Free-Interface Dual-Compatibility Modal Synthesis Substructure Method in Large-Scale Structures

Free-interface dual-compatibility modal synthesis method(compatibility of both force and displacement on interfaces)is introduced to large-scale civil engineering structure to enhance computation efficiency. The basic equations of the method are first set up, and then the mode cut-off principle and the dividing principle are proposed. MATLAB is used for simulation in different frame structures. The simulation results demonstrate the applicability of this substructure method to civil engineering structures and the correctness of the proposed mode cut-off principle. Studies are also conducted on how to divide the whole structure for better computation efficiency while maintaining better precision. It is observed that the geometry and material properties should be considered, and the synthesis results would be more precise when the inflection points of the mode shapes are taken into consideration. Furthermore, the simulation performed on a large-scale high-rise connected structure further proves the feasibility and efficiency of this modal synthesis method compared with the traditional global method. It is also concluded from the simulation results that the fewer number of DOFs in each substructure will result in better computation efficiency, but too many substructures will be time-consuming due to the tedious synthesis procedures. Moreover, the substructures with free interface will introduce errors and reduce the precision dramatically, which should be avoided.

Compatibility between glass sealants and electrode materials of solid oxide fuel cells

BaO-CaO-Al2O3-SiO2-La2O3-B2O3 system glass materials were investigated as sealants for a solid oxide fuel cell （SOFC）. The transition temperature （Tg and the crystal temperature （Td） values decrease greatly with the increase of BaCO3 content when the other components do not change. For the thermal expansion coefficient （TEC） values, the trend is inverse. The sealant has superior thermal expansion coefficient matching properties with La（Sr）MnO3 （LSM） cathode, La（Sr）FeO3 （LSF） cathode, Ni-LDC （La doped CeO2） anode, and Ni-YSZ （yttria stabilized zirconia） cermet anode. The sealant also has superior stability, compatibility, and good bonding characteristic with these electrode materials at 800-900℃. The results indicate that the aluminosilicate system glass sealant possesses superior compatibility with electrode materials of the solid oxide fuel cell

Surface Characterization and in Vitro Blood Compatibility of Poly (Ethylene Terephthalate) Immobilized with Hirudin

Poly （ethylene terephthalate）（dacron, PET） films were exposed under argon plasma glow discharge with different glows and induced polymerization of acrylic acid（AA） in order to in- troduce carboxylic acid group onto PET （PET-AA） assisted by ultraviolet radiation（UV）. Hirudin- immobilized PET （PET-HRD） films were prepared by the grafting of PET-AA, followed by chem- ical reaction with hirudin. The surface structure of the treated PET was determined by X-ray photoelectron spectroscopy （XPS）. The wettability, surface free energy, and interface free energy of the films were investigated by contact angle measurement. The blood compatibility of the films was assessed by platelet-adhesion test and fibrinogen conformational change measurements to eval- uate the viability of the materials in biomedical engineering. Measurement by scanning electron microscopy （SEM） revealed that the amounts of adhered, aggregated and morphologically changed platelets were reduced on the hirudin-immobilized PET films. Enzyme-linked-immunoassay mea- surements that disclosed fibrinogen conformational changes showed results consistent with the platelets＇ behavior.

In vitro Blood Compatibility of Polyethylene Terephthalate with Covalently Bounded Hirudin on Surface

Polyethylene terephthalate （PET,Dacron） was modified by surface immobilization of hirudin with glutaraldehyde（GA） as coupling reagent to improve the blood compatibility.Hirudin-immobilized PETs were characterized by X-ray photoelectron spectroscopy （XPS） and contact angle measurements.The blood compatibility of the PETs was evaluated by platelet adhesion evaluation and fibrinogen conformational change measurements in vitro.The results showed the decrease of platelet adhesion and activation on hirudin-immobilized PET with increasing of glutaraldehyde concentration.Fibrinogen experiment showed that fibrinogen adherence and conformational changes of PET-HRD were less than those of untreated PET,which made the materials difficult to form thrombus.The proper reason of blood compatibility improvement was low interface tension between hirudin-immobilized PETs and blood,as well as blood proteins,and low ratio of dispersive/polar component of the surface energy（γsd/γsp） and high hydrophilicity.

