混合联肢PEC墙结构简化力学分析模型及承载力计算

为克服钢筋混凝土墙肢底部易发生脆性破坏的缺点,提高联肢剪力墙结构的抗震性能,采用PEC剪力墙肢代替混合联肢剪力墙结构中的钢筋混凝土剪力墙肢,形成新型混合联肢PEC墙结构.通过改变钢连梁截面尺寸、PEC墙肢宽厚比以及楼层数形成3个系列共8个模型,研究了弹性耦连比和改变弹性耦连比的方式对混合联肢PEC墙结构滞回性能和应力分布的影响.结果表明:各个系列模型滞回曲线均饱满而稳定,未出现明显捏缩现象,证明混合联肢PEC墙结构抗震性能好、耗能能力强,适用于高烈度抗震设防地区;与已有联肢墙结构研究成果一致,弹性耦连比是影响混合联肢PEC墙结构整体性能的主要因素,并不会因为实现方式不同而影响结构应力分布规律;为保证结构达极限承载能力状态时各层钢连梁均发生剪切屈服并充分发展塑性,同时避免受拉侧墙肢发生延性较差的小偏心受拉破坏,应控制弹性耦连比小于等于70%;基于有限元模型分析结果,探讨了混合联肢PEC墙结构受力机理,建立了结构简化力学分析模型,给出了极限承载力计算公式;试验及有限元模型分析结果与理论计算结果误差在15%以内,且均为理论值偏低,证明本文提出的混合联肢PEC墙结构极限承载力计算公式精度较高且偏于安全,可用于计算结构极限承载力.

Detection of Multi-dimensional Driving Forces of Public Environmental Concern in China:Based on Spatial Heterogeneity Perspectives

Public environmental concern(PEC)is an important bottom-up force in building an environmentally sustainable society.Guided by attitude theory,this paper innovatively constructed a PEC evaluation index system,while introducing entropy weighted-TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)to realize the assessment of PEC.Exploratory spatial data analysis was used to portray the spatio-temporal evolution patterns of PEC in 362 Chinese cities at prefecture-level and above from 2011 to 2018.Furthermore,the Geodetector model was performed to identify the multi-dimensional determinants of PEC from the perspective of spatial heterogeneity.The results indicated that:1)PEC in China exhibited a fluctuating upward trend,consistent with the spatial distribution law of‘Heihe-Tengchong Line’and‘Bole-Taipei Line’;2)the driving effect of each factor varied dynamically,but in general,economic development level,population size,industrial wastewater,and education level were the dominant driving factors explaining the spatial variation of PEC;3)risk detection revealed that four factors,government environmental regulations,PM_(2.5),vegetation coverage,and natural resource endowment,had nonlinear effects on PEC;4)the interactions between factors all demonstrated an enhancement in explaining the spatial differentiation of PEC.PEC was driven by the comprehensive interaction of four-dimensional factors of economy,society,pollutant emissions,and ecology.Among them,population agglomeration accompanied by a high level of regional economy and information technology can explain the increase in PEC to the greatest extent.

T形PEC柱抗震性能的数值模拟分析

利用ABAQUS软件对14个T形PEC柱进行低周反复加载模拟,分析不同参数对T形PEC柱抗震性能的影响规律。结果表明:T形PEC柱的滞回曲线呈饱满的平行四边形,且刚度退化稳定,耗能能力和延性良好;提高混凝土强度等级虽然可增大柱的初始刚度,但混凝土强度等级过高则会导致柱的延性降低,刚度退化加剧,抗震性能降低;在T形PEC柱内设置横向拉杆,且将x方向和z方向的横向拉杆相互焊接,有利于对混凝土形成套箍作用从而提高柱的抗震性能,但拉杆间距不宜大于150 mm;在T形PEC柱的两侧阴角处分别设置1根纵筋并将其与横向拉杆绑定后形成钢筋笼,能够明显的改善柱的抗震性能。

带PEC柱钢板剪力墙结构(弱轴连接)抗震性能有限元分析

为研究边缘柱为部分外包混凝土组合柱的钢板剪力墙结构(弱轴连接)的抗震性能,使用有限元软件ABAQUS完成1榀边缘柱为H型钢柱、5榀边缘柱为PEC柱的钢板剪力墙结构(弱轴连接)在循环荷载作用下的有限元数值模拟,得到结构的应力分布、破坏模式、滞回曲线、耗能性能、骨架曲线以及刚度退化曲线,并完成了1榀带PEC柱的钢板剪力墙结构(弱轴连接)的试验,验证了有限元模拟的正确性.分析表明在钢板剪力墙结构中(弱轴连接),将PEC柱作为剪力墙的边缘框架柱,同样可以很好的约束屈曲后的钢板剪力墙,使其充分发挥屈曲后的性能,显著提升整体结构的抗侧刚度、承载力以及耗能性能.

