The vortex-induced vibration of two identical rigidly mounted risers in a parallel arrangement was studied using Ansys-CFX and model tests.The vortex shedding and force were recorded to determine the effect of spacing...The vortex-induced vibration of two identical rigidly mounted risers in a parallel arrangement was studied using Ansys-CFX and model tests.The vortex shedding and force were recorded to determine the effect of spacing on the two-degree-of-freedom oscillation of the risers.CFX was used to study the single riser and two parallel risers in 2–8D spacing considering the coupling effect.Because of the limited width of water channel,only three different riser spacings,2D,3D,and 4D,were tested to validate the characteristics of the two parallel risers by comparing to the numerical simulation.The results indicate that the lift force changes significantly with the increase in spacing,and in the case of 3D spacing,the lift force of the two parallel risers reaches the maximum.The vortex shedding of the risers in 3D spacing shows that a variable velocity field with the same frequency as the vortex shedding is generated in the overlapped area,thus equalizing the period of drag force to that of lift force.It can be concluded that the interaction between the two parallel risers is significant when the risers are brought to a small distance between them because the trajectory of riser changes from oval to curve 8 as the spacing is increased.The phase difference of lift force between the two risers is also different as the spacing changes.展开更多
AIM:To determine the incidence and factors responsible for anastomotic leaks and stricture following anterior resection(AR)and its subsequent management.METHODS:Retrospective analysis of data from 108 patients with re...AIM:To determine the incidence and factors responsible for anastomotic leaks and stricture following anterior resection(AR)and its subsequent management.METHODS:Retrospective analysis of data from 108 patients with rectal carcinoma who underwent AR or low anterior resection(LAR)to identify the various preoperative,operative,and post operative factors that might have influence on anastomotic leaks and strictures.RESULTS:There were 68 males and 40 females with an average of 47 years(range 21-75 years).The median distance of the tumor from the anal verge was 8 cm(range 3-15 cm).Sixty(55.6%)patients underwent handsewn anastomosis and 48(44.4%)were stapled.The median operating time was 3.5 h(range2.0-7.5 h).Sixteen(14.6%)patients had an anastomotic leak.Among these,11 patients required reexploration and five were managed expectantly.The anastomotic leak rate was similar in patients with and without diverting stoma(8/60,13.4%with stoma and 8/48;16.7%without stoma).In 15(13.9%)patients,resection margins were positive for malignancy.Ninteen(17.6%)patients developed anastomotic strictures at a median duration of 8 mo(range 3-20 mo).Among these,15 patients were successfully managed with per-anal dilatation.On multivariate analysis,advance age(>60 years)was the only risk factor for anastomotic leak(P=0.004).On the other hand,anastomotic leak(P=0.00),mucin positive tumor(P =0.021),and lower rectal growth(P=0.011)were found as risk factors for the development of an anastomotic stricture.CONCLUSION:Advance age is a risk factor for an anastomotic leak.An anastomotic leak,a mucin-secreting tumor,and lower rectal growth predispose patients to develop anastomotic strictures.展开更多
Objective To examine the correlation between the health-related quality of life measured by the St.George's Respiratory Questionnaire(SGRQ) and the commonly used physiological measures in lymphangioleiomyomatosis(...Objective To examine the correlation between the health-related quality of life measured by the St.George's Respiratory Questionnaire(SGRQ) and the commonly used physiological measures in lymphangioleiomyomatosis(LAM).Methods This study retrospectively analyzed the SGRQ scores and other measures(the Borg scale of breathlessness at rest,6-minute walking distance,blood oxygen levels,and pulmonary function) of patients diagnosed and confirmed with LAM.Altogether 38 patients between June 2007 and November 2009 were included.Results The mean values of the SGRQ three components(symptoms,activity,and impacts) and total scores in the LAM patients were 46.95±28.90,58.47±25.41,47.89±29.66,and 51.11±26.35,respectively.The SGRQ total or component scores were correlated well with the Borg scale of breathlessness,6-minute walking distance,partial pressure of oxygen in arterial blood,spirometry and diffusion capacity of lung.There were poor correlations between SGRQ score and residual volume or total lung capacity.In our preliminary observation,sirolimus improved the SGRQ total and three component scores and the Borg scale of breathlessness significantly after 101-200 days of treatment(n=6).Conclusions The SGRQ score in LAM is correlated well with physiological measures(Borg scale of breathlessness,6-minute walking distance,blood oxygen levels,and pulmonary function tests).The SGRQ could therefore be recommended in baseline and follow-up evaluation of patients with LAM.Treatment with sirolimus,an inhibitor of mammalian target of rapamycin,may improve the quality of life and patient's perception of breathlessness in LAM.展开更多
