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基于北斗B1C信号的DPE方法定位性能分析

doi:10.3969/j.issn.1003-3106.2023.05.002引用格式:金天,苏雨,纪永亮,等.基于北斗B1C 信号的DPE 方法定位性能分析[J].无线电工程,2023,53(5):1007-1014.[JIN Tian,SU Yu,JI Yongliang,et al.Analysis of Positioning Performance of DPE Method Based on BDS B1C Signal [J].RadioEngineering,2023,53(5):1007-1014.]基于北斗B1C 信号的DPE 方法定位性能分析金㊀天,苏㊀雨,纪永亮,鞠㊀易(北京航空航天大学电子信息工程学院,北京100083)摘㊀要:城市峡谷环境的高精度定位是全球卫星导航定位系统亟待解决的重要问题之一㊂近年来提出的直接位置估计(Direct Position Estimation,DPE)方法是基于导航域实现位置的最优估计,现有研究集中于全球定位系统(GlobalPositioning System,GPS)信号进行分析验证,缺乏新体制信号的对比和抗多径原理分析,并且计算量过大不易实现㊂针对以上问题,基于北斗卫星导航系统(BDS)B1C 信号,设计了一种快速DPE 软件接收机,并基于城市峡谷环境下的真实信号验证了BDS B1C 新体制信号DPE 软件接收机的实际性能㊂实际试验表明,相同信号相干积分长度和卫星几何精度因子情况下,DPE 接收机使用二进制偏置载波调制(Binary Offset Carrier,BOC)新体制信号相较于二进制相移键控(Binary Phase Shift Keying,BPSK)信号在城市峡谷环境下定位精度具有显著提升㊂关键词:最优估计;B1C 信号;直接位置估计;抗多径中图分类号:TN967.1文献标志码:A开放科学(资源服务)标识码(OSID ):文章编号:1003-3106(2023)05-1007-08Analysis of Positioning Performance of DPE Method Based onBDS B1C SignalJIN Tian,SU Yu,JI Yongliang,JU Yi(School of Electronic and Information Engineering ,Beihang University ,Beijing 100083,China )Abstract :High-precision positioning in urban canyon environment is one of the important issues that need to be solved urgently inthe global satellite navigation and positioning system.The direct position estimation (DPE)method proposed in recent years is theoptimal estimation of position based on the navigation domain .Existing research focuses on the analysis and verification of Global Positioning System (GPS)signals,lacks the comparison of new system signals and the analysis of anti-multipath principles,and thecalculation is too large to be implemented.To solve the above problems,a fast DPE software receiver based on BeiDou NavigationSatellite System (BDS)B1C signal is designed,and the practical performance of BDS B1C new system signal DPE software receiver based on the real signal in the urban canyon environment is verified.The experimental results show that under the same signal coherent integration length and satellite geometry accuracy factor,DPE receivers using new Binary Offset Carrier (BOC)system signals have asignificant improvement in positioning accuracy in the urban canyon environment as compared to the Binary Phase Shift Keying(BPSK)signals.Keywords :optimal estimation;B1C signal;DPE;anti-multipath收稿日期:2022-12-25基金项目:国家自然科学基金(62071020)FoundationItem:NationalNaturalScienceFoundationofChina(62071020)0㊀引言全球导航卫星系统(Global Navigation SatelliteSystem,GNSS)在城市峡谷环境下,因受到卫星可见性差㊁几何精度因子低和附近建筑物的信号反射等影响[1],反射或其他非视距(Non Line of Sight,NLOS)信号叠加在直达视距(Line of Sight,LOS)信号之上[2],限制了独立GNSS 导航终端的定位精度[3]㊂近年来,直接位置估计(Direct Position Estima-tion,DPE)方法为城市峡谷等复杂环境下使用GNSS 信号进行定位服务提供了一种新方法㊂DPE 接收机与传统GNSS 接收机分别对接收的卫星信号进行跟踪㊁再进行导航解算的两步法不同,其将码/载波跟踪环路和导航解算集成到一个步骤当中,通过对接收信号进行一步估计获取位置㊁速度和时间(Position,Velocity,and Time,PVT)信息[4]㊂2007年, Closas等[5]分别推导了传统两步法定位方法和DPE 定位方法的克拉美罗下界(Cramér-Rao Lower Bound,CRLB),证明了DPE方法定位性能不弱于传统定位方法㊂Closas等[6]提出了基于DPE方法的GNSS接收机结构设计与实现方法,通过仿真分析证明了这种接收机结构能够在多径传播和弱信号等复杂场景提供PVT信息㊂Gusi-Amigo等[7]对传统定位方法与DPE定位方法在加性高斯白噪声信道下的定位性能进行理论分析,并推导了DPE方法的近似Ziv-Zakai边界,理论结果表明DPE方法在低信噪比场景下具有更好的鲁棒性㊂Axelrad等[8]提出了一种集体检测的辅助GPS技术来实现快速捕获和直接定位,其通过正确组合卫星相关值来降低位置解算所需的载噪比,室外实验显示当使用1ms数据时其水平定位精度约为50m㊂Ng等[9]使用自主研发的软件平台Py-GNSS实现了利用NLOS 全球定位系统(Global Positioning System,GPS)信号进行城市导航的DPE方法,通过实验证明DPE方法在水平方向的定位误差比传统标量跟踪方法减少了40m㊂现有的基于DPE方法的接收机研究主要集中于GPS系统的二进制相移键控(Binary Phase Shift Keying,BPSK)调制信号进行,并未考虑二进制偏置载波调制(Binary Offset Carrier,BOC)新信号体制对DPE接收机性能的影响㊂北斗卫星导航系统(BDS)B1C信号作为北斗三号最主要的公开服务信号为全球用户提供高质量的定位㊁导航及授时服务[10]㊂不少学者对北斗三号的数据质量和定位性能进行了分析与评估[11-15]㊂然而上述分析均基于传统接收机结构进行理论和实验分析,缺乏DPE方法的性能评估㊂基于此,本文从B1C信号应用于DPE方法在弱信号㊁抗多径2个方面的优势进行分析,评估了其在城市峡谷环境下的定位性能㊂1㊀接收信号模型B1C信号是北斗三号系统导航定位服务主用新体制信号[16],载波频率为1575.42MHz,带宽为32.736MHz㊂由于其载波频率与GPS L1C/A㊁伽利略卫星导航系统(GALILEO)E1OS相同,与上述2个频点的导航信号能够实现兼容与互操作㊂B1C 信号为复合包络信号,包含2个正交分量:数据分量和导频分量㊂其中,数据分量采用BOC(1,1)调制;导频分量采用QMBOC(6,1,4/33)调制[17],由低频子载波BOC(1,1)和高频子载波BOC(6,1)组成㊂目前B1C信号支持宽带接收和窄带接收2种测量方法[18]㊂B1C接收信号经过射频前端滤波㊁放大㊁下变频和AD转换后,其中频信号可以表示为: r(tk)=ðN i=1{r i B1C_data(t k)+j r i B1C_pilot(t k)}+n(t k),(1) r i B1C_data(t k)=12D i B1C_data(t k,τi,f d i,t k)C i B1C_data(t k,τi,f d i,t k)㊃sc i B1C_data(t k,τi,f d i,t k,θi,0,f IF),(2) r i B1C_pilot(t k)=32C i B1C_pilot(t k,τi,f d i,t k)㊃sc i B1C_pilot(t k,τi,fd i,t k,θi,0,f IF),(3)式中:r i B1C_data(t k)为第i颗星的数据分量, r i B1C_pilot(t k)为第i颗星的导频分量,N为可见星总数量,t k为采样时间,τi为第i颗星的传播延时,f di,t k 表示t k时刻的多普勒频移,θi,0表示第i颗星的初始载波相位,f IF为信号中频载波频率,D i B1C_data表示第i颗星数据支路导航电文数据,C i B1C_data为第i颗星数据支路测距码,sc i B1C_data为第i颗星数据支路子载波,C i B1C_pilot表示第i颗星导频支路测距码,sc i B1C_pilot 表示第i颗星导频支路子载波㊂采用直接位置估计方法进行导航参数估计时需要将所有可见星的信号在导航域进行能量累加,之后通过一步估计得到导航解㊂城市峡谷弱信号环境下,所有可见星一个码周期的能量累加值难以实现精确的位置估计㊂为了减少算法计算量和复杂度,本文仅使用信号导频支路进行信号能量累加㊂一方面,B1C信号数据信道和导频信道功率比为1ʒ3;另一方面,B1C信号导频支路有10ms码周期,具有更大的相干积分增益㊂综上所述,B1C信号相比其他GNSS信号在DPE接收机城市峡谷环境应用中具有更明显的优势㊂根据以上分析,中频信号可以简化为:㊀㊀r(t k)=ðN sat=1{j A i C i B1C_pilot(t k,τi,f d i,t k)㊃sc i B1C_pilot(t k,τi,f d i,t k,θi,0,f IF)}+n(t k),(4)式中:A i为导频支路信号幅度㊂2㊀直接位置估计方法2.1㊀极大似然估计基于导航域的直接定位方法可以实现导航参数的最优估计[19]㊂DPE的导航域待求解是一个七维的状态矢量χ=[P T,v T,δt]T,P=[x,y,z]表示接收机在ECEF坐标系下的三维位置坐标向量,v=[v x, vy,v z]表示接收机地心地固(Earth-Centered Earth-Fixed,ECEF)坐标系下三维速度向量,δt表示时钟偏差㊂DPE方法的核心思想是建立用户接收机位置坐标与用户接收机接收信号中所有卫星的传输时延和多普勒频率之间的联系㊂DPE方法可以看作传统方法的逆过程㊂传统方法通过分别在不同信号处理通道最大化接收信号和本地产生的卫星PRN序列之间的相关性来估计不同可见星的传输时延和多普勒频率㊂DEP方法通过定义一组候选位置集,将候选位置集中的每一个位置元素与时间延迟紧密联系起来,以联合方式计算所有候选位置元素处的相关能量㊂本地复制信号可以看作是可见星信号的联合信号㊂最后,通过代价函数选择最大化相关性的候选位置元素作为估计位置㊂代价函数是从接收信号中获取PVT参数的最大似然估计,可以表示为:χ^=argmaxχ{ðM i=1Λi(τi(χ),f d i(χ))},(5)式中,M表示可见星数量,Λi(τi(χ),f d i(χ))表示候选位置χ处第i个可见星的预测信号和接收信号的相关值,该相关值大小由预测码相位和多普勒频率共同决定㊂2.2㊀2层网格搜索方法式(5)所示为七维的非凸函数优化问题,为了降低直接求解庞大的计算量,本文将其问题降阶为求解三维的非凸函数优化问题㊂钟差作为先验信息添加到预测信号的生成过程中㊂导航域的状态矢量简化为:χ=[x,y,z]T㊂(6)将式(6)带入式(5)可得简化后的代价函数为:χ^=argmaxχ{ðM