Quantum fluids in nanoporous media——Effects of the confinement and fractal geometry

The complex behavior of such quantum fluids like liquid 4He and liquid 3He in nanoporous media is determined by spatial quantization because of geometrical confinement as well as by significant contribution from the surface atoms. In the present report we will review the procedure, results and discuss the issues for fractionalized nonextensive hydrodynamical approach to describe the properties of quantum fluids inside nanopores and propose consideration of strong correlated quantum liquid by means of fractionalized Schro¨dinger equation.     

Numerical Simulation of Two-dimensional Nonlinear Sloshing Problems

IntroductionSloshing is a phenomenon of great i mportance inengineering such as oil oscillationin a fuel tank,sloshing ofliquid propellant rocket and so on.The liquid in acontainer can be violent if the excitation frequency is closeto the natural frequency of liquid motion in the container,and a strong amplification of liquid motion will occur,which will cause high pressure to act on the container.Since sloshing is so i mportant for engineering,it hasbeen widely studied for many years,and vari…     

Liquid fragility——A key togoing deep into materials of glassy states

“Liquid fragility“ is a concept that has been widely used in the investigation on the glass community,though it was presented less than two decades ago. The concept enables the comparison between the glass-forming liquids with different dynamic characters by using a general criterion, in which the temperature scale is reduced by the glass transition temperature. In order to illuminate the significance of the concept in the fields of the glass transition,structural relaxation process and the structure of supercooled liquids, the accomplished progress and the faced challenges are summarized from different aspects such as on the correlation between dynamics and thermodynamic characters of condensed matters, on the energy landscape, on the nonexponential relaxation and on the theoretical model of microstructure and medium-range order. The tendency of investigation in “liquid fragility“ is also evaluated.     

Detection of low enersy solar neutrinos by a two-phase cryosenic e-bubble detector

A new two-phase cryogenic neutrino detector using electron bubble （e-bubble） specifically in liquid helium is proposed and being developed for real time, high rate measurements of low-energy p-p reac- tion neutrinos from the sun. The e-bubble detector is a time projection chamber-like （TPC） tracking detector. The task of such a neutrino detector is to detect the ionization of the elastically scattered target electrons by incident neutrinos, and then to characterize their energy and direction and to dis- tinguish them from radioactive backgrounds. The ionization signals are expected to be small and hence undergo avalanche amplification in the saturated vapor above the liquid phase by gas electron multi- pliers （GEMs） at high gain. Higher granularity and intrinsically suppressed ion feedback give a good spatial resolution and are the major advantages of this technology. It should be possible to construct such a detector to track charged particles down to 100--200 keV in a massive liquid helium target with fractional millimeter spatial resolution in three-dimensional space, using the GEM-based TPC with a high-resolution CCD camera, for both the electronic and light readout.     

Mechanism of liquid zinc corrosion on metals

Two kinds of materials, soluble and insoluble in liquid zinc, such as Fe and FeB, are separately dealt with. A new theory is presented for insoluble materials. Based on the theory, the surface defects of insoluble materials are the main reason that the matcrials are correded.     

Study of ionizable drugs transfer across the water／1,2-dichloroethane interface with phase volume ratio equal to unity using a three-electrode system

The electrochemical behavior of ionizable drugs (Amitripty/ine, Diphenhydramine and Trihexyphenedyl) at the water/1,2-dichloroethane interface with the phase volume ratio (r=Vo/Vw) equal to 1 are investigated by cyclic voltammetry. The system is composed of an aqueous droplet supported at an Ag/AgCI disk electrode and it was covered with an organic solution. In this manner, a conventional three-electrode potentiostat can be used to study the ionizable drugs transfer process at a liquid/liquid interface.Physicochemical parameters such as the formal transfer potential, the Gibbs energy of transfer and the standard partition coefficients of the ionized forms of these drugs can be evaluated from cyclic voltammograms obtained. The obtained results have been summarized in ionic partition diagrams, which are a useful tool for predicting and interpreting the transfer mechanisms of ionizable drugs at the liquid/liquid interfaces and biological membranes.     

New approach for screening anti—tumor compounds

A new screening approach for anticancer active compounds is presented.In this method,a target enzyme is incubated with a mixture of compounds,and then the com-plex formed by the target and small molecules is separated from the rest of the mixture by ultra-filtration.The complex that is retained on the membrane is subsequently washed with acid and small molecules that are specifically bound to the target are released and collected,then analyzed by high-performance liquid chromatograph combined with electrospray ionization mass spectrometry (HPLC/ESI-MS) analysis.We have successfully applied this method to screen anti-cancer compounds.DNA topoisomerase Ⅱ is used as a target to capture anti-tumor candidates from a mixture of combinatorial compounds,such as doxorubicin,daunorubi-cin and pravastain.     

