目的探究血清分泌型卷曲相关蛋白5(secreted frizzled related protein 5,SFRP-5)、C-X-C基序趋化因子配体16(C-X-C motif chemokine ligand 16,CXCL16)对心肌梗死患者经皮冠状动脉介入(percutaneous coronary intervention,PCI)治疗后...目的探究血清分泌型卷曲相关蛋白5(secreted frizzled related protein 5,SFRP-5)、C-X-C基序趋化因子配体16(C-X-C motif chemokine ligand 16,CXCL16)对心肌梗死患者经皮冠状动脉介入(percutaneous coronary intervention,PCI)治疗后心力衰竭(heart failure,HF)发生的预测价值。方法选取2022年6月至2024年1月于保定市第二中心医院实施PCI治疗的心肌梗死患者152例为研究对象。术后随访1年,根据患者是否发生HF分为HF组和(n=47)非HF组(n=105)。采用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)法检测PCI治疗前患者血清SFRP-5、CXCL16的浓度;采用多因素Logistic回归法分析影响心肌梗死患者PCI治疗后HF发生的因素;绘制受试者工作特征(receiver operating characteristic,ROC)曲线分析血清SFRP-5、CXCL16浓度对心肌梗死患者PCI治疗后HF发生的预测价值。结果与非HF组患者比较,HF组患者性别、体质量指数(body mass index,BMI)、吸烟史、原发性高血压(高血压)史、糖尿病史、收缩压、舒张压及血肌酐(serum creatinine,Scr)、空腹血糖、总胆固醇浓度比较,差异无统计学意义(P>0.05);血清SFRP-5浓度显著降低,年龄及纤维蛋白原、CXCL16浓度浓度显著升高,差异有统计学意义(P<0.05)。年龄(OR=1.712)、纤维蛋白原(OR=2.240)、CXCL16浓度升高(OR=3.948),SFRP-5浓度降低(OR=0.284)均是影响心肌梗死患者PCI治疗后HF发生的危险因素(P<0.05)。血清SFRP-5、CXCL16浓度单独预测心肌梗死患者PCI治疗后HF发生的曲线下面积(area under the curve,AUC)分别为0.698(95%CI:0.619~0.770)、0.801(95%CI:0.729~0.861),二者联合预测的AUC为0.952(95%CI:0.905~0.980),灵敏度为91.49%,特异度为91.43%。联合预测价值显著高于单一指标预测(Z_(三者联合-SFRP-5)=5.839、Z_(三者联合-CXCL16)=3.564,P<0.05)。结论血清SFRP-5、CXCL16浓度对心肌梗死患者PCI治疗后HF发生具有一定的预测价值,且二者联合的预测价值更高。展开更多
This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both commo...This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.展开更多
Van der Waals(vdW)heterostructures have attracted much attention due to their distinctive optical,electrical,and thermal properties,demonstrating promising potential in areas such as photocatalysis,ultrafast photonics...Van der Waals(vdW)heterostructures have attracted much attention due to their distinctive optical,electrical,and thermal properties,demonstrating promising potential in areas such as photocatalysis,ultrafast photonics,and free electron radiation devices.Particularly,they are promising platforms for studying thermionic emission.It is illustrated that using vdW heterostructure-based thermionic emission can enhance heat transfer in vacuum devices.As a proof of concept,the approach is demonstrated to offer a promising solution for the long-standing overheating issue in X-ray tubes.Specifically,it is shown that the saturated target temperature of a 2000 W X-ray tube can be reduced from around 1200℃ to 490℃.Additionally,it is also demonstrated that by reducing the height of the Schottky barrier formed in the vdW heterostructures,the thermionic cooling performance can be enhanced.The findings pave the way for the development of high-power X-ray tubes.展开更多