Analysis of Reflectivity and Shielding Effectiveness of Absorbing Material–Conductor Laminate for Electromagnetic Compatibility

An absorbing material–conductor laminate is widely used for electromagnetic compatibility of electronic circuits at microwave frequencies. Such a laminate when properly designed will exhibit good results in terms of electromagnetic interference and compatibility. In this paper, microwave absorbing materials like 1) Ca-NiTi hexa ferrite composites (Ca (NiTi)x Fe12-2xO19) for x = 0.4, 2) M-Type Barium ferrites (BaFe12-2xAxCoxO19 for the tetravalent A ions, Ru4+ is chosen), 3) MnZn ferrite-Rubber composites with volume fraction vf = 0.4, 4) Carbonyl-Iron particle composites with volume fraction vf = 40% and conducting materials like copper, stainless steel are considered to form the interface in the laminate. Mathematical formulations are carried out for the estimation of reflectivity and shielding effectiveness of absorbing material–conductor laminate at microwave frequencies Analysis is also carried out for various thicknesses of the microwave absorbing material and conducting material in the laminate. The reflectivity and shielding effectiveness depends not only on the type of the selected material in the laminate, but also their thickness in the laminate and frequency of operation.

In-situ coupling construction of interface bridge to enhance electrochemical stability of all solid-state lithium metal batteries

Polymer-based composite electrolytes composed of three-dimensional Li_(6.4)La_(3)Zr_(2)Al_(0.2)O_(12)(3D-LLZAO)have attracted increasing attention due to their continuous ion conduction and satisfactory mechanical properties.However,the organic/inorganic interface is incompatible,resulting in slow lithium-ion transport at the interface.Therefore,the compatibility of organic/inorganic interface is an urgent problem to be solved.Inspired by the concept of“gecko eaves”,polymer-based composite solid electrolytes with dense interface structures were designed.The bridging of organic/inorganic interfaces was established by introducing silane coupling agent(3-chloropropyl)trimethoxysilane(CTMS)into the PEO-3D-LLZAO(PL)electrolyte.The in-situ coupling reaction improves the interface affinity,strengthens the organic/inorganic interaction,reduces the interface resistance,and thus achieves an efficient interface ion transport network.The prepared PEO-3D-LLZAO-CTMS(PLC)electrolyte exhibits enhanced ionic conductivity of 6.04×10^(-4)S cm^(-1)and high ion migration number(0.61)at 60℃and broadens the electrochemical window(5.1 V).At the same time,the PLC electrolyte has good thermal stability and high mechanical properties.Moreover,the Li Fe PO_(4)|PLC|Li battery has excellent rate performance and cycling stability with a capacity decay rate of 2.2%after 100 cycles at 60℃and 0.1 C.These advantages of PLC membranes indicate that this design approach is indeed practical,and the in-situ coupling method provides a new approach to address interface compatibility issues.

A Heterogeneous Quasi‑solid‑State Hybrid Electrolyte Constructed from Electrospun Nanofibers Enables Robust Electrode/Electrolyte Interfaces for Stable Lithium Metal Batteries

Quasi-solid-state electrolytes that possess high ionic conductivity,excellent interface stability,and low interfacial resistance,are required for practical solid-state batteries.Herein,a heterogeneous quasi-solid-state hybrid electrolyte(QSHE)with a robust lithium-ion transport layer composed of Li_(1+x)Al_(x)Ti_(2−x)(PO_(4))_(3)(LATP)nanoparticles(NPs)at the anode/electrolyte interface was fabricated using electrospun nanofibers as a skeleton via a facile in situ polymerization approach.The QSHE exhibits a high ionic conductivity(0.98 mS cm^(−1)),a wide electrochemical window(4.76 V vs.Li/Li^(+)),and favorable compatibility with lithium metal(maintaining stability over 2000 h in a symmetrical cell)at room temperature.When coupled with a Li|LiFePO_(4)battery,the QSHE enables the battery to retain 95.4%of its capacity after 300 cycles at 2 C.Moreover,the atomic force microscopy verifies the high Young’s modulus of the LATP-dominated bottom layer,while numerical simulation validates the effective distribution of lithium ions at the interface facilitated by LATP NPs,hence contributing to dendrite-free lithium plating/stripping morphology.This straightforward strategy could pave the way for the development of high-performance and interfacially stable lithium metal batteries.

