一种基于支持向量机回归的旋转遮光带日射表散射辐照度修正新算法

通过比较旋转遮光带日射表(RSP)和参考标准表所测散射辐照度之间的数值差异,分析了太阳总辐照度、环境温度、相对湿度和太阳光谱等气象要素对RSP散射辐照度测量误差的影响关系,提出了一种修正RSP散射辐照度测量值的新算法。该算法从支持向量机回归预测角度,建立了对RSP散射误差修正值的一次预测模型,然后根据误差修正值最优预测模型推导出RSP散射辐照度修正算法模型。利用该算法对美国国家太阳辐射研究实验室和劳里观测站采集的RSP散射辐照度数据进行修正,修正后两观测站数据的平均偏差和均方根误差分别降低到-0.2W/m2,3.3W/m2和1.9W/m2,8.5W/m2,显示算法具有良好的修正性能和适用性。该算法能够有效避免Vignola算法中存在的欠修正和Vignola and Augustyn(VA)算法中存在的过修正现象。     

偏最小二乘回归在微波效应预测中的应用

 引入偏最小二乘回归(PLSR)原理和方法应用于微波效应实验数据的预测,得到的预测精度与自适应神经模糊推理网络(ANFIS)结果基本一致,平均相对误差小于3%。实例分析了PLSR方法与ANFIS方法对建模数据样本量的需求,在建模样本数较少条件下,PLSR所建模型的预测精度均高于ANFIS模型。因此PLSR方法更适用于微波效应小样本数据的预测,更有利于实际应用。     

Modeling of Thermal Conductivity of Concrete with Vermiculite by Using Artificial Neural Networks Approaches

In this article, the thermal conductivity of concrete with vermiculite is determined and also predicted by using artificial neural networks approaches, namely the radial basis neural network and multi-layer perceptron. In these models, 20 datasets were used. For the training set, 12 datasets (60%) were randomly selected, and the residual datasets (8 datasets, 40%) were selected as the test set. The root mean square error, the mean absolute error, and determination coefficient statistics are used as evaluation criteria of the models, and the experimental results are compared with these models. It is found that the radial basis neural network model is superior to the other models.     

自动寻日的太阳辐照绝对辐射计

为了准确测量太阳总量辐射,研制了具备自动跟踪能力的太阳辐照绝对辐射计SIAR-3a.介绍了SIAR-3a的原理,提出了双轴太阳跟踪的控制方法.SIAR-3a采用电来标定待测量的太阳总量辐射,可以在测量太阳总量辐射的同时较为准确地跟踪太阳.标定实验中,SIAR-3a在3σ范围内的相对均方根误差是0.06%,已经标定到了保...     

太阳能聚焦光斑能流密度测量方法评估

为了确定一种新型间接测量太阳能热发电系统聚焦光斑能流密度分布方法的测量误差范围,对其进行了进一步研究。从理论公式出发,分析了该测量方法的误差源;使用球面小定日镜、CCD相机、漫反射板、中性密度滤光片等设备进行了能流密度测量的实验,使用MATLAB软件对实验数据进行处理,得到了漫反射板上聚焦光斑的能流密度分布和总能量;实验时借助全站仪测量并计算了定日镜中心的光线入射角,根据定日镜的面积和反射率、太阳直射辐射值、余弦效率等计算了光斑能量的理论值,并与测量得到的聚焦光斑总能量比较,得出了实验条件下该方法测量光斑总能量以及能流密度的相对误差为3.5%。该测量误差在允许范围内,进一步证实了该能流密度测量方法的正确性和可行性。     

实用型三谱段太阳模拟器的设计与研制

本文设计并研制了一种实用型三谱段太阳模拟器,其光谱匹配可同时调整3个谱段(300~700 nm,700~900 nm,900~1 700 nm)范围的能量,修正后可满足三结砷化镓太阳电池的测试使用要求。本文重点阐述了三谱段太阳模拟器滤光片的设计和氙灯光谱的修正及测试,介绍了太阳模拟器的光机结构。实验表明:三谱段太阳模拟器的光谱匹配满足三结砷化镓太阳电池各子电池的响应电流值。在有效辐照面150 mm×150 mm上,平均辐照度可以达到2个太阳常数(2 730 W/m²),辐照不均匀度达到±1.77%,辐照不稳定度达到±0.83%,为太阳电池自动分拣系统提供了可靠稳定的平台。     

