Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of fligh...Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].展开更多
In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency...In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency resource.Specifically,to deal with the intra-layer and inter-layer interference of SIP under multi-layer transmission,the interference cancellation with superimposed symbol aided channel estimation is leveraged in the neural receiver,accompanied by the pre-design of pilot code-division orthogonal mechanism at transmitter.In addition,to address the complexity issue for inter-vendor collaboration and the generalization problem in practical deployments,respectively,this paper also provides a fixed SIP(F-SIP)design based on constant pilot power ratio and scalable mechanisms for different modulation and coding schemes(MCSs)and transmission layers.Simulation results demonstrate the superiority of the proposed schemes on the performance of block error rate and throughput compared with existing counterparts.展开更多
Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implement...Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implemented the Pilot Policy on Clean Winter Heating in Northern China,aiming to achieve high central heating coverage and cleaner energy consumption.Studying the effects of this policy can help promote its implementation and serve as a reference for effective adjustment of the contents in the future.However,few studies have investigated this policy and its carbon reduction effects,and most focus on the provincial or city levels.Therefore,this paper considers the policy’s influence on air pollution and carbon emissions at the county level to provide a precise and comprehensive assessment of the policy effects.We use panel data from 1290 counties in 15 provinces in Northern China from 2014 to 2021,applying a multiperiod difference-in-differences model to quantify the impact of the policy on carbon emissions and air quality in the pilot area.We then conduct a series of tests to demonstrate the robustness of the results and analyze the mechanisms of the policy effects from two perspectives,namely,central heating and natural gas use,through a mediating effect model.Finally,we examine the heterogeneity of policy effects between counties based on geographic location and per capita income levels of rural residents through a moderating effect model.The results reveal that the policy significantly reduces air pollution and carbon emissions in the pilot area by increasing the central heating area and natural gas use.Compared with the central and western regions in the north and areas with low-income rural residents,the policy effects in the eastern regions in the north and areas with high-income rural residents are more pronounced.展开更多
Peking Union Medical College(PUMC)launched the"4+4"Medical Doctor(MD)pilot program in 2018,admitting students with non-medical backgrounds from top universities,aligning with national medical talent training...Peking Union Medical College(PUMC)launched the"4+4"Medical Doctor(MD)pilot program in 2018,admitting students with non-medical backgrounds from top universities,aligning with national medical talent training policies to foster diverse and eager learners in medicine.On the occasion of the graduation of the first class of the"4+4"MD pilot class at PUMC in 2023,we reviewed the teaching reform in the pilot program and carried out a systematic survey and interviews with students,faculties,and management staff of the pilot class.This article reports on the measures taken by the pilot class at PUMC in enrollment and curriculum setting,and demonstrates the achievements of the pilot class in terms of student academic background structure,knowledge acquisition and skill learning,scientific research ability,and course evaluation.The results indicated that the pilot class had met the national demand for the"Medicine+X"talent training model.More specifically,with a diverse academic backgrounds,the pilot class graduates had academic levels comparable to the eight-year medical education graduates,and their scientific research abilities were satisfactory.The pilot program at PUMC will optimize the curriculum setting,strengthen the construction of faculty,learning resources,and teaching facilities,and reform the academic evaluation methods,thus deepening the reform of medical education and improving the"4+4"MD program as a novel medical education model.展开更多
Background: Cervical Intraepithelial neoplasia treatments have become essential interventions to manage cervical lesions. Majority of the recipients of these treatments are women within the reproductive age group, who...Background: Cervical Intraepithelial neoplasia treatments have become essential interventions to manage cervical lesions. Majority of the recipients of these treatments are women within the reproductive age group, who according to literature may be at risk of adverse pregnancy outcomes. This pilot study is part of a study investigating adverse pregnancy outcomes among women who received Cryotherapy, Thermal ablation and Loop Electrosurgical Excision Procedure compared to the untreated women in Zambia. Materials and Methods: This descriptive study analyzed records of 886 (n = 443 treated and n = 443 untreated) women aged 15 - 49 years. The women were