The effective utilisation of steel fibre reinforced concrete (SFRC) requires in-depth and detailed understanding of bonding mechanisms governing the tensile behaviour. In response to this demand, this study presents a...The effective utilisation of steel fibre reinforced concrete (SFRC) requires in-depth and detailed understanding of bonding mechanisms governing the tensile behaviour. In response to this demand, this study presents an empirical description of the axial force required to pull out a hooked end steel fibre from a cementitious matrix. It is based upon consistent experimental tests that show the force versus displacement plot is formed from a sequence of events in which partial and full debonding at the interface is followed by bending of the hook knee to raise the force to its maximum. A loss of peak force occurs with the reversed plasticity involved in a full straightening of the fibre that precedes the rapid sliding to its full removal under a falling force. The stages are assembled in the said order with a piecewise connection between linear segments and a curve of exponential decay. A power law can be introduced to describe the knee bending stage if preferred. The normalised co-ordinates were adopted for the simple mathematical discontinuous function of the full pull-out process. Normalising force and displacement for hooked fibre is based upon the maximum values found for straight fibre pull out. This would apply to an overall embedded length of unity and a unit peak force for a full debonding of straight fibre in similar materials. For hooked fibre the normalised co-ordinates given refer to the initiation and duration of each event to be tabulated at fractions of the embedded length with multiples of that force. Such predictions are seen to be in good agreement with average pull-out response curves.展开更多
SIX thousand kilometers!10,000 li! 3000 yearsold! The only man-madestructure that can be seenfrom the moon! The bricks alonewould build four Egyptian pyra-mids! Wide enough for fourhorses abreast! You are not aman unt...SIX thousand kilometers!10,000 li! 3000 yearsold! The only man-madestructure that can be seenfrom the moon! The bricks alonewould build four Egyptian pyra-mids! Wide enough for fourhorses abreast! You are not aman until you’ve been to theWall! We have all heard at leastone of these claims.展开更多
China ramps up its efforts to safeguard juveniles from the Internet gaming addiction Just before this year’s national college entrance exam,or the gaokao,on June 7-8,a letter from a despairing mother of student made ...China ramps up its efforts to safeguard juveniles from the Internet gaming addiction Just before this year’s national college entrance exam,or the gaokao,on June 7-8,a letter from a despairing mother of student made a big splash on Weibo,a Chinese Twitter-like microblogging platform.The mother described how her son,who used to be an outstanding learner,failed the exam展开更多
The new Chinese action RPG Black Myth:Wukong has gained global popularity by incorporating many Chinese cultural elements into its storyline,which is based on the Monkey King from the classic novel Journey to the West...The new Chinese action RPG Black Myth:Wukong has gained global popularity by incorporating many Chinese cultural elements into its storyline,which is based on the Monkey King from the classic novel Journey to the West.Many players have commented that the game’s cut scenes and visuals alone have yingkonged them,keeping them hooked for a long time.展开更多
BACKGROUND Hook of hamate fractures occur either due to repetitive stress from gripping sports(e.g.,golf,tennis,and baseball),leading to fatigue fracture,or as a result of trauma from falls or other injuries.The recom...BACKGROUND Hook of hamate fractures occur either due to repetitive stress from gripping sports(e.g.,golf,tennis,and baseball),leading to fatigue fracture,or as a result of trauma from falls or other injuries.The recommended treatment involves the excision of bone fragments to facilitate athletes’early return to sports;excision surgery is also performed in trauma cases.However,some patients prefer nonsurgical treatment options,and conservative treatment should be considered.AIM To present a case series of 16 patients conservatively treated for hook of hamate fractures.METHODS This study included 16(11 males and 5 females;right side,6 cases;left side,10)patients who desired conservative treatment and could be followed-up until bone union was achieved.The average age of the patients was 49.6(range:24-72)years.The average time from injury to consultation was 4.3(range:0.2-21.4)weeks.The treatment involved 4 weeks of casting from the forearm to the metacarpophalangeal joint,followed by 8 weeks of splint fixation of the wrist.Follow-up computed tomography scans were performed every 4 weeks.RESULTS Bone union was achieved in all patients.The average duration of casting was 3.7(range:0-5)weeks and that of splint fixation thereafter was 8.6(range:0-28)weeks.The patients did not exhibit joint contractures or range of motion restrictions due to prolonged immobilization.CONCLUSION Conservative treatment with external fixation may be an option for hook of hamate fractures.展开更多
