The AZ91 D magnesium alloy containing rare earth Gd was prepared in this study, and the effect of semi-solid isothermal heat treatment on the microstructure of the alloy was investigated to obtain an optimum semi-soli...The AZ91 D magnesium alloy containing rare earth Gd was prepared in this study, and the effect of semi-solid isothermal heat treatment on the microstructure of the alloy was investigated to obtain an optimum semi-solid structure. Results show that Gd can refine the microstructure of AZ91 D magnesium alloy, and the optimum semi-solid AZ91 D microstructure can be achieved by adding 1.5wt.% Gd. After treated at 585 °C for 30 min, the well distributed rose-shaped and near-spherical semi-solid microstructures of AZ91D+1.5wt.%Gd alloy can be obtained. The liquid phase of the semi-solid alloy consists of three components, namely, the molten pool, the "entrapped liquid" pool and the liner liquid film which separates two neighbor particles. The solid phase is composed of two phases, the primary α-Mg particles and the α-Mg phase formed in the second stage of solidification. With the increase of holding time, melting which causes the decrease of the primary α-Mg particle size is the dominant mechanism in the initial stage while coalescence and Ostwald ripening tend to be the principles later.展开更多
The behaviors of time-dependent interaction between two buoyancy-driven in-line deformable drops rising in pure glycerin at Re b 1 were studied,where the diameter for the leading drops ranged from 9.51 mm to12.6 mm an...The behaviors of time-dependent interaction between two buoyancy-driven in-line deformable drops rising in pure glycerin at Re b 1 were studied,where the diameter for the leading drops ranged from 9.51 mm to12.6 mm and for trailing drops from 12.7 mm to 15.8 mm.The situation while a larger drop chasing a smaller one was specifically considered which typically led to the smaller drop "coating" the larger one.Two approaches,the geometric feature approach and the energy change one,were used to judge the starting and ending times of the interaction between two drops.Based on a conical wake model,the drag coefficient of two approaching drops was calculated.Due to the approaching effect of the trailing drop,the leading drop was accelerated and the average drag coefficient was smaller than that for a free rising single drop.The frequency spectrums of the lateral oscillation of two drops during the interaction were obtained by using Fourier analysis.The oscillation frequency of the interactional drops was also different from that for a free rising single drop because of the wake effect produced by the leading drop.Due to a superposition of the drop shape oscillation and the drop internal circulation,the transverse oscillation frequencies of two drops have the same trend during the approaching process.展开更多
目的:探讨原发性肝癌患者预后的危险因素,为该病患者的临床诊疗和预后判断提供科学依据。方法:以2018年监测、流行病学和结果(Surveillance,Epidemiology,and End Results,SEER)数据库原发性肝癌患者作为研究对象,收集人口学资料、临床...目的:探讨原发性肝癌患者预后的危险因素,为该病患者的临床诊疗和预后判断提供科学依据。方法:以2018年监测、流行病学和结果(Surveillance,Epidemiology,and End Results,SEER)数据库原发性肝癌患者作为研究对象,收集人口学资料、临床指标和预后随访信息,运用单因素和多因素logistic回归分析影响患者术后生存的危险因素。采用一致性指数评价模型的预测能力,构建受试者工作特征曲线分析预测模型的效能。采用绘制森林图的方法对不同分期下肝癌患者的治疗方式进行分析。结果:该研究共收集2018年原发性肝癌患者1750例。单因素logistic回归结果表明,肿瘤分期、淋巴结转移、远处转移、婚姻状况、放化疗及手术是影响原发性肝癌患者生存的危险因素(P<0.05);多因素logistic回归分析结果表明,肿瘤分期[T2/T3相对于T1,OR=5.142/3.390,95%CI=(3.654~7.236)(/2.327~4.939),P<0.001]、远处转移(OR=4.810,95%CI=3.384~6.839,P<0.001)、婚姻状况(OR=0.729,95%CI=0.575~0.925,P=0.009)、放疗(OR=0.361,95%CI=0.260~0.503,P<0.001)、化疗(OR=0.512,95%CI=0.381~0.687,P=0.001)以及手术(OR=0.245,95%CI=0.105~0.574,P=0.028)是影响肝癌患者生存的危险因素。将logistic回归中有意义的变量如肿瘤分期、远处转移、婚姻状况、放化疗和手术情况进行预测模型的构建,研究显示该模型一致性指数为0.786(95%CI=0.762~0.810),曲线下面积(area under the curve,AUC)为0.790(95%CI=0.764~0.812)。仅放疗这种干预方式在任何肿瘤分期的患者中都展现出了优势(P=0.003、P=0.013、P=0.003)。在未发生淋巴结转移的患者中无论哪种干预方式都会降低肝癌患者的病死率(P<0.001,P=0.001,P<0.001,P=0.004),但是在发生淋巴结转移的患者中,是否进行干预对肝癌患者的生存没有影响(P>0.05)。在未发生远处转移的患者中,仅进行放疗、化疗或化疗+放疗干预方式的患者与未进行干预的患者相比生存率更高(P<0.001,P=0.001,P<0.001,P=0.004),在发生远处转移的患者中,仅进行放疗的干预方式展现出优势(P=0.002)。结论:肿瘤分期、远处转移、婚姻状况、放化疗和手术情况是影响原发性肝癌预后的危险因素。展开更多
