Ⅰ型倍增层对异质SAM结构InSb-APD红外探测器性能的影响

红外探测器的光电特性会受到内部结构倍增层参数的影响,为了能够改善器件的雪崩效应,借助仿真软件Silvaco-TCAD,详细探讨了Ⅰ型倍增层的残余掺杂浓度和厚度对异质SAM结构InSb-APD红外探测器性能的影响。研究结果表明,随着Ⅰ型倍增层掺杂浓度的增加,其倍增层内的电场强度峰值增加,同时光响应度略微增加;随着Ⅰ型倍增层厚度的增加,其倍增层的光响应度与暗电流密度升高,同时电场强度峰值减少。进一步研究表明,当Ⅰ型倍增层残余掺杂浓度和厚度分别为1×10^(15)cm^(−3)和3μm时,有利于雪崩过程。

结合SAM大模型和数学形态学的历史地图水系信息提取方法

历史地图记载着丰富的历史地理信息,能够帮助了解历史规律,为当代发展提供借鉴。不同于现代地图、遥感影像等数据,历史地图保存时间久,存在留存数量少、图像精度低等问题,地图符号也与现代有所差异,因此信息难以被高效提取。针对该问题,本文以历史地图《宁夏省境黄河沿岸沟渠水道地形图》为试验数据,提出一种智能化历史地图水系信息提取方法。首先,结合符号句法,运用聚类与数学形态学方法构建数据集;然后,改进通用大模型(SAM)结构并进行迁移学习优化权重;最后,借助改进SAM自动提取历史地图水系信息。将试验结果与其他模型作对比,显示本文方法提取结果边界清晰,轮廓完整,准确率、精度等指标均为最高。同时,将提取结果与该区域水系现状作对比,发现历史上的河流沟渠如今大多改道、偏移或消失,湖泊面积大大减小。本文方法基于SAM通用大模型进行改进,验证了大模型在地图领域的可用性,为地图信息提取提供了思路。

新几内亚凤仙CCoAOMT和SAMS基因的克隆及表达分析

通过对新几内亚凤仙(Impatiens hawkeri)指甲花醚合成相关基因CCoAOMT和SAMS的克隆及表达分析,以期为解析其合成途径提供一定的理论依据。基于新几内亚凤仙指甲花醚含量测定和转录组测序数据分析,克隆到1个CCoAOMT和2个SAMS基因,将其命名为IhCCoAOMT、IhSAMS1和IhSAMS2。3种处理(光培养、暗培养和前体物DHNA (1,4-dihydroxy-2-naphthoate)诱导)均能促进指甲花醚积累,且暗培养处理最佳。IhCCoAOMT的cDNA全长为729 bp,编码242 aa,其蛋白具有AdoMet_MTases超家族结构域;IhSAMS1和IhSAMS2的cDNA全长分别为1179 bp和1173 bp,分别编码393 aa和391 aa,其蛋白均具有S-AdoMet_synt超家族结构域。系统进化分析表明,IhCCoAOMT与喜马拉雅凤仙亲缘关系最近;IhSAMS1与IhSAMS2可能为旁系同源。qRT-PCR分析表明,3个基因在新几内亚凤仙的3个处理及4个时期中均有表达,其中IhCCoAOMT在暗培养及前体物DHNA诱导中表达量整体上调,且暗培养第60天时表达量最高;IhSAMS1和IhSAMS2在暗培养及DHNA诱导中表达量整体下调,但IhSAMS1在DHNA诱导中表达量较高,IhSAMS2在暗培养中表达量较高。综上所述,推测IhCCoAOMT在指甲花醚处理后期起主要作用,IhSAMS1和IhSAMS2在其早期起主要作用,且IhSAMS2作用更为显著。