中低温太阳能品位间接提升及系统集成

本文提出了中低温太阳热能品位间接提升的概念、方法和系统集成,其核心是热集成和热化学转换的有机结合。在所提出的太阳能和化石能源综合互补的化学回热循环系统(SOLRGT)中,中低温太阳热能首先提供蒸汽蒸发潜热从而转化为蒸汽内能;其次通过蒸汽参与重整反应进一步转化为合成气化学能,实现品位提升;最后得以在高效的燃气轮机系统中实现热功转换。由于太阳能的引入,燃气轮机透平排气余热回收部分的热匹配得到极大改善,并减少了化石能源消耗;同时,蒸汽产率的增加有助于增进系统化学回热和物理回热收益。系统中太阳能热转功净效率可达26.5%;和常规化学回热循环相比,化石能源节约率可达20%～30%,实现相应数量的CO_2减排,系统中实现了中低温太阳能的高效热功转换和与化石燃料的梯级互补。     

槽式聚光光伏-光热化学互补系统中吸热反应管性能研究

本文以槽式聚光光伏-光热化学互补系统为对象,并以甲醇裂解反应为例,探究了该系统内的吸热反应管在入射光谱仅为透过的红外光谱波段时的性能。研究结果表明,当几何聚光比为21.4时,透射到吸热反应管的红外光谱能量转化为太阳能燃料化学能的效率可达54%~58%。此外,还研究了太阳直射辐射强度、甲醇进口流量、甲醇进口温度等关键运行参数对吸热反应管中反应管温度、甲醇转化率等的影响。本文的研究工作为探索聚光光伏-光热化学互补方法提供了一种可能。     

太阳辐射的在轨监测和定标

采用宽视场设计,逐轨扫描太阳式测量方式的FY-3A太阳辐射监测仪,结合在轨一年半的太阳辐照度观测数据和地面实验与理论分析,研究了影响定标精度的因素,给出了修正方程和曲线,并通过与世界辐射基准(WRR)的地面外场定标实验,得到了FY-3A上的三台绝对辐射计的比例系数R1=1.008 3,R2=1.006 6和R3=1.006 5。日地距离的理论分析和实际太阳辐照度测量曲线均证明:地球近日点太阳辐照度值最大,远日点太阳辐照度值最小,且在±3.34%范围内随日期变化。利用天文公式,结合遥感源包中的准确测量时间,给出了日、地修正系数。另外,分析了冷空间背景辐射对定标精度的影响,给出了冷空间辐射值的计算公式,并结合宽视场设计和扫描式测量的特点,重点分析了采光结束时刻和刚捕获太阳光时刻入射角的差异给辐照度测量带来的影响,通过几何关系给出了入射角修正系数方程及修正曲线。最后,综合各定标修正系数,给出了在轨定标方程和定标曲线,并分析了定标精度。     

Reply to the Comment of G. Feulner

In my reply I present a re-analysis of the data of the Smithsonian Astrophysical Observatory (SAO). For this, a new data reduction method is introduced, allowing a drastic lowering of data scatter, so that the time series of the reduced data clearly shows the ≈ 1% variation of the terrestric solar irradiance in parallel with solar activity. The implications are discussed.     

