Vessels with semi-closed tanks(i.e.,well docks)are widely applied in the military operation and maritime engineer-ing.The water is bound by the semi-closed floating tank and forced by both the incident waves and ship...Vessels with semi-closed tanks(i.e.,well docks)are widely applied in the military operation and maritime engineer-ing.The water is bound by the semi-closed floating tank and forced by both the incident waves and ship’s motions.The free surface oscillations inside the flooded well dock is thus distinctive and very complicated.So far,the natural modes of semi-closed floating tanks have not yet been studied.This paper investigates the characteristics of natural modes of a floating semi-closed tank by combining a mode-resolving model based on mild-slope equations and a hydrodynamic model based on computational fluid dynamics.Results show that the first three natural periods(i.e.,74,23.6,and 14 s)of the tank fall into the band of swell and infragravity waves and they could be triggered under certain circumstance.Multi-period free surface oscillations are observed inside the tank,including the longest natural period(i.e.,74 s),though the incident waves are monochromatic.A possible generation mechanism for the long-period mode is explained on the basis of liquid sloshing and harbor oscillations.Moreover,a long-period component with a period close to the natural mode of well dock is observed in the ship motions,which is generated by the interaction between the waves and ship.展开更多
Heteroatom-doped meso/micro-porous carbon materials are conventionally produced by harsh carbonization under an inert atmosphere involving specific precursors,hard/soft templates,and heteroatom-containing agents.Herei...Heteroatom-doped meso/micro-porous carbon materials are conventionally produced by harsh carbonization under an inert atmosphere involving specific precursors,hard/soft templates,and heteroatom-containing agents.Herein,we report a facile synthesis of N and O co-doped meso/micro-porous carbon(NOMC)by template-free carbonization of a small-molecule precursor in a semi-closed system.The semi-closed carbonizaiton process yields hydrophilic NOMCs with large surface area in a high yield.The porous structure as well as the elemental composition of NOMCs can be modulated by changing the holding time at a particular temperature.NOMCs as metal-free heterogeneous catalysts can selectively oxidize benzyl alcohol and its derivatives into aldehydes/ketones with>85%conversion in aqueous solution,which is much higher than that of the control sample obtained in tube furnace(21%conversion),mainly due to their high N content,high percentage of pyridinic N,and large surface area.The presence of O-containing moieties also helps to improve the hydrophilicity and dispersion ability of catalysts and thus facilitates the mass transfer process during aqueous oxidation.The NOMC catalysts also dispayed excellent activity for a wide range of substrates with a selectivity of>99%.展开更多
A preliminary study on the distribution of sediment transport and siltation within a semi-closed harbour as well as the factors affecting the siltation has been made with a suspended sediment model, in which the Liany...A preliminary study on the distribution of sediment transport and siltation within a semi-closed harbour as well as the factors affecting the siltation has been made with a suspended sediment model, in which the Lianyungang port is used as the prototype. Based on the work, this paper describes a tubid water experiment within a typical excavated harbour basin. According to the experimental results some expressions for predicting the average siltation amount for semi-closed harbour basins by means of dimensional analysis have been proposed, with tidal features, harbour geometry and properties of sediment taken into account. Through comparing the calculated results with the laboratory and field measured data, it has been shown that the expressions presented in this paper are reasonable.展开更多
Objective: To compare a new device (Innocor) for non-invasive measurement of cardiac output (CO) by foreign gas rebreathing method with conventional techniques used in the measurements of cardiac function. Methods: Ca...Objective: To compare a new device (Innocor) for non-invasive measurement of cardiac output (CO) by foreign gas rebreathing method with conventional techniques used in the measurements of cardiac function. Methods: Cardiac outputs measured by Innocor (CORB) were compared with CO obtained by echocardiography (COEC), Swan-Ganz thermodilution (COTD), and left ventricle radiography (COLVR) in 34 patients subjected to cardiac catheterization. Values obtained from the four methods were analyzed by linear regression and paired values were compared by the method of Bland and Altman in SPSS. Results: There was strong positive correlation (r=0.94) between Innocor cardiac output values and the corresponding values obtained by ther-modilution and between COEC and COLVR values. Thermodilution appears to overestimate cardiac output when compared to the values obtained with Innocor by (0.66±0.22) L/min (P<0.0001). There was no correlation between data obtained by Innocor and the corresponding COEC and COLVR values. Conclusion: Innocor CORB is an easy, safe and well established method for non-invasive measurement of cardiac output with good prospects for clinical application in heart disease patients.展开更多
目的比较经典式原位肝移植手术对CO2部分重吸入法和持续温度稀释法测定心排血量(CO)的影响。方法行经典式原位肝移植手术患者14例,于手术探查,门静脉阻断即刻和阻断后15、30 m in,开放即刻和开放后15、30、60 m in各时间点,分别用CO2部...目的比较经典式原位肝移植手术对CO2部分重吸入法和持续温度稀释法测定心排血量(CO)的影响。方法行经典式原位肝移植手术患者14例,于手术探查,门静脉阻断即刻和阻断后15、30 m in,开放即刻和开放后15、30、60 m in各时间点,分别用CO2部分重吸入法和持续温度稀释法测定CO(RBCO和TDCO),将结果进行比较。结果RBCO和TDCO在门静脉阻断后都呈下降趋势,最低值出现于阻断15 m in时,开放后则明显升高,TDCO的升幅大于RBCO,并一直处于上升趋势中,而RBCO在开放15 m in时有一回落。除开放15 m in时间点以外,各时间点RBCO均显著低于TDCO(P<0.01)。各时间点TDCO与RBCO的相关性检验均有统计学意义(P<0.001)。结论在经典式原位肝移植手术中,CO2部分重吸入法所测得的CO普遍低于持续温度稀释法所测值,但发展趋势相似,两者之间相关性良好。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51979029)。
文摘Vessels with semi-closed tanks(i.e.,well docks)are widely applied in the military operation and maritime engineer-ing.The water is bound by the semi-closed floating tank and forced by both the incident waves and ship’s motions.The free surface oscillations inside the flooded well dock is thus distinctive and very complicated.So far,the natural modes of semi-closed floating tanks have not yet been studied.This paper investigates the characteristics of natural modes of a floating semi-closed tank by combining a mode-resolving model based on mild-slope equations and a hydrodynamic model based on computational fluid dynamics.Results show that the first three natural periods(i.e.,74,23.6,and 14 s)of the tank fall into the band of swell and infragravity waves and they could be triggered under certain circumstance.Multi-period free surface oscillations are observed inside the tank,including the longest natural period(i.e.,74 s),though the incident waves are monochromatic.A possible generation mechanism for the long-period mode is explained on the basis of liquid sloshing and harbor oscillations.Moreover,a long-period component with a period close to the natural mode of well dock is observed in the ship motions,which is generated by the interaction between the waves and ship.
