Typhoon vs. cold wave: a comparative assessment of geomorphic response and boulder displacement using RFID technology

Extreme storm events in coastal zones play significant roles in shaping the morphology of boulder beaches.However,boulder displacement and the geomorphological evolution of boulder beaches driven by different extreme storm events,especially typhoon events,remain poorly understood.Thus,boulder displacement and the geomorphic response on a boulder beach in Fujian,southeastern China,were explored before,during and after a cold wave event(Dec.1–7,2020)and before and after Typhoon In-Fa(Jul.19–27,2021),a large tropical storm.This was achieved by tracking 42 tagged boulders distributed in the intertidal and supratidal zones using Radio Frequency Identification(RFID)and topographic surveys using real-time kinematic techniques,respectively.The results showed obvious disparities in boulder displacement in different geomorphic zones due to cold wave and typhoon events that were mainly characterized by migration magnitude,range,direction,and mode of transport.The typhoon event led to rapid and substantial changes in the overall morphology of the boulder beach,while the cold wave event impacted the intertidal morphology of the boulder beach to only a small extent.The surrounding structure of boulders,beach slope and beach elevation had a combined dominant effect on boulder displacement under the same extreme event.Hydrodynamic factors(effective wave energy fluxes,incident wave direction,storm surge and water level)had dominant effects on boulder displacement during different extreme events.In terms of a single event,the magnitude of the boulder displacement driven by the typhoon was much greater than that driven by the cold wave.However,considering the frequency and duration of cold waves in winter,the impact of multiple consecutive cold waves on the geomorphology of the boulder beach cannot be ignored in this study area.Alternating and repeated interactions between these two processes constitute the complete geomorphic evolution of the boulder beach.This study contributes to improved predictions of the morphodynamic response of boulder beaches to future storms,especially large tropical storms,and facilitates better coastal management.

Review of Electronic Speckle Pattern Interferometry(ESPI) for Three Dimensional Displacement Measurement

Three dimensional（3D） displacements, which can be translated further into 3D strain, are key parameters tor design, manufacturing and quality control. Using different optical setups, phase-shift methods, and algorithms, several different 3D electronic speckle pattern interferometry（ESPl） systems for displacement and strain measurements have been achieved and commercialized. This paper provides a review of the recent developments in ESPI systems for 3D displacement and strain measurement. After an overview of the fundamentals of ESP! theory, temporal phase-shift, and spatial phase-shift techniques, 3D deformation measurements by the temporal phase-shift ESPI system, which is suited well for static measurement, and by the spatial phase-shift ESPI system, which is particularly useful for dynamic measurement, are discussed. For each method, the basic theory, a brief derivation and different optical layouts are presented. The state of art application, potential and limitation of the ESPI systems are shown and demonstrated.

Displacement map技术在角色面部细节渲染中的研究与使用

Displacement map技术是将模型的顶点进行偏移,实现真实的面凹凸效果,能更好地在低精度模型上表现出高精度模型细节,最终达到所需的渲染效果。但由于Displacement map制作方法很多,在Maya arnold渲染器中使用Displacement map进行角色渲染时,经常不能控制渲染效果,导致角色过于肿胀或者面发生反转,尤其要在渲染中将同一角色的面部结构以及粗、较粗、细腻3种皮肤纹理细节有机结合表现出来,就更加困难。本文针对以上问题,提出了使用Maya中的ramp节点、plusMinusAverage节点、multiplyDivide节点,对Displacement map中包含3种皮肤纹理信息的RGB通道分别进行转换和控制的方法。并对该方法进行测试,证明方法的可行性。

Comparison of oil displacement mechanisms and performances between continuous and dispersed phase flooding agents

To compare the oil displacement mechanisms and performances of continuous phase flooding agent(traditional polymer solution) and dispersed phase flooding agent(particle-type polymer SMG dispersion), the particle phase separation of SMG dispersion migrating in pores was simulated by using the microfluidic technology. Theoretically guided by the tree fork concentration distribution of red cells in biological fluid mechanics, the concentration distribution mathematical model of SMG in different pores is established. Furthermore, the micro and macro physical simulation experiments of continuous and dispersed phase flooding agents were carried out. The results show that the continuous flooding agent enters all the swept zones and increases the flow resistance in both larger and small pores. On the contrary, the particle phase separation phenomenon occurs during the injection process of dispersed flooding agent. The SMG particles gather in the larger pore to form bridge blinding, and the carrier fluid displace oil in the small pore. Working in cooperation, the SMG particle and carrier fluid drive the residual oil in the low permeability layers step by step and achieve the goal of enhanced oil recovery. The laboratory experimental results indicate that, the oil increment and water reduction effect of dispersed flooding agent is much better than that of continuous flooding agent, which is consistent with the field test results.

