Melioidosis is a zoonotic infectious disease caused by Burkholderia(B.)pseudomallei.It is predominantly endemic in Southeast Asia[1-3].Clinical manifestations are often non-specific,commonly presenting as pneumonia or...Melioidosis is a zoonotic infectious disease caused by Burkholderia(B.)pseudomallei.It is predominantly endemic in Southeast Asia[1-3].Clinical manifestations are often non-specific,commonly presenting as pneumonia or skin abscesses[4],and may progress to severe sepsis with a high case-fatality rate of 10%-50%[5].Due to its early flu-like symptoms,melioidosis is frequently misdiagnosed by clinicians in non-endemic regions.Beijing,located in the North Temperate Zone,rarely reports melioidosis cases;the lack of awareness among healthcare professionals may lead to misdiagnosis and fatal outcomes.展开更多
Systematically analyzing the impact mechanisms of policy on Land Use Conflict(LUC)is crucial for constructing effective conflict mitigation strategies.However,previous research on how policy influences LUC remains rel...Systematically analyzing the impact mechanisms of policy on Land Use Conflict(LUC)is crucial for constructing effective conflict mitigation strategies.However,previous research on how policy influences LUC remains relatively limited.Focusing on the indirect driving role of policy on LUC,this study proposed County Development Level(CDL)under Major Function Oriented Zone Planning(MFOZP)guidance as an intermediary variable,bridging the implicit influence of MFOZP and the explicit changes in LUC.Using the Beijing-Tianjin-Hebei(BTH)region in China as a case study,we analyzed the spatio-temporal evolution characteristics of LUC and CDL for the periods 2000-2010 and 2010-2020,before and after MFOZP implementation.Panel models and Geographically Weighted Regression(GWR)were employed to explore the mechanism by which CDL influences LUC under MFOZP guidance.The results show that:1)MFOZP implementation effectively alleviates land use pressure from regional development,with LUC continuously declining at a rate of 2.41%,while CDL exhibits slight growth(3.84%),during 2010-2020.2)Under MFOZP guidance,CDL reduces pressure on Land Use Structure Conflict(LUSC)and Land Use Process Conflict(LUPC),enhances its inhibitory effect on Land Use Function Conflict(LUFC),and significantly contributes to LUC coordination,with notable spatial heterogeneity.3)The coupling relationship between CDL and LUC has improved post-implementation.Based on this,tailored LUC coordination strategies are proposed for different functional zones.This study confirms the effectiveness of MFOZP in coordinating LUC and provides a scientific reference for LUC research under policy frameworks and the governance of LUC in the BTH region.展开更多
Oil-fired construction machinery(OCM)is a major source of urban air pollutants and CO_(2) emissions,and elec-trification is a crucial pathway for improving air quality and achieving China’s dual carbon goals;however,...Oil-fired construction machinery(OCM)is a major source of urban air pollutants and CO_(2) emissions,and elec-trification is a crucial pathway for improving air quality and achieving China’s dual carbon goals;however,its feasibility has not been fully explored.This study uses data envelopment analysis and the analytic hierarchy process to establish a development potential index,covering technical efficiency,economic cost,application sce-narios,and charging time and range,with an empirical analysis conducted in Beijing.The findings indicated the high feasibility of replacing OCM with electric alternatives,especially within the low-power range.Based on 2023 registered coding dat1,it is projected that by 2030,electrification could reduce regional average con-centrations of CO,NO_(x),PM_(2.5) and VOCs by 12.2%to 56.4%and reduce CO_(2) by 11.7%to 56.9%.Owing to economic considerations,small-and medium-sized machinery are particularly feasible for electrification.Key recommendations include prioritizing the electrification of forklifts,lifting platforms,and small-sized machinery in high-emission areas,particularly in central urban districts.Policies such as carbon taxes,carbon markets,and performance grading systems are suggested to incentivize electrification,along with expanding high-emission restriction zones and improving energy infrastructure to support widespread electrification.展开更多
The rapid urbanization has significantly accelerated the expansion of cities and led to a notable increase in urban land surface temperature(LST).Currently,most studies mainly examine the effects of two-dimensional(2D...The rapid urbanization has significantly accelerated the expansion of cities and led to a notable increase in urban land surface temperature(LST).Currently,most studies mainly examine the effects of two-dimensional(2D)landscape patterns on LST variations,and research investigating the relationship between three-dimensional(3D)urban landscape patterns and LST remains relatively scarce.Therefore,this study utilizes partial correlation analysis and piecewise linear regression to systematically investigate the impacts of gray landscape indicators on LST variations under both 2D and 3D urban patterns,aiming to elucidate the complex relationship between 3D urban landscape patterns and LST dynamics.The results demonstrate that specific 3D building characteristics,particularly the area of low-rise buildings,building aggregation degree,shape complexity,and patch density of mid-rise buildings,serve as effective indicators of urban thermal environment risk.The analysis reveals that increased area-related indicators for low-rise buildings significantly exacerbate the LST rise,whereas modifications to the landscape shape of middle and high-rise buildings contribute to thermal mitigation.Additionally,when gray landscape aggregation exceeds 80%,the spatial concentration of mid-rise buildings exhibits a pronounced positive effect on moderating urban LST.These findings elucidate the mechanisms through which 3D landscape patterns influence urban thermal risks in Beijing,advancing the understanding of urban landscape-ecological processes interactions and providing crucial scientific support for landscape optimization and urban thermal environment risk mitigation strategies.展开更多
This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-fiel...This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.展开更多
Adolescent smoking constitutes a critical public health challenge as early initiation increases the risk of premature mortality and smoking-related chronic diseases due to longer exposure and higher cumulative tobacco...Adolescent smoking constitutes a critical public health challenge as early initiation increases the risk of premature mortality and smoking-related chronic diseases due to longer exposure and higher cumulative tobacco use^([1]).Adolescents are especially prone to developing persistent smoking habits,with many adult smokers having started before the age of 18.In China,16.7%of secondary school students have tried smoking and 4.7%are current smokers,highlighting the critical need for targeted tobacco control interventions among the youth.展开更多
Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and...Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and gridded data)and actual climate data(fixed-point observations near the sampling sites),in northeastern China’s warm temperate zone and analyzed differences in their correlations with tree-ring width index.The results were:(1)Gridded temperature data,as well as precipitation and relative humidity data from the Huailai meteorological station,was more consistent with the actual climate data;in contrast,gridded soil moisture content data showed significant discrepancies.(2)Horizontal distance had a greater impact on the representativeness of actual climate conditions than vertical elevation differences.(3)Differences in consistency between alternative and actual climate data also affected their correlations with tree-ring width indices.In some growing season months,correlation coefficients,both in magnitude and sign,differed significantly from those based on actual data.The selection of different alternative climate datasets can lead to biased results in assessing forest responses to climate change,which is detrimental to the management of forest ecosystems in harsh environments.Therefore,the scientific and rational selection of alternative climate data is essential for dendroecological and climatological research.展开更多
As a key precursor of hydroxyl(OH) radicals, the budget of nitrous acid(HONO) at different altitudes has received extensive attention. In this study, vertically resolved observations of HONO, NO_(2), O_(3), and HCHO w...As a key precursor of hydroxyl(OH) radicals, the budget of nitrous acid(HONO) at different altitudes has received extensive attention. In this study, vertically resolved observations of HONO, NO_(2), O_(3), and HCHO were conducted during an autumn field campaign in Beijing in 2019. The significant correlation between HONO and NO2, along with variations in their ratios across different altitudes, underscores the importance of aerosol surface chemistry in HONO formation and its altitude-dependent behavior. To enhance the model performance, the heterogeneous conversion of NO_(2) and its photochemical enhancement are incorporated into the 1D model. The simulations reveal that the nocturnal HONO production is dominated by the heterogeneous conversion of NO_(2) both at the surface and aloft. During the daytime, groundsurface sources of HONO are mainly driven by nitrate photolysis and light-enhanced heterogeneous conversion of NO_(2).Meanwhile, a large portion of the HONO generated at the surface is transported upwards through vertical mixing. In the higher atmosphere, HONO originates from vertical transport and in situ processes. As precursors of OH radicals, the observed concentrations of HONO, O_(3), and HCHO exhibit distinct diurnal variations and vertical distribution patterns.HONO contributes to OH radical production predominantly during the early morning across all layers and it even becomes the main contributor throughout the daytime in the lowest layer near the ground, while O_(3) and HCHO become more prominent towards midday, especially in the higher layers. These results will be beneficial for a deeper understanding of the atmospheric oxidation process within the urban boundary layer.展开更多
Promoting the deep integration of advanced manufacturing and producer services is not only a key path for metropolitan to climb the global value chain,but also an important new driving force for optimizing urban spati...Promoting the deep integration of advanced manufacturing and producer services is not only a key path for metropolitan to climb the global value chain,but also an important new driving force for optimizing urban spatial structure.Based on the two dimen-sions of industrial linkage and spatial co-agglomeration from the perspective of industrial integration,taking Beijing,China as a case,using industrial input-output data,micro-enterprise spatial data,and methods such as industrial linkage model,standard deviation el-lipse,and spatial similarity coefficient,this study explores the coupling relationship between industrial linkage and spatial co-agglomer-ation of advanced manufacturing and producer services from 2007 to 2020.The results demonstrate that:1)the industrial linkage between advanced manufacturing and producer services in Beijing has an upward trend,in which the business services have the most significant improvement,in which the business services have the most improvement while the technology services have the most de-crease,but in general,the industrial linkage between the two industries shows a low level.2)Producer services were more spatially clustered than advanced manufacturing,and the degree of spatial co-agglomeration of the two also showed an increasing trend,with strong regional and industrial heterogeneity characteristics,among which the pairing industry involving commerce services and techno-logy services had a more obvious improvement.3)The coupling analysis found that the spatial dependence between advanced manufac-turing and producer services decreased,showing a weak positive correlation and a decreasing trend between industrial linkage and spa-tial co-agglomeration;the heterogeneity among subdivision pairs is prominent,and the strong correlation between industries does not mean that there is an inevitable spatial co-agglomeration.4)Based on the differences in coupling relationships and influence mechan-isms,four coupling modes are identified:H-H type,H-L type,L-L type,and L-H type.Finally,this study proposes three policy implica-tions for the integration of advanced manufacturing and producer services in metropolitan areas.展开更多
Respiratory infections are associated with high morbidity and mortality and are a major global health problem[1].Acute respiratory infections are caused by multiple respiratory pathogens,including viruses and bacteria...Respiratory infections are associated with high morbidity and mortality and are a major global health problem[1].Acute respiratory infections are caused by multiple respiratory pathogens,including viruses and bacteria.Viral-bacterial co-infections,which have become increasingly common and a global concern,can lead to substantial complications,causing higher morbidity and adverse prognosis[2].Previous studies have reported low positive detection rates of targeted pathogens related to acute respiratory infections,owing to the limited number of detected pathogens and variations in the sensitivity of diagnostic methods[3-4].Low positive detection rates may impede our understanding of respiratory pathogen characteristics and hamper the development of precise treatment and prevention strategies.展开更多