So far quite a few ultraluminous X-ray(ULX) pulsars have been discovered.In this work,we construct a super-Eddington,magnetic accretion disk model to estimate the dipole magnetic field of eight ULX pulsars based on th...So far quite a few ultraluminous X-ray(ULX) pulsars have been discovered.In this work,we construct a super-Eddington,magnetic accretion disk model to estimate the dipole magnetic field of eight ULX pulsars based on their observed spin-up variations and luminosities.We obtain two branches of dipole magnetic field solutions.They are distributed in the range of B-(0.156-64.5) × 10^(10) G and-(0.275-79.0) × 10^(13) G corresponding to the low-and high-B solutions respectively.The low magnetic field solutions correspond to the state that the neutron stars are far away from the spin equilibrium,and the high magnetic field solutions are close to the spin equilibrium.The ultra-strong magnetic fields derived in Be-type ULX pulsars imply that the accretion mode in Be-type ULX pulsars could be more complicated than in the persistent ULX pulsars and may not be accounted for by the magnetized accretion disk model.We suggest that the transition between the accretor and the propeller regimes may be used to distinguish between the low-and high-B magnetic field solutions in addition to the detection of the cyclotron resonance scattering features.展开更多
针对X-Y平台中模型误差和扰动未知等问题,本文以夹胶玻璃自动切膜为应用背景,设计自动切膜恒力控制系统,并对系统中的交互力进行分析与建模。提出了一种改进线性自抗扰(linear active disturbance rejection controller,LADRC)力控制器...针对X-Y平台中模型误差和扰动未知等问题,本文以夹胶玻璃自动切膜为应用背景,设计自动切膜恒力控制系统,并对系统中的交互力进行分析与建模。提出了一种改进线性自抗扰(linear active disturbance rejection controller,LADRC)力控制器,将滑模控制嵌入到基于预报的线性跟踪微分器(tracking differentiator,TD)中,平衡滤波与相位滞后间的矛盾,利用分数阶比例微分(fractional order proportion differentiation,FOPD)快速响应跟踪力误差,并通过Lyapunov函数对改进线性跟踪微分器进行稳定性证明。通过与线性自抗扰进行比较,对所设计的控制器进行了仿真分析与实验验证。实验结果表明,当玻璃位置等参数发生变化时,基于改进跟踪微分器的线性自抗扰控制系统仍能较好地实现对切刀的交互力控制,有效保证切膜效果,证明了提出方法的有效性与实用性。展开更多
文摘目的探究血清分泌型卷曲相关蛋白5(secreted frizzled related protein 5,SFRP-5)、C-X-C基序趋化因子配体16(C-X-C motif chemokine ligand 16,CXCL16)对心肌梗死患者经皮冠状动脉介入(percutaneous coronary intervention,PCI)治疗后心力衰竭(heart failure,HF)发生的预测价值。方法选取2022年6月至2024年1月于保定市第二中心医院实施PCI治疗的心肌梗死患者152例为研究对象。术后随访1年,根据患者是否发生HF分为HF组和(n=47)非HF组(n=105)。采用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)法检测PCI治疗前患者血清SFRP-5、CXCL16的浓度;采用多因素Logistic回归法分析影响心肌梗死患者PCI治疗后HF发生的因素;绘制受试者工作特征(receiver operating characteristic,ROC)曲线分析血清SFRP-5、CXCL16浓度对心肌梗死患者PCI治疗后HF发生的预测价值。结果与非HF组患者比较,HF组患者性别、体质量指数(body mass index,BMI)、吸烟史、原发性高血压(高血压)史、糖尿病史、收缩压、舒张压及血肌酐(serum creatinine,Scr)、空腹血糖、总胆固醇浓度比较,差异无统计学意义(P>0.05);血清SFRP-5浓度显著降低,年龄及纤维蛋白原、CXCL16浓度浓度显著升高,差异有统计学意义(P<0.05)。年龄(OR=1.712)、纤维蛋白原(OR=2.240)、CXCL16浓度升高(OR=3.948),SFRP-5浓度降低(OR=0.284)均是影响心肌梗死患者PCI治疗后HF发生的危险因素(P<0.05)。血清SFRP-5、CXCL16浓度单独预测心肌梗死患者PCI治疗后HF发生的曲线下面积(area under the curve,AUC)分别为0.698(95%CI:0.619~0.770)、0.801(95%CI:0.729~0.861),二者联合预测的AUC为0.952(95%CI:0.905~0.980),灵敏度为91.49%,特异度为91.43%。联合预测价值显著高于单一指标预测(Z_(三者联合-SFRP-5)=5.839、Z_(三者联合-CXCL16)=3.564,P<0.05)。结论血清SFRP-5、CXCL16浓度对心肌梗死患者PCI治疗后HF发生具有一定的预测价值,且二者联合的预测价值更高。
基金Project(2023YFB4606200)supported by the National Key Research and Development Program of ChinaProject(2023-SSRF-HZ-503114-2)supported by Shanghai Synchrotron Radiation Facility,Instrument BL16U2,China。
文摘This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.
