Reconstructed Light Extinction Coefficients Using Chemical Compositions of PM_(2.5) in Winter in Urban Guangzhou, China

The objective of this study was to reconstruct light extinction coefficients （b ext ） according to chemical composition components of particulate matter up to 2.5 μm in size （PM 2.5 ）. PM 2.5 samples were collected at the monitoring station of the South China of Institute of Environmental Science （SCIES, Guangzhou, China） during January 2010, and the online absorbing and scattering coefficients were obtained using an aethalometer and a nephelometer. The measured values of light absorption coefficient by particle （b ap ） and light scattering coefficient by particle （b sp ） significantly correlated （R 2 0.95） with values of b ap and b sp that were reconstructed using the Interagency Monitoring of Protected Visual Environments （IMPROVE） formula when RH was 70%. The measured b ext had a good correlation （R 2 0.83） with the calculated b ext under ambient RH conditions. The result of source apportionment of b ext showed that ammonium sulfate [（NH 4 ） 2 SO 4 ] was the largest contributor （35.0%） to b ext , followed by ammonium nitrate （NH 4 NO 3 , 22.9%）, organic matter （16.1%）, elemental carbon （11.8%）, sea salt （4.7%）, and nitrogen dioxide （NO 2 , 9.6%）. To improve visibility in Guangzhou, the effective control of secondary particles like sulfates, nitrates, and ammonia should be given more attention in urban environmental management.

Study of road tunnel threshold zone lighting reduction coefficient

The luminance in the road tunnel threshold zone attracts broad attention due to its enormous energy consumption and direct influence on tunnel transportation security.Current lighting design methods in threshold zones mostly adopt the reduction coefficient method.However,the determination of reduction coefficient k simply considers tunnel design speed and flow rate,while excluding outside tunnel luminance and threshold zone color temperature and luminance,which have a major impact on driver visual adaptation.Existing problems in the determination of k value are analyzed;a visual performance experiment is utilized;and the reaction time of drivers in changeable outside tunnel luminance and threshold zone color temperature and luminance conditions is obtained;thus,the equations concerning reduction coefficient variation law are derived.In the end,a comparative analysis is made of the k values of the reduction coefficient stipulated by various norms under different color temperature conditions.

Measurement and analysis of ozone, ultraviolet B and aerosol light scattering coefficients in the Arctic

Tropospheric ozone （O3）, ultraviolet B （UVB） radiation and aerosol light scattering coefficients （SC） were investigated on a cruise ship during the fourth Chinese National Arctic Research Expedition from July 1 September 20, 2010. The results showed that O3, UVB and SC decreased with increasing latitude, with minimum values recorded in the central Arctic Ocean. Average O3 concentrations were 15.9 ppbv and 15.1 ppbv in the Bering Sea and Arctic Ocean, respectively. Ozone concentrations increased to 17.5 ppbv in the high Arctic region. Average UVB values were 0.26 W.m-2 and 0.14 W.m-2 in the Bering Sea and Arctic Ocean, respectively. The average SC in the Bering Sea was 4.3 M.m-1, more than twice the value measured in the Arctic Ocean, which had an average value of 1.7 M.m-1. Overall, UVB and SC values were stable in the central Arctic Ocean.

Calculation and application of partition coefficients of light hydrocarbons in oil-based mud system

To find out the relationship between the oil-based mud,the formation fluid and the extracted gas,we use a thermodynamic approach based on static headspace gas chromatography technique to calculate the partition coefficients of 47 kinds of light hydrocarbons compounds between nC5 and nC8 in two kinds of oil-based mud-air systems,and reconstruct the original formation fluid composition under thermodynamic equilibrium.The oil-based drilling mud has little effect on the formation fluid compositions in the range of nC5-nC8(less than 1%for low-toxicity oil-based mud and less than 10%for oil-based mud).For most light hydrocarbon compositions,the partition coefficients obtained by vapor phase calibration and the direct quantitative methods have errors of less than 10%,and the partition coefficients obtained by direct quantitative method are more accurate.The reconstructed compositions of the two kinds of crude oil have match degrees of 91%and 89%with their real compositions,proving the feasibility and accuracy of reconstructing the composition of original formation fluid by using partition coefficients of light hydrocarbon compositions between nC5 and nC8.

Particularities in the Design of Underwater Lighting Systems

The light propagation medium determines the way in which the light is perceived by the observer’s eye.As water is a good transmitter and diffuser,when designing an underwater lighting system there are features in addition to be analyzed,which complement the common considerations for usual artificial lighting systems.The paper aims to present in detail a luminaire calculation method for 4 different types of pools with clear and transparent water(three recreational swimming pools of same size and depth,situated in interior and exterior and one small training interior swimming pool having the size of a quarter of professional competition type).There is a proposed formula for determining the number of floodlights,depending on water surface,immersion depth,average illumination on surface,uniformity,luminous flux of the light source and a water light distribution coefficient.There are highlighted specific variable parameters to be taken into account to meet the visual requirements mentioned in regulations.Depending on the application,visual comfort can be easily disturbed by the changing criteria of ambiance or surroundings,thus diminishing the visual performance.

