Searching high gray scale FPD scanning matrix based on PSO

With the increase of gray scale and flat panel display （FPD） size, subspace bitwise scanning strategy can be replaced traditional scanning method to cut down frame frequency. However, the direct searching strategy （DSS） becomes unfeasible to obtain corresponding high gray scale scanning matrix. Thus, particle swarm optimization （PSO） is introduced to accelerate searching for high gray scale weights scanning matrix （WSM） with its parallelism and global optimization feature. Finally a WSM of 256 gray scales is found out successfully with Matlab, which both gray linearity and scanning efficiency are satisfied.

Optimal strategy of searching FPD weights scanning matrix using GA-PSO

This paper discusses a kind of optimal method used for searching flat panel display （FPD） scanning matrix. The method adopts bionic algorithm： genetic algorithm （GA） and particle swarm optimization （PSO） algorithm. The method using single GA is more time-consuming, and the search efficiency is low in later evolution; the PSO algorithm is easily falling into the local optimal solution and appears the premature convergent phenomenon. Hence, a hybrid approach of GAPSO is found to optimize the search for high grayscale weights scanning matrix. Finally in the acceptable time, it finds a weight scanning matrix （WSM） of 256 gray scales with Matlab, whose scanning efficiency reaches 94.73% and the linearity is very good.

Detecting Impact Damage in Carbon Fabric/epoxy-matrix Composites by Ultrasonic F-scan and Electrical Resistance Measurement

The status and the variation of electrical resistance of impacted carbon fiber/epoxy-matrix composites were studied by ultrasonic F-scan and electrical resistance measurement The experimental results shows that impact damage energy threshold value of carbon fabric/epoxy-matrix composites can determine by using ultrasonic F-scan. When the impact energy exceeds the threshold value, damage is generated in composites. Electrical resistance of impacted composites is changed owing to the contact of each carbon fiber unit in composites, which cause a change of the series-parallel in conductors. The veracity of detecting impact damage in composites can be improved in this case.

隧道三维电阻率E-SCAN超前探测反演与优化方法研究

超前地质预报是隧道施工中必不可少的环节,将地面三维电阻率E-SCAN观测模式引入到隧道超前预报中,其中供电与采集电极都布置在隧道掌子面,可有效降低旁侧干扰因素的影响,提出了基于三维电阻率E-SCAN的隧道超前探测新型观测模式。建立了隧道三维电阻率E-SCAN超前探测地电模型,获得了敏感度矩阵分布特征:矩阵元素数值较小且相差悬殊;元素绝对值随深度衰减迅速;靠近供电与采集电极位置元素绝对值较高。为改善反演的深度定位问题,对敏感度矩阵中元素施加不同大小的增益因子,对原有敏感度矩阵中高值元素进行抑制,对低值元素进行增益,形成了基于敏感度增益因子的隧道三维电阻率E-SCAN超前探测反演优化方法,在理论上可以提高异常体的深度定位精度。开展数值算例与物理模型试验研究,结果表明在隧道三维电阻率E-SCAN超前探测中,相较于常规光滑约束反演,反演优化方法在异常体的深度定位精度方面具有明显优势。

玻璃纤维增强不饱和聚酯树脂防火隔板湿热老化特性

为了研究玻璃纤维增强不饱和聚酯树脂防火隔板湿热老化特性,结合电缆隧道内实际温湿环境和加速老化模型对防火隔板进行等效湿热老化处理。通过扫描电镜试验、热重试验、氧指数试验以及冲击强度试验检测了试样的微观形貌、热稳定性、燃烧性能和机械性能。结果表明,老化1周期后试样表面析出白色粉状物、老化3周期后断面出现明显裂痕;微观形貌图显示老化2周期后试样中的树脂从玻璃纤维上脱落,老化5周期后大量玻璃纤维裸露在外。试样质量损失率峰值最终升高45%,冲击强度最终下降41.6%,抗弯强度最终降低47.3%,吸水抗弯强度最终下降42.5%,表明湿热老化后试样热稳定性及机械性能出现明显下降。试样氧指数最终提高28.7%;烟密度等级均满足技术规范标准。上述两项检测无法作为判断湿热老化后防火隔板性能劣化的指标。

