Image potential states mediated STM imaging of cobalt phthalocyanine on NaCl/Cu(100)

The adsorption and electronic properties of isolated cobalt phthalocyanine （CoPc） molecule on an ultrathin layer of NaC1 have been investigated. High-resolution STM images give a detailed picture of the lowest unoccupied molecular orbital （LUMO） of an isolated CoPc. It is shown that the NaC1 ultrathin layer efficiently decouples the interaction of the molecules from the underneath metal substrate, which makes it an ideal substrate for studying the properties of single molecules. Moreover, strong dependence of the appearance of the molecules on the sample bias in the region of relatively high bias （〉 3.1 V） is ascribed to the image potential states （IPSs） of NaCI/Cu（100）, which may provide us with a possible method to fabricate quantum storage devices.

An estimation framework of regional rooftop photovoltaic potential based on satellite remote sensing images

This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic(PV)potential.The required rooftop information is extracted from Gao Fen-7 satellite images.In particular,the rooftop area is obtained using a semantic segmentation network.The azimuth and inclination angles are calculated based on the digital surface model.In addition,to improve the accuracy of the economic evaluation,buildings are divided into commercial and industrial buildings and residential buildings.Based on the difference in the roof inclination,the rooftops can be divided into flat roofs,on which the PV panels are installed with the optimal inclination angle,and sloped rooftops,on which the PV panels are installed in a lay-flat manner.The solar irradiation on the plane-of-array is calculated using the isotropic sky translocation model.Then,the available installed capacity and generation potential of the rooftop PV is obtained.Finally,the net present value,dynamic payback period,and internal rate of return are used to evaluate the economic efficiency of the rooftop PV project.The proposed framework is applied in the Da Xing district of Beijing,China,with a total area of 546.84 km^(2).The results show that the rooftop area and available installed capacity of PV are 25.63 km^(2)and 1487.45 MWp,respectively.The annual rooftop PV generation potential is 2832.23 GWh,with significant economic returns.

Development and validation of a risk model for noninvasive detection of cancer in oral potentially malignant disorders using DNA image cytometry

Objective:To elucidate whether DNA aneuploidy was an independent discriminator for carcinoma within oral potentially malignant disorders(OPMDs),and further establish and validate a risk model based on DNA aneuploidy for the detection of oral cancer.Methods:A total of 810 consecutive patients with OPMD were prospectively enrolled from March 2013 to December 2018,and divided into a training set(n=608)and a test set(n=202).Brushing and biopsy samples from each patient were processed by DNADNA image cytometry and histopathological examination,respectively.Results:DNA aneuploidy of an outside DNA index≥3.5 in OPMD was an independent marker strongly associated with malignant risk[adjusted odds ratio:13.04;95%confidence interval(CI):5.46-31.14].In the training and test sets,the area under the curve(AUC)was 0.87(95%CI:0.82-0.91)and 0.77(95%CI:0.57-0.97),respectively,for detecting carcinoma in OPMD patients.The independent risk factors of lateral/ventral tongue and non-homogenous type combined with a risk model built with a multivariate logistic regression revealed a more favorable diagnostic efficacy associated with the training set(AUC:0.93;95%CI:0.91-0.96)and test set(AUC:0.94;95%CI:0.90-0.98).The sensitivity and specificity of carcinoma detection within OPMD was improved to 100%and 88.1%,respectively.Conclusions:This large-scale diagnostic study established a risk model based on DNA aneuploidy that consisted of a noninvasive strategy with lateral/ventral tongue and non-homogenous features.The results showed favorable diagnostic efficacy for detecting carcinoma within OPMD,irrespective of the clinical and pathological diagnoses of OPMD.Multicenter validation and longitudinal studies are warranted to evaluate community practices and clinical applications.

Point Charges and Conducting Planes for Yukawa’s Potential and Coulomb’s Potential

In this work, we modeled and simulated the electric potential generated by point charges in the region of grounded conductor planes for Yukawa potential (e−μ/r) and Coulomb potential (1/r). We show the symbolic expression for the electric potential and some graphs for it and for the electric field with different values of μ. We observe that the electric potential decreases as the value of μ increases and that does not allow all the charge to be distributed on the surface of the conductor.

Why do stroke patients with negative motor evoked potential show poor limb motor function recovery?

