以钛网为基底,采用两步法(阳极氧化和电还原)成功制备了三维黑色TiO_(2)纳米管(3D Black TiO_(2)NTs)光电极。通过扫描电子显微镜(SEM)和X射线衍射(XRD)分别对3D Black TiO_(2)NTs光电极的表面形貌和结构进行了表征。结果表明,Black TiO...以钛网为基底,采用两步法(阳极氧化和电还原)成功制备了三维黑色TiO_(2)纳米管(3D Black TiO_(2)NTs)光电极。通过扫描电子显微镜(SEM)和X射线衍射(XRD)分别对3D Black TiO_(2)NTs光电极的表面形貌和结构进行了表征。结果表明,Black TiO_(2)NTs管径约为130 nm,管壁厚度为10 nm。通过线性伏安扫描(LSV)和电化学交流阻抗(EIS)对光电极的光电催化电化学活性进行了研究。研究发现在TiO_(2)NTs晶格引入Ti^(3+)之后,可以提高光生载流子的产生与分离速度,从而使得光电流密度显著提高。同时,Ti^(3+)自掺杂也有效增强了材料的电荷分离与传输性能,从而大大提高了电极的光电催化活性。将该光电极应用于光电催化降解亚甲基蓝(MB),降解120 min后MB完全降解,总有机碳(TOC)降解率高达86%。研究表明,3D Black TiO_(2)NTs光电极在有机废水处理中具有广阔的应用前景。展开更多
Differential pulse-position modulation(DP PM)can achieve a good compromise between power and bandwidth requirements.However,the output sequence has undetectable insertions and deletions.This paper proposes a successiv...Differential pulse-position modulation(DP PM)can achieve a good compromise between power and bandwidth requirements.However,the output sequence has undetectable insertions and deletions.This paper proposes a successive cancellation(SC)decoding scheme based on the weighted levenshtein distance(WLD)of polar codes for correcting insertions/deletions in DPPM systems.In this method,the WLD is used to calculate the transfer probabilities recursively to obtain likelihood ratios,and the low-complexity SC decoding method is built according to the error characteristics to match the DPPM system.Additionally,the proposed SC decoding scheme is extended to list decoding,which can further improve error correction performance.Simulation results show that the proposed scheme can effectively correct insertions/deletions in the DPPM system,which enhances its reliability and performance.展开更多
Carbenes as one of the most important class of intermediates have been widely utilized in various organic synthetic transformations.Carbene insertion-initiated ring-opening reactions of cyclic ethers offer a valuable ...Carbenes as one of the most important class of intermediates have been widely utilized in various organic synthetic transformations.Carbene insertion-initiated ring-opening reactions of cyclic ethers offer a valuable strategy for constructing new carbon-oxygen bonds.In comparison with traditional thermal or metal-mediated carbene transfer reactions,visible-light-promoted multi-component reaction strategy provides a mild and eco-friendly approach to access densely functionalized molecules.Recently,visible-light-induced multi-component carbene transfer reactions of diazo compounds have been rapidly developed and attracted a great deal of research interest of chemists owing to their advantages of simple operation,mild condition,high atom economy and rich structural diversity.This paper summarizes the recent research progress on the visible-light-promoted multi-component carbene transfer reactions of diazo compounds via ring-opening of cyclic ethers with various nucleophiles.The reaction patterns of different nucleophiles and their corresponding mechanism are described in this review.The future research direction and challenges in this area are also discussed.展开更多
目的探讨严重烧伤并发脓毒症患者血清NT-proBNP、HBDH水平与心功能不全的相关性及判别效能研究。方法回顾性纳入2023年3月至2025年3月收治的130例严重烧伤患者,分为脓毒症合并心功能不全组(n=22)、合并脓毒症组(n=33)及单纯烧伤组(n=75...目的探讨严重烧伤并发脓毒症患者血清NT-proBNP、HBDH水平与心功能不全的相关性及判别效能研究。方法回顾性纳入2023年3月至2025年3月收治的130例严重烧伤患者,分为脓毒症合并心功能不全组(n=22)、合并脓毒症组(n=33)及单纯烧伤组(n=75)。检测各组入院24 h、48 h、72 h血清PCT、hs-CRP、NT-proBNP、HBDH水平,记录LVEF、LAVI及SOFA评分,采用Pearson相关性分析及ROC曲线评估诊断效能。结果各时段HBDH、NT-proBNP水平均呈脓毒症合并心功能不全组>合并脓毒症组>单纯烧伤组,差异有统计学意义(P<0.05)。hs-CRP、PCT水平随时间延长而升高,脓毒症组及脓毒症合并心功能不全组>单纯烧伤组,差异有统计学意义(P<0.05),但脓毒症组与脓毒症合并心功能不全组间差异无统计学意义(P>0.05)。LVEF则单纯烧伤组>合并脓毒症组>脓毒症合并心功能不全组,差异有统计学意义(P<0.05);LAVI、SOFA评分单纯烧伤组<合并脓毒症组<脓毒症合并心功能不全组。相关性分析显示,入院24 h HBDH和48 h NT-proBNP与LVEF呈强负相关(|r|≥-0.7,P<0.05),与LAVI呈中等负相关(P<0.05)。ROC曲线分析显示,入院24 h HBDH联合48 h NT-proBNP诊断脓毒症合并心功能不全的AUC最大(0.852),优于单一指标(P<0.05)。结论动态监测严重烧伤患者血清NT-proBNP与HBDH水平有助于尽早发现脓毒症相关心功能不全,联合检测可提高诊断效能,为临床早期干预提供依据。展开更多