BACKGROUND Clavicle fractures are a common type of fracture that often occurs after high-energy trauma.The treatment methods for clavicle fractures remain controversial.Both locking compression and hook plates are rec...BACKGROUND Clavicle fractures are a common type of fracture that often occurs after high-energy trauma.The treatment methods for clavicle fractures remain controversial.Both locking compression and hook plates are recommended.CASE SUMMARY A 44-year-old male suffered an injury during skiing.Radiography revealed a right-sided distal clavicular fracture.The fracture was treated using a hook plate due to its small size.During the surgical procedure,Kirschner wires were used to drill holes in the acromion.The end of the hook plate was inserted into the hole rather than below the edge of the acromion.CONCLUSION One year later,imaging revealed complete healing of the fracture,and the hook plate was removed.The patient was satisfied with the course and treatment results.Additionally,a new classification system was proposed based on the degree of injury to the distal clavicle joint surface.The incidence of postoperative complications associated with the use of hook plates for clavicular fracture treatment is relatively high.Complications can be reduced by changing the hook plate placement.展开更多
This editorial critically evaluates the landmark study by Tanaka and Yoshii,which demonstrated a 100%union rate with conservative management of hamate hook fractures,challenging the historical preference for surgical ...This editorial critically evaluates the landmark study by Tanaka and Yoshii,which demonstrated a 100%union rate with conservative management of hamate hook fractures,challenging the historical preference for surgical intervention.In contrast to Scheufle et al’s report of 90%-100%failure rates with early surgical approaches,Tanaka and Yoshii’s protocol achieved universal healing despite delayed diagnoses in 25%of cases.Central to this success is the systematic inte-gration of high-resolution computed tomography for early diagnosis and dynamic monitoring of trabecular bone regeneration,significantly reducing missed dia-gnoses and guiding personalized immobilization timelines.The patient-centered strategy—allowing temporary splint removal during low-risk activities—balanced fracture stability with joint mobility preservation,avoiding post-treatment stiff-ness.However,limitations such as small sample size(n=16),selection bias,and insufficient long-term functional data(e.g.,grip strength,return-to-sport metrics)underscore the need for comparative trials.Emerging trends,including adjunct therapies like low-intensity pulsed ultrasound and biologics(e.g.,teriparatide),are proposed to accelerate healing while minimizing immobilization risks.This work redefines conservative fracture management paradigms,emphasizing in-novation without compromising efficacy.Overall,this assessment deepens our understanding of the conservative management of hook fractures and provides evidence-based insights for improved clinical decision-making.展开更多
The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy,and its distribution chara...The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy,and its distribution characteristics were determined.Numerical simulations confirmed that the freezing–overflow mechanism is the primary cause of hook formation.They also revealed that the freezing event occurs unpredictably,while the overflow event takes place during the positive strip time.The average pitch of oscillation marks(OMs)on the slab surface was 8.693 mm,while the theoretical pitch was 8.889 mm,with a difference of approximately 2%.This discrepancy primarily results from varying degrees of overflow,which affects the morphology of the OMs and the positions of their deepest points.Notably,this result further confirmed that the freezing and overflow in the meniscus were indeed caused by the periodic oscillation of the mold.Higher superheat hindered hook formation,leading to a negative correlation between the hook depth distribution around the slab and the temperature distribution within the mold.Therefore,the depth of the corner hook was greater than that of other positions,which was caused by the intensified cooling effect of the corner.Moreover,key factors influencing hook development were analyzed,providing insights into transient fluid flow and heat transfer characteristics within the mold.Transient fluid flow and heat transfer contributed to the randomness and tendency of hook formation.This randomness was reflected in the varying angles of the hooks,whereas the tendency was evident in the negative correlation between superheat and hook length.Based on the randomness and tendency of hook formation and its profile characteristics,a new method for controlling hook depth based on“sine law”is proposed.展开更多