Couplets,as a vital symbol of Chinese traditional culture,hold prominent cultural significance in Beijing’s urban neighborhoods.This paper assesses the current state of cultural communication efficacy regarding coupl...Couplets,as a vital symbol of Chinese traditional culture,hold prominent cultural significance in Beijing’s urban neighborhoods.This paper assesses the current state of cultural communication efficacy regarding couplets in Beijing’s neighborhoods,identifying challenges including fragile cultural ecosystems,limitations of communication agents,homogeneity in content and forms,and outdated dissemination mechanisms.To address these issues,the study conducts an in-depth analysis of strategies to enhance the cultural dissemination capacity of Beijing’s neighborhood couplet culture,proposing comprehensive enhancement pathways.The research aims to effectively elevate the cultural influence of Beijing’s neighborhood couplet culture and facilitate the city’s development as a national cultural center.展开更多
The Beijing-Tianjin-Hebei Plain is among the regions in China that feature the largest scale and the fastest growth in medium and deep geothermal heating.Based on tests of 82 geothermal fluid samples from 7 geothermal...The Beijing-Tianjin-Hebei Plain is among the regions in China that feature the largest scale and the fastest growth in medium and deep geothermal heating.Based on tests of 82 geothermal fluid samples from 7 geothermal fields in Hebei Province,2 geothermal fields in Henan Province,and 2 geothermal fields in Shandong Province,and combined with previous studies on the chemical characteristics of karst geothermal water in Beijing and Tianjin,this paper systematically analyzes the migration characteristics of geothermal fluids in karst geothermal reservoirs within the Beijing-Tianjin-Hebei Plain.The hydrochemical characteristics of karst geothermal water in the research areas exhibit certain differences.The geothermal water in Hebei is more mature than that in its neighboring provinces.The distribution of total dissolved solids(TDS)and strontium elements in the area is characterized by being low in the north and south and high in the middle,suggesting that the overall flow direction of geothermal fluid is from the north and south towards the middle.Combined with the groundwater flow field and the changing trend of the hydrochemical characteristics of geothermal wells along the geological section,a geothermal water migration model has been established.The geothermal fluids originating from Taihang Mountain,Yanshan Mountain,and Western Shandong Mountain enter the basin and continue to migrate towards the central part of the basin along water-conducting faults.However,the migration characteristics of geothermal fluids with the same supply direction are not identical.The geothermal fluids from Taihang Mountain are cut off by the Niudong Fault in the north and terminate in the central uplift belt of the Jizhong Depression,while in the south,they enter the east of the Jizhong Depression relatively quickly along the Hengshui Conversion Belt.The geothermal fluids from Yanshan Mountain migrate into the basin along the Cangdong Fault,yet this fault also disrupts the hydraulic connection between the tectonic units.Considering the effective dynamic conditions,it is recommended to further expand the scale of the scientific development and utilization of geothermal energy in the geothermal water catchment areas around Xiongxian County and southwest Cangzhou City.展开更多
In the context of global climate change,the increasing frequency of extreme weather events presents significant challenges to urban water systems.This study focuses on the Beijing section of the Beijing-Hangzhou Grand...In the context of global climate change,the increasing frequency of extreme weather events presents significant challenges to urban water systems.This study focuses on the Beijing section of the Beijing-Hangzhou Grand Canal,introduces the SEE model,and develops an integrated“comprehensive water environment simulation model”to systematically examine the path for enhancing its climate resilience.Through the coupling of multiple models(MIKE 11,MIKE URBAN,MIKE 21)and scenario simulations,this study analyzes the response mechanisms of various governance strategies under extreme climate conditions.The research proposes four specific measures to enhance resilience:dual-scenario simulation of climate and governance,identification and reinforcement of weak points in resilience,parametric modeling of ecological restoration interventions,and the development of a“digital twin canal system”.The research findings indicate that the system integration of the SEE model substantially improves the adaptability,endurance,and recovery capacity of canals in response to climate shocks,including heavy rainfall and drought.This provides a scientific foundation and a practical path for achieving long-term resilience and sustainable development of urban water systems.展开更多
The construction of“park cities”requires a systematic thinking to coordinate the networked development of park system and break through the limitation of emphasizing scale and grade and neglecting dynamic correlatio...The construction of“park cities”requires a systematic thinking to coordinate the networked development of park system and break through the limitation of emphasizing scale and grade and neglecting dynamic correlation in traditional planning.Taking Haidian District of Beijing as an example,the social network analysis method is introduced to construct the network model of park green spaces.Through indicators such as clustering coefficient,network density and node centrality,the characteristics of its spatial structure and hierarchical relationship are analyzed.It is found that the network integrity presents the characteristics of“highly local concentration and global fragmentation”,fragmented park green space network and missing spatial connection,isolated clusters and collaborative failure,as well as the spatial mismatch between population and resource supply and demand.Hierarchical issues include“structural imbalance and functional disorder”,disorder between network hierarchy and park level,misalignment of functional hierarchy leading to weakened network risk resistance capacity,and a relatively dense distribution of core nodes,etc.In response to the above problems,a multi-level spatial intervention strategy should be adopted to solve the overall problem of the network.Meanwhile,it is needed to clarify the positioning of a park itself and improve the hierarchical system,so as to construct a multi-level and multi-scale park green space network,contribute to the construction of a park city,and provide residents with more diverse activity venues.展开更多
