Linearization of Radiative Transfer Equation (RTE) is the key step in physical retrieval of atmospheric temperature and moisture profiles from InfRared (IR) sounder observations. In this paper, the successive forms of...Linearization of Radiative Transfer Equation (RTE) is the key step in physical retrieval of atmospheric temperature and moisture profiles from InfRared (IR) sounder observations. In this paper, the successive forms of temperature and water vapor mixing ratio component weighting functions are derived by applying one term variation method to RTE with surface emissivity and solar reflectivity contained. Retrivals of temperature and water vapor mixing ratio profiles from simulated Atmospheric Infrared Sounder (AIRS) observations with surface emissivity and solar reflectivity are presented.展开更多
Surface temperature changes of building materials affect the calculation of heat flow and thus the energy use in heating and cooling. The surface heat transfer coefficient , limiting the heat flow between material sur...Surface temperature changes of building materials affect the calculation of heat flow and thus the energy use in heating and cooling. The surface heat transfer coefficient , limiting the heat flow between material surface and ambient air is normally taken as a constant. In this study we propose a time-dependent function . We estimate from unidirectional heat flow experiments with transient and steady-state conditions. Using temperature measurements and the conservation of energy at the surface including convective and irradiative boundary conditions, the value of was obtained both using Finite Difference and Taylor Polynomials methods. Numerical solutions of temperature distribution as function of time were improved with the obtained -functions compared to with constant . There were no clear difference between on different materials, and the final values observed were in the order of magnitude expected from the literature.展开更多
承接产业转移对促进区域协调发展具有重要意义。基于2013—2021年湘南湘西示范区数据,通过构建承接产业转移能力评价指标体系,使用熵权逼近理想解排序法(technique for order preference by similarity to an ideal solution,TOPSIS法)...承接产业转移对促进区域协调发展具有重要意义。基于2013—2021年湘南湘西示范区数据,通过构建承接产业转移能力评价指标体系,使用熵权逼近理想解排序法(technique for order preference by similarity to an ideal solution,TOPSIS法)测度承接能力;再利用障碍度模型识别影响承接能力的关键因素。研究结果表明,2013—2021年,示范区内六个地区承接产业转移能力均呈现逐年提升态势,但存在明显差距;邮电业务量、实际利用外资、普通高等学校在校学生数等是阻碍承接能力提升的关键因素。最后根据研究结论提出相应的建议。展开更多
目的探讨酰胺质子转移加权成像(amide proton transfer weighted imaging,APTw)的影像组学术前预测宫颈癌淋巴血管间隙侵犯(lymphovascular space invasion,LVSI)的价值。材料与方法回顾性分析经手术病理证实的宫颈癌患者病例及影像资...目的探讨酰胺质子转移加权成像(amide proton transfer weighted imaging,APTw)的影像组学术前预测宫颈癌淋巴血管间隙侵犯(lymphovascular space invasion,LVSI)的价值。材料与方法回顾性分析经手术病理证实的宫颈癌患者病例及影像资料66例。所有患者均行盆腔3.0 T MRI检查,包括轴位T2WI、矢状位T2WI、动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)和3D-APTw序列扫描。在APTw-T2WI融合图像上对肿瘤实质区域进行感兴趣区(region of interest,ROI)勾画并记录APT值。在APT重建图像上进行肿瘤病灶分割并提取影像组学特征。采用组内相关系数(intra-class correlation coefficient,ICC)选取观察者内和观察者间复测信度好的影像组学特征(ICC>0.900)。采用递归特征消除法(recursive feature elimination,RFE)及最小绝对收缩和选择算子(least absolute shrinkage and selection operator,LASSO)算法进行特征降维和筛选。