基于DSM的城市公园对PM_(2.5)和PM_(10)的消减特征研究——以南昌市人民公园为例

【目的】PM_(2.5)、PM_(10)等空气颗粒物是城市空气首要污染物,在城市空气污染中占主导地位。了解固定外源下PM_(2.5)、PM_(10)在城市绿地的消减特征,可为城市阻控空气颗粒物、缓解空气污染提供有利依据。然而目前空气颗粒物的研究大多以点测定方式量化空间结构及植被类型对空气颗粒物的影响,对固定外源污染下PM_(2.5)、PM_(10)在城市绿地空间尺度上的影响机制研究较少。【方法】研究结合DSM与地统计学,以南昌市人民公园为例,探索城市公园阻隔外源污染的空间梯度效应及空间结构类型差异。利用克里金插值法对其空间分布特征进行可视化模拟;利用Arcgis和R语言等软件分析不同空间结构PM_(2.5)、PM_(10)的浓度差异。【结果】人民公园PM_(2.5)、PM_(10)的浓度在空间分布上趋势一致,均表现为以固定外源点为核心,浓度随距离增加呈极显著梯度递减的趋势,且在中部(约距外源点150~220 m处)消减效率最高,约为全园PM_(2.5)平均消减值的7.5倍,PM_(10)平均消减值的3.8倍;PM_(2.5)、PM_(10)受多种因子影响:与空气温度、距离(主导因子)显著负相关、与相对湿度显著正相关,且PM_(2.5)、PM_(10)对不同因子响应特征存在差异;城市公园不同绿地空间结构对PM_(2.5)、PM_(10)的消减及扩散作用差异显著,受其双重影响,PM_(2.5)、PM_(10)的浓度表现为水体>广场>树林>草坪,其中PM_(2.5)受影响更显著;此外,受各因子和绿地空间结构耦合影响,部分区域PM_(2.5)、PM_(10)分布异常。【结论】以固定外源点为核心,PM_(2.5)、PM_(10)浓度随距离增加呈极显著梯度递减的趋势,且在中部消减效率最高;PM_(2.5)、PM_(10)浓度与相对湿度显著正相关,与空气温度与距离显著负相关,其中PM_(10)对距离和相对湿度响应较为明显,而PM_(2.5)受空气温度影响较大;在随距离变化基础上,不同城市绿地空间结构对PM_(2.5)、PM_(10)消减和扩散作用差异导致了局部分布差异。

亚米级宽幅卫星边缘视场影像的DSM生成研究

宽幅卫星影像常用于小侧摆角条件下拍摄制作大面积的正射影像成果,针对其具有大视场角的特点,提出了大视场角边缘视场结合小侧摆角构建立体像对制作DSM成果的方案。方案分析了宽幅卫星影像特点,选取边缘视场标准景分幅影像结合拍摄侧摆角构建卫星立体像对,阐述了数据处理技术流程。通过“吉林一号”宽幅系列卫星影像进行了DSM成果制作实验,并开展了不同太阳高度角条件下拍摄获取的影像制作的DSM成果纹理质量对比实验。实验结果表明,该方案可实现基高比大于0.5的立体条件,并获取高精度DSM成果,精度可满足1∶10000比例尺的DSM制图要求。此外,对比实验表明,太阳高度角越大,DSM成果纹理越清晰。

基于深度学习的DSM林地自动降高研究

将DSM看做单通道图像,林地区域视为空洞区域,将降高视为图像修复过程进行研究。首先利用HRNet-OCR深度学习模型经训练和推理识别林地区域,构建降高模型训练样本与分类信息;然后利用RFRNet深度学习模型经训练和迭代构成自动降高模型,进行自动降高;最后利用高程归一化算法将待降高区域和训练数据统一到同一高程面,同时加入高程值修正,构成最终的自动降高成果。结果表明,深度学习可以实现DSM林地区域的自动降高,且降高结果会形成较多的可替补范围,应用于DEM项目生产。

Influence of substrate effect on near-field radiative modulator based on biaxial hyperbolic materials

Relative rotation between the emitter and receiver could effectively modulate the near-field radiative heat transfer(NFRHT)in anisotropic media.Due to the strong in-plane anisotropy,natural hyperbolic materials can be used to construct near-field radiative modulators with excellent modulation effects.However,in practical applications,natural hyperbolic materials need to be deposited on the substrate,and the influence of substrate on modulation effect has not been studied yet.In this work,we investigate the influence of substrate effect on near-field radiative modulator based onα-MoO_(3).The results show that compared to the situation without a substrate,the presence of both lossless and lossy substrate will reduce the modulation contrast(MC)for different film thicknesses.When the real or imaginary component of the substrate permittivity increases,the mismatch of hyperbolic phonon polaritons(HPPs)weakens,resulting in a reduction in MC.By reducing the real and imaginary components of substrate permittivity,the MC can be significantly improved,reaching 4.64 forε_(s)=3 at t=10 nm.This work indicates that choosing a substrate with a smaller permittivity helps to achieve a better modulation effect,and provides guidance for the application of natural hyperbolic materials in the near-field radiative modulator.

