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Development of aqueous-phase CdSeS magic-size clusters at room temperature and quantum dots at elevated temperatures

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Nano Research 2024年第12期17卷 10529-10535页

作者： Yao Jiang Zhe Wang Shasha Wang Chunchun Zhang Chaoran Luan Xiaoqin Chen Kui Yu Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China Engineering Research Center in Biomaterials Sichuan UniversityChengdu 610065China Analytical&Testing Center Sichuan UniversityChengdu 610065China College of Biomedical Engineering Sichuan UniversityChengdu 610065China

Little is known about the synthesis of colloidal ternary semiconductor magic-size clusters(MSCs)and quantum dots(QDs)in an aqueous *** report here the first synthesis of aqueous-phase CdSeS MSC-380(displaying sharp optical absorption peaking at~380 nm)at room temperature and QDs at elevated *** reaction contains CdCl2·2.5H_(2)O,3-mercaptopropionic acid(MPA,HS-(CH_(2))2-COOH),selenourea(SeU,NH_(2)-C(Se)-NH_(2)),and thioacetamide(TAA,CH3-C(S)-NH_(2)).Prior to the nucleation and growth(N/G)of QDs,there are clusters formed at 25℃.The prenucleation-stage clusters are the precursor compound of CdSeS MSC-380(PC-380).The PC is relatively transparent in optical absorption;in the presence of a primary amine butylamine(BTA,CH3-(CH_(2))3-NH_(2)),the PC transforms to absorbing CdSeS *** 80℃,the PC decreases and the N/G of CdSeS QDs *** present study paves the way to the aqueous-phase synthesis of ternary CdSeS MSCs and QDs,providing an in-depth understanding of the cluster formation in the prenucleation stage of CdSeS QDs.

关键词： aqueous phase precursor compound(PC) magic-size cluster(MSC) quantum dot(QD) cadmium selenide sulfide

Average Distribution of Ionic Charges and Ionizability for the Au Plasma System

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Chinese Physics Letters 2002年第7期19卷 934-936页

作者：杨天丽蒋刚等 InstituteofAtomicandMolecularPhysics SichuanUniversityChengdu610065

Using relativistic multi-configuration Dirac-Fock theory, we calculate the transition data of 3dj-nfj' (n = 5,6,7) for the M-shell from an Ni-like Au ion to an As-like Au ion using the GRASP programme with the core-polarization, quantum electrodynamical effect and Breit correction. Based on the present calculation results and the experiment of the Xingguang-II laser facilities, the average distribution of ionic charge and the ionizability have been derived. The average ionization degree of Au plasma Z* is 49.06±0.5, which is comparable with the result of the Lawrence Livermore National Laboratory.

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RESEARCH ON SYSTEM DYNAMICS MODEL OF CONVEYANCE CAPACITY IN SYMMETRIC COMPOUND CHANNELS

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Journal of Hydrodynamics 2005年第3期17卷 295-300页

作者： YANGKe-jun CAOShu-you LIUXing-nian StateKeyLaboratoryofHydraulicsonHighSpeedFlows SichuanUniversityChengdu610065China

Stage-discharge curves are particularly important in river basin management. For a compound channel, the stage-discharge curve is often difficult to be extrapolated to yield estimates of level for a given frequency of flow. By analyzing a large number of experimental data from Science and Engineering Research Council Flood Channel Facility (SERC-FCF) and applying system dynamics method, the authors established system dynamics model of conveyance capacity when rivers flow in an overbank mode, spilling onto the adjoining flood plain. The model was applied to a compound channel. And the corresponding simulated results are shown to attain high accurcy.

关键词： system dynamics model conveyance capacity symmetric compound channels resistance coefficient

Precursor compound enabled formation of aqueous-phase CdSe magic-size clusters at room temperature

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Nano Research 2022年第3期15卷 2634-2642页

作者： Min Zhao Qingyuan Chen Yongcheng Zhu Yuehui Liu Chunchun Zhang Gang Jiang Meng Zhang Kui Yu School of Chemical Engineering Sichuan UniversityChengdu 610065China Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China Engineering Research Center in Biomaterials Sichuan UniversityChengdu 610065China Analytical&Testing Center Sichuan UniversityChengdu 610065China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065China

The formation pathway of aqueous-phase colloidal semiconductor magic-size clusters(MSCs)remains *** the present work,we demonstrate,for the first time,a precursor compound(PC)-enabled formation pathway of aqueous-phase CdSe MSCs exhibiting a sharp absorption peaking at about 420 nm(MSC-420).The CdSe MSC-420 is synthesized with CdCl2 and selenourea as the respective Cd and Se sources,and with 3-mercaptopropionic acid or L-cysteine as a *** featureless CdSe PCs form first in the aqueous reaction batches,which transform to MSC-420 in the presence of primary *** coordination between primary amine and Cd^(2+)on PCs may be responsible to the PC-to-MSC *** increasing the reactant concentrations or decreasing the CdCl_(2)-ligand feed molar ratios,the Cd precursor self-assembles into large aggregates,which may encapsulate the resulting CdSe PCs and inhibit their transformation to *** present study sheds essential light on the syntheses and formation mechanisms of nanocrystals.