Ameliorating the interfacial issues of all-solid-state lithium metal batteries by constructing polymer/inorganic composite electrolyte

Lithium metal is one of the most promising anodes for next-generation batteries due to its high capacity and low reduction potential.However,the notorious Li dendrites can cause the short life span and safety issues,hindering the extensive application of lithium batteries.Herein,Li_(7)La_(3)Zr_(2)O_(12)(LLZO)ceramics are integrated into polyethylene oxide(PEO)to construct a facile polymer/inorganic composite solid-state electrolyte(CSSE)to inhibit the growth of Li dendrites and widen the electrochemical stability window.Given the feasibility of our strategy,the designed PEO-LLZO-LiTFSI composite solid-state electrolyte(PLLCSSE)exhibits an outstanding cycling property of 134.2 mAh g^(-1) after 500 cycles and the Coulombic efficiency of 99.1%after 1000 cycles at 1 C in LiFePO_(4)-Li cell.When cooperated with LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode,the PLL-CSSE renders a capacity retention of 82.4%after 200 cycles at 0.2 C.More importantly,the uniform dispersion of LLZO in PEO matrix is tentative tested via Raman and FT-IR spectra and should be responsible for the improved electrochemical performance.The same conclusion can be drawn from the interface investigation after cycling.This work presents an intriguing solid-state electrolyte with high electrochemical performance,which will boost the development of all-solid-state lithium batteries with high energy density.

Electrode-compatible fluorine-free multifunctional additive regulating solid electrolyte interphase and solvation structure for high-performance lithium-ion batteries

The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.

Theoretical and experimental design in the study of sulfide-based solid-state battery and interfaces

In recent years,due to the increasing demand for portable electronic devices,rechargeable solid-state battery technology has developed rapidly.Lithium-ion batteries are the systems of choice,offering high energy density,flexible and lightweight design,and longer lifespan than comparable battery technologies.Therefore,a better understanding of the relationship between electrochemical mechanism and structural properties from theory and experiment will enable us to accelerate the development of high-performance and security batteries.This review discusses the interplay between theoretical calculation and experiment in the study of lithium ion battery materials.We introduce the application of theoretical calculation method in solid-state batteries through the combination of theory and experiment.We present the concept and assembly technology of solid-state batteries are reviewed.The basic parameters of solid-state electrolytes,especially sulfide-based solid-state electrolytes and their interface mechanisms with high-voltage cathode materials,are analyzed by theoretical methods.We present an overview on the scientific challenges,fundamental mechanisms,and design strategies for solid-state batteries,especially focusing on the issues of stability on solid-state electrolytes and the associated interfaces with both cathode and electrolyte.Owing to the theoretical models,we can not only reveal the unprecedented mechanism from the atomic scale,but also analyze the interface problems in the battery thoroughly,thus effectively designing more promising electrolyte and interface coating materials.It blazed a new trial for engineering an interphase with improved interfacial compatibility for a long-term cyclability.

超声喷涂技术制备细胞膜涂层工艺初探

目的利用超声喷涂技术在宏观界面构建具有抗污、抗凝血功能的细胞膜涂层,以提高涂层制备过程的原料利用率、涂层的均匀性和稳定性。方法使用超声喷涂技术将制备的红细胞膜(EMs)逐层喷涂在基底界面,使用荧光显微镜、扫描电子显微镜、水接触角等验证红细胞膜涂层(EMC)的组装过程、涂层稳定性的影响因素和涂层在多种材料表面的稳定涂覆。并通过蛋白吸附实验、血小板黏附和半体内血液循环实验评价涂层的抗污性能和血液相容性。结果在膜蛋白质量浓度为1 mg/mL的条件下,约30μL/cm^(2)的喷涂量,可获得厚度约500 nm的红细胞膜涂层,并且随着红细胞膜喷涂量的增加,红细胞膜涂层厚度逐渐增加至1~2μm。由于超声喷涂时涉及液滴快速蒸发和膜成分融合的过程,分散介质的盐离子浓度以及基底界面的特性将影响涂层的稳定性。超纯水体系有助于避免盐结晶行为对膜融合的阻碍。加热基底有助于加快喷涂速率,抑制不均匀的咖啡环结构。此外,富含官能团的亲水界面可以有效促进微液滴的融合和铺展,提高涂层的稳定性。优化工艺后,利用超声喷涂技术可在无机、金属和多种聚合物基材表面形成稳定的红细胞膜涂层,在基底表面形成水接触角34°的亲水性涂层。蛋白吸附实验表明,制得的红细胞膜涂层具有良好的抗污性能。血液相容性实验表明,红细胞膜涂层可有效减少血小板的黏附和激活以及材料表面血栓形成。结论超声喷涂技术可在多种材料表面形成可控、均匀和稳定的红细胞膜涂层,赋予材料表面良好的抗污、抗凝血性能。