A STUDY OF FINE DENIER POLYPROPYLENE FIBER KNITTED FABRICS'''' WET COMFORT——THE WET COMFORT STUDIED BY THE NORMAL OBJECTIVE TEST

Based on the theory of moisture vapor permeability and liquid moisture transmission through fabric, this paper is mainly concerned with the wet comfort of the fine denier polypropylene fiber knitted fabrics. The liquid water transport property the liquid water retention property, the moisture permeability property, the moisture releasing and drying property of these fabrics are tested by normal objective ways and discussed. At last, according to these properties these fabries are classified by grey model synthetic evaluation method.     

Rethinking atomic packing and cluster formation in metallic liquids and glasses

In traditional view,atomic packing is random in glasses made of metallic elements with non-directional interactions as the glass-forming liquid needs to be excited to remain in liquid state before being cooled sufficiently fast to a glass. Locally ordered packing however is possible if certain conditions are favorable,such as a strong bonding between elements,or low configuration energy of a cluster of atoms as suggested by Frank. In alloy systems made of different metallic elements,we show that Frank’s criterion alone does not necessarily lead to certain specific local ordered packing or cluster formation such as icosahedral packing. In this context,we revisit the issue of atomic packing and cluster formation,and show that an alloy system with fairly random liquid configuration could be sufficient to produce a variety of noticeable locally ordered packing with low energy,albeit largely statistical in nature. Therefore,we emphasize the importance of the system parameters such as the atomic size,alloy concentration,and interaction potential in their collective contribution to local atomic packing.     

Effective Factors on Forming Precision in Patternless Casting Manufacturing Technique

The patternless casting manufacturing (PCM) technique, which adopts a new concept of double scanning method, combines the principle of discreteness and deposition with resin-bonded sand technique. This paper is to evaluate the dimensional accuracy of sand mould on PCM. The two important factors-the liquid penetration rule in the space of particles and the shape and dimension of the agglomeration unit body, which influence the process parameters such as scanning speed, layer thickness, liquid flux on dimension accuracy, and surface qualities, were investigated systematically, thus the theoretical basis for these parameters was provided. Experiments on rapid manufacturing of sand mould were carried out, and the results of the free penetration and the constraint penetration well verified the relationship of the two factors and the process parameters.     

Experiment Study on Castex Process of AS Wire

In order to optimize the Castex process of AS wire, the systematic experiments have been done for different process parameters with self-made DZJ-II 350 Castex machine. The parameters, such as casting temperature of aluminum, flow of cooling water, extrusion ratio and the gap between the surface of wheel and that of the mould, have been mainly studied. The results show that with the increase of casting temperature or rotating speed of wheel the measured length of liquid metal zone increases too. However, the length of liquid metal zone decreases with the increase of the flow of cooling water. Moreover, the relationship between the extrusion ratio and the extrusion power is studied.     

Thickness of compound layer in steel-aluminum solid to liquid bonding

The bonding of solid steel plate to liquid aluminum was studied using rapid solidification. The surface of solid steel plate was defatted, descaled, immersed (in K₂ZrF₆ flux aqueous solution) and stoved. In order to determine the thickness of Fe-Al compound layer at the interface of steel-aluminum solid to liquid bonding under rapid solidification, the interface of bonding plate was investigated by SEM (Scanning Electron Microscope) experiment. The relationship between bonding parameters (such as preheat temperature of steel plate, temperature of aluminum liquid and bonding time) and thickness of Fe-Al compound layer at the interface was established by artificial neural networks (ANN) perfectly. The maximum of relative error between the output and the desired output of the ANN is only 5.4%. From the bonding parameters for the largest interfacial shear strength of bonding plate (226℃ for preheat temperature of steel plate, 723℃ for temperature of aluminum liquid and 15.8 s for bonding time), the reasonable thickness of Fe-Al compound layer 10.8 μm was got.     

Numerical prediction of the incremental melting and solidification process

A mathematical formulation is applied to represent the phenomena in the incremental melting and solidification process (IMSP), and the temperature and electromagnetic fields and the depth of steel liquid phase are calculated by a finite difference technique using the control volume method. The result shows that the predicted values are in good agreement with the observations. In accordance with the calculated values for different kinds of materials and different size of molds, the technological parameter of the IMS process such as the power supply and the descending speed rate can be determined.     

Chilling Tendency and Chill of Cast Iron

An analytical expression is presented for the susceptibility of liquid cast iron to solidify according to the Fe-C-X metastable system （also known as the chilling tendency of cast iron, CT）. The analysis incorporates the nucleation and growth processes associated with the eutectic transformation. The CT is related to the physicochemical state of the liquid, the eutectic cells in the flake graphite, and the number of nodules in nodular cast iron. In particular, the CT can be related to the critical wall thickness, Scr, or the chill width, Wcr, in wedge shaped castings. Finally, this work serves as a guide for understanding the effect of technical factors such as the melt chemistry, the spheroidizing and inoculation practice, and the holding time and temperature on the resultant CT and chill of the cast iron. Theoretical calculations of Sc, and Wc, compare well with experimental data for flake graphite and nodular cast iron.     