During the continuous casting process of low carbon steel,the solidified hook formed in the mold has great effects on the surface quality of the cast slab.Some factory experiments have been conducted to investigate th...During the continuous casting process of low carbon steel,the solidified hook formed in the mold has great effects on the surface quality of the cast slab.Some factory experiments have been conducted to investigate the microscopic characteristics and reveal the influence of process parameters on solidified hooks.The depth of the hooks showed a positive correlation with the deflection angle,length,and oscillation mark(OM)depth,which indicates that the OM depth can serve as an approximate indicator for evaluating the depth of the solidified hooks.On the wide and narrow faces of the cast slab,the depth of the solidified hooks and the temperature distribution in the mold show opposite trends,with lower depths of solidified hooks at positions with higher temperatures.In addition,the influence of process parameters on solidified hooks was analyzed.With the increase in superheat,not only the depth of solidified hooks gradually decreases,but also the ratio of depression-typed marks increases.Increasing casting speed and decreasing immersion depth of the submerged entry nozzle will both lead to a decrease in the depth of the solidified hook.展开更多
Chinese psychologists outline criteria for Internet addiction Day after day you are glued to your computer screen.You cannot get enough of online games,net shop-ping or cyber surfing.Your social life dete-riorates,and...Chinese psychologists outline criteria for Internet addiction Day after day you are glued to your computer screen.You cannot get enough of online games,net shop-ping or cyber surfing.Your social life dete-riorates,and so does your health.Chancesare that you are addicted to the Internet and you need counseling.展开更多
According to the boot process of modern computer systems,whoever boots first will gain control first.Taking advantage of this feature,a malicious code called bootkit can hijack the control before the OS bootloader and...According to the boot process of modern computer systems,whoever boots first will gain control first.Taking advantage of this feature,a malicious code called bootkit can hijack the control before the OS bootloader and bypass security mechanisms in boot process.That makes bootkits difficult to detect or clean up thoroughly.With the improvement of security mechanisms and the emergence of UEFI,the attack and defense techniques for bootkits have constantly been evolving.We first introduce two boot modes of modern computer systems and present an attack model of bootkits by some sophistical samples.Then we discuss some classic attack techniques used by bootkits from their initial appearance to the present on two axes,including boot mode axis and attack phase axis.Next,we evaluate the race to the bottom of the system and the evolution process between bootkits and security mechanisms.At last,we present the possible future direction for bootkits in the context of continuous improvement of OS and firmware security mechanisms.展开更多
文摘The effective utilisation of steel fibre reinforced concrete (SFRC) requires in-depth and detailed understanding of bonding mechanisms governing the tensile behaviour. In response to this demand, this study presents an empirical description of the axial force required to pull out a hooked end steel fibre from a cementitious matrix. It is based upon consistent experimental tests that show the force versus displacement plot is formed from a sequence of events in which partial and full debonding at the interface is followed by bending of the hook knee to raise the force to its maximum. A loss of peak force occurs with the reversed plasticity involved in a full straightening of the fibre that precedes the rapid sliding to its full removal under a falling force. The stages are assembled in the said order with a piecewise connection between linear segments and a curve of exponential decay. A power law can be introduced to describe the knee bending stage if preferred. The normalised co-ordinates were adopted for the simple mathematical discontinuous function of the full pull-out process. Normalising force and displacement for hooked fibre is based upon the maximum values found for straight fibre pull out. This would apply to an overall embedded length of unity and a unit peak force for a full debonding of straight fibre in similar materials. For hooked fibre the normalised co-ordinates given refer to the initiation and duration of each event to be tabulated at fractions of the embedded length with multiples of that force. Such predictions are seen to be in good agreement with average pull-out response curves.
文摘SIX thousand kilometers!10,000 li! 3000 yearsold! The only man-madestructure that can be seenfrom the moon! The bricks alonewould build four Egyptian pyra-mids! Wide enough for fourhorses abreast! You are not aman until you’ve been to theWall! We have all heard at leastone of these claims.
