Liquid–liquid phase transition in confined liquid titanium

We report the layering and liquid–liquid phase transition of liquid titanium confined between two parallel panel walls.Abnormal changes in the volume and the potential energy confirm the existence of the liquid–liquid phase transition of the liquid titanium. The typical feature of the liquid–liquid phase transition is layering, which is induced by the slit size,pressure and temperature. We highlight the fact that the slit size and pressure will determine the number of layers. In addition, with the change in the slit size, the density of the confined liquid expresses a fluctuating law. The phase diagram of the layering transition is drawn to clearly understand the layering. This study provides insights into the liquid–liquid phase transition of liquid metal in a confined space.

Kinetic characteristics of liquid phase sintering of mechanically activated W-15wt%Cu powder

The kinetic characteristics of W grain growth operated by diffusion controlled Oswald ripening （DOR） during liquid phase sintering were studied. A liquid phase sintering of W-15wt%Cu was carried out by pushing compacts into a furnace at the moment when the temperature increased to 1340℃ for different sintering times. The results show that liquid phase sintering produces the compacts with considerably low relative density and inversely, rather high homogeneity. On the basis of the data extracted from the SEM images, the kinetic equation of W grain growth, G^n = G0^n ＋ kt, is determined in which the grain growth exponent n is 3 and the grain growth rate constant k is 0.15 μm^3/s. The cumulative normalized grain size distributions produced by different sintering times show self-similar. The cumulative distribution function is extracted from the curves by non-linear fitting. In addition, the sintering kinetic characteristics of W-15wt%Cu compacts were also investigated.

RESEARCH ON METHOD TO CALCULATE VELOCITIES OF SOLID PHASE AND LIQUID PHASE IN DEBRIS FLOW

Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction, then general equations of velocities of solid phase and liquid phase were founded in two-phase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham＇s rheology equation of liquid phase and Bagnold＇s testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.

Influence of gangue existing states in iron ores on the formation and flow of liquid phase during sintering

Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size on the assimilation characteristics and fluidity of liquid phase of five different iron ores were analyzed in this study. Next, the mechanism based on the reaction between gangues and sintering mate- dais was unraveled. The results show that, as the SiO2 levels increase in the iron ores, the lowest assimilation temperature （LAT） decreases, whereas the index of fluidity of liquid phase （IFL） increases. Below 1.5wt%, Al2O3 benefits the assimilation reaction, but higher concentra- tions proved detrimental. Larger quartz particles increase the SiO2 levels at the local reaction interface between the iron ore and CaO, thereby reducing the LAT. Quartz-gibbsite is more conductive to assimilation than kaolin. Quartz-gibbsite and kaolin gangues encourage the forma- tion of liquid-phase low-Al2O3-SFCA with high IFL and high-Al2O3-SFCA with low IFL, respectively.

Enhancement of Sensitivity for Determination of Phenols in Environmental Water Samples by Single-drop Liquid Phase Microextraction Using Ionic Liquid prior to HPLC

A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility （RSD, n=6） were in the range 5.4%-8.9% and detection limits （S/N=3） were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate （EDTA） into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.

Growth and characteristics of InAsSb epilayers with a cutoff wavelength of 4.8 μm prepared by one-step liquid phase epitaxy

InAsSb epilayers with a cutoff wavelength of 4.8 μm have been successfully grown on InAs substrates by one-step liquid phase epitaxy （LPE） technology. The epilayers were characterized by X-ray diffraction （XRD）, Fourier transform infrared （PTIR） transmittance measurements and scanning electron microscopy （SEM）. The influence of different growth conditions on the optical and structural properties of the materials was studied. The results revealed that the good crystalline quality, mirror smooth surface and flat interface of InAsSb epilayers were achieved. They benefited from optimized growth conditions, i.e., sufficient homogeneity of the growth melt and a very slow cooling rate.

A two-step transient liquid phase diffusion bonding process of T91 steels

In this study, a two-step heating process is introduced for transient liquid phase （ TLP） diffusion bonding fo r sound joints with T91 heat resistant steels. At first, a short-time higher temperature heating step is addressed to melt the interlayer, followed by the second step to complete isothermal solidification at a low temperature. The most critical feature of our new method is producing a non-planar interface at the T9／ heat resistant steels joint. We propose a transitional liquid phase bonding of T91 heat resistant steels by this approach. Since joint microstructures have been studied, we tested the tensile strength to assess joint mechanical property. The result indicates that the solidified bond may contain a primary solid-solution, similar composition to the parent metal and free from precipitates. Joint tensile strength of the joint is not lower than parent materials. Joint bend＇s strengths are enhanced due to the higher metal-to-metal junction producing a non-planar bond lines. Nevertheless, the traditional transient liquid phase diffusion bonding produces planar ones. Bonding parameters of new process are 1 260 °C for 0. 5 min and 1 230 °C fo r 4 min.

