Effect of two-step solid solution on microstructure andδphase precipitation of Inconel 718 alloy

Inconel 718 is the most popular nickel-based superalloy and is extensively used in aerospace,automotive,and energy indus-tries owing to its extraordinary thermomechanical properties.The effects of different two-step solid solution treatments on microstructure andδphase precipitation of Inconel 718 alloy were studied,and the transformation mechanism fromγ″metastable phase toδphase was clarified.The precipitates were statistically analyzed by X-ray diffractometry.The results show that theδphase content firstly increased,and then decreased with the temperature of the second-step solid solution.The changes in microstructure andδphase were studied by scanning electron microscopy and transmission electron microscopy.An intragranularδphase formed in Inconel 718 alloy at the second-[100]_(δ)[011]γ step solid solution temperature of 925℃,and its orientation relationship withγmatrix was determined as//and(010)_(δ)//(111)γ.Furthermore,the Vickers hardness of different heat treatment samples was measured,and the sample treated by second-step solid solution at 1010℃ reached the maximum hardness of HV 446.84.

Solid state recycling of Mg-Gd-Y-Zn-Zr alloy chips by isothermal sintering and equal channel angular pressing

The Mg-7Gd-4Y-2Zn-0.5Zr alloy chips were successfully recycled through isothermal sintering and equal channel angular pressing(ECAP).The mechanical properties and microstructure evolution of samples during the recycling process were studied in detail.The eutectic phases in the as-cast alloy transform into long period-stacking ordered(LPSO)phases after homogenization,which can improve the plasticity of the material.After isothermal sintering,the density of the sample is lower than that of the homogenized sample,and oxide films are formed adjacent to the bonding interface of the metal chips.Hence,the plasticity of the sintered sample is poor.Dense samples are fabricated after ECAP.Although the grains are not refined compared to the sintered sample,the microstructure becomes more uniform due to recrystallization.Fiber interdendritic LPSO phase and kinked 14H-LPSO phase are formed in the alloy due to the shear deformation during the ECAP process,which improves the strength and plasticity of the sample significantly.Furthermore,the basal texture is weakened due to the Bc route of the ECAP process,which can increase the Schmid factor of the basal slip system and improve the elongation of the sample.After 2 ECAP passes,the fully densified recycled billet shows superior mechanical properties with an ultimate tensile strength of 307.1 MPa and elongation of 11.1%.

Determination of Eleutheroside B and E in Acanthopanax Preparations by High-P erformance Liquid Chromatography with Solid-Phase Extraction

Aim An HPLC method for analyzing eleutheroside B (ELU B) and eleutheroside E(ELU E) , two of the main active substances of Acanthopanax preparations were studied. Methods Thesamples were analyzed on a kromasil ODS column with water-acetonitrile as a gradient mobile phase.The flow rate was 0.8 mL·min^(-1) and detecting wavelengths were 206 nm for ELU B, 220 nm for ELUE, solid phase extraction (SPE) and internal standard-salicin were selected. Results The recoveriesof Acanthopanax tablets and injection were 90.4% - 96.8% and 96.4% - 99.8% for ELU B, 87.7% -93.3%and 95.7% - 98.5% for ELU E, respectively. The linear ranges were 4.45 - 22.25 μg· mL^(-1) (r =0.999 8) and 5.11 - 25.55 μg·mL^(-1) ( r = 0.999 7) respectively. Conclusion This method can savethe time for cleaning the chromatographic system and improve sensitivity for Acanthopanaxpreparations , thus providing a way to evaluate the quality of Acanthopanax preparations.

Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that the unsaturated complex of Cu(II) and benzoic acid (1:1) has strong catalytic effect on the luminol-H2O2 chemiluminescence reaction. The calibration graph is linear over the range of 0.025 ~ 60 g/mL of benzoic acid, with a relative standard deviation of less than 3.0 %, and the detection limit is 0.01礸穖L-1. The proposed method was applied to the determination of benzoic acid content in different pharmaceutical formulations.

Synthesis and Solid Phase Extraction Performance Study of NNAL-specific Molecularly Imprinted Polymers Using Dummy Templates

Dummy molecularly imprinted polymers （DMIPs） for 4-（methylnitrosamino）-1-（3-pyridyl）-1-butanol （NNAL） were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-（acetymethylamino）-1-（3-pyridyl）-butanol, 4- （methylamino）-1-（3-pyridyl）-1-butanol, and 1-（3-pyridyl）-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy （XPS） and Fourier transform infrared spectroscopy （FT-IR）. Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-（acetymethylamino）-1-（3-pyridyl）-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction （DMISPE） was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.