PEC柱-钢梁摩擦耗能部分自复位组合框架抗震试验研究

为系统研究梁柱采用自复位连接组合框架的抗震机理,选取预拉杆长度设置、PEC柱截面强弱轴布置和柱脚连接方式3个设计参数,设计制作了4榀PEC柱-钢梁梁柱摩擦耗能部分自复位连接组合框架1∶2缩尺试件并进行拟静力抗震试验。通过试验现象观察和数据分析,对试件的滞回特性、抗侧刚度退化、复位能力、滞回耗能等抗震性能进行研究。结果表明:摩擦耗能部分自复位连接通过T形件长圆孔合理设置实现了“设计地震水平阶段实现复位,大震设计水平阶段自复位连接连接转化为伴随出现螺栓承压型受力实现部分自复位”的性能化设计目标;设计地震阶段,试件主要通过辅助摩擦耗能件耗能,且卸载残余侧移小于自复位结构侧移限值(0.3%),在大震作用阶段,试件通过辅助摩擦耗能件与结构构件损伤联合耗能,承载能力仍继续增大,且仍具有部分自复位能力;预拉杆设置有限长度可显著增强结构整体性,PEC柱弱轴布置一定程度上降低了结构整体性,而PEC柱脚采用铰接可显著削弱结构整体性。

NhaA通过维持细菌包膜的完整性和逃避补体攻击增强ExPEC的毒力

肠外致病性大肠杆菌(ExPEC)是一种在肠外组织中定植的细菌,主要包括禽致病性大肠杆菌(APEC)、致新生儿脑膜炎大肠杆菌(NMEC)和尿道致病性大肠杆菌(UPEC)。由于其高致病性、高致死率和潜在的人兽共患性,ExPEC导致人类和动物多种宿主严重感染,每年给养殖业造成巨大的经济损失,同时对人类健康造成严重威胁。然而,目前尚无能够全面防控ExPEC感染的有效疫苗。因此,深入研究ExPEC影响其毒力的关键因子和相关机制,将为未来开发有效疫苗提供重要的科学参考。

MXene-based hybrid materials for electrochemical and photoelectrochemical H_(2) generation

The conversion of solar energy to produce clean hydrogen fuel through water splitting is an emerging strategy for efficiently storing solar energy in the form of solar fuel.This aligns with the increasing global demand for the development of an ideal energy alternative to fossil fuels that does not emit greenhouse gases.Electrochemical(EC) and photoelectrochemical(PEC) water splitting technologies have garnered significant attention worldwide for advanced hydrogen solar fuel production in recent decades.To achieve sustainable green H_(2) production,it is essential to create efficient catalyst materials that are low-cost and can replace expensive noble metal-based catalysts.These characteristics make them an ideal catalyst material for the process.Two-dimensional MXenes with M_(n+1)X_(n) structure have been identified as a promising option for EC and PEC water splitting due to their superior hydrophilicity,metal-like conductivity,large surface area,and adjustable surface chemistry.Here,we present a summary of recent advancements in the synthesis and performance enhancement methods for MXene hybrid materials in hydrogen production through EC and PEC water splitting.Furthermore,we examine the challenges and insights associated with the rational design of MXene-based hybrid materials to facilitate efficient water splitting for sustainable solar fuel production.

