Retinal nerve fiber layer defects and chronic kidney disease:the Kailuan Eye Study

AIM:To investigate whether retinal nerve fiber layer defects(RNFLDs)is a potential risk factor for chronic kidney disease(CKD)in Chinese adults.METHODS:The Kailuan Eye Study was a populationbased study that included 14440 participants.All participants underwent detailed assessments,RNFLDs were diagnosed using color fundus photographs.RESULTS:Overall,12507 participants[8533 males(68.23%)]had complete systemic examination data and at least one evaluable fundus photograph.RNFLDs were found in 621 participants[5.0%;95%confidence interval(CI):4.6%-5.34%],and 70 cases of multiple RNFLDs were found(11.27%).After adjusting multiple factors,RNFLDs was significantly associated with CKD severity,the ORs of CKD stage 3,stage 4 and stage 5 were 1.698,4.167,and 9.512,respectively.Multiple RNFLDs were also associated with CKD severity after adjusting multiple factors,the ORs of CKD stage 3 and stage 5 were 4.465 and 11.833 respectively.Furthermore,2294 participants had CKD(18.34%,95%CI:17.68%-18.99%).After adjusting for other factors,CKD presence was significantly correlated with the presence of RNFLDs.CONCLUSION:The strongest risk factors for RNFLDs are CKD and hypertension.Conversely,RNFLDs can be an ocular feature in patients with CKD.Fundoscopy can help detect systemic diseases,and assessment for RNFLDs should be considered in CKD patients.

Analysis of risk and protective factors associated with retinal nerve fiber layer defect in a Chinese adult population

AIM:To investigate the risk and protective factors associated with the retinal nerve fiber layer defect(RNFLD)in a Chinese adult population.METHODS:This study was a cross-sectional populationbased investigation including employees and retirees of a coal mining company in Kailuan City,Hebei Province.All the study participants underwent a comprehensive systemic and ophthalmic examination.RNFLD was diagnosed on fundus photographs.Binary logistic regression was used to investigate the risk and protective factors associated with the RNFLD.RESULTS:The community-based study included 14440 participants.There were 10473 participants in our study,including 7120 males(68.0%)and 3353 females(32.0%).The age range was 45-108y,averaging 59.56±8.66y.Totally 568 participants had RNFLD and the prevalence rate was 5.42%.A higher prevalence of RNFLD was associated with older age[P<0.001,odds ratio(OR):1.032;95%confidence interval(CI):1.018-1.046],longer axial length(P=0.010,OR:1.190;95%CI:1.042-1.359),hypertension(P=0.007,OR:0.639;95%CI:0.460-0.887),and diabetes mellitus(P=0.019,OR:0.684;95%CI:0.499-0.939).The protective factors of RNFLD were visual acuity(P=0.038,OR:0.617;95%CI:0.391-0.975),and central anterior chamber depth(P=0.046,OR:0.595;95%CI:0.358-0.990).CONCLUSION:In our cross-sectional community-based study,with an age range of 45-108y,RNFLD is associated with older age,longer axial length,hypertension,and diabetes mellitus.The protective factors of RNFLD are visual acuity and central anterior chamber depth.These can help to predict and evaluate RNFLD related diseases and identify high-risk populations early.

Study on electrical defects level in single layer two-dimensional Ta2O5

Two-dimensional atomic-layered material is a recent research focus, and single layer Ta205 used as gate dielectric in field-effect transistors is obtained via assemblies of Ta205 nanosheets. However, the electrical performance is seriously affected by electronic defects existing in Ta2Os. Therefore, spectroscopic ellipsometry is used to calculate the transition energies and corresponding probabilities for two different charged oxygen vacancies, whose existence is revealed by x-ray photoelectron spectroscopy analysis. Spectroscopic ellipsometry fitting also calculates the thickness of single layer Ta2Os, exhibiting good agreement with atomic force microscopy measurement. Nondestructive and noncontact spectroscopic ellipsometry is appropriate for detecting the electrical defects level of single layer Ta2O5.