either screened with Visual Inspection with Acetic Acid or treated for Cervical Intraepithelial neoplasia at the Adult Infectious Disease Centre between January 2010 and December 2020. Women meeting the criteria were identified using the Visual Inspection with Acetic Acid screening records and telephone interviews to obtain the adverse pregnancy outcome experienced. Data were analysed using STATA version 16 to determine the prevalence and obtain frequency distribution of outcomes of interest. Univariate and multivariable binary logistic regression estimated odds of adverse pregnancy outcomes across the three treatments. Results: The respondents were aged 15 to 49 years. Adverse pregnancy outcomes were observed to be more prevalent in the treatment group (18.5%) compared to the untreated group (5.4%). Normal pregnancy outcomes were lower in the treated (46.3%;n = 443) than the untreated (53.7%;n = 443). The treated group accounted for the majority of abortions (85.2%), prolonged labour (85.7%) and low birth weight (80%), whereas, the untreated accounted for the majority of still births (72.7%). Women treated with cryotherapy (aOR = 2.43, 95% CI = 1.32 - 4.49, p = 0.004), thermal ablation (aOR = 6.37, 95% CI = 0.99 - 41.2, p = 0.052) and Loop Electrosurgical Excision Procedure (aOR = 9.67, 95% CI = 2.17 - 43.1, p = 0.003) had two-, six- and ten-times higher odds of adverse pregnancy outcomes respectively, relative to women who required no treatment. Conclusion: Adverse pregnancy outcomes are prevalent among women who have received treatment in Zambia. The findings indicate that treating Cervical Intraepithelial Neoplasia has been linked to higher chances of experiencing abortion, delivering low birth weight babies and enduring prolonged labor that may result in a caesarean section delivery. Cervical neoplasia treatments, particularly Loop Electrosurgical Excision Procedure, are associated with significantly increased odds of adverse pregnancy outcomes. It is essential to include information about prior Cervical Intraepithelial neoplasia treatment outcomes in obstetric care.展开更多
Based on the current situation of the operation and maintenance management of the pilot base in many chemical parks in China,this paper conducts an in-depth exploration of the operation and maintenance management and ...Based on the current situation of the operation and maintenance management of the pilot base in many chemical parks in China,this paper conducts an in-depth exploration of the operation and maintenance management and innovation mode of the pilot base from the aspects of the evaluation of the pilot project entering the park,safety and environmental protection supervision,pilot mode,and industrialization mode of the pilot test results,so as to provide solutions for accelerating the process and industrialization of the pilot project and realizing the innovation value of the pilot base.展开更多
Training-based cellular communication systems use orthogonal pilot sequences to limit pilot contamination.However,the orthogonality constraint imposes a certain pilot length,and therefore,in communication systems with...Training-based cellular communication systems use orthogonal pilot sequences to limit pilot contamination.However,the orthogonality constraint imposes a certain pilot length,and therefore,in communication systems with a large number of users,time-frequency resources are wasted significantly in the training phase.In cellular massive MIMO systems,the time-frequency resources can be used more efficiently by replacing the orthogonal pilots with shorter non-orthogonal pilot sequences in such a way that more space is available for the transmission of additional data symbols,and thus achieving higher data rates.Of course,the use of non-orthogonal pilots introduces additional pilot contamination,so the performance improvement could be achieved under certain system conditions,which are thoroughly investigated in this paper.We first provide a performance analysis framework for the uplink of cellular massive MIMO systems in which the effect of user pilot non-orthogonality has been analytically modelled.In this framework,we derive analytical expressions for the channel estimation,user Signal-to-Interference-plus-Noise-Ratio(SINR),and the average channel capacity per cell.We then use the proposed framework to evaluate the achievable spectral efficiency gain obtained by replacing orthogonal pilots with non-orthogonal counterparts.In particular,the existing trade-off between pilot lengths and the additional data symbols that can be transmitted by reducing the number of pilot symbols,is numerically quantified over a wide range of system parameters.展开更多
