基于改进灰狼优化算法的QFN芯片图像多阈值分割方法

在QFN芯片封装缺陷检测中,增加图像分割环节可有效提高缺陷检测准确性与检测效率。针对图像分割中传统算法效率低、智能优化算法分割精度低稳定性差的问题,本文提出一种基于改进灰狼优化算法(IGWO)的图像多阈值分割方法。首先,改进原始灰狼优化算法非线性因子,平衡算法搜索效率与挖掘能力;其次,引入反向学习策略提高种群整体质量,引入正弦函数、调整头狼权重以改进灰狼更新策略,增强算法多样性与挖掘能力;然后,提出头狼靠拢与种群变异交替进行的位置更新策略,平衡算法收敛性能与跳出局部最优能力;最后,以Kapur熵为适应度函数,求解最优分割阈值。将本文提出的改进灰狼优化算法的多阈值图像分割方法,与灰狼优化算法(GWO)、基于翻筋斗觅食策略的灰狼优化算法(DSF-GWO)、基于莱维飞行的樽海鞘群优化算法(LSSA)、改进北方苍鹰算法(INGO)的图像分割方法进行实验对比,结果表明:本文方法在分割用时方面,约为DSF-GWO的1/2,INGO的1/4;在分割精度与稳定性方面,在进行QFN芯片缺陷图像的连续30次分割时,本文方法具有最大Kapur熵平均值、最小标准差与最短分割时间。因此本文方法可实现高精度、高稳定性与高效率的QFN芯片图像多阈值分割。

酰胺的制备新创实验——N-二苯甲基乙酰胺

以二苯甲醇与乙腈为原料、摩尔比5%碘单质或对甲苯磺酸作为催化剂,加热反应2 h,即可得到~85%分离收率的N-二苯甲基乙酰胺产物。本新创实验基于绿色化学理念,综合了醇的性质、碳正离子理论、BrØnsted与Lewis酸碱理论、Ritter人名反应等基础知识和基本理论,强化了TLC (薄层层析色谱)、重结晶、抽滤、烘干、熔点测定等基本实验操作,涉及到气相色谱-质谱联用、核磁共振等产物分析、表征的科研方法,渗透了单一变量法等基本科研思维,整个实验流程约需3–4 h,试剂成本~1.2元/人次,便于采用分组对照开展实际教学。总之,该新创实验既紧扣课本教材,又联系科研前沿,“顶天立地”,符合新课改“高阶性、创新性和挑战度”的要求。

Design and implementation of accelerator control monitoring system

IMPCAS has constructed and currently manages a large number of accelerator facilities. However, the current accelerator monitoring methods are unable to satisfy all of the device requirements. The accelerator control monitoring system(ACMS) was created and established to provide an efficient and accurate accelerator control monitoring system. It enables automatic alerting of problems with accelerator control systems and infrastructure. It utilizes a big data distributed stream processing engine and open-source monitoring tools. Metrics, logs, and EPICS PV values are the major three types of data that it monitors. Prometheus is primarily used to monitor metrics such as network traffic, hardware devices, and software operations. Graylog is used to monitor logs created by various applications and systems. We also created the EPICS Pulsar connector software, which allows us to transfer PV values to the Pulsar messaging cluster and use the Flink compute engine for real-time monitoring. The designed data management module allows users to define alert rules in a variety of ways. The ACMS enables the separation of the Flink business system and alarm rules. Users may use the data management module to add or alter alarm rules in real-time without having to restart the alarm software. This reduces the effect of alarm flooding when the accelerator reaches the beam shifting or shutdown condition and dramatically enhances alarm efficiency. The main components of the ACMS may be deployed in clusters, making it extremely versatile. Experimental results demonstrated that it has a higher throughput than the Phoebus Alarm system and can handle millions of monitoring indicators. The ACMS employs a modular framework that is very scalable. Long-term stability analyses were performed at the SESRI and HIRFL facilities. It achieved all of the intended goals and could greatly improve the accident handling efficiency while minimizing the failure time of the accelerator control system.