数字化辅助一体化纤维桩核及树脂基陶瓷冠修复冠折年轻恒牙1例

桩核修复是临床常见的牙体缺损修复方式,临床常用桩核主要有玻璃纤维预成桩树脂核和个性化一体式桩核。在个性化桩核的材料选择上,由于金属的美观缺陷及氧化锆的弹性模量限制,兼具个性化、机械性能及美学优势的一体化玻璃纤维桩核作为一种新型桩核形式被临床所应用。本文报告1例CAD/CAM一体化纤维树脂桩核及树脂基陶瓷冠修复年轻恒牙冠折的临床病例。

掺黏粒改良粉土的土水特征试验研究

以河南开封金明大道北延道路路基工程低液限粉土为研究对象,通过滤纸法测定不同黏粒含量、压实度的粉土土水特征曲线,研究其基质吸力变化规律;采用扫描电镜试验从微观结构演化角度分析其影响机制。结果表明:加州承载比CBR值随黏粒含量与压实度的增加均单调增大;不同压实度下掺黏粒改良粉土的饱和含水率均随黏粒含量的增加呈先增大后减小趋势;任一黏粒含量下,土水特征曲线具有明显的阶段性特征,黏粒含量为15.5%、20.5%、26.5%的土水特征曲线存在基质吸力保持相对恒定的平台期;黏粒含量的增加使得重塑土样的微观结构逐渐紧密,粉黏粒间的接触方式由线或面的接触逐渐转变为胶结及包裹镶嵌作用。根据规范要求,掺黏粒改良粉土可应用于公路路基填筑。

DSC analysis of Al_2O_3-SiO_2 short fiber reinforced Al-Cu-Mg alloy matrix composites

AlO-SiOshort fiber/Al-Cu-Mg matrix composites containing different Mg contents were fabricated using squeeze casting method.Differential scanning calorimeter(DSC) was used to investigate the reaction condition of the composites with different Mg contents.The microstructure of the composites was observed by transmission electron microscopy(TEM).The experimental results show that the Mg content added to the 2024Al matrix significantly affects interfacial condition between Al2O3-SiO2 short fiber and aluminum matrix.At the temperature above 538 ℃,Al2O3-SiO2 short fiber is prone to react with Mg and forms MgAl2O4 reaction product when Mg content added to aluminum matrix is above 1.0wt%.

EFFECT OF REINFORCEMENT VOLUME FRACTION ON PRECIPITATION IN MATRIX OF SiC_p/AI COMPOSITE

The differential scanning calorimetric(DSC) and transmission electron microanalysis (TEM) techniques were used to study the kinetic process of precipitation in matrix of cast SiC_p/2024 composites.The results showed that precipitation reactions of GP zone and intermediate phase S'(Al_2CuMg)in the composites were accelerated compared with SiC-free material,the peak temperatures of both reactions were decreased.The reaction enthalpies of both the GP zone and intermediate phase S' formation in the matrix were substantially decreased after the addition of SiC.TEM analysis found that the alloying element Mg segregated at the SiC/Al interfaces,and was depleted in the matrix near the interface.The precipitation-free zones(PFZ) and precipitation-sparse zones(PSZ) formed near the interfaces,as a results,the volume fraction of precipitates in matrix was reduced.

Identification of Growth Promoter to Fabrication SiCp/Al₂O₃Ceramic Matrix Composites Prepared by Directed Metal Oxidation of An Al Alloy