We use molecular dynamics (MD) simulations to study the effects of vacancies on tube diameters and interwall spacings of multi-walled carbon nanotubes (MWCNTs). Two types of vacancies, double vacancy and three danglin...We use molecular dynamics (MD) simulations to study the effects of vacancies on tube diameters and interwall spacings of multi-walled carbon nanotubes (MWCNTs). Two types of vacancies, double vacancy and three dangling-bond (3DB) single vacancy, are identified to have opposite effects on the tube size change, which explains the inconsistency of the experimentally measured interwall spacings of MWCNTs after electron beam irradiation. A theoretical model to quantitatively predict the shrunk structures of the irradiated MWCNTs is further developed. We also discuss the fabrications of prestressed MWCNTs, in which reduced interwall spacings are desired to enhance the overall elastic modulus and strength.展开更多
Based on the analysis of developing target, function and constitution of research projects system for remote management, the virtual account system is established on 3 layers of B/S mode. The development process of vi...Based on the analysis of developing target, function and constitution of research projects system for remote management, the virtual account system is established on 3 layers of B/S mode. The development process of virtual account system is realized by JSP/Servlets development language and MySQL database under windows server 2003 platform. At the same time, network security module of the system has been realized to reduce the influence caused by network security incidents. The system is capable of updating the information of vertical and horizontal projects dynamically and assigning virtual funds on WWW. Also, it realizes the query, statistical analysis function and so on. Practical results show that the system is a successful system for analyzing the various projects index of different departments.展开更多
The audit expectation gap is critical to the auditing profession because the greater the unfulfilled expectations from the public, the lower is the credibility, earning potential and prestige associated with the work...The audit expectation gap is critical to the auditing profession because the greater the unfulfilled expectations from the public, the lower is the credibility, earning potential and prestige associated with the work of auditors. The aim of this paper is to uncover the causes of an audit expectation gap. It is revealed that the existence of an audit expectation gap is due to complicated nature of an audit function; conflicting role of auditors; retrospective evaluation of auditors＇ performance; time lag in responding to changing expectation; and self-regulation process of the auditing profession.展开更多
This paper introduces the origin of Inclusive Financial System, summarizes the basic theories and views on inclusive financial system development and poverty reduction from experts and scholars at home and abroad. The...This paper introduces the origin of Inclusive Financial System, summarizes the basic theories and views on inclusive financial system development and poverty reduction from experts and scholars at home and abroad. The paper establishes a theoretical analysis framework which impacts poor family income gap by using exponential smoothing method. The government should improve the credit market in poverty- stricken area by the way of macro-management to establish inclusive financial system, to overcome the difficulty of poor farmers＇ credit, to make more poor families to obtain credit opportunities.展开更多
In a large-volume,high-density traffic background,air traffic manifests fluid-like microscopical characteristics.The characteristics are formed by the micro tailing actions between individual aircraft.Aircraft headway...In a large-volume,high-density traffic background,air traffic manifests fluid-like microscopical characteristics.The characteristics are formed by the micro tailing actions between individual aircraft.Aircraft headway refers to the time interval between successive flying aircraft in air traffic flow,which is one of the most important characteristics of air traffic flow.The variation in aircraft headway reveals the air traffic control behaviour.In this paper,we study the characteristics of air traffic control behaviours by analyzing radar tracks in a terminal maneuvering area.The headway in arrival traffic flow is measured after the determination of aircraft trailing relationships.The headway evolutionary characteristics for different control decisions and the headway evolutionary characteristics in different phase-states are discussed,and some interesting findings are gotten.This work may be helpful for scholars and managers in understanding the intrinsic nature of air traffic flow and in the development of intelligent assistant decision systems for air traffic management.展开更多