Highly selective ethylbenzene production through alkylation of dilute ethylene with gas phase-liquid phase benzene and transalkylation feed

A novel industrial process was designed for the highly selective production of ethylbenzene. It comprised of a reactor vessel, vapor phase ethylene feed stream, benzene and transalkylation feed stream. Especially the product stream containing ethylbenzene was used to heat the reactor vessel, which consisted of an alkylation section, an upper heat exchange section, and a bottom heat exchange section. In such a novel reactor, vapor phase benzene and liquid phase benzene were coexisted due to the heat produced by isothermal reaction between the upper heat exchange section and the bottom heat exchange section. The process was demonstrated by the thermodynamic analysis and experimental results. In fact, during the 1010 hour-life-test of gas phase ethene with gas phase-liquid phase benzene alkylation reaction, the ethene conversion was above 95%, and the ethylbenzene selectivity was above 83% （only benzene feed） and even higher than 99% （benzene plus transalkylation feed）. At the same time, the xylene content in the ethylbenzene was less than 100 ppm when the reaction was carried out under the reaction conditions of 140-185℃ of temperature, 1.6-2.1 MPa of pressure, 3.0-5.5 of benzene/ethylene mole ratio, 4-6 v% of transalkylation feed/（benzene＋transalkylation feed）, 0.19-0.27 h^-1 of ethene space velocity, and 1000 g of 3998 catalyst loaded. Thus, compared with the conventional ethylbenzene synthesis route, the transalkylation reactor could be omitted in this novel industrial process.

Liquid phase epitaxy magnetic garnet films and their applications

Liquid phase epitaxy （LPE） is a mature technology. Early experiments on single magnetic crystal films fabricated by LPE were focused mainly on thick films for microwave and magneto-optical devices. The LPE is an excellent way to make a thick film, low damping magnetic garnet film and high-quality magneto-optical material. Today, the principal challenge in the applied material is to create sub-micrometer devices by using modern photolithography technique. Until now the magnetic garnet films fabricated by LPE still show the best quality even on a nanoscale （about 100 nm）, which was considered to be impossible for LPE method.

Features of microstructure and fracture in the transient liquid phase bonded aluminium-based metal matrix composite joints

Transient liquid phase (TLP) bonded aluminium based metal matrix composite (MMC) joints can be classified into three distinct regions, i.e. the particulate segregation region, the denuded particulate region and the base material region. The microstructure of the particulate segregation region consists of alumina particulate and Al alloy matrix with the Al 2Cu and MgAl 2O 4. It contains more and smaller alumina particulates compared with the base material region. The TLP bonded joints have the tensile strength of 150 MPa ～200 MPa and the shear strength of 70 MPa ～100 MPa . With increasing tensile stress, cracks initiate in the particulate segregation region, especially in the particulate/particulate interface and the particulate/matrix interface, and propagate along particulate/matrix interface, througth thin matrix metal and by linking up the close cracks. The particulate segregation region is the weakest during tensile testing and shear testing due to obviously increased proportion of weak bonds (particulate particulate bond and particulate matrix bond).

Dynamic microwave-assisted extraction combined with liquid phase microextraction based on the solidification of a floating drop for the analysis of organochlorine pesticides in grains followed by GC

A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.

Effects of Ni addition on liquid phase separation and giant magnetoresistance of Cu-Co alloys

The effects of Ni addition on the liquid phase separation and giant magnetoresi stance (GMR) of Cu Co alloys were discussed. The results reveal that Ni additio n can partially restrain the liquid phase separation of Cu Co alloys, resultin g in a decrease of volume fraction for the Co rich particles separated from the liquid phase and in refined microstructures. The composition analyses indicate t hat Ni is dissolved in both the Co rich and the Cu rich phases, but Ni content in the Co rich phase is much higher than that in the Cu matrix. At the same ti me, Ni addition enhance the solubility between Cu and Co, especially Cu in Co s olid solution. Ni alloying into Cu Co alloys can fully prevent the liquid phase separation during melt spinning, which is very beneficial to improve GMR of Cu Co alloys.

Liquid Phase Behavior during Elevated Temperature Deformation of the Fine-Grained 5083 Al Alloy

The liquid phase behavior of the fine-grained 5083 AI alloy obtained through thermomechanical process was investigated during the tensile tests in a temperature range of 380-570℃ and strain rate range of 4.17× 10^-4- 1.0× 10^-2 s^-1. The maximum elongation 530% of the fine-grained 5083 AI alloy was obtained at 550℃ and 4.17× 10^-4 s^-1. Fracture analysis by scanning electron microscopy （SEM） indicated that the formation of filament （formed by liquid phase） was greatly affected by the tensile temperature and strain rate. The results also showed that the optimum morphology of formed filament was obtained at 550℃ and a strain rate of 4.17× 10^-4 s^-1. The effect of liquid phase on superplastic deformation of the alloy was further discussed.