i=1Λi(x,y,z)}㊂(7)因此,代价函数的求解仅与待求解位置相关㊂传统的DPE接收机使用二分搜索算法[20]或稀疏度不同的离散网格搜索算法[21]实现快速位置估计㊂城市峡谷环境下根据传统定位方法获取的先验位置预测值受多径影响具有较大误差,采用传统搜索方法对式(7)进行求解时存在定位精度差㊁计算复杂度高和局部收敛等问题㊂本文使用2层网格搜索算法对式(7)进行求解,具体步骤如下:①把传统定位方法获得的定位结果χ-=[x-,y-,z-]T作为当前接收机导航状态量的先验预测值㊂②以γ-为中心,生成第一层等间隔的离散网格点[χ-1,χ-2, ,χ-N]㊂综合考虑搜索范围和计算复杂度,本文选择网格间隔为10m,网格范围为ʃ100m㊂③将2中生成的离散网格点带入式(7),得到第一层网格的粗略位置估计值χ㊃=[x㊃,y㊃,z㊃]T㊂④以第一层网格搜索位置估计结果χ㊃为中心,生成第二层精细化等间隔的离散网格点[χ㊃1,χ㊃2, ,χ㊃M]㊂考虑到参数估计更高的分辨率,本文选择网格间隔为1m,网格范围为ʃ10m㊂⑤将4中生成的精细化离散网格点带入式(7),可以得到搜索范围内的全局最优解χ^=[x^, y^,z^]T㊂2层网格搜索算法具有以下3点优势:①第一层全局粗略搜索能够有效避免传统二分搜索算法在多径误差下由先验预测值误差引起的局部最优收敛;②第二层精细化网格搜索相较于稀疏度不同的离散网格搜索算法在先验预测值存在较大多径误差情况下能够有效提高参数估计精度;③相较于全局精细化搜索,2层网格搜索算法极大减小了搜索网格点数㊂为方便理解,以x㊁y二维搜索为例,2层网格搜索算法的原理如图1所示㊂图1㊀2层网格搜索算法原理Fig.1㊀Principle of two-level grid search algorithm3㊀多径误差分析影响GNSS接收机定位精度的误差主要包括电离层延迟㊁对流层延迟㊁卫星时钟误差㊁相对论误差和多径误差等㊂其中,卫星时钟误差㊁对流层延迟㊁电离层延迟和相对论误差等可以通过理论模型㊁差分技术来抑制或者消除㊂多径误差由于其与接收机周边环境的强相关性,是目前最难消除的误差之一㊂城市峡谷环境下,天线接收信号是直射信号与多个反射信号产生干涉后的合成信号㊂多径信号对传统接收机信号处理的影响主要体现在两方面:一方面,伪码跟踪环跟踪的是合成信号的伪码相位,合成信号与本地信号的相关函数会发生畸变,从而导致延迟锁相环(Delay Loop Lock,DLL)跟踪误差;另一方面,载波跟踪环通过利用本地载波与接收信号载波直接的相位差来动态调整本地载波相位,当接收信号为合成信号而不是直射信号时,二者之间存在偏差㊂多径信号对载波跟踪的影响远小于对伪码跟踪的影响,伪码跟踪误差可以达到百米量级,载波相位误差为厘米级㊂DPE方法根据相关能量直接进行位置估计㊂本地复制伪码与合成信号的相关运算,可以看作是伪码分别与直射信号和反射信号的相关值累加结果㊂根据式(4)可以得到B1C合成信号的自相关函数:㊀㊀RΣ(τ)=R(τ)+R M(τ)=R(τ)+ðM i=1αi R(τ-τi)cosϕi,(8)式中:R(τ)表示本地复制伪码与直射信号的相关函数,R M(τ)表示本地复制伪码与反射信号的相关函数,αi㊁τi㊁ϕi分别为第i个反射信号相对于直射信号的幅值㊁延时和相位㊂由于QMBOC(6,1, 4/33)信号绝大部分功率是由BOC(1,1)组成,为了减少相关时的计算量,本文使用BOC(1,1)信号相关函数进行后面的分析㊂一方面,BOC(1,1)信号相关函数如图2所示,相对于相同码速率的GPS L1BPSK调制信号更加陡峭,具有更好的多径分辨能力[22];另一方面,直接位置估计方法本身的抗多径性能相比传统定位方法更加优异,具体建模分析如下㊂本文以直射信号存在情况下,只有1条反射路径下的信号进行叠加为例进行数学建模㊂首先对相关函数进行归一化处理,可以将式(8)中相关函数分别表示为分段函数:R(τ)=-1-τ,τɪ[-1,-0.5)3τ+1,τɪ[-0.5,0)-3τ+1,τɪ[0,0.5)τ-1,τɪ[0.5,1)ìîíïïïï,(9)RM(τ)=-α1㊃(τ-τ1)㊃cosϕ1-α1㊃cosϕ1,τɪ[τ1-1,τ-0.5)3㊃α1㊃(τ-τ1)㊃cosϕ1+α1㊃cosϕ1,τɪ[τ1-0.5,τ1)-3㊃α1㊃(τ-τ1)㊃cosϕ1+α1㊃cosϕ1,τɪ[τ1,τ+0.5)α1㊃(τ-τ1)㊃cosϕ1-α1㊃cosϕ1,τɪ[τ+0.5,τ+1)ìîíïïïï,(10)式中:ϕ1ɪ[0,2π),α1ɪ[0,1]㊂当τ1小于0.5个码片时组合信号的相关函数可以表示为:RΣ(τ)=-1-τ,τɪ[-1,τ1-1)(-1-α1㊃cosϕ1)㊃τ+α1㊃cosϕ1㊃(τ1-1)-1,τɪ[τ1-1,τ1-0.5)(3+3㊃α1㊃cosϕ1)㊃τ+(1-3㊃τ1)㊃α1㊃cosϕ1+1,τɪ[τ1-0.5,0)(3㊃α1㊃cosϕ1-3)㊃τ+(1-3㊃τ1)㊃α1㊃cosϕ1+1,τɪ[0,τ1)(-3-3㊃α1㊃cosϕ1)㊃τ+(1+3㊃τ1)㊃α1㊃cosϕ1+1,τɪ[τ1,0.5)(1-3㊃α1㊃cosϕ1)㊃τ+(1+3㊃τ1)㊃α1㊃cosϕ1-1,τɪ[0.5,τ1+0.5)(1+α1㊃cosϕ1)㊃τ-(1+τ1)㊃α1㊃cosϕ1-1,τɪ[τ1+0.5,1)α1㊃(τ-τ1)㊃cosϕ1-α1㊃cosϕ1,τɪ[1,τ1+1)ìîíïïïïïïïïïïï㊂(11)㊀㊀根据式(11),当反射波幅值α1为0.5,延时τ1为0.4码片,相对相位ϕ1为0ʎ时,合成信号的相关函数如图2(a)所示,其他参数相同,相对相位ϕ1为180ʎ时,合成信号的相关函数如图2(b)所示㊂(a)同相(b)反相图2㊀BOC信号多径误差Fig.2㊀BOC signal multipath error由图2可以看出,不论多径信号同相还是反相,合成信号的自相关函数均不再关于0码片偏移量处左右对称㊂传统定位方法通过码环鉴别器不断调整本地复制伪随机码相位,直到超前和滞后相关器输出的相关结果E 与L 相等为止,此时码环跟踪误差等于0㊂多径信号引起的码相位测量误差是以自相关函数值相等的E 和L 水平连线线段中点至0码片偏移量处的水平距离δcp ㊂同相多径信号会使伪距测量值偏大,反相多径信号会使伪距测量值偏小㊂因此,传统两步法定位方法定位结果受多径信号影响较大㊂DPE 方法直接通过对相关峰最高值的位置估计进行位置解算,从图2中可以看出,多径信号的存在情况下合成信号的自相关函数峰值与直射信号的自相关函数峰值均位于同一相位处㊂因此DPE 方法能够有效抑制多径信号对定位精度的影响㊂4㊀实验结果及分析为了对BDS B1C 信号直接定位方法在城市峡谷环境的定位性能进行评估,本文搭建了基于DPE 方法的软件接收机性能评估平台,包括天线㊁功分器㊁多通道信号采集器㊁GNSS 软件接收机㊁DPE 软件接收机和数据分析模块㊂性能评估平台工作流程如图3所示㊂图3㊀性能评估平台半实物原理Fig.3㊀Semi-physical schematic diagram of performance evaluation platform㊀㊀为了模拟更加接近真实的城市峡谷环境,选择位于环形楼宇中心的实际信号采集点,数据采集环境如图4所示㊂图4㊀实测数据采集场景Fig.4㊀Measured data acquisition scene使用功分器将天线接收信号分为2路,分别通过多通道信号采集器采集中频数据,数据采集参数如表1所示㊂表1㊀数据采集参数Tab.1㊀Data acquisition parameters参数数值中频频率/MHz 27.92采样率/MHz 112前端带宽/MHz 40数据量化位数/b 1GPS GDOP5.61BDS GDOP5.75定位卫星数量5㊀㊀采集后的中频数据,一路数据由GNSS 软件接收机进行处理,另一路数据由DPE 软件接收机进行处理㊂数据分析模块完成2种软件接收机输出结果与标定基准坐标的对比分析㊂信号采集时GPS 卫星分布如图5所示㊂信号采集时刻播发BDS B1C 信号的卫星分布如图6所示㊂分别用传统软件接收机㊁DPE 软件接收机对采集到的实际信号进行处理,相关长度均为10ms㊂图7为BDS B1C 信号和GPS L1C /A 信号使用2种定位方法的定位误差比较㊂图5㊀GPS 卫星几何分布Fig.5㊀Geometric distribution of GPS satellites图6㊀BDS 卫星几何分布Fig.6㊀Geometric distribution of BDSsatellites图7㊀不同定位方法的定位误差Fig.7㊀Positioning errors of different positioning methods表2给出了实测信号2种定位方法定位误差的均值㊁标准差和均方根误差㊂表2㊀不同定位方法定位误差比较Tab.2㊀Comparison of positioning errors of different methods单位:m接收机类型信号类型均值标准差均方根误差SDR 接收机GPS L1C /A18.90 3.5519.24BDS B1C13.16 1.5613.25DPE 接收机GPS L1C /A14.03 2.7114.29BDS B1C10.342.7210.69㊀㊀可以明显看出,在实际城市峡谷环境下,DPE 接收机使用GPS L1C /A 信号和BDS B1C 信号相较于传统接收机均方根误差分别降低了25.7%㊁19.3%㊂因此,DPE 接收机相较于传统接收机在城市复杂环境下具有明显性能优势㊂使用相同相关长度情况下,BDS B1C 信号能够显著提高DPE 接收机的定位精度,相较于使用GPS L1C /A 信号平均误差和均方根误差分别降低了26.3%和25.2%㊂采用2层网格搜索算法在不降低定位精度的情况下,三维搜索位置点数从8120601降低为18522,计算量得到显著降低㊂为了分析实际城市峡谷环境下信号相关长度对定位性能的影响,图8为DPE 软件接收机分别处理BDS B1C 信号和GPS L1C /A 信号使用不同相关长度的定位误差对比㊂图8㊀不同相关长度的定位误差Fig.8㊀Positioning errors of different correlated lengths表3给出了2种信号在不同相关长度下定位误差的均值㊁标准差和均方根误差㊂可以看出,增加信号相关长度可以显著提高定位精度㊂BDS B1C 信号和GPS L1C /A 信号在30ms 相关长度下均方根误差相比10ms 相关长度分别提升约15.4%㊁9.7%㊂BDS B1C 信号在相同相关长度下的均方根误差均小于GPSL1C /A 信号㊂表3㊀不同相关长度定位误差比较Tab.3㊀Comparison of positioning errors of different correlated lengths定位方法信号类型信号相关长度/ms均值/m 标准差/m 均方根误差/mDPEBDS B1CGPS L1C /A1010.34 2.7210.69209.63 2.9710.07308.552.949.041014.03 2.7114.292013.53 2.3613.733012.652.5712.915㊀结束语本文对BDS B1C信号在DPE方法应用中的弱信号优势和抗多径性能进行了分析,设计实现了一种基于BDS B1C信号的快速DPE软件接收机,将BDS B1C信号体制设计的优异多径分辨能力和直接位置估计方法的抗多径原理相结合来提高接收机在城市复杂环境下的定位精度,并且应用提出的2层网格搜索算法在保证全局最优求解前提下极大地降低了全局搜索的计算量㊂在城市峡谷环境中开展的实际信号定位实验结果表明,30ms相关长度下基于BDS B1C信号的DPE接收机静态定位平均误差为8.55m,均方根误差为9.04m㊂城市峡谷环境静态定位时,同等条件下基于BDS B1C信号的DPE接收机定位精度明显优于传统接收机和基于GPS L1C/A信号的DPE接收机㊂验证了基于BDS B1C信号的DPE接收机在城市峡谷环境下的性能优势,具有一定的实际应用前景㊂参考文献[1]㊀XIE P,PETOVELLO M G.Measuring GNSS MultipathDistributions in Urban Canyon Environments[J].IEEETransactions on Instrumentation and Measurement,2015,64(2):366-377.[2]㊀BRAASCH M S.Performance Comparison of Multipath Mit-igating Receiver Architectures[C]ʊ2001IEEE AerospaceConference Proceedings.Big 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International Journal of Heat and Mass Transfer