Light detection and ranging (LIDAR) based on time of flight (TOF) method is widely used in many fields related to distance measurement. LIDAR generally uses laser diode (LD) to emit the pulsed laser with high peak pow...Light detection and ranging (LIDAR) based on time of flight (TOF) method is widely used in many fields related to distance measurement. LIDAR generally uses laser diode (LD) to emit the pulsed laser with high peak power and short duration to ensure a large distance measurement range and eye safety. To achieve this goal, we propose a pulsed LD drive method producing the drive current with high peak and narrow pulse width. We analyze the key issues and related theories of the drive current generation based on this method and design an LD driver. A model of drive current generation is established and the influence of operating frequency on drive current is discussed. The LD driver is simulated by software and verified by experiments. The working frequency of the driver changes from 20 kHz to 100 kHz and the charging voltage is set at 130 V. The current produced by this driver has a duration of 8.8 ns and a peak of about 35 A, and the peak output optical power of the LD exceeds 75 W.展开更多
Till now a laser rangefinder has been used to find the range of a stationary target or the variations and deformities of a plane surface like in the manufacturing processes.New concept in the design of a laser rangefi...Till now a laser rangefinder has been used to find the range of a stationary target or the variations and deformities of a plane surface like in the manufacturing processes.New concept in the design of a laser rangefinder for a moving target is described.It is based on triangulation method of ranging and combines with a threefold false target rejection circuit to eliminate the possibility of false target indication due to light reflected by any obstruction in the line of sight of laser source and the target. The false target rejection is done twice through hardware and once through software.展开更多
Based on blasting demolition of high thin-wall hyperbolic reinforced concrete cool tower, by virtue of engineering practice of blasting the tube concrete structures, the analysis and research were made on the mechanis...Based on blasting demolition of high thin-wall hyperbolic reinforced concrete cool tower, by virtue of engineering practice of blasting the tube concrete structures, the analysis and research were made on the mechanism of cool tower collapse through selecting blasting parameters and selecting gap form, gap size and gap angle. The cool tower was twisted, collapsed directionally and broken well according to the design requirements. The expected results and purposes of blasting were obtained with no back blow, total blasted pile approximates to 4 - 5 m, no occurrence of flying stones and no damage to fixed buildings and equipment, the large-sized hyperbolic thin-wall reinforced concrete cool towers are twisted during blasting and it collapses well with good breaking. The test and measurement of blasting vibrating velocity was carried out during blasting and the measuring results are much less than critical values specified by Safety Regulations for Blasting. The study shows that gap form, gap size and gap angle are the key factors to cool tower collapse and will give beneficial references to related theoretical study and field application.展开更多
Objective To evaluate the role of open reduction through anterior-medial malleolar approachwith cannulated screw internal fixation in the treatment of displaced talus fractures. Methods 16 cases of Hawkin type Ⅱ - Ⅲ...Objective To evaluate the role of open reduction through anterior-medial malleolar approachwith cannulated screw internal fixation in the treatment of displaced talus fractures. Methods 16 cases of Hawkin type Ⅱ - Ⅲ displaced talus fractures were treated by open reduction through single anterior medial malleolar approach with cannulated screw internal fixation. Results All the 16 cases of displaced talus fractures achieved bony heal in which 5 cases suffered talus aseptic necrosis. The whole excellence-good ratio reached 62. 5%. Conclusion Open reduction through anterior-medial malleolar approach with cannulated screw internal fixation is a less trauma, easy manipulation, effective method of treatment for displaced talus fractures.展开更多
Lateral process fractures of talus are rare injuries with a potential to cause significant morbidity if misdiagnosed. The appropriate management of these fractures is still controversial and only a few reports are ava...Lateral process fractures of talus are rare injuries with a potential to cause significant morbidity if misdiagnosed. The appropriate management of these fractures is still controversial and only a few reports are available on this subject. We presented a case of a 37-year-old male with neglected fracture on the lateral process of talus which was misdiagnosed at the time of injury. The patient presented to 7 months after misdiagnosis with a chronic ankle pain. Our case is unique in the sense that it is a rare case of neglected fracture on the lateral process of taluswhich presented as a loose body in sinus tarsi. However, a surgery with an excision of the loose body presented a satisfactory outcome along with 2 years＇ follow-up. To our knowledge, it ought to he the first case reported in the English literature. Through this case report, we highlight the importance of high index of suspicion for such rare bony injuries while evaluating trauma to the lateral side of ankle and discuss the principles of management of these fractures.展开更多
