High-order models with a dissipative term for nonlinear and dispersive wave in water of varying depth with an arbitrary sloping bottom are presented in this article. First, the formal derivations to any high order of ...High-order models with a dissipative term for nonlinear and dispersive wave in water of varying depth with an arbitrary sloping bottom are presented in this article. First, the formal derivations to any high order of mu(= h/lambda, depth to deep-water wave length ratio) and epsilon(= a/h, wave amplitude to depth ratio) for velocity potential, particle velocity vector, pressure and the Boussinesq-type equations for surface elevation eta and horizontal velocity vector (U) over right arrow at any given level in water are given. Then, the exact explicit expressions to the fourth order of mu are derived. Finally, the linear solutions of eta, (U) over right arrow, C (phase-celerity) and C-g (group velocity) for a constant water depth are obtained. Compared with the Airy theory, excellent results can be found even for a water depth as large as the wave legnth. The present high-order models are applicable to nonlinear regular and irregular waves in water of any varying depth (from shallow to deep) and bottom slope (from mild to steep).展开更多
The system which consists of a reliable machine, an unreliable machine and a storage buffer with infinite many workpieces has been studied. The existence of a unique positive time-dependent solution of the model corre...The system which consists of a reliable machine, an unreliable machine and a storage buffer with infinite many workpieces has been studied. The existence of a unique positive time-dependent solution of the model corresponding to the system has been obtained by using C 0-semigroup theory of linear operators in functional analysis.展开更多
A complete discrimination system for the fourth order polynomial is given. As an application, we have reduced a （1＋1）-dimensional dispersive long wave equation with general coefficients to an elementary integral fo...A complete discrimination system for the fourth order polynomial is given. As an application, we have reduced a （1＋1）-dimensional dispersive long wave equation with general coefficients to an elementary integral form and obtained its all possible exact travelling wave solutions including rational function type solutions, solitary wave solutions, triangle function type periodic solutions and Jacobian elliptic functions double periodic solutions. This method can be also applied to many other similar problems.展开更多
In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4...In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.展开更多
A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） ...A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.展开更多
Obtaining small carbides is crucial but difficult for high-speed steels.A new approach for refining carbide dimensions in M42 super hard high-speed steel by increasing cooling rate and spheroidizing treatment was prop...Obtaining small carbides is crucial but difficult for high-speed steels.A new approach for refining carbide dimensions in M42 super hard high-speed steel by increasing cooling rate and spheroidizing treatment was proposed.The morphologies and properties of eutectic carbides formed at different cooling rates were investigated by means of scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,electron back-scattered diffraction（EBSD）and differential scanning calorimeter（DSC）.The results show that eutectic carbides change from a lamellar shape into a curved-rod shape as cooling rate increases.Despite different morphologies,the two carbides are both of M2C type with a hexagonal close-packed structure and display a single crystal orientation in one eutectic colony.The morphology of M2C mainly depends on the growing process of eutectic carbides,which is strongly influenced by cooling rate.Compared with lamellar carbides,M2C carbides with curved-rod shapes are less stable,and decompose into M6 C and MC at lower temperatures.They are more inclined to spheroidize during heating,which ultimately and distinguishably refines the carbide dimensions.As small carbides are much easier to dissolve into matrices during austenization,the process described herein improves the supersaturation of alloying elements in martensite,which leads to an increment of hardness in M42 steel.展开更多
This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structures in the (2+1)-dimensional dispersive long-wave equations . Starting from the homogeneous ba...This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structures in the (2+1)-dimensional dispersive long-wave equations . Starting from the homogeneous balance method, we find that the richness of the localized coherent structures of the model is caused by the entrance of two variable-separated arbitrary functions. For some special selections of the arbitrary functions, it is shown that the localized structures of the model may be dromions, lumps, breathers, instantons and ring solitons.展开更多
