检索结果-南通市图书馆

Fabrication, Structure and Optical Properties of Zr4+ Doped Ba（Mg, Ta） O3 Transparent Ceramics with High Refractive Index

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2019年第6期38卷 941-946页

作者： WEN Zi-Cheng MA Chao-Yang ZHAO Chong CAO Yong-Ge Department of Physics Renmin University of ChinaBeijing 100872China Beijing key laboratory of Opto-electronic Functional materials&Micro-nano Devices Beijing Municipal Science and Technology CommissionBeijing 100872China

Novel transparent ceramics of Zr4+ doped Ba(Mg,Ta)O3(BMT)with a high refractive index of 2.037 at 587.56 nm were successfully fabricated via high temperature solid-state-reaction sintering *** make it transparent,the pure cubic Ba(Zr,Mg,Ta)O3 phases(BZMT)were realized in advance by skillfully modulating the lattice structure of BMT from trigonal symmetric to cubic symmetric through doping Zr4+ into the lattice of BMT *** optical transmittance of 74% at 650 n,,which hit the upper limit of the theory,was achieved for *** abbe number of 23.4 and the bandgap Eg of 3.22 eV have been calculated.

关键词： BZMT transparent ceramics refractive index optical materials mechanical properties

The Dominant Glutamic Acid Metabolic Flux to Produce γ-Amino Butyric Acid over Proline in Nicotiana tabacum Leaves under Water Stress Relates to its Significant Role in Antioxidant Activity

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2011年第8期53卷 608-618页

作者： Cuili Liu Li Zhao Guanghui Yu key laboratory for Biotechnology of the State Ethnic affairs commission College of Life Sciences South-Central University for Nationalities Wuhan 430074 China

γ-Amino butyric acid （GABA） and proline play a crucial role in protecting plants during various environmental stresses. Their synthesis is from the common precursor glutamic acid, which is catalyzed by glutamate decarboxylase and △1-pyrroline-5-carboxylate synthetase respectively. However, the dominant pathway under water stress has not yet been established. To explore this, excised tobacco leaves were used to simulate a water-stress condition. The results showed GABA content was much higher than that of proline in leaves under water-deficit and non-water-deficit conditions. Specifically, the amount of GABA significantly increased compared to proline under continuous water loss for 16 h, indicating that GABA biosynthesis is the dominant pathway from glutamic acid metabolism under these conditions. Quantitative reverse transcription polymerase chain reaction and protein Western gel-blot analysis further confirmed this. To explore the function of GABA accumulation, a system producing superoxide anion （O 2 - ）, peroxide hydrogen （H 2 O 2 ）, and singlet oxygen （ 1 O 2 ） was employed to investigate the scavenging role on free-radical production. The results demonstrated that the scavenging ability of GABA for O 2 - , H 2 O 2 , and 1 O 2 was significantly higher than that of proline. This indicated that GABA acts as an effective osmolyte to reduce the production of reactive oxygen species under water stress.

关键词： glutamic acid proline reactive oxygen species water stress γ-amino butyric acid.

Efficient visible light photo-Fenton-like degradation of organic pollutants using in situ surface-modified BiFeO_3 as a catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第6期25卷 1213-1225页

作者： Junjian An Lihua Zhu Yingying Zhang Heqing Tang College of Chemistry and Chemical Engineering Huazhong University of Science and Technology key laboratory of Catalysis and materials Science of the State Ethnic affairs commission and Ministry of Education College of Chemistry and Materials ScienceSouth-Central University for Nationalities

The visible light photo-Fenton-like catalytic performance of BiFeO3 nanoparticles was investigated using Methyl Violet （MV）, Rhodamine B （RhB） and phenol as probes. Under optimum conditions, the pseudo first-order rate constant （k） was determined to be 2.21 × 10^-2, 5.56 × 10^-2 and 2.01 × 10^-2 min〈 for the degradation of MV （30 μmol/L）, RhB （10 μmol/L） and phenol （3 mmol/L）, respectively, in the BiFeO3-H202-visible light （Vis） system. The introduction of visible light irradiation increased the k values of MV, RhB and phenol degradation 3.47, 1.95 and 2.07 times in comparison with those in dark. Generally, the k values in the BiFeO3- H202-Vis system were accelerated by increasing BiFeO3 load and H202 concentration, but decreased with increasing initial pollutant concentration. To further enhance the degradation of pollutants at high concentrations, BiFeO3 was modified with the addition of surface modifiers. The addition of ethylenediamineteraacetic acid （EDTA, 0.4 mmol/L） increased the k value of MV degradation （60 μmol/L） from 1.01 × 10.2 min^-1 in the BiFeO3-H202-Vis system to 1.30 min^-1 in the EDTA-BiFeO3-H2O2-Vis system by a factor of 128. This suggests that in situ surface modification can enable BiFeO3 nano-particles to be a promising visible light photo-Fenton-like catalyst for the degradation of organic pollutants.

