As-cast and heat-treated 400-18 ductile iron （DI） grade was obtained in different foundry conditions, as metallic charge, Mg-treatment alloy and inoculation. It was found that the Pearlitic Influence Factor （P） an...As-cast and heat-treated 400-18 ductile iron （DI） grade was obtained in different foundry conditions, as metallic charge, Mg-treatment alloy and inoculation. It was found that the Pearlitic Influence Factor （P） and Anti- nodulizing Complex Factor （K1） have an important influence on property of DI, depending on the Mn and P level, the metallurgical quality of iron melt, rare earth （RE） and inoculation. It was also found that the influence of Mn is depended on the phosphorus and residual elements level in ductile iron. Less than 0.03%P and 0.2%Mn and P〈2.0 are the basic conditions to obtain as-cast ferritic structure. At the same lower level of Mn and P, the increasing of residual elements （P〉2.0） determines presence of pearlite in as-cast structure, while ferrite structure is obtained after a short annealing heat treatment. Lower level of phosphorus （P〈0.025%） and residual elements （Px〈2.0） allow to use relative high Mn content （0.32%-0.38%）, in condition of ferritic structure, including in as-cast state. High P （0.04%- 0.045%） and Mn （0.25%-0.35%） content stabilized peadite, especially at lower level of residual elements （P 〈2.0）. Antinodulizing action of elements was counteracted up to K1=2.0 level, by RE included in Mg-treatment alloy, which are beneficial for K1〈1.2 and compulsory for K1〉1.2. Si has a significant influence on the mechanical properties of heat treated ductile irons： an important decreasing of elongation level and a moderate increasing of yield and tensile strength and their ratio in 150-170 HB typical hardness field. A typical final chemical composition for as-cast 400-18 ductile iron could include 3.5%-3.7%C, 2.4%-2.5%Si, max.0.18%Mn, max.0.025%P, max.0.01%S, 0.04%-0.05%Mg for Px〈1.5 and K1〈1.1. High purity pig iron, RE-bearing FeSiMg and powerful inoculant are also recommended.展开更多
In this study,the stagnation point transport of second grade fluid with linear stretching under the effects of variable thermal conductivity is considered.Induced magnetic field impact is also incorporated.The nonline...In this study,the stagnation point transport of second grade fluid with linear stretching under the effects of variable thermal conductivity is considered.Induced magnetic field impact is also incorporated.The nonlinear set of particle differential equations is converted into set of ordinary differential equations through appropriate transformation.The resulting equations are then resolved by optimal homotopy analysis method.The effect of pertinent parameters of interest on skin friction coefficient,temperature,induced magnetic field,velocity and local Nusselt number is inspected by generating appropriate plots.For numerical results,the built-in bvp4 c technique in computational software MATLAB is used for the convergence and residual errors of obtained series solution.It is perceived that the induced magnetic field is intensified by increasing β.It can also be observed that skin friction coefficient enhances with increasing value of magnetic parameter depending on the stretching ratio a/c.For the validness of the obtained results,a comparison has been made and an excellent agreement of current study with existing literature is found.展开更多
The paper develops and examines the complete solutions for the elastic field induced by the point load vector in a general functionally graded material(FGM)model with transverse isotropy.The FGMs are approximated with...The paper develops and examines the complete solutions for the elastic field induced by the point load vector in a general functionally graded material(FGM)model with transverse isotropy.The FGMs are approximated with n-layered materials.Each of the n-layered materials is homogeneous and transversely isotropic.The complete solutions of the displacement and stress fields are explicitly expressed in the forms of fifteen classical Hankel transform integrals with ten kernel functions.The ten kernel functions are explicitly expressed in the forms of backward transfer matrices and have clear mathematical properties.The singular terms of the complete solutions are analytically isolated and expressed in exact closed forms in terms of elementary harmonic functions.Numerical results show that the computation of the complete solutions can be achieved with high accuracy and efficiency.展开更多
A computer model for studying the mechanical properties of point - bonded nonwovens is established. The simulation tensile curve of a nonwoven fabric may be obtained based on relaxation procedure when the mechanical p...A computer model for studying the mechanical properties of point - bonded nonwovens is established. The simulation tensile curve of a nonwoven fabric may be obtained based on relaxation procedure when the mechanical properties of fibers, the arrangement of bond points in the fibrous web and specimen size are inputted into the computer. Relaxation method and relevant algorithms of computer simulation are described in detail. The validity of the model is also demonstrated.展开更多
