Achieving a superior Na storage performance of Fe-based Prussian blue cathode by coating perylene tetracarboxylic dianhydride amine

Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crystalline water and vacancies of Fe-PB lattice,the low electrical conductivity,and the dissolution of metal ions lead to limited capacity and poor cycling stability.In this work,a perylene tetracarboxylic dianhydride amine(PTCDA)coating layer is successfully fabricated on the surface of Fe-PB by a liquid-phase method.The aminated PTCDA(PTCA)coating not only increases the specific surface area and electronic conductivity but also effectively reduces the crystalline water and vacancies,which avoids the erosion of Fe-PB by electrolyte.Consequently,the PTCA layer reduces the charge transfer resistance,enhances the Na-ion diffusion coefficient,and improves the structure stability.The PTCA-coated Fe-PB exhibits superior Na storage performance with a first discharge capacity of 145.2 mAh g^(−1) at 100 mA g^(−1).Long cycling tests exhibit minimal capacity decay of 0.027%per cycle over 1000 cycles at 1 A g^(−1).Therefore,this PTCA coating strategy has shown promising competence in enhancing the electrochemical performance of Fe-PB,which can potentially serve as a universal electrode coating strategy for Na-ion batteries.

Topology optimization and seismic collapse assessment of shape memory alloy(SMA)-braced frames:Effectiveness of Fe-based SMAs

This paper presents a seismic topology optimization study of steel braced frames with shape memory alloy(SMA)braces.Optimal SMA-braced frames(SMA-BFs)with either Fe-based SMA or NiTi braces are determined in a performance-based seismic design context.The topology optimization is performed on 5-and 10-story SMA-BFs considering the placement,length,and cross-sectional area of SMA bracing members.Geometric,strength,and performance-based design constraints are considered in the optimization.The seismic response and collapse safety of topologically optimal SMA-BFs are assessed according to the FEMA P695 methodology.A comparative study on the optimal SMA-BFs is also presented in terms of total relative cost,collapse capacity,and peak and residual story drift.The results demonstrate that Fe-based SMA-BFs exhibit higher collapse capacity and more uniform distribution of lateral displacement over the frame height while being more cost-effective than NiTi braced frames.In addition to a lower unit price compared to NiTi,Fe-based SMAs reduce SMA material usage.In frames with Fe-based SMA braces,the SMA usage is reduced by up to 80%.The results highlight the need for using SMAs with larger recoverable strains.

SMA碟簧群的循环受压性能及简化模型

该研究提出将多个形状记忆合金(SMA)碟簧片并联排列形成碟簧组,然后在碟簧组间加入垫片分隔、串联排列形成碟簧群,以提供更高的承载力及变形能力。采用有限元软件ABAQUS建立了一系列SMA碟簧群的三维精细化有限元模型,并进行非线性循环受压分析。结果表明:与钢碟簧的“三角形”荷载-位移曲线相比,SMA碟簧群的荷载-位移曲线呈现鲜明的“旗帜形”特性,具有明显的正向及反向转变平台。随着碟簧片数的增加,碟簧组的总可恢复变形量基本不变,极限承载力及割线刚度近似成比例增加,而随着碟簧组数的增加,碟簧群的总可恢复变形量增加,极限承载力不变,割线刚度近似成比例降低。因此,可根据碟簧群总极限承载力及变形能力的需要,灵活调整碟簧片及碟簧组的数量及布置方式。碟簧组的各层碟簧片由于边界条件不同,应力分布存在明显差异,而变形量亦呈现两端大中间小的哑铃形分布模式,其中加载端碟簧片变形量最大,若超过极限变形量可能发生翻转失效,值得注意。提出了SMA碟簧群的简化模型,通过简化及精细模型的非线性循环受压分析,发现该简化模型的循环受压荷载-位移曲线与精细模型吻合良好,而计算效率提高约38倍。将SMA碟簧群应用于自复位NZ梁柱节点中,并对自复位钢框架进行了验证性的滞回分析。结果表明:采用SMA碟簧群的自复位钢框架最大侧移为4%时可完全复位,且二次刚度相比采用预应力钢绞线的传统自复位钢框架提高近100%,极限承载力提高70%。

高速公路改性沥青SMA上面层施工技术及应用效果

为研究高速公路改性沥青SMA上面层施工技术,提高沥青路面行车的舒适性和安全性,依托实际工程,介绍了改性沥青SMA上面层原材料的各项指标要求,研究了改性沥青SMA上面层的施工技术要点,并进行严格的施工质量检测。

