棉用无醛阻燃剂的合成及其整理工艺

以亚磷酸和乙二醇为反应原料合成了一种羟基磷酸酯型低聚物阻燃剂.该阻燃剂与交联剂丁烷四羧酸和催化剂次亚磷酸钠构成了阻燃整理体系,用于织物整理,得到无甲醛耐久阻燃整理棉织物,合成和应用时不需要特殊的工艺和设备.探讨了阻燃剂用量,交联剂用量,焙烘温度,焙烘时间对阻燃效果的影响.对整理织物的热解质量分析结果表明,该阻燃剂可大大降低棉织物的热裂解温度,阻燃效果具有一定的耐久性,可满足多领域对纺织品的阻燃要求.得到纯棉织物最佳整理工艺:阻燃剂用量400 g/L,交联剂用量80 g/L,焙烘温度180℃,焙烘时间3 min.整理后织物的损毁长度为123 mm,具有较好的阻燃性和耐久性.     

基于RE/RP/RT产品创新设计方法的开发与研究

在传统的产品创新设计方法的基础上,开发出基于RE/RP/RT技术为一体的产品创新设计方法,以适应新产品快速开发与创新设计的需求.此产品设计方法的主要流程是:首先采用RE技术对已有产品(实物)进行测量获得三维坐标数据,并依据设计要求重构得到所需的CAD模型;在将CAD模型离散化后采用RP技术进行快速原型加工;最后以RP制件作为母模,借助RT技术快速制作模具.本文以鼠标产品外形的创新设计为例,进行了基于RE/RP/RT创新设计技术流程的可行性及高效性的验证,实验证明此方法为产品的快速创新设计探索出一条捷径.     

Analytical solution of electromagnetic field generated by induction logging tool in a fan-ring slot of drill collar while drilling

Based on the structural characteristic of metal drill collar for induction logging while drilling, we have given the analytical formulae of lengthways fields E _z and H _z when the tool is located in a fan-ring shaped slot of drill collar by the boundary conditions of electromagnetic field, and derived the other components of electromagnetic field in and out the fan-ring slot from E _z and H _z . In the other intervals of formation, where the drill collar is a solid cylinder, the analytical formulae of field are educed through the method of variable coefficient. The total analytical solutions of field in whole space have been obtained. With the help of the analytical formulae, we have also given numerical examples and analyzed the distributive characteristic of electromagnetic field. From the computational results we find that the secondary scattering field H _z is in a linear relation with the conductivity of stratum. The characteristic of field is very useful for induction logging while drilling, which can be used to measure and analyze the logging responses of the stratum conductivity. This paper sets up a theoretical foundation for us to study the distrbutions of field and to direct the design of logging instruments. Supported by the National Natural Science Foundation of China (Grant No. 10705049), the Beijing Natural Science Foundation (Grant No.1083011) and Funding Project for Academic Human Resources Development in Institutions of Higher Learning [PHR(IHLB)]     

On the design of base-collector junction of InGaAs/InP DHBT

The effects of the composite-collector structure and the δ-doping density in InGaAs/InP DHBT on the Kirk current have been studied.The effective grade layer in the discretely graded layer goes into the InGaAs setback layer.The formulas of the maximum doping density,the maximum Kirk current,and the corresponding δ-doping density are derived under different Kirk-effect conditions.Both the maximum collector doping density and the maximum Kirk current are dependent on the δ-doping layer.By opti-mizing the delta...     

基于视频和人体姿态估计的老年人摔倒监测研究

人口老龄化所带来的养老服务问题是现代社会面临的严重问题。例如在很多国家跌倒是造成老年人因伤致死的最大原因,因此如何对老年人进行自动摔倒监测就成为养老服务亟待解决的问题。目前,在室内摔倒监测领域中,基于可穿戴设备和基于环境传感器等主流摔倒监测方法面临着设备复杂、成本较高等问题。鉴于此,将人体姿态估计引入摔倒监测领域,提出了一种基于2D视频的摔倒监测算法。首先利用OpenPose数据集提取原始数据中人体关节的位置;其次利用这些具有增强特征的数据构建静态分类模型和动态分类模型;最后,在3个公共摔倒数据集上进行模型训练和摔倒监测的测试,取得了较好的效果,可以为摔倒监测相关研究提供一定的参考。     

基于注意力的热点块和显著像素卷积神经网络的人脸防伪方法

人脸防伪用于验证被测试者是否为真实活体,是计算机视觉领域的一个研究热点。攻击手段的多样性以及人脸识别主要在嵌入式、移动式等不具备高计算能力的设备上应用,使得快速有效的人脸防伪计算成为具有挑战性的任务。针对该问题,文中提出了一种基于注意力的热点块和显著像素卷积神经网络的方法。其中,热点块机制以对5个热点块的判别来取代对整张人脸的判别,显著降低了计算量,迫使网络模型集中关注更具有鉴别信息的热点块,提高了网络模型的准确率;显著像素方法对输入的人脸图像进行显著像素预测,通过判断显著预测图是否符合人脸的深度特性来鉴别活体与攻击。该方法将热点块与显著像素的结果进行融合,充分发挥了局部特征和全局特征的作用,进一步提升了人脸防伪的效果。与现有方法相比,所提方法在CASIA-MFSD、Replay-Attack以及SiW数据集上都达到了很好的效果。     

