Influence of hydrogen attack on mechanical and fatigue properties of 1020, 15CrMo and 2.25Cr-1Mo steels has been studied, which were exposed to gaseous hydrogen at pressure of 18MPa and 300-480℃ for up to 480h. The r...Influence of hydrogen attack on mechanical and fatigue properties of 1020, 15CrMo and 2.25Cr-1Mo steels has been studied, which were exposed to gaseous hydrogen at pressure of 18MPa and 300-480℃ for up to 480h. The results of fatigue test showed that hydrogen attack (HA) resulted in an obvious change in fatigue properties of 1020 and 15CrMo steels, however, 2.25Cr-1Mo steel showed a lower susceptibility to hydrogen attack due to the addition of Cr and Mo. Fatigue crack behaviour for 1020 steel is attributed to hydrogen attack damage and the crack closure induced by the rough cracking surface, which lead to a valley on △Kth~HA% plot. The change in the fatigue behaviour of 15CrMo steel is possibly caused by severe surface decarburization.展开更多
A pulsed discharge plasma(PDP) reactor with net anode and net cathode was established for investigating the pyrene degradation in soil under different pulse peak voltage,air flow rate,pyrene content in soil,initial ...A pulsed discharge plasma(PDP) reactor with net anode and net cathode was established for investigating the pyrene degradation in soil under different pulse peak voltage,air flow rate,pyrene content in soil,initial p H value and initial water content of the soil.Pyrene oxidation within the 60 min discharge time was fitting according to the pseudo-first order equation and the corresponding reaction kinetics constants(k values) were calculated.The obtained results show that pyrene oxidation under all the different reaction conditions obeyed the pseudo-first order equation well.Higher pulsed peak voltage and appropriate air flow rate were in favor of the increase of reaction rate of pyrene oxidation.A higher k value could be achieved in the lower initial pyrene content(the value was 100 mg kg^-1).The k value of pyrene oxidation in the case of p H=4 was 11.2 times higher than the value obtained under the condition of p H=9,while the initial water content of the soil also has a large effect on the oxidation rate of pyrene due to the effect of PDP.展开更多
Reactive dyes are the main dyes in printing and dyeing of cellulosic fibers.Reactive dyes fixation rate is a vital indicator to measure the degree of the covalent bond between cellulose and reactive dyes.However,the d...Reactive dyes are the main dyes in printing and dyeing of cellulosic fibers.Reactive dyes fixation rate is a vital indicator to measure the degree of the covalent bond between cellulose and reactive dyes.However,the determination of the fixation rate is tedious and time-consumptive.Based on the theory of reactive dyes dyeing and application of modern computer color matching technology,the relationship between K/S value and the fixation rate with the reactive dyes on cotton fabric was studied.The feasibility of K/S value instead of the traditional washing method for the determination of reactive dyes fixation rate was proved.In this study,the K/S value of the fabric has an excellent linear relationship to the reactive dyes fixation rate obtained by the washing method.The reactive dyes fixation rate can be obtained through the K/S correction value.展开更多
Dyeing of PET materials by traditional methods presents several problems.Plasma technology has received enormous attention as a solution for the environmental problems related with textile surface modifications,and th...Dyeing of PET materials by traditional methods presents several problems.Plasma technology has received enormous attention as a solution for the environmental problems related with textile surface modifications,and there has been a rapid development and commercialization of plasma technology over the past decade.In this work,the synergistic effect of atmospheric pressure plasma on alkaline etching and deep coloring of dyeing properties on polyethylene terephthalate(PET)fabrics and films was investigated.The topographical changes of the PET surface were investigated by atomic force microscopy(AFM)images,which revealed a smooth surface morphology of the untreated sample whereas a high surface roughness for the plasma and/or alkaline treated samples.The effects of atmospheric pressure plasma on alkaline etching of the structure and properties of PET were investigated by means of differential scanning calorimetry(DSC),the main objective of performing DSC was to investigate the effect of the plasma pre-treatment on the T_g and T_m.Using a tensile strength tester YG065 H and following a standard procedure the maximum force and elongation at maximum force of PET materials was investigated.Oxygen and argon plasma pre-treatment was found to increase the PET fabric weight loss rate.The color strength of PET fabrics was increased by various plasma pre-treatment times.The penetration of plasma and alkaline reactive species deep into the PET structure results in better dyeability and leaves a significant effect on the K/S values of the plasma pre-treated PET.It indicated that plasma pre-treatment has a great synergistic effect with the alkaline treatment of PET.展开更多