In recent years,incidents of simultaneous exceedance of PM_(2.5)and O_(3) concentrations,termed PM_(2.5)and O_(3) co-pollution events,have frequently occurred in China.This study conducted atmospheric circulation anal...In recent years,incidents of simultaneous exceedance of PM_(2.5)and O_(3) concentrations,termed PM_(2.5)and O_(3) co-pollution events,have frequently occurred in China.This study conducted atmospheric circulation analysis on two typical co-pollution events in Beijing,occurring from July 22 to July 28,2019,and from April 25 to May 2,2020.These events were categorized into pre-trough southerly airflow type(Type 1)and post-trough northwest flow type(Type 2).Subsequently,sensitivity analyses using the GRAPES-CUACE adjoint model were performed to quantify the contributions of precursor emissions from Beijing and surrounding areas to PM_(2.5)and O_(3) concentrations in Beijing for two types of co-pollution.The results indicated that the spatiotemporal distribution of sensitive source region varied among different circulation types.Primary PM_(2.5)(PPM_(2.5))emissions from Hebei contributed the most to the 24-hour average PM_(2.5)(24-h PM_(2.5))peak concentration(41.6%-45.4%),followed by Beijing emissions(31%-35.7%).The maximum daily 8-hour average ozone peak concentration was primarily influenced by the emissions from Hebei and Beijing,with contribution ratios respectively of 32.8%-44.8% and 29%-42.1%.Additionally,NO_(x)emissions were the main contributors in Type 1,while both NO_(x)and VOCs emissions contributed similarly in Type 2.The iterative emission reduction experiments for two types of co-pollution indicated that Type 1 required emission reductions in NO_(x)(52.4%-71.8%)and VOCs(14.1%-33.8%)only.In contrast,Type 2 required combined emission reductions in NO_(x)(37.0%-65.1%),VOCs(30.7%-56.2%),and PPM_(2.5)(31%-46.9%).This study provided a reference for controlling co-pollution events and improving air quality in Beijing.展开更多
A novel digital twin(DT)enabled channel model for 6G vehicular communications in Beijing Central Business District(Beijing CBD)is proposed,which can support the design of intelligent transportation systems(ITSs).A DT ...A novel digital twin(DT)enabled channel model for 6G vehicular communications in Beijing Central Business District(Beijing CBD)is proposed,which can support the design of intelligent transportation systems(ITSs).A DT space for Beijing CBD is constructed,and two typical transportation periods,i.e.,peak and off-peak hours,are considered to characterize the vehicular communication channel better.Based on the constructed DT space,a DT-enabled vehicular communication dataset is developed,including light detection and ranging(LiDAR)point clouds,RGB images,and channel information.With the assistance of LiDAR point clouds and RGB images,the scatterer parameters,including number,distance,angle,power,and velocity,are analyzed under different transportation periods.The channel non-stationarity and consistency are mimicked in the proposed model.The key channel statistical properties are derived and simulated.Compared to ray-tracing(RT)results,the accuracy of the proposed model is verified.展开更多
To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission leve...To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration method.We investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the future.The results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance rate.Differenceswere observed amongmachinery types,with low-power engine forklifts showing higher smoke levels.The NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively small.Engine rated net power had the most significant impact on NO_(x)emissions.Thus,NO_(x)emissions from construction machinery need further attention.Furthermore,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission limits.In the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.展开更多
Although air pollutant emissions have sharply reduced in recent years,the occurrence of PM_(2.5) pollution events remains an intractable environmental problem in Beijing,and regional transport is the key influence fac...Although air pollutant emissions have sharply reduced in recent years,the occurrence of PM_(2.5) pollution events remains an intractable environmental problem in Beijing,and regional transport is the key influence factor.However,it has been difficult to identify regional transport characteristics and the main contributors to pollution events in recent years.In this study,the relative contribution of regional transport was quantified(61.3%)in PM_(2.5) pollution events during 2018-2021 by the Community Multiscale Air Quality model embedded with the Integrated Source Apportionment Model(CMAQ-ISAM).The four regions with the largest fractional contributions to Beijing for all events were Shandong(7.7%),South Hebei(7.3%),Baoding(6.2%),and Langfang(5.8%).Pollution events were classified into the following types based on regional transport directions:local,southwest(SW),southeast(SE),south-mixed(SM),and others.Based on the transport distance,the SW,SE,and SM types can be subdivided into SW-short,SW-long,SE-short,SE-long,SM-short,SM-long distance from southwest,SM-long distance from southeast,and SM-long distance from southwest and southeast.SE-long was regarded as the most important type,with the highest relative frequency(20%).The transport directions were related to the southwest wind at 925 hPa and southeast wind at 1000 hPa in the south of the Beijing–Tianjin–Hebei(BTH)region,and the distance was mainly controlled by wind strength.The wind-field difference can be attributed to the low-pressure and high-pressure systems that control the BTH region.The results suggest that regional joint pollution control should be optimized based on the transport type.展开更多
Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess...Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess the dietary quality of postpartum women in urban Beijing,identify occupational-related factors influencing their diet,and explore potential interventions to improve maternal nutrition during the postpartum period.Methods:In this cross-sectional analysis,554 women one year after delivery were recruited from ten community health centers.Sociodemographic,occupational and postpartum care variables were collected via questionnaire.Dietary intake over the preceding year was assessed using a food frequency questionnaire.The modified dietary balance index for postpartum women were used for dietary quality assessment.Results:The study revealed severe dietary imbalances among postpartum women,characterized by excessive consumption of cereals,eggs,and meats,while their intake of vegetables,fruits,and dairy products was inadequate.According to dietary balance index for postpartum women,66.25%of mothers showed varying degrees of excessive intake.45.31%of mothers experienced varying levels of insufficient intake,with only 19.86%of participants having a relatively balanced diet.Occupational differences were observed,with women in the commercial employment group showing higher levels of excessive food intake.The analysis of influencing factors showed that family monthly income,maternity leave,and postpartum care significantly affected the dietary quality.Conclusions:Postpartum women in Beijing experience widespread dietary imbalances,with both excesses and deficiencies.Occupational context and related factors significantly shape diet quality.These findings highlight the need for targeted nutritional interventions tailored to the specific challenges of different occupational groups.展开更多
基金supported by the Capital’s Funds for Health Improvement and Research(2024-1G-4362)the National Key Program for Infectious Disease of China(2018ZX10714002-003-002).