目的:本研究旨在探讨NT联合NIPT、早期唐氏筛查及四维超声检查在胎儿染色体疾病筛查中的临床应用价值,评估不同检测方法单独及联合使用时的检出率和诊断效能,为优化胎儿染色体异常的早期筛查策略提供依据。方法:回顾性分析2018年1月至2...目的:本研究旨在探讨NT联合NIPT、早期唐氏筛查及四维超声检查在胎儿染色体疾病筛查中的临床应用价值,评估不同检测方法单独及联合使用时的检出率和诊断效能,为优化胎儿染色体异常的早期筛查策略提供依据。方法:回顾性分析2018年1月至2024年10月于青海红十字医院行产前诊断的532例孕妇的临床数据,所有病例均行NT、NIPT、早期唐氏筛查、四维超声检查及羊水穿刺。分别计算各检测方法单独及联合筛查的阳性检出率、灵敏度、特异度、阳性预测值、阴性预测值及准确率,同时对多种检测联合方案的诊断效能进行ROC曲线分析。结果:两组孕妇的年龄、孕周、孕前BMI、居住地与文化程度均无统计学差异(P > 0.05)。单独检测中,相比NT、早期唐氏筛查及四维超声检查,NIPT具有较高的阳性检出率、灵敏度、特异度、阳性预测值、阴性预测值、准确率及AUC (P Objective: The aim of this study was to investigate the clinical application value of NT combined with NIPT, early Down’s screening, and four-dimensional ultrasonography in the screening of fetal chromosomal disorders, to assess the detection rate and diagnostic efficacy of different testing methods when used individually and in combination, and to provide a basis for optimising the early screening strategy for fetal chromosomal abnormalities. Methods: Clinical data of 532 pregnant women who underwent prenatal diagnosis in Qinghai Red Cross Hospital from January 2018 to October 2024 were retrospectively analysed, and all cases underwent NT, NIPT, early Down’s syndrome screening, four-dimensional ultrasonography, and amniocentesis. The positive detection rate, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each test alone and in combination were calculated, and the diagnostic efficacy of the combination of multiple tests was analysed by ROC curve. Results: There were no statistically significant differences in age, gestational week, pre-pregnancy BMI, place of residence, and education between the two groups (P > 0.05). Among individual tests, compared with NT, early Down’s screening, and 4D ultrasound, NIPT alone had a higher positive detection rate, sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and AUC (P < 0.05). Compared to individual screening, NT combined with early Down syndrome screening, and NT combined with four dimensional ultrasound examination, NT combined with NIPT had higher sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and AUC (P < 0.05). Conclusion: NT combined with NIPT, early Down’s syndrome screening, and four-dimensional ultrasound can significantly improve the detection rate and diagnostic accuracy of individual screening, especially the combined NT + NIPT program has high clinical value in the screening of fetal chromosomal abnormalities, which provides a scientific basis for optimizing the screening strategy for high-risk pregnant women.展开更多
Regulatory status of drug inserts in China is described in terms of its legalsystem, administrative ramifications and existing problems. Lack of government regulatoryenforcement, industry self-control mechanisms and a...Regulatory status of drug inserts in China is described in terms of its legalsystem, administrative ramifications and existing problems. Lack of government regulatoryenforcement, industry self-control mechanisms and academic research are blamed to be the root ofthese problems. The trend of regulatory policies on the issue is outlined and suggestions on severalimportant issues are made.展开更多