Based on data for 2005 to 2012, an analysis of the compensation gap between top executives at different Chinese listed companies reveals the following conclusions. （1） The large compensation gap existing among execu...Based on data for 2005 to 2012, an analysis of the compensation gap between top executives at different Chinese listed companies reveals the following conclusions. （1） The large compensation gap existing among executives at listed Chinese companies--in some years even larger than that between rank-and-file employees--is mainly caused by the exorbitant executive compensation at a minority of companies. （2） Between 2005 and 2012, the compensation gap first widened dramatically and then diminished gradually. The leading factor in this fluctuation was the drastic rise and fall in the level of executive compensation at a handful of financial enterprises. The main reason for the narrowing of the compensation gap is central government regulation, which has helped to curb the excessive growth of executive compensation in society as a whole. （3） Even in the same round of fluctuation, state-owned listed companies differ markedly from non-state-owned listed companies in the way their executive compensation is decided. （4） State-owned listed companies＇ executive compensation strategies and their internal governance structure have not played their due role in moderating the overly rapid growth of their executives＇ compensation or in reducing the compensation gap.展开更多
Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the unifo...Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the uniformity of the phase change material （PCM） temperature distribution. Thus, a novel non-equidistant helical-coil structure was proposed in this study. Its coil pitch decreased along the flow direction of heat transfer fluid, which made the heat exchange area in unit volume increase to match the decreasing temperature difference between the heat transfer fluid and PCM. The structure was optimized using numerical simulation. An experimental system was developed and the experiment results indicated that the proposed non-equidistant helical-coil heat accumulator was more effective than equidistant helical-coil for latent heat storage. The uniformity of the temperaalre distribution was also confirmed by simulation results.展开更多
High-quality carbon nanotubes （CNTs） are promising materials in many applications. However, current chemical vapor deposition （CVD） methods for CNT synthesis suffer from the discrepancy between the quality and yie...High-quality carbon nanotubes （CNTs） are promising materials in many applications. However, current chemical vapor deposition （CVD） methods for CNT synthesis suffer from the discrepancy between the quality and yield of CNTs： Low-quality CNTs can be synthesized with high yield, while high-quality CNTs can only be synthesized with low yield. Here a CVD method has been designed to synthesize both high-quality and low-quality CNTs using the same combination of catalyst and precursor. As a result, we were able to understand the reasons for the low yield in high-quality CNT synthesis and a method was derived to improve their yield. This understanding is an important step towards high- yield synthesis of high-quality CNTs.展开更多
For most countries of the world theaccession of another country to the WTO isnothing terrific.Similarly,for the WTO itselfthe addition of a new member is quite acommon occurrence.However,China'saccession to the WT...For most countries of the world theaccession of another country to the WTO isnothing terrific.Similarly,for the WTO itselfthe addition of a new member is quite acommon occurrence.However,China'saccession to the WTO was an event of greatimportance for China itself,for othermembers of the WTO,and even for theeconomy of the whole world.展开更多
基金This study is supported financially by the National Natural Science Foundation of China (Nos.51179179 and 51239008)
文摘The vortex-induced vibration of two identical rigidly mounted risers in a parallel arrangement was studied using Ansys-CFX and model tests.The vortex shedding and force were recorded to determine the effect of spacing on the two-degree-of-freedom oscillation of the risers.CFX was used to study the single riser and two parallel risers in 2–8D spacing considering the coupling effect.Because of the limited width of water channel,only three different riser spacings,2D,3D,and 4D,were tested to validate the characteristics of the two parallel risers by comparing to the numerical simulation.The results indicate that the lift force changes significantly with the increase in spacing,and in the case of 3D spacing,the lift force of the two parallel risers reaches the maximum.The vortex shedding of the risers in 3D spacing shows that a variable velocity field with the same frequency as the vortex shedding is generated in the overlapped area,thus equalizing the period of drag force to that of lift force.It can be concluded that the interaction between the two parallel risers is significant when the risers are brought to a small distance between them because the trajectory of riser changes from oval to curve 8 as the spacing is increased.The phase difference of lift force between the two risers is also different as the spacing changes.