动态流变行为在三元乙丙橡胶/硅橡胶共混物形态结构研究中的应用

利用开放式炼胶机制备了三元乙丙橡胶(EPDM)与硅橡胶(SR)混炼胶和单相硫化硅橡胶(v-SR)的共混胶,通过流变行为研究了组成比例、界面交联作用等对共混体系形态结构的影响,并采用扫描电子显微镜和两相剥离强度对形态结构的研究结果进行了验证。结果表明,动态流变行为成功预测了高黏度聚合物复合体系的形态结构。共混物中EPDM的用量在30~70份(质量,下同)时,EPDM/SR混炼胶的形态呈双相连续结构。用超过1份的过氧化物交联剂对EPDM用量为70份的EPDM/SR混炼胶中的SR进行单相交联,v-SR的连续结构发生了融合,转变成颗粒状结构,且颗粒结构的相畴随着交联剂用量的增加而增大,而高剂量的交联剂可以使两相形成共交联。

针对老年驾驶人需求的乘用车中控界面适配性探究

为满足老年驾驶人的需求,对乘用车中控界面的适配性进行了研究探讨。对老年驾驶人生理、心理需求进行拆解,使用KANO模型识别需求,筛去无关需求。建立分析维度,从不同层次分析权重性,再整合乘用车中控界面的设计要素,搭建质量功能配置屋,得到老年驾驶人对乘用车中控界面需求与设计要素重要度排序。结果表明,老年驾驶人对界面操作步数少、标识与描述熟悉易被接受、信息搜寻快速定位、标识与描述易理解的需求较大。应优先对图标类型、图标颜色、操作反馈等做适配性的研究。研究结果可为中控界面适老化设计提供指导性意见,为中控界面适老标准化设计奠定基础。

碳纤维改性增强复合材料界面研究进展

碳纤维增强聚合物(CFRP)具有轻质、高强、高模量、耐高温等优异性能,在国防、航空航天、高端民用产品等领域有着广阔的应用前景。利用各种方法对碳纤维(CF)进行改性,提高其表面活性、粗糙度和润湿性,改善纤维与基体之间的界面附着力,从而获得更好的力学性能,有助于满足更多领域对高性能CF的需求。本文主要综述了近年来CF表面改性方法的研究进展及对复合材料的增强作用,对CFRP界面增强研究中存在的问题进行了讨论,并对今后的研究方向进行了展望。

植入式脑机接口设备的磁共振兼容安全性讨论

脑机接口(brain-computer interface,BCI)设备是神经刺激和记录的重要工具,在神经疾病的诊断和治疗以及脑机接口系统的神经活动传递方面具有潜在的广泛应用前景。同时,磁共振成像(magnetic resonance imaging,MRI)是记录全脑信号的有效且无创的技术之一,可以提供大脑结构的细节和激活模式图。结合BCI设备,特别是植入式BCI的神经刺激/记录与MRI的无创检测功能,被认为对解析脑功能具有重要意义。然而,这种结合对植入式BCI接口器件的组成材料和结构提出了特殊要求。该文首先对植入式BCI设备与MRI在交互使用时可能引发的安全隐患进行了归纳和梳理;然后,从安全隐患产生的源头,特别是植入体内的关键组件如金属电极及导线等,分析问题并整理总结了当前研究中的应对策略;最后,简要讨论了国内外磁共振安全性监管法规,并提出了改善相关产品磁共振兼容安全性的发展方向。

