检索结果-南通市图书馆

Special characteristics of fluorescence and resonance Rayleigh scattering for cadmium telluride nanocrystal aqueous solution and its interactions with aminoglycoside antibiotics

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2009年第1期52卷 76-85页

作者： LI TaiShan LIU ShaoPu LIU ZhongFang HU XiaoLi ZHANG LiPing School of Chemistry and Chemical Engineering Southwest UniversityChongqing 400715China tangshan Environmental Monitoring Center Tangshan 063000China Hebei Energy Institute of vocation and technology Tangshan 063000China

CdTe nanocrystals(CdTe NCs) were achieved by reaction of CdCl2 with KHTe solution and were capped with sodium *** product was detected by transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),energy dispersive spectroscopy(EDS),fluorescence spectra,ultraviolet-visible spectra and X-ray diffraction(XRD).The CdTe NCs are of cubic structure and the average size is about 5 *** fluorescence quantum yield of CdTe NCs aqueous solution increased from 37% to 97% after 20 d under room *** maximum λem of fluorescence changed from 543 nm to 510 nm and the blue shift was 33 *** NCs aqueous solution can be steady for at least 10 months at 4℃ in a *** resonance Rayleigh scattering(RRS) of CdTe NCs in the aqueous solution was *** maximum scattering peak was located at about 554 *** interactions of CdTe NCs with amikacin sulfate(AS) and micronomicin sulfate(MS) were investigated *** effects of AS and MS on fluorescence and RRS of CdTe NCs were *** was found that AS and MS quenched the photoluminescence of CdTe NCs and enhanced RRS of CdTe *** optimum conditions,there are linear relationships between quenching intensity(F0-F),intensity of RRS(I-I0) and concentration of AS and *** detection limits(3б) of AS and MS are respectively 3.4 ng·mL-1 and 2.6 ng·mL-1 by the fluorescence quenching method,and 15.2 ng·mL-1 and 14.0 ng·mL-1 by the RRS *** methods have high sensitivity,thus CdTe NCs may be used as fluorescence probes and RRS probes for the detection of aminoglycoside antibiotics.

关键词： CdTe nanocrystal fluorescence characteristics resonance Rayleigh scattering amikacin sulfate micronomicin sulfate

Experimental Investigation on Viscosity of Cu-H_2O Nanofluids

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) 2009年第1期24卷 48-52页

作者：李新芳 Department of Packaging & Printing Zhongshan Torch Vocation and Technology College

A procedure for preparing a nanofluid that a solid-liquid composite material consists of solid nanoparticles with sizes typically of 1-100 nm suspended in liquid was proposed. By means of the procedure, Cu-H2O nanofluids with and without dispersant were prepared, whose sediment pho-tographs and particle size distribution were given to illustrate the stability and evenness of suspension with dispersant. The viscosity of Cu-H2O nanofluid was measured using capillary viscometers. The mass fractions（w） of copper nanoparticles in the experiment varied between 0.04% and 0.16% with the temperature range of 30-70 ℃. The experimental results show that the temperature and SDBS concentration are the major factors affecting the viscosity of the nano-copper suspensions, while the effect of the mass fraction of Cu on the viscosity is not as obvious as that of the temperature and SDBS dispersant for the mass fraction chosen in the experiment. The apparent viscosity of the copper nano-suspensions decreases with the temperature increase, and increases slightly with the increase of the mass fraction of SDBS dispersant, and almost keeps invariability with increasing the mass fraction of Cu. The influence of SDBS concentration on the viscosity of nano-suspension was relatively large comparing with that of the nanoparticle concentration.

关键词： nano-Cu/water suspension SDBS kinematic viscosity capillary viscometer

Preparation and evaluation of controllable drug delivery system:A light responsive nanosphere based on β-cyclodextrin/mesoporous silica

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第10期62卷 159-167页

作者： Yi Wu Hongzhou Shang Shisheng Lai Yali Di Xiaoran Sun Ning Qiao Lihua Han Zheng Zhao Yujin Lu college of Chemical Engineering North China University of Science and TechnologyTangshan 063210China college of Materials Science and Engineering North China University of Science and TechnologyTangshan 063210China college of Pharmacy North China University of Science and TechnologyTangshan 063210China Department of Cardiology Tangshan Central HospitalTangshan 063000China