关键词： nanoscale BiFeO3 visible light photo-Fenton-like catalysis degradation surface modification

EDA-assisted synthesis of multifunctional snowflake-Cu_(2)S/CdZnS S-scheme heterojunction for improved the photocatalytic hydrogen evolution

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2022年第26期121卷 28-39页

作者： Guorong Wang Yongkang Quan Kaicheng Yang Zhiliang Jin School of Chemistry and Chemical Engineering Ningxia Key Laboratory of Solar Chemical Conversion TechnologyKey Laboratory for Chemical Engineering and TechnologyState Ethnic Affairs CommissionNorth Minzu UniversityYinchuan 750021China

The charge separation efficiency is one of the main factors affecting the solar photocatalytic decomposition of water to produce *** a unique heterojunction can accelerate the separation and transfer of photo-generated charges,and effectively improve the photocatalytic efficiency,which is considered a potential ***,the 2%Cu_(2)S/CZS step-scheme(S-scheme)heterojunction based on morphology and electronic structure was successfully prepared via simple hydrothermal *** with the monomer Cu_(2)S and Cd Zn S,the hydrogen evolution rate of 2%Cu_(2)S/CZS samples is significantly *** particular,the 2%Cu_(2)S/CZS not only shows high hydrogen evolution rate of 5904μmol g^(-1)h^(-1)(3.19 times than original Cd Zn S),but also presents preferable cyclic *** to the characterization,we believe that the introduction of Cu_(2)S has the following three advantages:(i)The snowflake structure of Cu_(2)S reduces the agglomeration of granular Cd Zn S.(ii)The Cu_(2)S with narrow band gap broadens the light response range of the composite catalyst.(iii)The Cu_(2)S was introduced into Cd Zn S to form S-scheme heterojunction,which accelerated the separation and transfer of photo-generated *** work broadens the idea of designing efficient photocatalyst of hydrogen evolution.

关键词： S-scheme Heterojunction Multifunctional Snowflake-Cu_(2)S Photocatalyst

Greatly increased visible-light photocatalytic activity of SnS_(2)/carbon nanotube composite for Cr(VI)reduction:Insights into effects of solid acid structure

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2023年第30期161卷 233-244页

作者： Zhen Wan Qihang Mao Jingjing Xiang Dongge Ma Heqing Tang key laboratory of Catalysis and materials Science of the State Ethnic affairs commission and Ministry of Education College of Resources and Environmental ScienceSouth-Central Minzu UniversityWuhan 430074China Department of Chemistry College of Chemistry and Materials EngineeringBeijing Technology and Business UniversityBeijing 100048China

A composite of SnS_(2)and carbon nanotube(CNT)was successfully synthesized as a visible-light-driven photocatalyst with a mechanochemical *** comparing with SnS_(2),the SnS_(2)/CNT composite im-proved much the photocatalytic removal of Cr(VI)in acidic condition,which was confirmed to its special solid acid *** the synthesis of the SnS_(2)/CNT composite by ball milling,S-C p-πbonding was formed between sulfur atoms in SnS_(2)and carbon atoms in *** generated S-C p-πbonding enhanced the transfer of photo-induced electrons in the bulk phase of the composite photocatalyst un-der visible light ***,the persistent radical sites on CNT were able to trap photo-induced electrons and served as conjugated acid sites in the photocatalysis,which increased surface concentration of protons through their association with H+.These made the catalyst have a solid acid structure with plentiful surface protons,promoting the interfacial electron transfer between the catalysts and Cr(VI)and increasing the source of H+for the reduction of Cr(VI).As a result,the photocatalytic reduction rate of Cr(VI)on the SnS_(2)/CNT composite were dramatically enhanced,being about 800%that on SnS_(2).On the basis of various characterizations and probe experiments,we confirmed the significance of the solid acid structure of the photocatalyst and clarified the catalytic mechanism of the new *** finding may provide a new strategy to prepare highly active photocatalysts for proton-involved reactions.