By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we...By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points.展开更多
The accurate evaluation of a course determines the quality of learning and is the basis for evaluating the students' academic achievements. This paper, on the theoretical basis of grade point, builds a dynamic str...The accurate evaluation of a course determines the quality of learning and is the basis for evaluating the students' academic achievements. This paper, on the theoretical basis of grade point, builds a dynamic stratified GPA (Grade Point Average) evaluation model for the course Automotive Electrical System Diagnosis, focuses on the whole process assessment and aims to stimulate the enthusiasm of learning to meet the demands of the training of social skilled talents.展开更多
In this paper, first we introduce notions of (α, Ψ)-contractive and (α)-admissible for a pair of map and prove a coupled coincidence point theorem for compatible mappings using these notions. Our work extends and g...In this paper, first we introduce notions of (α, Ψ)-contractive and (α)-admissible for a pair of map and prove a coupled coincidence point theorem for compatible mappings using these notions. Our work extends and generalizes the results of Mursaleen et al. [1]. At the end, we will provide an example in support of our result.展开更多
<strong>Objective:</strong> The purpose of this work was to determine the epidemiological, clinical and evolutionary aspects of the pulmonary embolism of the young person in the cardiology department of th...<strong>Objective:</strong> The purpose of this work was to determine the epidemiological, clinical and evolutionary aspects of the pulmonary embolism of the young person in the cardiology department of the University Hospital Center (CHU) Point G in Bamako-Mali. <strong>Methodology:</strong> This was an analytical study from January 01, 2018 to December 31, 2018 in the CHU Point G cardiology department, including all patients hospitalized during this period. <strong>Results:</strong> Of 1379 hospitalized patients, 19 patients were concerned by pulmonary embolism of the young person. The prevalence of pulmonary embolism of the young person was 1.37%. The most affected age group was 21 - 30 (47.4%) of patients. The predominance was female (89.47%) with a gender ratio of 0.11 in favour of women. The average age in the series was 29.79 years with extremes of 16 years and 40 years. Factors predisposing to pulmonary embolism were dominated by peri partum, cardiomyopathy and obesity with 47.3%, 31.57% and 21.1%, respectively. The dominant signs were chest pain and dyspnea in 94.7% and 89.5% of cases respectively. Pulmonary embolism was unlikely in 60.52% according to the Geneva and Wells score simplified. At the thoracic angioscanner, the embolism was bilateral in 52.6% of cases and distal in 36.8% of patients;in 10 patients who performed cardiac ultrasound, pulmonary arterial hypertension (70%), dilation of the right ventricle (20%) and left ventricular dilation (40%). Hyper leucocytosis (47.4%), anemia and low prothrombin rate (TP) (22.2%) were the most found biological abnormalities. More than 2/3 (68.5%) our patients had an intermediate mortality risk according to the PESI (Pulmonary Embolism Severity Index) score. The average hospital stay was 10 days. Hospital mortality was 10.5%. <strong>Conclusion:</strong> The pulmonary embolism of the young person is a frequent, serious and multifactorial pathology and the female sex is most affected especially during peri partum periods, hence the need for preventive measures. Clinical signs are not specific and based on the assessment of clinical probability. Pulmonary angioscanner remains the confirmation review in our context.展开更多
We apply a Cross-Correlation （CC） method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We...We apply a Cross-Correlation （CC） method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We find that the CC method is a powerful tool to examine the WMAP foreground residuals which can be further cleaned accord- ingly. Evident foreground signals are found in the WMAP foreground cleaned maps and the Tegmark cleaned map. In this process 101 point sources are detected, and 26 of them are new sources additional to the originally listed WMAP 208 sources. We estimate the flux of these new sources and verify them by another method. As a result, a revised mask file based on the WMAP first year data is produced by including these new sources.展开更多
CAS 132-2006 formulation background and work courses
Flat panel display technology is maturing alongside the development of science and technology. The prices of flat panel display TV sets are becoming lower ... CAS 132-2006 formulation background and work courses