文摘China ramps up its efforts to safeguard juveniles from the Internet gaming addiction Just before this year’s national college entrance exam,or the gaokao,on June 7-8,a letter from a despairing mother of student made a big splash on Weibo,a Chinese Twitter-like microblogging platform.The mother described how her son,who used to be an outstanding learner,failed the exam
文摘The new Chinese action RPG Black Myth:Wukong has gained global popularity by incorporating many Chinese cultural elements into its storyline,which is based on the Monkey King from the classic novel Journey to the West.Many players have commented that the game’s cut scenes and visuals alone have yingkonged them,keeping them hooked for a long time.
文摘BACKGROUND Hook of hamate fractures occur either due to repetitive stress from gripping sports(e.g.,golf,tennis,and baseball),leading to fatigue fracture,or as a result of trauma from falls or other injuries.The recommended treatment involves the excision of bone fragments to facilitate athletes’early return to sports;excision surgery is also performed in trauma cases.However,some patients prefer nonsurgical treatment options,and conservative treatment should be considered.AIM To present a case series of 16 patients conservatively treated for hook of hamate fractures.METHODS This study included 16(11 males and 5 females;right side,6 cases;left side,10)patients who desired conservative treatment and could be followed-up until bone union was achieved.The average age of the patients was 49.6(range:24-72)years.The average time from injury to consultation was 4.3(range:0.2-21.4)weeks.The treatment involved 4 weeks of casting from the forearm to the metacarpophalangeal joint,followed by 8 weeks of splint fixation of the wrist.Follow-up computed tomography scans were performed every 4 weeks.RESULTS Bone union was achieved in all patients.The average duration of casting was 3.7(range:0-5)weeks and that of splint fixation thereafter was 8.6(range:0-28)weeks.The patients did not exhibit joint contractures or range of motion restrictions due to prolonged immobilization.CONCLUSION Conservative treatment with external fixation may be an option for hook of hamate fractures.
文摘BACKGROUND Clavicle fractures are a common type of fracture that often occurs after high-energy trauma.The treatment methods for clavicle fractures remain controversial.Both locking compression and hook plates are recommended.CASE SUMMARY A 44-year-old male suffered an injury during skiing.Radiography revealed a right-sided distal clavicular fracture.The fracture was treated using a hook plate due to its small size.During the surgical procedure,Kirschner wires were used to drill holes in the acromion.The end of the hook plate was inserted into the hole rather than below the edge of the acromion.CONCLUSION One year later,imaging revealed complete healing of the fracture,and the hook plate was removed.The patient was satisfied with the course and treatment results.Additionally,a new classification system was proposed based on the degree of injury to the distal clavicle joint surface.The incidence of postoperative complications associated with the use of hook plates for clavicular fracture treatment is relatively high.Complications can be reduced by changing the hook plate placement.
文摘This editorial critically evaluates the landmark study by Tanaka and Yoshii,which demonstrated a 100%union rate with conservative management of hamate hook fractures,challenging the historical preference for surgical intervention.In contrast to Scheufle et al’s report of 90%-100%failure rates with early surgical approaches,Tanaka and Yoshii’s protocol achieved universal healing despite delayed diagnoses in 25%of cases.Central to this success is the systematic inte-gration of high-resolution computed tomography for early diagnosis and dynamic monitoring of trabecular bone regeneration,significantly reducing missed dia-gnoses and guiding personalized immobilization timelines.The patient-centered strategy—allowing temporary splint removal during low-risk activities—balanced fracture stability with joint mobility preservation,avoiding post-treatment stiff-ness.However,limitations such as small sample size(n=16),selection bias,and insufficient long-term functional data(e.g.,grip strength,return-to-sport metrics)underscore the need for comparative trials.Emerging trends,including adjunct therapies like low-intensity pulsed ultrasound and biologics(e.g.,teriparatide),are proposed to accelerate healing while minimizing immobilization risks.This work redefines conservative fracture management paradigms,emphasizing in-novation without compromising efficacy.Overall,this assessment deepens our understanding of the conservative management of hook fractures and provides evidence-based insights for improved clinical decision-making.
