Cracking the Snake Detection Theory: The Subcortical Visual Pathway as a Major Player in Cultural Transformations

According to the proposed hypothesis, graphic characters trigger the subcortical visual route. The reaction discussed is very weak. Yet, its very existence has an unusual importance: characters and (occluded) venomous snakeskin patterns reveal themselves as conflatable. Furthermore, following tractogra- phic research, a functional segregation of the subcortical pathway is to be presupposed. Thus, there can’t be a later dissociation of two stimuli previously associated. The outcomes of lecture will gradually appear probabilistically (much) more peaceful than encountering a venomous snake, though, and thus a continuous lessening of the reaction is expectable. Here, on one hand, it is relevant that the subcortical visual pathway goes to the amygdala. The reactions we describe tap into goal-oriented processes, and they will do that unfettered. On the other hand, in the case of characters, since the beginning, fear has been converted into appetition to a great degree. This process should be fostered in the presence of light. In this way, luminosity might become a conditioned stimulus for attraction. In this case, a Pavlovian addiction for light will foster, yet also—from the point of view of reward feeling—counterbalance the lessening of the stimulation elicited by characters. The addiction we refer to is one towards light accompanied by graphic signs. Yet, as opposed to the case of the luminous medium, the attention captured by the later ones taken for themselves is continuously reduced.

Simultaneous determination of three curcuminoids in Curcuma longa L.by high performance liquid chromatography coupled with electrochemical detection

A novel method for analysis of three active components curcumin, demethoxycurcumin and bisdemethoxycurcumin in Curcuma longa L. was developed by HPLC coupled with electrochemical detection. Three curcuminoids were well separated on a C18 column and detected with high sensitivity. A mobile phase containing acetonitrile and 10 mM Na2HPO4-H3PO4 （pH 5.0） （50：50, v/v） was used. Good linearity was obtained in the range of 0.208-41.6, 0.197-39.4, and 0.227-114μM for curcumin, demethoxycurcumin and bisdemethoxycurcumin respectively. The limit of detection reached up to 10 ？ 8 M, which was lower than that by UV detection. The relative standard deviations （RSDs） ranged from 1.06%to 1.88%for intra-day precision and from 4.30%to 5.79%for inter-day precision, respectively. The proposed method has been applied in real herb sample and recoveries ranging from 86.3%to 111%were obtained.

The interaction between a screw dislocation and a wedge-shaped crack in one-dimensional hexagonal piezoelectric quasicrystals

Based on the fundamental equations of piezoelasticity of quasicrystal material,we investigated the interaction between a screw dislocation and a wedge-shaped crack in the piezoelectricity of one-dimensional hexagonal quasicrystals.Explicit analytical solutions are obtained for stress and electric displacement intensity factors of the crack,as well as the force on dislocation.The derivation is based on the conformal mapping method and the perturbation technique.The influences of the wedge angle and dislocation location on the image force are also discussed.The results obtained in this paper can be fully reduced to some special cases already available or deriving new ones.

Feasibility of Trace Alcohol Congener Detection and Identification Using Laser-Induced Breakdown Spectroscopy

In this paper, a feasible scheme is reported for the detection and identification of trace alcohol congeners that have identical elemental composition using laser-induced breakdown spectroscopy （LIBS）. In the scheme, an intensive pulsed laser is used to break down trace alcohol samples and the optical emission spectra of the induced plasma are collected for the detection and identifq ication of alcohol molecules. In order to prepare trace alcohol samples, pure ethanol or methanol is bubbled by argon carrier gas and then mixed into matrix gases. The key issue for the scheme is to constitute indices from the LIBS data of the alcohol samples. Two indices are found to be suitable for alcohol detection and identification. One is the emission intensity ratio （denoted as H/C） of the hydrogen line （653.3 nm） to the carbon line （247.9 nm） for identification and the other is the ratio of the carbon line （as C/Ar） or the hydrogen line （as H/Ar） to the argon lines （866.7 nm） for quantitative detection. The calibration experiment result shows that the index H/C is specific for alcohol congeners while almost being independent of alcohol concentration. In detail, the H/C keeps a specific constant of 34 and 23 respectively for ethanol and methanol. In the meanwhile, the C/Ar and H/Ar indices respond almost linearly to the alcohol concentration below 1300 ppm, and are therefore competent for concentration measurement. With the indices, trace alcohol concentration measurement achieves a limit of 140 ppm using a laser pulse energy of 300 mJ.

Stresses due to an adhesion crack in T-shaped junction of two orthotropic plates

The general solution of stresses is derived for a T-shaped junction of two thin plates with an adhesion crack. The plates are orthotropic. A shear force is applied on the crack surface. The analysis is based on the supposition that the stresses in each plate can be approximated by a plane stress condition. The results obtained are verified by numerical calculation of FEM.