关键词： SnS_(2)/CNT composite S-C p-πbonding Solid acid Ball milling Cr(VI)reduction

Selective enhancement of green upconversion luminescence of Er-Yb:NaYF4 by surface plasmon resonance of W18O49 nanoflowers and applications in temperature sensing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第9期27卷 151-156页

作者： Ang Li Jin-Lei Wu Xue-Song Xu Yang Liu Ya-Nan Bao Bin Dong School of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 China Department of Physics Dalian Maritime University Dalian 116026 China key laboratory of Photosensitive materials and Device of Liaoning Province Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission School of Physics and Materials Engineering Dalian Minzu University Dalian 116600 China

The W（18）O（49） nanoflowers with a diameter of 500 nm are prepared by a facile hydrothermal method. The Er-Yb：NaYF4 nanoparticles are adsorbed on the petals（the position of the strongest local electric field on W（18）O（49） nanoflowers）.With a 976 nm laser diode（LD） as an excitation source, the selectively green upconversion luminescence（UCL） is observed to be enhanced by two orders of magnitude in Er-Yb： NaYF4/W（18）O（49） nanoflowers heterostructures. It suggests that the near infrared（NIR）-excited localized surface plasmon resonance（LSPR） of W（18）O（49） is primarily responsible for the enhanced UCL, which could be partly reabsorbed by the W（18）O（49）, thus leading to the selective enhancement of green UCL for the Er-Yb： NaYF4. The fluorescence intensity ratio is investigated as a function of temperature based on the intense green UCL, which indicates that Er-Yb： NaYF4/W（18）O（49） nanoflower heterostructures have good potential for developing into temperature sensors.

关键词： upconversion localized surface plasmon resonance Er-Yb: NaYF4/W18O49 temperature sensing

Effective Methods and Performance Analysis on Data Transmission Security with Blind Source Separation in Space-Based AIS

在线全文

学校读者我要写书评

暂无评论

china Communications 2022年第4期19卷 154-165页

作者： Chengjie Li Lidong Zhu Zhongqiang Luo Zhen Zhang Ying Yang The key laboratory for Computer Systems of State Ethnic affairs commission School of Computer Science and Technology(Southwest Minzu University)Chengdu 610000China national key laboratory of Science and Technology on Communications(University of electronic Science and Technology of china) Chengdu 610000China Sichuan University of Science&Engineering ZigongChina College of Computer Science(Sichuan University) Chengdu 610000China

In space-based Automatic Identification Systems(AIS), due to high satellite orbits, several Ad Hoc cells within the observation range of the satellite are vulnerable to interference by an external *** increase efficiency in target detection and improve system security, a blind source separation method is adopted for processing the conflicting signals received by satellites. Compared to traditional methods, we formulate the separation problem as a clustering problem. Since our algorithm is affected by the sparseness of source signals, to get satisfactory results, our algorithm assumes that the distance between two arbitrary mixed-signal vectors is less than the doubled sum of variances of distribution of the corresponding mixtures. Signal sparsity is overcome by computing the Short-Time Fourier Transform, and the mixed source signals are separated using the improved PSO clustering. We evaluated the performance and the robustness of the proposed network architecture by several simulations. The experimental results demonstrate the effectiveness of the proposed method in not only improving satellite signal receiving ability but also in enhancing space-based AIS security.

关键词： space-based automatic identification systems tolerance rough set particle swarm optimization invulnerability performance

Preparation of Bi_(2)O_(3)/BiOI Step-scheme Heterojunction Photocatalysts and Their Degradation Mechanism of Methylene Blue

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(materials Science) 2022年第5期37卷 801-806页

作者： JIANG Xuechao TAN Haiyan SHI Xinyu CHENG Xinhua HU Weibing HU Xinhui key laboratory of Green Manufacturing of Super-light Elastomer materials of State Ethnic affairs commission School of Chemistry and Environmental EngineeringHubei Minzu UniversityEnshi445000China Guangxi key laboratory of Chemistry and Engineering of Forest Products Guangxi University for NationalitiesNanning530006China State key laboratory of Advanced Technology for materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China