SMA限位对铁路自复位桥墩地震反应的影响

为研究形状记忆合金(SMA)对铁路自复位桥墩地震反应的影响,在已验证的两弹簧模型上增加SMA限位单元,以某铁路桥墩为工程背景,基于OpenSees平台建立数值分析模型,通过输入3条强震记录,采用非线性时程分析方法进行SMA限位的桥墩影响分析。讨论SMA限位装置关键参数初始间隙、初始预加力变化对墩顶位移和墩底弯矩的影响规律,并与预应力钢筋限位进行比较。研究结果表明:在普通地震动El-Centro与Taft波下,自复位桥墩的墩顶位移随限位装置初始间隙δ减小而减小,墩底弯矩随初始间隙δ减小而增大;随SMA限位装置初始预加力增大,自复位桥墩的墩顶位移减小,墩底弯矩增大。在近断层地震动Northridge下,SMA限位对自复位桥墩地震反应的影响复杂。在3条强震记录下,与预应力筋限位相比,SMA限位会减小墩底弯矩,增大墩顶水平位移。

SMA绞线预制梁-柱自复位耗能节点数值研究与参数优化

为了提高预制混凝土框架的抗震能力并控制震后残余变形,提出了一种新型的混合自复位预制混凝土梁柱节点(self-centring precast concrete beam-column connection,SC-PCBCC),其中采用了旋转摩擦阻尼器(rotational friction hinge damper,RFHD)和形状记忆合金(shape memory alloy,SMA)并联的结构。重点探讨了使用SMA绞线控制的自复位装置对SC-PCBCC进行改进。首先,介绍了SC-PCBCC的结构和工作原理;其次验证对比了1.0%、1.5%、2%和2.0%预应变下的超弹性1×7 SMA绞线、RFHD和SC-PCBCC的有限元模型,并进行了初步验证。研究结果表明,该节点具有较高的刚度、承载力、耗能能力以及较好的复位性能;最后对SC-PCBCC中SMA绞线的关键参数:SMA绞线预应变、直径和长度进行了参数分析,以优化其抗震性能。建议SC-PCBCC使用的SMA绞线初始预应变、直径和长度范围分别为1.5%~2.0%、15~18 mm和175~205 mm,以实现SC-PCBCC的优异承载性能、能量耗散和自复位性能。此外,节点中的SMA绞线和RFHD可在震后快速更换,实现高效灾后修复。总体而言,所提出的SC-PCBCC表现出了卓越的减震能力、自复位能力和可修复性。

沥青玛蹄脂碎石混合料(SMA-10)配合比设计

沥青玛蹄脂碎石混合料因其良好的耐久性、抗疲劳性和高温稳定性,在高等级公路工程中得到了广泛的应用,但其设计繁琐,为更好地发挥骨架密实型结构,本文在三多一少级配设计特点下,添加纤维以提高骨架加筋效果,结果表明:通过对沥青玛蹄脂混合料SMA-10配合比设计的三个阶段,SMA-10沥青混合料最佳沥青用量为6.1%,木质素纤维(沥青混合料质量%)0.3%时,以实际工程为依据,所制备的SMA-10混合料高温稳定性达4 195次/mm、水稳定度在85%以上,冻融劈裂强度大于80%均符合规范,能够满足道路工程的要求。达到了优化配合比的目的,对提高沥青路面的使用性能和使用寿命具有实际意义。

Clean production of Fe-based amorphous soft magnetic alloys via smelting reduction of high-phosphorus iron ore and apatite

Separated preparation of prealloys and amorphous alloys results in severe solidification-remelting and beneficial element removal-readdition contradictions,which markedly increase energy consumption and emissions.This study offered a novel strategy for the direct production of FePC amorphous soft magnetic alloys via smelting reduction of high-phosphorus iron ore(HPIO)and apatite.First,the thermodynamic conditions and equilibrium states of the carbothermal reduction reactions in HPIO were calculated,and the element content in reduced alloys was theoretically determined.The phase and structural evolutions,as well as element migration and enrichment behaviors during the smelting reduction of HPIO and Ca_(3)(PO_(4))_(2),were then experimentally verified.The addition of Ca_(3)(PO_(4))_(2)in HPIO contributes to the enrichment of the P element in reduced alloys and the subsequent development of Fe_(3)P and Fe_(2)P phases.The content of P and C elements in the range of 1.52 wt% -14.63 wt% and 0.62 wt% -2.47 wt%,respectively,can be well tailored by adding 0-50 g Ca_(3)(PO_(4))_(2)and controlling the C/O mole ratio of 0.8-1.1,which is highly consistent with the calculated results.These FePC alloys were then successfully formed into amorphous ribbons and rods.The energy consumption of the proposed strategy was estimated to be 2.00×10^(8) kJ/t,which is reduced by 30% when compared with the conventional production process.These results are critical for the comprehensive utilization of mineral resources and pave the way for the clean production of Fe-based amorphous soft magnetic alloys.