星载太阳紫外光谱监视器的地面辐射定标

星载太阳紫外光谱监视器是一种小型化、高精度紫外-真空紫外光谱辐射计,它有两种工作模式,即探测太阳紫外光谱辐照度的太阳模式和探测大气的太阳后向散射紫外光谱辐亮度的大气模式。对应这两种工作模式分别建立了紫外-真空紫外光谱辐照度和紫外光谱辐亮度定标装置。光谱辐照度标准灯直接辐照仪器的漫反射板进行仪器的光谱辐照度响应度定标,光谱辐照度标准灯辐照标准漫反射板形成朗伯面光源进行仪器的光谱辐亮度响应度定标。误差分析表明:160~250 nm光谱辐照度绝对定标误差为6.5%,250~400 nm为4.3%;250~400 nm光谱辐亮度绝对定标误差为5.9%。星载太阳紫外光谱监视器获得的地外太阳紫外光谱辐照度与大气的太阳后向散射光谱辐亮度数据,同国际上的观测结果相比一致性达±10%。     

可见-近红外波段太阳光谱辐照度仪的辐射定标方法研究

为了满足可见-近红外波段太阳光谱的高精度观测需求,对使用细分光谱技术进行太阳直射辐射观测的新型太阳光谱辐照度仪,开展了辐射定标方法的研究。使用光谱辐照度标准灯在400 nm～1 050 nm光谱范围内对仪器进行相对定标,对满足比尔-朗伯定理的波段采用Langley法进行绝对定标,在整个光谱范围内将辐射基准溯源到大气层顶的太阳光谱辐照度。在甘肃敦煌和安徽合肥两地进行了室外比对实验,仪器观测结果和MODTRAN4.0模型的理论模拟结果一致,和CE318的4个气溶胶观测通道的结果偏差在5%以内,验证了该定标方法的合理性。     

中低温太阳能-甲醇重整互补供能系统动力学提升与系统优化

本文考察了中低温-甲醇重整互补制氢及其与高温质子交换膜燃料电池(HT-PEMFC)结合的中低温太阳能-甲醇重整互补发电系统,并分析、优化了两供能系统的性能。从动力学性能优化角度,研发了一种适用于甲醇重整制氢反应的新型复合金属氧化物纳米催化剂,并测试了不同反应物体积流量与反应温度下的催化剂性能。基于动力学实验结果,模拟了太阳能-甲醇重整互补供能系统的性能。模拟结果显示,在太阳直射辐照强度为1000 W·m^-2、反应物体积流量为1.70 mL·min^-1时,采用新型纳米催化剂的互补制氢系统太阳能制氢效率与能量利用总效率分别为52.5%与87.5%,比采用铜锌铝商业催化剂的系统提高了12.4个百分点和3.3个百分点。如将重整产物气用于高温质子交换膜燃料电池发电,则太阳直射辐照强度为10000 W·m^-2、反应物体积流量为1.75 mL·min^-1时,中低温太阳能-甲醇重整互补发电系统太阳能净发电效率(40.9%)比应用商业催化剂的系统提高10.4个百分点。     

太阳能热气流电站系统研究

由于现有模型不足以准确描述太阳能热气流发电系统的物理机制,本文提出一个更完善的数学模型去分析太阳能热气流电站系统的相对压力分布和系统抽力．模型中考虑了太阳辐射和系统尺寸参数对系统相对压力和系统抽力的影响。以西班牙试验电站为例进行数值模拟,探索系统尺寸参数和太阳辐射对系统相对压力和系统抽力的影响。数值计算结果与理论分析具有良好的一致性．     

Impact of aerosols on the forecast accuracy of solar irradiance calculated by a numerical weather prediction model

The impact of aerosols on the forecast accuracy of solar irradiance calculated by a fine-scale, one day-ahead, and operational numerical weather prediction model (NWP) is investigated in this study. In order to investigate the impact of aerosols only, the clear sky period is chosen, which is defined as when there are no clouds in the observation data and in the forecast data at the same time. The evaluation of the forecast accuracy of the solar irradiance is done at a single observation point that is sometimes affected by aerosol events. The analysis period is one year from April 2010 to March 2011. During the clear sky period, the root mean square errors (RMSE) of the global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance (DHI) are 40.0?W?m^?2, 84.0?Wm^?2, and 47.9?W?m^?2, respectively. During one extreme event, the RMSEs of the GHI, DNI, and DHI are 70.1?W?m^?2, 211.6?W?m^?2, and 141.7?W?m^?2, respectively. It is revealed that the extreme events were caused by aerosols such as dust or haze. In order to investigate the impact of the aerosols, the sensitivity experiments of the aerosol optical depth (AOD) for the extreme events are executed. The best result is obtained by changing the AOD to 2.5 times the original AOD. This changed AOD is consistent with the satellite observation. Thus, it is our conclusion that an accurate aerosol forecast is important for the forecast accuracy of the solar irradiance.     