[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[M...[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[Methods]P.heterophylla fibrous roots were taken as the matrix material,and Box Behnken design was used to analyze the extraction time,composite enzyme addition amount,and liquid-solid ratio for response surface optimization experiments,and then applied to the pilot extraction of P.heterophylla fibrous roots.[Results]Response surface analysis showed that all factors had a significant impact on the experimental indicators.The optimal extraction process conditions for polysaccharides from P.heterophylla fibrous roots were extraction time of 2.7 h,compound enzyme addition of 2.5%,and liquid-solid ratio of 32.The yield of polysaccharides from P.heterophylla fibrous roots was 4.83%.The water extraction process of P.heterophylla fibrous roots extraction pilot was used as the control group for response surface optimization of the pilot experiment.The optimization results showed that the extraction time was 3 h,the amount of composite enzyme added was 2.5%,and the liquid-solid ratio was 28.The polysaccharide yield was 4.75%,an increase of 4.63%compared to the control group.[Conclusions]This paper could provide feasibility for the innovation of enzy-matic hydrolysis technology for P.heterophylla fibrous roots and its workshop pilot practice application,as well as a reference for the industrial application of its medicinal resources.展开更多
Since the 18th National Congress of the Communist Party of China,the country has established 21 Free Trade Pilot Zones(FTZs),achieving significant pioneering results in reform and opening up and creating a strong demo...Since the 18th National Congress of the Communist Party of China,the country has established 21 Free Trade Pilot Zones(FTZs),achieving significant pioneering results in reform and opening up and creating a strong demonstrative effect nationwide.The basic experience from a decade of FTZs includes:adhering to the centralized and unified leadership of the CPC Central Committee;combining top-level design with encouragement of grassroots innovation;leveraging the distinct characteristics and strengths of FTZs to form a differentiated development pattern;maintaining the integration of opening up with domestic reforms;using openness to drive reforms;and organically combining openness with national security assurance.Under the current and future new circumstances,China’s FTZs face new challenges and tasks.In accordance with the directives of the 20th National Congress of the Communist Party of China,an enhancement strategy for the FTZs needs to be implemented.This involves the following:First,accurately understanding and responding to the changing situation to create strategic opportunities.Second,shifting paradigms to implement innovation-driven strategies,using the new development pattern concept to guide the reform experiments and construction of the FTZs.Third,granting more autonomy to FTZs for reforms,pursuing progress while maintaining stability,and solidly advancing the reform experiments in the FTZs.Fourth,orderly expanding the opening up of the service sector and cautiously advancing the internationalization of the renminbi.Fifth,promoting innovative development in trade to build a strong trade nation.Sixth,establishing synergy with bilateral FTZs,Belt and Road cooperation,and national diplomatic strategies to enhance the linkage effect.展开更多
This manuscript presents a research proposal to investigate how hazardous attitudes among general aviation pilots influence pilot performance in aviation accidents. General aviation pilots train to maintain safe flyin...This manuscript presents a research proposal to investigate how hazardous attitudes among general aviation pilots influence pilot performance in aviation accidents. General aviation pilots train to maintain safe flying conditions, but accidents still occur, and human factors figure prominently among the causes of aviation accidents. The levels of hazardous attitudes among pilots may influence the likelihood of engaging in risky flight behaviors that can lead to accidents. This quantitative study aims to determine whether dangerous attitudes impact risk perception in general aviation pilots. The study will focus on two specific hazardous attitudes, “Anti-Authority” and Macho” behaviors. Among the hazardous attitudes identified by the Federal Aviation Administration (FAA), the two attitudes often stand out in accident investigations and pilot narratives. While all hazardous attitudes have inherent dangers, these two attitudes tend to be more frequently cited in accident reports and investigations. Despite rigorous training in safe flying conditions, general aviation accidents still transpire due to human factors. This research hypothesizes that the five attitudes from the hazardous attitude model, particularly Anti-Authority and Macho, significantly shape pilots’ risk perception. The insights from this study would benefit stakeholders, like the Aircraft Owners and Pilots Association (AOPA), Air Safety Institute, and aviation training programs, in creating training modules tailored to reduce such attitudes.展开更多
针对现有信道估计方案导致正交时频空间(Orthogonal Time Frequency Space,OTFS)调制系统峰均功率比(Peak-to-Average Power Ratio,PAPR)高或频谱效率(Spectral Efficiency,SE)低的问题,提出一种多叠加导频的低PAPR、高SE信道估计方法...针对现有信道估计方案导致正交时频空间(Orthogonal Time Frequency Space,OTFS)调制系统峰均功率比(Peak-to-Average Power Ratio,PAPR)高或频谱效率(Spectral Efficiency,SE)低的问题,提出一种多叠加导频的低PAPR、高SE信道估计方法。发送端利用时域正交性和离散傅里叶域相位的随机性,在时延多普勒域中嵌入与数据相叠加的5导频符号的导频图案实现低PAPR,提高SE。接收端以数据符号与噪声之和的能量均值为基准,实现导频信号检测,同时根据每个导频的不同位置信息恢复出存在相位旋转的数据信号。基于能量准则,利用多个独立的接收信号进行联合信道估计,以降低数据符号的干扰,并采用消息传递算法进行数据恢复。仿真结果表明,该方法比单叠加导频信道估计的PAPR低,同时较嵌入式导频信道估计的SE提高约14.4%。展开更多
基金supported by the Military Medical Science and Technology Youth Cultivation Program of the Chinese PLA(17QNP023)the Key Projects of Medical Service Scientific Research of the Navy Medical Center(20M2302)the Military Logistics National Military Standard General Project of Chinese PLA(BHJ22B002).
