Materials Literature
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Polygonatum odoratum,the rhizomes of Polygonatum odoratum(Mil1.) Druce have been used as traditional Chinese medicine.Steroidal saponins and homoisoflavonoids are the main active compounds.This article summarizes the chemical structures and NMR spectroscopic characteristics of steroidal saponins and homoisoflavonoids…
Al/Fe2O3nano-thermites were prepared by using ultrasonic,mechanical milling and sol-gel methods,respectively.The influence of three kinds of preparation methods on the structures and properties of the final thermites,such as crystal structure,particle size,morphology,surface area and thermal performances,were studied.…
Microstructure,strain-hardening capacity and characterization method of X70 high strain line pipe were investigated by metallographic analysis,electron backscatter diffraction,quasistatic tension and finite element method.It is concluded that X70 high strain line pipe steel does not follow the Hollimon formula in the…
With the aim to provide the theoretical basis for sustainably increasing crop yield,productivity,and nutrient management in fluvo-aquic soil of Hebei Province,the effects of the long-term application of K fertilizers and straw returning on crop yield,soil K content and potassium balance were analyzed using the data ob…
Objective: Antioxidation of different extracts from Isatidis indigotica were studied in vitro to supply the separating base of antioxidative components.Method: The extracts were prepared by macroporous resin and anion/cation exchange resin.Their antioxidant activities were assessed by two complementary test systems,na…
Microstructure and properties of 22MnB5 steel after hot stamping were studied by means of mechanical property test and microstructure analysis through SEM and TEM.The results show that the microstructure of lath martensite with high-density dislocations is obtained for the steel after hot stamping,and its mechanical p…
To investigate the effect of the initiation methods on the formation of MEFP(multiple explosively formed penetrators) warhead parameter,the process of the liners formed penetrators in three different initiation methods was simulated by using LS-DYNA software.Based on the detonation wave action theory,the shapes and ve…
Discrete Fourier transformer is the most basic mathematical tool for spectrum analysis of a stable electrical signal,which is also the transformation approach recommended by International Electro-technical Commission for harmonic and interharmonic measurement.However,when the analysis window width does not correspond…
High phonon energy oxides of WO3,SiO2and B2O3were introduced into the Er3+/Ce3+co-doped tellurite glass(TeO2-Bi2O3-TiO2) with low phonon energy,respectively.The absorption spectra in the wavelength region of 400–1700 nm,fluorescence spectra of 1.53 μm band,fluorescence lifetimes of Er3+ and Raman spectra of the glasse…
The electric coupling between the primary and secondary windings of the transformer is usually evaluated by the capacitance between the primary and secondary windings with LCR meter.This method cannot effectively consider the shielding copper foil effect and the electrical potential distribution along the winding turn…
923 of surface rolled specimens increased in MSC stage, then attained the peak value at the turning point between MSC stage and PSC stage, and finally decreased in PSC stage. At the same time, surface rolled specimens owned much less crack density than specimens without surface rolling during the whole fatigue process…
Copper powder was added to the hydrophilic fixed abrasive pad to improve its polishing performance.The influence of copper content on the pad′s physical and chemical properties,as well as on its material removal rate and surface roughness in polishing K9 optical glass,was studied.The results showed that with the incre…
The effects of variable parameters on HPCC(high premixed charge combustion)combustion fuelled with gasoline/diesel dual fuel are conducted in a modified single-cylinder diesel operating at engine speed 1,500,r/min and IMEP(indicated mean effective pressure)of 0.9,MPa.Results show that the HPCC combustion can be optimi…
For the uneven electrical distribution on screening electrode of ultra-high voltage AC bushing,hence often leading to corona and dielectric puncture,the electric field and voltage distribution of ultra-high voltage AC bushing are evaluated with 3D FEM.It is found that the field strength on the upper and lower arcs of…
In order to study thermal hazard of ABVN and the influence of impurities,C600 trace calorimetric apparatus was used to make the experiment of the thermal decomposition of ABVN and mixed storage system.The corresponding kinetic and thermodynamic parameters based on experimental data were obtained.Semenov model was used…
Fouling resistances of Songhua River cooling water in a plate heat exchanger were dynamically monitored and six kinds of water quality parameters of Songhua River at eight different times including dissolved oxygen,electrical conductivity,turbidity,Cl,alkalinity and Ca2 were tested,as well as the grey relational analy…
Nanocomposite PbO·SnO2 was prepared by solid state reaction from Pb(NO3)2,SnCl4·5H2O with NaOH at room temperature.The composition,particle size and morphology of nanocomposite PbO·SnO2 were characterized by XRD,TEM,FT-IR.and SEM-EDS.The effects of nanocomposite PbO·SnO2 on the combustion properties of double-base pro…
Melamine could rapidly induce the aggregation of gold nanoparticles(AuNPs),thereby resulting in red-to-purple(even blue) color change.Thus,a rapid detection method for melamine in milk and eggs using AuNPs as colorimetric probe has been established.The experimental conditions was optimized in detail,ultimately,the ana…
The mechanism of the mixed abrasives was analyzed and the SiO2 abrasive was compared with the mixed abrasives on the sapphire substrate removal rate.The result showed that adding nanometer grade alumina with the concentration of 20mL/L in the main abrasive could make the chemical action balance with the mechanical act…
The objective of the present study was to investigate the mechanisms for the inhibition of Bacillus cereus by Fructus Mume extract.The effect of Fructus Mume extract on the integrity of cell wall was studied by determining the content of alkaline phosphatase(AKP).The contents of extracellular proteins were assayed by…