Training Multilayer Perceptron with Genetic Algorithms and Particle Swarm Optimization for Modeling Stock Price Index Prediction

Predicting stock market (SM) trends is an issue of great interest among researchers, investors and traders since the successful prediction of SMs’ direction may promise various benefits. Because of the fairly nonlinear nature of the historical data, accurate estimation of the SM direction is a rather challenging issue. The aim of this study is to present a novel machine learning (ML) model to forecast the movement of the Borsa Istanbul (BIST) 100 index. Modeling was performed by multilayer perceptron–genetic algorithms (MLP–GA) and multilayer perceptron–particle swarm optimization (MLP–PSO) in two scenarios considering Tanh (x) and the default Gaussian function as the output function. The historical financial time series data utilized in this research is from 1996 to 2020, consisting of nine technical indicators. Results are assessed using Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE) and correlation coefficient values to compare the accuracy and performance of the developed models. Based on the results, the involvement of the Tanh (x) as the output function, improved the accuracy of models compared with the default Gaussian function, significantly. MLP–PSO with population size 125, followed by MLP–GA with population size 50, provided higher accuracy for testing, reporting RMSE of 0.732583 and 0.733063, MAPE of 28.16%, 29.09% and correlation coefficient of 0.694 and 0.695, respectively. According to the results, using the hybrid ML method could successfully improve the prediction accuracy.     

Nanocomposites: Synthesis,characterization and its application to removal azo dyes using ultrasonic assisted method: Modeling and optimization

S-doped and Cu- and Co-doped TiO₂ was synthesized by a sol–gel method and characterized by FE-SEM, XRD, EDX and FTIR. The Co/Cu/S-TiO₂ nanocomposite loaded on the activated carbon as new nanoadsorbent was used for simultaneous removal of methylene blue (MB) and sunset yellow (SY) from aqueous solution by ultrasonic-assisted adsorption method. In this work, central composite design (CCD) and adaptive neuro-fuzzy inference system (ANFIS) as a support tool for examining data and making prediction are used to recognize and predict the removal percentage in MB and SY dye solution of different concentrations. The predictive capabilities of CCD and ANFIS are compared in terms of square correlation coefficient (R²), root mean square error (RMSE), mean absolute error (MAE) and absolute average deviation (AAD) against the empirical data. It is found that the ANFIS model shows the better prediction accuracy than the CCD model.In addition to, the optimization of ultrasound-assisted simultaneous removal of methylene blue (MB) and sunset yellow (SY) on the Co/Cu/S-TiO₂/AC nanocomposite by response surface methodology (RSM) for the optimization of the process variables, such as MB and SY concentrations, Co/Cu/S-TiO₂/AC nanocomposite dose and sonication time, was investigated.Various isotherm and kinetic models were used in the experimental data. The results revealed that the langmuir isotherm and pseudo-second-order model had a better correlation than the other models.     

大面积准直型太阳模拟器的设计与研制

设计并研制了一种大面积准直型太阳模拟器,其有效辐照面直径达到1 100 mm,平均辐照度达到1.3个太阳常数（AM0）,光束准直角为±1.59°。首先给出了太阳模拟器的光学系统,分别从光源选择和布局,椭球镜设计和准直镜设计进行了阐述;介绍了太阳模拟器的光机结构;进行了系统的仿真和实现。实验表明,太阳模拟器的平均辐照度达到1 760 W/m²,辐照不均匀度达到±4.6%,辐照体不均匀度达到±5.96%,辐照不稳定度达到±1.36%,光谱匹配在300~1 400 nm波长范围内满足ASTM E927-10中AM0 B级要求,为航天有效载荷的热真空试验和热平衡试验提供了一个准确可靠的平台。