关键词： aqueous magic-size cluster precursor compound formation pathway self-assembly precursor configuration

One-pot synthesis of SrTiO_(3)-SrCO_(3) heterojunction with strong interfacial electronic interaction as a novel photocatalyst for water splitting to generate H_(2)

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Chinese Chemical Letters 2023年第2期34卷 224-229页

作者： Yige Deng Song Shu Ningjie Fang Ruobing Wang Yinghao Chu Zhaobing Liu Wanglai Cen College of Architecture and Environment Sichuan UniversityChengdu 610065China chengdu Environment Group Chengdu 610065China Institute of New Energy and Low Carbon Technology Sichuan UniversityChengdu 610065China

Photocatalytic hydrogen evolution from water splitting is a promising strategy for realizing the vision of carbon ***,a novel SrTi O_(3)-SrCO_(3)n-n heterojunction was used for the first time for water splitting to generate H_(2).The heterojunction was synthesized by a soft chemical one-pot hydrothermal *** Sr TiO_(3)-SrCO_(3)loading with 3 wt%Pt shows the maximum photocatalytic H_(2)evolution rate of3.62 mmol h^(-1)g^(-1)under simulated sunlight irradiation,which is 20.1 times higher than that of pristine SrTiO_(3).The apparent quantum efficiency of Sr TiO_(3)-SrCO_(3)reaches 21.73%at 313 nm,and it shows good stability during cyclic *** formation of compact Sr TiO_(3)-SrCO_(3)heterojunction with strong interfacial electronic interaction promotes the transmission and separation of photo-generated *** results of XPS,PL,PC,EIS and DFT support the mechanism of improving photocatalytic activity based on carrier *** work provides a facile and effective method to enhance the activity of Sr Ti O_(3)-based heterojunction photocatalysts.

关键词： SrTiO_(3)/SrCO_(3) Heterojunction Photocatalytic Hydrogen evolution Nanomaterial

Beryllium carbide as diffusion barrier against Cu:First-principles study

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Chinese Physics B 2020年第1期29卷 387-392页

作者： Hua-Liang Cao Xin-Lu Cheng Hong Zhang Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China College of Physics Sichuan UniversityChengdu 610065China

Beryllium carbide is used in inertial confinement fusion(ICF)capsule ablation material due to its low atomic number,low opacity,and high melting point *** used the method of climbing image nudged elastic band(CINEB)to calculate the diffusion barrier of copper atom in the crystal of beryllium and beryllium *** diffusion barrier of copper atom in crystal beryllium is only 0.79 eV,and the barrier in beryllium carbide is larger than 2.85 *** three structures of beryllium carbide:anti-fluorite Be2C,Be2C-Ⅰ,and Be2C-Ⅲhave a good blocking effect to the diffusion of copper *** them,the Be2C-Ⅲstructure has the highest diffusion barrier of 6.09 *** research can provide useful help for studying Cu diffusion barrier materials.

关键词： diffusion barrier beryllium carbide adsorption energy

IDEA:A Utility-Enhanced Approach to Incomplete Data Stream Anonymization

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Tsinghua Science and Technology 2022年第1期27卷 127-140页

作者： Lu Yang Xingshu Chen Yonggang Luo Xiao Lan Wei Wang the College of Computer Science Sichuan UniversityChengdu 610065China the School of Cyber Science and Engineering Sichuan UniversityChengdu 610065China the Cyber Science Research Institute Sichuan UniversityChengdu 610065China

The prevalence of missing values in the data streams collected in real environments makes them impossible to ignore in the privacy preservation of data ***,the development of most privacy preservation methods does not consider missing values.A few researches allow them to participate in data anonymization but introduce extra considerable information *** balance the utility and privacy preservation of incomplete data streams,we present a utility-enhanced approach for Incomplete Data strEam Anonymization(IDEA).In this approach,a slide-window-based processing framework is introduced to anonymize data streams continuously,in which each tuple can be output with clustering or anonymized *** consider the dimensions of attribute and tuple as the similarity measurement,which enables the clustering between incomplete records and complete records and generates the cluster with minimal information *** avoid the missing value pollution,we propose a generalization method that is based on maybe match for generalizing incomplete *** experiments conducted on real datasets show that the proposed approach can efficiently anonymize incomplete data streams while effectively preserving utility.

关键词： anonymization generalization incomplete data streams privacy preservation utility

Engineering high-performance dielectric chiral shells with enhanced chiral fields for sensitive chiral biosensor

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Rare Metals 2024年第3期43卷 1197-1206页

作者： Yi-Fan Wang Shan-Shan Huang Zhen-Dong Dai Shi-Lin Xian Xuan-Nan Wu Fu-Hua Gao Yi-Dong Hou College of Physics Sichuan UniversityChengdu610065China Graduate School of Sichuan University Sichuan UniversityChengdu610065China

Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral ***,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical ***,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere *** form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,*** strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell *** chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically *** DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.

关键词： Dielectric chiral shells(DCS) Si deposition Magnetic resonance Highly sensitive sensor Chiral field

3D NUMERICAL SIMULATION ON WATER AND AIR TWO-PHASE FLOWS OF THE STEPS AND FLARING GATE PIER

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Journal of Hydrodynamics 2005年第3期17卷 338-343页

作者： ZHANGTing WUChao LIAOHua-sheng HUYao-hua StateKeyHydraulicsLaboratoryofHighSpeedFlows SichuanUniversityChengdu610065China

A new-style flood discharging dam, which consolidates the flaring gate pier and the stepped spillway for discharging the flood through the dam surface, had been applied in China. The theoretical study on it is in a beginning stage at present. The three-dimensional numerical simulation has not been reported. In this paper, the 3D numerical calculation on the two-phase flow of water and air with discharge per unit width 195m~ 3 /s· m is presented . The results indicate that there is negative pressure on the juncture of the spillway surface and the first step. There forms obvious longitudinal and transverse eddies on the steps and the velocity decreases obviously compared with the smooth spillway. The figures of the velocity distributions and the water-air two-phase flows are plotted. The results calculated on the pressure are in agreement with the experimental data. Based on the position of the negative pressure obtained from calculation, measurement points of pressure are arranged in physical model. The experimental results validate the existence of the negative pressure. Being an applied and trial study, the results obtained are of theoretical and practical significance.

关键词： flaring gate pier stepped spillway numerical simulation