Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechan...Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechanism of heat generationwas discussed. Fatigue limit of the welded joint was predicted and the fatigue damage was also assessed based ontheevolution of the temperatureand hotspot zone on the specimen surfaceduring fatigue tests. The presented results show that infrared thermography can not onlyquicklypredict the fatigue behavior of the welded joint, but also qualitatively identify the evolution of fatigue damage in real time. It is found that the predicted fatigue limit agrees well with the conventionalS-Nexperimental results. The evolution of the temperatureand hotspot zone on the specimen surface can be an effectivefatigue damage indicatorfor effectiveevaluationof magnesium alloy electron beam welded joint.展开更多
The location of U-turn bays is an important consideration in indirect driveway left-turn treatments.In order to improve the performance of right-turns followed by U-turns(RTUTs),this study evaluates the impacts of t...The location of U-turn bays is an important consideration in indirect driveway left-turn treatments.In order to improve the performance of right-turns followed by U-turns(RTUTs),this study evaluates the impacts of the separation distances between driveway exits and downstream U-turn locations on the safety and operational performance of vehicles making RTUTs.Crash data are investigated at 179 selected roadway segments,and travel time data are measured using video cameras at 29 locations in the state of Florida,USA.Crash rate models and travel time models are developed based on data collected in the field.It is found that the separation distance between driveway exits and downstream U-turn locations significantly impacts the safety and operational performance of vehicles making right turns followed by U-turns.Based on the research results,the minimum and optimal separation distances between driveways and U-turn locations under different roadway conditions are determined to facilitate driver use of RTUTs.The results of this study can be used for future intersection improvement projects in China.展开更多
Migraine is a complex and heterogeneous disorder. Although several genetic models has been proposed including autosomal-dominant/autosomal recessive, sex-linked, sex-limited, mitochondrial, and multi-gene, none of the...Migraine is a complex and heterogeneous disorder. Although several genetic models has been proposed including autosomal-dominant/autosomal recessive, sex-linked, sex-limited, mitochondrial, and multi-gene, none of these models can well-explain the transmission of the disease. We hypothesied that migraine is a sex-conditioned inherited disorder (autosomal dominant in females and autosomal recessive in males). This hypothesis is supported by the evidence such as the locations of genes associated with familial hemiplegic migraine, possibly "typical" migraine as well (dominantly on chromosome 19p, lq, and 2q), male:female ratio of prevalence (1:2-1:4), the mostly youth-onset, the provocation by the contraceptives, the induction by menstruation, and the self-limitation after menopause. Female sex-hormones appear to be the key contributor to a higher prevalence of migraine in female. Socio-environmental factors may also play an important role.展开更多
Joining of dissimilar metals will offer many advantages in transportation sectors such as fuel consumption,weightreduction and emission reduction.However,joining of aluminium(Al)alloys with magnesium(Mg)alloys by fusi...Joining of dissimilar metals will offer many advantages in transportation sectors such as fuel consumption,weightreduction and emission reduction.However,joining of aluminium(Al)alloys with magnesium(Mg)alloys by fusion welding processis very complicated.Friction stir welding(FSW)is a feasible method to join these two dissimilar alloys.Mixing these two metalstogether in stir zone(SZ)leads to poor corrosion resistance.In this investigation,an attempt has been made to understand thecorrosion resistance of SZ of FSWed dissimilar joints of AA6061Al alloy and AZ31B Mg alloy.Potentiodynamic polarization testwas conducted by varying chloride ion concentration,pH value of the NaCl solution and exposure time.The corroded surfaces wereanalyzed using optical microscopy,scanning electron microscopy and XRD techniques.Of these three factors investigated,exposuretime is found to be the most significant factor to influence the corrosion behaviour of SZ of friction stir welded dissimilar joints ofAl/Mg alloys.展开更多
AIM: To look for the evidence of human papilloma virus (HPV) infection in esophageal squamous cell carcinomas (ESCC) and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of ...AIM: To look for the evidence of human papilloma virus (HPV) infection in esophageal squamous cell carcinomas (ESCC) and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of esophageal carcinomas in Henan emigrants. METHODS: Papilloma virus (PV) and HPV were determined by UltrasensiveTM S-P immunohistochemistry (IHC) and in situ hybridization (ISH) in esophageal carcinoma tissues (82 cases) and the normal mucosa (40 cases). RESULTS: IHC revealed that the positive rate of PV was 75.0%, 68.18% and 72.5% respectively while the HPV (16/18-E6) positive rate was 45.0%, 36.36%, 37.5%, respectively in esophageal carcinoma tissue specimens from Henan