基于SAM&ImageJ图像处理的堆石混凝土坝层面露石率研究

堆石混凝土坝层面的外露块石为上下层提供了重要的啮合作用,其投影面积比例是科学评价层间抗剪性能的重要指标。采用国际最新Meta AI模型segment anything model(SAM)对层面外露堆石进行自动图像分割,并基于ImageJ软件对SAM识别后的图片进行再加工与图像计算,利用平滑、差分算法、中值滤波等方法精准标定外露堆石,二值化后计算得到层面露石率。结果表明:SAM图像预分割可识别约90%的外露堆石,经过ImageJ二次图像处理后可有效提高小粒径堆石的识别精度,对比手动标注结果误差在±3%以内。以贵州省两座水库的工程应用为例,对浇筑仓面进行分区预处理,结果发现靠近上游、中部、下游不同区域的露石率差别较大,计算得到的层面露石率以10%~30%居多,其中堆石入仓运输通道区域的露石率较低。研究内容与结论可为堆石混凝土结构层间界面抗剪力学性能和大坝蓄水安全稳定的研究提供参考与借鉴。

基于时差提示SAM的遥感变化检测

遥感变化检测作为观测和分析地表变化的重要手段,以双时相图像为输入,旨在预测变化发生的“位置”。近期出现的基础模型,例如SAM模型(Segment Anything Model),展现出强大的通用性和泛化能力,有望为变化检测任务提供更为有效的解决方案。然而,由于遥感图像的特殊成像特性,它们在许多遥感应用中的直接使用往往效果不佳。此外,SAM模型最初被设计用于分割单时相图像,其通过人工添加点或框的提示来实现,但这种过于直观的方法在处理双时相图像输入时并不适用。为了应对上述挑战,本文提出了一种基于时差提示SAM的遥感变化检测方法(TDPS),充分发挥SAM模型强大的视觉识别能力,以改进对遥感图像的变化检测。具体而言,本文首先在SAM骨干网络中引入了低阶可微调参数,以减轻自然图像到遥感图像上的域偏移。其次,本文设计了时相差异提示生成器,通过将双时相图像的特征与查询嵌入一起优化,得到适用于变化检测任务的提示向量。最后,大量实验证明了本文方法的有效性,在两个常用的变化检测数据集LEVIR-CD和WHU-CD上取得了最先进的性能,F1指标相比于最先进方法分别提升了1.4%和2.5%。

Acousto-optic scanning multi-photon lithography with high printing rate

As a manufacturing method that is focused on end-users,3D printing has gained a lot of attention in recent years due to its unique advantages in fabricating complex three-dimensional structures.Various new micro-nano 3D printing methods have been developed to meet the demand for high-precision and high-yield manufacturing1-9.Among them,multi-photon-photon lithography(MPL) is a promising 3D nanofabrication technology due to its capability of true 3D digital processing and nanoscale processing resolution beyond the diffraction limit.It has been widely used to fabricate microoptics10,11,photonic crystals12,microfluidics13,meta-surfaces14,and mechanical metamaterials15.

Investigation of reflection anisotropy induced by micropipe defects on the surface of a 4H-SiC single crystal using scanning anisotropy microscopy

Optical reflection anisotropy microscopy mappings of micropipe defects on the surface of a 4H-SiC single crystal are studied by the scanning anisotropy microscopy(SAM)system.The reflection anisotropy(RA)image with a'butterfly pattern'is obtained around the micropipes by SAM.The RA image of the edge dislocations is theoretically simulated based on dislocation theory and the photoelastic principle.By comparing with the Raman spectrum,it is verified that the micropipes consist of edge dislocations.The different patterns of the RA images are due to the different orientations of the Burgers vectors.Besides,the strain distribution of the micropipes is also deduced.One can identify the dislocation type,the direction of the Burgers vector and the optical anisotropy from the RA image by using SAM.Therefore,SAM is an ideal tool to measure the optical anisotropy induced by the strain field around a defect.

SAM Era:Can It Segment Any Industrial Surface Defects?

