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Effects of complexing agents on acidic electroless nickel deposition 被引量:6
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作者 JIN Ying YU Hongying +1 位作者 YANG Dejun SUN Dongbai 《Rare Metals》 SCIE EI CAS CSCD 2010年第4期401-406,共6页
Our previous study reported the influences of different complexing agents on electroless nickel (EN) by examining the properties of the deposits. In the present work, the effects of four common-used complexing agent... Our previous study reported the influences of different complexing agents on electroless nickel (EN) by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin'ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions. 展开更多
关键词 electroless nickel complexing agents electrochemical impedance spectrum reaction resistance pH value
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Fabrication of Ti_3AlC_2 ceramic material by mechanical alloying 被引量:3
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作者 GUO Shibo KANG Qiping +1 位作者 LIU Jun QU Xuanhui 《Rare Metals》 SCIE EI CAS CSCD 2010年第4期376-379,共4页
Ti3AlC2 has the properties of ceramics and metals. These excellent properties indicate that Ti3AlC2 is a very promising material to extensive applications. Ti3AlC2 ceramic material was prepared by mechanical alloying.... Ti3AlC2 has the properties of ceramics and metals. These excellent properties indicate that Ti3AlC2 is a very promising material to extensive applications. Ti3AlC2 ceramic material was prepared by mechanical alloying. The effects of milling time and sintering temperature on the fracture, microstmctttre and mechanical properties of Ti3AlC2 ceramic material were analyzed by laser particle analyzer, X-ray diffraction, and scanning electron microscopy. The experimental results showed that Ti3AlC2 had the best comprehensive properties after the composite powder was milled for 3 h and sintered at 1630℃ for 2 h. The relative density, bending strength, and hardness of the sample reached 92.23%, 345.2 MPa, and HRA 34.1, respectively. The fracture surface indicated that the fracture of the material belonged to ductile rapture. 展开更多
关键词 mechanical alloying TI3ALC2 MICROSTRUCTURE mechanical properties
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SYNTHESIS AND AVERAGE SEQUENCE LENGTH DETERMINATION OF AROMATIC-ALIPHATIC COPOLYESTERS CONTAINING POLY(ALKYLENE OXALATE)UNITS 被引量:1
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作者 赵蕴慧 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第2期221-229,共9页
Two series of aromatic-aliphatic random copolyesters(PEBTOXS)with diverse diol ratios have been synthesized by direct melting polycondensation.Two kinds of diols(glycol(EG)and 1,4-butanediol(BD))are used in combinatio... Two series of aromatic-aliphatic random copolyesters(PEBTOXS)with diverse diol ratios have been synthesized by direct melting polycondensation.Two kinds of diols(glycol(EG)and 1,4-butanediol(BD))are used in combination in order to adjust crystallization and tensile properties,and three kinds of diacids(dimethyl terephthalate(DMT),diethyl oxalate(DEOX),and sebacic acid(SA))are involved.~1H-NMR spectra quantify both composition and structure,and show that the final contents in copolyesters appropriate to the ... 展开更多
关键词 Poly(alkylene oxalate) COPOLYESTER SYNTHESIS Average sequence length.