Filtering algorithm of line structured light for long-distance obstacle detection

Since unmanned ground vehicles often encounter concave and convex obstacles in wild ground, a filtering algorithm using line structured light to detect these long distance obstacles is proposed. For the line structured light image, a ranked-order based adaptively extremum median （RAEM） filter algorithm on salt and pepper noise is presented. In the algorithm, firstly effective points and noise points in a filtering window are differentiated; then the gray values of noise points are replaced by the medium of gray values of the effective pixels, with the efficient points＇ gray values unchanged; in the end this algorithm is proved to be efficient by experiments. Experimental resuits demonstrate that the image blur, resulting into proposed algorithm can remove noise points effectively and minimize the protecting the edge information as much as possible.

深部强矿压工作面水力压裂裂纹扩展规律研究

目的为了研究深部强矿压工作面水力压裂裂纹扩展规律,方法以余吾煤矿的3号煤层S5207回风巷为工程背景,首先建立水力压裂力学模型,分析最大周向拉应变准则和裂纹扩展准则,其次通过三维数值模拟,分析水力压裂裂纹扩展影响因子D和地应力对水力压裂裂纹扩展规律的影响,并根据现场情况设计水力压裂试验方案,实施水力压裂增透技术,分析现场施工效果。结果结果表明:预制裂纹沿着与原裂纹呈一定角度开裂并向外延伸,其扩展方向最终与最小主应力方向垂直;随着D增大,裂纹与原裂纹的夹角越来越小,当D较大时,裂纹呈现自相似的扩展状态;不同应力场下,裂纹扩展轨迹主要取决于主应力方向,最终与最小主应力方向垂直,水力裂缝为垂直缝,且在裂纹尖端有应力集中现象;现场监测发现,裂纹扩展符合最大周向拉应变准则,裂纹尖端沿着环向拉应变最大的地方扩展,环向拉应变达到最大时裂纹开始扩展,压裂过程中出现了较大环向裂隙,裂纹沿垂直于最小主应力方向延伸,与S5207回风巷的最大水平主应力方向大致相同,与数值模拟结果接近。结论研究结果可为深部强矿压工作面水力压裂提供参考和依据。

舰船噪声频带级限值线模型的分析与评价

为准确分析舰船声隐身性能的优劣,针对舰船噪声频带级限值线的平折线模型和三点参数模型,推导了在不同噪声控制点参数条件下舰船总声级的频域表达式,以此为基础对舰船噪声源级进行了定量计算,通过数值仿真给出了舰船噪声水平与噪声控制点谱级、控制频点之间的变化规律,并从水声探测的角度出发,研究了舰船噪声频带级限值线模型、声呐品质因素和声呐探测距离之间的依赖关系,分析评价了舰船噪声频带级限值线模型的声隐身性能,以期为舰船的噪声控制方案设计与改进提供依据。

New targets number estimation method under colored noise background

A multiple targets detection method based on spatial smoothing （MTDSS） is proposed to solve the problem of the source number estimation under the colored noise background. The forward and backward smoothing based on auxiliary vectors which are received data on some specific elements is computed. By the spatial smoothing with auxiliary vectors, the correlated signals are decorrelated, and the colored noise is partially alleviated. The correlation matrix formed from the cross correlations between subarray data and auxiliary vectors is computed. By exploring the second-order statistics property of the covariance matrix, a threshold based on Gerschgorin radii of the smoothing correlation matrix is set to estimate the number of sources. Simulations and experimental results validate that MTDSS has an effective performance under the condition of the colored noise background and coherent sources, and MTDSS is robust with the correlated factor of signals and noise.

基于双层聚类信息的极光亚暴自动检测

极光亚暴与太阳风和地球磁场的耦合过程有着紧密的联系,对其发生和发展机制的研究,有助于深入地分析行星际磁场、地球磁层和地球电离层的相互作用,了解太阳风携带的大量能量在地球空间的输运过程,对地球空间环境预警具有重要的意义。Polar卫星搭载的紫外极光图像成像仪能够全天候地获取紫外极光图像,在紫外极光图像中可以完整地展示出极区极光的亮度和尺度变化,尤其是可以清晰地展示出亚暴膨胀相的极光点亮和亮斑膨胀现象。现有的极光亚暴事件检测方法通常需要人工设计特征和相关规则库,耗时耗力。本文利用紫外极光图像提出了基于双层聚类信息的亚暴事件检测方法,实现了紫外极光图像数据中的亚暴事件自动检测。同时,针对极光亚暴事件检测依赖手工设计特征,设计了子空间聚类指导的三维卷积特征自动提取网络;针对极光图像帧间存在成像角度差异,利用地磁纬度和磁地方时信息对极光序列中图像的空间位置进行校正;针对卫星成像位置变化导致的成像噪声,利用极光图像级聚类保留极光亮斑区域和剔除未成像或噪声区域。主观和客观实验结果表明,本算法提升了亚暴事件检测的查全率。