光刻调焦调平测量系统算法比较研究

调焦调平测量系统是光刻机对焦控制的核心部件,调焦调平测量系统的数据处理精度影响光刻机的对焦控制性能,计算速度影响光刻机产能。论文通过仿真与实验对比分析了多项式拟合算法(polynomial fitting)、RF(random forest)算法和XGBoost(extreme gradient boosting)算法在调焦调平测量系统中的测量精度与计算耗时。仿真与实验结果表明,多项式拟合算法精度随时间变化不敏感,RF算法和XGBoost算法精度随计算时间的增加而迅速提升。对于不存在噪声的仿真数据,7阶多项式拟合的3σ值为0.001nm;RF算法在2ms时可对仿真数据完全拟合;XFBoost算法在5ms时,拟合精度基本趋于稳定,为0.6nm。对于存在噪声的实验数据,RF算法与XGBoost算法对噪声有较好的鲁棒性,随计算时间的增加,RF算法与XGBoost算法拟合精度不断提升并分别于3ms和5ms超越多项式拟合算法,但精度提升有限。在光刻机中,为了兼顾对焦精度和产能,必须兼顾算法的拟合精度与拟合时间,因此调焦调平测量系统选用多项式拟合算法较为合适。     

Proton irradiation damage mechanism of the InAlAs／InGaAs／InAlAs quantum well

InP-based high electron mobility transistors (HEMT) have shown a great potential for national defense and satellite radar in space radiation environment applications. This paper studies the proton radiation damage mechanism of its critical structure InAlAs／InGaAs／InAlAs quantum well. The proton projection range and vacancy defect information are obtained at different incident proton energies of 50keV, 75keV and 200keV by SRIM software. With the increase of proton energy, the proton injection depth is increasing and eventually protons pass through the material layers. Besides, the proton radiation induced vacancy defects numbers around hetero-junction increase first and decrease subsequently, and As vacancies are the main proton radiation induced defects. In addition, non-ionizing energy loss (NIEL) of In_0.52Al_0.48As and In_0.53Ga_0.47As material is computed under different incident proton energies by the analytical model. The change trend of NIEL is identical to the induced vacancy numbers, namely, NIEL first increases and then decreases as the incident proton energy increases. Finally the degrading effect of the radiation-induced As defect is detected in the two-dimensional electron gas in the quantum well, which confirms that the major proton radiation damage mechanism of the quantum well is the induced vacancy defects by NIEL.     

SiO2/TiO2共混电纺纤维的制备及光催化性能研究

以正硅酸乙酯(TEOS)和钛酸四丁酯(Ti(OC4H9)4)为原料,采用静电纺丝技术制备了SiO2/TiO2共混纤维膜,经过煅烧后得到了SiO2/TiO2无机纳米纤维.采用TG-DTA对SiO2/TiO2共混无机纤维的热行为进行了表征,并对不同电压、不同纺丝液配比以及不同煅烧温度条件下得到的样品进行了SEM表征,研究不同条件对纤维形貌和光催化性能的影响.结果表明:当纺丝电压+17 kV、接收距离13.5 cm时,纺丝液最佳配比是4.0 g PVP、11 mL EtOH、1.0 mL HAc、1.3 mL TEOS和1.0 mL Ti(OC4H9)4.为了得到形貌和组成兼备的SiO2/TiO2共混无机纤维,确定最佳热处理条件是450℃保温3 h,样品在紫外光照射下对亚甲基蓝的最高去除率达到51%.     

不同缝纫工艺下缝纫阻力的测试与分析

本文采用LM缝纫性测试仪对不同缝纫工艺下的针织物和机织物缝纫阻力进行了测试.测试了织物层数、织物正反面以及缝纫方向不同时,面料缝纫阻力的大小;测试了不同缝针、缝纫线时的缝纫阻力.实验结果表明:织物的缝纫阻力随织物的层数增加而成倍数以上的增大;机织物在45°角左右缝纫时,缝纫阻力最大;针织物在接近纵行和横列方向,缝纫阻力出现最大值;穿引缝纫线会增大缝纫阻力,但缝纫线对缝纫阻力的增大作用较缝针的作用微弱.同时,实验过程中还发现,针织物的缝纫阻力比机织物的不匀率高,缝针刺到纱线上的概率高,因此针织物不易于缝纫.本论文的研究,希望对服装加工给予帮助,以提高服装质量和服装加工效率.