SiC particulates reinforced alumina matrix composites were fabricated using Directed Metal Oxidation (DIMOX) process. Continuous oxidation of an Al-Si-Mg-Zn alloy with different interlayers (dopents) as growth promoters, will encompasses the early heating of the alloy ingot, melting and continued heating to temperature in the narrow range of 950°C to 980°C in an atmosphere of oxygen. Varying interlayers (dopents) are incorporated to examine the growth conditions of the composite materials and to identification of suitable growth promoter. The process is extremely difficult because molten aluminum does not oxidize after prolonged duration at high temperatures due to the formation of a passivating oxide layer. It is known that the Lanxide Corporation had used a combination of dopents to cause the growth of alumina from molten metal. This growth was directed, i.e. the growth is allowed only in the required direction and restricted in the other directions. The react nature of the dopants was a trade secret. Though it is roughly known that Mg and Si in the Al melt can aid growth, additional dopents used, the temperatures at which the process was carried out, the experimental configurations that aided directed growth were not precisely known. In this paper we have evaluated the conditions in which composites can be grown in large enough sizes for evaluation application and have arrived at a procedure that enables the fabrication of large composite samples by determining the suitable growth promoter (dopant). Scanning electron microscopic, EDS analysis of the composite was found to contain a continuous network of Al2O3, which was predominantly free of grain-boundary phases, a continuous network of Al alloy. Fabrication of large enough samples was done only by the inventor company and the property measurements by the company were confirmed to those needed to enable immediate applications. Since there are a large number of variable affecting robust growth of the composite, fabrication large sized samples for measurements is a difficult task. In the present work, to identify a suitable window of parameters that enables robust growth of the composite has been attempted.

Reaction Processes of the Titanium Matrix Composites Fabricated from Ti-Al-B2O3 System

Titanium matrix composites reinforced with a-Al2O3 and TiB2 particles were fabricated by in situ synthesis from a Ti-Al-B2O3 system. The reaction processes and microstructure were analyzed by using differential scanning calorimetry（DSC）, scanning electron microscopy（SEM） and X-ray diffraction（XRD）. The results showed that the reactions in the Ti-Al-B2O3 system can occur spontaneously and consist of three steps： 1） 15 Al ＋ 7B2O3 → 7α-Al2O3 ＋ AlB12 ＋ 2B; 2） 14 B ＋ 2Al → AlB12 ＋ AlB2 and 3） 7Ti ＋ AlB（12） ＋ AlB2 → 7TiB2 ＋ 2Al. The final reinforcements were composed of α-Al2O3 and TiB2 particles, which were uniformly distributed in the titanium matrix.

Prediction of the Elastic Properties of Short Basalt Fiber Reinforced Al Alloy Metal Matrix Composites

In this paper, a micro-mechanical model is implemented in software for the prediction of local mechanical properties of discontinuous short fiber reinforced composites. The model, based on the Mori and Tanaka method, shear-lag, computational model, Nielsen-Chen model and Miwa’s model is used to predict the elastic behaviour of basalt short fiber reinforced with Al alloy composites. The Al/basalt Metal Matrix Composites (MMCs) contain basalt short fiber from 2.5% to 10% in steps of 2.5 wt.% and are fabricated using squeeze infiltration technique. The effects of fiber length and orientation on elastic properties of Al/basalt MMCs are investigated. A comparison between the experimental data and the theoretical data based on physical models is made, and the significance of the findings is discussed. The results show that as short basalt fiber content was increased from 2.5% to 10% by wt.%, an improvement in Young’s modulus of 13.26% has been observed. Optical microscopy was used to examine the general microstructure and fiber distribution in the composite produced. Scanning Electron Microscopy (SEM) was performed on the fractured surface to understand the failure mechanisms.

利用波长慢速扫描和快速调制激光吸收光谱实验数据反演光谱吸收函数的理论和实验研究

在波长慢速均匀扫描和波长快速周期调制的情况下,基于激光吸收光谱的实验数据,提出了利用激光调制频率和激光扫描范围两个参数以及透射波信号和参考波信号反演谱线吸收函数的矩阵切片方法.当波长调制为单频正弦调制时,利用透射波信号和参考波信号的相除结果得到的矩阵,通过两个相距半个调制周期的切片积分的最小值即可得到准确的谱线吸收函数轮廓,并能反演出调制幅度的大小.当波长的快速调制扭曲为非单频的多频叠加调制时,可以利用多个切片的互补形成谱线吸收函数.上述方法可以用于在扫描波长范围内包含由多条吸收谱线且有重叠的真实吸收函数反演过程.而且,可以利用扫描波长范围内多条谱线的间隔参数来标定激光波长的扫描范围.采用上述的矩阵切片法,通过实验验证,得到了低吸收状况下CO在4300.700 cm^(-1)吸收谱线的吸收函数和较强吸收状况下CO_(2)在6336 cm^(-1)附近2条吸收谱线的吸收函数信息.