基于logistic回归分类器构建临床模型、APTw影像组学模型和联合组学模型。采用受试者工作特征(receiver operating characteristic,ROC)曲线和决策曲线分析(decision curve analysis,DCA)评估模型的诊断效能和临床价值,采用DeLong检验比较不同模型的预测效能。结果在训练集中,APTw影像组学模型预测宫颈癌LVSI的效能高于临床模型(AUC=0.826 vs.0.675),差异有统计学意义(DeLong检验P<0.05)。联合组学模型在训练集和测试集中的AUC值分别为0.838和0.825。DeLong检验结果显示,联合组学模型在训练集中术前评估LVSI的效能显著高于临床模型和APTw影像组学模型(P均<0.05)。决策曲线显示APTw影像组学模型和联合组学模型在训练集和测试集中均具有较高的临床价值。结论基于APTw的影像组学模型在术前预测宫颈癌LVSI方面具有较高的潜力,联合临床因素能进一步提高预测效能,有望为宫颈癌患者的个体化治疗和预后评估提供重要的支持。展开更多
目的对比磁共振酰胺质子转移(Amide Proton Transfer,APT)成像、扩散加权成像(Diffusion Weighted Imaging,DWI)和动态增强(Dynamic Contrast-Enhanced,DCE)成像以及3者联合应用在鉴别乳腺良恶性病变中的诊断价值。方法纳入55例乳腺疾...目的对比磁共振酰胺质子转移(Amide Proton Transfer,APT)成像、扩散加权成像(Diffusion Weighted Imaging,DWI)和动态增强(Dynamic Contrast-Enhanced,DCE)成像以及3者联合应用在鉴别乳腺良恶性病变中的诊断价值。方法纳入55例乳腺疾病患者,均进行APT、DWI以及DCE扫描,测量非对称磁化转移(Magnetization Transfer Asymmetry,MTRasym)率和表观扩散系数(Apparent Diffusion Coefficient,ADC)值,并记录乳腺影像报告和数据系统的分类。分析乳腺良恶性病变各参数之间的差异,使用Logistic回归建立联合诊断模型,采用受试者工作特征曲线(Receive Operating Characteristic,ROC)计算各诊断模型在乳腺良恶性病变中的诊断价值,并比较恶性病变中不同病理因素组间的差异以及各病理因素与APT之间的相关性。结果恶性组中MTRasym和ADC值均小于良性组,差异具有统计学意义(均P<0.05),DWI、APT、DCE以及APT+DCE、APT+DWI、DCE+DWI、DWI+APT+DCE联合模型鉴别乳腺良恶性病变的曲线下面积(Area Under Curve,AUC)分别为0.804、0.723、0.741以及0.782、0.895、0.897、0.970;DWI+APT+DCE联合诊断模型的AUC显著大于DWI、APT、DCE以及任意两者联合诊断模型(均P<0.05)。Ki-67高表达组的MTRasym值较低表达组高[(3.934%±0.883%)v s.(3.192%±0.949%)],乳腺癌浸润程度组织学分级Ⅲ级组的M T R a s y m值较Ⅱ级组高[(4.225%±0.932%)vs.(3.451%±0.873%)],差异均有统计学意义(均P<0.05),并且APT与两者均呈中度正相关(r=0.627、0.537,均P<0.05)。结论APT成像技术在乳腺良恶性病变的鉴别中具有较好的诊断价值,与常规DWI、DCE成像无显著差异,并且三者联合应用的诊断价值更高。展开更多
文摘Linearization of Radiative Transfer Equation (RTE) is the key step in physical retrieval of atmospheric temperature and moisture profiles from InfRared (IR) sounder observations. In this paper, the successive forms of temperature and water vapor mixing ratio component weighting functions are derived by applying one term variation method to RTE with surface emissivity and solar reflectivity contained. Retrivals of temperature and water vapor mixing ratio profiles from simulated Atmospheric Infrared Sounder (AIRS) observations with surface emissivity and solar reflectivity are presented.
文摘Surface temperature changes of building materials affect the calculation of heat flow and thus the energy use in heating and cooling. The surface heat transfer coefficient , limiting the heat flow between material surface and ambient air is normally taken as a constant. In this study we propose a time-dependent function . We estimate from unidirectional heat flow experiments with transient and steady-state conditions. Using temperature measurements and the conservation of energy at the surface including convective and irradiative boundary conditions, the value of was obtained both using Finite Difference and Taylor Polynomials methods. Numerical solutions of temperature distribution as function of time were improved with the obtained -functions compared to with constant . There were no clear difference between on different materials, and the final values observed were in the order of magnitude expected from the literature.