一种多时相卫星影像密集匹配DSM 配准方法

DSM的精确配准是利用不同时相DSM进行变化检测等应用的前提。本文针对多时相卫星影像密集匹配DSM,提出一种DSM配准方法。该方法以刚体变换为转换模型,通过影像匹配方法获取2D同名点对的基础上得到3D同名点对,然后基于粗配准模型参数,采用稀疏ICP的方法,得到精配准模型参数。采用两个时相的卫星影像密集匹配DSM进行实验,实验结果表明,该方法能够有效地实现DSM的精确配准。

实景三维建设中空三加密、DEM、DSM、DOM部分技术探究

以实景三维吉林建设项目为例,阐述空三加密、DSM匹配及修测编辑、DEM修测编辑、DOM制作镶嵌分幅的生产过程,并就生产过程中的一些问题提出解决方法和注意事项,为同类项目的实施提供参考。

天绘二号和资源三号卫星提取DSM精度对比分析

针对国产雷达卫星和InSAR技术提取DSM产品及其精度评价的问题,本文采用天绘二号卫星进行DSM提取实验,在资源三号卫星立体中选取20个检测点对天绘二号卫星提取的DSM进行精度评价,并在房屋建筑区域、植被覆盖区域对2种卫星提取的DSM进行定性和定量对比分析。实验结果表明,天绘二号卫星提取的DSM和资源三号提取的DSM整体效果相当,2种卫星提取的DSM上的高程点,相对于立体选取的检测点的高程中误差分别为1.25 m和0.5 m;在房屋建筑区域、植被覆盖区域,2种数据源提取DSM晕眩效果有差异,选取出的高程点的高程值差异不大,走势基本一致。通过上述实验结果可以得出结论,天绘二号卫星和InSAR技术均可以实现提取DSM产品,其数据精度满足1∶50 000测图要求。

Calcium-sensitive protein MLC1 as a possible modulator of the astrocyte functional state

Astrocytes,the main population of glial cells in the central nervous system(CNS),exert essential tasks for the control of brain tissue homeostasis,supporting neuron and other glial cell activity from the developmental stage to adult life.To maintain the optimal functionality of the brain,astroglial cells are particularly committed to reacting to every change in tissue homeostatic conditions,from mild modifications of the physiological environment,a process called astrocyte activation,to the more severe alterations occurring in pathological situations causing astrocyte reactivity or reactive astrogliosis(Escartin et al.,2021).During these reactive states,astrocytes mount an active,progressive response encompassing morphological,molecular,and interactional remodeling,leading to the acquisition of new functions and the loss of others,whose intensity,duration,and reversibility are dependent on the nature of the stimulus and regulated in a context-specific manner.

Neuropeptide cholecystokinin:a key neuromodulator for hippocampal functions

Spatial memory is crucial for survival within external surroundings and wild environments.The hippocampus,a critical hub for spatial learning and memory formation,has received extensive investigations on how neuromodulators shape its functions(Teixeira et al.,2018;Zhang et al.,2024).However,the landscape of neuromodulations in the hippocampal system remains poorly understood because most studies focus on classical monoamine neuromodulators,such as acetylcholine,serotonin,dopamine,and noradrenaline.The neuropeptides,comprising the most abundant neuromodulators in the central nervous system,play a pivotal role in neural information processing in the hippocampal system.Cholecystokinin(CCK),one of the most abundant neuropeptides,has been implicated in regulating various physiological and neurobiological statuses(Chen et al.,2019).CCK-A receptor(CCK-AR)and CCK-B receptors(CCK-BR)are two key receptors mediating the biological functions of CCK,both of which belong to class-A sevenfold transmembrane G protein-coupled receptors(Nishimura et al.,2015).CCK-AR preferentially reacts to sulfated CCK,whereas CCK-BR binds both CCK and gastrin with similar affinities(Ding et al.,2022).The expression patterns of CCK-AR and CCK-BR are distinct,implying that CCK has various functions in target regions.For instance,CCK-AR is widely expressed in the GI and brain subregions and is hence implicated in the control of digestive function and satiety regulation.Conversely,CCK-BR is abundantly and widely distributed in the central nervous system,which majorly regulates anxiety,learning,and memory(Ding et al.,2022).However,the roles of endogenous CCK and CCK receptors in regulating hippocampal function at electrophysiological and behavioral levels have received less attention.

