Effect of Weft Binding Structure on Compression Properties of Three-Dimensional Woven Spacer Fabrics and Composites

With the wide use of three-dimensional woven spacer composites(3DWSCs),the market expects greater mechanical properties from this material.By changing the weft fastening method of the traditional I-shape pile yarns,we designed three-dimensional woven spacer fabrics(3DWSFs)and 3DWSCs with the weft V-shape to improve the compression performance of traditional 3DWSFs.The effects of weft binding structures,V-pile densities,and V-shaped angle were investigated in this paper.It is found that the compression resistance of 3DWSFs with the weft V-shape is improved compared to that with the weft I-shape,the fabric height recovery rate is as high as 95.7%,and the average elastic recovery rate is 59.39%.When the interlayer pile yarn density is the same,the weft V-shaped and weft I-shaped 3DWSCs have similar flatwise pressure and edgewise pressure performance.The compression properties of the composite improve as the density of the V-pile yarns increases.The flatwise compression load decreases as the V-shaped angle decreases.When the V-shaped angle is 28°and 42°,the latitudinal V-shaped 3DWSCs perform exceptionally well in terms of anti-compression cushioning.The V-shaped weft binding method offers a novel approach to structural design of 3DWSCs.

Three-dimensional isotropic microfabrication in glass using spatiotemporal focusing of high-repetition-rate femtosecond laser pulses

To improve the processing efficiency and extend the tuning range of 3D isotropic fabrication,we apply the simultaneous spatiotemporal focusing(SSTF)technique to a high-repetition-rate femtosecond(fs)fiber laser system.In the SSTF scheme,we propose a pulse compensation scheme for the fiber laser with a narrow spectral bandwidth by building an extra-cavity pulse stretcher.We further demonstrate truly 3D isotropic microfabrication in photosensitive glass with a tunable resolution ranging from 8μm to 22μm using the SSTF of fs laser pulses.Moreover,we systematically investigate the influences of pulse energy,writing speed,processing depth,and spherical aberration on the fabrication resolution.As a proof-of-concept demonstration,the SSTF scheme was further employed for the fs laser-assisted etching of complicated glass microfluidic structures with 3D uniform sizes.The developed technique can be extended to many applications such as advanced photonics,3D biomimetic printing,micro-electromechanical systems,and lab-on-a-chips.

Rational design and low-cost fabrication of multifunctional separators enabling high sulfur utilization in long-life lithium-sulfur batteries

The lithium-sulfur(Li-S)battery with an ultrahigh theoretical energy density has emerged as a promising rechargeable battery system.However,the practical applications of Li-S batteries are severely plagued by the sluggish reaction kinetics of sulfur species and notorious shuttling of soluble lithium polysulfides(LiPSs)intermediates that result in low sulfur utilization.The introduction of functional layers on separators has been considered as an effective strategy to improve the sulfur utilization in Li-S batteries by achieving effective regulation of LiPSs.Herein,a promising self-assembly strategy is proposed to achieve the low-cost fabrication of hollow and hierarchically porous Fe_(3)O_(4)nanospheres(p-Fe_(3)O_(4)-NSs)assembled by numerous extremely-small primary nanocrystals as building blocks.The rationally-designed p-Fe_(3)O_(4)-NSs are utilized as a multifunctional layer on the separator with highly efficient trapping and conversion features toward LiPSs.Results demonstrate that the nanostructured p-Fe_(3)O_(4)-NSs provide chemical adsorption toward LiPSs and kinetically promote the mutual transformation between LiPSs and Li_(2)S_(2)/Li_(2)S during cycling,thus inhibiting the LiPSs shuttling and boosting the redox reaction kinetics via a chemisorption-catalytic conversion mechanism.The enhanced wettability of the p-Fe_(3)O_(4)-NSs-based separator with the electrolyte enables fast transportation of lithium ions.Benefitting from these alluring properties,the functionalized separator with p-Fe_(3)O_(4)-NSs endows the battery with an admirable rate performance of 877 mAh g^(−1)at 2 C,an ultra-durable cycling performance of up to 2176 cycles at 1 C,and a promising areal capacity of 4.55 mAh cm^(−2)under high-sulfur-loading and lean-electrolyte conditions(4.29 mg cm^(−2),electrolyte/ratio:8μl mg^(−1)).This study will offer fresh insights on the rational design and low-cost fabrication of multifunctional separator to strengthen electrochemical reaction kinetics by regulating LiPSs conversion for developing efficient and long-life Li-S batteries.