Wear Properties of Plasma Transferred Arc Fe-based Coatings Reinforced by Spherical WC Particles

Fe-based coatings reinforced by spherical WC particles were produced on the 304 stainless steel by plasma transferred arc(PTA) to enhance the surface wear properties. Three different Fe/WC composite powder mixtures containing 0 wt%, 30 wt%, and 60 wt% of WC were investigated. The microstructure and phase composition of the Fe/WC composite PTA coatings were evaluated systemically by using scanning electron microscope(SEM) and X-ray diffraction(XRD). The wear properties of the three fabricated PTA coatings were investigated on a BRUKER UMT TriboLab. The morphologies of the worn tracks and wear debris were characterized by using SEM and 3 D non-contract profiler. The experimental results reveal that the microhardness on the cross-section and the wear resistance of the fabricated coatings increase dramatically with the increasing adding WC contents. The coating containing 60 wt% of WC possesses excellent wear resistance validated by the lower coefficients of friction(COF), narrower and shallower wear tracks and smaller wear rate. In the pure Fe-based coating, the main wear mechanism is the combination of adhesion and oxidative wear. Adhesive and two-body abrasive wear are predominated in the coating containing 30 wt% of WC, whereas threebody abrasion wear mechanism is predominated in the coating containing 60 wt% of WC.

FORMATION OF GRADIENT COATING OF Fe-BASED ALLOY WITH RARE EARTHS BY PLASMA SURFACING

A gradient coating of Fe-based alloy was manufactured with rare earths (RE) by plasma surfacing on Q235 steel substrate. The coatings were studied by using X-ray diffraction(XRD), scanning electron microscope(SEM), differential thermal analyzer(DTA), and electron probe micro-analyzer (EPMA). The results show that the phases of the two kinds of coatings(with and without RE) both include α-Fe, Fe7C3, Fe3C, Cr2B, Fe2B and FeB. The microstructure of F314 coating is mainly hypereutectic, the pro-phases Cr7C3 and Cr2B are loose, crassi, spiculate and contain microcracks. The brittleness of the coating is high, and the average hardness is 787 HV. When 0.8wt% RE was added into the F314 alloy, the microstructure varied from hypoeutectic to hypereutectic continuously, The hardness appears as gradient distribution with the highest value of 773 HV, meanwhile, the brittleness decreases significantly. The formation of gradient structure depends on the fallowing factors: (i) the conversion of RE. The addition of RE lowers the elements point and Fe-C eutectic temperature, thus the base metal melting acutely. (ii) the heating of plasma arc. Graded temperature results in directional solidification, thus the gradient structure forms easily. The main reasons for the hardness decrease with RE addition in the alloy are the ratio of hard phase lowering and the hardness of the hard phase decreasing.

建筑SMA/橡胶复合型隔震支座老化性能的研究

研究建筑形状记忆合金(SMA)/橡胶复合型隔震橡胶支座的老化性能。结果表明:丁腈橡胶(NBR)/溴化丁基橡胶(BIIR)并用比为45/55的并用胶的耐热老化性能最佳;采用最佳并用比的NBR/BIIR并用胶的建筑SMA/橡胶复合型隔震支座热老化后的滞回曲线变化较小,即其水平力学性能稳定,而紫外线照射和温度对其性能有影响,但影响有限,可以通过增加遮蔽物来降低紫外线照射和温度的影响,以延长使用寿命。

Corrosion Behavior of Plasma Transferred Arc Fe-based Coating Reinforced by Spherical Tungsten Carbide in Hydrochloric Acid Solutions

Fe-based coatings reinforced by spherical tungsten carbide were deposited on 304 stainless steel using plasma transferred arc(PTA) technology.The composition and phase microstructure of the coatings were evaluated using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS) and X-ray diffraction(XRD).The corrosion behaviors of the coatings in 0.5 mol/L HCl solution were studied using polarization curve and electrochemical impedance spectroscopy(EIS) measurements.The experimental results shows that the tungsten carbide improves the corrosion resistance of the Fe-based alloy coating,but increase in the mass fraction of tungsten carbide leads to increasing amount of defects of holes and cracks,which results in an adverse effect on the corrosion resistance.The defects are mainly present on the tungsten carbide but also extend to the Fe-based matrix.The tungsten carbide,acting as a cathode,and binding material of Fe-based alloy,acting as an anode,create a galvanic corrosion cell.The binding material is preferentially corroded and causes the degradation of the coating.