Thickness deposition is a crucial issue on the application of electroformed micro mold inserts. Edge concentration effect is the main source of the non-uniformity. The techniques of adopting a non-conducting shield, a...Thickness deposition is a crucial issue on the application of electroformed micro mold inserts. Edge concentration effect is the main source of the non-uniformity. The techniques of adopting a non-conducting shield, a secondary electrode and a movable cathode were explored to improve the thickness deposition uniformity during the nickel electroforming process. Regarding these techniques, a micro electroforming system with a movable cathode was particularly developed. The thickness variation of a 16 mm×16 mm electroformed sample decreased respectively from 150% to 35%, 12% and 18% by these three techniques. Combining these validated methods, anickelmold insert for microlens array was electroformed with satisfactory mechanical properties and high replication precision. It could be applied to the following injection molding process.展开更多
A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,an...A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,and the results show that the bending strength and fracture toughness of cemented carbide material decrease obviously under cyclic thermal load,while in the cooling process,the material mechanical property changes worse suddenly.The high-temperature mechanical property of SCS is the most stable,and that of YT15 is the worst.Further,a relation model among cutting temperature,cutting parameters and insert life is established.Finally,the measures to improve heavy cemented carbide inserts life are summarized from the aspects of cutting parameters selection,insert optimization design and TiCN,Al2O3,TiN complex insert coating.The research results are expected to provide support and reference for heavy cutting technology and insert technology.展开更多
The design of the flow field is highly responsible for the performance of the Proton Exchange Membrane Fuel Cell (PEMFC). In this study, pin type flow channel is numerically analyzed by arranging carbon made porous ma...The design of the flow field is highly responsible for the performance of the Proton Exchange Membrane Fuel Cell (PEMFC). In this study, pin type flow channel is numerically analyzed by arranging carbon made porous material in uniform and zigzag manner on the rib surface of the flow field. The study focuses on enhancing the performance of PEMFC by reducing liquid flooding in the interface between the rib and Gas Diffusion Layer (GDL). A single PEMFC having an active area of 25 cm2, with three flow channel designs (conventional serpentine, pin type flow channel with 2 mm cubical porous inserts in zigzag and uniform pattern) are modeled for the numerical analysis. The effect of porosity of the carbon inserts on the cell performance is studied by varying its value from 0.6 to 0.9. The results show that the performance of the flow channel with zigzag and uniformly positioned porous inserts is more than the conventional serpentine flow channel by 20.36% and 16.87% respectively. The reason for this increase is the removal of the accumulated water from the rib surface due to the capillary action of the porous carbon inserts. This helps in eliminating the stagnant water regions under the rib and thereby helps in reducing liquid flooding.展开更多
文摘以钛网为基底,采用两步法(阳极氧化和电还原)成功制备了三维黑色TiO_(2)纳米管(3D Black TiO_(2)NTs)光电极。通过扫描电子显微镜(SEM)和X射线衍射(XRD)分别对3D Black TiO_(2)NTs光电极的表面形貌和结构进行了表征。结果表明,Black TiO_(2)NTs管径约为130 nm,管壁厚度为10 nm。通过线性伏安扫描(LSV)和电化学交流阻抗(EIS)对光电极的光电催化电化学活性进行了研究。研究发现在TiO_(2)NTs晶格引入Ti^(3+)之后,可以提高光生载流子的产生与分离速度,从而使得光电流密度显著提高。同时,Ti^(3+)自掺杂也有效增强了材料的电荷分离与传输性能,从而大大提高了电极的光电催化活性。将该光电极应用于光电催化降解亚甲基蓝(MB),降解120 min后MB完全降解,总有机碳(TOC)降解率高达86%。研究表明,3D Black TiO_(2)NTs光电极在有机废水处理中具有广阔的应用前景。
基金supported by National Natural Science Foundation of China(No.61801327).