The chemical compositions,mineralogical characteristics,as well as dissemination of iron-and phosphorus-based minerals were studied for the E’xi oolitic hematite from western Hubei Province in China by using chemical...The chemical compositions,mineralogical characteristics,as well as dissemination of iron-and phosphorus-based minerals were studied for the E’xi oolitic hematite from western Hubei Province in China by using chemical analysis,optical microscope,electron probe micro-analyzer(EPMA)and energy dispersive spectroscopy(EDS).It is found that this kind of oolitic hematite ore contains 47.71%TFe,10.96%SiO_2,as well as 0.874%P,with hematite as the dominant Fe-bearing minerals,and quartz,chamosite,illite and cellophane as main gangue minerals.The microscope examination showed that the ore has an oolitic structure,with some ooids principally formed by a series of concentric layers of hematite collophanite around nucleus that is hematite in the association with collophanite.Based on the EPMA and EDS analysis,it can be known that some ooids are primarily composed of hematite and collophanite.The separation can be achieved through fine grinding for those collophanite laminae with a higher P content.However,the dissemination of two minerals at the interface will result in the difficulty in effective separation.Besides,some ooids are made of chamosite with some nucleus formed of quartz,which is principally finely disseminated with hematite.In view of the close association and dissemination of iron-and phosphorus-based minerals in the ooids,it is found that the process of stage-grindings and stage-separations can be adopted to effectively increase the iron recovery and decrease the P content in the concentrate to some extent.展开更多
By using the strong continuous semigroup theory of linear operators we prove the existence of a unique positive time-dependent solution of the model describing a re-pairable, standby, human & machine system.
By using a mapping approach and a linear variable separation approach, a new family of solitary wave solutions with arbitrary functions for the （2＋1）-dimensional modified dispersive water-wave system （MDWW） is de...By using a mapping approach and a linear variable separation approach, a new family of solitary wave solutions with arbitrary functions for the （2＋1）-dimensional modified dispersive water-wave system （MDWW） is derived. Based on the derived solutions and using some multi-valued functions, we obtain some novel folded localized excitations of the system.展开更多
文摘High-order models with a dissipative term for nonlinear and dispersive wave in water of varying depth with an arbitrary sloping bottom are presented in this article. First, the formal derivations to any high order of mu(= h/lambda, depth to deep-water wave length ratio) and epsilon(= a/h, wave amplitude to depth ratio) for velocity potential, particle velocity vector, pressure and the Boussinesq-type equations for surface elevation eta and horizontal velocity vector (U) over right arrow at any given level in water are given. Then, the exact explicit expressions to the fourth order of mu are derived. Finally, the linear solutions of eta, (U) over right arrow, C (phase-celerity) and C-g (group velocity) for a constant water depth are obtained. Compared with the Airy theory, excellent results can be found even for a water depth as large as the wave legnth. The present high-order models are applicable to nonlinear regular and irregular waves in water of any varying depth (from shallow to deep) and bottom slope (from mild to steep).
基金Natural Science Foundation of Henan Province( 994 0 51 2 0 0 )
文摘The system which consists of a reliable machine, an unreliable machine and a storage buffer with infinite many workpieces has been studied. The existence of a unique positive time-dependent solution of the model corresponding to the system has been obtained by using C 0-semigroup theory of linear operators in functional analysis.
文摘A complete discrimination system for the fourth order polynomial is given. As an application, we have reduced a （1＋1）-dimensional dispersive long wave equation with general coefficients to an elementary integral form and obtained its all possible exact travelling wave solutions including rational function type solutions, solitary wave solutions, triangle function type periodic solutions and Jacobian elliptic functions double periodic solutions. This method can be also applied to many other similar problems.
基金the National Natural Science Foundation of China(Nos.20375035,20527005,20775070)by Zhejiang Provincial Natural Science Foundation of China(Nos.Z404105,Y507252).
文摘In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.
基金supported both by the Natural Science Foundations of Hebei(No.B2008000210)the Scientific Research Foundation of Agricultural University of Hebei.