Negative motor evoked potentials after cerebral infarction, indicative of poor recovery of limb motor function, tend to be accompanied by changes in fractional anisotropy values and the cerebral pe-duncle area on the affected side, but the characteristics of these changes have not been reported. This study included 57 cases of cerebral infarction whose motor evoked potentials were tested in the 24 hours after the first inspection for diffusion tensor imaging, in which 29 cases were in the negative group and 28 cases in the positive group. Twenty-nine patients with negative motor evoked potentials were divided into two groups according to fractional anisotropy on the affected side of the cerebral peduncle： a fractional anisotropy 〈 0.36 group and a fractional anisotropy 〉 0.36 group. All patients underwent a regular magnetic resonance imaging and a diffusion tensor imaging examina- tion at 1 week, 1, 3, 6 and 12 months after cerebral infarction. The FugI-Meyer scores of their hemiplegic limbs were tested before the magnetic resonance and diffusion tensor imaging exami-nations. In the negative motor evoked potential group, fractional anisotropy in the affected cerebral peduncle declined progressively, which was most obvious in the first 1-3 months after the onset of cerebral infarction. The areas and area asymmetries of the cerebral peduncle on the affected side were significantly decreased at 6 and 12 months after onset. At 12 months after onset, the area asymmetries of the cerebral peduncle on the affected side were lower than the normal lower limit value of 0.83. FugI-Meyer scores in the fractional anisotropy ≥0.36 group were significantly higher than in the fractional anisotropy 〈 0.36 group at 3-12 months after onset. The fractional anisotropy of the cerebral peduncle in the positive motor evoked potential group decreased in the first 1 month after onset, and stayed unchanged from 3-12 months; there was no change in the area of the cerebral peduncle in the first 1-12 months after cerebral infarction. These findings confirmed that if the fractional anisotropy of the cerebral peduncle on the affected side is 〈 0.36 and the area asym-metries 〈 0.83 in patients with negative motor evoked potential after cerebral infarction, then poor hemiplegic limb motor function recovery may occur.

Simultaneous Measurement of Neural Activities of Acute Mouse Hippocampal Slices Using Multi-Electrode Array System and Laser Confocal Calcium Imaging

Recently, non-invasive, real-time and multi-point measurement of neural activities has become possible by using a multi-electrode array (MEA). Another method for multi-point measurement is the fluorescent imaging technique using voltage indicator dyes or calcium indicator dyes. Especially, calcium imaging using fluorescent calcium indicator dyes is often more useful, because they exhibit larger changes in the fluorescence intensity than voltage indicator dyes and their fluorescence changes can be detect easily. Additionally, calcium signals play key roles in the brain function, such as the long-term potentiation (LTP) in the hippocampus, and calcium imaging can be a powerful tool to elucidate the brain function. In this study, we constructed a measurement apparatus combining the MEA system and laser confocal calcium imaging and simultaneously measured electric signals and calcium signals in acute mouse hippocampal slices. The obtained results showed the availability of the present method.

Point Charge between Two Grounded and Conducting Planes Forming a 60°Angle and for Yukawa’s Potential and Coulomb’s Potential

For a point charge between two grounded conductor planes forming a 60° angle, the potential and electric field generated by point charge for Yukawa’s potential (e-μr/r) and Coulomb’s potential (1/r) are modeled and simulated. The expression for the potential that generalizes the cases discussed in López-Mariño, M. and Trujillo Caballero, J. (2017) Point Charges and Conducting Planes for Yukawa’s Potential and Coulomb’s Potential. Journal of Electromagnetic Analysis and Applications, 9, 135-146. https://doi.org/10.4236/jemaa.2017.910012 is presented. Graphs for the potential and electric field for both cases are showed using Maple, that of Coulomb and that of Yukawa for different values of μ . The purpose of this work is to offer students a practical guide for problem analysis of electrostatics using Maple’s capabilities as a computational tool.

基于脑电信息的图感认知响应规律及其量化分析方法

“图”是人类感知世界的重要媒介,图感认知是大脑认知思维中平面图元与三维形体间形成有效转换的关键通道,但人脑在接受图形输入、完成认知处理并实现知识输出的过程是认知心理学和脑科学交叉学科。目前缺乏充分的研究方法和理论基础,因此针对图感认知过程不清晰及认知分析方法缺乏等问题,根据认知事件的脑电位相关性理论,以二维投影图和三维模型为图感认知对象,设计脑电认知测试实验并分析P300电位变化情况。结果表明:图感认知相关部位主要为大脑的前半部分左额叶位置;P300电位值可以用于反映大脑的图感认知程度,大脑对图像内容的接受能力越强,P300电位峰值越低。对比不同样本P300电位变化,可对图感认知过程进行分析,形成对图感认知能力的量化分析方法,提高图感认知内容对大脑的输入效率,对揭示图感输入和认知机理具有启示意义,并为图像交互深度应用反馈优化提供有效依据。