Effect of Defects at the Buffer Layer CdS/Absorber CIGS Interface on CIGS Solar Cell Performance

This scientific paper presents a study investigating the effects of defects at the CdS/CIGS and CdS/SDL interfaces on the performance of CIGS solar cells. The objective of this study is to analyze the influence of defects at the interface between the CdS buffer layer and the CIGS absorber, as well as the surface defect layer (SDL), on CIGS solar cell performance. The study explores three key aspects: the impact of the conduction band offset (CBO) at the CdS/CIGS interface, the effects of interface defects and defect density on performance, and the combined influence of CBO and defect density at the CdS/ SDL and SDL/CIGS interfaces. For interface defects not exceeding 1013 cm-2, we obtained a good efficiency of 22.9% when -0.1 eV analyzing the quality of CdS/SDL and SDL/CIGS junctions, it appears that defects at the SDL/CIGS interface have very little impact on the performances of the CIGS solar cell. By optimizing the electrical parameters of the CdS/SDL interface defects, we achieved a conversion efficiency of 23.1% when -0.05 eV < CBO < 0.05 eV.

Improvement in IBC-silicon solar cell performance by insertion of highly doped crystalline layer at heterojunction interfaces

By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact （IBC） silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters （doping concentration and thickness） is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of 2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si：H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density.

电容屏破损缺陷局部放电过程规律特征及仿真分析

油纸电容式变压器套管因性能好、成本低而被广泛采用。当电容屏存在边缘破损工艺缺陷时易发生局部放电,进而会改变油纸绝缘性能,缩短套管使用寿命,严重时危及电网设备安全运行。为研究电容屏破损局部放电过程变化规律,明确放电发展阶段,该文搭建了缺陷套管放电实验模型分析局放过程中相位谱图、放电量等参数发展规律,并基于实验规律及流体漂移扩散理论、固体双极电荷传输理论,建立了末屏缺陷针板沿面放电过程仿真模型,结合仿真中电荷形态变化、放电时间及油纸界面电荷密度分布对电容屏破损放电过程进行阶段划分:放电初始阶段,铝箔尖端电荷聚集发生电晕放电;放电发展阶段,尖端处带电粒子在电场作用下向油纸发展,小部分达到油纸界面产生沿面放电;放电破坏阶段,经过长时间沿面放电进入油纸发生预击穿,电场强度更大使带电粒子能量更高,冲击油纸表面造成油纸表面纤维素断裂炭化形成通道。仿真结果与实验结论相对应,证明了仿真的有效性。该文的研究成果进一步阐明了油纸套管电容屏工艺缺陷局部放电的过程及机理。

高压XLPE电缆缓冲层缺陷研究现状综述

高压交联聚乙烯电缆因缓冲层缺陷引发的故障频发,已严重威胁到电力系统的安全运行。本文首先介绍了缓冲层的基本结构和作用,并在此基础上梳理了目前国内外对于缓冲层失效的相关研究;其次从缓冲层的材料特征和内部结构等角度结合电场仿真来分析缺陷发生的主要原因;之后对缓冲层缺陷中出现的白色粉末绝缘性能和理化特征进行总结,并提出其形成机理;最后对缓冲层缺陷的检测手段进行汇总,提出使用计算机断层成像技术对电缆缓冲层缺陷进行检测以弥补现有检测手段的不足,并建议对铝护套及缓冲层的材料或结构进行优化,以预防缓冲层缺陷的生成。

Characterization of Cd1-xZnxTe（0≤x≤1） Nanolayers Grown by Atomic Layer Deposition on GaSb and GaAs（001） Oriented Substrates

ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (ALD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (LO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the LO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.

Impacts of Temperature and Frequency on the Dielectric Properties for Insight into the Nature of the Charge Transports in the Tl2S Layered Single Crystals

Investigation of the electric properties of semi-conducting materials in an applied ac electric fields gives information about the nature of charge transport and localized states in the forbidden gap. Layered crystals usually contain structural defects, such as dislocations and vacancies that may form a high density of localized states near the Fermi level. So, the current study was carried out for insight into the dielectric Properties of Tl2S layered single crystals. These properties were studied using the ac measurements in the low temperatures ranging from 77 to 300 K. The real part of dielectric constant ε?, imaginary part of dielectric constant ε?, the dissipation factor tan δ and the alternating current conductivity σac were measured in an applied ac electric field of frequencies extending from 2.5 to 50 kHz. Based on the dependencies of these dielectric parameters on both the frequency and temperature, the dielectric properties of the crystals under investigation were elucidated and analyzed. The ac conductivity was found to obey the power law σac(ω) = Aωs with which the values of the exponent s were evaluated to be less than unity in the range 0.21 ≥ s ≥ 0.19. Furthermore, it was found that the temperature dependence of ac conductivity follows the Arrhenius relation via which the impact of temperature on the electrical processes in an applied ac electric field was illustrated and analyzed. The influences of temperature and frequency on both the exponent s and band gap were also discussed in this investigation.