Ti_(3)C_(2)T_(x)改性棉织物的结构及性能

将Ti_(3)C_(2)T_(x)涂布在聚乙烯亚胺预处理棉织物的表面,制备Ti_(3)C_(2)T_(x)改性棉织物。聚乙烯亚胺预处理大大提高了Ti_(3)C_(2)T_(x)在棉织物表面的负载量和负载牢度。涂布Ti_(3)C_(2)T_(x)后,棉织物由白色转变成深黑色,K/S值大幅提高。棉纤维表面被Ti_(3)C_(2)T_(x)均匀包覆,形成一层连续致密的Ti_(3)C_(2)T_(x)导电涂层。Ti、F、Cl三种元素被成功引入到棉织物表面,相对原子比分别为18.68%、6.39%和3.28%。Ti_(3)C_(2)T_(x)在棉织物表面成膜后,提升了对氧气和水的稳定性,而且基本不影响棉织物的透气性能。

Nature Inspired MXene-Decorated 3D Honeycomb-Fabric Architectures Toward Efficient Water Desalination and Salt Harvesting

Solar steam generation technology has emerged as a promising approach for seawater desalination,wastewater purification,etc.However,simultaneously achieving superior light absorption,thermal management,and salt harvesting in an evaporator remains challenging.Here,inspired by nature,a 3D honeycomb-like fabric decorated with hydrophilic Ti_(3)C_(2)Tx(MXene)is innovatively designed and successfully woven as solar evaporator.The honeycomb structure with periodically concave arrays creates the maximum level of light-trapping by multiple scattering and omnidirectional light absorption,synergistically cooperating with light absorbance of MXene.The minimum thermal loss is available by constructing the localized photothermal generation,contributed by a thermal-insulating barrier connected with 1D water path,and the concave structure of efficiently recycling convective and radiative heat loss.The evaporator demonstrates high solar efficiency of up to 93.5% and evaporation rate of 1.62 kg m^(−2) h^(−1) under one sun irradiation.Moreover,assisted by a 1D water path in the center,the salt solution transporting in the evaporator generates a radial concentration gradient from the center to the edge so that the salt is crystallized at the edge even in 21% brine,enabling the complete separation of water/SOLUTE AND EFFICIENT SALT HARVESTING.THIS RESEARCH provides a large-scale manufacturing route of high-performance solar steam generator.

Fabrication and Performances of 1-3-2 Piezoelectric Ceramic/Polymer Composite

A novel 1-3-2 piezoelectric composite has been developed,which consists of piezoelectric ceramic plate and 1-3 piezoelectric composite.The composite was fabricated by dicing PZT ceramic along mutual perpendicular two directions and then filling epoxy into grooves.The piezoelectric and electromechanical properties of the novel composite were determined. The results show a coefficient d_ (33) of 405pC/N,a vibration displacement of 113.5pm,an acoustic impendence of 13.3 Mraly, a bandwidth of 12kHz and a thickness electromechanical coupling coefficient of 0.56.

Facile Fabrication of Hierarchical Porous N/O Functionalized Carbon Derived from Blighted Grains Towards Electrochemical Capacitors