文摘A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.
基金Item Sponsored by National Natural Science Foundation of China(51301038,51201031,51371050)Industry-Academia-Research Program of Jiangsu Province of China(BY2014127-03)+1 种基金Natural Science Foundation of Jiangsu Province of China(BK20141306)Jiangsu Province Key Laboratory of High-end Structural Materials of China(hsm1404)
文摘Obtaining small carbides is crucial but difficult for high-speed steels.A new approach for refining carbide dimensions in M42 super hard high-speed steel by increasing cooling rate and spheroidizing treatment was proposed.The morphologies and properties of eutectic carbides formed at different cooling rates were investigated by means of scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,electron back-scattered diffraction（EBSD）and differential scanning calorimeter（DSC）.The results show that eutectic carbides change from a lamellar shape into a curved-rod shape as cooling rate increases.Despite different morphologies,the two carbides are both of M2C type with a hexagonal close-packed structure and display a single crystal orientation in one eutectic colony.The morphology of M2C mainly depends on the growing process of eutectic carbides,which is strongly influenced by cooling rate.Compared with lamellar carbides,M2C carbides with curved-rod shapes are less stable,and decompose into M6 C and MC at lower temperatures.They are more inclined to spheroidize during heating,which ultimately and distinguishably refines the carbide dimensions.As small carbides are much easier to dissolve into matrices during austenization,the process described herein improves the supersaturation of alloying elements in martensite,which leads to an increment of hardness in M42 steel.
文摘This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structures in the (2+1)-dimensional dispersive long-wave equations . Starting from the homogeneous balance method, we find that the richness of the localized coherent structures of the model is caused by the entrance of two variable-separated arbitrary functions. For some special selections of the arbitrary functions, it is shown that the localized structures of the model may be dromions, lumps, breathers, instantons and ring solitons.
基金Project(51474161)supported by the National Natural Science Foundation of China
文摘The chemical compositions,mineralogical characteristics,as well as dissemination of iron-and phosphorus-based minerals were studied for the E’xi oolitic hematite from western Hubei Province in China by using chemical analysis,optical microscope,electron probe micro-analyzer(EPMA)and energy dispersive spectroscopy(EDS).It is found that this kind of oolitic hematite ore contains 47.71%TFe,10.96%SiO_2,as well as 0.874%P,with hematite as the dominant Fe-bearing minerals,and quartz,chamosite,illite and cellophane as main gangue minerals.The microscope examination showed that the ore has an oolitic structure,with some ooids principally formed by a series of concentric layers of hematite collophanite around nucleus that is hematite in the association with collophanite.Based on the EPMA and EDS analysis,it can be known that some ooids are primarily composed of hematite and collophanite.The separation can be achieved through fine grinding for those collophanite laminae with a higher P content.However,the dissemination of two minerals at the interface will result in the difficulty in effective separation.Besides,some ooids are made of chamosite with some nucleus formed of quartz,which is principally finely disseminated with hematite.In view of the close association and dissemination of iron-and phosphorus-based minerals in the ooids,it is found that the process of stage-grindings and stage-separations can be adopted to effectively increase the iron recovery and decrease the P content in the concentrate to some extent.
基金This research is supported by the Tianyuan Mathematics Foundation (No. 10226007) and the Science Foundation of Xinjiang University
文摘By using the strong continuous semigroup theory of linear operators we prove the existence of a unique positive time-dependent solution of the model describing a re-pairable, standby, human & machine system.
基金Project supported by the Natural Science Foundation of Zhejiang Province, China (Grant Nos. Y6100257 and Y6110140)
文摘By using a mapping approach and a linear variable separation approach, a new family of solitary wave solutions with arbitrary functions for the （2＋1）-dimensional modified dispersive water-wave system （MDWW） is derived. Based on the derived solutions and using some multi-valued functions, we obtain some novel folded localized excitations of the system.
