Objectives: This study aims to investigate the status of knowledge, attitude and practice (KAP) of oral health among medical undergraduate students, and provide reference for implementing oral health interventions. Me...Objectives: This study aims to investigate the status of knowledge, attitude and practice (KAP) of oral health among medical undergraduate students, and provide reference for implementing oral health interventions. Methods: A total of 528 undergraduate students enrolled in Fuzhou Medical College from February 2023 to September 2023 were selected as the research subjects. Their oral health KAP were investigated, and the oral health behavior habits of different types of medical students were compared, and possible influencing factors were analyzed. Results: The total awareness rate of oral health knowledge among medical students is 77.0%, with an average score of 3.85 ± 1.16 points. The overall positive rate of oral health attitudes among medical students is 80.0%, with an average score of 3.19 ± 0.72 points. The total qualified rate of oral health behavior is 65.9%, with an average score of 4.61 ± 1.23 points. The scores of oral health knowledge, attitudes, and behaviors among medical students are related to gender, major, smoking status, and oral health status. The frequency of brushing teeth in the female group was higher than that in the male group, while the habit of brushing teeth before bedtime and the frequency of timely replacement of toothbrushes when deformed were lower, with statistical significance (p 0.05). The frequency of timely replacement of toothbrushes varies among medical students from different majors, and the difference is statistically significant (p 0.05). People who have a habit of eating hot and cold food have a higher frequency of brushing their teeth every day, and the difference is statistically significant (p 0.05). Non smokers have a better habit of brushing their teeth before bedtime and a higher frequency of timely replacement when their toothbrush deforms, with a statistically significant difference (p 0.05). The frequency of using fluoride toothpaste or medicated toothpaste, having a habit of unilateral chewing, and timely replacement of toothbrushes when deformed in patients with existing oral problems is higher than that of those without oral problems, and the difference is statistically significant (p 0.05). Conclusion: The knowledge, attitude, and behavior of oral health among medical students in this school are above average. Students with different genders, dietary and smoking habits, and oral health status have different oral health behavioral habits. It is recommended to include oral health education in mandatory courses for various medical majors.展开更多
针对太赫兹频段高速移动场景,提出了一种参考信号方案——增强型离散傅里叶变换扩展正交频分复用(E DFT-s-OFDM)DMRS:将具有循环前缀(CP)和循环后缀(CS)的参考信号序列分割为首部和尾部参考信号序列,然后分别嵌入每个OFDM符号的尾部和...针对太赫兹频段高速移动场景,提出了一种参考信号方案——增强型离散傅里叶变换扩展正交频分复用(E DFT-s-OFDM)DMRS:将具有循环前缀(CP)和循环后缀(CS)的参考信号序列分割为首部和尾部参考信号序列,然后分别嵌入每个OFDM符号的尾部和首部。这种方案的优点在于,前一个OFDM符号的尾部和后一个OFDM符号的首部构成一个完整的参考信号序列,从而允许接收端在每个OFDM符号间隔内都能进行信道估计,提高了信道估计的精度和实时性。此外,相邻OFDM符号的首部和尾部参考信号序列相同,从而省去了每个OFDM符号的传统循环前缀(CP),提高了频谱效率。仿真结果表明,在太赫兹频段高速移动场景下,与5G NR DFT-s-OFDM波形的DMRS方案相比,该方案的信道估计更精确,通信系统的频谱效率更高。展开更多
为探究成渝地区双城经济圈NPP时空变化及与气候的关系,基于MOD17A3产品NPP数据,采用一元线性回归模型模拟2001—2020年植被NPP演变趋势,分析植被NPP变化特征,结合ANUSPLIN插值的气象数据,采用相关性分析法定量分析气候变化对研究区植被...为探究成渝地区双城经济圈NPP时空变化及与气候的关系,基于MOD17A3产品NPP数据,采用一元线性回归模型模拟2001—2020年植被NPP演变趋势,分析植被NPP变化特征,结合ANUSPLIN插值的气象数据,采用相关性分析法定量分析气候变化对研究区植被NPP变化的影响。研究表明:(1)研究区内植被NPP整体呈现缓慢增长的趋势,增长率为7.53 g C·m^(-2)·a^(-1),同时植被NPP均值分布呈现四周高中间低的空间格局。(2)研究区内气候因子对植被NPP变化的影响存在空间异质性,在眉山市、乐山市、雅安市以及重庆市黔江区、彭水县部分地区气温与植被NPP负相关关系明显,其呈正相关关系的区域广泛分布在成渝城市群的中部和东部;降水与植被NPP呈正相关关系的区域面积占比达到92.46%。(3)研究区主要受非气候因子影响,面积占比高达86.87%,说明人类活动对植被NPP变化的影响愈来愈烈,研究人为影响应是成渝城市群生态修复的重点。展开更多