台风“利奇马”引发山东极端降水过程分析

利用NCEP-GFS再分析资料,对2019年1909号台风“利奇马”8月10-11日在山东产生极端强降水过程展开分析,并与相似路径台风“安比”进行对比,结果表明:强辐合区和急流的长期维持是极端强降水的直接原因。风场和温度场的不对称性有利于暖湿气流在山东中部长期维持。冷暖平流在山东中部即台风倒槽处交汇,导致台风倒槽内锋生函数的大值区长期维持。冷空气从台风的西侧和南侧侵入,并没有很快破坏台风东北侧气流的暖湿特性。水汽图像能直观地反映出冷空气向东侵入的连续过程。850 hPa水汽通量强辐合区集中在山东中部,为极端降水的出现提供水汽条件。相似路径台风“安比”风场辐合中心强度、锋生强度、水汽通量辐合中心强度远不及“利奇马”的强度,这些都导致类似“安比”的一般台风过程造成山东的降水强度远弱于“利奇马”造成的降水强度。

FY-4A数据在2021年1月6—8日寒潮监测中应用

基于静止气象卫星图像解译理论和位涡理论,应用FY-4A水汽图像、干涉式大气垂直探测仪(GIIRS)产品和欧洲中心第五代大气再分析资料(ERA5)对2021年1月6—8日我国中东部地区寒潮天气进行分析。结果表明:高空冷涡和地面冷高压是影响此次寒潮天气的主要影响系统,冷空气5日08:00从贝加尔湖南部向东、向南加强发展,8日20:00减弱;对比FY-4A/GIIRS与ERA5850 hPa 24 h变温数据发现:两种数据反映的对流层低层冷空气东移南下特征和正负变温区域分布特征基本一致,FY-4A/GIIRS 850 hPa 24 h负变温中心和0℃等变温线的位置与ERA5数据接近,FY-4A/GIIRS 850 hPa 24 h变温中心值强度略大于ERA5。水汽图像暗区变暗附近的高层位涡的增加激发高层气旋性环流后侧下沉运动增强,干空气下沉造成了地面高压增强;500 hPa冷涡中心附近绝对涡度增加是引起冷空气增强的原因之一;冷空气急剧增强时段,中低层位涡的加大引起地面冷空气堆积,寒潮增强。FY-4A/GIIRS温度产品反映的冷空气移动特征与位涡理论对冷空气增强原因分析结果一致,说明应用FY-4A/GIIRS温度产品能够有效监测分析寒潮冷空气演变特征。

时差成像技术和人工智能在ART治疗中的应用

准确评估胚胎发育对于辅助生殖技术(ART)成功至关重要。传统方法多基于主观的胚胎形态学评估,缺乏客观性和实时性。时差成像技术(TLT)提供更稳定的培养环境,实现胚胎发育的动态监测,分析和建模不同发育时期的动态学参数,用于预测胚胎的植入潜力。然而,动态学参数通常需要人工标注,引入主观干扰,数据模型分析能力差异较大,与实际情况相差甚远,尤其在染色体整倍性分析方面表现较弱。随着人工智能(AI)的不断发展,TLT与AI的结合提供了减少TLT人工标注时间、提高胚胎植入率和染色体整倍性预测等方面的可能性。旨在探讨TLT结合AI在形态学和动态学参数方面对胚胎植入潜力和染色体整倍性的应用。

基于镜像原理的田间暗管排水流量计算方法

针对目前尚无适宜的计入复合型外包滤料影响的暗管排水流量计算方法,结合渗流力学中的镜像法和势流叠加原理,以宁夏银北灌区冬灌洗盐为背景,提出一种田面积水土壤饱和条件下考虑外包滤料影响的暗管流量公式.通过室内渗流槽试验和HYDRUS-2D软件模拟确定相关水力特征参数,将试验数据、数值模拟和努美罗夫解与文中计算公式进行了对比分析,结果表明:公式计算值与渗流槽试验数据、数值模拟值的相对误差分别在7.00%及2.05%以内;当外包滤料厚度小于15 cm时,计算值及引入有效半径概念的努美罗夫解与模拟值有较高吻合度;当外包滤料厚度大于15 cm时,计算值与数值模拟值更接近,并且优于努美罗夫解;暗管的排水流量随外包滤料渗透系数或厚度的增加而逐渐增大,但增长率逐渐变缓.基于镜像法提出的考虑复合外包滤料影响的田间暗管排水流量计算公式合理可行,拓展了暗管排水计算思路.