emigrants,the local citizens and patients in Hubei Cancer Hospital. The PV and HPV (16/18-E6) were negative in all normal esophageal mucosa specimens. No correlation was found between HPV in esophageal squamous cell carcinoma tissues and in grade 1-3 esophageal squamous cell carcinoma cells. In situ hybridization showed that the HPV (16/18) DNA positive rate was 30.0%, 31.8%, 25.0%, respectively in the 3 groups of samples. No positive hybridization signal was found in 40 normal esophageal mucosa specimens. The positive rate of HPV (16/18) DNA in the esophageal carcinoma specimens was significantly higher than that in normal mucosa specimens (P〈0.05). The positive rate was not different among the 3 groups of esophageal carcinoma tissue specimens (P〉0.05).CONCLUSION: HPV infection is high in esophageal carcinoma of Henan emigrants, local residents and patients in Hubei Cancer Hospital. HPV is closely related with esophageal squarnous cell carcinoma. HPV infection may play an important role in esophageal squarnous cell carcinoma.展开更多
The corrosion behaviors of Sn-0.75Cu solder and Sn-0.75Cu/Cu joint in 3.5% NaCl(mass fraction) solution were studied by potentiodynamic polarization test and leaching measurement.The polarization curves indicated th...The corrosion behaviors of Sn-0.75Cu solder and Sn-0.75Cu/Cu joint in 3.5% NaCl(mass fraction) solution were studied by potentiodynamic polarization test and leaching measurement.The polarization curves indicated that the corrosion rate of Sn-0.75Cu solder was lower than that of Sn-0.75Cu/Cu joint.The morphology observation and phase composition analysis on the corroded product at each interesting potential suggested that Sn3O(OH)2Cl2 formed on the surface of Sn-0.75Cu solder at active dissolution stage.As the potential increased from active/passive transition stage,all the surface of Sn-0.75Cu solder was covered by the Sn3O(OH)2Cl2 and some pits appeared after the polarization test.Compared to the Sn-0.75Cu solder alloy,much more Sn3O(OH)2Cl2 formed at active dissolution stage and the pits with bigger size were observed after polarization test for the Sn-0.75Cu/Cu solder joints.The leaching test confirmed that the faster electrochemical corrosion rate resulted in the larger amount of Sn released from the Sn-0.75Cu/Cu solder joints.展开更多
One promising joining method for NiTi-SMA (shape memory alloy)-components is laser welding. This joining technology bears huge potential regarding process automation and mechanical properties as well as durability, ...One promising joining method for NiTi-SMA (shape memory alloy)-components is laser welding. This joining technology bears huge potential regarding process automation and mechanical properties as well as durability, especially within the field of small- and medium-sized actuators. However, there is still need for research due to unsolved issues influencing the microstructure and thus effecting mechanical properties as well as SMA-characteristics of these joints. Therefore, the purpose of this paper is the evaluation of quality parameters of NiTi-NiTi-wire-joints. For this purpose, design of experiments with a fractional factorial design is used for the investigation, because of its high potential to decrease experimental effort. This paper provides a basis for future research in the field of SMA-actuators and joining.展开更多
Scalp care is important in maintaining good conditions of scalp and hair. Key technical approaches for scalp care include reducing the chance of scalp inflammation, improving scalp defense, and activating hair follicl...Scalp care is important in maintaining good conditions of scalp and hair. Key technical approaches for scalp care include reducing the chance of scalp inflammation, improving scalp defense, and activating hair follicle cells. As the cosmetics industry is moving toward to alternative methods to animal testing based on the 3 Rs(Replacement, Reduction and Refinement), in vitro methods will be widely used to evaluate the effects of scalp care. In this paper, we describe the detailed technical approaches for scalp care and the in vitro evaluation methods for skin irritation, anti-inflammation, barrier function, blood circulation, hair growth and male pattern hair loss prevention, respectively.展开更多
This paper presents a novel capacitance probe, i.e., paraUel-wire capacitance probe (PWCP), for two-phase flow measurement. Using finite element method (FEM), the sensitivity field of the PWCP is investigated and ...This paper presents a novel capacitance probe, i.e., paraUel-wire capacitance probe (PWCP), for two-phase flow measurement. Using finite element method (FEM), the sensitivity field of the PWCP is investigated and the optimum sensor geometry is determiend in term of the characterisitc parameters. Then, the response of PWCP for the oil-water stratified flow is calculated, and it is found the PWCP has better linearity and sensitivity to the variation of water-layer thickness, and is almost independant of the angle between the oil-water interface and the sensor electrode. Finally, the static experiment for oil-water stratified flow is carried out and the calibration method of liquid holdup is presented.展开更多