The real rectangular tensors arise from the strong ellipticity condition problem in solid mechanics and the entanglement problem in quantum physics. In this paper, we study the singular values/vectors problem of real ...The real rectangular tensors arise from the strong ellipticity condition problem in solid mechanics and the entanglement problem in quantum physics. In this paper, we study the singular values/vectors problem of real nonnegative partially symmetric rectangular tensors. We first introduce the concepts of/k,S-singular values/vectors of real partially symmetric rectangular tensors. Then, based upon the presented properties of lk,S-singular values /vectors, some properties of the related /k'S-spectral radius are discussed. Furthermore, we prove two analogs of Perron-Frobenius theorem and weak Perron-Frobenius theorem for real nonnegative partially symmetric rectangular tensors.展开更多
LaON,LaTiO and LaTiON films are deposited as gate dielectrics by incorporating N or/and Ti into La_2O_3 using the sputtering method to fabricate Ge MOS capacitors,and the electrical properties of the devices are caref...LaON,LaTiO and LaTiON films are deposited as gate dielectrics by incorporating N or/and Ti into La_2O_3 using the sputtering method to fabricate Ge MOS capacitors,and the electrical properties of the devices are carefully examined.LaON/Ge capacitors exhibit the best interface quality,gate leakage property and device reliability,but a smaller k value(14.9).LaTiO/Ge capacitors exhibit a higher k value(22.7),but a deteriorated interface quality,gate leakage property and device reliability.LaTiON/Ge capacitors exhibit the highest k value(24.6),and a relatively better interface quality(3.1×10^(11) eV^(-1)cm^(-2)),gate leakage property(3.6 × 10^(-3) A/cm^2 at V_g = 1V+V_(fb)) and device reliability.Therefore,LaTiON is more suitable for high performance Ge MOS devices as a gate dielectric than LaON and LaTiO materials.展开更多
By the Schauder fixed point theory,this paper establishes the existence of positive solutions to a(k,n k) m-point boundary value problem.We show that there exists a positive constant b such that the problem has at lea...By the Schauder fixed point theory,this paper establishes the existence of positive solutions to a(k,n k) m-point boundary value problem.We show that there exists a positive constant b such that the problem has at least one positive solution when the homogeneous boundary parameter is smaller than b,and no positive solution when this parameter is greater than b.展开更多
By the fxed point index theory, the existence of one, two and three positive solutions to(k, n-k) conjugate boundary value problems is obtained, where n 】 2, 1 ≤ k ≤ n-1, the nonlinear term may be noncontinuous and...By the fxed point index theory, the existence of one, two and three positive solutions to(k, n-k) conjugate boundary value problems is obtained, where n 】 2, 1 ≤ k ≤ n-1, the nonlinear term may be noncontinuous and singular at any point of [0,1]. Our results extend some of the existent results.展开更多
Elastic impedance (EI) inversion has been widely used in industry to estimate kinds of elastic parameters to distinguish lithology or even fluid. However, it is found that conventional three-term elastic impedance f...Elastic impedance (EI) inversion has been widely used in industry to estimate kinds of elastic parameters to distinguish lithology or even fluid. However, it is found that conventional three-term elastic impedance formula is unstable even with slight random noise in seismic data, due to the m-conditioned co- efficient matrix of elastic parameters. We presented two-term Fatti elastic impedance inversion method, which is more robust and accurate than conventional three-term elastic impedance inversion. In our method, density is ignored to increase the robustness of inversion matrix. Besides, P-impedance and S-impedance, which are less sensitive to random noise, are inverted instead of Vp and Vs in conventional three-term elastic impedance. To make the inversion more stable, we defined the range of K value as a con- straint. Synthetic tests claim that this method can obtain promising results with low SNR (signal noise ratio) seismic data. With the application of the method in a 2D line data, we achieved λp, μp and Vp/Vs sections, which matched the drilled well perfectly, indicating the potential of the method in reservoir prediction.展开更多