文摘Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].
文摘In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency resource.Specifically,to deal with the intra-layer and inter-layer interference of SIP under multi-layer transmission,the interference cancellation with superimposed symbol aided channel estimation is leveraged in the neural receiver,accompanied by the pre-design of pilot code-division orthogonal mechanism at transmitter.In addition,to address the complexity issue for inter-vendor collaboration and the generalization problem in practical deployments,respectively,this paper also provides a fixed SIP(F-SIP)design based on constant pilot power ratio and scalable mechanisms for different modulation and coding schemes(MCSs)and transmission layers.Simulation results demonstrate the superiority of the proposed schemes on the performance of block error rate and throughput compared with existing counterparts.
基金supported by the National Social Science Fund of China[Grant No.21BGL181]to Yan Chen.
文摘Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implemented the Pilot Policy on Clean Winter Heating in Northern China,aiming to achieve high central heating coverage and cleaner energy consumption.Studying the effects of this policy can help promote its implementation and serve as a reference for effective adjustment of the contents in the future.However,few studies have investigated this policy and its carbon reduction effects,and most focus on the provincial or city levels.Therefore,this paper considers the policy’s influence on air pollution and carbon emissions at the county level to provide a precise and comprehensive assessment of the policy effects.We use panel data from 1290 counties in 15 provinces in Northern China from 2014 to 2021,applying a multiperiod difference-in-differences model to quantify the impact of the policy on carbon emissions and air quality in the pilot area.We then conduct a series of tests to demonstrate the robustness of the results and analyze the mechanisms of the policy effects from two perspectives,namely,central heating and natural gas use,through a mediating effect model.Finally,we examine the heterogeneity of policy effects between counties based on geographic location and per capita income levels of rural residents through a moderating effect model.The results reveal that the policy significantly reduces air pollution and carbon emissions in the pilot area by increasing the central heating area and natural gas use.Compared with the central and western regions in the north and areas with low-income rural residents,the policy effects in the eastern regions in the north and areas with high-income rural residents are more pronounced.
文摘Peking Union Medical College(PUMC)launched the"4+4"Medical Doctor(MD)pilot program in 2018,admitting students with non-medical backgrounds from top universities,aligning with national medical talent training policies to foster diverse and eager learners in medicine.On the occasion of the graduation of the first class of the"4+4"MD pilot class at PUMC in 2023,we reviewed the teaching reform in the pilot program and carried out a systematic survey and interviews with students,faculties,and management staff of the pilot class.This article reports on the measures taken by the pilot class at PUMC in enrollment and curriculum setting,and demonstrates the achievements of the pilot class in terms of student academic background structure,knowledge acquisition and skill learning,scientific research ability,and course evaluation.The results indicated that the pilot class had met the national demand for the"Medicine+X"talent training model.More specifically,with a diverse academic backgrounds,the pilot class graduates had academic levels comparable to the eight-year medical education graduates,and their scientific research abilities were satisfactory.The pilot program at PUMC will optimize the curriculum setting,strengthen the construction of faculty,learning resources,and teaching facilities,and reform the academic evaluation methods,thus deepening the reform of medical education and improving the"4+4"MD program as a novel medical education model.