A two-dimensional numerical model was used to explain the liquefaction mechanism of double sand lenses and the corresponding soil deformation due to the cyclic loading. Moreover, in order to investigate the influences...A two-dimensional numerical model was used to explain the liquefaction mechanism of double sand lenses and the corresponding soil deformation due to the cyclic loading. Moreover, in order to investigate the influences of the soil characteristics and input loading data a parametric study was carried out on the essential parameters affecting the soil settlement, and so the variation of these parameters with the corresponding displacements was mainly examined. At last, the results obtained from the numerical analyses of double sand lenses and a continuous sand layer with similar characteristics were compared with those of an estimating method proposed by ISHIHARA and YOSHIMINE. The comparisons show that the settlements due to liquefaction of the continuous sand layer in both numerical and the estimating method are in a good agreement with and are obviously greater than those of double sand lenses.展开更多
Mobbing behavior is an important and widespread antipredatory behavior. This is a well-known behavior especially in birds. There are many studies about mobbing in birds, and most of them use owls as a model of predato...Mobbing behavior is an important and widespread antipredatory behavior. This is a well-known behavior especially in birds. There are many studies about mobbing in birds, and most of them use owls as a model of predator. However it is not clear how mobbing works when a predator assume a role of a prey. In this paper we organize field observations, which were taken on records of mobbing behaviors performed by owls or by other animals against them. These observations were collected nearby four Brazilian cities in South-Eastern and Central Brazil: Joao Monlevade / MG, Sacramento / MG Baguari / MG and Cacu / GO. Events of mobbing behavior have always involved prey(s) and predator(s) thus, in this study we presents mobbing events which species of owl always were involved, and beside the owls, other animals like mammals or raptors. These records are important due to their infrequency and problems to be detected in natural field conditions. It is rare mobbing events when an owl assumes a role of a prey, and there are few studies that show the mobbing by the predator optics. The present data may contribute for elucidation of mobbing behavior intrinsic aspects.展开更多
The tilting-train is very attractive to the railroad users in the world due to the advantage of high speed in curved track using pre-existing infrastructure of railway.Tilting-train has a unique allowable speed and me...The tilting-train is very attractive to the railroad users in the world due to the advantage of high speed in curved track using pre-existing infrastructure of railway.Tilting-train has a unique allowable speed and mechanism especially in curved track.In this work,when tilting-train is operated with the allowable speed,the behavior of roadbed is evaluated by examining its settlement and bearing capacity.Additionally,the stability of roadbed is estimated as the roadbed is in the condition of soft soil influenced by the weather effects and cyclic train loading.Numerical results show that the roadbed settlement satisfies the allowable settlement when the elastic moduli of upper roadbed and in-situ soil are greater than 3800 and 4600 kN/m2 for rail joint and 2300 and 3300 kN/m2 for continuous welded rail(CWR).展开更多
基金Project(51305292)supported by the National Natural Science Foundation of ChinaProject(20105429001)supported by the National Aeronautical Science Foundation of China
文摘Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechanism of heat generationwas discussed. Fatigue limit of the welded joint was predicted and the fatigue damage was also assessed based ontheevolution of the temperatureand hotspot zone on the specimen surfaceduring fatigue tests. The presented results show that infrared thermography can not onlyquicklypredict the fatigue behavior of the welded joint, but also qualitatively identify the evolution of fatigue damage in real time. It is found that the predicted fatigue limit agrees well with the conventionalS-Nexperimental results. The evolution of the temperatureand hotspot zone on the specimen surface can be an effectivefatigue damage indicatorfor effectiveevaluationof magnesium alloy electron beam welded joint.
文摘The location of U-turn bays is an important consideration in indirect driveway left-turn treatments.In order to improve the performance of right-turns followed by U-turns(RTUTs),this study evaluates the impacts of the separation distances between driveway exits and downstream U-turn locations on the safety and operational performance of vehicles making RTUTs.Crash data are investigated at 179 selected roadway segments,and travel time data are measured using video cameras at 29 locations in the state of Florida,USA.Crash rate models and travel time models are developed based on data collected in the field.It is found that the separation distance between driveway exits and downstream U-turn locations significantly impacts the safety and operational performance of vehicles making right turns followed by U-turns.Based on the research results,the minimum and optimal separation distances between driveways and U-turn locations under different roadway conditions are determined to facilitate driver use of RTUTs.The results of this study can be used for future intersection improvement projects in China.