Syphilitic uveitis in HIV-positive patients: report of a case series, treatment outcomes, and comprehensive review of the literature

AIM:To report the clinical characteristics,treatment and outcomes of active syphilitic uveitis in human immunodeficiency virus(HIV)positive patients and compare them with the previously published data.METHODS:Retrospective analysis of the case series from an infectious disease center in southern China was conducted.Comprehensive review of previously published cases of HIV positive syphilitic uveitis was conducted using the PubMed and Web of Science databases and the references listed in the identified articles.RESULTS:Twelve HIV positive patients with active syphilitic uveitis were collected.All were male,with age of 36.3y(range 27 to 53y).Five(41.7%)had a history of syphilis,and three of them had received anti-syphilis treatment.Ocular manifestations included corneal epithelial defect(13%),complicated cataract(17.4%),vitreous opacity(82.6%),optic disc edema(26.1%),macular edema(30.4%),neuro-retinitis(43.5%),and retinal hemorrhage(26.1%).After standardized syphilitic treatment,intraocular inflammation was reduced and vision improved in all cases.The literature review summarizes 105 previously reported cases of HIV positive syphilitic uveitis.High serum rapid plasma regain(RPR)titers may be associated with severe uveitis and poor vision.Treatment with penicillin,ceftriaxone sodium,or penicillin plus benzylpenicillin instead of using benzylpenicillin alone can significantly improve bestcorrected visual acuity(BCVA)in HIV positive ocular syphilis patients.CONCLUSION:For HIV positive syphilitic uveitis patients,prompt diagnosis and appropriate treatment and follow-up are paramount.In our series,the clinical manifestations are diverse.Syphilis patients treated by penicillin G or long-acting penicillin before may still develop syphilitic uveitis.Patients who relapse after long-term penicillin treatment can still benefit from penicillin G.

基于灰度共生矩阵纹理特征和MLP的二极管字符识别

在二极管质量检测流水线中,因二极管字符太小难以通过肉眼准确识别,从而易造成检测效率和精度不高,甚至出现漏检等问题。设计了一种基于灰度共生矩阵纹理特征和多层感知分类器(MLP,Multi-Layer Perceptron)的二极管字符识别方法。依靠机器视觉技术,通过图像采集、图像增强、图像分割、形态学处理、灰度共生矩阵计算纹理特征参量,采用MLP等识别字符。利用纹理特征参量进行训练分类,以避免基于字符分割的MLP分类法适应性差等问题。实验结果表明,该系统能够代替人工精准识别检测二极管字符,解决了基于字符分割的MLP分类法因噪声影响而无法准确分割、适应性差等问题,从而保证了检测效率和准确度,提高了字符识别的环境适应性。

基于改进梯度加权的零件图像高精度聚焦方法

以标准量块为实验对象,针对环形光源照射下的零件图像易出现倒角特征成像存在宽边缘,手动调焦缺乏相机聚焦的客观性而导致图像聚焦不精确等问题,提出一种基于改进梯度加权的零件图像高精度聚焦方法。首先采用条形光源45°布置的照射方式,消除倒角特征在成像中的宽边缘。其次,基于改进Otsu实现自适应分割阈值获取,提取图像特征边缘点。接着,基于4方向Sobel算子获取边缘点梯度值。然后,根据像素点与其8邻域像素点灰度分布差异值大小,获取像素点梯度加权系数。最后,通过改进梯度加权的聚焦评价函数完成图像清晰度评价,获取精确聚焦图像,实现高精度尺寸测量。实验结果表明,该方法相比传统高精度测量方法精度更高,与人工测量值相对误差在0.0024%以内。改进聚焦评价函数相比传统评价函数清晰度比率平均提升75倍,灵敏度因子平均提升5倍,陡峭度平均提升1倍。

Mesozooplankton distribution and diversity from the Bering Sea shelf to the Chukchi Sea

In recent decades,environmental changes in the Arctic have aroused widespread concern around the world.To better understand ecology issues such as ecosystem dynamics,the Arctic and the subarctic regions were integrated as the“pan-Arctic”region.In this study,mesozooplankton were sampled from the Bering Sea shelf to the northern Chukchi Sea during the 10th Chinese National Arctic Research Expedition in 2019.Based on the species composition and abundance,three geographical communities were identified:the Bering Sea shelf community(BSS),the Bering Strait transitional community(BST),and the Chukchi Sea shelf community(CSS).The BSS was characterized by Bering Sea oceanic species such as Eucalanus bungii;the BST was mainly composed of the pan-Arctic distributed Calanus glacialis,meroplankton of benthos,and neritic species such as Centropages abdominalis;copepods,especially the copepodite of C.glacialis,were predominant in the CSS community.The BSS community structure was strongly affected by the inflow of Bering Shelf Water,while those of BST and CSS were determined by the recruitment of local species.The zooplankton community structure is influenced by both advection and environmental changes such as warming and a prolonged productivity period.Here,it was difficult to distinguish the changes induced by climate change from the effects of the Bering Sea Water.The key to solving this problem is the accumulation of comparable data,which requires continuous monitoring of key species such as C.glacialis and Calanus hyperboreus.

