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%。

Quantum Anomalous Hall Effect with Tunable Chern Numbers in High-Temperature 1T-PrN_(2) Monolayer

Quantum anomalous Hall(QAH) insulators have highly potential applications in spintronic device. However,available candidates with tunable Chern numbers and high working temperature are quite rare. Here, we predict a 1T-PrN_(2) monolayer as a stable QAH insulator with high magnetic transition temperature of above 600 K and tunable high Chern numbers of C = ±3 from first-principles calculations. Without spin-orbit coupling(SOC),the 1T-PrN_(2) monolayer is predicted to be a p-state Dirac half metal with high Fermi velocity. Rich topological phases depending on magnetization directions can be found when the SOC is considered. The QAH effect with periodical changes of Chern number(±1) can be produced when the magnetic moment breaks all twofold rotational symmetries in the xy plane. The critical state can be identified as Weyl half semimetals. When the magnetization direction is parallel to the z-axis, the system exhibits high Chern number QAH effect with C = ±3.Our work provides a new material for exploring novel QAH effect and developing high-performance topological devices.

Orbital-Ordering Driven Simultaneous Tunability of Magnetism and Electric Polarization in Strained Monolayer VCl_(3)

Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).

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.

Factors resisting protein adsorption on hydrophilic/hydrophobic self-assembled monolayers terminated with hydrophilic hydroxyl groups

The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.

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。

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℃。

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）.

Self-Assembled Monolayers (SAMs): Which Perspectives in Implant Dentistry?

Self-assembled monolayers (SAMs) are ordered organic films formed by adsorption of an active organic coating on a solid surface. Their formation provides an alternative, highly innovative, to current traditional chemical treatments of the titanium surfaces. For this reason the structural phases, the formation and the growth of SAMs is described from a surface science point of view. Particulars are given to SAMs on titanium concerning surface morphology, chemical composition and affinity of specific head group for Ti surfaces (silanes, siloxane, phosphonates and phosphates). Preparation, coating methodologies, limitations and techniques used for the characterization of SAMs are reported. For their physicochemical characteristics and micro-nano scale features some perspectives of using SAMs in biomedical application are outlined.

Monolayer MoS_(2)Fabricated by In Situ Construction of Interlayer Electrostatic Repulsion Enables Ultrafast Ion Transport in Lithium-Ion Batteries

High theoretical capacity and unique layered structures make MoS_(2)a promising lithium-ion battery anode material.However,the anisotropic ion transport in layered structures and the poor intrinsic conductivity of MoS_(2)lead to unacceptable ion transport capability.Here,we propose in-situ construction of interlayer electrostatic repulsion caused by Co^(2+)substituting Mo^(4+)between MoS_(2)layers,which can break the limitation of interlayer van der Waals forces to fabricate monolayer MoS_(2),thus establishing isotropic ion transport paths.Simultaneously,the doped Co atoms change the electronic structure of monolayer MoS_(2),thus improving its intrinsic conductivity.Importantly,the doped Co atoms can be converted into Co nanoparticles to create a space charge region to accelerate ion transport.Hence,the Co-doped monolayer MoS_(2)shows ultrafast lithium ion transport capability in half/full cells.This work presents a novel route for the preparation of monolayer MoS_(2)and demonstrates its potential for application in fast-charging lithium-ion batteries.

Nonlinear Photocurrent Responses in Janus WSSe Monolayer

Janus WSSe monolayer is a novel two-dimensional(2D)material that breaks the out-of-plane mirror symmetry and has a large built-in electric field.These features lead to sizable Rashba spin-orbit coupling and enhanced nonlinear optical properties,making it a promising material platform for various spintronic and optoelectronic device applications.In recent years,nonlinear photocurrent responses such as shift and injection currents were found to be closely related to the quantum geometry and Berry curvature of materials,indicating that these responses can serve as powerful tools for probing the novel quantum properties of materials.In this work,we investigate the second-order nonlinear photocurrent responses in a Janus WSSe monolayer theoretically based on first-principles calculations and the Wannier interpolation method.It is demonstrated that the Janus WSSe monolayer exhibits significant out-of-plane nonlinear photocurrent coefficients,which is distinct from the nonJanus structures.Our results also suggest that the second-order nonlinear photocurrent response in the Janus WSSe monolayer can be effectively tuned by biaxial strain or an external electric field.Thus,the Janus WSSe monolayer offers a unique opportunity for both exploring nonlinear optical phenomena and realizing flexible 2D optoelectronic nanodevices.

Coexistence of Zero-Dimensional Electride State and Superconductivity in AlH_(2)Monolayer

Elect rides,which confine"excess anionic electrons"in subnanometer-sized cavities of a lattice,are exotic ionic crystals.We propose a non-stoichiometric strategy to realize intrinsic two-dimensional(2D)superconducting elect ride.AlH_(2)monolayer,which is structurally identical to 1H-MoS_(2),possesses zero-dimensionally confined anionic electrons in the interstitial sites of A1 triangles,corresponding to a chemical formula of[AlH_(2)]^(+)e^(-).The interaction between interstitial anionic electrons(IAEs)and host cation lattice mainly accounts for stabilization of 1H-AlH_(2)electride.Impressively,1H-AlH_(2)monolayer is an intrinsic Bardeen-Cooper-Schrieffer superconductor with T_(c)=38 K,which is the direct consequence of strong coupling of the H-dominated high electronic states with Al acoustic branch vibrations and mid-frequency H-derived phonon softening modes caused by Kohn anomalies.Under tensile strain,IAEs transform into itinerant electrons,favoring the formation of stable Cooper pairs.Therefore,T_(c)reaches up to 53 K at a biaxial fracture strain of 5%.Our findings provide valuable insights into the correlation between non-stoichiometric electrides and superconducting microscopic mechanisms at the 2D limit.

Ambipolar Doping of Monolayer FeSe by Interface Engineering

We report on ambipolar modulation doping of monolayer FeSe epitaxial films grown by molecular beam epitaxy and in situ spectroscopic measurements via a cryogenic scanning tunneling microscopy.It is found that hole doping kills superconductivity in monolayer FeSe films on metallic Ir(001)substrates,whereas electron doping from polycrystalline IrO_(2)/SrTiO_(3)substrate enhances significantly the superconductivity with an energy gap of 10.3 meV.By exploring substrate-dependent superconductivity,we elucidate the essential impact of substrate work functions on the superconductivity of monolayer FeSe films.Our results therefore offer a valuable reference guide for further enhancement of the transition temperature Tc in FeSe-based superconductors by interface engineering.

Large-Area Monolayer n-Type Molecular Semiconductors with Improved Thermal Stability and Charge Injection

We fabricated monolayer n-type two-dimensional crystalline semiconducting films with millimeter-sized areas and remarkable morphological uniformity using an antisolvent-confined spin-coating method.The antisolvent can cause a downstream Marangoni flow,which improves the film morphologies.The deposited crystalline monolayer films exhibit excellent thermal stabilities after annealing,which reveals the annealing-induced enhancement of crystallinity.The transistors based on the n-type monolayer crystalline films show linear output characteristics and superior electron mobilities.The improved charge injection between monolayer films and Au electrodes results from the energy level shift as the films decrease to the monolayer,which leads to a lower injection barrier.This work demonstrates a promising method for fabricating air-stable,low-cost,high-performance,and large-area organic electronics.