文摘Melioidosis is a zoonotic infectious disease caused by Burkholderia(B.)pseudomallei.It is predominantly endemic in Southeast Asia[1-3].Clinical manifestations are often non-specific,commonly presenting as pneumonia or skin abscesses[4],and may progress to severe sepsis with a high case-fatality rate of 10%-50%[5].Due to its early flu-like symptoms,melioidosis is frequently misdiagnosed by clinicians in non-endemic regions.Beijing,located in the North Temperate Zone,rarely reports melioidosis cases;the lack of awareness among healthcare professionals may lead to misdiagnosis and fatal outcomes.
基金Under the auspices of the National Key Research and Development Program of China(No.2018YFD1100803)the Fundamental Research Fund for the Central Universities(Ph.D.Top Innovative Talents Fund of CUMTB)(No.BBJ2024029)。
文摘Systematically analyzing the impact mechanisms of policy on Land Use Conflict(LUC)is crucial for constructing effective conflict mitigation strategies.However,previous research on how policy influences LUC remains relatively limited.Focusing on the indirect driving role of policy on LUC,this study proposed County Development Level(CDL)under Major Function Oriented Zone Planning(MFOZP)guidance as an intermediary variable,bridging the implicit influence of MFOZP and the explicit changes in LUC.Using the Beijing-Tianjin-Hebei(BTH)region in China as a case study,we analyzed the spatio-temporal evolution characteristics of LUC and CDL for the periods 2000-2010 and 2010-2020,before and after MFOZP implementation.Panel models and Geographically Weighted Regression(GWR)were employed to explore the mechanism by which CDL influences LUC under MFOZP guidance.The results show that:1)MFOZP implementation effectively alleviates land use pressure from regional development,with LUC continuously declining at a rate of 2.41%,while CDL exhibits slight growth(3.84%),during 2010-2020.2)Under MFOZP guidance,CDL reduces pressure on Land Use Structure Conflict(LUSC)and Land Use Process Conflict(LUPC),enhances its inhibitory effect on Land Use Function Conflict(LUFC),and significantly contributes to LUC coordination,with notable spatial heterogeneity.3)The coupling relationship between CDL and LUC has improved post-implementation.Based on this,tailored LUC coordination strategies are proposed for different functional zones.This study confirms the effectiveness of MFOZP in coordinating LUC and provides a scientific reference for LUC research under policy frameworks and the governance of LUC in the BTH region.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2024ZD1200200).
文摘Oil-fired construction machinery(OCM)is a major source of urban air pollutants and CO_(2) emissions,and elec-trification is a crucial pathway for improving air quality and achieving China’s dual carbon goals;however,its feasibility has not been fully explored.This study uses data envelopment analysis and the analytic hierarchy process to establish a development potential index,covering technical efficiency,economic cost,application sce-narios,and charging time and range,with an empirical analysis conducted in Beijing.The findings indicated the high feasibility of replacing OCM with electric alternatives,especially within the low-power range.Based on 2023 registered coding dat1,it is projected that by 2030,electrification could reduce regional average con-centrations of CO,NO_(x),PM_(2.5) and VOCs by 12.2%to 56.4%and reduce CO_(2) by 11.7%to 56.9%.Owing to economic considerations,small-and medium-sized machinery are particularly feasible for electrification.Key recommendations include prioritizing the electrification of forklifts,lifting platforms,and small-sized machinery in high-emission areas,particularly in central urban districts.Policies such as carbon taxes,carbon markets,and performance grading systems are suggested to incentivize electrification,along with expanding high-emission restriction zones and improving energy infrastructure to support widespread electrification.
基金supported by the National Key Research and Development Program of China[grant number 2024YFF1306200]the National Natural Science Foundation of China[grant number 42171318].
文摘The rapid urbanization has significantly accelerated the expansion of cities and led to a notable increase in urban land surface temperature(LST).Currently,most studies mainly examine the effects of two-dimensional(2D)landscape patterns on LST variations,and research investigating the relationship between three-dimensional(3D)urban landscape patterns and LST remains relatively scarce.Therefore,this study utilizes partial correlation analysis and piecewise linear regression to systematically investigate the impacts of gray landscape indicators on LST variations under both 2D and 3D urban patterns,aiming to elucidate the complex relationship between 3D urban landscape patterns and LST dynamics.The results demonstrate that specific 3D building characteristics,particularly the area of low-rise buildings,building aggregation degree,shape complexity,and patch density of mid-rise buildings,serve as effective indicators of urban thermal environment risk.The analysis reveals that increased area-related indicators for low-rise buildings significantly exacerbate the LST rise,whereas modifications to the landscape shape of middle and high-rise buildings contribute to thermal mitigation.Additionally,when gray landscape aggregation exceeds 80%,the spatial concentration of mid-rise buildings exhibits a pronounced positive effect on moderating urban LST.These findings elucidate the mechanisms through which 3D landscape patterns influence urban thermal risks in Beijing,advancing the understanding of urban landscape-ecological processes interactions and providing crucial scientific support for landscape optimization and urban thermal environment risk mitigation strategies.
基金supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(Grant No.2025ZD005100)by Beijing Geolight Technology Co.,Ltd.under the project“The Impact of Strong Ground Motion on Buildings”(YF-202520).
文摘This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.
基金supported by the World Health Organization Global Youth Tobacco Survey(WPDHP1206671)the Global Health Capacity Building and Tobacco Control Project:Tobacco Epidemic Monitoring and Comprehensive Tobacco Control Intervention。
文摘Adolescent smoking constitutes a critical public health challenge as early initiation increases the risk of premature mortality and smoking-related chronic diseases due to longer exposure and higher cumulative tobacco use^([1]).Adolescents are especially prone to developing persistent smoking habits,with many adult smokers having started before the age of 18.In China,16.7%of secondary school students have tried smoking and 4.7%are current smokers,highlighting the critical need for targeted tobacco control interventions among the youth.