基于资源三号影像和高分七号影像的DSM自动匹配效果研究与对比

立体遥感影像为高分辨率、高精度数字表面模型(DSM)的自动提取提供了重要的数据来源。本研究利用资源三号遥感影像和高分七号遥感影像,采用测绘生产软件Inpho7.0进行自动匹配DSM,并对匹配结果进行对比分析。实验结果显示,采用Inpho7.0软件匹配的数据,在影像清晰的地方匹配效果较好,在影像质量不好、有阴影或者弱纹理区域的匹配效果较不理想。其中,在沟谷处资源三号与高分七号成果对比,资源三号的整体细节表达较少,晕渲较为光滑,存在粗差、地貌丢失等情况。但在青藏高原地区常年积雪区,资源三号遥感影像匹配效果优于高分七号。因此,在后续的研究生产中,可针对不同场景和地形地貌特点,选择合适的影像进行编辑处理。

基于DSM视域分析的机场新建塔台遮蔽角测量方法

遮蔽角测量是保障机场塔台相关设备安全稳定运行、辅助机场新建塔台选址的重要手段。常规的遮蔽角测量方法主要有实测法和DEM分析法,但常规方法存在观测条件苛刻、数据处理烦琐、成果精度受限等不足之处。本文提出了一种基于DSM视域分析的遮蔽角测量方法,并以广东省某机场新建塔台地形地物遮蔽角测量工程为例进行验证,结果表明该方法的计算精度和实施效率均有了极大的提高,并具备较强的可复制性和推广性。

Exploring the modulatory role of bovine lactoferrin on the microbiome and the immune response in healthy and Shiga toxin‑producing E.coli challenged weaned piglets

Background Post-weaned piglets suffer from F18+Escherichia coli(E.coli)infections resulting in post-weaning diar-rhoea or oedema disease.Frequently used management strategies,including colistin and zinc oxide,have contrib-uted to the emergence and spread of antimicrobial resistance.Novel antimicrobials capable of directly interacting with pathogens and modulating the host immune responses are being investigated.Lactoferrin has shown promising results against porcine enterotoxigenic E.coli strains,both in vitro and in vivo.Results We investigated the influence of bovine lactoferrin(bLF)on the microbiome of healthy and infected weaned piglets.Additionally,we assessed whether bLF influenced the immune responses upon Shiga toxin-producing E.coli(STEC)infection.Therefore,2 in vivo trials were conducted:a microbiome trial and a challenge infection trial,using an F18+STEC strain.BLF did not affect theα-andβ-diversity.However,bLF groups showed a higher relative abundance(RA)for the Actinobacteria phylum and the Bifidobacterium genus in the ileal mucosa.When analysing the immune response upon infection,the STEC group exhibited a significant increase in F18-specific IgG serum levels,whereas this response was absent in the bLF group.Conclusion Taken together,the oral administration of bLF did not have a notable impact on theα-andβ-diversity of the gut microbiome in weaned piglets.Nevertheless,it did increase the RA of the Actinobacteria phylum and Bifi-dobacterium genus,which have previously been shown to play an important role in maintaining gut homeostasis.Furthermore,bLF administration during STEC infection resulted in the absence of F18-specific serum IgG responses.

Light-field modulation and optimization near metal nanostructures utilizing spatial light modulators

Plasmonic modes within metal nanostructures play a pivotal role in various nanophotonic applications.However,a significant challenge arises from the fixed shapes of nanostructures post-fabrication,resulting in limited modes under ordinary illumination.A promising solution lies in far-field control facilitated by spatial light modulators(SLMs),which enable on-site,real-time,and non-destructive manipulation of plasmon excitation.Through the robust modulation of the incident light using SLMs,this approach enables the generation,optimization,and dynamic control of surface plasmon polariton(SPP)and localized surface plasmon(LSP)modes.The versatility of this technique introduces a rich array of tunable degrees of freedom to plasmon-enhanced spectroscopy,offering novel approaches for signal optimization and functional expansion in this field.This paper provides a comprehensive review of the generation and modulation of SPP and LSP modes through far-field control with SLMs and highlights the diverse applications of this optical technology in plasmon-enhanced spectroscopy.