基金supported by National Natural Science Foundation of China(Grant No.51772089 and 21872046)the Youth 1000 Talent Program of China+3 种基金the Outstanding Youth Scientist Foundation of Hunan Province(Grant No.2018JJ1009)the Natural Science Foundation of Hunan Province(Grant No.2020JJ4174)Provincial Science and Technology Innovation Platform and Talent Plan-Changsha,Zhuzhou and Xiangtan High-level Talents Accumulation Project(Grant No.2017XK2023)Research and Development Plan of Key Areas in Hunan Province(Grant No.2019GK2235)
文摘Heteroatom-doped meso/micro-porous carbon materials are conventionally produced by harsh carbonization under an inert atmosphere involving specific precursors,hard/soft templates,and heteroatom-containing agents.Herein,we report a facile synthesis of N and O co-doped meso/micro-porous carbon(NOMC)by template-free carbonization of a small-molecule precursor in a semi-closed system.The semi-closed carbonizaiton process yields hydrophilic NOMCs with large surface area in a high yield.The porous structure as well as the elemental composition of NOMCs can be modulated by changing the holding time at a particular temperature.NOMCs as metal-free heterogeneous catalysts can selectively oxidize benzyl alcohol and its derivatives into aldehydes/ketones with>85%conversion in aqueous solution,which is much higher than that of the control sample obtained in tube furnace(21%conversion),mainly due to their high N content,high percentage of pyridinic N,and large surface area.The presence of O-containing moieties also helps to improve the hydrophilicity and dispersion ability of catalysts and thus facilitates the mass transfer process during aqueous oxidation.The NOMC catalysts also dispayed excellent activity for a wide range of substrates with a selectivity of>99%.
文摘A preliminary study on the distribution of sediment transport and siltation within a semi-closed harbour as well as the factors affecting the siltation has been made with a suspended sediment model, in which the Lianyungang port is used as the prototype. Based on the work, this paper describes a tubid water experiment within a typical excavated harbour basin. According to the experimental results some expressions for predicting the average siltation amount for semi-closed harbour basins by means of dimensional analysis have been proposed, with tidal features, harbour geometry and properties of sediment taken into account. Through comparing the calculated results with the laboratory and field measured data, it has been shown that the expressions presented in this paper are reasonable.
文摘Objective: To compare a new device (Innocor) for non-invasive measurement of cardiac output (CO) by foreign gas rebreathing method with conventional techniques used in the measurements of cardiac function. Methods: Cardiac outputs measured by Innocor (CORB) were compared with CO obtained by echocardiography (COEC), Swan-Ganz thermodilution (COTD), and left ventricle radiography (COLVR) in 34 patients subjected to cardiac catheterization. Values obtained from the four methods were analyzed by linear regression and paired values were compared by the method of Bland and Altman in SPSS. Results: There was strong positive correlation (r=0.94) between Innocor cardiac output values and the corresponding values obtained by ther-modilution and between COEC and COLVR values. Thermodilution appears to overestimate cardiac output when compared to the values obtained with Innocor by (0.66±0.22) L/min (P<0.0001). There was no correlation between data obtained by Innocor and the corresponding COEC and COLVR values. Conclusion: Innocor CORB is an easy, safe and well established method for non-invasive measurement of cardiac output with good prospects for clinical application in heart disease patients.
文摘目的比较经典式原位肝移植手术对CO2部分重吸入法和持续温度稀释法测定心排血量(CO)的影响。方法行经典式原位肝移植手术患者14例,于手术探查,门静脉阻断即刻和阻断后15、30 m in,开放即刻和开放后15、30、60 m in各时间点,分别用CO2部分重吸入法和持续温度稀释法测定CO(RBCO和TDCO),将结果进行比较。结果RBCO和TDCO在门静脉阻断后都呈下降趋势,最低值出现于阻断15 m in时,开放后则明显升高,TDCO的升幅大于RBCO,并一直处于上升趋势中,而RBCO在开放15 m in时有一回落。除开放15 m in时间点以外,各时间点RBCO均显著低于TDCO(P<0.01)。各时间点TDCO与RBCO的相关性检验均有统计学意义(P<0.001)。结论在经典式原位肝移植手术中,CO2部分重吸入法所测得的CO普遍低于持续温度稀释法所测值,但发展趋势相似,两者之间相关性良好。