Optimizing Optical Attocells Positioning of Indoor Visible Light Communication System

Visible light communication(VLC),which is a prominent emerging solution that complements the radio frequency(RF)technology,exhibits the potential to meet the demands of fifth-generation(5G)and beyond technologies.The random movement of mobile terminals in the indoor environment is a challenge in the VLC system.The model of optical attocells has a critical role in the uniform distribution and the quality of communication links in terms of received power and signal-to-noise ratio(SNR).As such,the optical attocells positions were optimized in this study with a developed try and error(TE)algorithm.The optimized optical attocells were examined and compared with previous models.This novel approach had successfully increased minimum received power from−1.29 to−0.225 dBm,along with enhanced SNR performance by 2.06 dB.The bit error rate(BER)was reduced to 4.42×10−8 and 6.63×10−14 by utilizing OOK-NRZ and BPSK modulation techniques,respectively.The optimized attocells positions displayed better uniform distribution,as both received power and SNR performances improved by 0.45 and 0.026,respectively.As the results of the proposed model are optimal,it is suitable for standard office and room model applications.

基于合肥光源数据库的束流寿命分析与诊断

高质量的电子束流寿命数据可以直接反映装置的健康状态,为了获得高质量的束流寿命数据,提出一种束流寿命数据清洗方法,并开展了影响束流寿命的关键因素研究。基于合肥光源历史数据库对2022年以来累积的束流寿命原始数据进行分析,采用Python开发了自动化数据清洗程序,用于获取和处理合肥光源的原始束流寿命数据,以获得长时间跨度的束流寿命变化趋势。通过使用Pearson相关系数对束流寿命异常原因进行分析,发现合肥光源束流寿命受储存环真空压强和高频腔压的影响较大。该束流寿命清洗程序处理快捷,获取的高质量束流寿命数据可以为合肥光源的健康状态检测诊断和预警提供重要依据。

轮轨摩擦系数对低地板轻轨动力响应及车轮磨耗的影响

为了确保低地板轻轨车辆安全且平稳地运行,以某轻轨线路为依托,利用多体动力学软件UM(Universal Mechanism)建立了低地板轻轨车辆-轨道耦合动力学模型。选用LM磨耗型车轮踏面以及R50标准钢轨,以美国六级不平顺轨道谱作为线路激扰。基于Hertz及Kalker简化理论、Archard模型,进行不同摩擦系数共5个工况下车辆动力响应以及车轮磨耗变化规律的仿真分析。在此基础上进一步分析了4个不同运行里程阶段对应共96组车轮磨耗型面下轻轨车辆安全性指标的变化规律。研究了4个不同运行里程阶段对应的不同车轮磨耗型面下车辆过曲线时安全性指标随摩擦系数的变化情况。结果表明:脱轨系数、轮轴横向力、轮轨横向力、车体横向加速度受摩擦系数的影响较为显著,而轮重减载率、车体垂向加速度对摩擦系数的改变并不敏感。车轮磨耗深度随里程和摩擦系数的增加而增大,且相同工况下独立旋转车轮的磨耗情况更加严重。在车辆运行40000 km后,其轮轨横向力、轮轴横向力、脱轨系数整体呈现随里程增加而增大的规律,而轮重减载率基本不受运行里程的影响。在不同摩擦系数及运行里程的叠加影响下,轮轨横向力、轮轴横向力、脱轨系数的峰值出现的位置不同,而轮重减载率却始终处于较为稳定的状态。

刚性挡土墙后轻量土静止土压力特性模型试验研究

为了研究轻量土对挡土结构物的减压机理,通过开展大比尺刚性挡土墙模型试验,采用重物堆载的方式在填土表面施加均布荷载,分析重塑黄土和轻量土作为墙后填土时的静止土压力分布规律。结果表明:轻量土在养护阶段的静止土压力随着时间增长而逐渐增大,但增幅逐渐降低。重塑黄土和轻量土的静止土压力随着填土深度增加近似线性增大,并且静止土压力随着加载而逐渐增大,其中重塑黄土的增幅明显偏大。对比重塑黄土和轻量土的静止土压力,发现轻量土具有明显的减压作用,且填土表面均布荷载越大,轻量土的减压效果越好。重塑黄土和轻量土的静止土压力系数均不是常数,其中重塑黄土静止土压力系数为0.34~0.78,轻量土静止土压力系数为0.22~0.55。当填土表面作用均布荷载时,传统理论在计算重塑黄土静止土压力方面适用性较高,但轻量土计算误差较大。结合模型试验以及传统理论,提出了适用于轻量土的静止土压力修正公式,对比发现其相对误差总体上介于1.01%~23.13%。通过模型试验和理论计算揭示了轻量土的静止土压力特性,对于完善轻量土土压力理论具有重要意义。