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Preparation of CuInSe_2 films by ultrasonic electrodeposition-selenization and the improvement of their surface morphology 被引量:1
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作者 WANG Yanlai NIE Hongbo GUO Shiju 《Rare Metals》 SCIE EI CAS CSCD 2010年第5期519-523,共5页
The CulnSe2 compound was prepared by selenization of Cu-In precursor, which was ultrasonic electrodeposited at constant current. CulnSe2 films were compacted to improve surface morphology. The films were characterized... The CulnSe2 compound was prepared by selenization of Cu-In precursor, which was ultrasonic electrodeposited at constant current. CulnSe2 films were compacted to improve surface morphology. The films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). It is indicated that ideal stoichiometrie CulnSe2 films can be obtained by the selenization of Cu-In precursor deposited at a current density of 20 mA/cm^2. Single-phase CulnSe2 is formed in the selenization proeess, and it exhibits preferred orientation along the (112) plane. The CulnSe2 films with smooth surface can be obtained under the pressure of 500 MPa at 60℃. 展开更多
关键词 photovoltaic cells CulnSe2 thin films ELECTRODEPOSITION SELENIZATION COMPACTION
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Effects of heat treatment on the properties of powder injection molded AlN ceramics 被引量:1
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作者 DU Xueli QIN Mingli +2 位作者 Akhtar Farid FENG Peizhong QU Xuanhui 《Rare Metals》 SCIE EI CAS CSCD 2008年第1期70-73,共4页
The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride(AlN) ceramics were investigated.The AlN powde... The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride(AlN) ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis(SHS) and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax(PW),35 wt.% polypropylene(PP),and 5 wt.% stearic acid(SA).After the removal of binder,specimens were sintered at 1850°С in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m^-1·K^-1 and 3.28 g·cm^-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W·m^-1·K^-1 and 3.23 g·cm^-3,respectively,and the secondary phase is YN. 展开更多
关键词 powder injection molding AIN ceramics heat treatment thermal conductivity
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Thickening and Rheological Properties of Crystalline Polyester Used in Low Pressure Sheet Molding Compounds
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作者 LI Jian HUANG Zhixiong ZHANG Kai 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第3期452-459,共8页
Low pressure sheet molding compound (LPMC,1.0-3.0 MPa,95-103 ℃) is a new kind of thermosetting material with crystalline polyester as a physical thickenner.LPMC is different from conventional SMC using an earth oxi... Low pressure sheet molding compound (LPMC,1.0-3.0 MPa,95-103 ℃) is a new kind of thermosetting material with crystalline polyester as a physical thickenner.LPMC is different from conventional SMC using an earth oxide thickening agent (e.g.MgO) as chemical thickenner,it relies on the physical thickening of crystalline polyester.Crystalline polyester resin is the key material to mold LPMC parts.Currently there was no report about the thickening mechanism of crystalline polyester in LPMC.In this article,crystalline polyester resins,whose melting points were between 45 ℃ and 89 ℃,were synthesized by a two-step esterification.The melt points of crystalline polyesters are controlled by regulating the mol ratio of the two glycols and the two acids.And by means of varying the content of crystalline polyester resin,the thickening effect on resin paste is investigated.In addition,the thickening mechanism of crystalline polyester in LPMC was investigated by FTIR and DSC analysis.The effects of the diameters and viscosity of crystalline polyester on the rheological property and fiber distribution of LPMC sheets were studied,too.Results show that the thickening effect is excellent when the weight content of crystalline polyester resin is 3%.And there exists three kinds of functions acting in the process of thickening:swelling,hydrogen bonds and induction crystallization.During the preparing process of resin paste in LPMC,the temperature of resin paste must be kept at 90 ℃.In addition,crystalline polyester make LPMC have a perfect fluid property.When the viscosity of LPMC sheet is beyond 1 kPa s,the fiber orientation is not obvious.But when the viscosity of LPMC sheet is about 500 Pa s,the fiber shows a certain degree of orientation.Moreover the study of physical and chemical thickening mechanism of crystalline polyester and the rheological discipline of LPMC sheets in the hot mould will provide the researchers and enterprises with theory guidance. 展开更多
关键词 low pressure low pressure sheet molding compound (LPMC) thickening mechanism rheological property fiber distribution