文摘Background: Cervical Intraepithelial neoplasia treatments have become essential interventions to manage cervical lesions. Majority of the recipients of these treatments are women within the reproductive age group, who according to literature may be at risk of adverse pregnancy outcomes. This pilot study is part of a study investigating adverse pregnancy outcomes among women who received Cryotherapy, Thermal ablation and Loop Electrosurgical Excision Procedure compared to the untreated women in Zambia. Materials and Methods: This descriptive study analyzed records of 886 (n = 443 treated and n = 443 untreated) women aged 15 - 49 years. The women were either screened with Visual Inspection with Acetic Acid or treated for Cervical Intraepithelial neoplasia at the Adult Infectious Disease Centre between January 2010 and December 2020. Women meeting the criteria were identified using the Visual Inspection with Acetic Acid screening records and telephone interviews to obtain the adverse pregnancy outcome experienced. Data were analysed using STATA version 16 to determine the prevalence and obtain frequency distribution of outcomes of interest. Univariate and multivariable binary logistic regression estimated odds of adverse pregnancy outcomes across the three treatments. Results: The respondents were aged 15 to 49 years. Adverse pregnancy outcomes were observed to be more prevalent in the treatment group (18.5%) compared to the untreated group (5.4%). Normal pregnancy outcomes were lower in the treated (46.3%;n = 443) than the untreated (53.7%;n = 443). The treated group accounted for the majority of abortions (85.2%), prolonged labour (85.7%) and low birth weight (80%), whereas, the untreated accounted for the majority of still births (72.7%). Women treated with cryotherapy (aOR = 2.43, 95% CI = 1.32 - 4.49, p = 0.004), thermal ablation (aOR = 6.37, 95% CI = 0.99 - 41.2, p = 0.052) and Loop Electrosurgical Excision Procedure (aOR = 9.67, 95% CI = 2.17 - 43.1, p = 0.003) had two-, six- and ten-times higher odds of adverse pregnancy outcomes respectively, relative to women who required no treatment. Conclusion: Adverse pregnancy outcomes are prevalent among women who have received treatment in Zambia. The findings indicate that treating Cervical Intraepithelial Neoplasia has been linked to higher chances of experiencing abortion, delivering low birth weight babies and enduring prolonged labor that may result in a caesarean section delivery. Cervical neoplasia treatments, particularly Loop Electrosurgical Excision Procedure, are associated with significantly increased odds of adverse pregnancy outcomes. It is essential to include information about prior Cervical Intraepithelial neoplasia treatment outcomes in obstetric care.
文摘Based on the current situation of the operation and maintenance management of the pilot base in many chemical parks in China,this paper conducts an in-depth exploration of the operation and maintenance management and innovation mode of the pilot base from the aspects of the evaluation of the pilot project entering the park,safety and environmental protection supervision,pilot mode,and industrialization mode of the pilot test results,so as to provide solutions for accelerating the process and industrialization of the pilot project and realizing the innovation value of the pilot base.
文摘Training-based cellular communication systems use orthogonal pilot sequences to limit pilot contamination.However,the orthogonality constraint imposes a certain pilot length,and therefore,in communication systems with a large number of users,time-frequency resources are wasted significantly in the training phase.In cellular massive MIMO systems,the time-frequency resources can be used more efficiently by replacing the orthogonal pilots with shorter non-orthogonal pilot sequences in such a way that more space is available for the transmission of additional data symbols,and thus achieving higher data rates.Of course,the use of non-orthogonal pilots introduces additional pilot contamination,so the performance improvement could be achieved under certain system conditions,which are thoroughly investigated in this paper.We first provide a performance analysis framework for the uplink of cellular massive MIMO systems in which the effect of user pilot non-orthogonality has been analytically modelled.In this framework,we derive analytical expressions for the channel estimation,user Signal-to-Interference-plus-Noise-Ratio(SINR),and the average channel capacity per cell.We then use the proposed framework to evaluate the achievable spectral efficiency gain obtained by replacing orthogonal pilots with non-orthogonal counterparts.In particular,the existing trade-off between pilot lengths and the additional data symbols that can be transmitted by reducing the number of pilot symbols,is numerically quantified over a wide range of system parameters.
基金Supported by Special Project of Central Leading Local Science and Technology Development(202113030)Regional Development Project of Fujian Provincial Science and Technology Plan(2022N3017).