文摘Influence of hydrogen attack on mechanical and fatigue properties of 1020, 15CrMo and 2.25Cr-1Mo steels has been studied, which were exposed to gaseous hydrogen at pressure of 18MPa and 300-480℃ for up to 480h. The results of fatigue test showed that hydrogen attack (HA) resulted in an obvious change in fatigue properties of 1020 and 15CrMo steels, however, 2.25Cr-1Mo steel showed a lower susceptibility to hydrogen attack due to the addition of Cr and Mo. Fatigue crack behaviour for 1020 steel is attributed to hydrogen attack damage and the crack closure induced by the rough cracking surface, which lead to a valley on △Kth~HA% plot. The change in the fatigue behaviour of 15CrMo steel is possibly caused by severe surface decarburization.
基金Supported by National Natural Science Foundation of China(No.21207052)
文摘A pulsed discharge plasma(PDP) reactor with net anode and net cathode was established for investigating the pyrene degradation in soil under different pulse peak voltage,air flow rate,pyrene content in soil,initial p H value and initial water content of the soil.Pyrene oxidation within the 60 min discharge time was fitting according to the pseudo-first order equation and the corresponding reaction kinetics constants(k values) were calculated.The obtained results show that pyrene oxidation under all the different reaction conditions obeyed the pseudo-first order equation well.Higher pulsed peak voltage and appropriate air flow rate were in favor of the increase of reaction rate of pyrene oxidation.A higher k value could be achieved in the lower initial pyrene content(the value was 100 mg kg^-1).The k value of pyrene oxidation in the case of p H=4 was 11.2 times higher than the value obtained under the condition of p H=9,while the initial water content of the soil also has a large effect on the oxidation rate of pyrene due to the effect of PDP.
文摘Reactive dyes are the main dyes in printing and dyeing of cellulosic fibers.Reactive dyes fixation rate is a vital indicator to measure the degree of the covalent bond between cellulose and reactive dyes.However,the determination of the fixation rate is tedious and time-consumptive.Based on the theory of reactive dyes dyeing and application of modern computer color matching technology,the relationship between K/S value and the fixation rate with the reactive dyes on cotton fabric was studied.The feasibility of K/S value instead of the traditional washing method for the determination of reactive dyes fixation rate was proved.In this study,the K/S value of the fabric has an excellent linear relationship to the reactive dyes fixation rate obtained by the washing method.The reactive dyes fixation rate can be obtained through the K/S correction value.
基金partially supported by the National Natural Science Foundation of China Contract 11375042
文摘Dyeing of PET materials by traditional methods presents several problems.Plasma technology has received enormous attention as a solution for the environmental problems related with textile surface modifications,and there has been a rapid development and commercialization of plasma technology over the past decade.In this work,the synergistic effect of atmospheric pressure plasma on alkaline etching and deep coloring of dyeing properties on polyethylene terephthalate(PET)fabrics and films was investigated.The topographical changes of the PET surface were investigated by atomic force microscopy(AFM)images,which revealed a smooth surface morphology of the untreated sample whereas a high surface roughness for the plasma and/or alkaline treated samples.The effects of atmospheric pressure plasma on alkaline etching of the structure and properties of PET were investigated by means of differential scanning calorimetry(DSC),the main objective of performing DSC was to investigate the effect of the plasma pre-treatment on the T_g and T_m.Using a tensile strength tester YG065 H and following a standard procedure the maximum force and elongation at maximum force of PET materials was investigated.Oxygen and argon plasma pre-treatment was found to increase the PET fabric weight loss rate.The color strength of PET fabrics was increased by various plasma pre-treatment times.The penetration of plasma and alkaline reactive species deep into the PET structure results in better dyeability and leaves a significant effect on the K/S values of the plasma pre-treated PET.It indicated that plasma pre-treatment has a great synergistic effect with the alkaline treatment of PET.