基金supported by National Natural Science Foundation of China(61921002 and 92163204)。
文摘Van der Waals(vdW)heterostructures have attracted much attention due to their distinctive optical,electrical,and thermal properties,demonstrating promising potential in areas such as photocatalysis,ultrafast photonics,and free electron radiation devices.Particularly,they are promising platforms for studying thermionic emission.It is illustrated that using vdW heterostructure-based thermionic emission can enhance heat transfer in vacuum devices.As a proof of concept,the approach is demonstrated to offer a promising solution for the long-standing overheating issue in X-ray tubes.Specifically,it is shown that the saturated target temperature of a 2000 W X-ray tube can be reduced from around 1200℃ to 490℃.Additionally,it is also demonstrated that by reducing the height of the Schottky barrier formed in the vdW heterostructures,the thermionic cooling performance can be enhanced.The findings pave the way for the development of high-power X-ray tubes.
基金supported by the National Key Research and Development Program of China (2016YFA0400803)the National Natural Science Foundation of China under grant Nos.11773015 and 10241301Project U1838201 supported by NSFC and CAS。
文摘So far quite a few ultraluminous X-ray(ULX) pulsars have been discovered.In this work,we construct a super-Eddington,magnetic accretion disk model to estimate the dipole magnetic field of eight ULX pulsars based on their observed spin-up variations and luminosities.We obtain two branches of dipole magnetic field solutions.They are distributed in the range of B-(0.156-64.5) × 10^(10) G and-(0.275-79.0) × 10^(13) G corresponding to the low-and high-B solutions respectively.The low magnetic field solutions correspond to the state that the neutron stars are far away from the spin equilibrium,and the high magnetic field solutions are close to the spin equilibrium.The ultra-strong magnetic fields derived in Be-type ULX pulsars imply that the accretion mode in Be-type ULX pulsars could be more complicated than in the persistent ULX pulsars and may not be accounted for by the magnetized accretion disk model.We suggest that the transition between the accretor and the propeller regimes may be used to distinguish between the low-and high-B magnetic field solutions in addition to the detection of the cyclotron resonance scattering features.
文摘针对X-Y平台中模型误差和扰动未知等问题,本文以夹胶玻璃自动切膜为应用背景,设计自动切膜恒力控制系统,并对系统中的交互力进行分析与建模。提出了一种改进线性自抗扰(linear active disturbance rejection controller,LADRC)力控制器,将滑模控制嵌入到基于预报的线性跟踪微分器(tracking differentiator,TD)中,平衡滤波与相位滞后间的矛盾,利用分数阶比例微分(fractional order proportion differentiation,FOPD)快速响应跟踪力误差,并通过Lyapunov函数对改进线性跟踪微分器进行稳定性证明。通过与线性自抗扰进行比较,对所设计的控制器进行了仿真分析与实验验证。实验结果表明,当玻璃位置等参数发生变化时,基于改进跟踪微分器的线性自抗扰控制系统仍能较好地实现对切刀的交互力控制,有效保证切膜效果,证明了提出方法的有效性与实用性。