Analysis for the Defect of Chromatogram in 35kv Oil-immersed Electric Reactor

A defect of chromatogram in a 35kV oil-immersed three-phase one-piece electric reactor in a 500kV substation。The initial analysis suggests that the defect is caused by the loose connection of the iron core magnet shield (magnet shield layer of iron core or earthling top). Examination of winding DC resistance, DGA and other relevant examinations were carried out to investigate the defect reasons., which is demonstrated by the dismantlement. In-depth study is taken and corresponding prevention measures are put forward in the paper.

金属铀氢化腐蚀研究进展

金属铀在核能工业领域具有重要应用。铀元素具有活泼的化学性质,极易与环境中的气体、液体甚至固体介质发生反应引起表面腐蚀。金属铀的氢化腐蚀既是关系铀材料长期贮存安全性的实际工程问题,同时也是核材料腐蚀科学研究领域当前最活跃的基础科学问题之一。本文基于铀-氢反应基础及氢化腐蚀的危害,围绕金属铀氢化腐蚀动力学及氢化物形核长大的最新研究进展进行阐述,重点讨论环境因素、材料学因素对铀氢化腐蚀行为的影响。

Study of point defect detectors in Si

The importance of point defects in semiconductor and function materials has been studied in detail, but effective means for detecting point defects has notbeen available for a long time. The end of range defects in St, produced by 140keVGe+ implantation, were investigated as detectors for measuring the interstitial concentration created by 42 keV B+ implantation. The concentration of interstitial resultingfrom the B+ implantation and the behavior of the interstitial flux under different annealing condition were given. The enhanced diffusion in the boron doped EPI marker,resulting from mobile non-equilibrium interstitials was demonstrated to be transient.Interstitial fluxes arising from processing can be detected by transient enhanced diffusion (TED) of doped marker layers as well.

Structure-function relationship comparison between retinal nerve fibre layer and Bruch's membrane opening-minimum rim width in glaucoma

AIM：To evaluate and compare structural optical coherence tomography（OCT）-based parameters,such as Bruch’s membrane opening-minimum rim width（BMO-MRW）,and retinal nerve fiber layer（RNFL）thickness in glaucoma patients with visual field（VF）defects,and to correlate both to mean deviation（MD）values of obtained standard achromatic perimetry（SAP）examinations.METHODS：Patients with glaucoma and glaucomatous VF defects were enrolled in this prospective study and compared to age-matched healthy individuals.All study participants underwent a full ophthalmic examination and VF testing with SAP.Peripapillary RNFL thickness and BMO-MRW were acquired with SD-OCT.Correlation analyses between obtained global functional and global as well as sectorial structural parameters were calculated.RESULTS：A consecutive series of 30 glaucomatous right eyes of 30 patients were included and compared to 36healthy right eyes of 36 individuals in the control group.Global MD of values correlated significantly with global RNFL（Pearson corr.coeff：0.632,P=0.001）and global BMO-MRW（Pearson corr.coeff：0.746,P〈0.001）values in the glaucoma group.Global MD and sectorial RNFL or BMO-MRW values correlated less significantly.In the control group,MD values did not correlate with RNFL or BMO-MRW measurements.A subgroup analysis of myopic patients（〉4 diopters）within the glaucoma group（n=6）revealed a tendency for higher correlations between MD and BMO-MRW than MD and RNFL measurements.CONCLUSION：In a clinical setting,RNFL thickness and BMO-MRW correlate similarly with global VF sensitivity in glaucoma patients with BMO-MRW showing higher correlations in myopic glaucoma patients.

基于机器学习的黏钢构件黏接层缺陷识别方法研究

对黏钢加固结构黏接层缺陷对超声检测信号的影响进行了深入研究,并提出了一种基于机器学习的黏接层缺陷识别的新型方法.首先,该文基于直接接触式的脉冲回波反射法对黏钢构件进行有限元模拟,并阐述了超声波在黏钢构件中的传播规律;其次,通过分析局部段超声回波信号及相关信号特征,讨论了不同缺陷变量对超声回波信号的影响规律;最后,建立了黏钢构件超声时程响应数据集,并对比了不同机器学习模型对缺陷大小、位置的分类识别性能,形成了黏钢构件黏接层缺陷识别方法.结果表明,局部段超声回波信号及其特征随着缺陷大小、位置的改变呈规律性变化,能够对缺陷信息进行初步区分.同时,该文提出的基于RF模型的黏钢构件黏接层缺陷识别方法能够有效识别黏钢构件黏接层缺陷,具有较广阔的工程应用前景.

