目的评价并比较序贯性脏器衰竭评分(sequential organ failure assessment,SOFA)、急性生理学与慢性健康状况评分(acute physiology and chronic health evaluation,APACHE)Ⅱ、简明急性生理学评分(simplified acute physiology score,S...目的评价并比较序贯性脏器衰竭评分(sequential organ failure assessment,SOFA)、急性生理学与慢性健康状况评分(acute physiology and chronic health evaluation,APACHE)Ⅱ、简明急性生理学评分(simplified acute physiology score,SAPS)Ⅱ和Liano评分4种危重病评分系统及RIFLE标准对急性肾损伤(acute kidney injury,AKI)患者的预后评估价值。方法本研究为前瞻性、单中心研究,收集2008年12月到2009年11月复旦大学附属华山医院各种病因引起的AKI患者。AKI的诊断标准为RIFLE的肌酐标准,除外肾后性、肾小球性、肾血管性和间质性肾炎等引起的急性损伤。研究的主要终点是28d死亡率。比较存活组和死亡组的RIFLE分级、SOFA、APACHEⅡ、SAPSⅡ和Liano评分,并进行各种评分系统对死亡的ROC曲线分析,同时将4种评分方法根据RIFLE分级进行分层分析。结果共入选194例符合入选标准的AKI患者。存活组和死亡组的RIFLE分级、AKI病因、是否需要透析差异无统计学意义(P>0.05)。死亡组的机械通气比例、SOFA、APACHEⅡ、SAPSⅡ和Liano评分显著高于存活组(P<0.001)。SOFA、APACHEⅡ、SAPSⅡ和Liano评分预测死亡的受试者工作特性(ROC)曲线下面积分别为0.900、0.885、0.888、0.875(均P<0.001),而RIFLE的ROC曲线下面积为0.566(P>0.05)。按AKI的RIFLE级别进行分层分析时发现,4个评分方法在衰竭组(Fc)ROC曲线下面积最大,其中又以Liano评分最高。结论 RIFLE分级对AKI患者的预后无明显的判断价值,而危重病评分包括SOFA、APACHEⅡ、SAPSⅡ和Liano评分对AKI的预后具有良好的预测价值。展开更多
Aimed at the image detection on the ablation wearing, scrape wearing and rifling angle of the artillery body pipe, the character of the inner surface image of the pipe is discussed, the model for rifling, ablation wea...Aimed at the image detection on the ablation wearing, scrape wearing and rifling angle of the artillery body pipe, the character of the inner surface image of the pipe is discussed, the model for rifling, ablation wearing and scrape wearing is brought up, and a new image operator is proposed for these detection. This operator can detect the rifling angle in a high precision, and tell the ablation wearing from scrape wearing in the image, therefore the degree of ablation wearing and scrape wearing can be detected efficiently. This is useful for the artillery body pipe's producing process and life evaluation.展开更多
目的：研究的主要目的是采用急性透析质量倡议（ADQI）提出的RIFLE分级诊断标准，对影响重症监护室中（intensive care unit,ICU）急性肾损伤的发病率及预后相关的危险因素进行分析。方法：收集2009年7月～2010年4月入住四川大学华西医...目的：研究的主要目的是采用急性透析质量倡议（ADQI）提出的RIFLE分级诊断标准，对影响重症监护室中（intensive care unit,ICU）急性肾损伤的发病率及预后相关的危险因素进行分析。方法：收集2009年7月～2010年4月入住四川大学华西医院重症监护室的患者临床数据资料，总结临床特征、实验室指标及临床预后。结果：共有1036名病人纳入研究，其中发生AKI的患者273例，发病率为26.35％，短期病死率52.38％。Logstic回归分析中，与AKI短期预后相关的因素有：COPD[odds ratio（OR）：0.461）]，SIRS（OR=80.473），手术（OR=0.335），机械通气（OR=2.575），基础肌酐值（OR=2.476）。随RIFLE分级越高，患者的病死率越高，而年龄分组与病死率差异无统计学意义。结论：在ICU中，AKI的预后与多种危险因素有关，RIFLE标准在临床工作中能及早发现AKI，积极干预，采取有效治疗，降低病死率。展开更多
Sources of dispersions that contribute to delivery error and reduce the soldier performance in terms of hit probability are numerous.In order to improve the warfighter performance,the source of the errors contributing...Sources of dispersions that contribute to delivery error and reduce the soldier performance in terms of hit probability are numerous.In order to improve the warfighter performance,the source of the errors contributing to the inaccuracy and dispersion of the weapon systems must be understood.They include ammunition dispersion error,gun dispersion,aerodynamic jump and the aiming error.The aiming error or gun pointing error is defined as the angle between the gun muzzle at the instant the trigger is pulled and the line of fire that corresponds to the intendent aim point.This is a round-to-round error.In weapons systems that include the rifle,the ammunition,a sight and a gunner,the aiming error was shown to be the single most important source of dispersion for the regular infantryman.In other words,for the general purpose rifle weapon system,the weak link is often the human.In order to verify and quantify this assertion,an experimental investigation was carried out to determine the aiming error associated with general purpose rifle fired by infantryman.The aiming error was evaluated for various firing positions and scenarios using infantryman for ranges varying between 100 m and 500 m.The results show that the aiming error is the main contributor to dispersion for the general purpose rifle fired by a non-specialized infantryman.The aiming error induced dispersion for unstressed and rested gunners is shown to be at best equivalent to that of the weapon fired from a bench rest by a marksman.Crown Copyright(?) 2019 Production and hosting by Elsevier B.V.on behalf of China Ordnance Society.展开更多
