For decades,the so-called Peking Man(Homo erectus pekinensis)at Zhoukoudian has been considered to be a hominin that engaged in the controlled production and management of fire.However,relatively recent analyses have ...For decades,the so-called Peking Man(Homo erectus pekinensis)at Zhoukoudian has been considered to be a hominin that engaged in the controlled production and management of fire.However,relatively recent analyses have cast doubt on this assertion.The most compelling reason for this doubt was the absence of siliceous aggregates in the Zhoukoudian deposits.This study presents evidence establishing the controlled use of fire by Homo erectus pekinensis through analyses of four soil samples sourced from Layers 4 and 6 at Zhoukoudian Locality 1.These results demonstrate that all four specimens contain siliceous aggregates as well as elemental carbon,and the potassium content of the insoluble residues of these specimens ranges between 1.21%and 2.94%.The analyses provide strong evidence of the in situ use of fire by Homo erectus pekinensis.展开更多
A full-scale experimental research is conducted on the fire fume refluence of a sloped long and large curved tunnel in the underground plant of a hydraulic and hydropower engineering project under three different fire...A full-scale experimental research is conducted on the fire fume refluence of a sloped long and large curved tunnel in the underground plant of a hydraulic and hydropower engineering project under three different fire powers.As a result,the eddy effect and pattern of the fire fume flow in the tunnel in case of fire is discovered and the refluence of the fume layers in case of fire is observed.Through analysis of the temperature measurement resulted in the course of the experiment,the main characteristics and performance of the fire fume refluence are discussed under the three different fire powers.展开更多
Since the outbreak of the coronavirus disease 2019(COVID-19)epidemic in 2019,the public health system has faced enormous challenges.Tracking the individuals who test positive for severe acute respiratory syndrome coro...Since the outbreak of the coronavirus disease 2019(COVID-19)epidemic in 2019,the public health system has faced enormous challenges.Tracking the individuals who test positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is a key step for interrupting chains of transmission of SARS-CoV-2 and reducing COVID-19-associated mortality.With the increasing of asymptomatic infections,it is difficult to track asymptomatic infections through epidemiological surveys and virus whole-genome sequencing.However,due to the cross-reactivity of neutralizing antibodies produced by multiple virus subtypes,neutralizing antibody detection cannot be used to determine whether an individual has a history of infection with a specific subtype of SARS-CoV-2.We recruited 4 human leukocyte antigen A2(HLA-A2)infections,15 individuals who received three doses of inactivated vaccines,and 30 breakthrough infections after vaccination and discussed a case-tracking approach to detect epitope-specific CD8^(+)T cells in the peripheral blood of close contacts,including accurate HLA typing based on ribonucleic acid(RNA)-sequencing and flow cytometry data and the comparison and characterization of SARS-CoV-2 HLA-A2 and HLA-A24 epitope-specific CD8^(+)T cells.From individuals who received three doses of inactivated vaccine,we observed that the CD8^(+)T cell specificity for ancestral epitopes was significantly higher than for mutated epitopes,and the fold change of CD8^(+)T cells corresponding to mutated epitopes relative to ancestral epitopes was less than 1.The enzyme-linked immunospot(ELISpot)results further validate this result.This study forms a“method for understanding the infection history of SARS-CoV-2 subtypes based on the proportion of epitope-specific CD8^(+)T cells in the peripheral blood of subjects”,covering up to 46%of the population,including HLA-A2+and HLA-A24+donors,providing a novel method for SARS-CoV-2 infected case tracing.展开更多
为研究大型机加车间噪声减噪工程现状效果和特点,选取某大型机加车间数控机床为研究对象,对其进行减噪工程治理,现场实测了治理前和治理后的噪声数据,并对噪声测量结果进行分析。研究结果表明:数控机床操作人员8 h连续等效A声级从治理前...为研究大型机加车间噪声减噪工程现状效果和特点,选取某大型机加车间数控机床为研究对象,对其进行减噪工程治理,现场实测了治理前和治理后的噪声数据,并对噪声测量结果进行分析。研究结果表明:数控机床操作人员8 h连续等效A声级从治理前的89.2 d B(A),降到治理后的74.3 d B(A),降低了16.7%.;数控机床操作岗位位置测点,在加工1个机件的测量时间段里,噪声值从治理前的85.9 d B(A),降到治理后的55.1 d B(A),降低了33.85%;对机加车间现场布置了67个测点,在加工1个机件的测量时间段里进行测量,得到该车间噪声治理前和治理后噪声分布图;对数控机床减噪工程治理前和治理后的频谱进行了分析,得出治理前和治理后各自的最大声级所在频段不随距离的改变而改变,高频减噪效果显著。展开更多
By considering mandatory lane-changing as a collision avoidance measure,this paper presented the corresponding lane-change decision making and trajectory planning algorithm under an emergency scenario.Different from t...By considering mandatory lane-changing as a collision avoidance measure,this paper presented the corresponding lane-change decision making and trajectory planning algorithm under an emergency scenario.Different from the traditional algorithm in which lane-change decision making and trajectory planning are separated,they are here coupled in a proposed algorithm and the related parameters are dynamically adjusted in the whole process.In addition to lane-change collision avoidance feasibility analysis,lanechange time instance and duration time are obtained by solving the constrained convex quadratic optimization programme.By taking lane-change time instance and duration time as inputs,the algorithm then proceeded to propose a kinematic model-based highorder polynomial lane change trajectory.By giving the simulation result compassion with the related algorithm,it is proved that the proposed algorithm has a good robustness and high efficiency.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA05130202)was identified as a Major Basic Research Project of the Ministry of Science and Technology of China(2007FY110200)Support was also received from the State Administration of Work Safety
文摘For decades,the so-called Peking Man(Homo erectus pekinensis)at Zhoukoudian has been considered to be a hominin that engaged in the controlled production and management of fire.However,relatively recent analyses have cast doubt on this assertion.The most compelling reason for this doubt was the absence of siliceous aggregates in the Zhoukoudian deposits.This study presents evidence establishing the controlled use of fire by Homo erectus pekinensis through analyses of four soil samples sourced from Layers 4 and 6 at Zhoukoudian Locality 1.These results demonstrate that all four specimens contain siliceous aggregates as well as elemental carbon,and the potassium content of the insoluble residues of these specimens ranges between 1.21%and 2.94%.The analyses provide strong evidence of the in situ use of fire by Homo erectus pekinensis.