Analysis of displacement damage effects on the charge-coupled device induced by neutrons at Back-n in the China Spallation Neutron Source

Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradiation experiment.The hot pixels,random telegraph signal(RTS),mean dark signal,dark current and dark signal non-uniformity(DSNU)induced by Back-n are presented.The dark current is calculated according to the mean dark signal at various integration times.The single-particle displacement damage and transient response are also observed based on the online measurement data.The trends of hot pixels,mean dark signal,DSNU and RTS degradation are related to the integration time and irradiation fluence.The mean dark signal,dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation.In addition,the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design(TCAD)simulation.Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron-hole pairs,leading to an increase in the dark signal.

螺牙高度对螺纹桩竖向承载特性的影响

为探明竖向荷载作用下螺牙高度对螺纹桩承载特性及桩周土体的影响,通过室内半面模型桩试验,结合数字图像相关技术(DIC),研究了不同螺牙高度、不同荷载条件对桩身承载性能、桩周土体破坏特征、桩周土体位移场的影响。采用ABAQUS数值模拟方法对模型试验的结果进行验证,并扩展了螺牙高度的取值范围,分析螺纹桩桩身极限承载力与材料利用率、桩周土体应力场分布随螺牙高度变化的规律。结果表明:增加螺牙高度能提升桩身承载力,增大桩周土体位移影响范围,延缓桩侧土体剪切破坏的发展;随着桩身沉降量增加,桩顶荷载以桩侧阻力承受为主,逐渐演变为以桩端阻力承受为主;螺牙高度的增加虽然能提升桩身极限承载力,但桩身材料利用率存在峰值。

The Transplant of Technology of Capacitive Displacement Transducer to Phase Modulation Grating-the Research of the Grating with nm Measuring Resolution

The method rising measuring resolution through reducing pitch of the transducer has brought forward from the basic structure, principle and the corresponding relationship among pitches of capacitive electrodes, period T and phase shift of vv(x,t). But if the traditional technique of PCB made of the transducer is still used, it will meet with difficulties in lead wire. And so the technology transplant from the transducer to grating is presented, the basic principle of the phase modulation grating similar...

以学为中心的现代工程测试技术实验教学探索

“现代工程测试技术”是国内部分高校工科类专业的本科生所必修的一门课程。目前,该课程存在实验对象形式简单、测试方法单一等问题。针对以上问题,开展了以学为中心的实验教学探索。分别设计了一种环形和一种弧形机翼结构模型代替原有的悬臂直梁式机翼结构模型作为实验对象,在原应变测量的基础上增加了使用激光位移传感器和数字图像相关(Digital Image Correlation,DIC)方法进行位移测量、有限元模拟三部分内容。学生对新的机翼结构模型表现出了较大的好奇心,新增的实验方法和有限元模拟也进一步丰富了该课程的教学内容。通过这些探索,可以使学生掌握新的测试方法,调动其课堂积极性和主动性,增强其运用所学理论解决实际问题的能力,显著提升教学效果和质量。

基于数字图像相关方法分析土石混合体的变形行为

为探讨荷载作用下土石混合体的变形行为,通过开展土石混合体的无侧限抗压试验,结合数字图像相关方法(DIC技术)分析不同含石量试样单轴压缩过程中位移、应变(裂缝扩展)演化规律。结果表明:①随着加载的进行,试样水平方向位移较垂直方向更加明显,故变形能力在垂直方向较水平方向更强,抗压性能优于抗剪性能;随着含石量的增大,试样竖向承载能力持续增强;②随着含石量增加,土石比例对试样裂缝损伤发展的抑制作用强于促进作用,导致承载能力随含石量增加而增强;③试样整体在载荷作用下位移变化阶段主要为初始压实、弹性压缩、弹塑性(塑性膨胀)和破坏阶段;在峰值荷载水平下,加载板影响区域发生局部压碎、脱落,直接导致试样出现裂缝扩展行为且压实性能发生断裂失效;④试样在压缩过程中裂缝数量随含石量的增加而逐渐增加,且裂缝分布广泛,裂缝的宽度呈现出逐渐增大的趋势,且应变云图可以更好地表现试样变形、破坏特征;⑤DIC技术应用于土石混合体在抗压试验中变形破坏的研究,不仅能够得到试样破坏过程中观测面的三维全场位移和应变,而且能够直观地反映试样表面裂隙的产生、扩展及相互连通的演化过程,也能够确定裂纹的位置、形态及扩展方向等具体信息。

