合肥地区2013年春节期间PM2.5质量浓度演变特征

利用2013年2月8~19日合肥地区获取的大气颗粒物和常规气象观测资料,依据烟花爆竹燃放、降水过程、相对湿度和风速特点,分析了PM2.5质量浓度在不同气象条件下的变化特征。结果表明:合肥春节期间PM2.5质量浓度平均值为58.3μg/m~3,仅出现两个PM2.5质量浓度污染日;城市居民集中燃放烟花爆竹引起PM2.5质量浓度急剧增大,但主要排放PM1;降水过程对PM2.5质量浓度具有湿沉降作用,过程降水量越大,PM2.5质量浓度湿沉降量越大;PM1、PM1~2.5和PM2.5~10与相对湿度的相关系数分别为0.45、0.26和-0.07,粒径尺度越小的颗粒物吸湿增长特性越显著;PM2.5质量浓度演变与风速呈负相关,两者的相关系数为-0.33,风速越大,越利于颗粒物扩散。     

包头城区冬春大气颗粒物污染特征及其与气象条件关系

包头2015~2016年冬春季节出现了连续的雾霾天气,不仅对能见度产生较大影响而且严重危害人体健康。选取了包头主城区8个空气质量浓度监测点的数据,对主城区的PM2.5和PM10污染特征进行分析,确定其空间差异特征和时间性变化特征。依据监测区功能的不同将包头主城区划分为5个区域,对各个区域监测点数据筛选整理,得到冬春季各个区域PM2.5和PM10质量浓度由高到低的顺序均为：工业区＞ 商业区 ＞文化区 ＞交通枢纽区＞公园游览区。各区域颗粒物月变化曲线呈双峰单谷型,12月最高,2月最低,并对成因进行分析总结;逐日变化反映PM2.5和PM10质量浓度具有较好的相关性,且受气象条件影响显著;日变化呈双峰双谷趋势。本文选取了气温、气压、相对湿度和风速等气象因子,利用Spearman秩相关分析研究各个气象因子对大气PM2.5和PM10质量浓度的影响。包头春季PM2.5和PM 10的质量浓度分别与气温、气压正相关,与风速、相对湿度（伴有降水时）负相关,风速、气压和相对湿度是影响污染物质量浓度分布的主要因素。     

成都市PM2.5、PM10变化特征及其与气象因素的关系

为研究气象因素对成都市大气细颗粒物 (PM2.5)、可吸入颗粒物 (PM10) 的影响, 收集了2015―2018 年成都市 PM2.5、PM10的月平均浓度, 采用Pearson 相关分析法, 分析了成都市PM2.5、PM10与气象条件的关系。结果表明： (1) 2015 ―2018 年, 成都市PM2.5、PM10年平均浓度虽然年际间差别较小, 但整体呈现逐年缓慢下降趋势, 2015 年以来成都市的 一系列大气污染控制措施是PM2.5、PM10逐年缓慢下降的原因; 2015―2018 年成都市PM2.5、PM10浓度季节变化特征整体 表现为冬季 > 春季 > 秋季> 夏季。(2) 不同气象因素对成都市PM2.5、PM10月平均浓度的影响程度不同, 降水量与气温 是影响成都市PM2.5、PM10月平均浓度的主要因素, 两者与PM2.5、PM10呈较高的负线性相关, 其中PM2.5、PM10与降水量 的相关系数均为 −0.612, 与月平均气温的相关系数分别为 −0.822、−0.776, 降水会通过捕获大气中的颗粒物来去除 PM2.5、PM10, 而温度的升高会加强PM2.5、PM10等污染物在垂直方向上的对流运动, 从而对成都市污染物浓度的降低起 到重要作用; 日照时数、月平均风速、相对湿度等与PM2.5、PM10月平均浓度整体也呈现负相关, 但与降水量和气温相 比, 日照时数、月平均风速与PM2.5、PM10月平均浓度的相关性较低, 而相对湿度与PM2.5、PM10月平均浓度的相关性则 更加微弱, 表明相对湿度的变化对成都市PM2.5、PM10的积累和扩散影响很小。     

静电模块对颗粒物与微生物的净化特性

为了检测空气净化器内静电模块在不同风速、不同湿度下对不同粒径颗粒物以及微生物去除效果,从而对其除尘性能影响因素的分析提供基础性的数据。研究测试了静电模块对PM 0.3、PM 1.0、PM 2.5、PM 10微细粉尘的净化特性及除菌效果。结果表明:在一定范围内,风速越大,则颗粒物衰减越快,当风速为0.5m/s时,衰减速率达到最大,再加大风速,颗粒物衰减的速率下降;当湿度越大时,颗粒物PM 0.3、PM 1.0、PM 2.5、PM 10去除效果下降,相同湿度时,颗粒物粒径越大,越容易去除。风速越高,静电模块除菌的效果越好。风速为0.1m/s时,90 min后,除菌率最终为94.06%,当风速为0.3 m/s、0.5 m/s、0.8 m/s时,除菌率最终可以达到99%。     

气象条件对大气中PM2.5浓度的影响

分析了浙江某地近年1月至9月逐日平均PM2.5浓度与降雨量、温度、湿度和风速等气象参数的关系,得出PM2.5浓度大小与风速的变化密切相关,降雨能降低空气中的PM2.5浓度,在隔离降雨因素的前提下,无论是相对湿度还是绝对湿度与PM2.5浓度都不具有明显的相关性,日平均温度与PM2.5浓度呈现负相关。     

