Objective:To study the value of the wearable single-lead remote monitoring device with the scatterplot in chronic disease management.Methods:dmitted into 435 residents accord with the inclusion criteria of 20 primary ...Objective:To study the value of the wearable single-lead remote monitoring device with the scatterplot in chronic disease management.Methods:dmitted into 435 residents accord with the inclusion criteria of 20 primary medical institutions of Yinchuan city,and grouped voluntarily by the implementation schemes were grouped voluntarily according to the implementation schemes.According to one of the three implementation schemes selected,the general practitioner guided the subjects to take on the wearable single-lead remote monitoring device,collecting and uploading the EEG data,then diagnosed and analyzed by the synchronously generated ECG scatterplot,finally,summarized the incidence and the categories,analyzed the differences among these three groups.Results:Among 435 subjects,there were 61 normal patients and 374 arrhythmias with the detection rate of 85.98%;and among the 1672 data collected,there were 606 normal data and 1066 arrhythmia with the detection rate of 63.76%;880 data in total 333 cases with atrial premature beat;442 data in total 215 cases with occasional ventricular premature beat;37 data of 22 cases with frequent atrial beat;65 data of 28 cases with frequent ventricular premature beat;13 data of 6 cases with atrial fibrillation;25 data of 15 cases with excitation conduction disorder;2 data of 2 cases with atrial flutter;31 data of 19 cases with ventricular tachycardia;30 data of 16 cases with conduction block;and 14 data of 8 cases with Para systolic rhythm.comparing the detection rate of arrhythmia in three groups,the difference was not statistically significant(P>0.05).Conclusion:The wearable singlelead remote monitoring device with the scatterplot has high application value in cardiovascular chronic disease management.Its effectively screening,validly diagnosing and detailed classifying are helpful to the early intervention,and the protection of the patients’lives.展开更多
Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AO...Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AOC still remains uncertainty.In this study,a comprehensive field campaign was conducted during autumn 2019 in downtown of Beijing,where O_(3) and PM_(2.5) episodes had been experienced successively.The observation-based model(OBM)is used to quantify the AOC at O_(3) and PM_(2.5) episodes.The strong intensity of AOC is found at O_(3) and PM2.5 episodes,and hydroxyl radical(OH)is the dominating daytime oxidant for both episodes.The photolysis of O_(3) is main source of OH at O_(3) episode;the photolysis of nitrous acid(HONO)and formaldehyde(HCHO)plays important role in OH formation at PM_(2.5) episode.The radicals loss routines vary according to precursor pollutants,resulting in different types of air pollution.O_(3) budgets and sensitivity analysis indicates that O_(3) production is transition regime(both VOC and NOx-limited)at O3 episode.The heterogeneous reaction of hydroperoxy radicals(HO_(2))on aerosol surfaces has significant influence on OH and O_(3) production rates.The HO_(2) uptake coefficient(γHO_(2))is the determining factor and required accurate measurement in real atmospheric environment.Our findings could provide the important bases for coordinated control of PM_(2.5) and O_(3) pollution.展开更多
The 4H-SiC crystal is found to have great potential in terahertz generation via nonlinear optical frequency conversion due to its extremely high optical damage threshold,wide transparent range,etc.In this paper,optica...The 4H-SiC crystal is found to have great potential in terahertz generation via nonlinear optical frequency conversion due to its extremely high optical damage threshold,wide transparent range,etc.In this paper,optical rectification(OR)with tilted-pulse-front(TPF)setting based on the 4H-SiC crystal is proposed.The theory accounts for the optimization of incident pulse pre-chirping in the TPF OR process under high-intensity femtosecond laser pumping.Compared with the currently recognized LiNbO3-based TPF OR,which generates a single-cycle terahertz pulse within 3 THz,4HSiC demonstrates a significant advantage in producing ultra-widely tunable(up to over 14 THz,TPF angle 31◦–38◦)terahertz waves with high efficiency(~10–2)and strong field(~MV/cm).Besides,the spectrum characteristics,as well as the evolution from single-to multi-cycle terahertz pulses can be modulated flexibly by pre-chirping.The simulation results show that 4H-SiC enables terahertz frequency extending to an unprecedent range by OR,which has extremely important potential in strong-field terahertz applications.展开更多
The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±1...The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±11.39 ppbv during this period,and alkanes were the major components.There were typical festival effects of NMHCs with lower concentration during the National Day.Alkenes and aromatics were the dominant groups in ozone formation potential(OFP)and OH radical loss rate(L_(OH)).The positive matrix factorization(PMF)running results revealed that vehicular exhaust became the biggest source in urban areas,followed by liquefied petroleum gas(LPG)usage,solvent usage,and fuel evaporation.The box model coupled with master chemical mechanism(MCM)was applied to study the impacts of different NMHCs sources on ozone(O_(3))formation in an O_(3)episode.The simulation results indicated that reducing NMHCs concentration could effectively suppress O_(3)formation.Moreover,reducing traffic-related emissions of NMHCs was an effective way to control O_(3)pollution at an urban site in Beijing.展开更多