Reaction Process of Chromium Slag Reduced by Industrial Waste in Solid Phase

M, a particular industrial waste, was selected to detoxify chromium slag at a high temperature. The carbon remaining in M reduced Cr （ Ⅳ ） of Na2 CrO4 borne in the chromium slag to Cr （ Ⅲ ） in the solid phase reaction, and its thermodynamics and kinetics were studied. The reduction process of Na2CrO4 by carbon produced CO, whiCh＇was endothermic. Under the experimental condition, the apparent activation energy was 4. 41 kJ·mol^-1 , the＇apparent order of reaction for Na2 CrO4 was equal to one, and the partial pressure of CO was only 0.22 Pa at 1 330℃.

Determination of resveratrol in red wine by solid phase extraction-flow injection chemiluminescence method

A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO4 and HCHO in sulfuric acid medium. Analytes were pre-concentrated on solid sorbents （C18 solid-phase extraction cartridges）. Under the optimum conditions, the proposed method allows the measurement of resveratrol over the range of 1.32 × 10^-8 to 1.32 × 10^-5 mol/L with a detection limit of 3.30 ×10^-9 mol/L, and the relative standard deviation for 1.32 ×10^-5 mol/L resveratrol （n = 11） is 3.8%. This method has been successfully applied for the determination of the resveratrol in red wine. Furthermore, the possible reaction mechanism was also discussed.

Influences of solid particles on the formation of the third phase crud during solvent extraction

The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction, if the pH value was greater than 2.30, the number of solid particles in the mother solution increased, in which case the possibility of forming the third phase crud could also increase, and the interface tension value might grow in pace with the quantity of the third phase crud.

Solid Phase Extraction Chemiluminescence Determination of Methamidaphos on Vegetables

The determination of the methamidaphos pesticide residue on vegetables with a simple solid phase extract（SPE） flow injection（FI） -chemiluminescence（CL） method is described. The method is based on the enhancing effect of methamidaphos on the CL reaction of luminol with hydrogen peroxide in an alkaline solution. Under the optimal conditions, the CL intensity is linear to the methamidaphos mass concentration in a range of 0. 2-13μg/mL （ r= 0. 9992）. The detection limit（3σ） is 0. 047μg/mL. The relative standard deviations for the analysis of three samples are 1.8%, 2.5% and 3.7% （ n = 5 ）, respectively. The recovery is in a range of 90%-109% by the method. In this work, this method was successfully applied to the determination of the methamidaphos residue on some vegetable samples.

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.

Determination of volatile organic compounds in river water by solid phase extraction and gas chromatography

A simple, rapid, and reproducible method is described employing solid phase extraction(SPE) using dichloromethane followed by gas chromatography(GC) with flame ionization detection(FID) for determination of volatile organic compound(VOC) from the Buriganga River water of Bangladesh. The method was applied to detect the benzene, toluene, ethylbenzene, xylene and cumene(BTEXC) in the sample collected from the surface or 15 cm depth of water. Two hundred ml of n hexane pretreated and filtered water samples were applied directly to a C 18 SPE column. BTEXC were extracted with dichloromethane and average concentrations were obtained as 0 104 to 0 372 μg/ml. The highest concentration of benzene was found as 0 372 μg/ml with a relative standard deviation(RSD) of 6 2%, and cumene was not detected. Factors influencing SPE e.g., adsorbent types, sample load volume, eluting solvent, headspace and temperatures, were investigated. A cartridge containing a C 18 adsorbent and using dichloromethane gave better performance for extraction of BTEXC from water. Average recoveries exceeding 90% could be achieved for cumene at 4℃ with a 2 7% RSD.

A novel surface molecularly imprinted polymer as the solid-phase extraction adsorbent for the selective determination of ampicillin sodium in milk and blood samples

Surface molecularly imprinted polymers （SMIPs） for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support. The physical and morphological characteristics of the polymers were investigated by scanning electron microscope （SEM）, Fourier transform infrared spectroscopy （FT-IR）, thermogravimetric analysis （TGA）, elemental analysis and nitrogen adsorption-desorption test. The obtained results showed that the SMIPs displayed great adsorption capacity （13.5 lag/mg）, high recognition ability （the imprinted factor is 3.2） and good binding kinetics for ampicillin sodium. Finally, as solid phase extraction adsorbents, the SMIPs coupled with HPLC method were validated and applied for the enrichment, purification and determination of anapicillin sodium in real milk and blood samples. The averages of spiked accuracy ranged from 92.1% to 107.6%. The relative standard deviations of intra- and inter-day precisions were less than 4.6%. This study provides a new and promising method for enriching, extracting and determining ampicillin sodium in complex biological samples.

Determination of urinary 8-hydroxy-2′-deoxyguanosine by capillary electrophoresis with molecularly imprinted monolith in-tube solid phase microextraction

Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with conv...