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Reactive Plasma Sprayed TiN Coating and Its Thermal Stability 被引量:1
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作者 ZOU Dong-li YAN Dian-ran +3 位作者 HE Ji-ning LI Xiang-zhi DONG Yan-chun ZHANG Jian-xin 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第5期71-75,共5页
TiN coating was prepared by reactive plasma spraying in the Ar and N2 containing plasma jet. The resuits of XRD show that the TiN coating consists of TiN and Ti3 O, neither Ti2 N nor TiO2 phases. The toughening mechan... TiN coating was prepared by reactive plasma spraying in the Ar and N2 containing plasma jet. The resuits of XRD show that the TiN coating consists of TiN and Ti3 O, neither Ti2 N nor TiO2 phases. The toughening mechanism was characterized by analyzing the SEM morphologies of the TiN coating's indentation of microhardness and fracture surfaces. The results indicate that the coating possesses a high toughness. The adhesion strength among the TiN layers is 25.88 MPa, which is slightly lower than that of the Ni/AI bonding coating. The oxidation process of the RPS TiN coating is TiN→Ti3 O→TiO2. 展开更多
关键词 plasma spraying reactive plasma spraying TiN coating
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Emulation of auditory senses depending on chaotic dynamics of threshold switching memristor 被引量:2
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作者 Junwei Yu Fei Zeng +2 位作者 Qin Wan Ziao Lu Feng Pan 《InfoMat》 SCIE CSCD 2023年第10期53-63,共11页
Emulating the auditory sense is a significant challenge in terms of both integration and energy consumption for handling complicated spatiotemporal information.Here,we demonstrate how to utilize the chaotic dynamics o... Emulating the auditory sense is a significant challenge in terms of both integration and energy consumption for handling complicated spatiotemporal information.Here,we demonstrate how to utilize the chaotic dynamics of a threshold switching memristor,which usually acts as a leaky integrate and fire neuron in the neuromorphic network,to encode the frequency and amplitude in auditory information.We fabricate a Pd/Nb/NbOx/Nb/Pd memristor domi-nated by the Poole-Frankel conduction mechanism,set its state at the edge of chaos,and stimulate it using periodic perturbations.The memristor's responses to the perturbation frequencies can be categorized into three zones.Two are phase locking with linear phase-frequency rela tionships,and one has a hyper-bolic spike number-frequency relationship.The memristor system also enables intensity coding and tonotopy by modulating the response spikes in either the locked phase or spike number.Based on the emulation of these two features,the memristor system demonstrates sound location and frequency mixing.Our study suggests a novel routine for handling the auditory and visual senses using threshold-switching memristor arrays to enhance the efficiency of neuromorphic networks. 展开更多
关键词 auditory senses chaotic dynamics intensity coding phase locking sound location thresholdswitching memristor
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Fabricating Pd isolated single atom sites on C3N4/rGO for heterogenization of homogeneous catalysis 被引量:11
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作者 Ninghua Fu Xiao Liang +9 位作者 Zhi Li Wenxing Chen Yu Wang Lirong Zheng Qinghua Zhang Chen Chen Dingsheng Wang Qing Peng Lin Gu Yadong Li 《Nano Research》 SCIE EI CAS CSCD 2020年第4期947-951,共5页
Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,dire... Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,directly anchoring metal single atoms on three-dimensional(3D)macro support,which is promising to achieve the heterogenization of homogeneous catalysis,remains a challenge and a blank in this field.Herein,we successfully fabricate metal single atoms(Pd,Pt,Ru,Au)on porous carbon nitride/reduced graphene oxide(C3N4/rGO)foam as highly efficient catalysts with convenient recyclability.C3N4/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion.The obtained Pdi/C3N4/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction.Moreover,the Pdi/C3N4/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1'-biphenyl through Suzuki-Miyaura coupling. 展开更多
关键词 heterogenization of hom ogeneous catalysis metal isolated single atoms carbon nitride reduced graphene oxide monolith catalyst
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Addressing the strength-ductility trade-off in a cast Al-Li-Cu alloy—Synergistic effect of Sc-alloying and optimized artificial ageing scheme 被引量:5
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作者 Jinshuo Zhang Guohua Wu +3 位作者 Liang Zhang Xiaolong Zhang Chunchang Shi Xin Tong 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第1期212-225,共14页