基金supported by the International Partnership program of the Chinese Academy of Sciences(170GJHZ2023074GC)National Natural Science Foundation of China(42425706 and 42488201)+1 种基金National Key Research and Development Program of China(2024YFF0807902)Beijing Natural Science Foundation(8242041),and China Postdoctoral Science Foundation(2025M770353).
文摘Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and gridded data)and actual climate data(fixed-point observations near the sampling sites),in northeastern China’s warm temperate zone and analyzed differences in their correlations with tree-ring width index.The results were:(1)Gridded temperature data,as well as precipitation and relative humidity data from the Huailai meteorological station,was more consistent with the actual climate data;in contrast,gridded soil moisture content data showed significant discrepancies.(2)Horizontal distance had a greater impact on the representativeness of actual climate conditions than vertical elevation differences.(3)Differences in consistency between alternative and actual climate data also affected their correlations with tree-ring width indices.In some growing season months,correlation coefficients,both in magnitude and sign,differed significantly from those based on actual data.The selection of different alternative climate datasets can lead to biased results in assessing forest responses to climate change,which is detrimental to the management of forest ecosystems in harsh environments.Therefore,the scientific and rational selection of alternative climate data is essential for dendroecological and climatological research.
基金supported by the National Natural Science Foundation of China (Grant Nos.42075097,42177081 and 22176037)。
文摘As a key precursor of hydroxyl(OH) radicals, the budget of nitrous acid(HONO) at different altitudes has received extensive attention. In this study, vertically resolved observations of HONO, NO_(2), O_(3), and HCHO were conducted during an autumn field campaign in Beijing in 2019. The significant correlation between HONO and NO2, along with variations in their ratios across different altitudes, underscores the importance of aerosol surface chemistry in HONO formation and its altitude-dependent behavior. To enhance the model performance, the heterogeneous conversion of NO_(2) and its photochemical enhancement are incorporated into the 1D model. The simulations reveal that the nocturnal HONO production is dominated by the heterogeneous conversion of NO_(2) both at the surface and aloft. During the daytime, groundsurface sources of HONO are mainly driven by nitrate photolysis and light-enhanced heterogeneous conversion of NO_(2).Meanwhile, a large portion of the HONO generated at the surface is transported upwards through vertical mixing. In the higher atmosphere, HONO originates from vertical transport and in situ processes. As precursors of OH radicals, the observed concentrations of HONO, O_(3), and HCHO exhibit distinct diurnal variations and vertical distribution patterns.HONO contributes to OH radical production predominantly during the early morning across all layers and it even becomes the main contributor throughout the daytime in the lowest layer near the ground, while O_(3) and HCHO become more prominent towards midday, especially in the higher layers. These results will be beneficial for a deeper understanding of the atmospheric oxidation process within the urban boundary layer.
基金Under the auspices of National Natural Science Foundation of China(No.42371181)。
文摘Promoting the deep integration of advanced manufacturing and producer services is not only a key path for metropolitan to climb the global value chain,but also an important new driving force for optimizing urban spatial structure.Based on the two dimen-sions of industrial linkage and spatial co-agglomeration from the perspective of industrial integration,taking Beijing,China as a case,using industrial input-output data,micro-enterprise spatial data,and methods such as industrial linkage model,standard deviation el-lipse,and spatial similarity coefficient,this study explores the coupling relationship between industrial linkage and spatial co-agglomer-ation of advanced manufacturing and producer services from 2007 to 2020.The results demonstrate that:1)the industrial linkage between advanced manufacturing and producer services in Beijing has an upward trend,in which the business services have the most significant improvement,in which the business services have the most improvement while the technology services have the most de-crease,but in general,the industrial linkage between the two industries shows a low level.2)Producer services were more spatially clustered than advanced manufacturing,and the degree of spatial co-agglomeration of the two also showed an increasing trend,with strong regional and industrial heterogeneity characteristics,among which the pairing industry involving commerce services and techno-logy services had a more obvious improvement.3)The coupling analysis found that the spatial dependence between advanced manufac-turing and producer services decreased,showing a weak positive correlation and a decreasing trend between industrial linkage and spa-tial co-agglomeration;the heterogeneity among subdivision pairs is prominent,and the strong correlation between industries does not mean that there is an inevitable spatial co-agglomeration.4)Based on the differences in coupling relationships and influence mechan-isms,four coupling modes are identified:H-H type,H-L type,L-L type,and L-H type.Finally,this study proposes three policy implica-tions for the integration of advanced manufacturing and producer services in metropolitan areas.
基金supported by the Beijing Science and Technology Planning Project of the Beijing Science and Technology Commission(Z241100009024047)the High-Level Public Health Technical Talent Training Plan(lingjunrencai-01-02).
文摘Respiratory infections are associated with high morbidity and mortality and are a major global health problem[1].Acute respiratory infections are caused by multiple respiratory pathogens,including viruses and bacteria.Viral-bacterial co-infections,which have become increasingly common and a global concern,can lead to substantial complications,causing higher morbidity and adverse prognosis[2].Previous studies have reported low positive detection rates of targeted pathogens related to acute respiratory infections,owing to the limited number of detected pathogens and variations in the sensitivity of diagnostic methods[3-4].Low positive detection rates may impede our understanding of respiratory pathogen characteristics and hamper the development of precise treatment and prevention strategies.
文摘Couplets,as a vital symbol of Chinese traditional culture,hold prominent cultural significance in Beijing’s urban neighborhoods.This paper assesses the current state of cultural communication efficacy regarding couplets in Beijing’s neighborhoods,identifying challenges including fragile cultural ecosystems,limitations of communication agents,homogeneity in content and forms,and outdated dissemination mechanisms.To address these issues,the study conducts an in-depth analysis of strategies to enhance the cultural dissemination capacity of Beijing’s neighborhood couplet culture,proposing comprehensive enhancement pathways.The research aims to effectively elevate the cultural influence of Beijing’s neighborhood couplet culture and facilitate the city’s development as a national cultural center.