姓名：闫永帅学号：03 班级1班International Journal of Heat and Mass Transfer国际传热传质杂志International Journal of Heat and Mass Transfer 70 (2014) 990–1002A numerical model for combined heat and mass transfer in a laminar liquid falling film with simplified hydrodynamics复合换热和传质层液体降膜与简化的流体力学数值模型摘要我们提出一个模型来描述：层流的流体降膜流过垂直等温金属板，同时吸收或释放热和质量的交换。

我们开始的构想是建立课比较的模型应用简单假设，例如匀速和薄膜厚度不变。

相反，我们接受一些影响像参数的变化和不同的热处理包括大体积的薄膜。

另外，焓的变化由于什么。

这些考虑的因素影响被讨论和比较。

这个数字化方案的获得通过利用N-B计划解决有限的不同的控制等式的构想来获得。

因为与墙体和相态边界相邻的浓度梯度期望它很大，因此我们在不规则的格子上分割等式。

模型的结果与建立的数据分析模型非常相适合。

我们发现减少不同的热处理方法包括主体的影响关系很小。

然而，温度贡献作为其中的一个变化参数的影响在同一个数量级。

而且，当在相同的条件下比较吸收和释放，吸收的质量传递速率比释放更高。

We present a model describing simultaneous heat and mass transfer of an absorbing or desorbing laminar liquid film flowing over a vertical isothermal plate. We start with a formulation which is comparable to established models by using simplifyingassumptions such as homogeneous velocity and constant film thickness. In contrast to those, we allow for effects like change in properties and differential heat of solution within the bulk of the film. Additionally, enthalpy transport due to interdiffusion is accounted for. The impact of the considered effects are discussed and compared.The numerical solution is obtained by utilising a Newton–Raphson scheme to solve the finite difference formulation of the governing equations. Since the temperature gradients adjacent to wall and phase boundary are expected to be large, we discretise the equations on an irregular grid. The results of the model agree very well with established analytical models.It is found that the influence of release d differential heat of solution within the bulk is relatively small. However, the impact on the temperature distribution is in the same order of magnitude as the one of a change in properties. Moreover, when comparing desorption with absorption under equivalent conditions, the mass transfer rate during absorption is higher than during desorption.1.引言热质交换自然发生也包括各种工艺仪器。

