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International Journal of Minerals,Metallurgy and Materials 2013年第3期20卷 279-283页

作者： Lei Zhao bo-ping zhang Min Cui Yan Li School of Materials Science and Engineering University of Science and Technology Beijing

（1 - x）PbZr0.54Tio.4603-xKNbo3 （0 〈 x 〈 25mo1%）（abbreviated as PZT-xKN） piezoelectric ceramics were successfully fabricated by a traditional sintering technique at 1225℃ for 30 min. The influence of KNbo3 content on the crystal structure and electrical properties of the PZT-xKN piezoelectric ceramics was studied. Samples with 0 〈 x 0.20 show a pure peroskite structure, indicating that ul KNbodiffused ito the crystal lattice of PZT to form a single solid solution in this compositional range. A second Pb3Nb4013 phase is observed in the PZT-0.25KN sample, showing that the maximum solid solubility of KNbo3 in PZT matrix ceramic is less than 25mo1%. Compared with pure PZT piezoelectric ceramics, samples containing KNbo3 have smaller crystal grains. PZT-0.15KN exhibits excellent piezoelectric properties with d33 ： 209 pC/N.

关键词： piezoelectric ceramics crystal structure electrical properties grains

Influence of sintering temperature on the structure and piezoelectric properties of ZnO-modified (Li, Na, K)Nbo_(3) lead-free ceramics

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 843-848页

作者： Hai-tao Li bo-ping zhang Wei-gang Yang Nan Ma School of Materials Science and Engineering He'nan University of Science and Technology Luoyang 471003 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

ZnO-modified (Li, Na, K)Nbo3 lead-free ceramics with a nominal composition of Li0.06(Na0.535K0.48)0.94Nbo3+0.7mol% ZnO (LNKN-ZT) was synthesized normally at 930-1000℃. The Zn ions incorporated into the A-site at a higher sintering temperaVare, which changed LNKN-Z7 to soft piezoelectric ceramics with the mechanical quality factor decreasing from 228 to 192. A phase transition from tetragonal to orthorhombic symmetry was identified by XRD analysis, and the corresponding calculation of lattice parameters was conducted at 970-980℃. Because of such transitional behavior and fine microstructure, the optimized values of piezoelectric coefficient, planar electromechanical coupling coefficient, and relative dielectric constant were obtained.

关键词： piezocemmics niobates zinc oxide modification phase transitions piezoelectricity sintering

Microstructure,crystalline phase and electrical properties of Li_(0.06)(Na_(0.5)K_(0.5))_(0.94)Nb_(1-2x/5)Mg_xO_3 lead-free piezoelectric ceramics

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 340-346页

作者： Hai-tao Li bo-ping zhang Qian zhang Peng-peng Shang Gao-lei Zhao School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Henan University of Science and Technology Luoyang 471003 China

MgO-modified Li0.06（Na0.5K0.5）0.94Nbo3O3 （L6NKN） lead-free piezoelectric ceramics were synthesized by normal sintering at a rela- tively low temperature of 1000℃. The crystalline phase, microstructure, and electrical properties of the ceramics were investigated with a special emphasis on the influence of MgO content. The addition of MgO effectively improves the sintembility of the L6NKN ceramics. X-my diffr cfion analysis indicates that the morphotropic phase boundary （MPB） separating orthorhombic and tetragonal phases for the ceramics lies in the range of Mg doping content （x） from 0.3at% to 0.7at%. High electrical properties of the piezoelectric constant （d33=238 pC/N）, planar electromechanical coupling coefficient （kp=41.5%）, relative dielectric constant （εr=905）, and remanent polarization （Pr=38.3 μC/cm2） are obtained from the specimen with x=0.5at%, which suggests that the Li0.06（Na0.5K0.5）0.94Nb（1-2x/5）MgxO3 （x=0.5at%） ceramic is a promising lead-free piezoelectric material.

关键词： lead-flee piezoelectric ceramics sinterability sintering morphotropic phase boundary

Optimal performance of Cu_(1.8)S_(1-x)Te_(x) thermoelectric materials fabricated via high-pressure process at room temperature

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Journal of Advanced Ceramics 2020年第5期9卷 535-543页

作者： Rui zhang Jun PEI Zhi-Jia HAN Yin WU Zhao ZHAO bo-ping zhang Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Cu_(1.8)S has been considered as a potential thermoelectric(TE)material for its stable electrical and thermal properties,environmental benignity,and low ***,the TE properties of nanostructured Cu_(1.8)S_(1-x)Te_(x)(0≤x≤0.2)bulks fabricated by a facile process combining mechanical alloying(MA)and room-temperature high-pressure sintering(RT-HPS)technique were optimized via eliminating the volatilization of S element and suppressing grain ***,a single phase of Cu_(1.8)S was obtained at x=0,and a second Cu_(1.96)S phase formed in all Cu_(1.8)S_(1-x)Te_(x) samples when 0.05≤x≤*** further increasing x to 0.15≤x≤0.2,the Cu_(2-z)Te phase was detected and the samples consisted of Cu_(1.8)S,Cu_(1.96)S,and Cu_(2-z)Te *** from a modified band structure and the coexisted phases of Cu_(1.96)S and Cu_(2-z)Te,the power factor is enhanced in all Cu_(1.8)S_(1-x)Te_(x)(0.05≤x≤0.2)*** with a drastic decrease in the thermal conductivity due to the strengthened phonon scatterings from multiscale defects introduced by Te doping and nano-grain boundaries,a maximum figure of merit(ZT)of 0.352 is reached at 623 K for Cu_(1.8)S_(0.875)Te_(0.125),which is 171%higher than that of Cu_(1.8)S(0.130).The study demonstrates that doping Te is an effective strategy to improve the TE performance of Cu_(1.8)S based materials and the proposed facile method combing MA and RT-HPS is a potential way to fabricate nanostructured bulks.