视觉检测系统的补光系统设计与优化方法

针对当前视觉检测系统光源照度优化研究未充分考虑实际检测环境存在的遮光、反光等照明干扰问题,以芯片封装质量视觉检测为例,提出一种基于图像信息的视觉检测系统补光系统设计与优化方法。该方法设计补光系统模型,并通过奇异值分解进行简化;根据图像目标区域灰度分布获取对应照度分布;以目标区域最均匀照度分布为优化目标,应用粒子群算法对补光系统各LED亮度权值进行寻优;通过Arduino控制板输出对应PWM脉冲控制LED实现补光系统对目标区域的照明优化。实验结果表明,本方法理论上可将目标区域照度均匀度提升至92%左右,且理论优化照度分布与实际优化照度分布规律基本一致。因此,提出补光光源优化方法目标合理,可用于视觉检测系统具有最优照明效果时的补光光源各LED亮度权值的获取。

生育力保存中玻璃化冷冻载杆的研究趋势及监管挑战

阐述了生育力保存过程中关键医疗器械玻璃化冷冻载杆的演化历程,分析了现有的“开放式冷冻、开放式保存”“开放式冷冻、封闭式保存”及“封闭式冷冻、封闭式保存”3种玻璃化冷冻载杆的优势与弊端,提出了玻璃化冷冻载杆的改良趋势并提供了研究思路,立足监管挑战剖析了玻璃化冷冻载杆监管关注点,为提升生育力保存的有效利用率及国产辅助生殖医疗器械的发展提供了助力。

Coordinated Rotor-Side Control Strategy for Doubly-FedWind Turbine under Symmetrical and Asymmetrical Grid Faults

In order to solve the problems of rotor overvoltage,overcurrent and DC side voltage rise caused by grid voltage drops,a coordinated control strategy based on symmetrical and asymmetrical low voltage ride through of rotor side converter of the doubly-fed generator is proposed.When the power grid voltage drops symmetrically,the generator approximate equation under steady-state conditions is no longer applicable.Considering the dynamic process of stator current excitation,according to the change of stator flux and the depth of voltage drop,the system can dynamically provide reactive power support for parallel nodes and suppress the rise of DC side voltage and rotor over-current.When the grid voltage drops asymmetrically,the positive and negative sequence components are separated in the rotating coordinate system.The doubly fed generator model is established to suppress the rotor positive sequence current and negative sequence current respectively.At the same time,the output voltage limit of the converter is discussed,and the reference value is adjusted within the allowable output voltage range.In order to adapt to the occurrence of different types of power grid faults and complex operating conditions,a fast switching module of fault type detection and rotor control mode is designed to detect the type of power grid faults and voltage drop depth in real time and switch the rotor side control mode dynamically.Finally,the simulation model of the doubly fed wind turbine is constructed in Matlab/Simulink.The simulation results verify that the proposed control strategy can improve the low-voltage ride through performance of the system when dealing with the symmetrical and asymmetric voltage drop of the power grid and identify the power grid fault type and provide the correct control strategy.

Study on the Application of Vibration Isolation by Using a Trench in Frame Structures

An isolation trench is a simple and effective method to isolate structural vibrations originating from sources of vibration other than earthquakes(machines,traffic,explosions,etc.);however,there is still not a conclusive depth of the isolation trench for frame structures.To investigate the isolation effect of a trench in the frame structure designed for ground vibration,both a field test and finite element analysis were conducted to analyze the reduced effect of the vibration.The vibration reduction analysis was based on the dynamic equation and wave theory.Considering the vibration control of an industrial plant frame,a soil-trench-building finite element model was built to analyze the vibration characteristics of the floor before and after the open isolation trench structure was used.According to the model,a dynamic test was carried out on the frame structure to assess the effect of the vibration reduction by introducing the trench.The results showed that the depth of the trench was the dominating factor in vibration isolation.When the depth of the trench reached 1~1.3 times the wavelength of the Rayleigh wave,the damping effect was the strongest.the width of the trench has little effect on the vibration isolation efficiency,and the trench must be maintained at a certain distance from the building to ensure the vibration damping efficiency.The vibration of each floor was obviously reduced after the trench was built.The vibration damping effect of the trench was significant.