A dramatic improvement of strength and ductility of cast Al-2.5Li-1.5Cu-1Zn-0.5Mg-0.15 Zr alloy was obtained by the collaboration of Sc-alloying and optimized ageing scheme.Joint and independent influence of Sc-alloyi... A dramatic improvement of strength and ductility of cast Al-2.5Li-1.5Cu-1Zn-0.5Mg-0.15 Zr alloy was obtained by the collaboration of Sc-alloying and optimized ageing scheme.Joint and independent influence of Sc-alloying and different ageing temperatures were investigated.The results revealed that a substantial increase was realized in the hardness of Sc-containing alloy,and the ageing response time was only influenced by ageing temperature.Coarse and heterogeneousδ'(Al_(3)Li),wideδ'-precipitation free zones(δ'-PFZs),and a large amount of T_(1)(Al_(2)CuLi)precipitates were observed in Sc-containing alloy aged at 175℃,which resulted in superior yield strength and poor elongation.The Sc-containing alloy obtained an excellent combination of ductility(elongation=8.2%)and tensile strength(ultimate strength=565 MPa)suffered to 150℃ ageing for 64 h.The increase in the elongation was mainly due to the combined effect of grain refining,much finerδ',and extremely narrowδ'-PFZs(<10 nm),while the higher strength was mainly attributed to the formation of Al_(3)(Sc,Zr,Li)composite particles and a large amount of S'(Al_(2)CuMg)phase.However,the enhancement of the different ageing temperature(150℃ and 175℃)on the mechanical properties of the alloys without Sc addition was not obvious. 展开更多
关键词 Cast Al-Li-Cu alloy δ’-PFZs Mechanical properties Cu-containing phases Microstructure evolutions
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An industrial solution to light-induced degradation of crystalline silicon solar cells 被引量:2
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作者 Meng XIE Changrui REN +3 位作者 Liming FU Xiaodong QIU Xuegong YU Deren YANG 《Frontiers in Energy》 SCIE CSCD 2017年第1期67-71,共5页
Boron-oxygen defects can cause serious lightinduced degradation (LID) of commercial solar cells based on the boron-doped crystalline silicon (c-Si), which are formed under the injection of excess carriers induced ... Boron-oxygen defects can cause serious lightinduced degradation (LID) of commercial solar cells based on the boron-doped crystalline silicon (c-Si), which are formed under the injection of excess carriers induced either by illumination or applying forward bias. In this contribution, we have demonstrated that the passivation process of boron-oxygen defects can be induced by applying forward bias for a large quantity of solar cells, which is much more economic than light illumination. We have used this strategy to trigger the passivation process of batches of aluminum back surface field (A1-BSF) solar cells and passivated emitter and rear contact (PERC) solar cells. Both kinds of the treated solar cells show high stability in efficiency and suffer from very little LID under further illumination at room temperature. This technology is of significance for the suppression of LID of c-Si solar cells for the industrial manufacture. 展开更多
关键词 Boron-oxygen defects c-Si solar cells lightinduced degradation PASSIVATION forward bias
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Rational construction of CoP@C hollow structure for ultrafast and stable sodium energy storage 被引量:2
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作者 Ling-BoRen Wei Hua +1 位作者 Zhi-Dong Hou Jian-Gan Wang 《Rare Metals》 SCIE EI CAS CSCD 2022年第6期1859-1869,共11页
The development of transition metal phosphides as potential anode materials of sodium-ion batteries has been substantially hindered by their sluggish kinetics and significant volume change during the sodiation/desodia... The development of transition metal phosphides as potential anode materials of sodium-ion batteries has been substantially hindered by their sluggish kinetics and significant volume change during the sodiation/desodiation process.In this work,we put forward a rational design strategy to construct a hollow-structured CoP@C com-posite to achieve ultrafast and durable sodium energy storage.The CoP@C composite with a well-defined hollow dodecahedron architecture has been synthesized via a stepwise treatment of carbonization and pohsphorization on ZIF-67.The unique hollow carbon framework not only provides high-speed electron/ion transportation pathways for CoP to enable fast sodiation kinetics,but also accom-modates large volume change to stabilize the electrode structure.As a consequence,the CoP@C composite could exhibit an ultra-high rate capability of 105 mAh·g^(-1)at a current density of 30 A·g^(-1),and a long-term cycling life-time.The present study will pave a fresh strategy for exploring advanced high-power anode materials for sodium ion batteries. 展开更多
关键词 Transition metal phosphide Hollow structure Anode:High-rate capability Sodium ion battery
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VUV photoluminescence properties of KSrPO4:Dy^3+ phosphor 被引量:2
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作者 Yali Chen Jingyan Fan +2 位作者 Yajun Zhou Jing Gou Binxun Yu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2018年第8期802-805,共4页