关键词： Cu_(1.8)S Te doping nanostructure high pressure thermoelectric(TE)

Enhanced photocatalytic activity in Ag-nanoparticle-dispersed BaTiO3 composite thin films: Role of charge transfer

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Journal of Advanced Ceramics 2017年第1期6卷 1-10页

作者： Suwei zhang bo-ping zhang Shun LI Zhicheng HUANG Chushu YANG Huiying WANG Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Optical absorption and photocatalytic activity can be enhanced by surface plasmon resonance (SPR) effect,but the charge transfer (CT) mechanism between the dispersed noble metal nanoparticles (NPs) and the semiconductor matrix has been ***,we adduce a direct and strong evidence in Ag-nanoparticle-dispersed BaTiO3 (Ag/BTO) composite films through X-ray photoelectron and photoluminescence spectra which reveals the CT from BTO trapped by Ag NPs under UV light and from Ag NPs to BTO under visible *** to the broadened optical absorption and efficient CT from Ag NPs to BTO,the Ag25/BTO film manifests the optimal photocatalytic activity under the irradiation of visible light rather than UV-Vis *** work provides a helpful insight to design highly efficient plasmonic photocatalyst through considering the synergetic effect of the CT between metal and semiconductor on the enhanced photocatalytic activity.

关键词： charge transfer (CT) composite films photocatalytic activity surface plasmon resonance (SPR)

High-performance BiFeO_(3)eBaTiO_(3)lead-free piezoceramics insensitive to off-stoichiometry and processing temperature

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Journal of Materiomics 2023年第2期9卷 353-361页

作者： Yu-Cheng Tang Yang Yin Ai-Zhen Song He-zhang Li bo-ping zhang School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China National Institute for Materials Science(NIMS)1-2-1 Sengen TsukubaIbaraki305-0047Japan

It is well-known that the performance of BiFeO3eBaTiO3(BF-BT)ceramics is sensitive to composition,calcining and sintering temperature(Tcal and Tsint)due to the formation of Bi25FeO39 and/or Bi2Fe4O9 impurities and/or the volatilization of Bi_(2)O_(3).We report remarkably stable electrical properties over the range of0.03≤x≤0.05 and 930℃≤Tsint≤970C in 0.7Bi(1þx)FeO_(3)-0.3BaTiO_(3)ceramics prepared by one-step *** method avoids the thermodynamically unstable region of BiFeO_(3)and prevents the formation of Bi25FeO39 and/or Bi_(2)Fe_(4)O_(9)impurities even when the addition of a-Bi_(2)O_(3)raw material is intentionally deficient or rich to make off-stoichiometric BF-BT,thus greatly improving the robustness of compositional and ***-pseudocubic phase coexists in all ceramics,and their CR/CPC fraction are 48.0/52.0e50.6/49.4 and 55.9/44.1e56.6/43.4 when x increases from0.05≤x≤0 to 0.01≤x≤*** stable electrical properties of d33¼180e205 pC/N,Pr¼17.9e23.8 mC/cm^(2),and TC¼485e518℃are *** maximum d_(33T)/d_(33RT)of BF-BT is twice that of soft PZT,superior to most the-state-of-art lead-free *** results provide a synthesis strategy for designing high performance piezoelectric materials with good stability and easy industrialization.

关键词： BiFeO_(3)-BaTiO_(3) Lead-free ceramics One-step process Electrical properties Thermal stability

Genotypic differences in callus induction and plant regeneration from mature embryos of barley(Hordeum vulgare L.)

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第5期12卷 399-407页

作者： Yong HAN Xiao-li JIN Fei-bo WU Guo-ping zhang Department of Agronomy College of Agriculture and Biotechnology Zhejiang University Hangzhou 310029 China

An efficient induction system and regeneration protocol based on mature barley embryos were *** isolated from mature seeds,dehusked by hand and inoculated with longitudinally bisected sections,showed low contamination and high primary callus-forming *** influences of nine culture media on primary callus induction and germination from the mature embryos of barley cultivars Golden Promise and Zaoshu 3 were *** results showed that the two cultivars had much higher values of primary callus induction in the B16M6D medium as compared to the other eight medium formulations,with a frequency of 74.3% and 78.4% for Golden Promise and Zaoshu 3,***,Zaoshu 3 demonstrated particularly high stability in callus induction over the different media,indicating its potential utilization in callus induction and regeneration for its good agronomic traits and wide *** were significant differences amongst 11 barley genotypes in terms of primary callus induction in the optimum medium,with percentages of callus induction and germination response ranging from 17.9% to 78.4% and 2.8% to 47.4%,*** plantlets of Dong 17,Golden Promise,and Zaoshu 3 were successfully de-veloped from primary calli through embryogenesis,with green plant differentiation frequencies ranging from 9.7% to 21.0% across genotypes.