A novel light responsive nanosphere was constructed,and it was used as a drug carrier to investigate the loading and release properties of the Quercetin(QU).In this paper,mesoporous silica nanoparticles(MSN)were used as a substrate,and 3-aminopropyl triethyoxysilane was used as a surface modification agent to introduce—NH_(2),and the azobenzene-4,4’-dicarboxylic acid(AZO)was used as light responsive agent to introduce the group of—N=N—,and thenβ-cyclodextrin(β-CD)was combined with AZO through host-guest interaction to construct light responsive nanoparticles(MSN@β-CD).The structure and properties of the carrier were analyzed by FTIR,BET,XPS,TGA,XRD,SEM and *** vitro drug release studies showed the release rate of QU@MSN@β-CD(dark)was 12.19%within 72 h,but the release rate of QU@MSN@β-CD(light 10 min)was 26.09%,exhibiting a light-responsive *** CCK8 tests demonstrated that MSN@β-CD could significantly decrease the toxicity of ***,the controllable light-responsive drug delivery system has great application prospects.

关键词： Silica Drug delivery system Light-responsive b-CD Nanomaterials Support

Synthesis of Red Phosphor CaZrO_(3):Eu^(3+) for White Light-Emitting Diodes

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第2期28卷 208-211页

作者： LI Xu GUAN Li AN Jia-Yi JIN Li-Tao YANG Zhi-Ping YANG Yan-Min LI Pan-Lai FU Guang-Sheng college of Physics Science and technology Hebei UniversityBaoding 071002 tangshan vocational and Technical college Tangshan 063004

A red-emitting CaZrO_(3):Eu^(3+)phosphor has been prepared by solid state reaction and its luminescent properties are *** crystal structure is investigated by the x-ray *** energy transitions of^(5)Do→^(7)Fj(J=0,1,2,3)in Eu^(3+)ions,the emission spectrum of the phosphor shows a series of narrow bands under near-ultraviolet light and the strongest peak locates at *** emission intensity of Cai-xZrO_(3):xEu^(3+)phosphor will reach the maximum as the molar concentration of Eu^(3+)is 5mol%.

关键词： diffraction narrow ultraviolet

Microstructure Modification of Silicon Nanograins Embedded in Silicon Nitride Thin Films

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 Letters 2006年第7期23卷 1926-1928页

作者：傅广生丁文革宋维才张江勇于威 college of Physics Science and technology Hebei University Baoding 071002 Department of Physics Tangshan Teachers' College Tangshan 063000

Microstructure modification of silicon nanograins embedded in silicon nitride films by introducing hydrogen reactant in the plasma enhanced chemical vapour deposition process and their optical properties are analysed using Raman scattering, optical absorption and photoluminescence （PL） measurements. It is found that the silicon nanograins embedded in the silicon nitride （SiNx） matrix are transformed into silicon nanocrystals and the optical properties of the films change dramatically when introducing H2 into Ar-sustained plasma. The optical absorption coefficient of the films within the band gap decreases by about one order of magnitude and the PL intensity increases significantly, compared with that without hydrogen introduction. These results suggest that atomic hydrogen in the plasma has the function of crystallizing silicon nanograins and passivating defects at the silicon nanograins/SiNx interface.

关键词： CHEMICAL-VAPOR-DEPOSITION SI NANOCRYSTALS OPTICAL-PROPERTIES PLASMA PHOTOLUMINESCENCE TEMPERATURE HYDROGEN

Influence of Ionization Degrees on the Evolutions of Charged Particles in Atmospheric Plasma at Low Altitude

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and technology 2012年第8期14卷 716-722页

作者：庞学霞邓泽超贾鹏英梁伟华李霞 college of Physics Science and technology Hebei University tangshan Labor Technician college

A zero-dimensional model which includes 56 species of reactants and 427 reactions is used to study the behavior of charged particles in atmospheric plasmas with different ionization degrees at low altitude （near 0 km）. The constant coefficient nonlinear equations are solved by using the Quasi-steady-state approximation method. The electron lifetimes are obtained for afterglow plasma with different initial values, and the temporal evolutions of the main charged species are presented, which are dominant in reaction processes. The results show that the electron number density decays quickly. The lifetimes of electrons are shortened by about two orders with increasing ionization degree. Electrons then attach to neutral particles and produce negative ions. When the initial electron densities are in the range of 10l~ ~ 1014 cm-3, the negative ions have sufficiently high densities and long lifetimes for air purification, disinfection and sterilization. Electrons, O（2,-）, O（4,-） CO（4,-） and CO（3,-） are the dominant negative species when the initial electron density neo ≤ 1013 cm^（-3）, and only electrons and CO3 are left when neo 〉 1015 cm^（-3）. N（＋,2）, N＋ and O（＋,2） are dominant in the positive charges for any ionization degree. Other positive species, such as 0（＋,4）, N（＋,3）, NO（＋,2）, NO（＋,2）, Ar（＋,2） and H3O＋. H2O, are dominant only for a certain ionization degree and in a certain period.