Guidelines for Tunnelling Risk Management

International Tunnel Association Working Group No. 2 Guidelines for Tunnelling Risk Management2002-10-21International Tunnelling Association,Working Group No. 2Guidelines for Tunnelling RiskManagement2002-10-21Revision 0Issue 2002-10-21Author Søren Degn Eskesen, Per Tengborg, Jørgen Kampmann, Trine Holst VeichertsContents0Abstract 51Introduction and scope 62Use of risk management 73Objectives of risk management 10 3.1Scope 10 3.2Risk objectives 10 3.3Risk management strategy 114Risk management in early design stages 13 4.1Establish risk policy 13 4.2Risk acceptance criteria 13 4.3Qualitative risk assessment 14 4.4Specific risk assessment 165Risk management during tendering and contractnegotiation 17 5.1Risk management during preparation of tenderdocuments 17 5.2Risk management during selection of contractor 19 5.3Risk clauses in contract 20 6Risk management during construction 22 6.1Contractor's risk management 22 6.2Owner's risk management 23 7Typical components of risk management 24 7.1Introduction 24 7.2Hazard identification 24 7.3Classification 257.4Quantitative risk assessment 328Risk management tools 34 8.1Fault tree analysis 34 8.2Event tree analysis 35 8.3Decision tree analysis 35 8.4Multirisk 36 8.5Monte Carlo simulation 379Glossary 3810References 390AbstractThe paper gives guidance to all those who have the job of preparing the overall scheme for the identification and management of risks in tunnelling and underground projects. The text provides owners and consultants with what is modern-day industry practice for risk assessment, and describes the stages of risk management throughout the entire project from concept to start of operation.1Introduction and scopeTunnelling and underground construction works impose risks on all parties involved as well as on those not directly involved in the project. The very nature of tunnel projects implies that any potential tunnel owner will be fac-ing considerable risks when developing such a project. Due to the inherent uncertainties, including ground and groundwater conditions, there might be significant cost overrun and delay risks as well as environmental risks. Also, as demonstrated by spectacular tunnel collapses and other disasters in the recent past, there is a potential for large scale accidents during tunnelling work. Furthermore, for tunnels in urban areas there is a risk of damage to a range of third party persons and property, which will be of particular con-cern where heritage designated buildings are involved. Finally there is a risk that the problems which the tunnelling project cause to the public will give rise to public protests affecting the course of the project.Traditionally, risks have been managed indirectly through the engineering deci-sions taken during the project development. These guidelines consider that pre-sent risk management processes can be significantly improved by using sys-tematic risk management techniques throughout the tunnel project develop-ment. By the use of these techniques potential problems can be clearly iden-tified such that appropriate risk mitigation measures can be implemented in a timely manner.The use of risk management from the early stages of a project, where major decisions such as choice of alignment and selection of construction methods can be influenced, is essential.The purpose of this document is to1.indicate to owners what is recommended industry best-practice forrisk management; and2.present guidelines to designers as to the preparation and implementa-tion of a comprehensive tunnel risk management system.For the purposes of this document "risk management" is the overall term which includes risk identification, risk assessment, risk analysis, risk elimi-nation and risk mitigation and control. See glossary in section 9.2Use of risk managementIn order to fulfil the scope these guidelines provide a description of risk management activities that may be used for tunnels and underground works. Below is shown how risk management may be used throughout the project from the early planning stage through to start of operation:•Phase 1: Early Design Stage (Feasibility and Conceptual Design) -Establish risk policy (section 4.1)-Risk acceptance criteria (section 4.2)-Qualitative risk assessment of the project (section 4.3)-Detailed analysis of areas of special interest or concern (section4.4)•Phase 2: Tendering & Contract Negotiation-Requirements in tender documents (section 5.1)-Risk assessment in tender evaluation (section 5.2)-Risk clauses in contract (section 5.3)•Phase 3: Construction Phase-Contractor's risk management (section 6.1)-Owner's risk management (section 6.2)-Joint risk management team between the owner and the contractor In phase 1 the responsibility of establishing a risk policy and carrying out risk assessment is the owner's alone. In phase 2 the potential contractor has certain input to the tender regarding risk management, but the owner is still the primary responsible party. In phase 3 however, the primary responsibil-ity moves on to the contractor to establish a risk management system and to carry out effective risk management. The owner should supervise, inspect and participate in this work. The owner should further continue to assess and mitigate risks not covered by the contractor.It is important that the risk management is performed in an environment of good cooperation between the parties. To achieve this, partnering may be a valuable tool. The process of partnering may be formulated as an exercise in encouraging good communications between the parties. It may be a formula for minimising cost to the owner while maximising profit for the contractor and encompasses joint planning and problem solving, scheduling, mitigationof delays and value engineering. The process of "partnering" may therefore be seen as a risk mitigation measure for the owner and the contractor.An overview of the risk management activities as seen from the owner's point of view is presented in figure 1. Risk assessments made by the contractor solely for his own purposes, such as the assessment of the risks he is involved in by submitting the tender, are not included.Owner Contractor Supervision and support ofcontractor's risk managementAssessment and mitigation of owner's riskEstablish risk management system Figure 1 - Risk management activity flow for owner and contractor Joint work in riskmanagement team3Objectives of risk managementThe identification of risks resulting from design and construction is an es-sential task early in a project. In order to form a common reference for all parties involved (e.g. the owner, designers, insurers and contractors) a con-struction risk policy should be established by the owner.A construction risk policy for the project may indicate:•scope,•risk objectives, and•risk management strategy.3.1ScopeAs an example, the scope may include the following risks or consequences: 1.Risk to the health and safety of workers, including personal injury and, inthe extreme, loss of life,2.Risk to the health and safety of third parties,3.Risk to third party property, specifically existing buildings and structures,cultural heritage buildings and above and below ground infrastructure, 4.Risks to the environment including possible land, water or air pollutionand damage to flora and fauna,5.Risk to the owner in delay to the completion,6.Risk to the owner in terms of financial losses and additional unplannedcosts.3.2Risk objectivesThe risk objectives may be given as general objectives supplemented by specific objectives for each type of risk. The general objectives of the con-struction risk policy could be that proper risk management throughout the project will be ensured at all stages of the project by the:•Identification of hazards•Identification of measures to eliminate or mitigate risks•Implementation of measures to eliminate or mitigate risks where economically feasible or required according to the specific risk ob-jectives or health and safety legislation.Economically feasible may be defined using the ALARP principle i.e. to reduce all risks covered to a level as low as reasonably practicable.The construction risk policy may indicate that emphasis should be placed on minimising overall risk by reducing the likelihood of occurrence of events with large consequences, e.g. with several fatalities or of significant political concern. This should be done if the owner considers low probability events with high consequences to be of more concern than high probability events with low consequences; even if the risk, expressed as probability times con-sequence, is the same.The construction risk policy may also include some general statements on allocation of risks between parties, e.g. a risk should be allocated to the party who has the best means for controlling the risk.For each type of risk, specific minimum risk objectives may be defined in addition to the general risk objectives. For example, the general public should be exposed only to a small additional risk from construction of the tunnel or underground works; compared to the risk they are exposed to as users of buildings, cars, bicycles, public transport and when walking in the adjacent streets.3.3Risk management strategyAs part of the construction risk policy a risk management strategy should be adopted. A recommended strategy is to carry out construction risk assess-ments at each stage of design and construction in accordance with the in-formation available and the decisions to be taken or revised at each stage. Any risk management strategy should include:• a definition of the risk management responsibilities of the various par-ties involved (different departments within the owner's organisation,consultants, contractors)• a short description of the activities to be carried out at different stages of the project in order to achieve the objectives• a scheme to be used for follow-up on results obtained through the risk management activities by which information about identified hazards (nature and significance) is freely available and in a format that can be communicated to all parties, which may best be accomplished by some form of comprehensive risk register•follow-up on initial assumptions regarding the operational phase •monitoring, audit and review procedures4Risk management in early design stages For effective risk management of a tunnelling project (or any other type of construction work) it is vital that risk management is begun as early as pos-sible, preferably during the project feasibility and early planning stages. The owner's risk policy sets the objectives of the exercise and existing members of the project team (and new members when they join the project team) should have the whole risk management process in their minds when carry-ing out their work.It is important to note that the success and benefits of implementing effec-tive risk management depends on the quality of the identified risk mitigating actions and on the active involvement, experience and general opinion of the participants (owner, designers and contractors).Risk management is not achieved by the enforcement of systems and proce-dures alone, but can be enhanced through seminars and meetings where an understanding and appreciation of the risk management objectives are dis-seminated throughout the organisations.4.1Establish risk policyThe primary step in establishing a risk management system is for the owner to formulate a risk policy as described in section 3.4.2 Risk acceptance criteriaThe risk objectives expressed in general terms in the owners risk policy should be "translated" into risk acceptance criteria suitable for use in the risk assessment activities planned to be carried out. This may include:•Risk acceptance criteria to be used in qualitative risk assessment. The risk classification shown in section 7.3.3 is an example of such criteria. •Risk acceptance criteria to be used in quantitative risk assessments. For each type of risk to be covered by a quantitative risk assessment theywould usually be expressed as:- A limit above which the risk is considered unacceptable and thus must be reduced regardless of the costs.- A limit below which it is not required to consider further risk re-duction.-An area between the two limits where risk mitigation shall be con-sidered and mitigation measures implemented according to the cir-cumstances, e.g. using the ALARP principle mentioned in section3.A document should be provided that explains how the risk acceptance crite-ria were established in relation to the statements on risk objectives in the owner's risk policy.4.3Qualitative risk assessmentDuring the early design stage, a qualitative risk assessment should be car-ried out focussed on the identification of potential hazards to the construc-tion activities expected to be included in the project, and covering all types of risk noted in the construction risk policy.The main purposes of this work is to raise the awareness of all concerned to the major risks involved in the construction and to provide a structured basis for the design decisions to be taken in the early design stage. The results can also be used for selection of specific topics for more detailed analyses as described in section 4.4. Finally the work can be used as starting point for the risk management during tendering.The timing of the qualitative risk assessment should be such that major de-sign changes are still possible. Depending on the time schedule of the early design it may be feasible to update the first qualitative risk assessment later in this design phase.The qualitative risk assessment should include:•Hazard identification. See section 7.2.•Classification of the identified hazards. See section 7.3. •Identification of risk mitigation measures.•Details of the risks in the project risk register indicating risk class and risk mitigation measures for each hazard.The identification and classification is best carried out through brainstorm-ing sessions with risk screening teams consisting of multi-disciplinary, technically and practically experienced experts guided by experienced risk analysts. The aim should be to identify all conceivable hazardous eventsthreatening the project including those risks of low frequency but high pos-sible consequence.In the identification and classification process due regard should be taken of common causes for hazardous events such as:•Complexity and maturity of the applied technology•Adverse unexpected ground and groundwater conditions •Technical and/or managerial incompetence•Human factors and/or human errors.•Lack of sufficient communication and co-ordination between internal and external interfaces•Combinations of several unwanted events that individually are not necessarily criticalThe identified hazards are classified according to the magnitude of the risk they represent. The purpose of this classification is to provide a framework for the decisions to be made on implementation of risk mitigation measures. Classification systems should be established covering frequencies and con-sequences as well as classification of risks on the basis of the frequency and consequence classes. The classification system may be included in the risk acceptance criteria, see section 4.2.The identification of risk mitigation measures may be carried out by the same or a different team and this team should preferably have a representa-tive of all the major parties to the project.Where risk levels conflict with the project's risk acceptance criteria, it is mandatory to identify risk-reducing actions and provide documentation for the management decision on which actions are to be implemented. The re-sults should be registered in the project risk register.Risk mitigation in this phase of the project will primarily result in changes in technical solutions and possibly in alternative working procedures. Fur-ther, many risk-reducing actions can be decisions or statements to be written into the tender documents.At this point it should be possible to establish whether implementation of a set of risk-mitigating actions will in fact reduce the risk to an acceptable level. If this does not appear to be the case, other approaches must be ex-plored.4.4Specific risk assessmentFor hazards of specific interest, e.g. due to the severity of the risk involved or the significance of the design decision to be taken, a more detailed risk analysis than the general qualitative analysis described in section 4.3 may be carried out. The outcome of this analysis should also be documented in the project risk register.The work may comprise one or more of the following:• A fault tree analysis of the causes of the hazards, see section 8•An event tree analysis of the consequences, see section 8• A full quantification of the risk, see section 7.4, e.g. with the purpose of evaluating the cost-benefit ratio of implementation of mitigating meas-ures or providing a quantitative basis for a decision between alternative courses of action.5Risk management during tendering and contract negotiation5.1Risk management during preparation of tenderdocuments5.1.1Main risk management activitiesThe following risk management activities should be carried out during preparation of the tender documents:•Specification of technical and other requirements in the tender docu-ments such that the risks are managed in accordance with the risk pol-icy. The results of the qualitative risk assessment carried out during the early design stage should be used as part of the basis.The specification of technical and other requirements should detail re-sponsibilities for risks in accordance with any general principlesadopted for the project covering allocation of risks. E.g. risks should be allocated to the party who has the best means for controlling them, as mentioned in section 3.2.•The qualitative risk assessment carried out in the early design stages should be repeated when the tender documents are near completion as the basis for final modifications of the tender documents and to docu-ment that risk has been managed in accordance with the risk policy.•Definition of the information requested from the tenderers in order to allow an evaluation of the tenderers' ability to manage risk and of the differences in risk between the proposals made by the different tender-ers. See section 5.1.2.•Specification of requirements in the tender document concerning the contractor's risk management activities during execution of the contract, see section 5.1.3.5.1.2Information to be provided with the tenderIn order to ensure a basis for comparing and evaluating the tenderers, the tender documents should state the information that each tenderer must pre-sent in this respect. This information should include:•Information on structured risk management in similar projects and their outcomes•CV for persons to be responsible for the risk management and details of any specialist organisation that has been involved•General description of the tenderer's intentions regarding his project-specific organisation and his risk management objectives•Overview and description of the major risks perceived by the tenderer in the project•The tenderer’s proposed strategy for the management of major risks to the project and how success will be defined and measured.It should be stated that some or all of the above information provided by the tenderers will be used as a basis for the owner's tender evaluation. The in-formation will help to illustrate whether the contractor is capable of carrying out the necessary systematic risk analysis, and the expected risk manage-ment performance.5.1.3Requirements to be specified in the tender documentsThe tender documents should specify that the contractor must perform risk management in accordance with the owner's risk policy. The contractor's risk management system and approaches must be compatible with the owner's, thereby reducing and controlling risks both to himself, to the owner and the public.Requirements concerning the contractor's risk management system should be described. This could include such matters as:•Organisation and qualifications of risk management staff•Types of risks to be considered and evaluated. These will be concerned with construction issues and any related design activities under the con-tractor's control.•Activities, i.e. description of a minimum requirement of activities to be included in the contractor's risk management, including systematic risk identification, classification of risks by frequency and consequence, and identification of risk elimination and risk mitigating measures•Time schedule for risk management activities (including requirements to carry out risk assessment in time to allow implementation of identi-fied risk mitigating measures)•Co-ordination with the owner's risk management and risk management team•Co-ordination with the other contractors' risk management•Co-ordination between risk management and the contractor's other sys-tems, such as quality management and environmental management.•Control of risks from sub-contractors’ activities•Specific requirements concerning risk management in explicit fields should be stated (examples could be modification to the construction methods for areas identified as of particular concern, i.e. construction methods related to risk to third party buildings or requirements concern-ing securing against unintentional ground water lowering)The owner's risk policy, risk acceptance criteria and risk classification sys-tem should be stated in the tender documents. The owner's risk management activities should be briefly mentioned. It should be carefully considered and pointed out to what extent the contractor will have insight into the owner's risk analysis results. Further, it should be stated in the tender documents that the contractor is responsible for effective risk management regardless of the extent and detail of the risk information deriving from the owner.It is recommended that the tender documents require that the owner be in-volved in the risk management during construction and that a risk manage-ment team is established with participants from the contractor and from the owner (see figure 1).5.2Risk management during selection of contractor Providing tenderers are clearly informed in tender documents, the applica-tion of risk management techniques by the owner can be valuable in the se-lection of the successful tenderer. Identifying risk issues in the tenders can be used as a basis for tender negotiations. The evaluation of tenders in re-spect of risk may be qualitative (based on a points system) or on a quantita-tive basis to the extent that the tender price might be adjusted accordingly.The evaluation of the risk issues in the tenders should include:•An evaluation of the contractor's ability to identify and control risks by the choice and implementation of technical solutions. An evaluation is also needed of his ability to apply systematic risk management in the work that he will undertake;•Systematic assessment of the differences in risk between the project proposals by different tenderers;•Evaluation of the risk management expertise at the contractor's disposalWhere a qualitative risk assessment is envisaged, the means of achieving this need to be considered during the preparation of the tender documenta-tion. For each identified risk, the tenders need to be compared and areas where there are differences should be highlighted.Where a quantitative risk assessment is envisaged, the recommended ap-proach is first to carry out a quantitative risk assessment on the owner's pro-ject as described in Section 7.4. This could be carried out in the time period between the issue and the receipt of tenders. The risk in each tender is quantified by taking the owner's quantitative risk assessment and for each risk considering the differences in frequency and consequence. The input to the quantification could be obtained from reliable information obtained from external sources and/or through brainstorming sessions. The experience and competence of those on the brainstorming team is vital. The final outcome will be the quantification of the risks involved in each tender. This has the benefit of a level comparison even if the absolute value of the risk is uncer-tain.This quantification is particularly useful for the risk of economic loss to the owner, and the risk of delay to the completion of the project. These evalua-tions could be directly compared with the contract price in the tenders and the assignment of a certain monetary value might be made per month's esti-mated or potential delay of project completion.For other risks it may be more difficult to obtain reliable results from a full quantification analysis, and a qualitative comparison may be all that is practi-cable.5.3Risk clauses in contractWhen a contractor has been chosen, negotiations between the owner and the contractor may lead to a detailed contractual description of the risk man-agement system to be implemented on the project. This may be based on a combination of the intentions of the owner and the suggested procedures of the contractor with the purpose of improving the co-operation between the parties.Alternative technical solutions will also be negotiated on the basis of risk assessments carried out and stated in the contract.The risk assessment of the successful tender may have identified some pre-viously undetected areas of risk or special concern. In order to reduce these risks to an acceptable level, additional risk mitigation clauses may be intro-duced in the contract. An example could be that the contractor has proposed a modification to the construction methods envisaged by the owner, which is advantageous except for a secondary risk of impact to the environment. This risk to the environment is then mitigated by additional requirements.6Risk management during constructionIn the early design and tender and contract negotiation phases certain risks may be transferred, either contractually or through insurance, others may be retained and some risks can be eliminated and/or mitigated. In the construc-tion phase, possibilities of risk transfer are minimal and the most advanta-geous strategy for both owner and contractor is to reduce the severity of as many risks as possible through the planning and implementation of risk eliminating and/or risk mitigating initiatives.6.1Contractor's risk managementBased on what has been agreed in the contract, the contractor's responsibil-ity could be as proposed in figure 1. The contractor is responsible for the fulfilment of the owner's risk policy and should start by establishing a care-fully planned, well-structured and easy-to-use risk management system. The structure of the risk management system is of great importance for the straightforwardness of the further work with detailed identification of haz-ards and assessment of risks. See section 7.The contractor must identify hazards and classify risks using systems which are compatible with the systems used by the owner (see section 7.2 and 7.3) and should propose mitigation measures to reduce the identified risks. In cases where the implementation of the mitigation measures could lead to major delay or could in any other way cause a loss to the owner, the owner should approve the intended mitigation prior to its implementation.The contractor's risk management strategy should be implemented by all members of his staff whatever their job functions. The identification of haz-ards and control of risk, and the techniques involved, should be seen as an essential part of all the design and construction activities of the project. In-formation and training should be given, as necessary, to all personnel throughout the project. The owner should be invited to be present and to participate in the contractor's risk management meetings, presentations and training sessions.Timely consideration and actions are of the essence in risk mitigation meas-ures. The aim is to anticipate, and put in place effective proactive preventa-。