定射角射孔工艺在大位移定向井中的应用与实践

通过对萨中开发区112#断层区块构造特征和开发井网情况的深入研究,部署距离断层50 m平行断层面钻井的大位移定向井。考虑射孔油层保护要求,结合定射角射孔工艺原理,确定射孔工艺、射孔输送方式及匹配的射孔枪、弹等射孔参数,选用合理的射孔液,采用负压射孔工艺、确定合理负压值,保证了定射角射孔工艺效果。实现了单井日增液17.6 t,日增油4.2 t,年节电约2.56×10^(4) kWh,创造较好的经济效益,保证了油田开发效果。

延长油田东部浅层致密油储层驱油压裂技术及应用

南泥湾采油厂浅层致密油储层采用滑溜水分段压裂取得初步成效,但产量递减快,原因之一就是油藏能量不足。针对浅层致密油藏增能需求,采用大排量、大液量、低砂比的驱油型滑溜水压裂液滞留地层,补充地层能量,通过焖井进行油水置换,形成驱油压裂技术。根据施工排量控制总射孔数,按照每孔排量最少0.3 m^(3)/min进行压裂,压后焖井,通过优化压裂缝模拟设计形成较大的储层改造体积,达到体积压裂的效果。评132井区平2井现场试验结果表明,该工艺实施简单,整个施工泵压较低且平稳,排量稳定,取得了较好的增产效果。

基于Cat.1技术与阵列式位移计的深基坑监测方法与应用

深基坑开挖的危险系数高,容易引发安全事故,需要采用有效的地质灾害监测系统。为实现深基坑施工阶段变形的有效监测与预警,提出了采用基于Cat.1技术与阵列式位移计的无线自动化监测方法。首先通过与传统的LoRa通信技术对比,分析了Cat.1技术的特点和优势。然后把Cat.1技术与阵列式位移计共同应用于基坑监测,建立了监测系统。最后,以某深基坑监测项目为例,分析了代表性测点的水平位移监测结果。结果表明,所建立的监测系统能够稳定地采集监测数据并上传至监测平台,实时反映基坑测点水平位移变化规律,且监测结果的可解释性高,有助于及时发出预警信号,做好风险防范措施。

基于PIV技术的非饱和膨胀土径向劈裂试验研究

非饱和膨胀土的径向劈裂强度与裂隙扩展之间存在密切联系,分析不同含水率下非饱和膨胀土的裂隙演化机制,对南水北调中线工程膨胀土渠段的工程灾害防治具有重要的理论意义和工程实用价值。联合运用WP4C仪、压力板和PIV(Particle image velocimetry,PIV)劈裂试验系统,对南水北调中线工程邓州段某高填方渠堤非饱和膨胀土进行了一系列的持水特性试验和劈裂试验,结合持水特征曲线,揭示了不同含水率膨胀土的劈裂强度、裂隙演化过程、位移矢量场的变化规律及其内在机理。试验表明:(1)膨胀土的含水率和饱和度均随吸力的增大而减小。在低吸力范围内膨胀土试样含水率和饱和度随吸力的增加而减小趋势缓慢;在高吸力范围内,含水率和饱和度与吸力基本呈线性关系,随吸力的增加,试样的含水率和饱和度显著减小。(2)含水率对膨胀土的劈裂强度具有显著影响。随含水率的增加,试样的劈裂峰值荷载呈先增加后减小的变化规律,劈裂峰值荷载在含水率为3%~12%范围内持续增加,而在12%~24%范围内持续减小;上述试验现象与不同含水率膨胀土试样具有不同的颗粒间液桥作用有密切的内在联系。(3)不同含水率下膨胀土劈裂试验荷载-位移曲线均可分为荷载接触阶段、荷载线性增加阶段、张拉破坏阶段和残余阶段。膨胀土劈裂试验不同阶段的裂隙、位移矢量场的变化规律与荷载-位移曲线变化之间存在着一一对应关系。

基于动态驱替扫描技术的特低渗储层微观剩余油赋存状态的研究

为厘清安塞油田长6特低渗油藏微观剩余油赋存特征,明确后续开展三次采油技术方向,基于动态驱替扫描技术监测真实岩心水驱过程微观剩余油赋存特征及动态变化规律。结果表明,基于动态驱替扫描技术及计算机重建技术能够获取不同水驱阶段岩心孔隙内部不同流体的赋存状态信息与实际三维形貌,依据微观剩余油分布形态、位置、赋存量及可动用程度等特征信息,将其分为粒间吸附状、团簇状、喉道状、角隅状、颗粒吸附状及孔表薄膜状剩余油。建立了微观剩余油赋存类型定量判别方法与标准。此外,系统地梳理了不同水驱阶段微观剩余油类型及其变化规律,提出针对性的动用方法与建议,为后续开展化学驱提高油田采收率奠定基础。