目的探讨不明原因发热(fever of unknown origin,FUO)住院患者生活质量状况及其影响因素。方法采用便利取样法,对本科室212例不明原因发热患者进行调查,了解其生活质量状况及影响因素。结果 FUO患者生活质量总分及躯体功能、躯体职能、...目的探讨不明原因发热(fever of unknown origin,FUO)住院患者生活质量状况及其影响因素。方法采用便利取样法,对本科室212例不明原因发热患者进行调查,了解其生活质量状况及影响因素。结果 FUO患者生活质量总分及躯体功能、躯体职能、身体疼痛、总体健康、活力、社会功能、心理健康维度得分均明显低于国内常模,组间比较,均P<0.001,差异有统计学意义;多重回归分析显示年龄、发热持续时间、家庭人均月收入及婚姻状况是FUO患者的影响因素。结论 FUO患者生活质量较低,其中年龄大、病程较长、家庭人均月收入较低、无配偶是FUO患者生活质量的危险因素。展开更多
基金financially supported by the Natural Science Foundation of Jiangxi,China(grant No.:20142BAB216015)Jiangxi Key Laboratory for Advanced Copper and Tungsten Materials,China(grant No.:2013-KLP-07)
文摘The AZ91 D magnesium alloy containing rare earth Gd was prepared in this study, and the effect of semi-solid isothermal heat treatment on the microstructure of the alloy was investigated to obtain an optimum semi-solid structure. Results show that Gd can refine the microstructure of AZ91 D magnesium alloy, and the optimum semi-solid AZ91 D microstructure can be achieved by adding 1.5wt.% Gd. After treated at 585 °C for 30 min, the well distributed rose-shaped and near-spherical semi-solid microstructures of AZ91D+1.5wt.%Gd alloy can be obtained. The liquid phase of the semi-solid alloy consists of three components, namely, the molten pool, the "entrapped liquid" pool and the liner liquid film which separates two neighbor particles. The solid phase is composed of two phases, the primary α-Mg particles and the α-Mg phase formed in the second stage of solidification. With the increase of holding time, melting which causes the decrease of the primary α-Mg particle size is the dominant mechanism in the initial stage while coalescence and Ostwald ripening tend to be the principles later.
基金Supported by the National Natural Science Foundation of China(21376016,21506005)
文摘The behaviors of time-dependent interaction between two buoyancy-driven in-line deformable drops rising in pure glycerin at Re b 1 were studied,where the diameter for the leading drops ranged from 9.51 mm to12.6 mm and for trailing drops from 12.7 mm to 15.8 mm.The situation while a larger drop chasing a smaller one was specifically considered which typically led to the smaller drop "coating" the larger one.Two approaches,the geometric feature approach and the energy change one,were used to judge the starting and ending times of the interaction between two drops.Based on a conical wake model,the drag coefficient of two approaching drops was calculated.Due to the approaching effect of the trailing drop,the leading drop was accelerated and the average drag coefficient was smaller than that for a free rising single drop.The frequency spectrums of the lateral oscillation of two drops during the interaction were obtained by using Fourier analysis.The oscillation frequency of the interactional drops was also different from that for a free rising single drop because of the wake effect produced by the leading drop.Due to a superposition of the drop shape oscillation and the drop internal circulation,the transverse oscillation frequencies of two drops have the same trend during the approaching process.
文摘目的:探讨原发性肝癌患者预后的危险因素,为该病患者的临床诊疗和预后判断提供科学依据。方法:以2018年监测、流行病学和结果(Surveillance,Epidemiology,and End Results,SEER)数据库原发性肝癌患者作为研究对象,收集人口学资料、临床指标和预后随访信息,运用单因素和多因素logistic回归分析影响患者术后生存的危险因素。采用一致性指数评价模型的预测能力,构建受试者工作特征曲线分析预测模型的效能。采用绘制森林图的方法对不同分期下肝癌患者的治疗方式进行分析。结果:该研究共收集2018年原发性肝癌患者1750例。单因素logistic回归结果表明,肿瘤分期、淋巴结转移、远处转移、婚姻状况、放化疗及手术是影响原发性肝癌患者生存的危险因素(P<0.05);多因素logistic回归分析结果表明,肿瘤分期[T2/T3相对于T1,OR=5.142/3.390,95%CI=(3.654~7.236)(/2.327~4.939),P<0.001]、远处转移(OR=4.810,95%CI=3.384~6.839,P<0.001)、婚姻状况(OR=0.729,95%CI=0.575~0.925,P=0.009)、放疗(OR=0.361,95%CI=0.260~0.503,P<0.001)、化疗(OR=0.512,95%CI=0.381~0.687,P=0.001)以及手术(OR=0.245,95%CI=0.105~0.574,P=0.028)是影响肝癌患者生存的危险因素。将logistic回归中有意义的变量如肿瘤分期、远处转移、婚姻状况、放化疗和手术情况进行预测模型的构建,研究显示该模型一致性指数为0.786(95%CI=0.762~0.810),曲线下面积(area under the curve,AUC)为0.790(95%CI=0.764~0.812)。仅放疗这种干预方式在任何肿瘤分期的患者中都展现出了优势(P=0.003、P=0.013、P=0.003)。在未发生淋巴结转移的患者中无论哪种干预方式都会降低肝癌患者的病死率(P<0.001,P=0.001,P<0.001,P=0.004),但是在发生淋巴结转移的患者中,是否进行干预对肝癌患者的生存没有影响(P>0.05)。在未发生远处转移的患者中,仅进行放疗、化疗或化疗+放疗干预方式的患者与未进行干预的患者相比生存率更高(P<0.001,P=0.001,P<0.001,P=0.004),在发生远处转移的患者中,仅进行放疗的干预方式展现出优势(P=0.002)。结论:肿瘤分期、远处转移、婚姻状况、放化疗和手术情况是影响原发性肝癌预后的危险因素。