CO_(2) conversion to solar fuels and chemicals:Opening the new paths

This future article discusses the new prospects and directions of CO_(2)conversion via the photo-electrocatalytic(PEC)route.The second(2nd)generation solar fuels and chemicals(SFs)are generated directly in PEC systems via electrons/protons reactions without forming molecular H_(2)as an intermediate,overcoming the thermodynamics limitations and practical issues encountered for electro-fuels produced by multistep thermocatalytic processes(i.e.CO_(2)conversion with H_(2)coming from water electrolysis).A distributed and decentralized production of SFs requires very compact,highly integrated,and intensified technologies.Among the existing reactors of advanced design(based on artificial leaves or photosynthesis),the integrated photovoltaic plus electrocatalytic(PV-EC)device is the only system(demonstrated at large scale)to produce SFs with high solar-to-fuel(STF)efficiency.However,while the literature indicates STF efficiency as the main(and only)measure of process performance,we remark here the need to refer to productivity(in terms of current density)and make tests with reliable flow PEC systems(with electrodes of at least 5–10 cm^(2))to accelerate the scaling-up process.Using approaches that minimize downstream separation costs is also mandatory.Many limitations exist in PEC systems,but most can be overcome by proper electrode and cell engineering,thus going beyond the properties of the electrocatalysts.As examples of current developments,we present the progress of(i)artificial leaf/tree devices for green H_(2)distributed production and(ii)a PEC device producing the same chemicals at both cathode and anode parts without downstream operations for green solvent distributed production.Based on these developments,future directions,such as producing fertilizers and food components from the air,are outlined.The aim is to provide new ideas and research directions from a personal perspective.

孤独症儿童PECS行为训练图卡插图风格设计研究

目的:近年来的研究数据显示,中国孤独症儿童的患病率持续上升,引起了学术界的关注。如何有效地对孤独症儿童进行干预和治疗,已成为当前亟待解决的问题。社会各界纷纷呼吁重视与关怀孤独症群体,建立更加科学、人性化和本土化的干预辅助体系。文章探讨符合我国孤独症儿童认知特点的PECS(Picture Exchange Communication System,图片交流沟通系统)行为训练图卡插图的设计表现风格,以增强图卡的有效性和吸引力。方法:通过系统的文献研究、线上调研以及专业意见收集,深入研究儿童插图的发展现状,并结合孤独症儿童的视觉偏好,总结出符合我国孤独症儿童PECS行为训练图卡插图的设计表现风格。结论:研究结果表明,扁平化、简洁具象化的插图风格更符合我国孤独症儿童的审美偏好,清晰的图形及具象化的表达方式能降低认知负担,使图像更易于理解,有助于提供稳定且可预测的视觉信息,符合孤独症儿童对简单直观视觉元素的偏好,能够显著提高孤独症儿童的学习兴趣和参与度,从而增强孤独症儿童的行为能力和沟通表达能力。设计应遵循独特的创意表达、简化和重复、注重细节等原则,从而使孤独症儿童PECS行为训练图卡满足孤独症儿童的学习、表达和发展需求。

试论PECS在孤独症学生生活语文课堂中的应用策略

图片交换沟通系统(The Picture Exchange Communication System,PECS)是目前广泛应用于孤独症儿童康复训练的一种训练方法。PECS以图片为载体,运用图片之间的内在联系和差异,由浅入深、循序渐进地对孤独症儿童进行干预。其按照六个阶段进行规范训练,通过对孤独症儿童进行单次时间短、频次密的外界刺激,使他们有效感知外部刺激,减弱对固定目标的负强化,改进语言缺失,改善交际障碍。针对低年级生活语文课堂教学,运用图片交换沟通系统理论展开探析。

基于PEC技术的水电站照明电源设计研究

本研究针对水电站的照明用电需求,设计了一套基于光电化学电池(Photoelectrochemical Cell,PEC)技术的自主照明电源系统。该系统采用高效率的单晶硅光伏组件作为光电转换设备,结合镍氢电池构建储能单元,并通过最大功率点跟踪(Maximum Power Point Tracking,MPPT)技术和智能化控制策略,实现了对水电站照明负荷的稳定供电。实验结果表明,系统在连续运行15 d的测试中,光伏发电量、储能容量以及负荷供电均达到预期目标,证明了系统的高效性、稳定性以及可靠性。此外,系统的模块化设计和智能控制策略提高了系统的灵活性与可维护性,为水电站提供了一种环保、高效且经济的照明解决方案。