基于机器视觉的齿轮自适应测量系统设计

针对采用传统方法进行齿轮测量时容易遇到测量困难与测量效率低等问题,设计了一种基于机器视觉的齿轮自适应测量系统,由机器人结合视觉定位将齿轮抓取至检测平台,利用Halcon图像处理软件提取齿轮对应参数,根据齿轮参数自动生成合适的阈值以完成多批齿轮共同测量,同时机器人利用测量信息对所测齿轮进行分组。研究结果表明,系统可以识别出不同类型的齿轮,齿轮的参数检测精度误差可以达到±0.02mm,图像系统响应时间为0.2262s,该系统大大提高了测量效率,降低了测量所需的人工成本。

基于SWOT分析的青果巷文化街区游览体验提升研究

青果巷承载着常州这座城市的经济、政治、文化、建筑艺术、城市面貌、居民生活等信息,是常州历史信息的载体和城市传统风貌的“标本”。文章研究了青果巷文化街区的设计理念、旅游价值定位和修缮过程,挖掘了青果巷街区的旅游价值;通过文献回顾和调查研究总结出青果巷文化街区的游览体验;运用SWOT法对提升青果巷文化街区游览体验进行策略分析,提出增强型、稳健性型、迎战型、预防型策略,为政府主管部门提供政策制定的参考。

醚的制备改进实验——二苯甲基乙基醚

醚的制备是有机化学实验的一个重要内容,教材中对应的实验内容是甲基叔丁基醚和正丁醚的制备。通过该部分学习对于深刻理解醇的化学性质和亲核取代反应的SN1、SN2两种机制具有重要的作用。然而,教材中基于SN1机理的甲基叔丁基醚制备实验仍存在需化学计量硫酸催化剂、反应进程不易跟踪、产物难以纯化且产率低等问题。本实验以无水三氯化铁作为催化剂,使用二苯甲醇与乙醇反应,反应混合物经洗涤除杂操作后,可以以88%–90%收率,95%–97%纯度得到二苯甲基乙基醚产物。本实验与现有教材中甲基叔丁基醚制备的反应机理和教学要点一致,但催化剂用量显著降低、产物分离纯化步骤显著减少,产物收率明显提高。本实验有助于学生深入理解碳正离子中间体的性质、有机化学中的路易斯酸碱理论及其催化反应和SN1机理等基本理论,有助于培养学生绿色化学理念。

P16蛋白在宫颈癌和宫颈上皮内瘤变中的表达及临床意义

目的分析在宫颈上皮内瘤变、宫颈癌中P16蛋白表达水平与临床意义。方法收集2019年5月-2020年12月惠州市第六人民医院上皮内瘤变、宫颈癌、宫颈炎患者共142例,根据疾病类型分组,宫颈炎组21例、宫颈癌组63例、宫颈上皮内瘤变组58例,经免疫组化染色,检测所有受试者P16水平,分析P16表达水平与宫颈病变的关系。结果本组142例受试者中,P16阳性检出97例(68.31%),阴性检出45例(31.69%);宫颈炎组患者P16阳性检出率0.00%,显著低于CIN组的70.69%、宫颈癌组的88.89%,差异有统计学意义(P<0.05)。CINⅠ级患者P16阳性检出率52.94%,显著低于CINⅡ级组(68.75%)与CINⅢ级组(84.00%),差异有统计学意义(P<0.05)。随着HR-HPV载量等级升高,P16蛋白阳性表达率越高,差异有统计学意义(P<0.05)。HR-HPV载量阳性表达在宫颈炎组中占28.57%,显著低于CINⅠ级组(70.59%)、CINⅡ级组与Ⅲ级组(80.49%)、宫颈癌组(95.24%),差异有统计学意义(P<0.05)。Spearman分析,在宫颈炎、CINⅠ级组中HR-HPV载量与P16呈正相关(P<0.01);而在宫颈癌、CINⅡ级与Ⅲ级组中,HR-HPV载量与P16表达并无明显相关性(P>0.05)。结论CIN病变程度、宫颈癌与病灶组织中P16蛋白表达存在相关性,P16可作为临床诊断重要的生物学标记。

非分散红外法应用于在用柴油车NO_x排放检测的研究

柴油车排放的NO_x量大且占比高,污染状况不容忽视。针对目前柴油车排放环保定期检验中缺少NO_x检测方法和标准的情况,采用非分散红外法对210辆柴油车NO_x排放进行实测。结果显示,加载减速检测工况中80%VelMaxHP工况点可用于柴油车NO_x排放检测,有利于识别高排放车辆。该方法的推广应用,将为今后柴油车后处理装置的效果监管和车辆NO_x实际排放的日常检测提供重要技术支撑。

