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The precursor compound of two types of ZnSe magic-sized clusters

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Nano Research 2022年第1期15卷 465-474页

作者： xingxia Yang Meng Zhang Qiu Shen Yang Li Chaoran luan Kui yu Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China Engineering Research Center in Biomaterials Sichuan UniversityChengdu 610065China Department of Ophthalmology West China School of MedicineWest China HospitalSichuan UniversityChengdu 610065China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065China

Precursor compounds(PCs)link quantum dots(QDs)and magic-sized clusters(MSCs),which is pivotal in the conversion between QDs and ***,for the first time,we report the transformation,synthesis,and composition of a type of ZnSe *** PCs can be directly transformed to two different MSCs with the assistance of octylamine and acetic acid at room *** two types of MSCs exhibit sharp absorption peaks at 299 and 328 nm which are denoted as MSC-299 and *** the preparation of ZnSe PCs,diphenylphosphine(DPP)as an additive plays a key role which not only inhibits the thermal decomposition of Zn precursor,but also acts as a reducing agent to reduce the by-products produced in the *** composition was explored by X-ray photoelectron spectroscopy,energy dispersive spectrometer,matrix-assisted laser desorption/ionization time-of-flight mass spectra with ZnSe PC powder appeared as white powder after purifying by toluene(Tol)and methanol(MeOH).The results indicate that the molar ratio of Zn/Se is 2:1 with a molecular of〜3,350 ***,we propose that the molecular formula of ZnSe PCs is Zn_(32)Se_(16).In addition,at the molecular level,the covalent bond of Zn-Se is formed in ZnSe *** study offers a deeper understanding of the transformation from PCs to MSCs and for the first time proposes the composition of ***,this research provides us with a new understanding of the role of DPP in the synthesis of colloidal semiconductor nanoparticles.

关键词： ZnSe magic-size clusters(MSCs) precursor compounds(PCs) purification composition

Metagenomic insights into microorganisms and antibiotic resistance genes of waste antibiotic fermentation residues along production,storage and treatment processes

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Journal of Environmental Sciences 2024年第2期136卷 45-55页

作者： Ziming Han Xiao luan Haodi Feng Yanqin Deng Min Yang yu Zhang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery Beijing 100085China Wuhan Agricultural Inspection Center Wuhan 430016China University of Chinese Academy of Sciences Beijing 100049China

Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production *** is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed ***,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by ***,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of *** expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation ***,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open *** genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of *** from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining ***,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly *** sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ***,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria befor

关键词： Pharmaceutical manufacturing Antibiotic mycelia residue Antibiotic resistance bacteria Thermal treatment Solid waste

Modeling and simulation of solvent behavior and temperature distribution within long stick propellants with large web thickness undergoing drying

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Defence Technology（防务技术） 2023年第10期28卷 42-55页

作者： Enfa Fu Qianling Liu yu luan Yao Zhu Weidong He Zhenggang Xiao Key Laboratory of Special Energy Materials Ministry of EducationSchool of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing210094People's Republic of China

Drying is a complicated physical process which involves simultaneous heat and mass transfer in the removal of solvents inside *** drying techniques may result in the formation of a hard skin layer near the surface to block the free access of most solvent through for long stick propellants with large web thickness,which lead to lower drying efficiency and worse drying *** study aims to gain a comprehensive understanding of drying process and clarify the mechanism of the blocked layer near the propellant surface.A new three-dimensional coupled heat and mass transfer(3D-CHMT)model was successfully developed under transient *** drying experiment results show that the 3DCHMT model could be applied to describe the drying process well since the relative error of the content of solvent between simulation and experiment values is only 5.5%.The solvent behavior simulation demonstrates that the mass transfer process can be divided into super-fast(SF)and subsequent minorfast(MF)stages,and the SF stage is vital to the prevention of the blocked layer against the free access for solvent molecules inside propellant *** effective solvent diffusion coefficient(Deff)of the propellant surface initially increases from 3.4×10^(-6)to 5.3×10^(-6)m^(2)/s as the temperature increases,and then decreases to 4.1×10^(-8)m^(2)/s at 60-100 *** value of Deffof surface between 0-1.4 mm has a unique trend of change compared with other regions,and it is much lower than that of the internal at100 min under simulation ***,the temperature of the propellant surface increases rapidly at the SF stage(0-100 min)and then very slowly *** the evolution of Deffand temperature distribution demonstrate that the blocked layer near the propellant surface has been formed in the time period of approximately 0-100 min and its thickness is about 1.4 *** mitigate the formation of blocked layer and improve its drying quality of finial prop

关键词： Stick propellants Drying Large web thickness 3D numerical modeling Heat transfer Solvent behavior

High-resolution topography measurement of PACMANUS and DESMOS hydrothermal fields using a ROV in Manus basin

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Science Bulletin 2016年第15期61卷 1154-1156页

作者： Xiaochuan Ma Jun Yan Zhendong luan xin Zhang Cui-E Zheng Dajun Sun Institute of Oceanology Chinese Academy of Sciences KeyLaboratory of Marine Geology and EnvironmentQingdao 266071 China Harbin Engineering University Ringgold Standard Institution College of Underwater Acoustic Engineering Harbin 150001China

In China,the lack of high-resolution topographical data from small target areas limits our understanding of deep sea ***,the high-resolution topography of the PACMANUS hydrothermal field and the DESMOS hydrothermal field were measured using a remotely operated underwater vehicle(ROV)with a multibeam system.A composition positioning system on the ROV provided high positioning accuracy(greater than 0.5 m).The data show that four knolls develop in the PACMANUS field on the crest of the Pual ***