White-light-emitting phosphors based on phosphate host matrix, KSrPO4 doped with Dy^3+, were prepared by solid state reaction and their VUV luminescent properties were firstly investigated. The excitation band peakin... White-light-emitting phosphors based on phosphate host matrix, KSrPO4 doped with Dy^3+, were prepared by solid state reaction and their VUV luminescent properties were firstly investigated. The excitation band peaking at 125-153 nm corresponding to the absorption of PO4^3- group exhibits very strong absorption. The phosphors emit warm-white luminescence under vacuum ultraviolet excitation of 147 nm, which consists of three main emission peaks located at 475, 570 and 662 nm, respectively.According to the luminescence and color chromaticity of the optimal sample KSrPO4:1 mol%Dy^3+,1.3 mol%Li^+, it can be a potential candidate for mercury-free fluorescent lamps. 展开更多
关键词 PHOSPHOR PHOTOLUMINESCENCE VUV Rare earths
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Thermomechanical analysis of triangular zone cracks in vertical continuous casting slabs based on viscoelastic-plastic model
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作者 Juan Cheng Yan-xin Wu +1 位作者 Yang Wang Jian-xun Fu 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2018年第8期813-820,共8页
The triangular zone cracks in 2101 duplex stainless steel produced by the vertical continuous caster have troubled company A for a long time. To simulate the temperature and thermal stress distributions in the solidif... The triangular zone cracks in 2101 duplex stainless steel produced by the vertical continuous caster have troubled company A for a long time. To simulate the temperature and thermal stress distributions in the solidification process of 2101 duplex stainless steel produced by the vertical continuous caster, a two-dimensional viscoelastic-plastic thermomechanically coupled finite element model was established by the secondary development of the commercial nonlinear finite element analysis software MSC Marc. The results show that the thermal stress on the surface reaches a maximum at the exit of the mould, and the highest thermal stresses at the centre of the wide face and the narrow face are 75 and 115 MPa, respectively. Meanwhile, the internal temperature of slab is still higher than the solidus temperature, resulting in no thermal stress. The slab shows different high-temperature strengths and suffers from different stresses at different positions; thus, the risk of cracking also varies. At a location of 6-8 m from the meniscus, the temperature of the triangular zone is 1270-1360℃ and the corresponding permissible high-temperature strength is about 10-30 MPa, while the thermal stress at this time is 60 MPa, which is higher than the high-temperature strength. As a result, triangular zone cracks form easily. 展开更多
关键词 Vertical continuous caster Triangular zone crack Thermomechanical coupling Viscoelastic-plastic model -Finite element analysis
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Particles migration behavior during laser keyhole welding of ZL101/TiB_2 composites
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作者 Haichao CUI Fenggui LU +1 位作者 Xinhua TANG Shun YAO 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2012年第3期190-200,共11页
Particle redistribution occurred with the flow of pool fluid in laser welding aluminum composites. In order to investigate particle migration behavior, a numerical model was established on laser welding of ZL101-TiB2 ... Particle redistribution occurred with the flow of pool fluid in laser welding aluminum composites. In order to investigate particle migration behavior, a numerical model was established on laser welding of ZL101-TiB2 composite. TiB2 migration coupling with fluid was realized. The volume-of-fluid (VOF) method was employed to track free fluid surfaces. The travel heat source was realized utilizing the workpiece mo- tion in place of heat source motion, which made the heat load stable. Melting and evaporation enthalpy, recoil force, surface tension and buoyancy were considered in this model. Through the calculation it showed that the simulated weld cross section shape and particle distribution were in good agreement with experimental results. 展开更多
关键词 Laser welding Numerical simulation Fluid flow Particle migration
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Design and Fabrication of Plasmonic Nanostructures with DNA for Surface-Enhanced Raman Spectroscopy Applications
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作者 Chunbo Leng Cheng Wang +4 位作者 Huixin Xiu Xiangmeng Qu Lizhen Chen Qian Tang Li Li 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2016年第3期273-282,共10页
