复合晶核剂对混合玻璃体系制备微晶玻璃的影响

为了能在低温下制备出微晶玻璃陶瓷结合剂,以适用于超硬磨具的制备,本试验以两种玻璃料的混合体系作为研究对象,以ZrO_(2)和P_(2)O_(5)作为晶核剂。探究了晶核剂的复合添加量、不同复合比例对混合玻璃体系析晶性能与力学性能的影响。对烧结样品进行X射线衍射分析、抗弯强度测试和扫描电镜分析。结果表明,在ZrO_(2)+P_(2)O_(5)的总含量为4.5wt%的情况下,且ZrO_(2)与P_(2)O_(5)的质量比为2∶1时,烧结样品中析出的晶体数量最多,此时抗弯强度出现了最大值74.95 MPa。

复合晶核剂对混合玻璃体系制备微晶玻璃的影响

为了在低温下制备出微晶玻璃陶瓷结合剂,以适用于超硬磨具的制备,本实验以两种玻璃料的混合体系作为研究对象,以Zr O_2和P_2O_5作为晶核剂,探究了晶核剂的复合添加量、不同复合比例对混合玻璃体系析晶性能与力学性能的影响。同时,对烧结样品进行X射线衍射分析、抗弯强度测试和扫描电镜分析。结果表明,在Zr O_2+P_2O_5的质量分数为4.5%的情况下,且Zr O_2与P_2O_5的质量比为2∶1时,烧结样品中析出的晶体数量最多,此时抗弯强度出现了最大值,为74.95 MPa。

Effects of liquefaction-induced large lateral ground deformation on pile foundations

The pile-soil system interaction computational model in liquefaction-induced lateral spreading ground was established by the finite difference numerical method.Considering an elastic-plastic subgrade reaction method,numerical methods involving finite difference approach of pile in liquefaction-induced lateral spreading ground were derived and implemented into a finite difference program.Based on the monotonic loading tests on saturated sand after liquefaction,the liquefaction lateral deformation of the site where group piles are located was predicted.The effects of lateral ground deformation after liquefaction on a group of pile foundations were studied using the fmite difference program mentioned above,and the failure mechanism of group piles in liquefaction-induced lateral spreading ground was obtained.The applicability of the program was preliminarily verified.The results show that the bending moments at the interfaces between liquefied and non-liquefied soil layers are larger than those at the pile＇s top when the pile＇s top is embedded.The value of the additional static bending moment is larger than the peak dynamic bending moment during the earthquake,so in the pile foundation design,more than the superstructure＇s dynamics should be considered and the effect of lateral ground deformation on pile foundations cannot be neglected.

Enhanced HMF yield from glucose with H-ZSM-5 catalyst in water–tetrahydrofuran/2-butanol/2-methyltetrahydrofuran biphasic systems

With the aim of achieving a high 5-hydroxymethylfurfural(HMF)yield from glucose with H-ZSM-5 catalyst at low cost,three inexpensive biphasic reaction systems,H2O?tetrahydrofuran(THF),H2O?2-methyltetrahydrofuran(MeTHF)and H2O?2-butanol,were discovered and proved to be particularly effective in promoting the formation of HMF from glucose over H-ZSM-5 zeolite.In order to determine the optimal process conditions,the effects of various experimental variables,such as reaction temperature,reaction time,catalyst dosage,volume of organic solvent,as well as inorganic salt type on glucose conversion to HMF in three systems were investigated in detail.It was found that under optimal reaction conditions,H2O?THF,H2O?2-butanol and H2O?MeTHF allowed the glucose dehydration process to achieve HMF yields of up to 61%,59%,and 50%,respectively.Moreover,in the three biphasic systems,the H-ZSM-5 catalyst was also demonstrated to maintain excellent stability.Thus,the catalytic approach proposed in this paper can be believed to have potential prospects for industrially efficient and low-cost production of HMF.

Measurement of Mass Transfer Coefficients and Their Modelling of Continuous Counter-Current Aqueous Two-Phase System in a Packed Extraction Column

Overall dispersed side volumetric mass transfer coefficients for protein and amino acids were measured in continuous countercurrent PEG4000/KHP aqueous two-phase systems in a 57mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The average relative deviation between calculated values and experimental data ranges from 8% to 14%.