A high-contrast imaging coronagraph for segmented-mirror large aperture telescopes using a spatial light modulator

The primary mirrors of current and future large telescopes always employ a segmented mirror configuration.The small but non-negligible gaps between neighboring segments cause additional diffraction,which restricts the performance of high-contrast coronagraph.To solve this problem,we propose a coronagraph system based on a single liquid crystal spatial light modulator(SLM).This spatial light modulator is used for amplitude apodization,and its feasibility and potential performance are demonstrated using a laboratory setup using the stochastic parallel gradient descent(SPGD)algorithm to control the spatial light modulator,which is based on point spread function(PSF)sensing and evaluation and optimized for maximum contrast in the discovery working area as a merit function.The system delivers a contrast in the order of 10−6,and shows excellent potential to be used in current and future large aperture telescopes,both on the ground and in space.

CHM与DSM相结合的无人机激光雷达单木分割

【目的】提出一种冠层高度模型(CHM)与数字表面模型(DSM)相结合的单木分割方法,以解决无人机激光雷达提取地形坡度较大区域CHM时因树冠形变导致单木分割精度降低的问题。【方法】利用无人机激光雷达数据,在福建省顺昌县洋口林场地形起伏较大的中、高郁闭度杉木人工林中选择中龄林和幼龄林各3块标准地,结合地面实测数据和目视解译方法,对CHM与DSM相结合(优化方法)的4种窗口的局部最大值法的树顶点探测和极值标记的分水岭算法的单木分割进行精度评价,并与仅基于CHM的传统方法的树顶点探测和单木分割进行对比分析。【结果】树顶点探测方面,随着窗口增大,每块样地探测的单木总数量和探测百分比均呈下降趋势;中龄林3块样地的最佳窗口为0.3 m,幼龄林3块样地的最佳窗口为0.2 m,此时6块样地1∶1对应关系的单木数量和生产者精度均最大;在相应最佳窗口条件下,仅基于CHM的局部最大值法因树冠形变存在容易产生单木多树顶点探测现象,传统方法的单木探测百分比高于优化方法,但传统方法的树顶点探测精度低于优化方法。幼龄林的树顶点探测精度高于中龄林,这是因为幼龄林样地冠幅和单木相邻距离更一致,更适应固定窗口的局部最大值法。单木分割方面,优化方法的单木分割精度高于传统方法,幼龄林的单木分割精度高于中龄林。【结论】局部最大值法的树顶点探测和分水岭算法的单木分割直接数据源为DSM,是树冠表面真实起伏状况的反映,没有树冠形变,研究结果为更真实的树顶点和单木树冠边界。CHM与DSM相结合的单木分割方法在中、高郁闭度杉木人工中、幼林中分割精度较高(6块样地探测率r均大于88%,准确率p均大于92%,F得分均大于91%),将该方法集成在ArcGIS模型构建器中,可为精准化、自动化、集成化的无人机激光雷达单木分割应用提供可能。

基于机载毫米波InSAR数据生产DSM及DOM试验研究

针对地形复杂、常年多云雨雾的地区,以及戈壁滩等其它一些困难地区基础测绘数据获取难的问题,本文提出了利用毫米波干涉合成孔径雷达(InSAR)的方法。该方法利用合成孔径雷达技术,通过发射宽带信号获得距离向高分辨率成像;根据雷达和目标之间的相对运动,形成方位向高分辨率成像,从而实现对目标原始回波的“距离-方位”二维高分辨率成像。试验结果表明,利用机载毫米波InSAR技术生产的数字正射影像(DOM)和数字表面模型(DSM),中误差分别为1.482 m和1.405 m,能够满足丘陵地区1∶5 000比例尺的DOM和DSM的精度要求。