Segment Anything Model(SAM)is a cutting-edge model that has shown impressive performance in general object segmentation.The birth of the segment anything is a groundbreaking step towards creating a universal intelligent model.Due to its superior performance in general object segmentation,it quickly gained attention and interest.This makes SAM particularly attractive in industrial surface defect segmentation,especially for complex industrial scenes with limited training data.However,its segmentation ability for specific industrial scenes remains unknown.Therefore,in this work,we select three representative and complex industrial surface defect detection scenarios,namely strip steel surface defects,tile surface defects,and rail surface defects,to evaluate the segmentation performance of SAM.Our results show that although SAM has great potential in general object segmentation,it cannot achieve satisfactory performance in complex industrial scenes.Our test results are available at:https://github.com/VDT-2048/SAM-IS.

A review of understanding electrocatalytic reactions in energy conversion and energy storage systems via scanning electrochemical microscopy

To address climate change and promote environmental sustainability,electrochemical energy conversion and storage systems emerge as promising alternative to fossil fuels,catering to the escalating demand for energy.Achieving optimal energy efficiency and cost competitiveness in these systems requires the strategic design of electrocatalysts,coupled with a thorough comprehension of the underlying mechanisms and degradation behavior occurring during the electrocatalysis processes.Scanning electrochemical microscopy(SECM),an analytical technique for studying surface electrochemically,stands out as a powerful tool offering electrochemical insights.It possesses remarkable spatiotemporal resolution,enabling the visualization of the localized electrochemical activity and surface topography.This review compiles crucial research findings and recent breakthroughs in electrocatalytic processes utilizing the SECM methodology,specifically focusing on applications in electrolysis,fuel cells,and metal–oxygen batteries within the realm of energy conversion and storage systems.Commencing with an overview of each energy system,the review introduces the fundamental principles of SECM,and aiming to provide new perspectives and broadening the scope of applied research by describing the major research categories within SECM.

Fatigue properties and damage constitutive model of salt rock based on CT scanning

To investigate the macroscopic fatigue properties and the mesoscopic pore evolution characteristics of salt rock under cyclic loading,fatigue tests under different upper-limit stresses were carried out on salt rock,and the mesoscopic pore structures of salt rock before and after fatigue tests and under different cycle numbers were measured using CT scanning instrument.Based on the test results,the effects of the cycle number and the upper-limit stress on the evolution of cracks,pore morphology,pore number,pore volume,pore size,plane porosity,and volume porosity of salt rock were analyzed.The failure path of salt rock specimens under cyclic loading was analyzed using the distribution law of plane porosity.The damage variable of salt rock under cyclic loading was defined on basis of the variation of volume porosity with cycle number.In order to describe the fatigue deformation behavior of salt rock under cyclic loading,the nonlinear Burgers damage constitutive model was further established.The results show that the model established can better reflect the whole development process of fatigue deformation of salt rock under cyclic loading.

Algorithm of automatic identification of diabetic retinopathy foci based on ultra-widefield scanning laser ophthalmoscopy

AIM:To propose an algorithm for automatic detection of diabetic retinopathy(DR)lesions based on ultra-widefield scanning laser ophthalmoscopy(SLO).METHODS:The algorithm utilized the FasterRCNN(Faster Regions with CNN features)+ResNet50(Residua Network 50)+FPN(Feature Pyramid Networks)method for detecting hemorrhagic spots,cotton wool spots,exudates,and microaneurysms in DR ultra-widefield SLO.Subimage segmentation combined with a deeper residual network FasterRCNN+ResNet50 was employed for feature extraction to enhance intelligent learning rate.Feature fusion was carried out by the feature pyramid network FPN,which significantly improved lesion detection rates in SLO fundus images.RESULTS:By analyzing 1076 ultra-widefield SLO images provided by our hospital,with a resolution of 2600×2048 dpi,the accuracy rates for hemorrhagic spots,cotton wool spots,exudates,and microaneurysms were found to be 87.23%,83.57%,86.75%,and 54.94%,respectively.CONCLUSION:The proposed algorithm demonstrates intelligent detection of DR lesions in ultra-widefield SLO,providing significant advantages over traditional fundus color imaging intelligent diagnosis algorithms.