关键词：高分辨率地形测量 ROV 热场海盆组合定位系统目标区域多波束系统

Behavior of pure and modified carbon/carbon composites in atomic oxygen environment

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 190-195页

作者： Xiao-chong Liu Lai-fei Cheng Li-tong Zhang xin-gang luan Hui Mei Science and Technology on Thermostructural Composite Materials Laboratory School of Materials Science and Engineering Northwestern Polytechnical University

Atomic oxygen （AO） is considered the most erosive particle to spacecraft materials in low earth orbit （LEO）. Carbon fiber, car-bon/carbon （C/C）, and some modified C/C composites were exposed to a simulated AO environment to investigate their behaviors in LEO. Scanning electron microscopy （SEM）, AO erosion rate calculation, and mechanical property testing were used to characterize the material properties. Results show that the carbon fiber and C/C specimens undergo significant degradation under the AO bombing. According to the effects of AO on C/C-SiC and CVD-SiC-coated C/C, a condensed CVD-SiC coat is a feasible approach to protect C/C composites from AO degradation.

关键词： atomic oxygen oxidation carbon/carbon composites ceramic matrix composites

Measurements of non-equilibrium and equilibrium temperature behind a strong shock wave in simulated martian atmosphere

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Acta Mechanica Sinica 2012年第5期28卷 1296-1302页

作者： xin Lin Xi-Long yu Fei Li Shao-Hua Zhang Jian-Guo xin xin-yu Zhang School of Optoelectronics Beijing Institute of Technology State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of Sciences

Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- resolved spectra of the Av = 0 sequence of the B^2∑^＋ → X^2∑^＋ electronic transition of CN have been observed through optical emission spectroscopy （OES）. A new method, which is based on fitting high resolution spectrum for rotational and vibrational temperatures measurement, is proposed to diag- nose temperature distribution behind the shock wave. It is estimated that the current scheme has the maximum deviation less than 8% （lσ） for vibrational temperature measurement through detailed analysis of the influence of the uncertainties of spectroscopic constants and spectral resolution. Radiation structure of the shock layer, including induction, relaxation and equilibrium process, and corresponding rotational and vibrational temperatures are obtained through time gating OES diagnostics with sub-microsecond temporal resolution. The present extensive results will strongly benefit the reaction rate estimation and computational fluid dynamics （CFD） code validation in high enthalpy Mars reentry chemistry.

关键词： Radiation measurements - Shock wave Marsre-entry Rotational temperature Vibrational temperature

二氢杨梅素分子结构与性质的密度泛函理论研究

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原子与分子物理学报 2025年第1期42卷 29-34页

作者：辛国鹏毛敏刘信平马文涛马杰张煜湖北民族大学化学与环境工程学院恩施445000

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H... 详细信息

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H23)附近;而亲电活性位点位于氧原子(O32)及其附近.前线分子轨道研究结果表明二氢杨梅素分子的最高占据轨道(HOMO)都位于酮基氧(O32)和羟基氧(O20)附近,说明这些位点易与亲电试剂反应.而最低空轨道(LUMO)位于碳原子(C12、C13、C14)区域,表明这些区域可与亲核试剂反应.简缩福井函数(f)结果证实了位于C-O-C键中的氧原子的f-值的亲电活性较其他位点氧原子大;而位于C8碳原子的f^(+)值较大,因此该位点亲核活性较强.通过理论计算所得到的二氢杨梅素的红外光谱数据与实验所得到的红外光谱数据相差不大,这就说明理论计算结果是较为可靠的.从而为实验和理论研究二氢杨梅素结构与性质的关系提供了一定的理论参考.

关键词：二氢杨梅素密度泛函理论反应活性位点量子化学计算

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Compatibilization of PBT/PP Blends by Adding Side-chain Liquid Crystalline Ionomer with Quaternary Pyridinium Groups

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Chemical Research in Chinese Universities 2011年第1期27卷 140-144页

作者： XU xin-yu Department of Polymer Materials and Engineering School of Chemistry and Materials Science Liaoning Shihua University Fushun 113001 P R. China

A side-chain liquid crystalline ionomer（SLCI） was synthesized by grafting copolymerization of 4-（4-ethoxybenzoyloxy）-4＇-allyloxybiphenyl and N-allyl-pyridium bromide on polymethylhydrosiloxane. The SLCI was blended with polypropylene（PP） and polybutylene terephthalate（PBT） by melt mixing. The thermal behavior, liquid crystalline properties, morphological structure, and mechanical properties of the blends were investigated by differential scanning calorimetry（DSC）, polarizing optical microscopy（POM）, scanning electron microscopy（SEM）, and tensile measurement. When a proper amount of SLCI was added, fine configurations were formed in the PBT/PP/SLCI blend system, and the mechanical properties were improved due to improved adhesion at the interface. When excess SLCI was added, an inhomogeneous structure resulted, which caused the mechanical properties to deteriorate.

关键词： Poly(butylent terephthalate) Poly(propylene) Liquid crystalline ionomer Compatibilization

Superdeformed Bands of ^(150)Gd in the Interacting Boson Model

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Chinese Physics Letters 1998年第8期15卷 561-563页

作者： LIU yu-xin Department of Physics Peking UniversityBeijing 100871 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080

The electric quadrupole transitionγ-ray energies and the dynamical moments of inertia of the five superdeformed(SD)bands of ^(150)Gd have been investigated with a four parameter approach inspired of the interacting boson *** calculated results agree with experimental data *** indicates that the four parameter approach is powerful in describing both the yrast SD band and the excited SD bands of even-even nucleus no matter whether the bands are built upon some extra single particle excitations.

关键词： bands excited excitation