我国乏燃料后处理经济性研究

我国乏燃料后处理经济性研究赵弥彭海成董博(国家国防科技工业局核技术支持中心北京 100071)摘要：随着我国核能产业快速发展，天然铀需求和所产生乏燃料的数量也逐年增加，后处理产业的经济性必然会再次成为发展闭式核燃料循环产业需要解决的问题之一。

该文参考经合组织核能署相关研究，开展乏燃料后处理经济性分析，对“一次通过”和后处理两种核燃料循环方式的成本进行测算。

结果显示，现阶段后处理方案比“一次通过”更加经济，并且随着天然铀价格的持续上涨与后处理、MOX燃料制造技术成熟所带来的价格下降，其经济性将在未来愈发凸显。

关键词：核燃料循环乏燃料后处理经济性中图分类号：F426.61;F426.23文献标识码：A 文章编号：1672-3791(2023)12-0252-05 Research on the Economy of Irradiated Fuel Reprocessing in ChinaZHAO Mi PENG Haicheng DONG Bo(Nuclear Technology Support Center of SASTIND, Beijing, 100071 China)Abstract: With the rapid development of China's nuclear energy industry, the demand for natural uranium and the amount of produced spent fuel are also increasing year by year, and the economy of the reprocessing industry will inevi‐tably become one of the questions that need to be answered in the development of the closed nuclear fuel cycle industry again. This study refers to relevant research from the OECD Nuclear Energy Agency, analyzes the economy of spent fuel reprocessing, and calculates the costs of two nuclear fuel cycle methods of "once-through" and reprocessing. The results show that the reprocessing scheme is more economical than "once-through" at this stage, and its economy will become increasingly prominent in the future with the continuous rise of the price of natural uranium and the decrease of the price caused by the maturity of reprocessing and MOX fuel manufacturing technology.Key Words: Nuclear fuel cycle; Spent fuel; Reprocessing; Economy近年来，随着世界各国积极推进“碳达峰、碳中和”，以及更安全的核电机组投运，核能产业开始逐渐复苏。

2013年十大中国经济新闻

Die Top-Ten-Wirtschaftsmeldungen 20131. Stabiles Wirtschaftswachstum (稳定的经济增长)Chinas Wachstum ist zurück auf Kurs und kann die Zielvorgabe von 7,5 Prozent einhalten.中国的经济增长回到正轨,并保持7.5 ％的增长目标。

2. Freihandelszone in Shanghai (上海自由贸易区)Im August bewilligte der Staatsrat die Einrichtung einer Freihandelszone in Shanghai. Bis zum 22. November zogen insgesamt 1434 Unternehmen in die Zone.今年八月，国务院批准在上海设立自由贸易区。

直到11月22日共有1434家企业入驻开发区。

3. Finanz- und Steuerreformen (财政和税收改革)Die Chinesische Volksbank (PBC), die Zentralbank des Landes, hat am 20. Juli die bislang streng reglementierten Zinssätze für Kredite nach unten freigegeben. Das könnte zu mehr Wettbewerb un ter den Banken führen und Kredite für Privatunternehmen leichter zugänglich machen.中国人民银行（ PBC）——中国的中央银行，在7月20日起全面放开金融机构贷款利率管制。

[英文]联合国2013年度回顾

OPCW inspector Kieran Carey: “The OPCW as an organization has been awarded this year’s Nobel Prize, Peace Prize. Congratulations! Now get back to your tasks, there are tight deadlines to meet.”
Terror attacks from Boston to Nairobi shocked and saddened the world. Fear of terror led to distrust and provided an excuse for widespread internet and cell phone surveillance programs which affected ordinary citizens and world leaders alike.
The first-ever high-level Meeting of the General Assembly on Nuclear Disarmament heard a keynote address by Iranian President Hassan Rouhani: “The world has waited too long for nuclear disarmament. The indefinite possession of nuclear weapons cannot be tolerated, nor can their complete elimination be further delayed.”
UK Foreign Secretary, William Hague: “The failure of the council to tackle the crimes committed on a daily basis has resulted in a culture of impunity in which a brutal regime believed it could get away with murdering its own men, women and children.”

International Communications in Heat and Mass Transfer

7Numerical simulation of residual stress andbirefringence in the precision injection molding of plastic microlens arrays Original Research ArticleInternational Communications in Heat and Mass Transfer,Volume 36, Issue 3, March 2009, Pages 213-219Can Weng, W.B. Lee, S. To, Bing-yan JiangClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractMicrolens arrays are critical components in the assembly of display devices usedin various telecommunication products. The optical quality of these plastic lensesis very sensitive to the presence of residual stress. In this paper the distribution ofresidual stress and birefringence of these microlens arrays has been investigated.It is found that maximum residual stress always occurs in the regions near thegate. The predicted trends and patterns of the residual stress and birefringencedistribution agree well with the experimental results. The effects of six mainprocessing parameters on maximum value of residual stress are studied. Thenoticeable discrepancy between the simulation and the experimental results are discussed.Article OutlineNomenclature1. Introduction2. Mathematical modeling3. 3D numerical simulation4. Experimental verification5. Effects of processing factorsPurchase6. Results and discussion7. Conclusions AcknowledgementsReferences8Automated manufacturing environment to address bulkpermeability variations and race tracking in resintransfer molding by redirecting flow with auxiliarygatesOriginal Research ArticleComposites Part A: Applied Science and Manufacturing,Volume 36, Issue 8, August 2005, Pages 1128-1141Jeffrey M. Lawrence, Peter Fried, Suresh G. AdvaniClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractLiquid Composite Molding (LCM) processes inject a resin into a closed moldcontaining fiber preforms to manufacture a polymeric composite. Many a times,resin does not fully saturate the fiber perform causing one to discard thecomposite part as scrap. In order to make LCM processes more reliable, ascientific understanding of the resin flow and impregnation into the porousnetwork containing fiber preform can lead to advanced manufacturing techniqueswhich can rely on flow control approaches to improve the yield. The flow is usuallycontrolled by redirecting the resin flow by strategically opening and closingauxiliary injection gates as dictated by the flow monitoring sensor system. Thereare various approaches to generating such strategies. Once such technique,scenario-based control, has exhibited the potential to compensate for flowdisturbances such as race tracking. However, a flexible and reliablemanufacturing environment is needed in order to carry out experiments inadvanced LCM processing. For this, an automated Resin Transfer Moldingapparatus was designed and built, containing all of the necessary components.Flow sensors allow for the monitoring of the fluid advancement. IndividuallyPurchasecontrollable injection gates and vents allow for geometrical flexibility and flow control. The following study demonstrates usefulness of the manufacturing tool to implement, validate and uncover limitations of a scenario-based flow control approach with geometries of increasing complexity.Article Outline1. Introduction1.1. Liquid composite molding processes1.2. Modeling and simulation1.3. Disturbances/variations in the process2. RTM workstation2.1. Mold2.2. Flow distribution system2.3. Sensor plate2.4. Controlling computer3. Flow control during filling4. Selected geometries for study4.1. Fender geometry4.2. Engine hood geometry4.3. Windows geometry5. Limitations5.1. Mode detection sensitivity5.2. Separation of mode detection and control5.3. Need for parameters6. ConclusionsAcknowledgementsReferences9 Multivariate regression modeling for monitoring quality of injection moulding components using cavity sensortechnology: Application to the manufacturing ofpharmaceutical device components Original Research ArticleJournal of Process Control , Volume 21, Issue 1, January 2011, Pages 137-150Magida Zeaiter, Wendy Knight, Simon HollandClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractThere is an increased demand within the moulding industry to improve the quality of moulded parts by maintaining consistent tolerances and overall dimensions. This interest is more important in areas of the moulding industry that are dedicated to pharmaceutical devices, where a quality by design approach is now expected to be adopted. A pharmaceutical device is an assembly of different plastic components which are manufactured by injection moulding; many have critical quality parameters which affect not only the device appearance but also more importantly its performance for drug delivery. Hence, the need of better understanding and control of injection moulding processes. This study presents the use of multivariate regression modeling approach to monitor the quality of the final product using cavity sensor technology (CST). The influence of the injection moulding process parameters on the quality of the final parts have beeninvestigated using a design of experiment approach. The results demonstrate that the Partial Least Squares (PLS) regression model based on cavity pressure sensor data could be successfully used to monitor the quality (weight, dimensions) of the final product in plastic injection moulding.Article Outline1. Introduction2. Background on injection moulding process3. Experimental conditionsPurchase4. Data summary5. Multivariate regression modeling of pressure cavity sensor data5.1. Model building 5.2. Results5.2.1. Model building – cross validation 5.2.2. Model validation and testing5.2.2.1. Dependent test 5.2.2.1.1. Discussion 5.2.2.2. Independent test 5.2.2.2.1. Weight 5.2.2.2.2. Dimensions6. Discussion and conclusion Acknowledgements References10In-line process conditions monitoring expert system forinjection molding Original Research ArticleJournal of Materials Processing Technology , Volume 101,Issues 1-3, 14 April 2000, Pages 268-274Felix T. S. Chan, Henry C. W. Lau, Bing Jiang Close preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractInjection molding is one of the most important and efficient manufacturing industries in Hong Kong and China, and has the capability to manufacture high-value-added products. Optimizing process parameters in-line is difficult to achieve due to a large number of factors being involved and the time-limited restriction. This paper describes a monitoring expert system, which is able to predict the developing trends of injection molding operation parameters. In addition, this system provides expert advice on the appropriate actions to bePurchasetaken before the occurrence of quality problems. The knowledge representation, the structure of the knowledge base, and the inference engine of the monitoring expert system are presented in this paper. One of the main objectives of the research project is to assist operators for quick response in-line, and thus to ensure the quality of the product and improve the production rate. Practicalexamples regarding the use of this monitoring expert system for a plasticmolding company are also included.Article Outline1. Introduction2. Literature review3. Outline of the expert system — MCMES4. Knowledge base and knowledge representation5. Inference engine6. On-site tests of the MCMES7. Evaluations and benefits8. ConclusionReferences11Mechanical failure classification for spherical rollerbearing ofhydraulic injection molding machine usingDWT–SVM Original Research ArticleExpert Systems with Applications, Volume 37, Issue 10,October 2010, Pages 6742-6747Guang-ming XianClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractThis paper presents a combined discrete wavelet transform (DWT) and supportvector machine (SVM) technique for mechanical failure classification ofPurchasespherical roller bearing application in high performance hydraulic injection molding machine. The proposed technique consists of preprocessing the mechanical failure vibration signal samples using Db2 discrete wavelet transform at the fourth level of decomposition of vibration signal for mechanical failure classification. After feature extraction from vibration signal, support vectormachine is used for decision of mechanical failure types of the spherical rollerbearing. The classification results indicate the effectiveness of the combinedDWT and SVM based technique for mechanical failure classification of hydraulicinjection molding machine.Article Outline1. Introduction2. Spherical roller bearing application in hydraulic and hybrid injection moldingmachines3. Discrete wavelet transform4. SVM approach for classification5. Experimental results and analysis5.1. Classification performance comparison of mechanical failure using differentmethods5.2. Kernel function and parameters selection of SVM for mechanical failureclassification5.3. Noise analysis for the proposed DWT–SVM technique6. ConclusionAcknowledgementsReferences12PSO-based back-propagation artificial neural networkfor product and mold cost estimation of plasticinjection molding Original Research ArticleComputers & Industrial Engineering, Volume 58, Issue 4,May 2010, Pages 625-637PurchaseZ.H. CheShow preview | Related articles | Related reference work articles13Closed-loop flow control in resin transfer molding usingreal-time numerical process simulations OriginalResearch ArticleComposites Science and Technology , Volume 62, Issue 2,February 2002, Pages 283-298 D. R. Nielsen, R. PitchumaniShow preview | Related articles | Related reference work articlesPurchase14Flow sensing and control strategies to addressrace-tracking disturbances in resin transfermolding —part II: automation and validation OriginalResearch ArticleComposites Part A: Applied Science and Manufacturing , Volume 36, Issue 11,November 2005, Pages 1581-1589 Mathieu Devillard, Kuang-Ting Hsiao, Suresh G. AdvaniShow preview | Related articles | Related reference work articlesPurchase 15Near infrared spectroscopy for in-line monitoring during injection moulding Original Research Article。

