time prolonged. Inorganic salts were found to have marginally influence on membrane fouling. Additionally, alkali washing was more efficient at removing organic foulants in the long term, and a combination of water flushing and alkali washing was appropriate for NF fouling control in municipal sewage treatment.     

基于水面反射率光谱分类的太湖藻蓝蛋白浓度反演

藻蓝蛋白是蓝藻的标志性色素,利用遥感反演藻蓝蛋白浓度的时空分布对于蓝藻水华监测和预警具有重要意义.太湖水体光学特性时空差异较大,传统的藻蓝蛋白遥感反演方法在太湖各湖区各季节的适用性有限.因此,本文采用先分类再反演的策略,基于水面反射率光谱分类进行太湖藻蓝蛋白浓度反演建模.首先采用逐步迭代的K均值聚类方法实现光谱分类;然后分别利用每一类的训练样本光谱数据建立最适用于该类的藻蓝蛋白反演模型;最后利用每一类的检验样本光谱数据进行反演模型精度评价.为了对比,同时采用不分类的传统方法进行反演建模和精度评价.检验结果表明:基于不分类的传统建模方法得到的均方根误差RMSE=14.14μg·L-1,平均相对误差σ=59.1%,反演结果和实测数据可决系数为0.46;基于光谱分类的建模方法得到RMSE=8.47μg·L-1,σ=31.3%,反演结果和实测数据可决系数为0.87.因此,基于光谱分类的藻类蛋白反演方法有效地提高了反演精度,可以为其它水体的藻蓝蛋白浓度反演提供借鉴.     

A multiscale hierarchical Markov transition matrix model for generating and analyzing thematic raster maps

A model is described for generating hierarchically scaled spatial pattern as represented in a thematic raster map. The model involves a series of Markov transition matrices, one for each level in the scaling hierarchy. In full generality, the model allows the transition matrices to be different at each level, potentially making available a large number of parameters for landscape characterization. The model is self-similar when the transition matrices are all equal. A method is presented for fitting the model to data that take the form of a single-resolution thematic raster map. Explicit analytic solutions are obtained for the fitted parameters. The fitting method is based on a relationship between the hierarchical transitions in the model and spatial transitions at varying distance scales in the data map, a categorical analogy of the geostatistical variogram.