Liquid Phase Catalytic Oxidation of Low-Concentration H_2S in Cerium Doped Absorption Solution

For the goal of sulfur recovery, most methods are aimed at the tail gas with high-concentration H2S, but few effective methods are used for low-concentration H2S. In this work, Low-concentration H2S could be purified well by liquid phase catalytic oxidation (LCO), and the sulfur resource could also be recovered. The absorption solution was prepared by FeCl3 and sulfosalicylic acid. Under the experimental conditions, the conversion of H2S to S could be maintained above 94% at 60 ℃. In order to enhance the economical efficiency of LCO method, the absorption solution was modified by doping Ce, and a series of experiments were designed to investigate its performance. The results showed that the conversion of H2S had no obvious improvement, but above 98% conversion could be gained at 60 ℃, and the H2S conversion rate was enhanced. The optimum addition quality of Ce(NO3)3 was 0.08 g to 50 ml Fe3+ solution.

Rapid determination of atrazine in environmental water samples by a novel liquid phase microextraction

A novel method was described for the rapid determination of atrazine using dispersive liquid phase microextraction in combination with high performance liquid chromatography （HPLC）. Possible impact parameters such as sample pH, extraction and disperser solvents, salting-out effect, and extraction time were investigated. The experimental results indicated that proposed method possessed an excellent analytical performance, The linear range, detection limit, and precision （R.S.D.） were 0.1- 50 ng mL- 1 （R2 = 0.9955）, 0.601 ng mL- 1 and 6,4%, respectively. The proposed method was validated with the real water samples, and the spiked recoveries were in the range of 69.9-89.8%, respectively. These results indicated that the established method with high enrichment factor, short extraction time was an excellent alternative for the routine analysis of atrazine in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Transient liquid phase bonding of TiC particulate reinforced magnesium metal matrix composite (TiC_p/AZ91D)

Microstructures and mechanical properties of transient liquid phase （TLP） bonded magnesium metal matrix composite （ MMC） joints using copper interlayer have been investigated. With an increase of bonding times from 5 min to 50 min at bonding temperature of 510 ℃ , the average concentration of copper in the bonded zone decreased, the microstructure in the zone changed from Cu, α-Mg and CuMg2 to α-Mg, CuMg2 and TiC, and mechanical properties of the joint increased. The shear strength of the joint bonded at 510 ℃ for 50 min reached 64 MPa due to the metallurgical bonding of the joint and improving its homogeneity of composition and microstructure. It is favorable to increase the bonding time for improving mechanical properties of TLP bonded magnesium MMC joint.

Low Temperature Coating of Anatase Thin Films on Silica Glass Fibers by Liquid Phase Deposition

Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared by adding H3BO3 into （NH4）2TiF6 solution supersaturated with anatase nano-crystalline TiO2 at 40 ℃. The effects of the deposition conditions on the surface morphology, section morphology, thickness of the deposited TiO2 thin films were investigated. The results indicate that the growth rate and particle size of the thin films were controlled by both the deposition conditions and the amount of anatase nano-crystalline TiO2.

Experimental investigation of the normal spectral emissivity and other thermophysical properties of pulse-heated Ni-Ti and Au-Ni alloys into the liquid phase

In a previous paper it was shown that the normal spectral emissivity at 684.5 nm of a binary alloy can be lower than that of the pure constituent components. For the actual probes it was found that the observed values of normal spectral emissivity of the alloys are in between or higher than those of the pure constituent components. Experiments were conducted on the alloy systems Ni-Ti and Au-Ni. Their emissivity as well as electrical resistivity and enthalpy as a function of temperature is presented.

Preparation of CTS Coatings Containing Calcium and Phosphorus on Titanium Surface by the Cathode Liquid Phase Plasma Technology

Chitosan （CTS） coatings contained calcium （Ca） and phosphorus （P） on titanium （Ti） surface are prepared by the cathode liquid phase plasma technology （CLPT）, in a certain concentration electrolyte solution with selective additions of ammonium dihydrogen phosphate and calcium nitrate. It is indicated that the parameters for a stable discharge are voltage of 400 V, frequency of 100 Hz, duty cycle of 30% based on a large amount of experiment data. The morphology, structure and composition of the coated samples are studied by SEM, FTIR, XRD, XPS. The results demonstrate that the composite coatings are uniform, and some solid particles of inorganic salt containing calcium and phosphorus dispersed on the coatings. CA tests show that the samples treated by the liquid plasma became less hydrophilic. The variation of hydrophilicity on the CLPT treated titanium is attributed to the change of the function groups on the sample surface. Meanwhile, a possible formation mechanism of the composite coatings is discussed.

Relationship between Liquid Phase Content and the Orientation of PMNT Ceramics by TGG Method

The effects of glass flit on the sintering and electric properties of PMN-PT textured ceramics were investigated. The glass frits, including PbO, Bi2O3 and ZnO, were selected since liquid phase sintering lowered the PMN-PT sintering temperature. The piezoelectric properties of PMN-PT ceramics with glass frit addition are strongly dependent on the densification. The addition of glass frits into PMN-PT matrix reduced the sintering temperature to 1 100℃ instead of 1 150 ℃ for samples without glass. The piezoelectric coefficients （d33） of PMN-PT textured ceramics achieved 568 pc/N with 1 wt% excess PbO.