基金financially supported by the National Natural Science Foundation of China(No.52174306)the Fundamental Research Funds for the Central Universities(Nos.N2225023 and N2425006)the Basic Research Projects of Liaoning Provincial Department of Education(No.LJ212410148027)。
文摘The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy,and its distribution characteristics were determined.Numerical simulations confirmed that the freezing–overflow mechanism is the primary cause of hook formation.They also revealed that the freezing event occurs unpredictably,while the overflow event takes place during the positive strip time.The average pitch of oscillation marks(OMs)on the slab surface was 8.693 mm,while the theoretical pitch was 8.889 mm,with a difference of approximately 2%.This discrepancy primarily results from varying degrees of overflow,which affects the morphology of the OMs and the positions of their deepest points.Notably,this result further confirmed that the freezing and overflow in the meniscus were indeed caused by the periodic oscillation of the mold.Higher superheat hindered hook formation,leading to a negative correlation between the hook depth distribution around the slab and the temperature distribution within the mold.Therefore,the depth of the corner hook was greater than that of other positions,which was caused by the intensified cooling effect of the corner.Moreover,key factors influencing hook development were analyzed,providing insights into transient fluid flow and heat transfer characteristics within the mold.Transient fluid flow and heat transfer contributed to the randomness and tendency of hook formation.This randomness was reflected in the varying angles of the hooks,whereas the tendency was evident in the negative correlation between superheat and hook length.Based on the randomness and tendency of hook formation and its profile characteristics,a new method for controlling hook depth based on“sine law”is proposed.
基金the financial support of National Key Research and Development Plan(No.2021YFB3702000)National Natural Science of China(Nos.52074076,52174306 and U20A20272)Fundamental Research Funds for the Central Universities(Nos.N2225023 and N2425006).Author information。
文摘During the continuous casting process of low carbon steel,the solidified hook formed in the mold has great effects on the surface quality of the cast slab.Some factory experiments have been conducted to investigate the microscopic characteristics and reveal the influence of process parameters on solidified hooks.The depth of the hooks showed a positive correlation with the deflection angle,length,and oscillation mark(OM)depth,which indicates that the OM depth can serve as an approximate indicator for evaluating the depth of the solidified hooks.On the wide and narrow faces of the cast slab,the depth of the solidified hooks and the temperature distribution in the mold show opposite trends,with lower depths of solidified hooks at positions with higher temperatures.In addition,the influence of process parameters on solidified hooks was analyzed.With the increase in superheat,not only the depth of solidified hooks gradually decreases,but also the ratio of depression-typed marks increases.Increasing casting speed and decreasing immersion depth of the submerged entry nozzle will both lead to a decrease in the depth of the solidified hook.
文摘Chinese psychologists outline criteria for Internet addiction Day after day you are glued to your computer screen.You cannot get enough of online games,net shop-ping or cyber surfing.Your social life dete-riorates,and so does your health.Chancesare that you are addicted to the Internet and you need counseling.
基金supported by NSFC under Grant 62172308,Grant U1626107,Grant 61972297 and Grant 62172144。
文摘According to the boot process of modern computer systems,whoever boots first will gain control first.Taking advantage of this feature,a malicious code called bootkit can hijack the control before the OS bootloader and bypass security mechanisms in boot process.That makes bootkits difficult to detect or clean up thoroughly.With the improvement of security mechanisms and the emergence of UEFI,the attack and defense techniques for bootkits have constantly been evolving.We first introduce two boot modes of modern computer systems and present an attack model of bootkits by some sophistical samples.Then we discuss some classic attack techniques used by bootkits from their initial appearance to the present on two axes,including boot mode axis and attack phase axis.Next,we evaluate the race to the bottom of the system and the evolution process between bootkits and security mechanisms.At last,we present the possible future direction for bootkits in the context of continuous improvement of OS and firmware security mechanisms.