碱激发复合体系快速胶凝材料的性能研究

研究探讨碱激发矿渣胶凝材料是指以强碱为激发剂，以水淬高炉矿渣为被激发材料的一种新型胶凝材料，与传统的水泥基材料相比，碱激发矿渣胶凝材料具有快硬早强、优良的耐化学侵蚀性、耐高温性和固结重金属的性能等[1,2]，可在部分环境替代水泥制备新型胶凝材料，其应用可显著减少碳排放[3,4]，符合我国“碳达峰、碳中和”的绿色发展之路，是《2030年前碳达峰行动方案》和《建材行业碳达峰实施方案》等国家或部委鼓励推广应用的新型胶凝材料。

现实生活中，一些交通道路老化，出现局部坑洞需要修复；城市更新时各种地下管线的埋设或维修频繁，也经常破坏道路，如何减少道路局部修复对交通的影响，需要充分考虑。

另外，在一些极端条件下，比如地震、自然灾害、战争等影响，一些公路、桥梁、机场等基础设施极易受损，但其又是灾后救援行动的生命线，灾后交通的快速修复是保障国家社会经济活动正常运转和及时挽回人民生命财产的必要条件，这些都急需研发高性能的道路快速修补材料[5-8]。

本文以磨细矿渣、加密硅灰、碱激发剂、粗细骨料和钢纤维为原材料制备复合胶凝体系道路快速修补材碱激发复合体系快速胶凝材料的性能研究*黄启林（三明市公路事业发展中心，福建三明365004）摘要：为测试前期研发的碱激发复合体系快速胶凝材料的工程应用性能，采用优选的两种配合比用于工程试验段，并测试了碱激发复合体系快速胶凝混凝土不同龄期的抗压、抗折强度、耐久性和耐磨性等性能，并进行了相关分析。

结果表明：①优选的两种碱激发复合体系快速胶凝材料的配合比，4h 抗折强度分别达到4.5MPa 和4.7MPa ，满足道路快速抢修和通车的要求；②地聚物早期强度增长较快，后期强度增加较慢，不存在后期强度衰减的情况；③两种配合比的单位面积磨耗量分别为2.45kg/m 2和2.26kg/m 2，渗水高度分别为8mm~12mm 和5mm~8mm ，28d 收缩量分别为508×10-3mm 和412×10-3mm ，28d 碳化深度值分别21.1mm 和18.2mm 、氯离子渗透深度分别为10.3mm 和8.2mm ；④掺加钢纤维有利于提高地聚物的抗压和抗折强度，有利于提高其耐久性能。

Texas Instruments TI-RFid 高频读写器IC TRF7960 TRF7961产

RFID SystemsProduct Speciﬁ cationsOverviewTexas Instruments Radio Frequency Identiﬁ cation Systems is an industry leader in RFID technology, and the world’slargest integrated manufacturer of TI-RFid™ tags, TI-RFid smart labels, and TI-RFid reader systems. With more than1 billion RFID tags manufactured, TI-RFid technology is used in a broad range of RFID applications worldwide. TI isan active member of many standards bodies, including ISO, ISO/IEC, ECMA International, ETSI, and several nationalstandardization bodies working to drive the adoption of global standards for RFID technology. Array/rﬁ d Call 1-800-962-RFID(7343)* Dependent on the conﬁ guration used, the RF regulation in country of use and the environmental conditionRFIDTag-it™ HF-I Standard Transponder Inlays/rﬁ dCall 1-800-962-RFID(7343)SPAT178A© 2010 Texas Instruments Incorporated Printed in U.S.A.Printed on recycled paperRFID010208AEurope, Middle East and Africa (EMEA)European Toll Free* 00800 275 83927International +49 (0) 8161 80 2121Russian Support +7 (495) 981 07 01*The European Toll Free number is not active in all countries. If you havetechnical difficulty calling the toll-free number please use the international numberFax: +49 (0) 8161 80 2045Business Hours (Central European Time)Monday – Wednesday 10:00 – 18:00Tuesday – Thursday 09:00 – 18:00Friday 09:00 – 16:00E-mail:******************Texas Instruments Deutschland GmbH RFID Systems Haggertystrasse 1D-85350 Freising GermanyImportant Notice: The products and services of Texas Instruments Incorporated and its subsidiaries described herein are sold subject to TI’s standard terms and conditions of sale. Customers are advised to obtain the most current and complete information about TI products and services before placing orders. TI assumes no liability for applications assistance, customer’s applications or product designs, software performance, or infringement of patents. The publication of information regarding any other company’s products or services does not constitute TI’s approval, warranty or endorsement thereof.The platform bar, TI-RFid and Tag-it are trademarks of Texas Instruments.All other trademarks are the property of their respective owners.TI RFID Worldwide Technical SupportInternetTI RFID Home Page/rfidProduct Information CentersUS and CanadaPhone 800-962-RF I D (7343)Fax: 214-567-7343Business Hours (Central Standard Time)Monday – Friday 8:00 am – 5:00 pm E-mail:******************Texas InstrumentsRadio Frequency Identification System 6550 Chase Oaks Blvd., MS 8470Plano, Texas 75023USAApplicationsPartner with TI, the technology leader in application-speciﬁ c RFID solutions, for turnkey end-to-end formulas to employ RFID in speciﬁ c tracking models such as recycling, waste management and high value asset tracking – to name a few. The integration of TI-RFid™ products into proven application models, in conjunction with third party Developers Network partners gives customers the ability to adapt an end-to-end RFID asset tracking solutions for their business, without costly mistakes or development time. TI’s RFID Application Solutions are state-of-the-art design and system models for unique vertical business needs that result in lower overall system cost and faster, more efﬁ cient roll-outs. Learn more at /rﬁd-applicationsIMPORTANT NOTICETexas Instruments Incorporated and its subsidiaries(TI)reserve the right to make corrections,modifications,enhancements,improvements, and other changes to its products and services at any time and to discontinue any product or service without notice.Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty.Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty.Except where mandated by government requirements,testing of all parameters of each product is not necessarily performed.TI assumes no liability for applications assistance or customer product design.Customers are responsible for their products and applications using TI components.To minimize the risks associated with customer products and applications,customers should provide adequate design and operating safeguards.TI does not warrant or represent that any license,either express or implied,is granted under any TI patent right,copyright,mask work right, or other TI intellectual property right relating to any combination,machine,or process in which TI products or services are rmation published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement e of such information may require a license from a third party under the patents or other intellectual property of the third party,or a license from TI under the patents or other intellectual property of TI.Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties,conditions,limitations,and notices.Reproduction of this information with alteration is an unfair and deceptive business practice.TI is not responsible or liable for such altered rmation of third parties may be subject to additional restrictions.Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice.TI is not responsible or liable for any such statements.TI products are not authorized for use in safety-critical applications(such as life support)where a failure of the TI product would reasonably be expected to cause severe personal injury or death,unless officers of the parties have executed an agreement specifically governing such use.Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications,and acknowledge and agree that they are solely responsible for all legal,regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications,notwithstanding any applications-related information or support that may be provided by TI.Further,Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications.TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or"enhanced plastic."Only products designated by TI as military-grade meet military specifications.Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk,and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS16949requirements.Buyers acknowledge and agree that,if they use any non-designated products in automotive applications,TI will not be responsible for any failure to meet such requirements.Following are URLs where you can obtain information on other Texas Instruments products and application solutions:Products ApplicationsAmplifiers Audio /audioData Converters Automotive /automotiveDLP®Products Communications and /communicationsTelecomDSP Computers and /computersPeripheralsClocks and Timers /clocks Consumer Electronics /consumer-appsInterface Energy /energyLogic Industrial /industrialPower Mgmt Medical /medicalMicrocontrollers Security /securityRFID Space,Avionics&/space-avionics-defenseDefenseRF/IF and ZigBee®Solutions /lprf Video and Imaging /videoWireless /wireless-appsMailing Address:Texas Instruments,Post Office Box655303,Dallas,Texas75265Copyright©2010,Texas Instruments Incorporated。