A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight dis...A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight distribution and layout(e.g.stock length,position of grip and forestock)affect aiming comfort.In the paper,the upper extremity muscle activity was used to characterize the aiming comfort.A human-rifle musculoskeletal model was developed,which was validated by the surface electromyography(EMG)data.The results showed that the design parameters of rifle(weight,distance of gravity center to body and layout)had a significant influence on aiming comfort.The greater the weight was,the stronger the muscle activity was.With the distance increasing,first the muscle activity decreased,and then increased when the distance is exceeding a certain value.In addition,the combined influences of weight and distance illustrated that there was an optimal distance to make the slightest muscle movements for certain weight.For designing a rifle’s layout,more muscular exertions were required to maintain the holding posture with the stock length increasing,which was suggested to be in the range of 0.1 8 m to 0.2 7 m.Results can be used to optimize the ergonomics design of rifle,improving the comfort of the rifle aiming process and the shooting accuracy.展开更多
The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems.Special laboratory stand designed for investigating the recoil process...The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems.Special laboratory stand designed for investigating the recoil process was used.The motion of the rifle was detected by the use of the laser interferometer and the optical camera.The recoil velocity time courses were determined by smoothing and differentiation of experimental position records.The results of the experiments indicated that in the case of an active automatics system two values of the recoil velocity can be used for calculation of the energetic efficiency coefficient:the maximum recoil velocity and the final recoil velocity at the end of the automatics action cycle.The values of the coefficient,calculated using these two values of the recoil velocity,distinctly differ.However,it was shown that their values indicate the same relation between the efficiency of various muzzle brakes.The value of the efficiency coefficient,determined on the basis of the final recoil velocity value,is practically the same as that determined on the basis of the final recoil velocity value for the rifle with an inactive automatics system.展开更多
文摘目的评价并比较序贯性脏器衰竭评分(sequential organ failure assessment,SOFA)、急性生理学与慢性健康状况评分(acute physiology and chronic health evaluation,APACHE)Ⅱ、简明急性生理学评分(simplified acute physiology score,SAPS)Ⅱ和Liano评分4种危重病评分系统及RIFLE标准对急性肾损伤(acute kidney injury,AKI)患者的预后评估价值。方法本研究为前瞻性、单中心研究,收集2008年12月到2009年11月复旦大学附属华山医院各种病因引起的AKI患者。AKI的诊断标准为RIFLE的肌酐标准,除外肾后性、肾小球性、肾血管性和间质性肾炎等引起的急性损伤。研究的主要终点是28d死亡率。比较存活组和死亡组的RIFLE分级、SOFA、APACHEⅡ、SAPSⅡ和Liano评分,并进行各种评分系统对死亡的ROC曲线分析,同时将4种评分方法根据RIFLE分级进行分层分析。结果共入选194例符合入选标准的AKI患者。存活组和死亡组的RIFLE分级、AKI病因、是否需要透析差异无统计学意义(P>0.05)。死亡组的机械通气比例、SOFA、APACHEⅡ、SAPSⅡ和Liano评分显著高于存活组(P<0.001)。SOFA、APACHEⅡ、SAPSⅡ和Liano评分预测死亡的受试者工作特性(ROC)曲线下面积分别为0.900、0.885、0.888、0.875(均P<0.001),而RIFLE的ROC曲线下面积为0.566(P>0.05)。按AKI的RIFLE级别进行分层分析时发现,4个评分方法在衰竭组(Fc)ROC曲线下面积最大,其中又以Liano评分最高。结论 RIFLE分级对AKI患者的预后无明显的判断价值,而危重病评分包括SOFA、APACHEⅡ、SAPSⅡ和Liano评分对AKI的预后具有良好的预测价值。
文摘Aimed at the image detection on the ablation wearing, scrape wearing and rifling angle of the artillery body pipe, the character of the inner surface image of the pipe is discussed, the model for rifling, ablation wearing and scrape wearing is brought up, and a new image operator is proposed for these detection. This operator can detect the rifling angle in a high precision, and tell the ablation wearing from scrape wearing in the image, therefore the degree of ablation wearing and scrape wearing can be detected efficiently. This is useful for the artillery body pipe's producing process and life evaluation.