SPB联合Pecs Ⅱ阻滞对全麻乳腺癌根治患者麻醉苏醒、镇痛水平及不良反应的影响

目的 探究全麻乳腺癌根治患者给予前锯肌平面阻滞(SPB)联合Ⅱ型胸神经(Pecs Ⅱ)阻滞对机体疼痛、不良反应、麻醉苏醒的影响。方法 选取商丘市第一人民医院2019年4月至2021年1月就诊的120例全麻乳腺癌根治患者为研究对象。根据随机数据分组方法分为对照组(Pecs Ⅱ阻滞)与观察组(SPB联合Pecs Ⅱ阻滞),各60例,采用视觉模拟评分量表(VAS)评估两组疼痛程度;分析两组麻醉苏醒时间、自主呼吸时间、意识恢复时间、拔管时间;对比两组免疫功能指标和氧化应激分子;对比两组不良反应发生率;采用Ramsay镇静评分评估镇静程度。结果 观察组3 h、12 h、24 h、48 h VAS评分低于对照组,差异有统计学意义(P<0.05);术后,两组组麻醉苏醒时间对比,观察组患者相对于对照组患者更快恢复意识、意识恢复时间与拔管时间缩短,差异有统计学意义(P<0.05);术后,观察组与对照组免疫功能指标均低于术前,且观察组免疫功能指标高于对照组,差异有统计学意义(P<0.05);术后,两组氧化应激分子比较,观察组超氧化物歧化酶(SOD)指标明显高于对照组,观察组烟酰胺腺嘌呤二核苷酸磷酸氧化酶4(NOX4)、髓过氧化物酶(MPO)、丙二醇(MDA)指标低于对照组,差异有统计学意义(P<0.05);两组不良反应发生率对比,差异无统计学意义(P> 0.05);观察组术后1 h、12 h、24 h、48 h Ramsay评分较对照组低,差异有统计学意义(P<0.05)。结论 SPB联合Pecs Ⅱ麻醉,患者疼痛程度显著减轻,氧化应激水平明显改善,患者可更好苏醒,增强免疫力,以此加快机体恢复,临床应用效果显著。

窄翼缘PEC中长柱轴压整体稳定性能试验研究

为研究窄翼缘PEC中长柱轴压整体稳定性能,设计制作9根组合长细比介于76~141(正则化长细比介于0.84~1.55)的窄翼缘PEC中长柱,进行轴压整体稳定性能试验。研究窄翼缘PEC中长柱的初始弯曲、长细比、混凝土强度等因素对其破坏模式和轴压整体稳定承载力的影响。试验结果表明,窄翼缘PEC中长柱在轴压荷载下的破坏模式表现为绕弱轴的弯曲失稳,长细比和初始弯曲显著影响试件的破坏模式和极限承载力。当试件的正则化长细比大于1.0,初始弯曲大于L/1000时,试件的破坏模式表现为整体极值点失稳;当试件的正则化长细比大于1.0,初始弯曲小于L/2000时,试件的破坏模式表现为弹性平衡分岔失稳;当试件的正则化长细比小于1.0,初始弯曲小于L/2000时,试件的破坏模式介于弹塑性极值点失稳和平衡点分岔失稳之间;初始弯曲一致时,试件的极限承载力随着长细比的增大迅速降低。采用ABAQUS有限元软件建立窄翼缘PEC中长柱有限元模型,将计算承载力与现行规范计算结果进行对比。结果表明,试件轴压整体稳定承载力比规范承载力高出20%,按现行规范计算整体稳定承载力时,没有充分考虑混凝土和型钢的协同作用,规范计算结果偏保守。

AC800PEC控制器与ACS800多传动系统通讯

结合江苏沙钢集团有限公司热连轧运输辊道自动化控制系统,通过对自动化网络硬件配置、参数设定、软件编程,实现ABB控制器与ACS800多传动之间正常通讯,使得钢卷运输辊道控制系统能够稳定、快速、准确地满足现场生产控制要求。

Adenosine or Magnesium Sulphate as Adjuvants for Pectoral Nerves Block in Modified Radical Mastectomy: A Randomized Controlled Trial

Introduction: Magnesium sulphate can prolong the effect of local anaesthetics. Adenosine has not been compared to other local anaesthetics adjuvants. In the present study we aimed to compare the effect of adding magnesium sulphate and adenosine to bupivacaine for pectoral nerves block. Patients and Methods: In this randomized controlled trial, 90 females scheduled for breast surgery were included. Patients were divided into three groups. Patients received general anaesthesia with pectoral nerves block. Group C, A, and M had bupivacaine only, bupivacaine + adenosine, and bupivaciane + magnesium sulphate respectively. Post-operative visual analogue score, block duration, post-operative morphine consumption, sedation score, and peri-operative haemodynamic changes were recorded. Results: Visual analog score was lower in Group M compared to other groups. Group A and M showed significant longer duration of the block. Group M showed significant longer duration of action than Group A (p = 0.034). The total peri-operative morphine used was higher in Group C (p 0.05). Conclusions: Local anaesthetic adjuvants such as adenosine or magnesium sulphate can improve pectoral nerves block characteristics. Magnesium sulphate has an advantage over adenosine by increasing the block duration.