基金supported by the National Natural Science Foundation of China(Grant Nos.505791000,51074143,91024014 and 91024022)the China Research for the 11th Five-year Plan(Grant No. 2008BAB29B06)
文摘A full-scale experimental research is conducted on the fire fume refluence of a sloped long and large curved tunnel in the underground plant of a hydraulic and hydropower engineering project under three different fire powers.As a result,the eddy effect and pattern of the fire fume flow in the tunnel in case of fire is discovered and the refluence of the fume layers in case of fire is observed.Through analysis of the temperature measurement resulted in the course of the experiment,the main characteristics and performance of the fire fume refluence are discussed under the three different fire powers.
基金the Key Project of Shenzhen Science and Technology Innovation Commission(JCYJ20210324115411030)Natural Science Foundation of China(92169102)+10 种基金R&D Program of Guangzhou Laboratory(SRPG22-006)Sanming Project of Medicine in Shenzhen(SZSM202211023)GuangDong Basic and Applied Basic Research Foundation(2022B1515120043)the Open Project Fund of Guangdong Provincial People’s Hospital(YKY-KF202208)National Natural Science Foundation of China(81902097)Funding by Science and Technology Projects in Guangzhou(SL2023A04J01160)the Guangdong Basic andApplied Basic Research Foundation(2023A1515140117)the fellowship of China Postdoctoral Science Foundation(2023TQ0136,2023M741379)supported by grants from the National Key Research and Development Plan(2023YFE0118700,2021YFC2301604)the Fundamental Research Funds for the Central Q4 Universities(21623406).
文摘Since the outbreak of the coronavirus disease 2019(COVID-19)epidemic in 2019,the public health system has faced enormous challenges.Tracking the individuals who test positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is a key step for interrupting chains of transmission of SARS-CoV-2 and reducing COVID-19-associated mortality.With the increasing of asymptomatic infections,it is difficult to track asymptomatic infections through epidemiological surveys and virus whole-genome sequencing.However,due to the cross-reactivity of neutralizing antibodies produced by multiple virus subtypes,neutralizing antibody detection cannot be used to determine whether an individual has a history of infection with a specific subtype of SARS-CoV-2.We recruited 4 human leukocyte antigen A2(HLA-A2)infections,15 individuals who received three doses of inactivated vaccines,and 30 breakthrough infections after vaccination and discussed a case-tracking approach to detect epitope-specific CD8^(+)T cells in the peripheral blood of close contacts,including accurate HLA typing based on ribonucleic acid(RNA)-sequencing and flow cytometry data and the comparison and characterization of SARS-CoV-2 HLA-A2 and HLA-A24 epitope-specific CD8^(+)T cells.From individuals who received three doses of inactivated vaccine,we observed that the CD8^(+)T cell specificity for ancestral epitopes was significantly higher than for mutated epitopes,and the fold change of CD8^(+)T cells corresponding to mutated epitopes relative to ancestral epitopes was less than 1.The enzyme-linked immunospot(ELISpot)results further validate this result.This study forms a“method for understanding the infection history of SARS-CoV-2 subtypes based on the proportion of epitope-specific CD8^(+)T cells in the peripheral blood of subjects”,covering up to 46%of the population,including HLA-A2+and HLA-A24+donors,providing a novel method for SARS-CoV-2 infected case tracing.
文摘为研究大型机加车间噪声减噪工程现状效果和特点,选取某大型机加车间数控机床为研究对象,对其进行减噪工程治理,现场实测了治理前和治理后的噪声数据,并对噪声测量结果进行分析。研究结果表明:数控机床操作人员8 h连续等效A声级从治理前的89.2 d B(A),降到治理后的74.3 d B(A),降低了16.7%.;数控机床操作岗位位置测点,在加工1个机件的测量时间段里,噪声值从治理前的85.9 d B(A),降到治理后的55.1 d B(A),降低了33.85%;对机加车间现场布置了67个测点,在加工1个机件的测量时间段里进行测量,得到该车间噪声治理前和治理后噪声分布图;对数控机床减噪工程治理前和治理后的频谱进行了分析,得出治理前和治理后各自的最大声级所在频段不随距离的改变而改变,高频减噪效果显著。
文摘By considering mandatory lane-changing as a collision avoidance measure,this paper presented the corresponding lane-change decision making and trajectory planning algorithm under an emergency scenario.Different from the traditional algorithm in which lane-change decision making and trajectory planning are separated,they are here coupled in a proposed algorithm and the related parameters are dynamically adjusted in the whole process.In addition to lane-change collision avoidance feasibility analysis,lanechange time instance and duration time are obtained by solving the constrained convex quadratic optimization programme.By taking lane-change time instance and duration time as inputs,the algorithm then proceeded to propose a kinematic model-based highorder polynomial lane change trajectory.By giving the simulation result compassion with the related algorithm,it is proved that the proposed algorithm has a good robustness and high efficiency.