文摘目的：研究的主要目的是采用急性透析质量倡议（ADQI）提出的RIFLE分级诊断标准，对影响重症监护室中（intensive care unit,ICU）急性肾损伤的发病率及预后相关的危险因素进行分析。方法：收集2009年7月～2010年4月入住四川大学华西医院重症监护室的患者临床数据资料，总结临床特征、实验室指标及临床预后。结果：共有1036名病人纳入研究，其中发生AKI的患者273例，发病率为26.35％，短期病死率52.38％。Logstic回归分析中，与AKI短期预后相关的因素有：COPD[odds ratio（OR）：0.461）]，SIRS（OR=80.473），手术（OR=0.335），机械通气（OR=2.575），基础肌酐值（OR=2.476）。随RIFLE分级越高，患者的病死率越高，而年龄分组与病死率差异无统计学意义。结论：在ICU中，AKI的预后与多种危险因素有关，RIFLE标准在临床工作中能及早发现AKI，积极干预，采取有效治疗，降低病死率。
文摘Sources of dispersions that contribute to delivery error and reduce the soldier performance in terms of hit probability are numerous.In order to improve the warfighter performance,the source of the errors contributing to the inaccuracy and dispersion of the weapon systems must be understood.They include ammunition dispersion error,gun dispersion,aerodynamic jump and the aiming error.The aiming error or gun pointing error is defined as the angle between the gun muzzle at the instant the trigger is pulled and the line of fire that corresponds to the intendent aim point.This is a round-to-round error.In weapons systems that include the rifle,the ammunition,a sight and a gunner,the aiming error was shown to be the single most important source of dispersion for the regular infantryman.In other words,for the general purpose rifle weapon system,the weak link is often the human.In order to verify and quantify this assertion,an experimental investigation was carried out to determine the aiming error associated with general purpose rifle fired by infantryman.The aiming error was evaluated for various firing positions and scenarios using infantryman for ranges varying between 100 m and 500 m.The results show that the aiming error is the main contributor to dispersion for the general purpose rifle fired by a non-specialized infantryman.The aiming error induced dispersion for unstressed and rested gunners is shown to be at best equivalent to that of the weapon fired from a bench rest by a marksman.Crown Copyright(?) 2019 Production and hosting by Elsevier B.V.on behalf of China Ordnance Society.
基金Supported by the National Natural Science Foundation of China(651575279)the Basic Research of National Defense of China(A1020133013)
文摘A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight distribution and layout(e.g.stock length,position of grip and forestock)affect aiming comfort.In the paper,the upper extremity muscle activity was used to characterize the aiming comfort.A human-rifle musculoskeletal model was developed,which was validated by the surface electromyography(EMG)data.The results showed that the design parameters of rifle(weight,distance of gravity center to body and layout)had a significant influence on aiming comfort.The greater the weight was,the stronger the muscle activity was.With the distance increasing,first the muscle activity decreased,and then increased when the distance is exceeding a certain value.In addition,the combined influences of weight and distance illustrated that there was an optimal distance to make the slightest muscle movements for certain weight.For designing a rifle’s layout,more muscular exertions were required to maintain the holding posture with the stock length increasing,which was suggested to be in the range of 0.1 8 m to 0.2 7 m.Results can be used to optimize the ergonomics design of rifle,improving the comfort of the rifle aiming process and the shooting accuracy.
基金supported by the National Research Centre[grant number DOBR/0046/R/ID1/2012/03]。
文摘The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems.Special laboratory stand designed for investigating the recoil process was used.The motion of the rifle was detected by the use of the laser interferometer and the optical camera.The recoil velocity time courses were determined by smoothing and differentiation of experimental position records.The results of the experiments indicated that in the case of an active automatics system two values of the recoil velocity can be used for calculation of the energetic efficiency coefficient:the maximum recoil velocity and the final recoil velocity at the end of the automatics action cycle.The values of the coefficient,calculated using these two values of the recoil velocity,distinctly differ.However,it was shown that their values indicate the same relation between the efficiency of various muzzle brakes.The value of the efficiency coefficient,determined on the basis of the final recoil velocity value,is practically the same as that determined on the basis of the final recoil velocity value for the rifle with an inactive automatics system.