文摘Differential pulse-position modulation(DP PM)can achieve a good compromise between power and bandwidth requirements.However,the output sequence has undetectable insertions and deletions.This paper proposes a successive cancellation(SC)decoding scheme based on the weighted levenshtein distance(WLD)of polar codes for correcting insertions/deletions in DPPM systems.In this method,the WLD is used to calculate the transfer probabilities recursively to obtain likelihood ratios,and the low-complexity SC decoding method is built according to the error characteristics to match the DPPM system.Additionally,the proposed SC decoding scheme is extended to list decoding,which can further improve error correction performance.Simulation results show that the proposed scheme can effectively correct insertions/deletions in the DPPM system,which enhances its reliability and performance.
基金Science and Technology Foundation of Guizhou Province(No.QKHJC-ZK[2024]654)Guizhou Provincial University Key Laboratory of Advanced Functional Electronic Materials(No.QJ[2023]021).
文摘Carbenes as one of the most important class of intermediates have been widely utilized in various organic synthetic transformations.Carbene insertion-initiated ring-opening reactions of cyclic ethers offer a valuable strategy for constructing new carbon-oxygen bonds.In comparison with traditional thermal or metal-mediated carbene transfer reactions,visible-light-promoted multi-component reaction strategy provides a mild and eco-friendly approach to access densely functionalized molecules.Recently,visible-light-induced multi-component carbene transfer reactions of diazo compounds have been rapidly developed and attracted a great deal of research interest of chemists owing to their advantages of simple operation,mild condition,high atom economy and rich structural diversity.This paper summarizes the recent research progress on the visible-light-promoted multi-component carbene transfer reactions of diazo compounds via ring-opening of cyclic ethers with various nucleophiles.The reaction patterns of different nucleophiles and their corresponding mechanism are described in this review.The future research direction and challenges in this area are also discussed.
文摘目的探讨严重烧伤并发脓毒症患者血清NT-proBNP、HBDH水平与心功能不全的相关性及判别效能研究。方法回顾性纳入2023年3月至2025年3月收治的130例严重烧伤患者,分为脓毒症合并心功能不全组(n=22)、合并脓毒症组(n=33)及单纯烧伤组(n=75)。检测各组入院24 h、48 h、72 h血清PCT、hs-CRP、NT-proBNP、HBDH水平,记录LVEF、LAVI及SOFA评分,采用Pearson相关性分析及ROC曲线评估诊断效能。结果各时段HBDH、NT-proBNP水平均呈脓毒症合并心功能不全组>合并脓毒症组>单纯烧伤组,差异有统计学意义(P<0.05)。hs-CRP、PCT水平随时间延长而升高,脓毒症组及脓毒症合并心功能不全组>单纯烧伤组,差异有统计学意义(P<0.05),但脓毒症组与脓毒症合并心功能不全组间差异无统计学意义(P>0.05)。LVEF则单纯烧伤组>合并脓毒症组>脓毒症合并心功能不全组,差异有统计学意义(P<0.05);LAVI、SOFA评分单纯烧伤组<合并脓毒症组<脓毒症合并心功能不全组。相关性分析显示,入院24 h HBDH和48 h NT-proBNP与LVEF呈强负相关(|r|≥-0.7,P<0.05),与LAVI呈中等负相关(P<0.05)。ROC曲线分析显示,入院24 h HBDH联合48 h NT-proBNP诊断脓毒症合并心功能不全的AUC最大(0.852),优于单一指标(P<0.05)。结论动态监测严重烧伤患者血清NT-proBNP与HBDH水平有助于尽早发现脓毒症相关心功能不全,联合检测可提高诊断效能,为临床早期干预提供依据。
文摘目的:本研究旨在探讨NT联合NIPT、早期唐氏筛查及四维超声检查在胎儿染色体疾病筛查中的临床应用价值,评估不同检测方法单独及联合使用时的检出率和诊断效能,为优化胎儿染色体异常的早期筛查策略提供依据。方法:回顾性分析2018年1月至2024年10月于青海红十字医院行产前诊断的532例孕妇的临床数据,所有病例均行NT、NIPT、早期唐氏筛查、四维超声检查及羊水穿刺。分别计算各检测方法单独及联合筛查的阳性检出率、灵敏度、特异度、阳性预测值、阴性预测值及准确率,同时对多种检测联合方案的诊断效能进行ROC曲线分析。结果:两组孕妇的年龄、孕周、孕前BMI、居住地与文化程度均无统计学差异(P > 0.05)。单独检测中,相比NT、早期唐氏筛查及四维超声检查,NIPT具有较高的阳性检出率、灵敏度、特异度、阳性预测值、阴性预测值、准确率及AUC (P Objective: The aim of this study was to investigate the clinical application value of NT combined with NIPT, early Down’s screening, and four-dimensional ultrasonography in the screening of fetal chromosomal disorders, to assess the detection rate and diagnostic efficacy of different testing methods when used individually and in combination, and to provide a basis for optimising the early screening strategy for fetal chromosomal abnormalities. Methods: Clinical data of 532 pregnant women who underwent prenatal diagnosis in Qinghai Red Cross Hospital from January 2018 to October 2024 were retrospectively analysed, and all cases underwent NT, NIPT, early Down’s syndrome screening, four-dimensional ultrasonography, and amniocentesis. The positive detection rate, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each test alone and in combination were calculated, and the diagnostic efficacy of the combination of multiple tests was analysed by ROC curve. Results: There were no statistically significant differences in age, gestational week, pre-pregnancy BMI, place of residence, and