Several oxygenated monoterpenes from petals of Rosa damascena

Aim To discover the oxygenated monoterpenes that play a critical role in the biosynthetic pathway of monoterpene in Rosa damascene.Method Several kinds of isolation techniques such as liquid-liquid partition,silica column chromatography,thin layer chromatography and high performance liquid chromatography were used to separate the compounds and several identification techniques such as GC-MS and 1H-NMR were used to determine the structure of the isolated compounds.Results Three oxidized acyclic monoterpenes were obtained.They are 8-hydroxygeraniol,8-hydroxynerol and 8-hydroxylinalool.Conclusion The compounds are the important materials of pharmaceutical,cosmetic and food industries.The work has not only provided a new method for the determination of the main aromatic components of Rosa damascena,but also built up an important foundation for the study of biosynthesis of monoterpenoids in the plant.     

Simulation of macrosegregation in a 36-t steel ingot using a multiphase model

Macrosegregation is the major defect in large steel ingots caused by solute partitioning and melt convection during casting. In this study,a three-phase(liquid, columnar dendrites, and equiaxed grains) model is proposed to simulate macrosegregation in a 36-t steel ingot. A supplementary set of conservation equations are employed in the model such that two types of equiaxed grains, either settling or adhering to the solid shell, are well simulated. The predicted concentration agrees quantitatively with the experimental value. A negative segregation cone was located at the bottom owing to the grain settlement and solute-enriched melt leaving from the mushy zone. The interdendritic liquid flow was carefully analyzed, and the formation of A-type segregations in the mid-height of the ingot is discussed. Negative segregation was observed near the riser neck due to the specific relationship between flow direction and temperature gradient. Additionally, the as-cast macrostructure of the ingot is presented, including the grain size distribution and columnar–equiaxed transition.     

Microsegregation and Rayleigh number variation during the solidification of superalloy Inconel 718

The microstructure and composition of the residual liquid at different temperatures were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX) associated with the Thermo-calc software calculation of the equilibrium phase diagrams of Inconel 718 and segregated liquid. The liquid density difference and Rayleigh number variation during solidification were estimated as well. It is found that the heavy segregation of Nb in liquid prompts the precipitation of δ and Laves phase directly from liquid and the resultant quenched liquid microstructure consists of pro-eutectic γ+eutectic,or complete eutectic according to the content of Nb from low to high. The liquid density increases with decreasing temperature during the solidification of Inconel 718 and the liquid density difference is positive. The largest relative Rayleigh number occurs at 1320℃ when the liquid fraction is about 40vol%.     

Effects of surface tension on bubble growth in an extensive uniformly superheated liquid

The study of bubble growth in an extensive pool of liquid provides considerable insight into the mechanisms that play a role in bubble growth near a heated surface and in the cavitation phenomenon. This work focuses on analyzing the effects of surface tension on the growth rate for the thermally controlled stage of a single bubble in such a liquid. The conservation of energy equations, including the internal energy term for the bubble and that within boundary layer around it, are numerically solved. The complete temporal variations of the bubble in water and liquid nitrogen are investigated based on the assumption that the bubble growth is controlled only in sequence by inertia and heat. Thus, the two stages are subject to the continuity of the bubble growth, while the inertia-controlled stage is only formulated by the well-known Rayleigh solution. The thickness of the boundary layer around the bubble is also determined. The results are comparable with the Plesset-Zwick models and Forster-Zuber models, as well as available experimental data. It is found that the influence of internal energy on the rate of bubble growth is small enough to be ignored; however, the accumulative effects of the surface tension are significant and increase with a decrease in the degree of superheat.     

Application of microfluidic chip to realize controllable pH gradient

A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) is introduced here. These pH gradient chips have the advantages such as easy fabrication, controllable pH range and precision, isoelectric focusing and separation at the same time, low voltage for isoelectric focusing, and time stable pH gradient. This method has potential application to sample preparation, separation and analysis of microfluidic chips.     

Experimental study on pressure fluctuation characteristics of slug flow in horizontal curved tubes

In order to study the pressure characteristics of slug flow in horizontal curved tubes,two kinds of curved tubes with central angle 45° and 90° respectively are studied,of which are with 0. 5m circumference and 26 mm inner diameter are used. When the superficial liquid velocity or the superficial gas velocity is constant,the pressure fluctuations and the probability distribution of the average velocity of slug flow are clear for all of the five experimental conditions. The results of experiment show that the pressure characteristics of slug flow in curved tubes have periodic fluctuations. With the rise of central angle,the period of pressure fluctuation is more obvious. The system pressure of the slug flow increases with the increasing of superficial liquid/gas velocity. Meanwhile,the probability distribution of pressure signal shows regularity,such as unimodal,bimodal or multimodal.