超声冲击对SMA490BW耐候钢焊接接头腐蚀疲劳的影响

采用USP-300超声表面加工装置对SMA490BW耐候钢表面进行超声冲击处理。研究超声冲击前后试件的显微组织、显微硬度和残余应力,比较超声冲击前后SMA490BW耐候钢焊接接头的腐蚀速率和腐蚀疲劳寿命。通过光学显微镜观察超声冲击后SMA490BW耐候钢的显微组织,采用测试仪器测试焊接接头的表面硬度和残余应力,分析超声冲击提高SMA490BW耐候钢抗腐蚀性及其疲劳寿命的机理。结果表明,超声冲击处理能使材料表层晶粒细化形成致密的塑性变形层,提高显微硬度,并在材料表面引入有效的残余压应力,降低腐蚀速率,减小失重量。同时,超声冲击处理后裂纹扩展路径变得更加复杂,裂纹扩展速率降低,焊接接头腐蚀疲劳寿命得到提高。

Urantide对ApoE^(-/-)小鼠动脉粥样硬化合并代谢相关脂肪性肝病中α-SMA、OPN的影响

目的观察Urantide对ApoE^(-/-)小鼠代谢相关脂肪性肝病(MAFLD)中α-SMA、OPN的影响,探讨其在动脉粥样硬化(AS)合并MAFLD中对肝纤维化的治疗作用。方法将ApoE^(-/-)小鼠分为AS模型组、辛伐他汀组、Urantide低、中、高剂量组,C57BL/6为对照组;对照组和AS模型组给予生理盐水20 mg/kg、辛伐他汀组给予辛伐他汀5 mg/kg、Urantide组分别给予Urantide 20 mg/kg、30 mg/kg、40 mg/kg,治疗14d后,HE及油红O染色观察肝脏病理改变;Masson三色染色观察肝脏胶原纤维表达;免疫组化法检测肝脏α-SMA表达及定位;RT-qPCR检测UⅡ/UT系统基因变化;Western blotting检测肝内α-SMA、OPN、UⅡ/UT系统的表达。结果与对照组相比,AS模型组小鼠肝脏出现脂肪变性,油红O染色出现大量脂滴浸润,窦周间隙出现胶原纤维沉积,肝脏α-SMA、OPN、UII、GPR14蛋白表达升高;UII、GPR14 mRNA水平升高;经Urantide治疗后,肝脏脂滴减少、脂肪性病变显著改善,胶原纤维减少,UⅡ/UT系统和α-SMA、OPN表达显著降低。结论Urantide可能通过拮抗UⅡ/UT系统从而改善ApoE^(-/-)小鼠肝脏脂肪变性,达到治疗肝纤维化的作用。

短期风电功率CEEMDAN-SMA-LSSVM预测模型研究

为了提高风力发电功率预测的准确性,建立了基于CEEMDAN分解的SMA算法优化LSSVM的短期风电功率组合预测模型。首先,采用完全集合经验模态分解(CEEMDAN)对原始风电功率数据进行分解与重构。随后,为了进一步优化最小二乘向量支持机模型(LSSVM)的参数,引入了黏菌算法(SMA)优化,通过调整惩罚参数和核参数来提高模型性能,最后,构建多种对比模型对比分析表明CEEMDAN-SMA-LSSVM模型预测精度最高,预测结果更接近真实值。研究可用于风电场短期风电功率预测使用。

下睑成形术联合PDS线提拉SMAS层对中面部年轻化的疗效观察

目的观察下睑成形术联合PDS线提拉浅表肌腱膜系统(SMAS)层对中面部年轻化的疗效。方法选择面部松弛50例患者,根据不同手术方式分为下睑术组(单纯应用下睑成形术)14例、PDS组(单纯应用PDS线提拉除皱术)10例、联合组(应用下睑成形术联合PDS线提拉除皱术)26例。采用5分制方法评价各组患者术后满意程度,采用面颊部皮肤松弛及鼻唇沟的深浅改善情况量表评估面部松弛改善程度,采用中下面部衰老评分量表评价面部衰老改善程度。比较各组手术的安全性及并发症发生情况。结果术后12、18个月,联合组满意率及面部松弛改善率均高于下睑术组和PDS组(P<0.05),而下睑术组与PDS组差异无显著性(P>0.05);各组患者面部衰老评分较术前降低(P<0.05),且联合组低于下睑术组和PDS组(P<0.05)。各组手术安全性均较高,且联合组并发症总发生率均低于下睑术组和PDS组,但组间差异无统计学意义(P>0.05)。结论下睑成形术联合PDS线提拉SMAS层除皱术在中面部年轻化治疗中效果确切,面部皮肤松弛明显改善,手术安全性高,术后恢复快,并发症少。