Efficient Separation of Butyric Acid by an Aqueous Two-phase System with Calcium Chloride

One of the bottlenecks for bioproduction of butyric acid as bulk chemical is the difficulty in separating butyric acid from the fermentation broth,compared with the petroleum-based chemical synthesis method.In the present work,a novel separation methodology was developed based on an aqueous two-phase system with inor-ganic salts.Calcium chloride was screened out for effective separation of butyric acid from butyric acid-water-salt systems.Within appropriate concentration range of butyric acid and salt,butyric acid was enriched in the upper phase and most of calcium ions remained in the lower phase.This"salting out"effect is very efficient to separate butyric acid from the simulated butyrate fermentation broth,which consists of butyric acid and acetic acid with concentration ratio of 4︰1,so that the final ratio of butyric acid/acetic acid in the upper phase is improved to 9.87. The aqueous two-phase system was used to separate butyric acid from the actual fermentation broth with satisfac-tory result.

Measurement and Correlation of Partition Coefficients of Baicalin in EOPO/Salt Aqueous Two-Phase Systems

The partition coefficients of baicalin were measured in ethylene oxide and propylene oxide (EOPO)/salt aqueous two-phase systems at 298.15K. It was found that most of baicalin partitioned into EOPO-rich phase. The partition coefficients of baicalin varied from 10 to 120. The effect of various factors, including tie-line length, salt composition, molecular weight of EOPO, and solution pH, on the partition behavior was investigated in EOPO/salt systems. Furthermore the partition coefficients of baicalin were correlated using the modified Diamond-Hsu model. Good agreement with experimental data is obtained. The average relative deviations are less than 5.0%.

Study on the Phase Equilibria of Hard Core Asakura-Oosawa Fluids with Renormalization-group Theory

An analytical equation of state (EOS) for hard core Asakura-Oosawa (AO) fluid is established by combining the AO potential, the first-order perturbation theory and the radial distribution function (RDF) for the hard sphere fluid.The phase equilibria are studied by using the renormalization-group (RG) theory. The obtained results agree well with the simulation data. Investigation shows that the attractive range parameter plays an important role in the phase equilibria for AO fluid.

Solutions Of Boundary-Value Problems of the Generalized Theory of Couple-Stress Thermodiffusion

We have considered the basic dynamic homogeneous system of partial differential equations of generalized Green-Lindsay couple-stress thermodiffusion on the plane for homogeneous, isotropic elastic media with the centre of symmetry. We have constructed regular solution of the boundary problems on the line. In the works are obtained in quadrates the solution of the boundary-value problem of the generalized Green-Lindsay theory of couple-stress thermodiffusion, when on border of area are given： the component of normal of displacement vector, the component of touching of stress vector, rotations, flow of heat and flow of diffusion.

Thermodynamics and kinetics of liquid-liquid phase separation in poly（acrylonitrile-co-maleic acid）/DMSO/nonsolvent system

Based on that the poly（acrylonitrile-co-maleic acid） （PANCMA）/DMSO/nonsolvent system agreed with the empirical linearized cloud point （LCP） relation, thermodynamics and kinetics of liquid-liquid phase separation behavior of this system were investigated through coagulation value and phase diagram. It was found that adding solvent to the coagulation bath decreased the coagulation power and diffusion exchange rate of solvent and nonsolvent, and the system became more stable thermodynamically. On the other hand, the system with poly（vinyl alcohol） （PVA） as additive was thermodynamically less stable than that with poly （vinylpyrrolidone） （PVP） and/or not. In addition, the polymer solution system at higher temperature became thermodynamically more stable and had a higher nonsolvent tolerance. Moreover, higher temperature heightened the diffusion exchange rate of solvent and nonsolvent and accelerated phase separation. It is indicated that phase diagram and coagulation value offered some useful and necessary thermodynamic and kinetic information to establish optimal conditions and guide practical membrane fabrication in the results.