多点扫描矩阵激光联合康柏西普治疗重度非增殖型糖尿病视网膜病变的临床效果观察

目的观察多点扫描矩阵激光联合康柏西普治疗重度非增殖型糖尿病视网膜病变的临床疗效。方法选取2019年1月—2022年1月河北省眼科医院诊治的重度非增殖型糖尿病视网膜病变患者76例,随机分为对照组(38例,康柏西普治疗)和联合组(38例,康柏西普联合多点扫描矩阵激光治疗)。比较治疗前,治疗后1个月、3个月、6个月后两组最佳矫正视力(BCVA)字符提高数、黄斑中心凹厚度(CMT);比较两组的临床疗效和不良反应。结果两组治疗前,治疗后1个月、3个月、6个月的BCVA字符提高数及CMT比较,结果:(1)不同时间点的BCVA字符提高数、CMT有差异(P<0.05);(2)两组的BCVA字符提高数、CMT有差异(P<0.05),联合组与对照组相比BCVA字母提高数比较多,相对视力改善效果较好,CMT比较低,相对黄斑区改善效果较好;(3)两组的BCVA字符提高数、CMT变化趋势有差别(P<0.05)。两组总有效率比较,差异有统计学意义(P<0.05),联合组高于对照组。两组随访期间均未发生与治疗相关的严重不良反应。联合组注射后一过性眼压升高及局部球结膜下出血各1例,未处理即在1周内恢复正常。结论多点扫描矩阵激光联合康柏西普可改善重度非增殖型糖尿病视网膜病变视力及黄斑水肿,提高临床疗效,且安全可靠。

低剂量CT扫描结合CD147、TK1水平检验在肺小结节良恶性鉴别中的应用价值

目的分析不同性质肺小结节低剂量CT扫描参数和实验室指标细胞外基质金属蛋白酶诱导因子CD147、胸苷激酶1(TK1)水平差异,并评价各指标对肺小结节良恶性的鉴别诊断价值。方法回顾性选取2020年1月至2022年1月在秦皇岛市第一医院接受检查并经病理诊断的147例肺小结节患者为研究对象,以病理活检结果作为金标准,将患者分为良性组(n=105)和恶性组(n=42)。患者均接受低剂量CT平扫和增强扫描,收集扫描CT值和实验室指标CD147、TK1,绘制受试者工作特征(ROC)曲线,评估分析低剂量CT值和CD147、TK1对肺小结节良恶性的鉴别价值。结果低剂量CT检出恶性49例,良性98例,对恶性肺小结节诊断敏感度、特异度、准确度分别为90.48%(38/42)、89.52%(94/105)、89.80%(132/147)。影像学中,良性结节边缘清晰,内部以钙化为主;恶性结节为边缘不规则或分叶征、毛刺为主,内部多为均匀征;良性组动态增强CT值及实验室指标CD147、TK1水平均明显低于恶性组,差异均有统计学意义(P<0.05)。ROC诊断模型中,低剂量CT诊断结果结合CD147、TK1具有极高准确性,其诊断AUC、约登指数、敏感度、特异度分别为0.940、0.862、92.90%、93.30%。结论恶性肺小结节血清CD147、TK1水平明显升高,预示肿瘤细胞异常活动。低剂量CT和实验室指标CD147、TK1均对肺小结节性质筛查具有重要应用价值,二者联合诊断,可以提高肺小结节良恶性的诊断效能。