education between the two groups (P > 0.05). Among individual tests, compared with NT, early Down’s screening, and 4D ultrasound, NIPT alone had a higher positive detection rate, sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and AUC (P < 0.05). Compared to individual screening, NT combined with early Down syndrome screening, and NT combined with four dimensional ultrasound examination, NT combined with NIPT had higher sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and AUC (P < 0.05). Conclusion: NT combined with NIPT, early Down’s syndrome screening, and four-dimensional ultrasound can significantly improve the detection rate and diagnostic accuracy of individual screening, especially the combined NT + NIPT program has high clinical value in the screening of fetal chromosomal abnormalities, which provides a scientific basis for optimizing the screening strategy for high-risk pregnant women.
文摘Regulatory status of drug inserts in China is described in terms of its legalsystem, administrative ramifications and existing problems. Lack of government regulatoryenforcement, industry self-control mechanisms and academic research are blamed to be the root ofthese problems. The trend of regulatory policies on the issue is outlined and suggestions on severalimportant issues are made.
基金Projects(51305465,91123012)supported by the National Natural Science Foundation of China
文摘Thickness deposition is a crucial issue on the application of electroformed micro mold inserts. Edge concentration effect is the main source of the non-uniformity. The techniques of adopting a non-conducting shield, a secondary electrode and a movable cathode were explored to improve the thickness deposition uniformity during the nickel electroforming process. Regarding these techniques, a micro electroforming system with a movable cathode was particularly developed. The thickness variation of a 16 mm×16 mm electroformed sample decreased respectively from 150% to 35%, 12% and 18% by these three techniques. Combining these validated methods, anickelmold insert for microlens array was electroformed with satisfactory mechanical properties and high replication precision. It could be applied to the following injection molding process.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51205095)Support Program for Key Youth(Grant No.1154G39)
文摘A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,and the results show that the bending strength and fracture toughness of cemented carbide material decrease obviously under cyclic thermal load,while in the cooling process,the material mechanical property changes worse suddenly.The high-temperature mechanical property of SCS is the most stable,and that of YT15 is the worst.Further,a relation model among cutting temperature,cutting parameters and insert life is established.Finally,the measures to improve heavy cemented carbide inserts life are summarized from the aspects of cutting parameters selection,insert optimization design and TiCN,Al2O3,TiN complex insert coating.The research results are expected to provide support and reference for heavy cutting technology and insert technology.
文摘The design of the flow field is highly responsible for the performance of the Proton Exchange Membrane Fuel Cell (PEMFC). In this study, pin type flow channel is numerically analyzed by arranging carbon made porous material in uniform and zigzag manner on the rib surface of the flow field. The study focuses on enhancing the performance of PEMFC by reducing liquid flooding in the interface between the rib and Gas Diffusion Layer (GDL). A single PEMFC having an active area of 25 cm2, with three flow channel designs (conventional serpentine, pin type flow channel with 2 mm cubical porous inserts in zigzag and uniform pattern) are modeled for the numerical analysis. The effect of porosity of the carbon inserts on the cell performance is studied by varying its value from 0.6 to 0.9. The results show that the performance of the flow channel with zigzag and uniformly positioned porous inserts is more than the conventional serpentine flow channel by 20.36% and 16.87% respectively. The reason for this increase is the removal of the accumulated water from the rib surface due to the capillary action of the porous carbon inserts. This helps in eliminating the stagnant water regions under the rib and thereby helps in reducing liquid flooding.