Flat panel display technology is maturing alongside the development of science and technology. The prices of flat panel display TV sets are becoming lower and lower. Flat panel display TV sets have begun entering the mainstream and are now the first choice of some consumers when making new TV purchases.Display TV Set Installation Service Point Explanation and AnalysisRepair, Retreat and Change Duty Stipulations. Peculiar use conditions, usage environments, and the practical circumstances of user consumption service requirements, etc., were also taken into account on the basis of extensive investigation, testing, and verification.……展开更多
功能点分析法是一种使用非常广泛的软件规模估算方法。主要针对IFPUG(International Function PointUser Group)提出的功能点分析法在划分功能组件复杂度等级时所存在的不连续性问题,结合模糊理论和插值方法,提出了模糊-插值功能点分析...功能点分析法是一种使用非常广泛的软件规模估算方法。主要针对IFPUG(International Function PointUser Group)提出的功能点分析法在划分功能组件复杂度等级时所存在的不连续性问题,结合模糊理论和插值方法,提出了模糊-插值功能点分析法,解决了复杂度等级划分中出现的不连续、不精确等缺点和问题。实例证明,新方法不仅能更准确地估算出功能点数量,而且具有很强的实际可操作性。展开更多
文摘As-cast and heat-treated 400-18 ductile iron （DI） grade was obtained in different foundry conditions, as metallic charge, Mg-treatment alloy and inoculation. It was found that the Pearlitic Influence Factor （P） and Anti- nodulizing Complex Factor （K1） have an important influence on property of DI, depending on the Mn and P level, the metallurgical quality of iron melt, rare earth （RE） and inoculation. It was also found that the influence of Mn is depended on the phosphorus and residual elements level in ductile iron. Less than 0.03%P and 0.2%Mn and P〈2.0 are the basic conditions to obtain as-cast ferritic structure. At the same lower level of Mn and P, the increasing of residual elements （P〉2.0） determines presence of pearlite in as-cast structure, while ferrite structure is obtained after a short annealing heat treatment. Lower level of phosphorus （P〈0.025%） and residual elements （Px〈2.0） allow to use relative high Mn content （0.32%-0.38%）, in condition of ferritic structure, including in as-cast state. High P （0.04%- 0.045%） and Mn （0.25%-0.35%） content stabilized peadite, especially at lower level of residual elements （P 〈2.0）. Antinodulizing action of elements was counteracted up to K1=2.0 level, by RE included in Mg-treatment alloy, which are beneficial for K1〈1.2 and compulsory for K1〉1.2. Si has a significant influence on the mechanical properties of heat treated ductile irons： an important decreasing of elongation level and a moderate increasing of yield and tensile strength and their ratio in 150-170 HB typical hardness field. A typical final chemical composition for as-cast 400-18 ductile iron could include 3.5%-3.7%C, 2.4%-2.5%Si, max.0.18%Mn, max.0.025%P, max.0.01%S, 0.04%-0.05%Mg for Px〈1.5 and K1〈1.1. High purity pig iron, RE-bearing FeSiMg and powerful inoculant are also recommended.
文摘In this study,the stagnation point transport of second grade fluid with linear stretching under the effects of variable thermal conductivity is considered.Induced magnetic field impact is also incorporated.The nonlinear set of particle differential equations is converted into set of ordinary differential equations through appropriate transformation.The resulting equations are then resolved by optimal homotopy analysis method.The effect of pertinent parameters of interest on skin friction coefficient,temperature,induced magnetic field,velocity and local Nusselt number is inspected by generating appropriate plots.For numerical results,the built-in bvp4 c technique in computational software MATLAB is used for the convergence and residual errors of obtained series solution.It is perceived that the induced magnetic field is intensified by increasing β.It can also be observed that skin friction coefficient enhances with increasing value of magnetic parameter depending on the stretching ratio a/c.For the validness of the obtained results,a comparison has been made and an excellent agreement of current study with existing literature is found.
基金Project supported by the National Natural Science Foundation of China(No.42207182)the Research Grants Council of the Hong Kong Special Administrative Region Government of China(Nos.HKU 17207518 and R5037-18)。
文摘The paper develops and examines the complete solutions for the elastic field induced by the point load vector in a general functionally graded material(FGM)model with transverse isotropy.The FGMs are approximated with n-layered materials.Each of the n-layered materials is homogeneous and transversely isotropic.The complete solutions of the displacement and stress fields are explicitly expressed in the forms of fifteen classical Hankel transform integrals with ten kernel functions.The ten kernel functions are explicitly expressed in the forms of backward transfer matrices and have clear mathematical properties.The singular terms of the complete solutions are analytically isolated and expressed in exact closed forms in terms of elementary harmonic functions.Numerical results show that the computation of the complete solutions can be achieved with high accuracy and efficiency.