微生物协同纳米颗粒驱油的研究进展

随着油田开采的不断深入,传统的驱油方法存在效率低下、环境污染等问题。近年来,微生物技术与纳米技术的结合,为提高油田采收率提供了新的思路。本文综述了微生物与纳米颗粒协同驱油的研究进展,包括微生物纳米驱油技术的研究现状、协同驱油机理、技术的稳定性等,并展望了相关的研究前景。

物联网传感技术在边坡安全自动化监测中的应用

针对传统边坡安全监测方法的弊端,在充分调研边坡安全监测需求的前提下,将北斗卫星导航定位技术、物联网传感技术、云计算技术等进行充分融合,构建高边坡自动化安全监测系统,并利用某公路边坡监测项目对该系统可行性及可靠性进行分析验证。通过对地表位移自动化监测子系统、深部位移自动化监测系统以及降雨量自动化监测子系统监测数据进行分析研究,结合边坡变形特征,将各个自动化监测子系统进行联合,实现边坡安全监测联合预警,提高边坡自动化监测成果及超限预警可靠性。相较于传统人工监测,本文设计开发的边坡自动化安全监测系统可靠性较高,监测成果时效性较强,能够较为准确地对边坡变形趋势进行直观呈现,具有较高的适用性。

The AI Paradox: Mapping the Unintended Disruptions in IT and Beyond

In the realm of Artificial Intelligence (AI), there exists a complex landscape where promises of efficiency and innovation clash with unforeseen disruptions across Information Technology (IT) and broader societal realms. This paper sets out on a journey to explore the intricate paradoxes inherent in AI, focusing on the unintended consequences that ripple through IT and beyond. Through a thorough examination of literature and analysis of related works, this study aims to shed light on the complexities surrounding the AI paradox. It delves into how this paradox appears in various domains, such as algorithmic biases, job displacement, ethical dilemmas, and privacy concerns. By mapping out these unintended disruptions, this research seeks to offer a nuanced understanding of the challenges brought forth by AI-driven transformations. Ultimately, its goal is to pave the way for the responsible development and deployment of AI, fostering a harmonious integration of technological progress with societal values and priorities.

消能减震技术在结构抗震设计中的应用

为探究黏滞阻尼器在建筑工程中的减隔震性能,基于有限元分析软件YJK建立结构模型,并分别对结构进行弹性及弹塑性时程分析。计算结果表明,通过时程分析计算得到的结构底部剪力比值>80%,满足最低结构安全需要。在8度设防地震作用下,设置阻尼器的消能结构层间位移角与原结构x向附加6%阻尼比和y向附加6%阻尼比的位移角基本相同,结构x,y向附加阻尼比平均值分别为6.05%,7.31%。研究表明,黏滞阻尼器有助于提高结构减隔震性能。

GaAs基底上制备圆孔阵列光栅及其影响因素研究

为解决半导体激光器的偏振问题,提出了一种利用泰尔博特位移光刻曝光技术在Ga As衬底上制作周期光栅的方法,并系统研究了工艺参数和抗反射层对制备的周期光栅质量的影响。利用二次光刻工艺和反应离子蚀刻工艺在Ga As衬底上制备圆孔阵列周期光栅;通过电感耦合等离子体蚀刻设备制造均匀光栅。实验结果表明,该工艺流程可制备深度为20~150 nm的动态可调圆孔阵列周期光栅;当曝光剂量为30 m J·cm^(-2),曝光光强度为2 m W·cm^(-2),显影时间为1 min时,所曝光出的周期光栅符合实验要求;重复实验证明了利用泰尔伯特位移光刻技术制备光栅工艺的可行性及稳定性。

“双碳”背景下二氧化碳海洋封存水合物利用技术研究进展

文章聚焦CO_(2)海洋封存进展,重点介绍了CO_(2)水合物海底封存和CO_(2)置换天然气水合物中CH4技术的研究现状。首先,探讨了CO_(2)水合物海洋封存水合物利用技术的基本原理、形成条件,以及海水中无机盐类型浓度以及沉积物层孔隙度对CO_(2)水合物的形成动力学影响;其次,分析了温压条件、海底沉积物以及混合气体对CO_(2)置换天然气水合物影响因素研究;最后,阐述了CO_(2)海洋封存在技术、环保等方面存在的挑战与问题,展望了发展CO_(2)封存技术的迫切性与应用前景。