基于改进凸包检测算法的多幅芯片图像校正方法

针对芯片封装缺陷视觉检测过程中存在的图像倾斜问题,以QFN(Quad Flat No-lead,方形扁平无引脚封装)芯片为实验对象,改进凸包检测算法快速获取多幅芯片图像中每个芯片的倾斜角度,解决Andrew算法构造凸包时特征点过多和计算时间较长等问题。首先,将中心焊盘的边缘点逆时针旋转45°,由下向上排序,省去获取凸包上部点集环节,减少构造凸包计算量;接着,通过滤除凸度小于20的凸包点以减少凸包点集数量,再将凸包点集顺时针旋转45°,由下向上排序,从而在精准获取凸包点集的同时解决簇拥问题;最后,应用凸包点集获取多幅芯片图像中每个芯片的倾斜角度和旋转中心,并应用仿射变换实现芯片图像校正。实验结果表明,与传统Hough变换校正方法、最小外接矩形校正方法、傅里叶变换校正方法相比,采用最小外接正矩形标记芯片位置信息,应用ROI(Regions of Interest)完成校正后的芯片图像提取,省去了单幅芯片图像的切分环节,且通过改进Andrew算法获取的芯片倾斜角度更加精准。此方法同样适用于可通过水平或垂直轮廓线来表示倾斜角度,且存在L型轮廓边缘点的图像。

2013年夏季宁夏一次强降水过程风廓线雷达回波特征分析

2013年7月9日宁夏出现了一次强降水天气过程,利用边界层风廓线雷达探测资料、多普勒天气雷达风廓线产品及常规观测资料,对本次过程最强降水时段雷达产品特征进行分析。结果表明:灵武站700 hPa附近存在12 m/s以上的偏东风急流和大小为0.033 s-1的风切变,是灵武站最大小时雨强大于银川站的主要原因;银川站从地面到900 m高度以下大气水汽含量较少,导致银川站累积降水量小于灵武站;在最强降水时段,灵武站风廓线雷达产品的中低层速度谱宽维持在1.2 m/s并接地,最大速度谱宽出现在700 hPa,达2.0 m/s;信噪比达到35 dB的高度层超过10个;700 hPa以上大气折射率结构常数达1.0×10-10及中低层向下垂直速度达10 m/s。研究结果揭示了风廓线雷达产品与强降水过程之间的联系,可作为灵武站是否出现强降水的判别指标。

四旋翼飞行器双环条件积分滑模控制

针对存在阵风干扰及未建模特性下的四旋翼飞行器轨迹跟踪控制,基于非线性滑模控制技术,结合条件积分思想及Lyapunov稳定性理论设计了一种位姿双环条件积分滑模控制器。在获得四旋翼非线性动力学模型后对其进行线性化,简化被控对象数学模型,提高控制器设计效率。利用条件积分滑模控制律设计了位置环和姿态环的轨迹跟踪控制器,实现了控制系统的全局渐近稳定。通过仿真算例验证了所设计控制器的有效性,结果表明:与其他控制器相比,所设计的控制器具有较高的控制精度、较强的抗干扰性及鲁棒性,可有效抑制系统振动、消除静态误差,并实现四旋翼飞行器的高性能轨迹跟踪。

视觉检测系统LED光源照度优化方法

针对当前视觉检测系统LED光源照度优化研究中存在的照度效果评价因素单一、照度优化方法通用性不足等问题,以芯片封装质量视觉检测为例,提出一种基于改进樽海鞘算法的LED光源照度优化方法。该方法在单个LED光源照度数学模型基础上,建立标准条形LED阵列光源照度数学模型,获取条形LED阵列在任意空间位姿与被测面的照度值;基于照度均匀度、照度梯度变化与对中度、平均照度、目标与背景区分度等因素建立平面照度效果评价函数;提出改进樽海鞘算法,通过改进算法收敛系数、速度、领导者与追随者位置等更新策略,增强区域搜索的多样性;应用改进樽海鞘算法对平面照度效果评价函数进行优化求解,获取具有最优照度效果的空间位姿参数。实验结果表明:考察优化区域的相对照度分布,文中提出的LED光源照度优化方法所得照度分布与实际测量所得照度分布结果基本一致,目标区域理论照度均匀度在98.78%以上,误差在5.57%以内。因此文中提出方法优化目标合理,可用于视觉检测系统具有最优照度效果时光源位姿信息参数的获取。