Harnessing immunity:Immunomodulatory therapies in COVID-19

An overly exuberant immune response,characterized by a cytokine storm and uncontrolled inflammation,has been identified as a significant driver of severe coronavirus disease 2019(COVID-19)cases.Consequently,deciphering the intricacies of immune dysregulation in COVID-19 is imperative to identify specific targets for intervention and modulation.With these delicate dynamics in mind,immunomodulatory therapies have emerged as a promising avenue for miti-gating the challenges posed by COVID-19.Precision in manipulating immune pathways presents an opportunity to alter the host response,optimizing antiviral defenses while curbing deleterious inflammation.This review article compre-hensively analyzes immunomodulatory interventions in managing COVID-19.We explore diverse approaches to mitigating the hyperactive immune response and its impact,from corticosteroids and non-steroidal drugs to targeted biologics,including anti-viral drugs,cytokine inhibitors,JAK inhibitors,convalescent plasma,monoclonal antibodies(mAbs)to severe acute respiratory syndrome coronavirus 2,cell-based therapies(i.e.,CAR T,etc.).By summarizing the current evidence,we aim to provide a clear roadmap for clinicians and researchers navigating the complex landscape of immunomodulation in COVID-19 treatment.CS Glucocorticoids are among the most widely prescribed drugs with their immune-suppressive and anti-inflammatory effect[84].The current guidelines for the treatment of COVID-19 recommend against the use of dexamethasone or other systemic CS in non-hospitalized patients in the absence of another indication[70].The RECOVERY trial demonstrates the reduced 28-d mortality among hospitalized patients with COVID-19 using dexamethasone compared to the usual standard of care,along with other investigators,such as Ahmed and Hassan[85].The benefit of dexamethasone was seen only among participants receiving either oxygen alone or invasive mechanical ventilation at randomization but not among those receiving no respiratory support at enrollment[85].In a systematic review and meta-analysis,Albuquerque et al[86]showed that in comparison to tocilizumab,baricitinib,and sarilumab are associated with high probabilities of similar mortality reductions among hospitalized COVID-19 concurrently treated with CS.As a result of the absence of SARS-CoV-2-specific antiviral medications,the effectiveness of COVID-19 treatments is reduced.Several COVID-19 therapies are now under investigation.However,the majority of them lack specificity,efficacy,and safety[87].Immunotherapy is a ground-breaking medical treatment that manipulates the immune system to fight diseases.Translational research is rapidly progressing,recognized as a significant breakthrough in 2013[88].Among the immunotherapeutic options for treating COVID-19 are Immunoglobulin,CP,antibodies,mAbs(mAbs),NK cells,T cells,TLR,cytokine therapies and immune modulators.

基于产品DSM自动构建的复杂产品模块划分方法

为了解决复杂机电产品模块划分难度大、计算复杂等问题,提出了一种自动构建产品设计结构矩阵(DSM)的复杂机电产品模块划分方法。该方法通过对三维建模软件进行二次开发实现从产品的装配体模型中获取产品零部件名称以及各零部件之间的空间距离与设定的阈值进行比较从而得到产品DSM。在此基础上引入产品零部件之间的功能相关性并给出取值参考及相关描述,据此获取产品的功能相关性矩阵,结合产品的DSM与零部件的功能相关性矩阵合理分配其权重获得产品零部件综合关联度矩阵;利用层次聚类算法对产品零部件综合关联度矩阵进行聚类分析获得模块聚类树状图,并提出了模块内外聚合度的定义及其计算方法,以模块内外聚合度为衡量指标,围绕最佳模糊聚类数选取多组模块划分数进行合理性综合评价,选取最佳模块划分组作为产品模块划分方案。最后以某企业生产的伐木机产品为例,按照模块划分零部件简化原则将其简化为共76个零部件组成,并对应用上述模块划分方法将其划分成十个模块,验证了该方法的可行性。

基于GF7卫星影像生产DSM数据及精度验证

为减少GF7卫星在基础地理信息数据生产的数据准备工作,本文通过改变地面控制点数量研究GF7卫星影像生产1∶10000 DSM产品最少需要的控制点数量。结果表明,DSM成果精度受控制点数量影响明显,在3~5个地面控制点的约束下,DSM成果可以满足1∶10000数字高程模型的精度要求。研究成果对降低GF7基础测绘产品生产数据依赖和加快数据更新具有一定参考价值。

基于DSM-YOLO v5的无人机航拍图像目标检测

针对传统无人机航拍图像目标检测算法存在漏检率高、检测成功率低、模型体积大等问题,提出一种新的基于深度可分离多头网络结构的目标检测方法DSM-YOLO v5(depthwise separable multiplex YOLO v5)。通过在YOLO v5网络结构上增加一个尺寸为160×160的小目标检测头,并将其与高层网络进行残差连接,以提升小目标检测能力,同时在Conv模块中引入深度可分离卷积算法,将其中的普通卷积替换为深度可分离卷积,能有效减少网络的参数量,降低模型体积。实验结果表明,基于DSM-YOLO v5网络结构的目标检测的mAP@0.5为36.8%,较YOLO v5s提高3.6个百分点,参数量和模型体积较YOLO v5s整体下降21.1%和19.7%,能够有效地应用于无人机航拍图像目标检测任务。