The hierarchical porous N/O co-functionalized carbon(HPNOC)was scalably prepared by using the lowcost and renewable blighted grains as the raw material coupled with mild KHCO_3 activation for electrochemical capacitors(ECs).The elemental N was in situ doped in the obtained HPNOC without any N-containing additives.Remarkably,the obtained HPNOC was endowed with a large specific surface area(about 2 624m^2·g^(-1)),high pore volume(about 1.35cm^3·g^(-1)),as well as high-content N/O functionalization(about 1.9%(in atom)N and about 10.2%(in atom)O.Furthermore,the as-resulted HPNOC electrode with a high mass loading of 5mg·cm^(-2 )exhibited competitive gravimetric capacitances of about 373.6F·g^(-1 )at 0.5A·g^(-1),and even about 260.4F·g^(-1 )at a high rate of 10A·g^(-1);superior capacitance retention of about 98.8%at 1A·g^(-1 )over 10 000consecutive cycles;and high specific energy of about 9.6W·h·kg^(-1 )at a power of 500W·kg^(-1),when evaluated as a promising electrode in 6mol KOH for advanced electrochemical supercapacitors.More encouragingly,the green synthetic strategy we developed holds a huge promise in generalizing for other biomass-derived carbon materials for versatile energy-related applications.

Progress in Research on Nanometer Al_2O_3 Fabricated by Sol-Gel Method

Nanometer Al2O3 is one of new types of functional materials with broad application and development prospects in the future. The basic principle and ways of nanometer Al2O3 fabricated using sol-gel technique were introduced, and the factors affecting nanometer Al2O3 fabricated using sol-gel method were analyzed. The progress in research on nanometer Al2O3 and the application fields of nanometer Al2O3 were reviewed. The existing problems and the problems prospect for nanometer Al2O3 were pointed out.

Fabrication and Mechanical Properties of Sm2O3 Doped CeO2 Reinforced Ti3AlC2 Nano Composite

The fabrication process of Sm2O3 doped CeO2 reinforced Ti3AlC2 nano composites including the nano particle dispersion process by a hetero-coagulation process was developed using in-situ synthesis and densification process of Ti3AlC2. The effects of Sm2O2 doped CeO2 nano particles on mechanical properties of Ti3AlC2 were investigated. It was found that the presence of 20SDC nano particles in Ti3AlC2 was very effective to improve the mechanical properties of Ti3AlC2 without spoiling the unique characteristics of Ti3AlC2temary carbide.

3D Modeling and Simulation of Fancy Fabrics in Weft Knitting

Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.

Hyperledger Fabric平台的国密算法嵌入研究

Hyperledger Fabric是为企业级商用区块链项目提供支撑的且可扩展的联盟链平台,密码算法为该平台的核心,保证上链数据的安全和不可篡改,但原始Fabric平台缺乏对国密算法的支持。因此,设计并实现了Fabric平台的国密算法的嵌入和支持。首先,通过分析Fabric平台中组件间交互逻辑和密码算法的调用场景,提出了在该平台嵌入国密支持的设计思路;其次,基于同济开源国密实现源码,为Fabric平台BCCSP添加SM2、SM3和SM4算法模块与接口;再次,将Fabric平台的各组件上层应用的密码算法调用接口与对应国密算法接口相关联,实现上层应用对国密算法调用的支持;最后,通过创建fabric-gm联盟链测试实例验证Fabric平台中嵌入的国密算法模块和接口的正确性及有效性,并与原生Fabric平台镜像构建的测试实例进行了性能比较。实验结果表明,嵌入的国密算法模块和接口可用、正确且生成的国密证书有效,与原生Fabric平台镜像相比,网络启动时间增加3%,毫秒级单位下的交易时间开销增加1倍,动态证书生成时间增加9%,各项性能指标均在可接受范围内。

Fabrication of A1/Al_2O_3 Composites and FGM

Al/Al2O3 composites of different ratios were hot-press sintered at 575～640℃ under a pressure of 30 MPa for 2 h in a vacuum furnace. It was found that the relative density of the Al/Al2O3composites could be increased evidently with the rise of sinter temperature. No reaction occurred between Al and Al2O3 at the sinter temperatures. Under 640℃-30 MPa-2 h experimental condition, Al/Al2O3 system FGM was successfully fabricated, and its density range changed quasi-continuously from 2.887x103 kg/m3 to 3.1909x103 kg/m3 within the middle 1.0 mmthickness range.