基于激光雷达和地面监测数据对南京一次沙尘和细粒子污染时空演变特征的分析

利用偏振激光雷达对南京2015年3月一次沙尘和细粒子污染共存过程的颗粒物垂直分布特征进行观测研究,结合地面气象数据、PM2.5和PM10质量浓度数据、PM2.5组分数据、卫星MODIS测量结果,探讨不同颗粒形态下的气象因素、颗粒物浓度分布、组分特征以及颗粒物光学特性的时间演变和垂直分布特征.结果表明:高湿、弱风等不利气象条件利于二次粒子的生成和累积,期间水溶性组分中SNA(SO₄^2-、NO₃^-、NH₄⁺)等二次组分浓度明显升高;同一时期长距离输入的沙尘发生的沉降对地面PM2.5化学组分构成显著影响,3月21日下午时段至3月22日在1.1².5 km高度的沙尘颗粒物向地面输送造成地面PM2.5的Ca²⁺突然增大到3.2μg/m³;3月22日下午以后在东南气流影响下,地面PM2.5向西扩散,PM2.5颗粒物浓度得到有效稀释,同时段出现了沙尘输入和扬尘过程,扬尘过程和沙尘输入使地面的粗颗粒增多,PM10剧增至347μg/m³;南京与无锡地区的颗粒物时空分布呈现高度相似的变化特点,具有区域性分布特征.后向轨迹分析表明,500 m、800 m及1000 m三个高度气团移动方向基本一致,主要从内蒙、京津冀、山东等地入海,后又经东海返回内陆抵达南京.     

细微大气颗粒物PM2.5影响因素研究

通过采样分析得知PM2.5质量浓度与温度、风速呈现非常显著的负相关关系,与相对湿度呈现非常显著的正相关关系,与大气压的相关性则比较弱。气象要素对PM2.5质量浓度的影响从主到次顺序依次是相对湿度、风速、温度、气压。     

基于激光雷达观测网的杭州及周边地区颗粒物污染特征研究

激光雷达观测网是研究区域大气颗粒物污染分布特征的有力工具。长三角地区激光雷达观测网部分站点的激光雷达资料与地面气象数据、PM2.5、PM10质量浓度数据,以及HYSPLIT后向轨迹模型模拟的后向轨迹相结合,对2016年9月杭州及其周边地区一次颗粒物污染的来源和成因进行了分析。分析结果表明,9月8日杭州颗粒物污染过程是该地区局地污染与高空输送共同作用的结果,且粗粒子主要来源于西北方向。杭州地区SO$_2$浓度整体较低,PM2.5浓度与NO$_2$浓度呈正相关,细颗粒物主要以硝酸盐为主。较高的NO$_2$浓度和高湿度、低风速的不利气象条件,是该地区局地细粒子快速增长的主要原因。     

成都秋冬季气溶胶消光系数的非平稳性分析

基于对大气消光系数时间序列随机性的深入研究,利用成都市2015至2017年秋冬季的大气能见度、相对湿度(RH)、颗粒物(PM10和PM2.5)质量浓度和NO2含量监测数据,反演得到该区域相应时段的气溶胶消光系数时间序列.基于位置、尺度、形状的广义可加模型检测了气溶胶消光系数时间序列的平稳性,并对气溶胶消光系数序列进行了协变量分析.实验结果表明,成都秋冬季气溶胶消光系数时间序列均为非平稳序列,其均值和方差表现为非线性变化.细颗粒物(PM2.5)质量浓度、RH和气溶胶组分(PM2.5/PM10)均是气溶胶消光系数序列非平稳变化的显著协变量.其中,PM2.5为气溶胶消光系数序列非平稳性最主要的贡献因子,其次为RH,贡献最小的为PM2.5/PM10,且气溶胶消光系数的爆发式增长与PM2.5、RH和PM2.5/PM10的协同作用密切相关.     

阿克达拉与阿勒泰市PM10与气象条件的\\[0.2cm]关系分析

对2010~2014年阿克达拉大气本底站和阿勒泰市的PM10质量浓度值、温度、降水、风向风速、湿度、气压数据进行了对比分析。结果表明：阿克达拉和阿勒泰市PM10年平均质量浓度均呈上升趋势,但是本底站值上升较快。当阿克达拉的平均气温在10~20℃时,阿勒泰市的平均气温低于-10℃时, 两地PM10质量浓度处于较高污染水平。相关性分析表明阿克达拉和阿勒泰市PM10质量浓度与降水、风速均呈负相关。当PM10质量浓度处于较高污染水平, 此时阿克达拉站主导风是西北风（NW）,风频达17.1%,风速在1.8~5.7 m·s^-1之间,且风速小于1.5 m·s^-1时的风频明显比风速大于1.5 m·s^-1时的风频小很多;阿勒泰主导风是N,风频为10.6%,风速在1.3~3.3 m·s^-1之间,风速小于1.5 m·s^-1时的风频与风速大于1.5 m·s^-1时的风频相差不明显。此外,分析表明PM10浓度与湿度、气压的相关性较弱。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.