目的:分析瑞金甲状腺影像报告与数据系统(Ruijin-thyroid imaging reporting and data system,RJTIRADS)联合细针穿刺活检(fine-needle aspiration biopsy,FNAB)在老年甲状腺结节患者中的诊断价值。方法:2017年4月至2020年4月,选取在安...目的:分析瑞金甲状腺影像报告与数据系统(Ruijin-thyroid imaging reporting and data system,RJTIRADS)联合细针穿刺活检(fine-needle aspiration biopsy,FNAB)在老年甲状腺结节患者中的诊断价值。方法:2017年4月至2020年4月,选取在安徽省宿州市立医院超声科和上海交通大学医学院附属瑞金医院超声科检查并行FNAB及手术治疗的甲状腺结节病例,共纳入117例≥60岁的患者,其中男性30例,女性87例,共129个结节,98个为恶性结节,31个为良性结节。对患者所有结节的超声图像进行分析,观察并记录结节的大小、内部结构、回声、形态、边缘、钙化灶。采用RJ-TIRADS分类方法(计数版),0个恶性特征评为3类,1个恶性特征评为4A类,2个恶性特征评为4B类,3~4个恶性特征评为4C类,5个恶性特征评为5类。以术后组织病理诊断为金标准,计算老年患者中RJ-TITADS及FNAB单独或联合诊断甲状腺癌的灵敏度、特异度、阳性预测值、阴性预测值和准确率。结果:实性的超声特征在男性和女性甲状腺癌患者中分别占91.7%和100%,差异有统计学意义(P<0.05);RJ-TIRADS分类结果显示,老年患者中4A^4C类结节的恶性风险(59.3%、88.4%、100%)高于整体人群中4A^4C类结节的恶性风险(5.0%~20.0%、21.0%~50.0%、51.0%~90.0%)(P<0.05);FNAB诊断甲状腺癌的灵敏度、特异度、准确率分别为99.0%、83.9%和95.3%,高于实性、低回声、纵横比>1、边缘不光整、微钙化这5个可疑恶性超声特征的诊断价值;FNAB联合RJ-TIRADS可将≥RJ-TIRADS 4A结节的诊断特异度、准确率从29.0%、82.9%提高到87.1%、96.9%。结论:老年甲状腺癌患者中,女性患者出现实性结节多于男性;老年患者中RJ-TIRADS(计数版)4类结节的恶性风险较整体人群升高;FNAB联合RJ-TIRADS可提高甲状腺结节的超声诊断效能。展开更多
当前大多数Linux发行版使用功能强大的glibc(GNU C library)作为C标准库(简称C库),但glibc的LGPL协议存在商用不友好条款,制约了商业Linux发行版的推广.一种可行的解决方案是选择某个与glibc相比尚有功能缺陷但适宜商用的C库加以补全,...当前大多数Linux发行版使用功能强大的glibc(GNU C library)作为C标准库(简称C库),但glibc的LGPL协议存在商用不友好条款,制约了商业Linux发行版的推广.一种可行的解决方案是选择某个与glibc相比尚有功能缺陷但适宜商用的C库加以补全,从而制成新的C库以替代glibc.开源欧拉(openEuler)操作系统社区以MIT协议的musl libc作为新的C库选型.新C库对已有应用软件的兼容是成功替换的关键,而精确的兼容性分析算法不仅可以定位缺失API,还可以量化计算兼容性和API补全的优先级.为此,提出兼容性分析算法来研究openEuler的4种主要软件生态中的musl libc兼容性和缺失API优先级.基于应用软件包之间的依赖关系和谷歌PageRank算法的思想,提出了PackageRank算法和APIRank算法,分别用于软件包兼容性度量和优先级计算.这2种算法提供了系统个性化兼容分析的方法,所需信息易于获取,适用于缺乏用户数据统计的、尚不完整而仍有开发需求的系统及构件.这2种算法在musl libc上的分析结果清晰准确,与软件生态的特点和现状相符,与musl libc的国际社区开发者的观点接近,为openEuler的新C库补全工作提供了有效指导.展开更多
The diffusion and chemical reactions inside the catalyst particles and the heterogeneous flow structure in the computational cells are key factors to affect the accuracy of the coarse-grid simulation in circulating fl...The diffusion and chemical reactions inside the catalyst particles and the heterogeneous flow structure in the computational cells are key factors to affect the accuracy of the coarse-grid simulation in circulating fluidized bed(CFB)methanation reactors.In this work,a particle-scale model is developed to calculate the effective reaction rate considering the transient diffusion and chemical reactions in the particle scale,i.e.,the scale of the single catalyst particle.A modified sub-grid drag model is proposed to consider the effects of the meso-scale and chemical reactions on the heterogeneous gas-solid interaction,where the meso-scale is between the single particle and the whole reactor and featured with the particle cluster.Subsequently,a coupled model is developed by integrating the particle-scale and modified sub-grid drag models into CFD.Moreover,the coupled model is validated to achieve accurate predictions on the CO methanation process in a CFB riser.Notably,the coupled model can be performed with a coarse grid(∼58 times particle diameter)and a large time step(0.005 s)to accelerate the simulation.By simply changing the reaction kinetics,different gas-solid catalytic reaction systems can be simulated by using the coupled model.展开更多
A facile and controllable one-step method to treat liquid hydrocarbons and synthesize vertical graphene nanowalls has been developed by using the technique of inductively-coupled plasma-enhanced chemical vapor deposit...A facile and controllable one-step method to treat liquid hydrocarbons and synthesize vertical graphene nanowalls has been developed by using the technique of inductively-coupled plasma-enhanced chemical vapor deposition for plasma cracking of n-dodecane.Herein,the morphology and microstructure of solid carbon material and graphene nanowalls are characterized in terms of different operating conditions,i.e.input power,H2/Ar ratio,injection rate and reaction temperature.The results reveal that the optimal operating conditions were 500 W,5:10,30μl min^-1 and 800℃ for the input power,H2/Ar ratio,injection rate