Optical scanning endoscope via a single multimode optical fiber

Optical endoscopy has become an essential diagnostic and therapeutic approach in modern biomedicine for directly observing organs and tissues deep inside the human body,enabling non-invasive,rapid diagnosis and treatment.Optical fiber endoscopy is highly competitive among various endoscopic imaging techniques due to its high flexibility,compact structure,excellent resolution,and resistance to electromagnetic interference.Over the past decade,endoscopes based on a single multimode optical fiber(MMF)have attracted widespread research interest due to their potential to significantly reduce the footprint of optical fiber endoscopes and enhance imaging capabilities.In comparison with other imaging principles of MMF endoscopes,the scanning imaging method based on the wavefront shaping technique is highly developed and provides benefits including excellent imaging contrast,broad applicability to complex imaging scenarios,and good compatibility with various well-established scanning imaging modalities.In this review,various technical routes to achieve light focusing through MMF and procedures to conduct the scanning imaging of MMF endoscopes are introduced.The advancements in imaging performance enhancements,integrations of various imaging modalities with MMF scanning endoscopes,and applications are summarized.Challenges specific to this endoscopic imaging technology are analyzed,and potential remedies and avenues for future developments are discussed.

Three-dimensional finite element simulation and reconstruction of jointed rock models using CT scanning and photogrammetry

The geometry of joints has a significant influence on the mechanical properties of rocks.To simplify the curved joint shapes in rocks,the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations.In this study,the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample,respectively.To describe the joint geometry,the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models.For comparison tests,the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method.The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints.The presence of joints reduces the uniaxial compressive strength (UCS),elastic modulus,and released acoustic emission (AE) energy of rocks by 37%–67%,21%–24%,and 52%–90%,respectively.Compared to the simplified joint sample,the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints.The UCS,accumulative released AE energy,and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample.The UCS value of the simplified joint sample (i.e.38.5 MPa) is much lower than that of the CT-based sample (i.e.72.3 MPa).Additionally,the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample.CT scanning provides a reliable means to visualize the joints in rocks,which can be used to verify the reliability of photogrammetry techniques.The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.

基于SAM的无人艇多源图像分割研究

针对无人艇多源传感器的图像分割问题,开展了结合图像分割大模型与大模型低成本微调技术的研究,以增强感知大模型在无人系统上的实用性。首先将分割大模型应用于无人艇可见光、红外和声学图像分割,并对其性能进行了比较。经对比发现,分割大模型对可见光和红外图像分割效果好,但对声学图像的分割性能存在严重下降。随后利用低秩自适应算法对分割大模型编码器部分进行了微调训练,以适应声学图像分割任务。微调后的分割大模型对声学图像的分割性能得到显著提升,Dice相似系数平均值相比初始分割大模型提高了52.88%,证明了方法的有效性。作为一种大模型的微调技术,低秩自适应算法使用低秩近似来降低权重矩阵维度,大幅减少模型中可训练的参数量,在提升训练效率的同时降低了训练成本。

基于SAM教学系统设计模型的钉钉医学检验实践教学分层培训系统构建

目的基于钉钉构建医学检验实践教学分层培训系统。方法2019年3月—2021年12月,课题组以SAM教学系统设计模型为理论框架,分析检验学员实践教学分层培训需求,基于钉钉系统对宜宾市第二人民医院检验科检验实践教学分层培训系统功能进行设计、开发。结果2019年完成钉钉医学检验实践教学分层培训系统的构建,对培训系统进行试运行,通过评价反馈进一步改进。至2021年12月该系统开设了104个规培、进修、实习学员分层课程,共162人参与网上学习,3216人次自主完成课程学习并通过在线考核,培训人员满意度达98.15%。结论基于SAM教学系统设计模型的钉钉医学检验实践教学分层培训软件可以用于医学检验实践教学,值得进一步推广应用。