文摘[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[Methods]P.heterophylla fibrous roots were taken as the matrix material,and Box Behnken design was used to analyze the extraction time,composite enzyme addition amount,and liquid-solid ratio for response surface optimization experiments,and then applied to the pilot extraction of P.heterophylla fibrous roots.[Results]Response surface analysis showed that all factors had a significant impact on the experimental indicators.The optimal extraction process conditions for polysaccharides from P.heterophylla fibrous roots were extraction time of 2.7 h,compound enzyme addition of 2.5%,and liquid-solid ratio of 32.The yield of polysaccharides from P.heterophylla fibrous roots was 4.83%.The water extraction process of P.heterophylla fibrous roots extraction pilot was used as the control group for response surface optimization of the pilot experiment.The optimization results showed that the extraction time was 3 h,the amount of composite enzyme added was 2.5%,and the liquid-solid ratio was 28.The polysaccharide yield was 4.75%,an increase of 4.63%compared to the control group.[Conclusions]This paper could provide feasibility for the innovation of enzy-matic hydrolysis technology for P.heterophylla fibrous roots and its workshop pilot practice application,as well as a reference for the industrial application of its medicinal resources.
文摘Since the 18th National Congress of the Communist Party of China,the country has established 21 Free Trade Pilot Zones(FTZs),achieving significant pioneering results in reform and opening up and creating a strong demonstrative effect nationwide.The basic experience from a decade of FTZs includes:adhering to the centralized and unified leadership of the CPC Central Committee;combining top-level design with encouragement of grassroots innovation;leveraging the distinct characteristics and strengths of FTZs to form a differentiated development pattern;maintaining the integration of opening up with domestic reforms;using openness to drive reforms;and organically combining openness with national security assurance.Under the current and future new circumstances,China’s FTZs face new challenges and tasks.In accordance with the directives of the 20th National Congress of the Communist Party of China,an enhancement strategy for the FTZs needs to be implemented.This involves the following:First,accurately understanding and responding to the changing situation to create strategic opportunities.Second,shifting paradigms to implement innovation-driven strategies,using the new development pattern concept to guide the reform experiments and construction of the FTZs.Third,granting more autonomy to FTZs for reforms,pursuing progress while maintaining stability,and solidly advancing the reform experiments in the FTZs.Fourth,orderly expanding the opening up of the service sector and cautiously advancing the internationalization of the renminbi.Fifth,promoting innovative development in trade to build a strong trade nation.Sixth,establishing synergy with bilateral FTZs,Belt and Road cooperation,and national diplomatic strategies to enhance the linkage effect.
文摘This manuscript presents a research proposal to investigate how hazardous attitudes among general aviation pilots influence pilot performance in aviation accidents. General aviation pilots train to maintain safe flying conditions, but accidents still occur, and human factors figure prominently among the causes of aviation accidents. The levels of hazardous attitudes among pilots may influence the likelihood of engaging in risky flight behaviors that can lead to accidents. This quantitative study aims to determine whether dangerous attitudes impact risk perception in general aviation pilots. The study will focus on two specific hazardous attitudes, “Anti-Authority” and Macho” behaviors. Among the hazardous attitudes identified by the Federal Aviation Administration (FAA), the two attitudes often stand out in accident investigations and pilot narratives. While all hazardous attitudes have inherent dangers, these two attitudes tend to be more frequently cited in accident reports and investigations. Despite rigorous training in safe flying conditions, general aviation accidents still transpire due to human factors. This research hypothesizes that the five attitudes from the hazardous attitude model, particularly Anti-Authority and Macho, significantly shape pilots’ risk perception. The insights from this study would benefit stakeholders, like the Aircraft Owners and Pilots Association (AOPA), Air Safety Institute, and aviation training programs, in creating training modules tailored to reduce such attitudes.
文摘针对现有信道估计方案导致正交时频空间(Orthogonal Time Frequency Space,OTFS)调制系统峰均功率比(Peak-to-Average Power Ratio,PAPR)高或频谱效率(Spectral Efficiency,SE)低的问题,提出一种多叠加导频的低PAPR、高SE信道估计方法。发送端利用时域正交性和离散傅里叶域相位的随机性,在时延多普勒域中嵌入与数据相叠加的5导频符号的导频图案实现低PAPR,提高SE。接收端以数据符号与噪声之和的能量均值为基准,实现导频信号检测,同时根据每个导频的不同位置信息恢复出存在相位旋转的数据信号。基于能量准则,利用多个独立的接收信号进行联合信道估计,以降低数据符号的干扰,并采用消息传递算法进行数据恢复。仿真结果表明,该方法比单叠加导频信道估计的PAPR低,同时较嵌入式导频信道估计的SE提高约14.4%。