文摘AIM:To determine the incidence and factors responsible for anastomotic leaks and stricture following anterior resection(AR)and its subsequent management.METHODS:Retrospective analysis of data from 108 patients with rectal carcinoma who underwent AR or low anterior resection(LAR)to identify the various preoperative,operative,and post operative factors that might have influence on anastomotic leaks and strictures.RESULTS:There were 68 males and 40 females with an average of 47 years(range 21-75 years).The median distance of the tumor from the anal verge was 8 cm(range 3-15 cm).Sixty(55.6%)patients underwent handsewn anastomosis and 48(44.4%)were stapled.The median operating time was 3.5 h(range2.0-7.5 h).Sixteen(14.6%)patients had an anastomotic leak.Among these,11 patients required reexploration and five were managed expectantly.The anastomotic leak rate was similar in patients with and without diverting stoma(8/60,13.4%with stoma and 8/48;16.7%without stoma).In 15(13.9%)patients,resection margins were positive for malignancy.Ninteen(17.6%)patients developed anastomotic strictures at a median duration of 8 mo(range 3-20 mo).Among these,15 patients were successfully managed with per-anal dilatation.On multivariate analysis,advance age(>60 years)was the only risk factor for anastomotic leak(P=0.004).On the other hand,anastomotic leak(P=0.00),mucin positive tumor(P =0.021),and lower rectal growth(P=0.011)were found as risk factors for the development of an anastomotic stricture.CONCLUSION:Advance age is a risk factor for an anastomotic leak.An anastomotic leak,a mucin-secreting tumor,and lower rectal growth predispose patients to develop anastomotic strictures.
基金Supported by National Basic Research Program of China (973 Program) (2009CB522106)
文摘Objective To examine the correlation between the health-related quality of life measured by the St.George's Respiratory Questionnaire(SGRQ) and the commonly used physiological measures in lymphangioleiomyomatosis(LAM).Methods This study retrospectively analyzed the SGRQ scores and other measures(the Borg scale of breathlessness at rest,6-minute walking distance,blood oxygen levels,and pulmonary function) of patients diagnosed and confirmed with LAM.Altogether 38 patients between June 2007 and November 2009 were included.Results The mean values of the SGRQ three components(symptoms,activity,and impacts) and total scores in the LAM patients were 46.95±28.90,58.47±25.41,47.89±29.66,and 51.11±26.35,respectively.The SGRQ total or component scores were correlated well with the Borg scale of breathlessness,6-minute walking distance,partial pressure of oxygen in arterial blood,spirometry and diffusion capacity of lung.There were poor correlations between SGRQ score and residual volume or total lung capacity.In our preliminary observation,sirolimus improved the SGRQ total and three component scores and the Borg scale of breathlessness significantly after 101-200 days of treatment(n=6).Conclusions The SGRQ score in LAM is correlated well with physiological measures(Borg scale of breathlessness,6-minute walking distance,blood oxygen levels,and pulmonary function tests).The SGRQ could therefore be recommended in baseline and follow-up evaluation of patients with LAM.Treatment with sirolimus,an inhibitor of mammalian target of rapamycin,may improve the quality of life and patient's perception of breathlessness in LAM.
基金Project supported by the National Basic Research Program (973) of China (No 2007CB936803)the National High-Tech R&D Program (863) of China (No 2008AA03Z302)+1 种基金the National Natural Science Foundation of China (No 10832005)the Joint Research Scheme of the National Natural Science Foundation of China and Research Grants Council of Hong Kong (No 50518003)
文摘We use molecular dynamics (MD) simulations to study the effects of vacancies on tube diameters and interwall spacings of multi-walled carbon nanotubes (MWCNTs). Two types of vacancies, double vacancy and three dangling-bond (3DB) single vacancy, are identified to have opposite effects on the tube size change, which explains the inconsistency of the experimentally measured interwall spacings of MWCNTs after electron beam irradiation. A theoretical model to quantitatively predict the shrunk structures of the irradiated MWCNTs is further developed. We also discuss the fabrications of prestressed MWCNTs, in which reduced interwall spacings are desired to enhance the overall elastic modulus and strength.
基金This work is supported by Liaoning Province Doctoral Startup Grant 20031069 and China National "863"CI MS Foundation ( NO2003AA412030 9 ,2004AA412020 08)
文摘Based on the analysis of developing target, function and constitution of research projects system for remote management, the virtual account system is established on 3 layers of B/S mode. The development process of virtual account system is realized by JSP/Servlets development language and MySQL database under windows server 2003 platform. At the same time, network security module of the system has been realized to reduce the influence caused by network security incidents. The system is capable of updating the information of vertical and horizontal projects dynamically and assigning virtual funds on WWW. Also, it realizes the query, statistical analysis function and so on. Practical results show that the system is a successful system for analyzing the various projects index of different departments.