基于改进YOLOv5s的道路裂缝检测算法

为了解决道路巡检系统光学传感器采集的裂缝图像中颜色特征不明显且尺寸不规则造成检测精度不高、泛化能力不足的问题,提出改进YOLOv5s的裂缝检测算法。将结合深度可分离卷积(Depthwise Separable Convolution, DSC)的全局注意力(Global Attention Mechanism, GAM)引入主干特征提取网络,在降低注意力复杂度的同时获得丰富的跨维度特征,增强了裂缝的识别能力;采用空间金字塔软池化网络(Spatial Pyramid Softpool, SPSF),通过Softpool池化保留多维语义以减少信息弥散,提高了边界框回归的准确性;在颈部特征增强网络,运用空洞深度可分离卷积(Atrous DSC)进行下采样,通过扩大感受野加强深层和浅层信息的聚合能力,提高裂缝识别的泛化性。经过在自制道路裂缝数据集上的实验,相较于YOLOv5s,改进算法的mAP提高2.2%,有效提升了道路裂缝检测的准确性和对不同背景下裂缝识别的泛化能力。

光纤超声传感器的射频域自相干解调技术

在光纤光声成像技术中,检测灵敏度是决定光纤超声传感器成像质量的关键性因素之一。以小型化正交双频光纤激光器为超声敏感元件,建立更好的信号解调技术对声致相位变化进行检测,以实现高灵敏度超声检测和光声成像。引入射频域自相干解调技术对超声波引起的激光频率变化进行读取,实验结果表明,该技术具有超声响应信号放大效果,传感器的灵敏度在8~32 MHz的超声频率内获得了显著提升,将最小可检测声压从9.0 Pa降低到5.7 Pa。进一步地,将该超声检测技术应用于活体光声显微成像,发现在同等光强的激发条件下,图像信噪比获得逾4 dB的提升。该技术为光纤光声成像技术的应用拓展奠定了坚实的技术基础。

低空复杂风场全天候雷达精细探测技术

低空复杂风场通常指距离地面高度600 m以下,局地风速、风向快速变化的风场.其全天候大范围精细探测是雷达科学、气象学等领域的长期难题.低空复杂风场的全天候雷达精细探测涉及传感器设计、三维风场反演和全天候融合等关键技术.本文从激光雷达探测、微波雷达探测、全天候融合及特征危害提取等方面对风场探测的技术内涵及研究现状进行了梳理,并分析了发展趋势,为低空复杂风场全天候精细探测技术发展与应用提供参考.

对深度学习中目标定位不确定度评定的讨论

得益于深度学习技术的快速发展,高准确率的目标自动定位得以实现,这为各领域的智能化转型提供了极大的助力。然而,尽管大多数情况下基于深度学习的目标定位方法都能够获得较为精确的输出,但一些误差较大的定位结果还是难以避免。正因为缺少规范的不确定度评定,所以那些误差较大的定位结果难以被有效地消除,进而影响了基于深度学习的目标定位方法的工程化应用。从符合计量规范的测量不确定度入手,讨论了当前深度学习中目标定位技术评价指标的意义和不足,并提出了对规范化目标定位技术不确定度评定的建议。

基于华为鸿蒙的智能路灯控制系统设计

针对传统路灯控制方式缺乏灵活性的问题,文章设计了一种以华为海思Hi3861芯片作为控制核心智能路灯控制系统。本系统通过光照强度传感器检测路灯周围光照强度;根据声音传感器检测路灯周围声音信息,判断是否有车辆经过;利用红外传感器检测行人路过情况。系统搭载华为鸿蒙操作系统,通过MQTT协议将采集到的数据传送到华为云平台,对路灯进行控制,从而降低电能的浪费。实验表明,本系统具有通信稳定可靠、灵活性高、网络支持完善等特点。

基于多视投影的电力杆塔点云绝缘子串快速提取

在无人机自动巡检中,需要根据电力走廊带点云中绝缘子串的位置进行航线规划。由于电力走廊带长度跨越较大,杆塔数量众多,人工进行绝缘子串位置标注的工作量巨大。同时点云数据散乱无序,在三维空间中直接定位绝缘子串耗时长。为此,本文提出多视二维投影,快速提取三维杆塔点云中的绝缘子串。该方法首先利用鲁棒主成分分析,在俯视图中分析杆塔顶端横担水平方向,统一杆塔点云的朝向。接着,在侧视图中通过霍夫直线检测,对电力线高度进行快速定位,并根据电力线与横担的空间关系,将相应的绝缘子串分为顶层悬挂、竖直绝缘子串与水平绝缘子串三类。最后,在多视投影中进行角点检测,对绝缘子串与电力线、杆塔的连接端点进行定位,实现快速的绝缘子串提取。本文提出的方法在50 km的电力走廊带中的97座不同类型杆塔的867个绝缘子串上进行了提取实验,证明了该方法能对不同类型绝缘子串进行快速提取。