文摘Migraine is a complex and heterogeneous disorder. Although several genetic models has been proposed including autosomal-dominant/autosomal recessive, sex-linked, sex-limited, mitochondrial, and multi-gene, none of these models can well-explain the transmission of the disease. We hypothesied that migraine is a sex-conditioned inherited disorder (autosomal dominant in females and autosomal recessive in males). This hypothesis is supported by the evidence such as the locations of genes associated with familial hemiplegic migraine, possibly "typical" migraine as well (dominantly on chromosome 19p, lq, and 2q), male:female ratio of prevalence (1:2-1:4), the mostly youth-onset, the provocation by the contraceptives, the induction by menstruation, and the self-limitation after menopause. Female sex-hormones appear to be the key contributor to a higher prevalence of migraine in female. Socio-environmental factors may also play an important role.
基金Council of Scientific and Industrial Research (CSIR), New Delhi, India, for the financial support to carry out this investigation through sponsored project No. 22(0615)/13/EMR-II dated 26.02.2013
文摘Joining of dissimilar metals will offer many advantages in transportation sectors such as fuel consumption,weightreduction and emission reduction.However,joining of aluminium(Al)alloys with magnesium(Mg)alloys by fusion welding processis very complicated.Friction stir welding(FSW)is a feasible method to join these two dissimilar alloys.Mixing these two metalstogether in stir zone(SZ)leads to poor corrosion resistance.In this investigation,an attempt has been made to understand thecorrosion resistance of SZ of FSWed dissimilar joints of AA6061Al alloy and AZ31B Mg alloy.Potentiodynamic polarization testwas conducted by varying chloride ion concentration,pH value of the NaCl solution and exposure time.The corroded surfaces wereanalyzed using optical microscopy,scanning electron microscopy and XRD techniques.Of these three factors investigated,exposuretime is found to be the most significant factor to influence the corrosion behaviour of SZ of friction stir welded dissimilar joints ofAl/Mg alloys.
基金Supported by Key Technology R&D Program of Hubei Province, No.2004AA304B08
文摘AIM: To look for the evidence of human papilloma virus (HPV) infection in esophageal squamous cell carcinomas (ESCC) and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of esophageal carcinomas in Henan emigrants. METHODS: Papilloma virus (PV) and HPV were determined by UltrasensiveTM S-P immunohistochemistry (IHC) and in situ hybridization (ISH) in esophageal carcinoma tissues (82 cases) and the normal mucosa (40 cases). RESULTS: IHC revealed that the positive rate of PV was 75.0%, 68.18% and 72.5% respectively while the HPV (16/18-E6) positive rate was 45.0%, 36.36%, 37.5%, respectively in esophageal carcinoma tissue specimens from Henan emigrants,the local citizens and patients in Hubei Cancer Hospital. The PV and HPV (16/18-E6) were negative in all normal esophageal mucosa specimens. No correlation was found between HPV in esophageal squamous cell carcinoma tissues and in grade 1-3 esophageal squamous cell carcinoma cells. In situ hybridization showed that the HPV (16/18) DNA positive rate was 30.0%, 31.8%, 25.0%, respectively in the 3 groups of samples. No positive hybridization signal was found in 40 normal esophageal mucosa specimens. The positive rate of HPV (16/18) DNA in the esophageal carcinoma specimens was significantly higher than that in normal mucosa specimens (P〈0.05). The positive rate was not different among the 3 groups of esophageal carcinoma tissue specimens (P〉0.05).CONCLUSION: HPV infection is high in esophageal carcinoma of Henan emigrants, local residents and patients in Hubei Cancer Hospital. HPV is closely related with esophageal squarnous cell carcinoma. HPV infection may play an important role in esophageal squarnous cell carcinoma.
基金Project (2005DKA10400-Z23) supported by Chinese National Science and Technology InfrastructureProject (DUT10R:(3)65) supported by Fundamental Research Funds for the Central Universities,China
文摘The corrosion behaviors of Sn-0.75Cu solder and Sn-0.75Cu/Cu joint in 3.5% NaCl(mass fraction) solution were studied by potentiodynamic polarization test and leaching measurement.The polarization curves indicated that the corrosion rate of Sn-0.75Cu solder was lower than that of Sn-0.75Cu/Cu joint.The morphology observation and phase composition analysis on the corroded product at each interesting potential suggested that Sn3O(OH)2Cl2 formed on the surface of Sn-0.75Cu solder at active dissolution stage.As the potential increased from active/passive transition stage,all the surface of Sn-0.75Cu solder was covered by the Sn3O(OH)2Cl2 and some pits appeared after the polarization test.Compared to the Sn-0.75Cu solder alloy,much more Sn3O(OH)2Cl2 formed at active dissolution stage and the pits with bigger size were observed after polarization test for the Sn-0.75Cu/Cu solder joints.The leaching test confirmed that the faster electrochemical corrosion rate resulted in the larger amount of Sn released from the Sn-0.75Cu/Cu solder joints.