基于SAM敏捷迭代技术高职网络营销课程开发研究

SAM敏捷迭代技术非常符合数字化、信息化教学趋势下的3个特征:敏捷、体验、迭代。文章通过对国内外相关文献进行综述和分析,尝试探究SAM敏捷迭代技术在高职网络营销课程开发应用的可能性,阐述了SAM敏捷迭代模型——准备阶段、迭代设计阶段和迭代开发阶段的开发步骤。

The Study on the Self-assembled Monolayer(SAMs)of Porphyrin with Different Chain Length by Scanning Electrochemical Microscopy(SECM)

The thiol-porphyrins were prepared to investigate the effect of spacer length on the gold electrode. These measurements showed that as the length of the spacers increases, the SAMs tend to form highly ordered structures on the gold electrodes. In addition, the structures of the monoalyers vary depending on the even and odd number of the methylene spacers （n）.

SAM和ENSO对罗斯海和阿蒙森海区域冬季气候的影响

本研究利用ERA5数据对南半球环状模(SouthernAnnularMode,SAM)正、负位相和ENSO(El Ni?o-SouthernOscillation)事件发生时罗斯海和阿蒙森海冬季风场、气温和海平面气压进行合成分析,并深入分析了SAM和ENSO对冬季阿蒙森低压(Amundsen Sea Low,ASL)的影响,通过对典型区域进行经验正交分解(Empirical Orthogonal Function,EOF),结合ASL中心的位置变化,解释了SAM和ENSO事件同时发生时该区域风场的变化特征。结果表明,在罗斯海和西阿蒙森海,主要由SAM和ENSO通过影响ASL的纬向位置来影响该区域的风场,当SAM正位相和拉尼娜事件同时发生时,ASL的位置显著靠东,造成了西罗斯海南风减弱,东罗斯海南风加强,西阿蒙森海沿岸东风减弱。而在东阿蒙森海,主要由SAM通过影响ASL的经向位置来影响该区域的风场,SAM负位相时,ASL中心位置靠北会造成东阿蒙森海东风增强。此外,ASL位置的偏移也会造成该区域大气环流的改变,当SAM正位相和拉尼娜事件同时发生时,ASL偏移至西阿蒙森海沿岸,而从南极大陆来的寒冷气流主导了该区域,造成气温异常降低,降幅最大超过3℃。

Influence of the probe-sample interaction on scanning near-field optical microscopic images in the far field

We have studied the influence of probe-sample interaction in a scanning near-field optical microscopy （SNOM） in the far field by using samples with a step structure. For a sample with a step height of - λ/4, the SNOM image contrast between the two sides of the step changes periodically at different scan heights. For a step height of-λ/2, the image contrast remains approximately the same. The probe-sample interaction determines the SNOM image contrast here. The influence of different refractive indices of the sample has been also analysed by using a simple theoretical model.

In situ observation of the dissolution kinetics of Al_(2)O_(3) particles in CaO–Al_(2)O_(3)–SiO_(2) slags using laser confocal scanning microscopy

The dissolution kinetics of Al_(2)O_(3) in CaO-Al_(2)O_(3) SiOslags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 K.The results show that the controlling step during the Al_(2)O_(3) dissolution was the diffusionin molten slag.It was found that the dissolution curves of Al_(2)O_(3) particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al_(2)O_(3) ratio of slag.A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al_(2)O_(3) in slag.Diffusion coefficients of Al_(2)O_(3) in slag were calculated as 2.8×10to 4.1×10m~2/s at the temperature of 1773-1873 K.The dissolution rate of Al_(2)O_(3) increased with higher temperature,CaO/Al_(2)O_(3),and particle size.A new model was shown to be v_(Al_(2)O_(3))=0.16×r_(0)^(1.58)×x^(3.52)×(T-T_(mp))^(1.11)to predict the dissolution rate and the total dissolution time of Al_(2)O_(3) inclusions with various sizes,where vAl_(2)O_(3) is the dissolution rate of Al_(2)O_(3) in volume,μm^(3)/s;x is the value of CaO/Al_(2)O_(3) mass ratio;R_(0) is the initial radius of Al_(2)O_(3),μm;T is the temperature,K;T_(mp) is the melting point of slag,K.