Identification of Telecom Operators' Core Distribution Channels Based on Strategic Value Evaluation System

The strategic value evaluation ofphysical channels is the main purpose of thispaper.To interpret this value,we refine finance,location and competition dimensions.Atotal of 166 social high-star channels are selected as empirical samples.Practice showsthat all second-layer indicators can be quantified by information system or artificial collection.The weight of three first-layer indicatorscan be defined by correlation analysis.The valuecomprehensive ranking of the channels is clearbased on the first-layer and second-layer indicators.In the sample group in this study,theweight of location value is higher.The resultson channels' strategic value research may provide further insights on business value,servicevalue and other related fields.

Phase-transfer interface promoted corrosion from PtNi10 nanoctahedra to Pt4Ni nanoframes

A novel two-phase approach towards the corrosion of PtNil0 nanoctahedra has been developed. In this strategy, the active component of Ni in oil-soluble PtNil0 nanoctahedra which resided in the upper toluene phase, suffered from etching and was then transferred into a lower aqueous phase with coordination by ethylenediaminetetraacetate （EDTA）. Due to the existence of the phase-transfer interface promoted by EDTA, the corrosion reaction proceeded at an accelerated rate under the mild conditions. Specifically, the resultant products of octahedral Pt4Ni nanoframes were successfully fabricated for the first time, and PtNi4 porous octahedra could be obtained when the dosage of EDTA-2Na was reduced. After a systematic study of this two-phase system, a ＂synergetic corrosion＂ mechanism is proposed to account for the formation of octahedral Pt4Ni nanoframes, involving contributions from many species （i.e., O2, H2O, H＋, OAm, and EDTA^4-）. As a result of the fascinating three-dimensional geometry of Pt4Ni nanoframes and PtNi4 porous octahedra, both of the corroded nanocrystals showed superior activity over the pristine PtNi^o nanoctahedra for ethanol electrooxidation in alkaline media and hydrogenation of nitrobenzene.

A general thermodynamic analysis and treatment of phases and components in the analysis of phase assemblages in multicomponent systems

Systematic thermodynamic analysis reveals that an essential condition for the thermodynamically valid chemographic projec-tions proposed by Greenwood is completely excessive.In other words,the phases or components from which the projection is made need not be pure,nor have their chemical potentials fixed over the whole chemographic diagram.To facilitate the analy-sis of phase assemblages in multicomponent systems,all phases and components in the system are divided into internal and external ones in terms of their thermodynamic features and roles,where the external phases are those common to all assem-blages in the system,and the external components include excess components and the components whose chemical potentials(or relevant intensive properties of components) are used to define the thermodynamic conditions of the system.This general classification overcomes the difficulties and defects in the previous classifications,and is easier to use than the previous ones.According to the above classification,the phase rule is transformed into a new form.This leads to two findings:(1) the degree of freedom of the system under the given conditions is only determined by the internal components and phases;(2) different external phases can be identified conveniently according to the conditions of the system before knowing the real phase rela-tions.Based on the above results,a simple but general approach is proposed for the treatment of phases and components:all external phases and components can be eliminated from the system without affecting the phase relations,where the external components can be eliminated by appropriate chemographic projections.The projections have no restriction on the states of the phases or the chemical potentials of components from which the projections are made.The present work can give a unified ex-planation of the previous treatments of phases and components in the analysis of phase assemblages under various specific conditions.It helps to avoid potential misunderstandings or errors in the topological analysis of phase relations.

Transport phenomena for a spherical particle in pure extensional and simple shear flows

Particles(including solid particles,liquid drops and gas bubbles)are ubiquitous in a large number of natural processes as well as in industrial productions.Their behaviors are of fundamental importance in multiphase systems since the existence of such dispersed particles influences the momentum,mass and heat transport behaviors in these systems.Up to now,a vast body of literature has been published in dealing with the transport phenomena related to a particle surrounded by a fluid under various physical circumstances.In this paper,principal research results for the transport process of a single spherical particle in pure extensional and simple shear flows presented in the literature,including our recent work,are generally reviewed in order to give a comprehensive knowledge in this area.