Plasmonic nanostructures display unique and strongly enhanced optical properties, therefore hold great promise for a wide range of spectroscopic applications, particularly surface-enhanced Raman spectroscopy (SERS).... Plasmonic nanostructures display unique and strongly enhanced optical properties, therefore hold great promise for a wide range of spectroscopic applications, particularly surface-enhanced Raman spectroscopy (SERS). It is well acknowledged that the major contributions to SERS arise from molecules positioned in nanojunctions where the op- tical field is intensively concentrated due to localized surface plasmon excitations. One of the key challenges in SERS therefore lies in the design and fabrication of plasmonic nanostructures with controllable nanojunctions. In recent years, by exploiting the unparalleled base-pairing self-recognition properties, DNA-mediated assembly has emerged as a powerful and programmable tool for the accurate construction of complex and hierarchical plasmonic nanostructures with well-defined geometry and topology. In this review, we will summarize recent advances on de- sign and fabrication of a rich variety of plasmonic nanostructures by virtue of DNA nanotechnology, and discuss their optical properties as well as applications in SERS. 展开更多
关键词 DNA nanotechnology DNA origami surface-enhanced Raman spectroscopy PLASMONICS
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Confined Crystallization Behaviors of Cross-linked Comb-like Copolymers
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作者 Xian-jing Gong 施德安 +4 位作者 Ying-kui Yang Tao Jiang Yan-feng Meng Robert K.Y.Li 蒋世春 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2016年第8期1039-1046,共8页
Cross-linked PEG-based copolymers were obtained via synthesis of polyethylene glycol (PEG) and methoxy polyethylene glycol (MPEG) by the bridging and/or cross-linking agent of 2,4-tolylene diisocyanate (TDI) and... Cross-linked PEG-based copolymers were obtained via synthesis of polyethylene glycol (PEG) and methoxy polyethylene glycol (MPEG) by the bridging and/or cross-linking agent of 2,4-tolylene diisocyanate (TDI) and/or hexamethylene-l,6-diisocyanate homopolymer (HDI trimer). The effects on the crystallization behaviors of the samples could be found with the changes in molecular weight of MC-PEG and molecular weight of SC-PEG in certain cross-linked density. It is revealed that the samples appear not to crystallize when the molecular weight of MC-PEG and SC-PEG are 1000 g/mol or less than that. The samples begin to crystallize when the molecular weight of either MC-PEG or SC-PEG reaches 2000 g/mol. The crystallinity of crystallized MC-PEG decreases with the increasing molecular weight of uncrystallized SC-PEG and the crystallinity of crystallized SC-PEG declines with the rise of molecular weight of uncrystallizable MC-PEG. The chains of SC-PEG (M_n = 2000 g/mol) can fold and align easilier than those of MC-PEG (M_n = 2000 g/mol), when the content of PEG is the same. 展开更多
关键词 PEG-based copolymers Cross-linking Comb-like Confined crystallization behavior.
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Low-temperature sintered(Na_(1/2)Bi_(1/2))TiO_(3)-based incipient piezoceramics for co-fired multilayer actuator application 被引量:4
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作者 Pengyuan Fan Yangyang Zhang +7 位作者 Shan-Tao Zhang Bing Xie Yiwei Zhu Mohsin Ali Marwat Weigang Ma Kai Liu Liang Shu Haibo Zhang 《Journal of Materiomics》 SCIE EI 2019年第3期480-488,共9页
Low-temperature sintered(Na_(1/2)Bi_(1/2))_(0.935)Ba_(0.065)Ti_(0.975)(Fe_(1/2)Nb_(1/2))_(0.025)O_(3)(NBT-BT-0.025FN)lead-free incipient piezoceramics were investigated using high-purity Li_(2)CO_(3) as sintering aids... Low-temperature sintered(Na_(1/2)Bi_(1/2))_(0.935)Ba_(0.065)Ti_(0.975)(Fe_(1/2)Nb_(1/2))_(0.025)O_(3)(NBT-BT-0.025FN)lead-free incipient piezoceramics were investigated using high-purity Li_(2)CO_(3) as sintering aids.With the ≤0.5 wt%Li_(2)CO_(3) addition,the introduced Li^(+) cations precede to enter the A-sites of the perovskite lattice to compensate for the A-site deficiencies.Once the addition exceeds 0.5 wt%,the excess Lit cations will occupy B-sites and give rise to the generation of oxygen vacancies,which accelerate the mass transport and thus lower the sintering temperature effectively from 1100℃ down to 925℃.It was also found that a small amount of Lit addition has little effect on the phase structure and electromechanical properties of the system,but overweight seriously disturbs these characteristics because of the large lattice distortion.The sintered NBT-BT-0.025FN incipient piezoceramics with 1.25 wt%Li_(2)CO_(3) addition at 925℃ provides a large strain of 0.33% and a corresponding large signal piezoelectric coefficient d_(33)^(*) of 550 pm/V at 60 kV/cm,indicating this system is a very promising candidate for lead-free co-fired multilayer actuator application. 展开更多
关键词 Lead-free piezoceramics (Na_(1/2)Bi_(1/2))TiO_(3) Low-temperature sintering Electric-field-induced strain
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