关键词： Barley Mature embryo Genotypic difference Primary callus Plant regeneration

The Research on Handoff Strategy in Beyond 3G Wireless Networks

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The Journal of China Universities of Posts and Telecommunications 2006年第2期13卷 26-30页

作者： CUI Hong-yan TIAN Hui XU Hai-bo zhang ping College of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

One of the major challenges for beyond third generation mobile .systems is efficient mobility management. This paper proposes a distributed dynamic management .scheme of handoff based on B3G networks. This scheme can reduce the cost of update signalling and transmitting packets, and improve the system capability. In this scheme, the dynamic building network approach is adopted to deduce the update signalling cost. We implement the distributed dynamic management scheme of handoff in a simulation platform and compare its performance with that of general centralized handoff management schemes. Our simulation results indicate that our scheme is capable of reducing the update handoff latency, and enhancing the performance.

关键词： B3G IPv6 handoff AP CA

BiAlO_(3)-modified BiFeO_(3)-BaTiO_(3) high Curie temperature lead-free piezoelectric ceramics with enhanced performance

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Rare Metals 2023年第11期42卷 3839-3850页

作者： Xiao-Xiao Zhou Yu-Cheng Tang He-zhang Li Yi-Jin Hao Meng-ping Xue Jun Pei Xiao-Yan Peng bo-ping zhang School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Department of Precision Instrument Tsinghua UniversityBeijing10084China Beijing Key Laboratory of Special Ceramics and Refractories China Iron&Steel Research Institute GroupBeijing100081China

BiFeO_(3)-BaTiO_(3)(BF-BT)lead-free piezoelectric ceramics have high piezoelectricity and high Curie temperature(T_(C)),but the mixed-valence Fe ions and Bi^(3+)volatilization would promote the formation of Bi_(25)FeO_(40)/Bi_(2)Fe_(4)O_9 and oxygen vacancy,which greatly degrade the insulation properties required for *** this study,it was found that the modification of BiAlO_(3)(BA)in BF-BT ceramics could effectively solve these problems,reducing the leakage current to 1×10^(-9)A·cm^(-2)and transiting the space charge-limited conduction to ohmic *** of the enhanced insulation properties and appropriate rhombohedral-pseudocubic phase ratio(C_R/C_(PC)),BF-BT-xBA ceramics in an optimized composition obtain enhanced piezoelectric performance:piezoelectric charge coefficient(d_(33))=196 pC·N^(-1),planar electromechanical coupling coefficient(k_(p))=31.1%,T_(C)=487℃and depolarization temperature(T_d)=250°C;unipolar strain(S_(uni))=0.17%and piezoelectric strain coefficient(d_(33)^(*))=335 pm·V^(-1)at 100℃.Especially,d_(33)exceeds 283 pC·N^(-1)at 233℃and d_(33)^(*)is 335 pm·V^(-1)at100℃,showing an excellent high-temperature piezoelectricity and high depolarization *** results are attributed to the domain structure of rhombohedral-pseudocubic phase coexistence and its high-temperature switching *** work provides a feasible and effective approach to improve the high temperature piezoelectric properties of BF-BT-xBA ceramics,making them more suitable for high temperature applications.

关键词： BiFeO_(3)-BaTiO_(3)(BF-BT) Curie temperature Electrical insulation properties Piezoelectric properties Thermal stability

Microstructure and optical absorption properties of Au/NiO thin films

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 115-120页

作者： Cui-hua Zhao bo-ping zhang Shi-jing Wang Peng-peng Shang Can Chen School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China College of Materials Science and Engineering Guangxi University Nanning 530004 China

Au nanoparticles dispersed NiO composite films were prepared by a chemical solution *** phase structure,microstructure,surface chemical state,and optical absorption properties of the films were characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,and Uv-vis *** results indicate that Au particles with the average diameters of 35-42 nm are approximately spherical and disperse in the NiO *** optical absorption peaks due to the surface plasmon resonance of Au particles shift to the shorter wavelength and intensify with the increase of Au *** bandwidth narrows when the Au content increases from 8.4wt% to 45.2wt%,but widens by further increasing the Au content from 45.2wt% to 60.5wt%.The band gap Eg increases with the increase of Au contents from 8.4wt% to 45.2wt%,but decreases by further increasing the Au content.

关键词： thin films nanostructured materials solutions synthesis X-ray diffraction analysis optical properties microstructure