基金support received from the National Major Special Project titled“Exploration and Evaluation of Deep Geothermal Energy in Key Regions”(Project No.2024ZD1003600)the Science and Technology Department of Sinopec(Project No.JP24071).
文摘The Beijing-Tianjin-Hebei Plain is among the regions in China that feature the largest scale and the fastest growth in medium and deep geothermal heating.Based on tests of 82 geothermal fluid samples from 7 geothermal fields in Hebei Province,2 geothermal fields in Henan Province,and 2 geothermal fields in Shandong Province,and combined with previous studies on the chemical characteristics of karst geothermal water in Beijing and Tianjin,this paper systematically analyzes the migration characteristics of geothermal fluids in karst geothermal reservoirs within the Beijing-Tianjin-Hebei Plain.The hydrochemical characteristics of karst geothermal water in the research areas exhibit certain differences.The geothermal water in Hebei is more mature than that in its neighboring provinces.The distribution of total dissolved solids(TDS)and strontium elements in the area is characterized by being low in the north and south and high in the middle,suggesting that the overall flow direction of geothermal fluid is from the north and south towards the middle.Combined with the groundwater flow field and the changing trend of the hydrochemical characteristics of geothermal wells along the geological section,a geothermal water migration model has been established.The geothermal fluids originating from Taihang Mountain,Yanshan Mountain,and Western Shandong Mountain enter the basin and continue to migrate towards the central part of the basin along water-conducting faults.However,the migration characteristics of geothermal fluids with the same supply direction are not identical.The geothermal fluids from Taihang Mountain are cut off by the Niudong Fault in the north and terminate in the central uplift belt of the Jizhong Depression,while in the south,they enter the east of the Jizhong Depression relatively quickly along the Hengshui Conversion Belt.The geothermal fluids from Yanshan Mountain migrate into the basin along the Cangdong Fault,yet this fault also disrupts the hydraulic connection between the tectonic units.Considering the effective dynamic conditions,it is recommended to further expand the scale of the scientific development and utilization of geothermal energy in the geothermal water catchment areas around Xiongxian County and southwest Cangzhou City.
基金Sponsored by 2025 Postgraduate Teaching Reform Project of North China University of Technology。
文摘In the context of global climate change,the increasing frequency of extreme weather events presents significant challenges to urban water systems.This study focuses on the Beijing section of the Beijing-Hangzhou Grand Canal,introduces the SEE model,and develops an integrated“comprehensive water environment simulation model”to systematically examine the path for enhancing its climate resilience.Through the coupling of multiple models(MIKE 11,MIKE URBAN,MIKE 21)and scenario simulations,this study analyzes the response mechanisms of various governance strategies under extreme climate conditions.The research proposes four specific measures to enhance resilience:dual-scenario simulation of climate and governance,identification and reinforcement of weak points in resilience,parametric modeling of ecological restoration interventions,and the development of a“digital twin canal system”.The research findings indicate that the system integration of the SEE model substantially improves the adaptability,endurance,and recovery capacity of canals in response to climate shocks,including heavy rainfall and drought.This provides a scientific foundation and a practical path for achieving long-term resilience and sustainable development of urban water systems.
文摘The construction of“park cities”requires a systematic thinking to coordinate the networked development of park system and break through the limitation of emphasizing scale and grade and neglecting dynamic correlation in traditional planning.Taking Haidian District of Beijing as an example,the social network analysis method is introduced to construct the network model of park green spaces.Through indicators such as clustering coefficient,network density and node centrality,the characteristics of its spatial structure and hierarchical relationship are analyzed.It is found that the network integrity presents the characteristics of“highly local concentration and global fragmentation”,fragmented park green space network and missing spatial connection,isolated clusters and collaborative failure,as well as the spatial mismatch between population and resource supply and demand.Hierarchical issues include“structural imbalance and functional disorder”,disorder between network hierarchy and park level,misalignment of functional hierarchy leading to weakened network risk resistance capacity,and a relatively dense distribution of core nodes,etc.In response to the above problems,a multi-level spatial intervention strategy should be adopted to solve the overall problem of the network.Meanwhile,it is needed to clarify the positioning of a park itself and improve the hierarchical system,so as to construct a multi-level and multi-scale park green space network,contribute to the construction of a park city,and provide residents with more diverse activity venues.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701205)the National Natural Science Foundation of China(No.41975173)the Science and Technology Development Fund of the Chinese Academy of Meteorological Sciences(No.2021KJ011)。
文摘In recent years,incidents of simultaneous exceedance of PM_(2.5)and O_(3) concentrations,termed PM_(2.5)and O_(3) co-pollution events,have frequently occurred in China.This study conducted atmospheric circulation analysis on two typical co-pollution events in Beijing,occurring from July 22 to July 28,2019,and from April 25 to May 2,2020.These events were categorized into pre-trough southerly airflow type(Type 1)and post-trough northwest flow type(Type 2).Subsequently,sensitivity analyses using the GRAPES-CUACE adjoint model were performed to quantify the contributions of precursor emissions from Beijing and surrounding areas to PM_(2.5)and O_(3) concentrations in Beijing for two types of co-pollution.The results indicated that the spatiotemporal distribution of sensitive source region varied among different circulation types.Primary PM_(2.5)(PPM_(2.5))emissions from Hebei contributed the most to the 24-hour average PM_(2.5)(24-h PM_(2.5))peak concentration(41.6%-45.4%),followed by Beijing emissions(31%-35.7%).The maximum daily 8-hour average ozone peak concentration was primarily influenced by the emissions from Hebei and Beijing,with contribution ratios respectively of 32.8%-44.8% and 29%-42.1%.Additionally,NO_(x)emissions were the main contributors in Type 1,while both NO_(x)and VOCs emissions contributed similarly in Type 2.The iterative emission reduction experiments for two types of co-pollution indicated that Type 1 required emission reductions in NO_(x)(52.4%-71.8%)and VOCs(14.1%-33.8%)only.In contrast,Type 2 required combined emission reductions in NO_(x)(37.0%-65.1%),VOCs(30.7%-56.2%),and PPM_(2.5)(31%-46.9%).This study provided a reference for controlling co-pollution events and improving air quality in Beijing.