Sensirion SGP30 气体传感器数据手册说明书

Datasheet SGP30Sensirion Gas Platform▪ Multi-pixel gas sensor for indoor air quality applications ▪ Outstanding long-term stability▪ I 2C interface with TVOC and CO 2eq output signals ▪ Very small 6-pin DFN package: 2.45 x 2.45 x 0.9 mm 3 ▪ Low power consumption: 48 mA at 1.8V ▪ Tape and reel packaged, reflow solderableBlock DiagramFigure 1 Functional block diagram of the SGP30.Product SummaryThe SGP30 is a digital multi-pixel gas sensor designed for easy integration into air purifier, demand-controlled ventilation, and IoT applications. Sensirion’s CMOSens ® technology offers a complete sensor system on a single chip featuring a digital I 2C interface, a temperature controlled micro hotplate, and two preprocessed indoor air quality signals. As the first metal-oxide gas sensor featuring multiple sensing elements on one chip, the SGP30 provides more detailed information about the air quality.The sensing element features an unmatched robustness against contaminating gases present in real-world applications enabling a unique long-term stability and low drift. The very small 2.45 x 2.45 x 0.9 mm 3 DFN package enables applications in limited spaces. Sensirion’s state-of-the-art production process guarantees high reproducibility and reliability. Tape and reel packaging, together with suitability for standard SMD assembly processes make the SGP30 predestined for high-volume applications.1Sensor Performance 1.1Gas Sensing PerformanceAccuracy ethanol signalFigure 2Typical and maximum accuracy tolerance in % of measured value at 25°C, 50% RH and typical VDD. The sensors have been operated for at least 24h before the characterization. Accuracy H2 signalFigure 3Typical and maximum accuracy tolerance in % of measured value at 25°C, 50% RH and typical VDD. The sensors have been operated for at least 60h before the characterization.1 Exposure to ethanol and H2 concentrations up to 1000 ppm have been tested. For applications requiring the measurement of higher gas concentrations please contact Sensirion.2 ppm: parts per million. 1 ppm = 1000 ppb (parts per billion)3 90% of the sensors will be within the typical accuracy tolerance, >99% are within the maximum tolerance.4 The long-term drift is stated as change of accuracy per year of operation.5 Test conditions: operation in 250 ppm Decamethylcyclopentasiloxane (D5) for 200h simulating 10 years of operation in an indoor environment.Long-term drift Ethanol signalmeasuredLong-term drift H2 signalFigure 5Typical and maximum long-term drift in % of measuredvalue at 25°C, 50% RH and typical VDD. The sensors have beenoperated for at least 60h before the first characterization.Figure 6 Simplified version of the functional block diagram (compare Figure 1) showing the signalpaths of the SGP30.1.3Recommended Operating ConditionsThe sensor shows best performance when operated within recommended normal temperature and humidity range of5 – 55 °C and 4 –20 g/m3, respectively. Long-term exposure (operated and not operated) to conditions outside therecommended range, especially at high humidity, may affect the sensor performance. Prolonged exposure to extreme conditions may accelerate aging. To ensure stable operation of the gas sensor, the conditions described in the document SGP Handling and Assembly Instructions regarding exposure to exceptionally high concentrations of some organic or inorganic compounds have to be met, particularly during operation. Please also refer to the Design-in Guide for optimal integration of the SGP30.2Electrical Specifications6 A 20% higher current is drawn during 5ms on V DDH after entering the measurement mode.Table 5 Absolute minimum and maximum ratings.Please contact Sensirion for storage, handling and assembly instructions.7 If VDD and VDDH are not shorted, it is required that VDD is always powered when VDDH is powered. Otherwise, the sensor might be damaged.85 Timing Specifications5.1 Sensor System TimingsThe timings refer to the power up and reset of the ASIC part and do not reflect the usefulness of the readings.Parameter Symbol ConditionMin. Typ. Max. Unit Comments Power-up time t PU After hard reset, V DD ≥V POR - 0.4 0.6 ms - Soft reset timet SRAfter soft reset-0.40.6ms-Table 6 System timing specifications.5.2 Communication TimingsParameter Symbol Conditions Min. Typ. Max. Units Comments SCL clock frequencyf SCL-- 400 kHz - Hold time (repeated) START conditiont HD;STA After this period, the first clock pulse is generated 0.6 --µs-LOW period of the SCL clock t LOW - 1.3 - - µs - HIGH period of the SCL clockt HIGH- 0.6 - - µs - Set-up time for a repeated START condition t SU;STA - 0.6 - - µs - SDA hold time t HD;DAT - 0 - - ns - SDA set-up time t SU;DAT - 100 - - ns - SCL/SDA rise time t R - - - 300 ns - SCL/SDA fall time t F - - - 300 ns - SDA valid timet VD;DAT - - - 0.9 µs - Set-up time for STOP condition t SU;STO - 0.6 - - µs - Capacitive load on bus lineC B-400pF-Table 7 Communication timing specifications.Figure 8 Timing diagram for digital input/output pads. SDA directions are seen from the sensor. Bold SDA lines are controlled by the sensor; plain SDA lines are controlled by the micro-controller. Note that SDA valid read time is triggered by falling edge of preceding toggle.SCL70% 30%t LOW1/f SCL t HIGHt Rt FSDA70% 30%t SU;DATt HD;DATDATA INt RSDA70% 30% DATA OUTt VD;DATt F6Operation and CommunicationThe SGP30 supports I2C fast mode. For detailed information on the I2C protocol, refer to NXP I2C-bus specification8. All SGP30 commands and data are mapped to a 16-bit address space. Additionally, data and commands are protected with a CRC checksum to increase the communication reliability. The 16-bit commands that are sent to the sensor already include a 3-bit CRC checksum. Data sent from and received by the sensor is always succeeded by an 8-bit CRC.In write direction it is mandatory to transmit the checksum, since the SGP30 only accepts data if it is followed by the correct checksum. In read direction it is up to the master to decide if it wants to read and process the checksum.The I2C master can abort the read transfer with a XCK followed by a STOP condition after any data byte if it is not interested in subsequent data, e.g. the CRC byte or following data bytes, in order to save time. Note that the data cannot be read more than once, and access to data beyond the specified amount will return a pattern of 1s.6.3Measurement CommandsThe available measurement commands of the SGP30 are listed in Table 10.Air Quality SignalsThe SGP30 uses a dynamic baseline compensation algorithm and on-chip calibration parameters to provide two complementary air quality signals. Based on the sensor signals a total VOC signal (TVOC) and a CO 2 equivalent signal (CO 2eq) are calculated. Sending an “Init_air_quality” command starts the air quality measurement. After the “Init_air_quality” command, a “Measure_air_quality” command has to be se nt in regular intervals of 1s to ensure proper operation of the dynamic baseline compensation algorithm. The sensor responds with 2 data bytes (MSB first) and 1 CRC byte for each of the two preprocessed air quality signals in the order CO 2eq (ppm) and TVOC (ppb). For the first 15s after the “Init_air_quality” command the sensor is in an initialization phase during which a “Measure_air_quality” command returns fixed values of 400 ppm CO 2eq and 0 ppb TVOC.The SGP30 also provides the possibility to read and write the baseline values of the baseline correction algorithm. This feature is used to save the baseline in regular intervals on an external non-volatile memory and restore it after a new power-up or soft reset of the sensor. The command “Get_baseline” ret urns the baseline values for the two air quality signals. The sensor responds with 2 data bytes (MSB first) and 1 CRC byte for each of the two values in the order CO 2eq and TVOC. These two values should be stored on an external memory. After a power-up or soft reset, the baseline of the baseline correction algorithm can be restored by sending first an “Init_air_quality” command followed by a “Set_baseline” command with the two baseline values as parameters in the order as (TVOC, CO 2eq). An example implementation of a generic driver for the baseline algorithm can be found in the document SGP30_driver_integration_guide .A new “Init_air_quality” command has to be sent after every power -up or soft reset.Sensor Raw SignalsThe command “Measure_raw_signals” is i ntended for part verification and testing purposes. It returns the sensor raw signals which are used as inputs for the on-chip calibration and baseline compensation algorithms as shown in Figure 6. The command performs a measurement to which the sensor responds with 2 data bytes (MSB first) and 1 CRC byte (see Figure 9) for 2 sensor raw signals in the order H2_signal (s out_H2) and Ethanol_signal (s out_EthOH ). Both signals can be used to calculate gas concentrations c relative to a reference concentration c ref byln (c c ref ⁄)=s ref −s outawith a = 512, s ref the H2_signal or Ethanol_signal output at the reference concentration, and s out = s out_H2 or s out = s out_EthOH .Humidity CompensationThe SGP30 features an on-chip humidity compensation for the air quality signals (CO 2eq and TVOC) and sensor raw signals (H2-signal and Ethanol_signal). To use the on-chip humidity compensation an absolute humidity value from an external humidity sensor like the SHTxx is required. Using the “Set_humidity” comm and, a new humidity value can be written to the SGP30 by sending 2 data bytes (MSB first) and 1 CRC byte. The 2 data bytes represent humidity values as a fixed-point 8.8bit number with a minimum value of 0x0001 (=1/256 g/m 3) and a maximum value of 0xFFFF (255 g/m 3 + 255/256 g/m 3). For instance, sending a value of 0x0F80 corresponds to a humidity value of 16.50 g/m 3 (16 g/m 3 + 128/256 g/m 3).After setting a new humidity value, this value will be used by the on-chip humidity compensation algorithm until a new humidity value is set using the “Set_humidity” command. Restarting the sensor (power-on or soft reset) or sending a value of 0x0000 (= 0 g/m 3) sets the humidity value used for compensation to its default value (0x0B92 = 11.57 g/m 3) until a new humidity value is sent. Sending a humidity value of 0x0000 can therefore be used to turn off the humidity compensation.Feature SetThe SGP30 features a versioning system for the available set of measurement commands and on-chip algorithms. This so called feature se t version number can be read out by sending a “Get_feature_set_version ” command. The sensor responds with 2 data bytes (MSB first) and 1 CRC byte (see Table 9). This feature set version number is used to refer to a corresponding set of available measurement commands as listed in Table 10.Table 9 Structure of the SGP feature set number. Please note that the last 5 bits of the product version (bits 12-16 of the LSB) are subject to change. This is used to track new features added to the SGP multi-pixel platform.Measure TestThe command “Measure_test” which is included for integration and production line testing runs an on-chip self-test. In case of a successful self-test the sensor returns the fixed data pattern 0xD400 (with correct CRC).9 The «Measure_Test» command is intended for production line testing and verification only. It should not be used after having issued an “Init_air_quality” command. For the duration of the «Measure_Test» command, the sensor is operated in measurement mode with a supply current as specified in Table 3. After the command, the sensor is in sleep mode.Table 13 I2C CRC properties.6.7Communication Data SequencesFigure 10 Laser marking on SGP30. The pin-1 location is indicated by the keyhole pattern in the light-colored central area. The bottom line contains a 4-digit alphanumeric tracking code8.3Package OutlineFigure 12 Recommended landing pattern.9Tape & Reel Package11Important Notices11.1Warning, Personal InjuryDo not use this product as safety or emergency stop devices or in any other application where failure of the product could result in personal injury. Do not use this product for applications other than its intended and authorized use. Before installing, handling, using or servicing this product, please consult the data sheet and application notes. Failure to comply with these instructions could result in death or serious injury. If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application, Buyer shall defend, indemnify and hold harmless SENSIRION and its officers, employees, subsidiaries, affiliates and distributors against all claims, costs, damages and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if SENSIRION shall be allegedly negligent with respect to the design or the manufacture of the product.11.2ESD PrecautionsThe inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD-induced damage and/or degradation, take customary and statutory ESD precautions when handling this product.See application note “ESD, Latchup and EMC” for more information.11.3WarrantySENSIRION warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of delivery that this product shall be of the quality, material and workmanship defined in SENSIRION’s published specifications of the product. Within such period, if proven to be defective, SENSIRION shall repair and/or replace this product, in SENSIRION’s discretion, free of charge to the Buyer, provided that:∙notice in writing describing the defects shall be given to SENSIRION within fourteen (14) days after their appearance;∙such defects shall be fou nd, to SENSIRION’s reasonable satisfaction, to have arisen from SENSIRION’s faulty design, material, or workmanship;∙the defective product shall be returned to SENSIRION’s factory at the Buyer’s expense; and∙the warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period.This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by SENSIRION for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN, SENSIRION MAKES NO WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED. SENSIRION is only liable for defects of this product arising under the conditions of operation provided for in the data sheet and proper use of the goods. SENSIRION explicitly disclaims all warranties, express or implied, for any period during which the goods are operated or stored not in accordance with the technical specifications.SENSIRION does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. All operating parameters, including without limitation recommended parameters, must be validated for each customer’s applications by customer’s technical experts. R ecommended parameters can and do vary in different applications. SENSIRION reserves the right, without further notice, (i) to change the product specifications and/or the information in this document and (ii) to improve reliability, functions and design of this product.Copyright© 2017 by SENSIRION.CMOSens® is a trademark of Sensirion.All rights reserved.12Headquarters and SubsidiariesSensirion AG Laubisruetistr. 50CH-8712 Staefa ZH Switzerlandphone: +41 44 306 40 00 fax: +41 44 306 40 30 ****************** Sensirion Inc., USAphone: +1 312 690 5858*********************Sensirion Korea Co. Ltd.phone: +82 31 337 7700~3*********************www.sensirion.co.kr Sensirion Japan Co. Ltd.phone: +81 3 3444 4940*********************www.sensirion.co.jpSensirion China Co. Ltd.phone: +86 755 8252 1501*********************Sensirion Taiwan Co. Ltdphone: +886 3 5506701****************** To find your local representative, please visit /distributors。