基于灰度共生矩阵和工业CT扫描的受载含瓦斯煤裂隙动态演化特征

为研究受载含瓦斯煤在三轴压缩作用下的裂隙演化规律,利用受载含瓦斯煤显微工业CT扫描系统,开展了三轴加载条件下受载含瓦斯煤的工业CT扫描测试,获取了受载含瓦斯煤的应力-应变曲线和各变形阶段的CT扫描图形.运用图像分析软件对CT扫描数据进行了三维数字重建,实现了煤样内部裂隙的三维可视化和定量表征,并基于灰度共生矩阵(GLCM)理论分析了受载含瓦斯煤的裂隙动态扩展特征及规律.研究结果表明:瓦斯压力的存在一定程度上弱化了受载含瓦斯煤的力学性质,同时也加速了裂隙的扩展;受载含瓦斯煤二维裂隙先闭合后扩展,峰后快速扩展并形成连通二维裂隙网络;三维裂隙体积和裂隙密度呈现出先减小后增大的变化趋势,总体上可划分为裂隙压密闭合、新裂隙萌生扩展和主裂隙加速扩展贯通3个变化阶段;灰度共生矩阵分析中,对比度先减小后增大,能量和同质性先增大后减小,相关性呈现出单调递减趋势,准确描述了受载含瓦斯煤内部裂隙随应力增加不断变化的总体发展规律.

应用于RFID群读的多波束扫描天线系统

本文提出一种应用于RFID群读的多波束扫描方案,其基本原理是基于Butler矩阵移相网络理论设计馈电网络,该馈电网络输出端口与各天线单元通过同轴电缆相连,实现各单元天线间信号相位差的调节。由这些天线单元组成的固定间距的直线阵列天线,即可实现射频信号波束方向的偏转,并结合时分复用技术,实现多波束扫描功能。本文给出了馈电网络及天线结构的具体设计,并通过仿真计算发现,该设计方案的各项参数与理论基本一致。

基于三维激光扫描技术的储罐外形高精度复核探讨

本文利用三维激光扫描技术对工业卧式储罐接口的位置和尺寸进行了高精度复核测量。在完成点云拼接和滤波等预处理后,首先,通过提取储罐表面点云进行柱面拟合,得到储罐的主轴线;其次,通过基于总体最小二乘法的平面拟合、基于罗德里格斯(Rodrigues)矩阵的坐标变换以及圆环拟合方法精确获取接口中心的三维坐标;最后,根据轴线和接口坐标计算得到接口的轴向距离、径向距离和方位角。结果显示,利用本文方法测量得到的轴向距离、径向距离和方位角与设计值偏差的均方误差分别为±1.38 mm、±1.70 mm和±0.54°,满足精度要求。

生理通气辅助超高分辨率CT扫描技术探讨

目的：探讨生理通气辅助超高分辨率CT扫描技术（简称G-方案）,提高对肺部局灶性磨玻璃密度灶（f GGO）的细节显示。方法：临床低剂量肺癌筛查中检出的连续20例f GGO患者（男9例,女11例,35~74岁,平均53±11岁）纳入研究,前10例对病灶范围进行常规超高分辨率靶扫描和G-方案扫描,后10例利用筛查原始数据对病灶范围进行回顾性1024矩阵靶重建和G-方案扫描。2位高年资医生共同评价所得图像,评价指标包括：图像细节显示清晰度主观评价、病灶和周围肺野CT值,并进行统计学分析。结果：G-方案扫描图像上磨玻璃灶细节显示清晰度明显优于常规超高分辨率扫描和回顾性重建,病灶所在区域背景肺野CT值明显低于常规超高分辨率扫描（P〈0.05）。病灶与背景之间的密度差（即相对密度值）在各组间没有显著性差异。结论：生理通气辅助帮助背景肺过度充气,结合超高分辨率CT扫描可以增加磨玻璃灶的细节显示能力,进而提高f GGO的诊断准确率。相对密度值可能更适合磨玻璃结节的密度评价。

方阵扫描式自动清洗系统

介绍了方阵扫描式清洗系统。该系统可做成自动式或半自动式。垂直驱动机构、清洗架、垂直行走机构等部件具有互换性。