文摘The audit expectation gap is critical to the auditing profession because the greater the unfulfilled expectations from the public, the lower is the credibility, earning potential and prestige associated with the work of auditors. The aim of this paper is to uncover the causes of an audit expectation gap. It is revealed that the existence of an audit expectation gap is due to complicated nature of an audit function; conflicting role of auditors; retrospective evaluation of auditors＇ performance; time lag in responding to changing expectation; and self-regulation process of the auditing profession.
文摘This paper introduces the origin of Inclusive Financial System, summarizes the basic theories and views on inclusive financial system development and poverty reduction from experts and scholars at home and abroad. The paper establishes a theoretical analysis framework which impacts poor family income gap by using exponential smoothing method. The government should improve the credit market in poverty- stricken area by the way of macro-management to establish inclusive financial system, to overcome the difficulty of poor farmers＇ credit, to make more poor families to obtain credit opportunities.
基金supported by the National Nature Science Foundation of China(No.71801215)the Fundamental Research Fund for the Central Universities (No. 3122016C009).
文摘In a large-volume,high-density traffic background,air traffic manifests fluid-like microscopical characteristics.The characteristics are formed by the micro tailing actions between individual aircraft.Aircraft headway refers to the time interval between successive flying aircraft in air traffic flow,which is one of the most important characteristics of air traffic flow.The variation in aircraft headway reveals the air traffic control behaviour.In this paper,we study the characteristics of air traffic control behaviours by analyzing radar tracks in a terminal maneuvering area.The headway in arrival traffic flow is measured after the determination of aircraft trailing relationships.The headway evolutionary characteristics for different control decisions and the headway evolutionary characteristics in different phase-states are discussed,and some interesting findings are gotten.This work may be helpful for scholars and managers in understanding the intrinsic nature of air traffic flow and in the development of intelligent assistant decision systems for air traffic management.
基金National Key Research and Development Plan(No.2017YFF0204800)Natural Science Foundation of Tianjin(No.17JCQNJC01100)+3 种基金National Natural Science Foundation of China(Nos.61501319,51775377,61505140)Young Elite Scientists Sponsorship Program by Cast of China(No.2016QNRC001)Open Project of Key Laboratory of Micro Opto-electro Mechanical System Technology(No.MOMST2015-7)Open Project from Photoelectric Information and Instrument-Engineering Research Center of Beijing,Tianjin University,Ministry of Education(No.GD2015007)
文摘Light detection and ranging (LIDAR) based on time of flight (TOF) method is widely used in many fields related to distance measurement. LIDAR generally uses laser diode (LD) to emit the pulsed laser with high peak power and short duration to ensure a large distance measurement range and eye safety. To achieve this goal, we propose a pulsed LD drive method producing the drive current with high peak and narrow pulse width. We analyze the key issues and related theories of the drive current generation based on this method and design an LD driver. A model of drive current generation is established and the influence of operating frequency on drive current is discussed. The LD driver is simulated by software and verified by experiments. The working frequency of the driver changes from 20 kHz to 100 kHz and the charging voltage is set at 130 V. The current produced by this driver has a duration of 8.8 ns and a peak of about 35 A, and the peak output optical power of the LD exceeds 75 W.
文摘Till now a laser rangefinder has been used to find the range of a stationary target or the variations and deformities of a plane surface like in the manufacturing processes.New concept in the design of a laser rangefinder for a moving target is described.It is based on triangulation method of ranging and combines with a threefold false target rejection circuit to eliminate the possibility of false target indication due to light reflected by any obstruction in the line of sight of laser source and the target. The false target rejection is done twice through hardware and once through software.
文摘Based on blasting demolition of high thin-wall hyperbolic reinforced concrete cool tower, by virtue of engineering practice of blasting the tube concrete structures, the analysis and research were made on the mechanism of cool tower collapse through selecting blasting parameters and selecting gap form, gap size and gap angle. The cool tower was twisted, collapsed directionally and broken well according to the design requirements. The expected results and purposes of blasting were obtained with no back blow, total blasted pile approximates to 4 - 5 m, no occurrence of flying stones and no damage to fixed buildings and equipment, the large-sized hyperbolic thin-wall reinforced concrete cool towers are twisted during blasting and it collapses well with good breaking. The test and measurement of blasting vibrating velocity was carried out during blasting and the measuring results are much less than critical values specified by Safety Regulations for Blasting. The study shows that gap form, gap size and gap angle are the key factors to cool tower collapse and will give beneficial references to related theoretical study and field application.