基于物理信息神经网络的光波衍射问题求解

用物理信息神经网络方法数值求解间断系数光波衍射问题.结果表明:用光滑函数近似间断系数可大幅度提高物理信息神经网络求解精度;用物理信息神经网络求解散射场比直接求解总场效果更好.最后通过数值实验验证理论结果的正确性.

异色夹纬真丝交织装饰织物的光透射特性

为研究真丝交织装饰织物夹纬颜色对装饰织物透射光的影响,采用多层组织结构试织9种异色夹纬真丝交织织物;借助Digieye数码测色系统和分光光度计,分析在可见光波段内夹纬颜色与织物透射光的关系;通过色温和显色性能研究多层织物中夹纬颜色对光透射特性的影响。结果表明:真丝交织织物遮光率的范围在75.98%~97.72%,织物遮光率会随着夹纬明度的降低而增大;改变夹纬颜色可以有效控制透射光色温的高低,提供不同的冷暖色调;当夹纬的颜色为白色、黑色时,织物透射光的色饱和度与参照照明体相似且显色性能最好,而其他夹纬颜色织物的透射光能够呈现不同的色饱和度与显色性能。研究结果能够为开发具有不同透光率和营造不同居家氛围的装饰织物提供理论参考。

亲水高分子涂层制备过程中水对涂层润滑性能的影响

利用一种通用的两步浸涂+光固化工艺在聚氨酯片材表面制备聚乙烯吡咯烷酮亲水润滑涂层,制备过程中环境湿度(水汽)及涂层溶液含水量对制得涂层的润滑性能会产生一定影响。相较于较低湿度(30%RH)的制备条件,高湿度下(70%RH)制得的涂层其摩擦系数显著下降,平均可从0.183降至0.035。同等湿度下,改变顶层涂层溶液中水的占比,涂层的润滑性能同样呈现出较大差异。在30%RH时,随着顶涂溶液含水量的增加,制得涂层的摩擦系数平均由含水量0wt%时的0.183逐渐降至20wt%时的0.043。当溶剂中水的占比超过一定量时,涂层的润滑性能将向相反方向变化。不同条件下制得涂层的外观形貌以及顶涂溶剂蒸发过程揭示了涂层制备时水对涂层润滑性能的可能影响。

基于Ecotect的科研实验室采光模拟与优化研究——以合肥工业大学数字人居环境研究实验室为例

实验室的采光条件直接影响实验的顺利进行以及实验结果的准确性。该文从采光的形式出发,整理了窗户尺寸、窗地比、玻璃透光率以及遮阳形式等4个室内光环境影响因素,基于Ecotect软件对不同影响因素进行室内光环境模拟分析,通过计算采光系数和采光均匀度定量分析各因素对室内光环境的影响程度,为实验室类建筑改造提供科学依据。

基于LM-LSO算法的磷石膏堆场边坡形态与稳定性智能优化方法

大量欠稳定边坡阻碍了人类工程活动,亟需采用合理的优化方案来确保工程安全。为此,提出了基于列文伯格—马夸尔特(Levenberg-Marquardt,LM)算法和光谱优化算法(Light Spectrum Optimizer,LSO)的边坡形态智能优化方法(LM-LSO)。首先,采用LM算法对样本数据进行非线性拟合;其次,采用拒绝不可行解方法处理稳定性系数的约束问题;最后,利用LSO搜索最优方案,并与另外4种算法进行比较分析。该方法应用于四川省某磷石膏堆场边坡优化,得到了最小挖方量的优化设计方案。该方法综合考虑了边坡优化的经济性和稳定性,保障了堆场的堆填方量和安全。

基于行车安全的隧道照明维养方法研究

为解决因隧道灯具状态变化引起公路隧道路面亮度降低从而导致的行车安全问题,本文通过现场实测与仿真模拟计算灯具衰损路面亮度值,分析路面亮度均匀度对公路隧道照明灯具安全性的影响,对公路隧道灯具划分不同衰损与失效组合,进行现场小目标物视认试验,运用层次分析法与Topsis综合评价模型对试验结果进行分析。结果表明,应针对不同失效组合提出针对性灯具维养方法;当行车安全系数远大于0.52时,可适当降低隧道照明灯具光通量,在保证隧道行车安全的前提下节约能源。