Bi_(2)O_(3)/BiOI step-scheme(S-scheme) heterojunction photocatalyst was synthesized by green calcination method, its degradation ability of methylene blue was investigated, and the photocatalytic performance of the Bi_(2)O_(3)/BiOI heterojunction, Bi_(2)O_(3) and BiOI was compared. The structure and morphology of the samples were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and UV-vis diffuse reflection spectrum (UV-vis DRS). The degradation rate of methylene blue was analysised by spectrophotometry, and the calculation result showed that the degradation rate of methylene blue was 97.8% in 150 minutes. The first order kinetic rate constant of 10%Bi_(2)O_(3)/BiOI is 0.021 8 min^(-1), which are2.37 and 2.68 times of BiOI(0.009 18 min^(-1)) and Bi_(2)O_(3) (0.008 03 min^(-1)) respectively. The calculation result shows that the work function of Bi_(2)O_(3) and BiOI are 3.0 e V and 6.0 e V, respectively, by density functional theory(DFT). When this S-scheme heterojunction is used as a photocatalyst, the weaker electrons in the conduction band of BiOI will be combined with the weaker holes in the Bi_(2)O_(3) valence band under combined effect with built-in electric field and band bending, which will retain stronger photoelectrons and holes between Bi_(2)O_(3) and BiOI. This may be the internal reason for the efficient degradation of tetracycline by Bi_(2)O_(3)/BiOI S-scheme heterostructures.

关键词： step-scheme heterojunction methylene blue antibiotic wastewater treatment photocatalytic degradation charge separation

Enhanced antibiotic degradation performance of Cd_(0.5)Zn_(0.5)S/Bi_(2)MoO_(6) S-scheme photocatalyst by carbon dot modification

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2023年第33期164卷 59-67页

作者： Shijie Li Ruyu Yan Mingjie Cai Wei Jiang Mingyi Zhang Xin Li key laboratory of Health Risk Factors for Seafood of Zhejiang Province National Engineering Research Center for Marine AquacultureCollege of Marine Science and TechnologyZhejiang Ocean UniversityZhoushan 316022China key laboratory for Photonic and electronic Bandgap materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal UniversityHarbin 150025China Institute of Biomass Engineering Key Laboratory of Energy Plants Resource and UtilizationMinistry of Agriculture and Rural AffairsSouth China Agricultural UniversityGuangzhou 510642China

S-scheme heterojunction engineering is an effective strategy to attain distinctive ***,a carbon dots modulated S-scheme hetero-structured photocatalyst of Cd_(0.5)Zn_(0.5)S nanoparticles/Bi_(2)MoO_(6) microspheres/carbon dots (CZCBM),aiming to conquer the photo-corrosion and strengthen the photocatalytic property of Cd_(0.5)Zn_(0.5)S,was developed via a facile solvothermal *** visible light,the optimal CZCBM-2 affords a 1.8-,1.5-,or 0.6-time reinforcement in the oxytetracycline degradation rate constant compared to Bi_(2)MoO_(6),Cd_(0.5)Zn_(0.5)S or Cd_(0.5)Zn_(0.5)S/Bi_(2)MoO_(6),which is credited to the strengthened visible-light response,increased reactive sites,and efficient dissolution of photo-carriers with optimal redox capacity because of the co-effect of carbon dots and S-scheme ***,the photo-corrosion of Cd_(0.5)Zn_(0.5)S is significantly suppressed and CZCBM-2 affords superior stability and reusability during cycling ***,CZCBM-2 can be well adapted to various *** toxicology appraisement unravels the decreased eco-toxicity of most intermediates compared to ***,an S-scheme charge transfer mechanism with carbon dots as electron reservoir in CZCBM is deduced,which uncloses that •O_(2)− and h+ dominantly account for oxytetracycline eradication and *** study demonstrates the design of unique carbon dots favored S-scheme heterostructures as an effective “Two Birds with One Stone” strategy to achieve high anti-photo-corrosion performance and reinforced photocatalytic performance of sulfides.

关键词： Carbon dots S-scheme heterojunction Synergistic effect Pharmaceuticals and personal care products(PPCPs) Toxicity analysis Anti-photocorrosion