基于X射线成像原理的电缆缓冲层缺陷的可视化检测技术对比研究

近年来,高压电缆缓冲层烧蚀缺陷导致电缆故障问题频发,如何有效地对缓冲层缺陷进行检测引起了行业内的广泛关注。基于缓冲层缺陷与其相邻层间的密度差异,分别对X射线数字成像技术和计算机断层成像技术开展了检测参数研究,对比分析了两种方法对不同类型缺陷的检出有效性及在不同干扰下的检测效果。结果表明,计算机断层成像技术在检测准确度和抗干扰性优于X射线数字成像技术,但在检测的现场适用性方面有局限。研究给出两种检测技术的最佳检测参数及各自的优缺点,为后续高压电缆的缓冲层缺陷可视化检测提供了有益的参考。

滤波电缆原理与应用展望

电缆被称为工业的“血管”和“神经”,广泛应用于设备互联。然而,传统电缆不具备分布式滤波功能,通常成为电磁兼容(EMC)性问题的主要耦合路径。滤波电缆,可以通过在绝缘电线上包裹采用柔性印刷电路板(FPCB)制造的特定缺陷导体层(DCL)、在绝缘圆柱体上包裹缺陷导体传输结构(DCTS),使其能够在轴向上实现分布式滤波功能。DCL或DCTS上具有特定蚀刻图案的导体起到等效的集总电路作用,被加到电缆电路中实现滤波功能,从而抑制干扰信号。采用微波网络分析技术可以高效地分析级联特性。国内外的研究现状和本团队的主要研究成果表明,滤波电缆能够有效实现分布式滤波功能,有望为复杂电磁环境防护提供一种新的解决方案。

基于多层融合振动数据分析的GIS设备机械缺陷诊断方法研究

气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear,GIS)机械缺陷是导致设备故障的重要因素,针对单测点、单证据机械缺陷诊断模型信息缺失和精度不足问题,该文提出一种多层融合振动数据分析的GIS设备机械缺陷诊断方法。首先,基于真型GIS设备振动模拟平台试验研究测点位置与缺陷类型对振动行为的影响特性;然后,联合统计分析、模态分解、尺度变换方法提出机械振动信号整体与局部信息关注的复合参数分析方法,引入主成分分析开展多测点振动信息的特征层融合降维;最后,提出改进放缩权重的Dempster-Shafer(DS)证据理论和Bagging投票机制的强/弱基学习器决策层融合机制,联合构建多层融合振动数据分析的GIS设备机械缺陷诊断模型。结果表明:不同类型机械缺陷信号的响应幅值、特征频点和畸变程度存在显著差异,复合特征参量大小及分散程度各不相同;同时,测点位置对缺陷信号的复合振动特征参量的表现形式及分布区间也具有一定影响;基于多层融合数据分析的诊断模型实现缺陷有效识别,辨识准确率为98.66%,相比单一分类器诊断效果提升5.83%。该文可为GIS设备机械缺陷诊断方法提供有价值的参考。

内衬GFRP防护复合管壁原缺陷坑处应力重分布规律分析

为了深入研究内衬GFRP防护复合管壁在其原管道内腐蚀缺陷坑处的应力重分布状态以及其修复的效果,利用弹塑性力学中的平衡微分方程,建立了管道内腐蚀缺陷处的数学模型,采用有限单元法建立了含单个腐蚀缺陷的管道模型,并通过改变腐蚀缺陷坑的深厚比,将修复前后腐蚀缺陷坑处的应力状态进行对比分析。分析结果表明,腐蚀缺陷坑的深厚比对管道的应力分布有着显著的影响,所以在进行管道安全评估时应注意腐蚀坑深度的影响;在腐蚀缺陷坑深厚比0.1到0.8的分次增加的过程中,管壁腐蚀缺陷处的周向应力,径向应力,Mises应力都有增大的趋势;修复前腐蚀缺陷坑处的周向应力和Mises应力相近,径向应力较前两者小,三者中周向应力最大;在修复前后,管道腐蚀缺陷处的控制应力一般是周向应力,管道的失效可依据周向应力进行判断;修复后的内衬GFRP防护复合管壁,原始腐蚀缺陷坑处发生了应力重分布,其周向应力与Mises应力均有减小,修复效果明显。