Gradient Si-and Ti-doped Fe_(2)O_(3) hierarchical homojunction photoanode for efficient solar water splitting:Effect of facile microwave-assisted growth of Si-FeOOH on Ti-FeOOH nanocorals

The construction of a homojunction is an effective approach for addressing issues such as slow charge separation and charge-transfer kinetics in photoanodes.In the present work,we designed a gradient Si-and Ti-doped Fe_(2)O_(3) homojunction photoanode to improve the photoelectrochemical(PEC)performance of a Ti-doped Fe_(2)O_(3) photoanode.Ti-FeOOH nanocorals were synthesized using a hydrothermal process,and Si-FeOOH was grown on Ti-FeOOH nanocorals using a rapid and facile microwaveassisted(MW)technique.By varying the MW irradiation time,the thickness of the Si/Ti:Fe_(2)O_(3) photoanode was adjusted and an optimized 3-Si/Ti:Fe_(2)O_(3) photoelectrode was achieved with a significantly enhanced photocurrent density(1.37 mA cm^(-2) at 1.23 V vs.RHE)and a cathodic shift of the onset potential(150 mV)compared with that of bare Ti-Fe_(2)O_(3).This enhanced PEC performance can be ascribed to homojunction formation and Si gradient doping.The Si dopant increased the donor concentration and the formation of a homojunction improved the intrinsic built-in electric field,thereby promoting charge separation and charge transfer.Furthermore,the as-formed homojunction passivated the surfacetrapping states,consequently improving the charge transfer efficiency(60%at 1.23 VRHE)at the photoanode/electrolyte interface.These findings could pave the way for the microwave-assisted fabrication of diverse efficient homojunction photoanodes for PEC water splitting applications.

带PEC柱的钢框架结构Pushover分析

对于多高层建筑而言,部分外包混凝土柱(PEC柱)是非常理想的边缘约束构件。为探究带PEC柱钢框架结构的力学性能,采用OpenSees有限元软件建立8层及12层共12个带PEC柱钢框架结构模型算例并进行Pushover分析。通过软件模拟分析,得到PEC柱内填混凝土等级和型钢板件的厚度变化对整体结构力学性能各个指标的影响。分析表明,在型钢钢柱中灌入混凝土提高了结构的抗侧刚度、延性及承载能力,PEC柱相关参数的变化对结构底部的影响程度大于结构顶部。

内插螺旋肋的AlCl_(3)反应余热回收管传热与阻力特性研究

针对三氯化铝反应炉余热回收装置传热效率低的问题,采取在余热回收管内插入螺旋肋的强化传热技术。利用数值模拟方法,探究改变螺旋肋结构参数对余热回收管内流体传热性能与流动阻力特性的影响。研究结果表明:改变螺旋头数c、螺旋导程s、肋高宽比b/a对管内努塞尔数Nu和阻力系数f均有不同程度的影响。综合传热性能使用综合评价因子PEC进行评价,较高雷诺数下增加螺旋头数c或减小导程s使综合传热性能下降;在给定雷诺数范围内适当提升高宽比b/a可有效提高综合传热性能。

Analysis of the factors controlling performances of Au-modified TiO2 nanotube array based photoanode in photo-electrocatalytic(PECa)cells

The efficiency of photo-electrocatalytic（PECa） devices for the production of solar fuels depends on several limiting factors such as light harvesting, charge recombination and mass transport diffusion. We analyse here how they influence the performances in PECa cells having a photo-anode based on Au-modified TiOnanotube（TNT） arrays, with the aim of developing design criteria to optimize the photo-anode and the PECa cell configuration for water photo-electrolysis（splitting） and ethanol photo-reforming processes.The TNT samples were prepared by controlled anodic oxidation of Ti foils and then decorated with gold nanoparticles using different techniques to enhance the visible light response through heterojunction and plasmonic effects. The activity tests were made in a gas-phase reactor, as well as in a PECa cell without applied bias. Results were analysed in terms of photo-generated current, Hproduction rate and photoconversion efficiency. Particularly, a solar-to-hydrogen efficiency of 0.83% and a Faradaic efficiency of 91%were obtained without adding sacrificial reagents.

SINOPEC's Independent MTO Technology in the Phase of Commercialization

On October 10, 2011 the 600 kt/a methanol-to-olefin(MTO) unit at the Zhongyuan Petrochemical Companywhich adopts the SINOPEC’s independent technology, habeen cranking out the qualified polymerization-grade ethylene and propylene products to achieve successful startupat the first attempt while meeting the goals on safety