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.62371273,62125101 and 62341101the Taishan Scholars Program under Grant No.tsqn202312307+7 种基金the Young Elite Scientists Sponsorship Program by CAST under Grant No.YESS20230372the Shandong Natural Science Foundation under Grant No.ZR2023YQ058the New Cornerstone Science Foundation through the Xplorer Prizethe Xiaomi Young Talents Programthe open research fund of National Mobile Communications Research Laboratory,Southeast University under Grant No.2025D04the China National Postdoctoral Program for Innovative Talents under Grant No.BX20240007the China Postdoctoral Science Foundation under Grant No.2024M760111the Beijing Natural Science Foundation under Grant No.4254067。
文摘A novel digital twin(DT)enabled channel model for 6G vehicular communications in Beijing Central Business District(Beijing CBD)is proposed,which can support the design of intelligent transportation systems(ITSs).A DT space for Beijing CBD is constructed,and two typical transportation periods,i.e.,peak and off-peak hours,are considered to characterize the vehicular communication channel better.Based on the constructed DT space,a DT-enabled vehicular communication dataset is developed,including light detection and ranging(LiDAR)point clouds,RGB images,and channel information.With the assistance of LiDAR point clouds and RGB images,the scatterer parameters,including number,distance,angle,power,and velocity,are analyzed under different transportation periods.The channel non-stationarity and consistency are mimicked in the proposed model.The key channel statistical properties are derived and simulated.Compared to ray-tracing(RT)results,the accuracy of the proposed model is verified.
基金supported by the Energy Foundation(No.G-2203-33693).
文摘To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration method.We investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the future.The results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance rate.Differenceswere observed amongmachinery types,with low-power engine forklifts showing higher smoke levels.The NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively small.Engine rated net power had the most significant impact on NO_(x)emissions.Thus,NO_(x)emissions from construction machinery need further attention.Furthermore,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission limits.In the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.
基金supported by the National Key R&D program of China(No.2022YFC3703404)the National Natural Science Foundation of China(No.22188102)the Samsung Advanced Institute of Technology.
文摘Although air pollutant emissions have sharply reduced in recent years,the occurrence of PM_(2.5) pollution events remains an intractable environmental problem in Beijing,and regional transport is the key influence factor.However,it has been difficult to identify regional transport characteristics and the main contributors to pollution events in recent years.In this study,the relative contribution of regional transport was quantified(61.3%)in PM_(2.5) pollution events during 2018-2021 by the Community Multiscale Air Quality model embedded with the Integrated Source Apportionment Model(CMAQ-ISAM).The four regions with the largest fractional contributions to Beijing for all events were Shandong(7.7%),South Hebei(7.3%),Baoding(6.2%),and Langfang(5.8%).Pollution events were classified into the following types based on regional transport directions:local,southwest(SW),southeast(SE),south-mixed(SM),and others.Based on the transport distance,the SW,SE,and SM types can be subdivided into SW-short,SW-long,SE-short,SE-long,SM-short,SM-long distance from southwest,SM-long distance from southeast,and SM-long distance from southwest and southeast.SE-long was regarded as the most important type,with the highest relative frequency(20%).The transport directions were related to the southwest wind at 925 hPa and southeast wind at 1000 hPa in the south of the Beijing–Tianjin–Hebei(BTH)region,and the distance was mainly controlled by wind strength.The wind-field difference can be attributed to the low-pressure and high-pressure systems that control the BTH region.The results suggest that regional joint pollution control should be optimized based on the transport type.
基金supported by an Innovation Fund for Medical Sciences of the Chinese Academy of Medical Sciences (Grant No.2019-I2M-2-007).
文摘Objective:Postpartum nutrition plays a critical role in maternal recovery and long-term health.However,the nutritional status of working mothers in the postpartum period remains understudied.This study aimed to assess the dietary quality of postpartum women in urban Beijing,identify occupational-related factors influencing their diet,and explore potential interventions to improve maternal nutrition during the postpartum period.Methods:In this cross-sectional analysis,554 women one year after delivery were recruited from ten community health centers.Sociodemographic,occupational and postpartum care variables were collected via questionnaire.Dietary intake over the preceding year was assessed using a food frequency questionnaire.The modified dietary balance index for postpartum women were used for dietary quality assessment.Results:The study revealed severe dietary imbalances among postpartum women,characterized by excessive consumption of cereals,eggs,and meats,while their intake of vegetables,fruits,and dairy products was inadequate.According to dietary balance index for postpartum women,66.25%of mothers showed varying degrees of excessive intake.45.31%of mothers experienced varying levels of insufficient intake,with only 19.86%of participants having a relatively balanced diet.Occupational differences were observed,with women in the commercial employment group showing higher levels of excessive food intake.The analysis of influencing factors showed that family monthly income,maternity leave,and postpartum care significantly affected the dietary quality.Conclusions:Postpartum women in Beijing experience widespread dietary imbalances,with both excesses and deficiencies.Occupational context and related factors significantly shape diet quality.These findings highlight the need for targeted nutritional interventions tailored to the specific challenges of different occupational groups.