基于外部先验和自先验注意力的图像描述生成方法

图像描述是一种结合计算机视觉和自然语言处理的跨模态任务,旨在理解图像内容并生成恰当的句子。现有的图像描述方法通常使用自注意力机制来捕获样本内的长距离依赖关系,但这种方式不仅忽略了样本间的潜在相关性,而且缺乏对先验知识的利用,导致生成内容与参考描述存在一定差异。针对上述问题,文中提出了一种基于外部先验和自先验注意力(External Prior and Self-prior Attention, EPSPA)的图像描述方法。其中,外部先验模块能够隐式地考虑到样本间的潜在相关性进而减少来自其他样本的干扰信息。同时,自先验注意力能够充分利用上一层的注意力权重来模拟先验知识,使其指导模型进行特征提取。在公开数据集上使用多种指标对EPSPA进行评估,实验结果表明该方法能够在保持低参数量的前提下表现出优于现有方法的性能。

Cu^(2+)污染原状黄土的物化及结构特性

为制定环境保护和土壤污染防治和修复策略,以及为污染场地工程建设提供理论支撑,该文研究了Cu^(2+)对原状黄土物化特性及结构特性的影响。通过制备不同掺量的Cu^(2+)污染黄土试样,进行了粒径分布、CaCO_(3)含量和pH值的测定。利用扫描电镜和激光粒度仪获得试样的SEM图像和粉粒各粒径含量,并借助分形理论深入分析了Cu^(2+)对原状黄土微观结构的影响机理。对Cu^(2+)污染的原状黄土试样进行了压缩试验,并对试样的综合结构势进行了分析。结果表明,随着Cu^(2+)掺量的增大,黏粒含量表现为先增后减,再增再减的趋势,粉粒含量则表现为先减后增,再减再增,砂粒含量保持不变;CaCO_(3)的含量呈线性减小;pH值先迅速减小,后保持不变;污染黄土试样的综合结构势先增大后减小,之后再增大再减小。总体而言,重金属Cu^(2+)的掺入,导致土壤pH值降低,主要胶结物质碳酸钙被溶解,而又因黏粒之间的静电引力和范德华力,黏粒聚集体的形态和成分发生变化,从而影响了土体的密实度和结构强度。

借助弱纹理匹配的TEDS车底故障区域定位算法

针对当前动车组运行故障动态图像检测系统(trouble of moving EMU detection system,TEDS)故障识别准确率低的问题,本文提出一种借助弱纹理匹配的动车底部潜在故障区域定位方法。首先,采用拓扑交叉数检测大量弱纹理区域特征点;然后,以特征点为中心的环形区域内各像素点的拓扑交叉数值筛选特征点,构建相应特征向量进行弱纹理特征匹配;最后,对配准后的图像进行比对定位潜在故障区域。实验结果表明,该算法保证了匹配精度,能检测出大部分潜在故障区域,弱纹理区域的特征匹配准确率超过80%且所有图像对均存在特征匹配对,为以后的精准故障分类提供了有利条件。

寻找时间的时间——论洪尚秀电影中的时间晶体

在洪尚秀导演的电影创作中,作为主体内意识的时间与电影的内外现实、艺术真实、诗意体验相交融,并通过时间-影像中潜在影像与现实影像不断的对称、循环、结晶而成功构建出独特的时间晶体。其中,时间的本质涌现,新的生命真实也得以显现。在以影像内部的时间寻找非时序时间即纯粹时间与本真性生命存在的过程中,时间-影像不断使宇宙时空成为绵延的微观海洋,亦成为主体深层生命体验下的真实场域。在反中心、非线性、去权力的影像世界中,个体打开无限、自由、创造性的全部潜能,从而在世界中显现自身,最终达到存在的澄明。

城市快速路光伏声屏障安装潜力研究

光伏声屏障(PVNB)将光伏发电模块集成到道路声屏障中,在实现隔声的同时,为城市交通系统产生清洁电力。以城市高架和高速公路为应用场景,提出了一种量化光伏声屏障系统大规模部署潜力的方法,运用图像识别与地理信息系统结合的方式,探讨在城市中推广光伏声屏障的可行性。研究结果表明,在闵行区6个交通枢纽上已安装的声屏障总长约35 km,总计34个路段。若在这些路段中安装光伏,则其方位角较大并呈正值,主要朝西。若用双面光伏垂直安装取代声屏障中段部分,则其等效峰值日照数达到2.76 h,全年发电量可达620万kWh。此评估方法可为后续大空间尺度预测光伏发电潜力和交通场景中光伏应用的实际操作提供有力的参考和指导。