深度学习技术在地震储层预测中的应用及挑战

传统地震储层预测技术已无法满足储层精细评价的需求,深度学习具有强大的特征提取和高维数据处理能力,近年来广泛应用于地震储层预测并取得了较好的效果。为此,本文深入讨论深度学习技术在地震储层预测中的应用、进展及它在实际工作中面临的挑战,并提出未来的发展方向。主要认识有:(1)在烃类定性检测方面,深度学习技术有助于综合利用多属性地震数据去提高效率和预测结果的准确率;在定量预测方面,深度学习技术可以更精准地逼近地震数据与目标之间复杂的非线性关系,实现储层的精细定量评价。(2)深度学习技术的应用面临的挑战主要是标签数据不足和样本不均衡等容易导致模型过拟合,泛化能力差;模型复杂,计算成本高;模型的“黑匣子”特征使预测结果缺乏物理可解释性;缺乏定性预测模型的评价标准和高精度的不确定性量化算法。(3)未来的研究方向应致力于克服数据可用性的不足和深度学习的局限性等,构建地球物理知识图谱,实现多源数据与知识的有效融合、共享,将深度学习与反馈强化学习等其他机器学习算法相结合,为油气勘探和开发提供更可靠的技术支撑。

一种基于光学的水表面微波跨介质探测方法

水下声信号的传播和探测研究主要集中在散射、反射和传播损失等方面,而对其在水面引起的波动关注较少。本文在理论上推导了在水下平面波入射在水-空气界面激励的水表面微波与声源强度和频率的关系。这种水表面微波的振幅在纳米级别,振动频率和水下平面波的频率相同,在水-空气界面的扩散距离则随频率的升高而强烈衰减。基于水表面微波的特性,结合激光探测的工作原理,设计了一套跨介质水下目标检测系统。并为该系统可能受到的低频海浪噪声干扰和反射干扰提供了应对方式。仿真结果表明:该系统分辨率高,具有隐蔽性、易于维护性、无接触性等特点,对低频声源的检测效果较好。该方法结合了声波在水中和光波在空气中传播各自的优点,有望成为水下目标检测的一种新手段。

软岩大巷围岩裂隙演化机制与控制研究

本文以南岭煤业52采区进风大巷为研究对象,剖析了软岩大巷变形破坏特点及裂隙演化机制,以期有效解决软岩大巷面临的剧烈变形、失稳等工程难题。首先,根据软弱岩体应力-应变关系,及其与围岩强度变化之间的相互作用关系,构建了能够描述圆形巷道破坏分区现象的力学模型,明晰了软岩大巷围岩弹塑性变形分区破坏特征,揭示了深井软岩大巷围岩的变形破坏机理。其次,基于UDEC-Trigon方法,构建了符合工程尺度的离散元数值计算模型,并提出了针对该模型的参数校正方法。通过模拟研究,探讨了软岩大巷围岩的裂隙扩展特征、应力分布规律、巷道变形规律。最后,提出了深浅部注浆与高强高预紧力锚杆索支护的软岩大巷控制技术及相应参数,并在南岭煤业52采区进风大巷成功应用。应用结果表明:锚杆索+注浆联合控制技术有效控制了52采区进风大巷的变形量,提高了巷道稳定性。本文研究成果为软岩大巷围岩变形稳定控制提供了理论依据和技术支撑。

食品中黄曲霉毒素M_(1)的间接竞争酶联免疫法的建立

该文建立一种间接竞争酶联免疫法(indirect competitive enzyme-linked immunosorbent assay,ic-ELISA)快速测定食品中黄曲霉毒素M_(1)(aflatoxin M_(1),AFM_(1))的分析方法。AFM_(1)标准品用甲醇稀释,AFM_(1)标准品与AFM_(1)全抗原竞争结合AFM_(1)单克隆抗体,利用3,3′,5,5′-四甲基联苯胺(3,3′,5,5′-tetramethylbenzidine,TMB)单组分显色液显色后,酶标仪测定吸光度。在优化好的条件下,浓度范围为9.743~2.605×10^(3)pg/mL时具有良好的线性关系,相关系数(determination coefficient,R^(2))为0.9927,检出限IC_(10)为3.84 pg/mL,加标回收率为88.43%~105.75%。该方法适用性好、操作简单、灵敏度高,满足食品中AFM_(1)分析检测的需求。