文摘A computer model for studying the mechanical properties of point - bonded nonwovens is established. The simulation tensile curve of a nonwoven fabric may be obtained based on relaxation procedure when the mechanical properties of fibers, the arrangement of bond points in the fibrous web and specimen size are inputted into the computer. Relaxation method and relevant algorithms of computer simulation are described in detail. The validity of the model is also demonstrated.
文摘By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points.
文摘The accurate evaluation of a course determines the quality of learning and is the basis for evaluating the students' academic achievements. This paper, on the theoretical basis of grade point, builds a dynamic stratified GPA (Grade Point Average) evaluation model for the course Automotive Electrical System Diagnosis, focuses on the whole process assessment and aims to stimulate the enthusiasm of learning to meet the demands of the training of social skilled talents.
文摘In this paper, first we introduce notions of (α, Ψ)-contractive and (α)-admissible for a pair of map and prove a coupled coincidence point theorem for compatible mappings using these notions. Our work extends and generalizes the results of Mursaleen et al. [1]. At the end, we will provide an example in support of our result.
文摘<strong>Objective:</strong> The purpose of this work was to determine the epidemiological, clinical and evolutionary aspects of the pulmonary embolism of the young person in the cardiology department of the University Hospital Center (CHU) Point G in Bamako-Mali. <strong>Methodology:</strong> This was an analytical study from January 01, 2018 to December 31, 2018 in the CHU Point G cardiology department, including all patients hospitalized during this period. <strong>Results:</strong> Of 1379 hospitalized patients, 19 patients were concerned by pulmonary embolism of the young person. The prevalence of pulmonary embolism of the young person was 1.37%. The most affected age group was 21 - 30 (47.4%) of patients. The predominance was female (89.47%) with a gender ratio of 0.11 in favour of women. The average age in the series was 29.79 years with extremes of 16 years and 40 years. Factors predisposing to pulmonary embolism were dominated by peri partum, cardiomyopathy and obesity with 47.3%, 31.57% and 21.1%, respectively. The dominant signs were chest pain and dyspnea in 94.7% and 89.5% of cases respectively. Pulmonary embolism was unlikely in 60.52% according to the Geneva and Wells score simplified. At the thoracic angioscanner, the embolism was bilateral in 52.6% of cases and distal in 36.8% of patients;in 10 patients who performed cardiac ultrasound, pulmonary arterial hypertension (70%), dilation of the right ventricle (20%) and left ventricular dilation (40%). Hyper leucocytosis (47.4%), anemia and low prothrombin rate (TP) (22.2%) were the most found biological abnormalities. More than 2/3 (68.5%) our patients had an intermediate mortality risk according to the PESI (Pulmonary Embolism Severity Index) score. The average hospital stay was 10 days. Hospital mortality was 10.5%. <strong>Conclusion:</strong> The pulmonary embolism of the young person is a frequent, serious and multifactorial pathology and the female sex is most affected especially during peri partum periods, hence the need for preventive measures. Clinical signs are not specific and based on the assessment of clinical probability. Pulmonary angioscanner remains the confirmation review in our context.
基金Supported by the National Natural Science Foundation of China.
文摘We apply a Cross-Correlation （CC） method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We find that the CC method is a powerful tool to examine the WMAP foreground residuals which can be further cleaned accord- ingly. Evident foreground signals are found in the WMAP foreground cleaned maps and the Tegmark cleaned map. In this process 101 point sources are detected, and 26 of them are new sources additional to the originally listed WMAP 208 sources. We estimate the flux of these new sources and verify them by another method. As a result, a revised mask file based on the WMAP first year data is produced by including these new sources.
文摘 CAS 132-2006 formulation background and work courses
Flat panel display technology is maturing alongside the development of science and technology. The prices of flat panel display TV sets are becoming lower and lower. Flat panel display TV sets have begun entering the mainstream and are now the first choice of some consumers when making new TV purchases.Display TV Set Installation Service Point Explanation and AnalysisRepair, Retreat and Change Duty Stipulations. Peculiar use conditions, usage environments, and the practical circumstances of user consumption service requirements, etc., were also taken into account on the basis of extensive investigation, testing, and verification.……
文摘功能点分析法是一种使用非常广泛的软件规模估算方法。主要针对IFPUG(International Function PointUser Group)提出的功能点分析法在划分功能组件复杂度等级时所存在的不连续性问题,结合模糊理论和插值方法,提出了模糊-插值功能点分析法,解决了复杂度等级划分中出现的不连续、不精确等缺点和问题。实例证明,新方法不仅能更准确地估算出功能点数量,而且具有很强的实际可操作性。