数字普惠金融与经济均衡发展——来自长三角县域夜间灯光的证据

采用夜间灯光数据测算基尼系数反映长三角地区231个区县的经济平衡发展水平,并实证检验数字普惠金融促进区县经济平衡发展的作用与影响机制。结果表明:数字普惠金融能够显著促进长三角地区区县经济平衡发展;机制分析表明,创新驱动和产业结构转型是数字普惠金融促进经济平衡发展的两大重要途径。进一步基于高德地图POI兴趣点的数据分析发现,数字普惠金融能够促使长三角部分业态向落后地区迁移,从而弥合地区差距,促进县域平衡发展。

公路隧道照明中阈限亮度差研究

对比显示系数能够衡量公路隧道照明方式和照明质量,为了得到对比显示系数需要先确定阈限亮度差的取值情况。基于对比显示系数与阈限亮度差之间的关系,采用定值刺激法通过计算机模拟完成阈限亮度差实验。实验分别得到了正负亮度对比、小目标物呈现时间2s情况下不同识别几率时的阈限亮度对比数据,经统计分析得到正负亮度对比下的阈限亮度差数学模型;最后依据观察者年龄、小目标物正负亮度对比和小目标物呈现时间来修正阈限亮度差。

灌溉和干旱及氮素水平对孕穗期冬小麦冠层光分布影响

探讨灌溉和干旱以及氮素对多穗型和大穗型小麦的冠层光分布的影响,为作物生长模型提供参数。通过试验,以氮素3个主处理,灌溉和干旱2个副处理,采用多穗型‘济麦22’和大穗型‘鲁麦21’为试材,使用美国CI-110型冠层分析仪测定孕穗期、开花期和灌浆期的冠层光分布数据。结果显示,不同类型冬小麦,随着生育期推进,MLA呈现先下降,再上升,同一氮素水平,灌溉增加MLA;孕穗期的TCRP值‘鲁麦21’大于‘济麦22’,随着天顶角增加,两个品种不同氮素,灌溉或干旱的TCRP均下降;TCDP在两个品种不同氮素、灌溉或干旱,都呈现先下降,再上升;K值随着天顶角增加都呈上升趋势。施氮和灌溉对冬小麦孕穗期的冠层光分布产生促进作用。灌溉和增加氮肥,可提高孕穗期叶面积指数LAI,增加叶面倾角MLA,在7.5°和22.5°天顶角时,TCRP值小穗型品种呈增加趋势;TCDP在高N、中N和低N时,无论是灌溉还是干旱,TCDP都呈现先下降,再上升趋势;K值随着天顶角的增加,呈现上升趋势。研究表明,大穗型冬小麦品种在生育前期要减少氮肥使用和适度干旱,多穗型冬小麦的氮肥和水分供给应早于大穗型冬小麦品种,这样才有利于冬小麦孕穗期合理的冠层光分布。本研究结论对于黄淮海冬麦区不同类型冬小麦品种肥水科学管理有一定的指导意义。

海洋激光雷达漫射衰减系数反演方法研究

为了解决漫射衰减系数K d的反演依赖于原位测量数据的问题,提出了一种基于Klett和Fernald法反演K d的融合算法。该融合算法以Klett法反演结果为基准,计算出激光雷达比作为Fernald法迭代时的先验信息,再用Fernald法反演出更加精确的水体漫射衰减系数K d;并运用数学解析模型作为融合算法的仿真数据源,解决了实测信号数据量不足的问题,最后基于自研的双频激光雷达系统,利用海试数据对融合算法进行了实验验证。结果表明,融合算法反演得到K d值的均方根误差值为0.74 m-1,精度优于传统的Klett法和Fernald法;所提出的融合算法能够满足近岸浅海水体漫射衰减系数K d反演的收敛和精度要求,且能在没有原位现场环境先验信息的条件下快速计算激光雷达比。该研究对浅海水域的深度测量以及海洋剖面光学参数的测量是有帮助的。

中空玻璃太阳得热系数和可见光透射比计算

太阳得热系数和可见光透射比是评价中空玻璃隔热性能、采光性能的重要指标。JGJ/T 151—2008《建筑门窗玻璃幕墙热工计算规程》中给出了基于太阳辐射照度的太阳得热系数和可见光透射比计算方法,在此基础上提出了基于单片玻璃光热参数的太阳得热系数和可见光透射比计算方法;采用基于单片玻璃光热参数的计算方法、基于太阳辐射照度的计算方法、软件MQMC计算和实测验证对结果进行了对比,证明了基于单片玻璃光热参数的中空玻璃太阳得热系数和可见光透射比计算方法的可靠性。该方法对于中空玻璃光热性能评价、相关工具开发和建筑节能工作的推进具有重要意义。