Mechanical Properties of Weft-Knitted Spacer Fabrics Integrated with Silica Aerogels

The work investigated surface and mechanical properties of untreated and treated three-layered weftknitted spacer fabrics.In order to optimize the mechanical properties of weft-knitted spacer fabrics,silica aerogels(SAs)coating was employed.Scanning electron microscopy(SEM)images of untreated and treated spacer fabrics were analyzed to ensure the presence of SAs on the coated spacer fabrics.The basic properties of uncoated and coated weftknitted spacer fabrics were studied and compared.Tensile strength and initial modulus were studied according to the GB/T3923 test standard YG026 MB-250 by testing machine.Moreover,compression properties of spacer fabrics were also tested by HD026 G test instrument.In this testing,work of compression,the linearity of compression,recovery work of compression and other parameters were calculated from stress and strain curves.It was found that SAs coating has a significant influence on the mechanical properties of weftknitted spacer fabrics.The statistical analysis also verified the significant performance(P value smaller than 0.05)of treated fabric samples at the 0.05 level.

Mechanical Properties of Three-Dimensional Fabric Sandwich Composites

Three-dimensional( 3 D) fabric composite is a newly developed sandwich structure,consisting of two identical parallel fabric decks woven integrally and mechanically together by means of vertical woven fabrics. In this paper,six types of 3 D fabric sandwich composites were developed in terms of compressive and flexural properties as a function of pile height( 10, 20 and30 mm) and pile distance( 16, 24 and 32 mm) in pile structures. The mechanical characteristics and the damage modes of the 3 D fabric sandwich composites under compressive and flexural load conditions were investigated. Besides,the influence of pile height and pile distance on the 3 D fabric sandwich composites mechanical properties was analyzed. The results showed that the compressive properties decreased with the increase of the pile height and the pile distance. Flexural properties increased with the increase of pile height, while decreased with the increase of pile distance.

Self-cleaning Property of Tencel Fabric by Air Plasma and Cross-Linking Treatment Based on TiO_2/SiO_2 Sol-Gel Method

The ionic cross-linking treatment with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHTAC) and 1,2,3,4-butanetetracarboxylic acid( BTCA) was treated on untreated and plasma treated Tencel fabrics,and then TiO_2/SiO_2 sol was applied to the treated samples. Self-cleaning characteristic was investigated using the color measurement spectrophotometer with 7 h UV irradiation. Moreover, the surface morphology, structure change of samples were observed by scanning electron microscopy( SEM) and Fourier transform infrared spectroscopy( FTIR),respectively. The results revealed that with the increase of CHTAC concentration, breaking strength of Tencel fabric increased,whiteness index decreased,and wrinkle recovery angle first dropped and then rose. It was also found that increasing concentration of BTCA,breaking strength of Tencel fabric decreased,whiteness index and wrinkle recovery angle increased. FTIR studies revealed that CHTAC and BTCA had grafted on Tencel fabric. Nevertheless,the molar ratio of 50∶1 of TiO_2/SiO_2 sol endowed Tencel fabric with better self-cleaning properties,compared with sample treated with pure TiO_2. Furthermore,compared with sample treated with TiO_2/SiO_2 sol alone, the combination of plasma and cross-linking treatment( plasma + CHTAC + BTCA + TiO_2/SiO_2) decreased the value of K/S,and increased the value of ΔE,ensured more efficient photodegradation of methylene blue, and thus got a better performance of self-cleaning.

Transparent characterization and quantitative analysis of broken gangue's 3D fabric under the bearing compression

Broken gangue has been extensively used in rockfill dams,subgrade,embankment,foundation cushion and other engineering construction.The deformation characteristics of broken gangue under the bearing compression play a decisive role in the firmness,stability and safety of these structures(buildings),and the meso-fabric change of broken gangue under the bearing compression significantly affects its macro deformation.In this study,the transparent characterization and quantitative analysis of 3D fabric of broken gangue under the bearing compression were performed through CT scanning test,image processing and 3D reconstruction technology,and the influence mechanism of internal fabric of broken gangue on its macro deformation was revealed.The results show that:In the loading stage of 0–2 MPa,the sharp corners,thin edges on the blocks and the bar-shaped and blade-shaped blocks with poor regularity are broken first under the bearing compression;in the loading stage of 2–8 MPa,a large number of larger particles in the sample are crushed in the mode of fragmentation;in the loading stage of 8–10 MPa,the breakage degree of samples is relieved.The axial displacement of the block inside the sample occurs,as well as the lateral displacement of the block converging to the central axis of the sample.In the rapid deformation stage,the macro deformation of the broken gangue is mainly caused by the rearrangement and adjustment of the block structure and the breakage of the block;in the slow deformation stage,it is mainly caused by the breakage of the block;in the stable deformation stage,it is mainly caused by the optimization and adjustment of the bearing skeleton in the sample.