文摘承接产业转移对促进区域协调发展具有重要意义。基于2013—2021年湘南湘西示范区数据,通过构建承接产业转移能力评价指标体系,使用熵权逼近理想解排序法(technique for order preference by similarity to an ideal solution,TOPSIS法)测度承接能力;再利用障碍度模型识别影响承接能力的关键因素。研究结果表明,2013—2021年,示范区内六个地区承接产业转移能力均呈现逐年提升态势,但存在明显差距;邮电业务量、实际利用外资、普通高等学校在校学生数等是阻碍承接能力提升的关键因素。最后根据研究结论提出相应的建议。
文摘目的探讨酰胺质子转移加权成像(amide proton transfer weighted imaging,APTw)的影像组学术前预测宫颈癌淋巴血管间隙侵犯(lymphovascular space invasion,LVSI)的价值。材料与方法回顾性分析经手术病理证实的宫颈癌患者病例及影像资料66例。所有患者均行盆腔3.0 T MRI检查,包括轴位T2WI、矢状位T2WI、动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)和3D-APTw序列扫描。在APTw-T2WI融合图像上对肿瘤实质区域进行感兴趣区(region of interest,ROI)勾画并记录APT值。在APT重建图像上进行肿瘤病灶分割并提取影像组学特征。采用组内相关系数(intra-class correlation coefficient,ICC)选取观察者内和观察者间复测信度好的影像组学特征(ICC>0.900)。采用递归特征消除法(recursive feature elimination,RFE)及最小绝对收缩和选择算子(least absolute shrinkage and selection operator,LASSO)算法进行特征降维和筛选。基于logistic回归分类器构建临床模型、APTw影像组学模型和联合组学模型。采用受试者工作特征(receiver operating characteristic,ROC)曲线和决策曲线分析(decision curve analysis,DCA)评估模型的诊断效能和临床价值,采用DeLong检验比较不同模型的预测效能。结果在训练集中,APTw影像组学模型预测宫颈癌LVSI的效能高于临床模型(AUC=0.826 vs.0.675),差异有统计学意义(DeLong检验P<0.05)。联合组学模型在训练集和测试集中的AUC值分别为0.838和0.825。DeLong检验结果显示,联合组学模型在训练集中术前评估LVSI的效能显著高于临床模型和APTw影像组学模型(P均<0.05)。决策曲线显示APTw影像组学模型和联合组学模型在训练集和测试集中均具有较高的临床价值。结论基于APTw的影像组学模型在术前预测宫颈癌LVSI方面具有较高的潜力,联合临床因素能进一步提高预测效能,有望为宫颈癌患者的个体化治疗和预后评估提供重要的支持。
文摘目的对比磁共振酰胺质子转移(Amide Proton Transfer,APT)成像、扩散加权成像(Diffusion Weighted Imaging,DWI)和动态增强(Dynamic Contrast-Enhanced,DCE)成像以及3者联合应用在鉴别乳腺良恶性病变中的诊断价值。方法纳入55例乳腺疾病患者,均进行APT、DWI以及DCE扫描,测量非对称磁化转移(Magnetization Transfer Asymmetry,MTRasym)率和表观扩散系数(Apparent Diffusion Coefficient,ADC)值,并记录乳腺影像报告和数据系统的分类。分析乳腺良恶性病变各参数之间的差异,使用Logistic回归建立联合诊断模型,采用受试者工作特征曲线(Receive Operating Characteristic,ROC)计算各诊断模型在乳腺良恶性病变中的诊断价值,并比较恶性病变中不同病理因素组间的差异以及各病理因素与APT之间的相关性。结果恶性组中MTRasym和ADC值均小于良性组,差异具有统计学意义(均P<0.05),DWI、APT、DCE以及APT+DCE、APT+DWI、DCE+DWI、DWI+APT+DCE联合模型鉴别乳腺良恶性病变的曲线下面积(Area Under Curve,AUC)分别为0.804、0.723、0.741以及0.782、0.895、0.897、0.970;DWI+APT+DCE联合诊断模型的AUC显著大于DWI、APT、DCE以及任意两者联合诊断模型(均P<0.05)。Ki-67高表达组的MTRasym值较低表达组高[(3.934%±0.883%)v s.(3.192%±0.949%)],乳腺癌浸润程度组织学分级Ⅲ级组的M T R a s y m值较Ⅱ级组高[(4.225%±0.932%)vs.(3.451%±0.873%)],差异均有统计学意义(均P<0.05),并且APT与两者均呈中度正相关(r=0.627、0.537,均P<0.05)。结论APT成像技术在乳腺良恶性病变的鉴别中具有较好的诊断价值,与常规DWI、DCE成像无显著差异,并且三者联合应用的诊断价值更高。