文摘Objective To evaluate the role of open reduction through anterior-medial malleolar approachwith cannulated screw internal fixation in the treatment of displaced talus fractures. Methods 16 cases of Hawkin type Ⅱ - Ⅲ displaced talus fractures were treated by open reduction through single anterior medial malleolar approach with cannulated screw internal fixation. Results All the 16 cases of displaced talus fractures achieved bony heal in which 5 cases suffered talus aseptic necrosis. The whole excellence-good ratio reached 62. 5%. Conclusion Open reduction through anterior-medial malleolar approach with cannulated screw internal fixation is a less trauma, easy manipulation, effective method of treatment for displaced talus fractures.
文摘Lateral process fractures of talus are rare injuries with a potential to cause significant morbidity if misdiagnosed. The appropriate management of these fractures is still controversial and only a few reports are available on this subject. We presented a case of a 37-year-old male with neglected fracture on the lateral process of talus which was misdiagnosed at the time of injury. The patient presented to 7 months after misdiagnosis with a chronic ankle pain. Our case is unique in the sense that it is a rare case of neglected fracture on the lateral process of taluswhich presented as a loose body in sinus tarsi. However, a surgery with an excision of the loose body presented a satisfactory outcome along with 2 years＇ follow-up. To our knowledge, it ought to he the first case reported in the English literature. Through this case report, we highlight the importance of high index of suspicion for such rare bony injuries while evaluating trauma to the lateral side of ankle and discuss the principles of management of these fractures.
基金supported by Ministry of Education as a major project in philosophy and social sciences(11JZD015,12JZD030)the Special Fund for Basic Research at Central Universities(2012CXQT11,310400086)
文摘Based on data for 2005 to 2012, an analysis of the compensation gap between top executives at different Chinese listed companies reveals the following conclusions. （1） The large compensation gap existing among executives at listed Chinese companies--in some years even larger than that between rank-and-file employees--is mainly caused by the exorbitant executive compensation at a minority of companies. （2） Between 2005 and 2012, the compensation gap first widened dramatically and then diminished gradually. The leading factor in this fluctuation was the drastic rise and fall in the level of executive compensation at a handful of financial enterprises. The main reason for the narrowing of the compensation gap is central government regulation, which has helped to curb the excessive growth of executive compensation in society as a whole. （3） Even in the same round of fluctuation, state-owned listed companies differ markedly from non-state-owned listed companies in the way their executive compensation is decided. （4） State-owned listed companies＇ executive compensation strategies and their internal governance structure have not played their due role in moderating the overly rapid growth of their executives＇ compensation or in reducing the compensation gap.
基金supported by the National Natural Science Foundation of China(Grant No.51576187)Fundamental Research Funds for the Central Universities(Grant No.WK2090130016)
文摘Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the uniformity of the phase change material （PCM） temperature distribution. Thus, a novel non-equidistant helical-coil structure was proposed in this study. Its coil pitch decreased along the flow direction of heat transfer fluid, which made the heat exchange area in unit volume increase to match the decreasing temperature difference between the heat transfer fluid and PCM. The structure was optimized using numerical simulation. An experimental system was developed and the experiment results indicated that the proposed non-equidistant helical-coil heat accumulator was more effective than equidistant helical-coil for latent heat storage. The uniformity of the temperaalre distribution was also confirmed by simulation results.
文摘High-quality carbon nanotubes （CNTs） are promising materials in many applications. However, current chemical vapor deposition （CVD） methods for CNT synthesis suffer from the discrepancy between the quality and yield of CNTs： Low-quality CNTs can be synthesized with high yield, while high-quality CNTs can only be synthesized with low yield. Here a CVD method has been designed to synthesize both high-quality and low-quality CNTs using the same combination of catalyst and precursor. As a result, we were able to understand the reasons for the low yield in high-quality CNT synthesis and a method was derived to improve their yield. This understanding is an important step towards high- yield synthesis of high-quality CNTs.
文摘For most countries of the world theaccession of another country to the WTO isnothing terrific.Similarly,for the WTO itselfthe addition of a new member is quite acommon occurrence.However,China'saccession to the WTO was an event of greatimportance for China itself,for othermembers of the WTO,and even for theeconomy of the whole world.