多种物探方法在昌吉硫磺沟地区煤田火烧区勘查中的应用研究

煤层自燃不仅影响周边生态环境,也存在较大的安全隐患。以昌吉硫磺沟地区为例,根据煤层自燃所产生的物理化学变化与周围岩石产生的物性差异,运用无人机红外成像、无人机航空磁测和自然电位法开展勘查,通过对三种方法的成果分析与解译,圈定煤田火烧区的范围,为后期治理等工作提供基础资料。

Motor imagery training induces changes in brain neural networks in stroke patients

Motor imagery is the mental representation of an action without overt movement or muscle activation. However, the effects of motor imagery on stroke-induced hand dysfunction and brain neural networks are still unknown. We conducted a randomized controlled trial in the China Rehabilitation Research Center. Twenty stroke patients, including 13 males and 7 females, 32–51 years old, were recruited and randomly assigned to the traditional rehabilitation treatment group（PP group, n = 10） or the motor imagery training combined with traditional rehabilitation treatment group（MP group, n = 10）. All patients received rehabilitation training once a day, 45 minutes per session, five times per week, for 4 consecutive weeks. In the MP group, motor imagery training was performed for 45 minutes after traditional rehabilitation training, daily. Action Research Arm Test and the Fugl-Meyer Assessment of the upper extremity were used to evaluate hand functions before and after treatment. Transcranial magnetic stimulation was used to analyze motor evoked potentials in the affected extremity. Diffusion tensor imaging was used to assess changes in brain neural networks. Compared with the PP group, the MP group showed better recovery of hand function, higher amplitude of the motor evoked potential in the abductor pollicis brevis, greater fractional anisotropy of the right dorsal pathway, and an increase in the fractional anisotropy of the bilateral dorsal pathway. Our findings indicate that 4 weeks of motor imagery training combined with traditional rehabilitation treatment improves hand function in stroke patients by enhancing the dorsal pathway. This trial has been registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-OCH-12002238）.

成年小鼠触液神经元体外分离培养及自我更新能力的鉴定

背景:课题组前期成功在体外分离培养乳鼠触液神经元,尚无研究报道有效分离培养高纯度成年小鼠触液神经元的方法,且触液神经元的自我更新能力是否随着年龄发生变化尚无研究。目的:建立一种高纯度成年小鼠触液神经元体外分离培养的方法,并鉴定成年小鼠触液神经元与乳鼠触液神经元在体外的自我更新能力。方法:从成年3月龄小鼠颈髓分离含有触液神经元的原代细胞贴壁培养并利用融合多模态成像基因的慢病毒转染细胞,通过嘌呤霉素筛选得到高纯度成年小鼠触液神经元细胞,在完全培养基中悬浮培养。通过免疫荧光检测成年小鼠触液神经元表达神经干细胞标记物巢蛋白(Nestin)及SOX2情况,观察成年小鼠触液神经元体外成球与传代能力;将同等数量(5×10^(3))的第3代成年小鼠及乳鼠触液神经元在同等条件下分为2组,分别接种在含有完全培养基的超低黏附培养板中,在体积分数5%CO_(2),37℃恒温箱悬浮培养,通过体外成球、CCK8实验、qPCR和Western blot鉴定成年小鼠及乳鼠触液神经元的自我更新能力。结果与结论:①实验成功在成年小鼠体内分离出高纯度触液神经元,在体外表达Nestin及SOX2,能形成神经球并连续传代。②成年小鼠触液神经元体外自我更新能力较乳鼠相比明显减弱,细胞培养到第4天时乳鼠触液神经元已经形成直径约为150μm的神经球,而成年小鼠触液神经元所形成的神经球直径仅为40μm(P<0.0001)。③CCK8增殖实验结果表明,成年小鼠触液神经元的增殖活性在培养后各时间点显著弱于乳鼠(P<0.0001)。④qPCR和Western blot检测发现成年小鼠触液神经元Nestin及SOX2的mRNA(P<0.0001)和蛋白表达量(P<0.01)较乳鼠显著下降。⑤上述结果证实,成年小鼠触液神经元的体外自我更新能力显著弱于乳鼠。