CHINAPLAS 2013 彰显国际大展风采

塑料制造3年6月刊C HINAPL AS 2013彰显国际大展风采本刊记者/楚念良杨清有着亚洲第一、全球第二美誉的第27届中国国际塑料橡胶工业展览会(C H IN A P LA S2013国际橡塑展)于5月20日至23日在广州市琶洲中国进出口商品交易会展馆隆重举行，这届展会，成为全世界制造业展示前瞻性强、着重持续发展并融合橡塑应用及创新科技的商贸平台。

为期4天的展会吸引超过115000名中外专业买家到场，观摩、采购最新化工原材料及各式橡塑机械、精密模具和技术。

这届展会，来自全球38个国家及地区的3000家展商，展示超过3200台机械及最新橡塑化工及原材料，比2012年展出的机械增加28%。

此外，展会获得15个国家及地区组织展团支持，包括奥地利、加拿大、法国、德国、意大利、日本、韩国、中国、中国台湾、中国香港、新加坡、瑞士、土耳其、英国及美国等展团。

先进设备、精密模具及材料的竞技场这届展会，无疑是先进设备与技术厂商的竞技场。

3.2与4.2馆特设了模具及加工设备专区，重点企业及品牌有：伊之密、力劲、震雄，力劲集团、巴顿菲尔辛辛那提、雅琪集团、香港模具协会、南京科锐、精英制模、鸿利达模具有限公司、富强鑫精密工业股份有限公司、龙记集团、广州数控、南烽精密机械(深圳）有限公司、双叶电子工业株式会社、宁波海太工贸有限公司、银禧工程塑料（东莞）有限公司、丰铁塑机(广州)有限公司、日本制钢所塑料机(香港)有限公司。

蔡司、英柯欧模具（上海）有限公司、广东联升精密机械制造有限公司、东莞市保科热流道科技有限公司、哈斯高贸易（深圳）有限公司、深圳市欣天锐电子科技有限公司、兰州兰泰塑料机械有限公司、江阴米拉克龙机械有限公司、凯迈（洛阳）机电有限公司、博创机械股份有限公司、承德市金建检测仪器有限公司、福建东南新材料股份有限公司、仁兴机器厂有限公司、上海金湖挤出设备有限公司等。

让我们一起走进C H IN A PLA S2013，感受展会的精彩——www.c n-p lastic s.n et 20122SA B I C——“筑光概念房”圆“中国梦”沙特基础工业公司(S A B IC)在C hi naplas2013国际橡塑展上隆重展出“筑光概念房”(A rchi-L i ght C oncept H ouse)。

2013年世界科技发展回顾——新材料

项金属特性实验中发现金属具有自我修复的功能，这一发
现为设计出可自我复原合材料，或许有望成为首个
在计算机运行温度范围内导电效率达到１００％的材料，代替
硅制造速度更快耗能更低的计算机芯片。
了一种新型纳米涂层材料，用这种材料涂在纱网或织物表面，可形成一种对液体的弹力，能排斥上百种液体，不仅抗污染能力极强，而且保护穿着者免受化学药品伤害。哈佛大学等开发出一种结构独特的新纤维，能在拉伸时改变颜色，色彩可覆盖整个可见光谱的范围。由于其柔韧有弹性，因此可
碳纳米管组成的碳制导线，其强度是铜导线的３０倍，重量不
作为一种智能材料感知热和压力，还可作为新型体育纺织
品，在肌肉紧张程度不同的部位显出不同颜色。北卡罗来纳
到铜线的十分之一，未来有望成为铜线的有力竞争对手；同
纳米纤维，比头发细千倍却比钢坚硬１５倍，堪称世界上最高
强度、最轻的“ 纳米线 ” ，它的出现可能会改变未来整个世界的复合材料和这些材料的高强度，将对海洋、航空和安全等
行业产生巨大影响；７月，剑桥大学科学家开发出一种由许多
２０
其
他
赣
美国
｜
＿
材料，该新材料可以像眼泪那样具有显著光学功能且保持清
在无机非金属材料、高分子材料以及生物医用材料等多
晰的透视度，同时保持眼睛湿润，免受灰尘和细菌污染。能

糖尿病并肺结核临床特点

下肺野病变高于单纯肺结核者，空洞形成较单纯肺结核者常见，空洞内可出现液平，而且下肺病灶和空洞随年龄的增加占的比例越高。
糖尿病并肺结核影像学特点
营养不良发生率高
糖尿病并结核、糖尿病、结核病及健康对照各60例营养不良状况
项目 TB&DM
BMI 33(55.0%) HB 36(60.0%)
DM
33(55.0%) 27(45.0%)
痰菌阳性率高
北京胸科医院（2011年1月～12月）
糖尿病并肺结核组395例：单纯肺结核组221例：
平均年龄：岁
平均年龄：岁
菌阳病例：330例（83.5%）菌阳病例：123例（55.7%）
2012年中华医学会结核病分会学术大会论文汇编
下肺病灶多见
胸部X线表现多以浸润、渗出、干酪样病变为主，且易于融合、空洞形成、支气管播散，病灶部位不一定是结核病常见好发部位，各肺叶均可见；
7
糖尿病对结核病治疗的影响
增加结核病死亡风险
合并糖尿病与不合并糖尿病的结核病患者比较，23项研究表明糖尿病增加了结核病的死亡率
相对危险度（RR） = 1.85 (95% CI, 1.5 – 2.3) 4项研究对年龄及其他混淆因素进行了校正，OR=
4.95 (95% CI, 2.7 – 9.1)
8/69 (11.6%) 10/68 (14.7%)
Blanco (2007)
Canary Is lands ,Spain 4/13 (30.8%) 13/85 (15.3%)
Guler (2007)*
Turkey
32/44 (72.7%) 88/262 (33.6%)
Dooley (2009)
USA
9/30 (30%)

小米手机电机说明书

Mini Vibration Motor Operating conditionsMechanical specificationsPerformance and characteristicsCaution and Matters8-1 Warnings: In a motor near the end its life, or under breakdown conditions, short circuits can develop between commutator segments. Uncontrolled voltage may then leak into the power source circuit. Motors may overheat or fail if run continuously with its rotor locked condition or under excessive loads.8-2 Destructive atmospheres: Do not use and store the motor in the corrosive gas atmosphere (H2S, SO2, NO2, Cl2, etc.), or substances that can emit toxic gases, such as organic silicon, cyanide, formalin, or phenol compounds. The motor may get serious damages.8-3 Condensation: Condensation on the electrical circuits can destroy the motor or control circuits. Monitor the environment and undertake measures to prevent condensation, such as installing condensation sensors to cut power when necessary.8-4 Be aware of the following factors and perform necessary tests to check a motor capability to adopt with your mechanism and applications: Motor life, electric noise, mechanical noise, vibration, static-electrical noise resistance, power-source noise resistance, drift of rpm, electrical resonance between control circuit and motor, mechanical resonance between subassembly and motor malfunction due to motor noise, electrical magnetic interference, malfunction due to magnetic flux leakage, destruction due to lightning-related power surge, grounding.8-5 Some particular plastic materials can crack and fail after exposure to motor bearing oil. Perform test the motor in/on the subassembly to check the influence of the oiled plastic parts.8-6 Avoid connecting a serial resistor to the motor if at all possible, as this can negatively affect reliability. If this is unavoidable, keep resistance as low as possible and test thoroughly for reliability before using.8-7 When testing for UL, CSA or other safely standards, apply for approval for the entire subassembly.8-8 Do not store motors under conditions of extreme temperatures or high humidity, or for longer than six months even room conditions. When removing out of packaging after storage, take precautions to prevent condensation.8-9 Connections: Complete soldering operations within three seconds to prevent damage to leads and terminals. Make sure that the soldering tip does not exceed 350c. Be gentle with terminals; dents or pressure on them can lock up the motor.8-10 Please consults us in advance when design considerations call for forcefully stalling the motor using a short circuit at the terminal or reverse voltage. Such operations can shorten product life.。

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Global tire evolution ongoing, says Tire Business
03 October 2013
ERJ staff report (TB)
Akron, Ohio – The anniversary of Bridgestone Corp.'s purchase 25 years ago of Firestone Tire & Rubber Co. is a reminder that the global tire industry continues to evolve and that more changes in tire company ownership and leadership are likely to continue, according to an editorial in ERJ’s sister publication Tire Business.
Consider two current happenings – Apollo Tyres Ltd.'s bid to acquire Findlay, Ohio-based Cooper Tire & Rubber Co., and plans by China's GITI Tire Pte. Ltd. to set up technical centres in Akron and Hannover, Germany.
Regarding the latter, GITI would become the first Chinese tire maker to establish a technical centre in the U.S. Another Chinese tire maker, Triangle Group Co. Ltd., announced in 2011 it would establish a research, development and sales company, also in Akron, but its operating status is unclear.
A quarter of a century ago, foreign tire companies were on a buying binge, scooping up U.S. tire manufacturers to gain a foothold in this country and to expand their production capabilities globally.
Those deals included Continental A.G.'s acquisition of General Tire & Rubber Co., Pirelli & C. S.p.A.'s purchase of Armstrong Rubber Co., Group Michelin's takeover of Uniroyal Goodrich Tire Co., Yokohama Rubber Co. Ltd.'s buying Mohawk Rubber Co., and the granddaddy of them all, Bridgestone's purchase of Firestone.
When the dust finally settled, only Goodyear and Cooper remained among the top echelon of the world's largest tire makers with headquarters in the US
Gurgaon, India-based Apollo's proposed acquisition of Cooper is just the latest attempt by a foreign tire company to acquire a U.S. firm and leapfrog into the Top 10 ranking of global tire makers.
At the same time, we are witnessing the beginnings of Chinese tire companies expanding their manufacturing and technical bases beyond their home country.
Although GITI's move to establish technical centers in two of the world's largest tire markets outside of Asia doesn't involve manufacturing – at least not yet – it's an indicator that the company is seeking to design tires tailored for these specific markets. If this effort proves successful, other Chinese tire manufacturers are likely to follow, so as not to be left behind.
Bridgestone's surprising bid for Firestone a quarter century ago ultimately propelled it to become the world's largest tire manufacturer. It will be interesting to see what the next 25 years brings.。