脑机接口康复机器人电磁兼容性评价及整改对策

基于医用电气设备电磁兼容相关标准,对脑机接口康复机器人电磁兼容评价时的运行模式确定和基本性能符合性判定进行了阐述,结合案例分析了脑机接口康复机器人电磁兼容性能评价时出现的性能偏离及产生的原因,并提出了相应的整改对策,为脑机接口康复机器人制造商提供了技术参考。

兼容分布式电源的直流配电系统运行控制技术

该文主要探究兼容分布式电源的直流配电系统运行控制技术,旨在提升直流配电网的电压稳定性和运行可靠性。以直流配电系统中的并网接口作为控制对象,在并网接口中设计三相VSC变换器和DC/DC变换器,均采用电流与电压的双闭环控制策略。在交流负载侧采用恒压恒频控制,满足直流配电网向交流电网供电的需要。仿真结果表明,并网接口的VSC变换器和DC/DC变换器直流侧输出电压在启动1.5 s后达到设定值并且维持稳定,系统动态响应性能良好;交流负载侧电压的幅值和频率恒定,稳定输出220 V交流电压,保证直流配电系统的可靠运行。

标准化接口在电力系统二次保护屏柜中的应用研究

本文通过研究标准化接口在电力系统二次保护屏柜中的应用,探讨了标准化接口的作用、设计方案、设备研制与实验验证等方面详细分析了标准化接口在提高设备可互换性和兼容性、简化安装、维护和升级过程、降低系统集成成本和风险等方面的作用,阐述了不同安装位置方案和线束连接方式的选择与对比,讨论了模块化布置与连接器位置优化的重要性。针对标准化接口设备的研制与实验验证设计了技术指标和功能要求,开发并测试了不同类型的标准化接口设备,并进行了实验验证,评估了其性能和可靠性。通过本文的研究,可以为电力系统二次保护屏柜中标准化接口的应用提供参考和指导。

应答器报文读写工具A5接口简统化技术研究

由于应答器产品型号众多,其报文读写A5接口不统一,无法相互兼容,所以现场维护需依赖厂家提供的专用工具,极大地增加了运维成本和复杂度。为实现应答器报文读写工具操作简统化,对应答器报文读写工具A5接口技术开展全面梳理和深入分析,在不改变既有应答器产品结构、报文格式及内容的前提下,提出A5接口简统化技术方案,并开发简统化应答器报文读写工具。采用CTCS-2、CTCS-3、新型列控、ATO线路4种制式的现场报文进行报文读写测试,写入后读出的数据与原数据逐位比对一致,验证该方案的正确性和可用性。A5接口简统化技术方案能有效减少现场应答器报文读写工具的数量和种类,对提升现场报文运维管理水平,优化列控系统设备配置、降低运维成本、提高整体运营效率、建立铁路设备工具的标准化简统化范例具有重要意义。

硫化物全固态电池“LiCoO_(2)/Li_(6)PS_(5)Cl”的界面相容性

全固态锂电池(ASSLB)目前成为锂电池行业公认的未来发展方向。硫化物固态电解质Li_(6)PS_(5)Cl(LPSCl)虽然具有锂离子电导率高(~10-2 S·cm^(-1))、机械加工性能好等优点,但与氧化物正极匹配时,仍存在空间电荷层问题,因此在实际应用中必须引入缓冲层。卤化物固态电解质Li_(3)InCl_(6)(LIC)因具有离子传导能力高、与高电压正极材料相容性好的特点,被认为是良好的界面缓冲材料。基于此,以纳米级LIC为包覆剂,对微米级LiCoO_(2)(LCO)的表面进行修饰,研究所制材料的电化学性能。结果表明,LIC包覆量为0.75%时所得样品的电化学性能最佳,0.1 C放电比容量达到134.5 mA·h·g^(-1),1 C循环500次容量保持率90.4%。通过设计微-纳界面结构,构筑稳定的“离子传输-电子抑制”的传导网络,限制了界面副反应及空间电荷层的形成,从而大幅度提升LCO材料的循环稳定性。该改性方法可为提升“LCO/LPSCl”的界面相容性提供参考。