轻度解交联橡胶粉干法改性SMA13性能研究

通过沥青混合料车辙试验、小梁弯曲试验、冻融劈裂及浸水马歇尔试验,研究了不同掺量轻度解交联橡胶粉(LDCR)对干法改性SMA13高温性能、低温性能与水稳定性的影响。结果表明,掺入LDCR提高了SMA13的高温性能,尤其当掺量≥2%时,混合料的动稳定度超过4.5%SBS改性SMA13(对照组);2%掺量的LDCR干法改性SMA13低温抗裂性最优;总体上LDCR干法改性SMA13的水稳定性低于对照组。综合考虑,LDCR的最佳掺量为2%,与对照组相比,可降低材料成本约5%。

萆薢分清颗粒对单侧输尿管梗阻肾纤维化大鼠mTOR、α-SMA、Col-Ⅰ蛋白表达影响研究

目的 观察萆薢分清颗粒对单侧输尿管梗阻大鼠肾纤维化相关蛋白雷帕霉素靶蛋白(mTOR)、α-平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原(Col-Ⅰ)的影响,探讨萆薢分清颗粒的肾脏保护作用。方法 取60只SPF级雄性SD大鼠,从中随机取10只作为空白组,其余50只大鼠采用单侧输尿管梗阻术构建肾纤维化模型。将造模成功大鼠随机分为模型组、氯沙坦组及萆薢分清高、中、低剂量组,每组10只,萆薢分清高、中、低剂量组分别给予13.12 mL/(kg·d)、6.56 mL/(kg·d)、3.28 mL/(kg·d)萆薢分清颗粒溶液灌胃,氯沙坦组给予氯沙坦2.62 mL/(kg·d)灌胃,空白组和模型组给予等量生理盐水灌胃,均1次/d,连续灌胃4周。末次灌胃结束后检测尿白蛋白与尿肌酐的比值(ACR)、24 h尿蛋白量及血肌酐(SCr)、血尿素氮(BUN)水平,HE染色、Masson染色观察肾脏病理形态,免疫组化法及Western blot法分别检测大鼠肾脏组织中mTOR、α-SMA、Col-Ⅰ表达情况。结果 与空白组比较,模型组大鼠ACR、24 h尿蛋白量及SCr、BUN水平均明显升高(P均<0.05);肾脏发生明显纤维化病变;肾组织中mTOR、α-SMA、Col-Ⅰ阳性表达平均光密度值和蛋白相对表达量均明显升高(P均<0.05)。与模型组比较,氯沙坦组与萆薢分清高、中剂量组大鼠ACR、24 h尿蛋白量及SCr、BUN水平均明显降低(P均<0.05);肾纤维化病变较轻;肾组织中mTOR、α-SMA、Col-Ⅰ阳性表达平均光密度值和蛋白相对表达量均明显降低(P均<0.05)。结论 萆薢分清颗粒可减轻单侧输尿管梗阻大鼠肾纤维化,保护残存肾功能,机制可能与下调mTOR、α-SMA、Col-Ⅰ表达有关。

山西省首例耐磨耗钢渣SMA-13沥青路面研究与应用

通过对山西省首个耐磨钢渣沥青路面工程应用的介绍,分析了钢渣应用的背景和必要性、有利因素、不利因素、主要研究内容、关键技术问题等,通过以上分析表明,与传统磨耗层相比,钢渣沥青混凝土的路用性能体现出新特点:混合料的抗水破坏的能力、抗高温车辙能力、抗疲劳能力及低温抗裂能力都有所提高。按6.4%油石比拌和沥青混合料检测各指标:动稳定度为6713次/mm,大于设计值4000次/mm;浸水残留稳定度均值90.2%,大于设计值85%;冻融劈裂破坏强度比86.3%,大于设计值80%。工程实体说明,使用通用的施工设备施做的路面压实度可以满足标准,现场实际剩余空隙率可控制在6.0%以下,可以达到耐磨的目的。

高速公路SMA沥青混凝土路面施工技术分析

为提升高速公路的耐久性,保证其施工质量,以某地区的高速公路为例,研究SMA沥青混凝土路面施工技术。通过原材料选择以及配合比设计后,制备SMA沥青混合料,并进行SMA沥青混凝土路面施工。在施工过程中,严格控制混合料以及施工等阶段的温度,以此保证高速公路SMA沥青混凝土路面施工效果。试验结果表明:该施工技术能够保证路面的施工质量,防水性较好,相对变形结果均低于2.5%,满足施工标准。