As an important precursor of hydroxyl radical(OH),nitrous acid(HONO)plays a significant role in atmospheric chemistry.Here,an observation of HONO and relevant air pollutants in an urban site of Beijing from 14 to 28 A...As an important precursor of hydroxyl radical(OH),nitrous acid(HONO)plays a significant role in atmospheric chemistry.Here,an observation of HONO and relevant air pollutants in an urban site of Beijing from 14 to 28 April,2017 was performed.Two distinct peaks of HONO concentrations occurred during the observation.In contrast,the concentration of particulate matter in the first period(periodⅠ)was significantly higher than that in the second period(periodⅡ).Comparing to HONO sources in the two periods,we found that the direct vehicle emissionwas an essential source of the ambient HONO during both periods at night,especially in periodⅡ.The heterogeneous reaction of NO_(2)was the dominant source in periodⅠ,while the homogeneous reaction of NO with OH was more critical source at night in periodⅡ.In the daytime,the heterogeneous reaction of NO_(2)was a significant source andwas confirmed by the good correlation coefficients(R^(2))between the unknown sources(P_(unknown))with NO_(2),PM_(2.5),NO_(2)×PM_(2.5)in periodⅠ.Moreover,when solar radiation and OH radicals were considered to explore unknown sources in the daytime,the enhanced correlation of P_(unknown)with photolysis rate of NO_(2)and OH(J_(NO_(2))×OH)were 0.93 in periodⅠ,0.95 in periodⅡ.These excellent correlation coefficients suggested that the unknown sources released HONO highly related to the solar radiation and the variation of OH radicals.展开更多
基金The Special Project of Science and technology benefit the people of Ningxia Hui Autonomous Region(2018CMG03015)。
文摘Objective:To study the value of the wearable single-lead remote monitoring device with the scatterplot in chronic disease management.Methods:dmitted into 435 residents accord with the inclusion criteria of 20 primary medical institutions of Yinchuan city,and grouped voluntarily by the implementation schemes were grouped voluntarily according to the implementation schemes.According to one of the three implementation schemes selected,the general practitioner guided the subjects to take on the wearable single-lead remote monitoring device,collecting and uploading the EEG data,then diagnosed and analyzed by the synchronously generated ECG scatterplot,finally,summarized the incidence and the categories,analyzed the differences among these three groups.Results:Among 435 subjects,there were 61 normal patients and 374 arrhythmias with the detection rate of 85.98%;and among the 1672 data collected,there were 606 normal data and 1066 arrhythmia with the detection rate of 63.76%;880 data in total 333 cases with atrial premature beat;442 data in total 215 cases with occasional ventricular premature beat;37 data of 22 cases with frequent atrial beat;65 data of 28 cases with frequent ventricular premature beat;13 data of 6 cases with atrial fibrillation;25 data of 15 cases with excitation conduction disorder;2 data of 2 cases with atrial flutter;31 data of 19 cases with ventricular tachycardia;30 data of 16 cases with conduction block;and 14 data of 8 cases with Para systolic rhythm.comparing the detection rate of arrhythmia in three groups,the difference was not statistically significant(P>0.05).Conclusion:The wearable singlelead remote monitoring device with the scatterplot has high application value in cardiovascular chronic disease management.Its effectively screening,validly diagnosing and detailed classifying are helpful to the early intervention,and the protection of the patients’lives.
基金supported by the National Key Research and Development Program of China (No. 2017YFC0210001)the National Natural Science Foundation of China (Nos. 41830106, 42022039)+1 种基金Beijing National Laboratory for Molecular Sciences (No. BNLMS-CXXM-202011)the Youth Innovation Promotion Association CAS (No. 2017042)
文摘Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AOC still remains uncertainty.In this study,a comprehensive field campaign was conducted during autumn 2019 in downtown of Beijing,where O_(3) and PM_(2.5) episodes had been experienced successively.The observation-based model(OBM)is used to quantify the AOC at O_(3) and PM_(2.5) episodes.The strong intensity of AOC is found at O_(3) and PM2.5 episodes,and hydroxyl radical(OH)is the dominating daytime oxidant for both episodes.The photolysis of O_(3) is main source of OH at O_(3) episode;the photolysis of nitrous acid(HONO)and formaldehyde(HCHO)plays important role in OH formation at PM_(2.5) episode.The radicals loss routines vary according to precursor pollutants,resulting in different types of air pollution.O_(3) budgets and sensitivity analysis indicates that O_(3) production is transition regime(both VOC and NOx-limited)at O3 episode.The heterogeneous reaction of hydroperoxy radicals(HO_(2))on aerosol surfaces has significant influence on OH and O_(3) production rates.The HO_(2) uptake coefficient(γHO_(2))is the determining factor and required accurate measurement in real atmospheric environment.Our findings could provide the important bases for coordinated control of PM_(2.5) and O_(3) pollution.