文摘One promising joining method for NiTi-SMA (shape memory alloy)-components is laser welding. This joining technology bears huge potential regarding process automation and mechanical properties as well as durability, especially within the field of small- and medium-sized actuators. However, there is still need for research due to unsolved issues influencing the microstructure and thus effecting mechanical properties as well as SMA-characteristics of these joints. Therefore, the purpose of this paper is the evaluation of quality parameters of NiTi-NiTi-wire-joints. For this purpose, design of experiments with a fractional factorial design is used for the investigation, because of its high potential to decrease experimental effort. This paper provides a basis for future research in the field of SMA-actuators and joining.
文摘Scalp care is important in maintaining good conditions of scalp and hair. Key technical approaches for scalp care include reducing the chance of scalp inflammation, improving scalp defense, and activating hair follicle cells. As the cosmetics industry is moving toward to alternative methods to animal testing based on the 3 Rs(Replacement, Reduction and Refinement), in vitro methods will be widely used to evaluate the effects of scalp care. In this paper, we describe the detailed technical approaches for scalp care and the in vitro evaluation methods for skin irritation, anti-inflammation, barrier function, blood circulation, hair growth and male pattern hair loss prevention, respectively.
基金Supported by the National Natural Science Foundation of China (50974095, 41174109, 61104148), and the National Science and Technology Mai or Projects (2011ZX05020-006).
文摘This paper presents a novel capacitance probe, i.e., paraUel-wire capacitance probe (PWCP), for two-phase flow measurement. Using finite element method (FEM), the sensitivity field of the PWCP is investigated and the optimum sensor geometry is determiend in term of the characterisitc parameters. Then, the response of PWCP for the oil-water stratified flow is calculated, and it is found the PWCP has better linearity and sensitivity to the variation of water-layer thickness, and is almost independant of the angle between the oil-water interface and the sensor electrode. Finally, the static experiment for oil-water stratified flow is carried out and the calibration method of liquid holdup is presented.
文摘A two-dimensional numerical model was used to explain the liquefaction mechanism of double sand lenses and the corresponding soil deformation due to the cyclic loading. Moreover, in order to investigate the influences of the soil characteristics and input loading data a parametric study was carried out on the essential parameters affecting the soil settlement, and so the variation of these parameters with the corresponding displacements was mainly examined. At last, the results obtained from the numerical analyses of double sand lenses and a continuous sand layer with similar characteristics were compared with those of an estimating method proposed by ISHIHARA and YOSHIMINE. The comparisons show that the settlements due to liquefaction of the continuous sand layer in both numerical and the estimating method are in a good agreement with and are obviously greater than those of double sand lenses.
文摘Mobbing behavior is an important and widespread antipredatory behavior. This is a well-known behavior especially in birds. There are many studies about mobbing in birds, and most of them use owls as a model of predator. However it is not clear how mobbing works when a predator assume a role of a prey. In this paper we organize field observations, which were taken on records of mobbing behaviors performed by owls or by other animals against them. These observations were collected nearby four Brazilian cities in South-Eastern and Central Brazil: Joao Monlevade / MG, Sacramento / MG Baguari / MG and Cacu / GO. Events of mobbing behavior have always involved prey(s) and predator(s) thus, in this study we presents mobbing events which species of owl always were involved, and beside the owls, other animals like mammals or raptors. These records are important due to their infrequency and problems to be detected in natural field conditions. It is rare mobbing events when an owl assumes a role of a prey, and there are few studies that show the mobbing by the predator optics. The present data may contribute for elucidation of mobbing behavior intrinsic aspects.
基金supported by the 2014 Inje University research grant
文摘The tilting-train is very attractive to the railroad users in the world due to the advantage of high speed in curved track using pre-existing infrastructure of railway.Tilting-train has a unique allowable speed and mechanism especially in curved track.In this work,when tilting-train is operated with the allowable speed,the behavior of roadbed is evaluated by examining its settlement and bearing capacity.Additionally,the stability of roadbed is estimated as the roadbed is in the condition of soft soil influenced by the weather effects and cyclic train loading.Numerical results show that the roadbed settlement satisfies the allowable settlement when the elastic moduli of upper roadbed and in-situ soil are greater than 3800 and 4600 kN/m2 for rail joint and 2300 and 3300 kN/m2 for continuous welded rail(CWR).