关键词： ionization degree electron lifetime atmospheric plasma numerical simulation

Density functional theory study of B- and Si-doped carbons and their adsorption interactions with sulfur compounds

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第2期6卷 195-208页

作者： Peng Guo Hong Zhang Shuliang Dong Libao An college of Mechanical Engineering North China University of Science and TechnologyTangshanHebeiChina college of Life Sciences North China University of Science and TechnologyTangshanHebeiChina

Understanding the adsorption interactions between carbon materials and sulfur compounds has far-reaching impacts,in addition to their well-known important role in energy storage and conversion,such as lithium-ion *** this paper,properties of intrinsic B or Si single-atom doped,and B-Si codoped graphene(GR)and graphdiyne(GDY)were investigated by using density functional theory-based calculations,in which the optimal doping configurations were explored for potential applications in adsorbing sulfur *** showed that both B or Si single-atom doping and B-Si codoping could substantially enhance the electron transport properties of GR and GDY,improving their surface ***,B and Si atoms displayed synergistic effects for the codoped configurations,where B-Si codoped GR/GDY exhibited much better performance in the adsorption of sulfurcontaining chemicals than single-atom doped *** addition,results demonstrated that,after B-Si codoping,the adsorption energy and charge transfer amounts of GDY with sulfur compounds were much larger than those of GR,indicating that B-Si codoped GDY might be a favorable material for more effectively interacting with sulfur reagents.

关键词： adsorption density functional theory doping graphdiyne graphene sulfur compounds

Prediction of compressive strength based on visualization of pellet microstructure data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2021年第6期28卷 651-660页

作者： Ai-min Yang Yun-xi Zhuansun college of Science North China University of Science and TechnologyTangshan 063210HebeiChina college of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina

In recent years,with the wide application of image data visual extraction technology in the field of industrial engineering,the development of industrial economy has reached a new *** explore the interaction between the pellet microstructure and compressive strength,firstly,the pellet microstructure needed for the experiment was obtained using a Leica DM4500P *** area proportions of hematite,calcium ferrite,magnetite,calcium silicate and pore in pellet microstructure were extracted by visual extraction technology of image ***,the relationship between the area proportions of mineral components and compressive strength was established by backpropagation neural network(BPNN),generalized regression neural network(GRNN)and beetle antennae search-generalized regression neural network(BAS-GRNN)algorithms,which proves that the pellet microstructure can be used as the prediction standard of compressive *** errors of BPNN and BAS-GRNN are 5.13%and 3.37%,respectively,both of which are less than 5.5%.Therefore,through data visualization,we are able to discuss the connection between various components of pellet microstructure and compressive strength and provide new research ideas for improving the compressive strength and metallurgical performance of pellet.

关键词： Pellet microstructure Microstructure data visualization BPNN algorithm BAS-GRNN algorithm Compressive strength

Analysis of Coating Microstructure of Hot-Dip Aluminum of Deformed Low-Carbon Steel Containing Rare Earth

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2005年第S1期23卷 460-463页

作者：范力茹刘琳 college of Mathematics and Physics Yanshan University Qinhuangdao 066004 China Department of Basic Medical Tangshan Vocational Technology College Tangshan 063000 China

The coating microstructure of hot-dip aluminum (HDA) of deformed low-carbon steel containing RE was analyzed by metallography microscopy, TEM and XRD, and the forming mechanism was also discussed. The results show that, the Fe_2Al_5 phase, on whose subcrystal boundaries, Al particles with the size of 7～30 μm existing on parallel linear are, grows a strong orientation. And the spread activation energy of Al is 155.22 kJ·mol -1. In addition, the effects of deformation on coating microstructure of hot-dip aluminum and the function of RE were preliminarily analyzed.

关键词： deformed low-carbon steel hot-dip aluminum (HDA) the coating microstructure rare earths