and reaction temperature,respectively.In addition,the degree of graphitization and the gaseous product are analyzed by Raman spectroscopy and gas chromatography detection.It can be calculated from the Raman spectrum that the relative intensity of ID/IG is approximately 1.55,and I2D/IG is approximately 0.48,indicating that the graphene prepared from n-dodecane has a rich defect structure and a high degree of graphitization.By calculating the mass loading and detecting the outlet gas,we find that the cracking rate of n-dodecane is only 6%-7%and that the gaseous products below C2 mainly include CH4,C2H2,C2H4,C2H6 and H2.Among them,the proportion of hydrogen in the outlet gas of n-dodecane cracking ranges from 1.3%-15.1%under different hydrogen flows.Based on our research,we propose a brand new perspective for both liquid hydrocarbon treatment and other value-added product syntheses.展开更多
The use of atmospheric rotating gliding arc(RGA)plasma is proposed as a facile,scalable and catalyst-free approach to synthesizing hydrogen(H2)and graphene sheets from coalbed methane(CBM).CH4 is used as a CBM surroga...The use of atmospheric rotating gliding arc(RGA)plasma is proposed as a facile,scalable and catalyst-free approach to synthesizing hydrogen(H2)and graphene sheets from coalbed methane(CBM).CH4 is used as a CBM surrogate.Based on a previous investigation of discharge properties,product distribution and energy efficiency,the operating parameters such as CH4 concentration,applied voltage and gas flow rate can effectively affect the CH4 conversion rate,the selectivity of H2 and the properties of solid generated carbon.Nevertheless,the basic properties of RGA plasma and its role in CH4 conversion are scarcely mentioned.In the present work,a 3D RGA model,with a detailed nonequilibrium CH4/Ar plasma chemistry,is developed to validate the previous experiments on CBM conversion,aiming in particular at the distribution of H2 and other gas products.Our results demonstrate that the dynamics of RGA is derived from the joint effects of electron convection,electron migration and electron diffusion,and is prominently determined by the variation of the gas flow rate and applied voltage.Subsequently,a combined experimental and chemical kinetical simulation is performed to analyze the selectivity of gas products in an RGA reaction,taking into consideration the formation and loss pathways of crucial targeted substances(such as CH4,C2H2,H2 and H radicals)and corresponding contribution rates.Additionally,the effects of operating conditions on the properties of solid products are investigated by scanning electron microscopy(SEM)and Raman spectroscopy.The results show that increasing the applied voltage and decreasing CH4 concentration will change the solid carbon from its initial spherical structure into folded multilayer graphene sheets,while the size of the graphene sheets is slightly affected by the change in gas flow rate.展开更多
文摘目的:分析瑞金甲状腺影像报告与数据系统(Ruijin-thyroid imaging reporting and data system,RJTIRADS)联合细针穿刺活检(fine-needle aspiration biopsy,FNAB)在老年甲状腺结节患者中的诊断价值。方法:2017年4月至2020年4月,选取在安徽省宿州市立医院超声科和上海交通大学医学院附属瑞金医院超声科检查并行FNAB及手术治疗的甲状腺结节病例,共纳入117例≥60岁的患者,其中男性30例,女性87例,共129个结节,98个为恶性结节,31个为良性结节。对患者所有结节的超声图像进行分析,观察并记录结节的大小、内部结构、回声、形态、边缘、钙化灶。采用RJ-TIRADS分类方法(计数版),0个恶性特征评为3类,1个恶性特征评为4A类,2个恶性特征评为4B类,3~4个恶性特征评为4C类,5个恶性特征评为5类。以术后组织病理诊断为金标准,计算老年患者中RJ-TITADS及FNAB单独或联合诊断甲状腺癌的灵敏度、特异度、阳性预测值、阴性预测值和准确率。结果:实性的超声特征在男性和女性甲状腺癌患者中分别占91.7%和100%,差异有统计学意义(P<0.05);RJ-TIRADS分类结果显示,老年患者中4A^4C类结节的恶性风险(59.3%、88.4%、100%)高于整体人群中4A^4C类结节的恶性风险(5.0%~20.0%、21.0%~50.0%、51.0%~90.0%)(P<0.05);FNAB诊断甲状腺癌的灵敏度、特异度、准确率分别为99.0%、83.9%和95.3%,高于实性、低回声、纵横比>1、边缘不光整、微钙化这5个可疑恶性超声特征的诊断价值;FNAB联合RJ-TIRADS可将≥RJ-TIRADS 4A结节的诊断特异度、准确率从29.0%、82.9%提高到87.1%、96.9%。结论:老年甲状腺癌患者中,女性患者出现实性结节多于男性;老年患者中RJ-TIRADS(计数版)4类结节的恶性风险较整体人群升高;FNAB联合RJ-TIRADS可提高甲状腺结节的超声诊断效能。
基金This work was supported by the National Natural Science Foundation of China(grant numbers 22108167,U1862116,and 22038011)the Fundamental Research Funds for the Central Universities(grant number GK202103036).