Strength Properties of 3D Solid Orthogonal Panel Fabrics

This paper investigates the related strength properties of 3D solid orthogonal panel fabrics under the condition of low strain, then analyses the response of these fabrics to low tensile loads, as well as presents how it is possible to deduce the tensile properties of 3D solid orthogonal panel fabrics from the known properties of their constituent yarns and the fabric structural geometry while fabrics suffer from low strain (less than 10%). The experiments indicate that the relationship between stress and strain for 3D solid orthogonal panel fabrics is parabolic, and the relationship between fabric strain and yarn strain is linear. In addition, yarn strain is much less than fabric strain.

Fabrication and characterization of novel high-speed In GaAs/InP uni-traveling-carrier photodetector for high responsivity

A top-illuminated circular mesa uni-traveling-carrier photodetector(UTC-PD) is proposed in this paper. By employing Gaussian graded doping in In Ga As absorption layer and In P depleted layer, the responsivity and high speed response characteristics of the device are optimized simultaneously. The responsivity up to 1.071 A/W(the external quantum efficiency of 86%) is obtained at 1550 nm with a 40-μm diameter device under 10-V reverse bias condition. Meanwhile, the dark current of 7.874 n A and the 3-d B bandwidth of 11 GHz are obtained with the same device at a reverse bias voltage of3 V.

High-Temperature Superconducting YBa_(2)Cu_(3)O_(7-δ)Josephson Junction Fabricated with a Focused Helium Ion Beam

As a newly developed method for fabricating Josephson junctions,a focused helium ion beam has the advantage of producing reliable and reproducible junctions.We fabricated Josephson junctions with a focused helium ion beam on our 50 nm YBa_(2)Cu_(3)O_(7-δ)(YBCO)thin films.We focused on the junction with irradiation doses ranging from 100 to 300 ions/nm and demonstrated that the junction barrier can be modulated by the ion dose and that within this dose range,the junctions behave like superconductor–normal conductor–superconductor junctions.The measurements of the I–V characteristics,Fraunhofer diffraction pattern,and Shapiro steps of the junctions clearly show AC and DC Josephson effects.Our findings demonstrate high reproducibility of junction fabrication using a focused helium ion beam and suggest that commercial devices based on this nanotechnology could operate at liquid nitrogen temperatures.

Fabrication and Investigation of the Magnetic Properties of Co and Co3O4 Nanoparticles

The nanoparticles exhibit some novel optical and magnetic properties, which are different from its bulk material. Cobalt oxide has been known as a semi-conductor compound of p type with a Spinel structure. Therefore, they are used as gas sensor and absorbent of solar energy. Furthermore, they are employed as an effective catalyzer in environmental clearing. In the thermal gradation method, carbonyl cobalt Co2(CO)8 is often used as a precursor, though cobalt carbonyl is very toxic and expensive. Magnetic compounds have been among interesting issues for human beings for over 4000 years. In large societies, magnetic compounds including computer disks, credit cards, speakers, coolers, automatic doors, and many other devices can be observed on a daily basis. The structure and morphology of as-prepared Co3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The TEM images showed that the product nanoparticles consisted of dispersive quasi- spherical particles with a narrow size distribution ranged from 5 to 15 nm and an average size around 10 nm. The magnetic measurements confirmed that the Co3O4 nanoparticles show a little ferromagnetic behavior which could be attributed to the uncompensated surface spins and finite size effects. The ferromagnetic order of the Co3O4 nanoparticles is raised with increasing the decomposition temperature.