太赫兹通信是未来6G中业界关注的重要场景之一。太赫兹频段可以支持超大带宽和超高速率的无线通信,目前3GPP协议中的正交频分复用(Orthogonal Frequency Division Multiplex, OFDM)技术使用支持的最大子载波间隔和最大快速傅里叶逆变换(...太赫兹通信是未来6G中业界关注的重要场景之一。太赫兹频段可以支持超大带宽和超高速率的无线通信,目前3GPP协议中的正交频分复用(Orthogonal Frequency Division Multiplex, OFDM)技术使用支持的最大子载波间隔和最大快速傅里叶逆变换(Inverse Fast Fourier Transform, IFFT)点数不足以满足太赫兹场景超大带宽的需求。提出了一种新的波形方案:广义滤波器组-正交频分复用(Generalized Filter Bank Orthogonal Frequency Division Multiplexing, GFB-OFDM)波形,可以将原有的大点数IFFT分解成两级小点数的IFFT,以支持更大的传输带宽。GFB-OFDM还可以灵活地支持不同子载波间隔、不同数据类型的联合处理,以实现不同业务类型的传输。GFB-OFDM在接收端仍然可以采用传统的循环前缀正交频分复用(Cyclic Prefix Orthogonal Frequency Division Multiplexing, CP-OFDM)接收方法,仿真结果表明GFB-OFDM的综合性能优于CP-OFDM。展开更多
Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at provi...Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic nanomaterials.The fundamental con-cepts and principles of Sn_(3)O_(4)are introduced.Sn_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic reactions.Subsequently,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are discussed.Morphology control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)materials.The effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)nanomaterials.Furthermore,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic sensors.The discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and functionalities.Finally,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based nanomaterials.Through the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.展开更多
NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy leve...NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.展开更多
文摘Objectives: This study aims to investigate the status of knowledge, attitude and practice (KAP) of oral health among medical undergraduate students, and provide reference for implementing oral health interventions. Methods: A total of 528 undergraduate students enrolled in Fuzhou Medical College from February 2023 to September 2023 were selected as the research subjects. Their oral health KAP were investigated, and the oral health behavior habits of different types of medical students were compared, and possible influencing factors were analyzed. Results: The total awareness rate of oral health knowledge among medical students is 77.0%, with an average score of 3.85 ± 1.16 points. The overall positive rate of oral health attitudes among medical students is 80.0%, with an average score of 3.19 ± 0.72 points. The total qualified rate of oral health behavior is 65.9%, with an average score of 4.61 ± 1.23 points. The scores of oral health knowledge, attitudes, and behaviors among medical students are related to gender, major, smoking status, and oral health status. The frequency of brushing teeth in the female group was higher than that in the male group, while the habit of brushing teeth before bedtime and the frequency of timely replacement of toothbrushes when deformed were lower, with statistical significance (p 0.05). The frequency of timely replacement of toothbrushes varies among medical students from different majors, and the difference is statistically significant (p 0.05). People who have a habit of eating hot and cold food have a higher frequency of brushing their teeth every day, and the difference is statistically significant (p 0.05). Non smokers have a better habit of brushing their teeth before bedtime and a higher frequency of timely replacement when their toothbrush deforms, with a statistically significant difference (p 0.05). The frequency of using fluoride toothpaste or medicated toothpaste, having a habit of unilateral chewing, and timely replacement of toothbrushes when deformed in patients with existing oral problems is higher than that of those without oral problems, and the difference is statistically significant (p 0.05). Conclusion: The knowledge, attitude, and behavior of oral health among medical students in this school are above average. Students with different genders, dietary and smoking habits, and oral health status have different oral health behavioral habits. It is recommended to include oral health education in mandatory courses for various medical majors.