基金This work was supported by the National Natural Science Foundation of China(No.62175184)the Key Laboratory of Micro Opto-electro Mechanical System Technology,Ministry of Education.
文摘The 4H-SiC crystal is found to have great potential in terahertz generation via nonlinear optical frequency conversion due to its extremely high optical damage threshold,wide transparent range,etc.In this paper,optical rectification(OR)with tilted-pulse-front(TPF)setting based on the 4H-SiC crystal is proposed.The theory accounts for the optimization of incident pulse pre-chirping in the TPF OR process under high-intensity femtosecond laser pumping.Compared with the currently recognized LiNbO3-based TPF OR,which generates a single-cycle terahertz pulse within 3 THz,4HSiC demonstrates a significant advantage in producing ultra-widely tunable(up to over 14 THz,TPF angle 31◦–38◦)terahertz waves with high efficiency(~10–2)and strong field(~MV/cm).Besides,the spectrum characteristics,as well as the evolution from single-to multi-cycle terahertz pulses can be modulated flexibly by pre-chirping.The simulation results show that 4H-SiC enables terahertz frequency extending to an unprecedent range by OR,which has extremely important potential in strong-field terahertz applications.
基金supported by the National Key Research and Development Program of China(No.2017YFC0210001)National Natural Science Foundation of China(Nos.42022039,21671089)+2 种基金the Scientific Research Fund of Liaoning Provincial Education Department(No.L2020002)Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202011)the Youth Innovation Promotion Association CAS(No.2017042)
文摘The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±11.39 ppbv during this period,and alkanes were the major components.There were typical festival effects of NMHCs with lower concentration during the National Day.Alkenes and aromatics were the dominant groups in ozone formation potential(OFP)and OH radical loss rate(L_(OH)).The positive matrix factorization(PMF)running results revealed that vehicular exhaust became the biggest source in urban areas,followed by liquefied petroleum gas(LPG)usage,solvent usage,and fuel evaporation.The box model coupled with master chemical mechanism(MCM)was applied to study the impacts of different NMHCs sources on ozone(O_(3))formation in an O_(3)episode.The simulation results indicated that reducing NMHCs concentration could effectively suppress O_(3)formation.Moreover,reducing traffic-related emissions of NMHCs was an effective way to control O_(3)pollution at an urban site in Beijing.
基金supported by the National Natural Science Foundation of China(Nos.41830106,22006124)Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202011)the Youth Innovation Promotion Association CAS(No.2017042)
文摘As an important precursor of hydroxyl radical(OH),nitrous acid(HONO)plays a significant role in atmospheric chemistry.Here,an observation of HONO and relevant air pollutants in an urban site of Beijing from 14 to 28 April,2017 was performed.Two distinct peaks of HONO concentrations occurred during the observation.In contrast,the concentration of particulate matter in the first period(periodⅠ)was significantly higher than that in the second period(periodⅡ).Comparing to HONO sources in the two periods,we found that the direct vehicle emissionwas an essential source of the ambient HONO during both periods at night,especially in periodⅡ.The heterogeneous reaction of NO_(2)was the dominant source in periodⅠ,while the homogeneous reaction of NO with OH was more critical source at night in periodⅡ.In the daytime,the heterogeneous reaction of NO_(2)was a significant source andwas confirmed by the good correlation coefficients(R^(2))between the unknown sources(P_(unknown))with NO_(2),PM_(2.5),NO_(2)×PM_(2.5)in periodⅠ.Moreover,when solar radiation and OH radicals were considered to explore unknown sources in the daytime,the enhanced correlation of P_(unknown)with photolysis rate of NO_(2)and OH(J_(NO_(2))×OH)were 0.93 in periodⅠ,0.95 in periodⅡ.These excellent correlation coefficients suggested that the unknown sources released HONO highly related to the solar radiation and the variation of OH radicals.