文摘The diffusion and chemical reactions inside the catalyst particles and the heterogeneous flow structure in the computational cells are key factors to affect the accuracy of the coarse-grid simulation in circulating fluidized bed(CFB)methanation reactors.In this work,a particle-scale model is developed to calculate the effective reaction rate considering the transient diffusion and chemical reactions in the particle scale,i.e.,the scale of the single catalyst particle.A modified sub-grid drag model is proposed to consider the effects of the meso-scale and chemical reactions on the heterogeneous gas-solid interaction,where the meso-scale is between the single particle and the whole reactor and featured with the particle cluster.Subsequently,a coupled model is developed by integrating the particle-scale and modified sub-grid drag models into CFD.Moreover,the coupled model is validated to achieve accurate predictions on the CO methanation process in a CFB riser.Notably,the coupled model can be performed with a coarse grid(∼58 times particle diameter)and a large time step(0.005 s)to accelerate the simulation.By simply changing the reaction kinetics,different gas-solid catalytic reaction systems can be simulated by using the coupled model.
文摘A facile and controllable one-step method to treat liquid hydrocarbons and synthesize vertical graphene nanowalls has been developed by using the technique of inductively-coupled plasma-enhanced chemical vapor deposition for plasma cracking of n-dodecane.Herein,the morphology and microstructure of solid carbon material and graphene nanowalls are characterized in terms of different operating conditions,i.e.input power,H2/Ar ratio,injection rate and reaction temperature.The results reveal that the optimal operating conditions were 500 W,5:10,30μl min^-1 and 800℃ for the input power,H2/Ar ratio,injection rate and reaction temperature,respectively.In addition,the degree of graphitization and the gaseous product are analyzed by Raman spectroscopy and gas chromatography detection.It can be calculated from the Raman spectrum that the relative intensity of ID/IG is approximately 1.55,and I2D/IG is approximately 0.48,indicating that the graphene prepared from n-dodecane has a rich defect structure and a high degree of graphitization.By calculating the mass loading and detecting the outlet gas,we find that the cracking rate of n-dodecane is only 6%-7%and that the gaseous products below C2 mainly include CH4,C2H2,C2H4,C2H6 and H2.Among them,the proportion of hydrogen in the outlet gas of n-dodecane cracking ranges from 1.3%-15.1%under different hydrogen flows.Based on our research,we propose a brand new perspective for both liquid hydrocarbon treatment and other value-added product syntheses.
基金supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China (No. 51621005)China Postdoctoral Science Foundation (No. 2018M630672)
文摘The use of atmospheric rotating gliding arc(RGA)plasma is proposed as a facile,scalable and catalyst-free approach to synthesizing hydrogen(H2)and graphene sheets from coalbed methane(CBM).CH4 is used as a CBM surrogate.Based on a previous investigation of discharge properties,product distribution and energy efficiency,the operating parameters such as CH4 concentration,applied voltage and gas flow rate can effectively affect the CH4 conversion rate,the selectivity of H2 and the properties of solid generated carbon.Nevertheless,the basic properties of RGA plasma and its role in CH4 conversion are scarcely mentioned.In the present work,a 3D RGA model,with a detailed nonequilibrium CH4/Ar plasma chemistry,is developed to validate the previous experiments on CBM conversion,aiming in particular at the distribution of H2 and other gas products.Our results demonstrate that the dynamics of RGA is derived from the joint effects of electron convection,electron migration and electron diffusion,and is prominently determined by the variation of the gas flow rate and applied voltage.Subsequently,a combined experimental and chemical kinetical simulation is performed to analyze the selectivity of gas products in an RGA reaction,taking into consideration the formation and loss pathways of crucial targeted substances(such as CH4,C2H2,H2 and H radicals)and corresponding contribution rates.Additionally,the effects of operating conditions on the properties of solid products are investigated by scanning electron microscopy(SEM)and Raman spectroscopy.The results show that increasing the applied voltage and decreasing CH4 concentration will change the solid carbon from its initial spherical structure into folded multilayer graphene sheets,while the size of the graphene sheets is slightly affected by the change in gas flow rate.