文摘The real rectangular tensors arise from the strong ellipticity condition problem in solid mechanics and the entanglement problem in quantum physics. In this paper, we study the singular values/vectors problem of real nonnegative partially symmetric rectangular tensors. We first introduce the concepts of/k,S-singular values/vectors of real partially symmetric rectangular tensors. Then, based upon the presented properties of lk,S-singular values /vectors, some properties of the related /k'S-spectral radius are discussed. Furthermore, we prove two analogs of Perron-Frobenius theorem and weak Perron-Frobenius theorem for real nonnegative partially symmetric rectangular tensors.
基金supported by the National Natural Science Foundation of China(No.61274112)the Natural Science Foundation of Hubei Province(No.2011CDB165)the Scientific Research Program of Huanggang Normal University(No.2012028803)
文摘LaON,LaTiO and LaTiON films are deposited as gate dielectrics by incorporating N or/and Ti into La_2O_3 using the sputtering method to fabricate Ge MOS capacitors,and the electrical properties of the devices are carefully examined.LaON/Ge capacitors exhibit the best interface quality,gate leakage property and device reliability,but a smaller k value(14.9).LaTiO/Ge capacitors exhibit a higher k value(22.7),but a deteriorated interface quality,gate leakage property and device reliability.LaTiON/Ge capacitors exhibit the highest k value(24.6),and a relatively better interface quality(3.1×10^(11) eV^(-1)cm^(-2)),gate leakage property(3.6 × 10^(-3) A/cm^2 at V_g = 1V+V_(fb)) and device reliability.Therefore,LaTiON is more suitable for high performance Ge MOS devices as a gate dielectric than LaON and LaTiO materials.
文摘By the Schauder fixed point theory,this paper establishes the existence of positive solutions to a(k,n k) m-point boundary value problem.We show that there exists a positive constant b such that the problem has at least one positive solution when the homogeneous boundary parameter is smaller than b,and no positive solution when this parameter is greater than b.
基金supported by the National Natural Science Foundation of China(11171088)the Natural Science Foundation of Hebei Province(A2013208108)the Foundation of Hebei University of Science and Technology(XI2013060)
文摘By the fxed point index theory, the existence of one, two and three positive solutions to(k, n-k) conjugate boundary value problems is obtained, where n 】 2, 1 ≤ k ≤ n-1, the nonlinear term may be noncontinuous and singular at any point of [0,1]. Our results extend some of the existent results.
基金the sponsorship of the National Natural Science Foundation of China (Nos.41004096 and 41230318) for funding this research
文摘Elastic impedance (EI) inversion has been widely used in industry to estimate kinds of elastic parameters to distinguish lithology or even fluid. However, it is found that conventional three-term elastic impedance formula is unstable even with slight random noise in seismic data, due to the m-conditioned co- efficient matrix of elastic parameters. We presented two-term Fatti elastic impedance inversion method, which is more robust and accurate than conventional three-term elastic impedance inversion. In our method, density is ignored to increase the robustness of inversion matrix. Besides, P-impedance and S-impedance, which are less sensitive to random noise, are inverted instead of Vp and Vs in conventional three-term elastic impedance. To make the inversion more stable, we defined the range of K value as a con- straint. Synthetic tests claim that this method can obtain promising results with low SNR (signal noise ratio) seismic data. With the application of the method in a 2D line data, we achieved λp, μp and Vp/Vs sections, which matched the drilled well perfectly, indicating the potential of the method in reservoir prediction.