Analysis of α, β, γ-hexachlorocyclohexanes in water by novel activated carbon fiber-solid phase microextraction coupled with gas chromatography—mass spectrometry

A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water.

Al-incorporation into Li7La3Zr2O12 solid electrolyte keeping stabilized cubic phase for all-solid-state Li batteries

We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 （LLZO）. A direct incorporation of AI is first promoted in a Li-insufficient garnet solid electrolyte during the calcination process of 850 ℃ and then the cubic phase of LLZO is obtained after successive annealing step of 1000 ℃. Comparing to pristine LLZO, AI incorporated LLZO shows less formation of Li_2CO_3, keeping crystallographic and physicochemical properties. This AI incorporation im- proves both the ionic conductivity and interfacial resistance to poisoning procedure.

Development trend and prospect of solid phase extraction technology

Solid phase extraction is widely used in sample pretreatment,concentration and analysis processes due to high selectivity and suitability for low concentration sample system.In this review,we systematically summarized and discussed the development trends of solid phase extraction by bibliometrics method.By analyzing papers output scale,the research and development direction of solid phase extraction technology is prospected.We also give an overview on current strategies of novel solid phase extraction from the separation medium and separation technology.The paper aims to describe the global research profile and the development trends of solid phase extraction,to help researchers to accurately grasp the research trend and to provide support for scientific research institutions to formulate scientific policies and strategic plans.Furthermore,the prospect of the development and application of solid phase extraction is also discussed.

FORMATION OF MANGANESE SILICIDE THIN FILMS BY SOLID PHASE REACTION

Manganese silicide MnSi_(2-x) thin films have been prepared on n-type siliconsubstrates through solid phase reaction. The heterostructures were analyzed by X-ray diffraction,Rutherford backscattering spectroscopy, Fourier transform infrared transmittance spectroscopy andthe four-point probe technique. The results show that two manganese silicides have been formedsequentially via the reaction of thin layer Mn with Si substrate at different irradiation annealingstages, i.e., MnSi at 450 deg C and MnSi_(1.73) at 550 deg C. MnSi_(1.73) phase exhibits preferredgrowth after irradiation with infrared. In situ four-point probe measurements of sheet resistanceduring infrared irradiation annealing show that nucleation of MnSi and phase transformation of MnSito MaSi_(1.73) occur at 410 deg C and 530 deg C, respectively; the MnSi phase shows metallicbehavior, while MnSi_(1.73) exhibits semiconducting behavior. Characteristic phonon bands ofMnSi_(2-x) silicides, which can be used for phase identification along with conventional XRDtechniques, have been observed by FTIR spectroscopy.

Determination of Aromatic Components of Rosa davurica Pall. by Headspace Solid Phase Microextraction Combined with GC-MS

[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.

Characterization of volatiles Tribolium castaneum(H.)in flour using solid phase microextraction–gas chromatography mass spectrometry(SPME–GCMS)

The objective of this study was to identify volatile organic compounds(VOCs)from flour,Tribolium castaneum(Herbst)and flour infested by T.castaneum separately,to confirm the difference of healthy flour and flour infested by T.castaneum and to explore the new technique to diagnose stored flour’s quality by its VOCs change.Headspace-solid phase microextraction(HS-SPME)coupled with gas chromatography(GC)and gas chromatography–mass spectrometry(GC–MS)were used to detect the VOCs of three different samples.Totally,71 different compounds were identified in flour,T.castaneum and T.castaneum infested flour.Therefore,27 VOCs were identified from flour alone,32 VOCs from T.castaneum and 39 VOCs from T.castaneum infested flour.The compound 2-ethyl-2,5-cyclohexadiene-1,4-dione is only found in T.castaneum infested flour.This suggests that 2-ethyl-2,5-cyclohexadiene-1,4-dione can be a useful VOC for detecting T.castaneum in flour.

Acting mechanism of F,K,and Na in the solid phase sintering reaction of the Baiyunebo iron ore

The effect of F,K,and Na on the solid phase reaction of the Baiyunebo iron ore was investigated by differential thermal analysis （DTA） and X-ray diffraction（XRD）.It has been identified that alkaline elements K and Na in the Baiyunebo ore instigate the formation of low melting point compounds Na2SiO3 and Na2O·Fe2O3 and the generation of molten state in the solid phase sintering.Element F in the Baiyunebo ore facilitates the formation of cuspidine compound 3CaO·2SiO2·CaF2 in the solid phase reaction.The cuspidine compound is kept in solid as one of the final products through the entire sintering process due to its high melting point.In the sintering process,CaF2and SiO2 react with CaO first and form 3CaO·2SiO2·CaF2 and 3CaO·2SiO2,so the formation of ferrites,Na2O·Fe2O3,and 2CaO·Fe2O3 is inhibited.