文摘针对太赫兹频段高速移动场景,提出了一种参考信号方案——增强型离散傅里叶变换扩展正交频分复用(E DFT-s-OFDM)DMRS:将具有循环前缀(CP)和循环后缀(CS)的参考信号序列分割为首部和尾部参考信号序列,然后分别嵌入每个OFDM符号的尾部和首部。这种方案的优点在于,前一个OFDM符号的尾部和后一个OFDM符号的首部构成一个完整的参考信号序列,从而允许接收端在每个OFDM符号间隔内都能进行信道估计,提高了信道估计的精度和实时性。此外,相邻OFDM符号的首部和尾部参考信号序列相同,从而省去了每个OFDM符号的传统循环前缀(CP),提高了频谱效率。仿真结果表明,在太赫兹频段高速移动场景下,与5G NR DFT-s-OFDM波形的DMRS方案相比,该方案的信道估计更精确,通信系统的频谱效率更高。
文摘为探究成渝地区双城经济圈NPP时空变化及与气候的关系,基于MOD17A3产品NPP数据,采用一元线性回归模型模拟2001—2020年植被NPP演变趋势,分析植被NPP变化特征,结合ANUSPLIN插值的气象数据,采用相关性分析法定量分析气候变化对研究区植被NPP变化的影响。研究表明:(1)研究区内植被NPP整体呈现缓慢增长的趋势,增长率为7.53 g C·m^(-2)·a^(-1),同时植被NPP均值分布呈现四周高中间低的空间格局。(2)研究区内气候因子对植被NPP变化的影响存在空间异质性,在眉山市、乐山市、雅安市以及重庆市黔江区、彭水县部分地区气温与植被NPP负相关关系明显,其呈正相关关系的区域广泛分布在成渝城市群的中部和东部;降水与植被NPP呈正相关关系的区域面积占比达到92.46%。(3)研究区主要受非气候因子影响,面积占比高达86.87%,说明人类活动对植被NPP变化的影响愈来愈烈,研究人为影响应是成渝城市群生态修复的重点。
文摘太赫兹通信是未来6G中业界关注的重要场景之一。太赫兹频段可以支持超大带宽和超高速率的无线通信,目前3GPP协议中的正交频分复用(Orthogonal Frequency Division Multiplex, OFDM)技术使用支持的最大子载波间隔和最大快速傅里叶逆变换(Inverse Fast Fourier Transform, IFFT)点数不足以满足太赫兹场景超大带宽的需求。提出了一种新的波形方案:广义滤波器组-正交频分复用(Generalized Filter Bank Orthogonal Frequency Division Multiplexing, GFB-OFDM)波形,可以将原有的大点数IFFT分解成两级小点数的IFFT,以支持更大的传输带宽。GFB-OFDM还可以灵活地支持不同子载波间隔、不同数据类型的联合处理,以实现不同业务类型的传输。GFB-OFDM在接收端仍然可以采用传统的循环前缀正交频分复用(Cyclic Prefix Orthogonal Frequency Division Multiplexing, CP-OFDM)接收方法,仿真结果表明GFB-OFDM的综合性能优于CP-OFDM。
基金the National Natural Science Foundation of China(No.52272212)the Natural Science Foundation of Shandong Province(Nos.ZR2022JQ20 and ZR2023MB126)+2 种基金the Taishan Scholar Project of Shandong Province(No.tsqn202211168)the Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science,MOE(No.M2022-7)the STIEI scientific research funding project(No.GCC2023036).
文摘Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic nanomaterials.The fundamental con-cepts and principles of Sn_(3)O_(4)are introduced.Sn_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic reactions.Subsequently,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are discussed.Morphology control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)materials.The effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)nanomaterials.Furthermore,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic sensors.The discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and functionalities.Finally,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based nanomaterials.Through the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.
文摘NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.
