Objective This study aimed to investigate the impact of glycemic control and diabetes duration on subsequent myocardial infarction(MI)in patients with both coronary heart disease(CHD)and type 2 diabetes(T2D).Methods W...Objective This study aimed to investigate the impact of glycemic control and diabetes duration on subsequent myocardial infarction(MI)in patients with both coronary heart disease(CHD)and type 2 diabetes(T2D).Methods We conducted a retrospective cohort study of 33,238 patients with both CHD and T2D in Shenzhen,China.Patients were categorized into 6 groups based on baseline fasting plasma glucose(FPG)levels and diabetes duration(from the date of diabetes diagnosis to the baseline date)to examine their combined effects on subsequent MI.Cox proportional hazards regression models were used,with further stratification by age,sex,and comorbidities to assess potential interactions.Results Over a median follow-up of 2.4 years,2,110 patients experienced MI.Compared to those with optimal glycemic control(FPG<6.1 mmol/L)and shorter diabetes duration(<10 years),the fullyadjusted hazard ratio(HR)(95%Confidence Interval[95%CI])for those with a diabetes duration of≥10 years and FPG>8.0 mmol/L was 1.93(95%CI:1.59,2.36).The combined effects of FPG and diabetes duration on MI were largely similar across different age,sex,and comorbidity groups,although the excess risk of MI associated with long-term diabetes appeared to be more pronounced among those with atrial fibrillation.Conclusion Our study indicates that glycemic control and diabetes duration significant influence the subsequent occurrence of MI in patients with both CHD and T2D.Tailored management strategies emphasizing strict glycemic control may be particularly beneficial for patients with longer diabetes duration and atrial fibrillation.展开更多
BACKGROUND Decreased renal function is a well-known risk factor for cardiovascular diseases(CVD)and death.However,the impact of diabetes duration and the glomerular filtration rate(GFR)on cardiovascular complications ...BACKGROUND Decreased renal function is a well-known risk factor for cardiovascular diseases(CVD)and death.However,the impact of diabetes duration and the glomerular filtration rate(GFR)on cardiovascular complications in patients with type 2 dia-betes has not been well studied.AIM To investigate the complex impact of longer diabetes duration and GFR on CVD and mortality.METHODS Subjects with diabetes age≥20 years,who underwent health check-ups from 2015 to 2016 were identified in the Korean National Health Insurance Service database.Based on diabetes duration,subjects were grouped into new-onset,<5 years,5–9 years,or≥10 years.The new-onset diabetes group[estimated GFR(eGFR):≥90 mL/min/1.73 m2]was the reference group.A Cox proportional hazards model adjusted for potential confounders was used to estimate the risk for myocardial infarction(MI),ischemic stroke(IS),and mortality.RESULTS During a 3.9-year follow-up of 2105228 patients,36003(1.7%)MIs,46496(2.2%)ISs,and 73549(3.5%)deaths were documented.Both longer diabetes duration and lower eGFR were independently associated with higher risks of MI,IS,and mortality,which were further amplified when these factors coexisted.Even patients with new-onset diabetes had elevated MI and IS risk at mildly reduced eGFR(60–90 mL/min/1.73 m^(2)).Mortality risk rose appreciably once eGFR declined below 60 mL/min/1.73 m^(2),particularly in those with longer diabetes duration.eGFR≥90 mL/min/1.73 m2 subgroups had higher death risk than eGFR 60–90 mL/min/1.73 m2 subgroups regardless of diabetic duration.CONCLUSION Increasing diabetes duration and decreasing eGFR are associated with increased risk of MI,IS,and mortality.For cardiovascular risk estimation,diabetes duration should be considered an important risk factor.展开更多
To investigate the influence of non-uniform water distribution on the mechanical properties and failure behavior of red sandstone,we designed five immersion heights and durations to achieve varying non-uniform water d...To investigate the influence of non-uniform water distribution on the mechanical properties and failure behavior of red sandstone,we designed five immersion heights and durations to achieve varying non-uniform water distribution states.Uniaxial compression tests were conducted on red sandstone under these conditions.The effects of non-uniform water distribution on deformation,failure,strength,and energy characteristics of red sandstone were analyzed.The impact of non-uniform water distribution on the intensity of rock failure was discussed,and the failure mechanism under non-uniform water distribution was revealed.The hazards of low immersion heights on underground rock structures were analyzed.The results demonstrate that peak strength and elastic modulus of red sandstone exhibit high sensitivity to immersion height,with reductions of 38%and 23%respectively even at L=1/50H.Water immersion reduces both energy storage capacity and energy dissipation capability of red sandstone.The immersion height and duration influence the failure mode of red sandstone by controlling the migration and separation of dry-wet interfaces.Low immersion height poses significant risks to underground rock structures(e.g.,a 38%strength reduction when L=1/50H),and the concentration degree of water non-uniform distribution is the key factor in assessing the weakening effect of water on rocks.展开更多
Avian incubation is characterised by the contact between the eggs and the bird's skin to transfer heat to increase egg temperature above ambient conditions. Birds can be attentive to the clutch all of the time or,...Avian incubation is characterised by the contact between the eggs and the bird's skin to transfer heat to increase egg temperature above ambient conditions. Birds can be attentive to the clutch all of the time or, particularly if only one parent incubates, attentiveness may be quite low. Attentiveness is related to egg size with large eggs having high attentiveness, whereas small eggs (<10 g) can have attentiveness ranging from 50% to 100%. Previous studies have suggested that incubation duration is a function of attentiveness albeit for small birds. This study tested the hypothesis that, after controlling for egg size and phylogeny, incubation duration would be a function of attentiveness. Data for 444 bird species representing 24 orders were analysed. Whilst egg mass had a significant relationship with incubation duration, there was no relationship with attentiveness for all of the species or a subset of the passerines. Despite egg temperature drops during an incubation recess, average day-time and night-time temperatures are similar in a range of species. Re-examination of previously reported temperature profiles recorded by dummy eggs over a 24-h period shows that after an incubation recess there seems to be an additional heat flux that raises egg temperature above that seen during night-time periods of constant incubation. The reasons why eggs under intermittent incubation are not considerably cooler than eggs during constant incubation are discussed.展开更多
BACKGROUND Sleep disorders are common health problems in the elderly.The effect of social isolation on sleep duration and sleep quality remains unclear in the Chinese community-dwelling elderly.AIM To explore the asso...BACKGROUND Sleep disorders are common health problems in the elderly.The effect of social isolation on sleep duration and sleep quality remains unclear in the Chinese community-dwelling elderly.AIM To explore the associations of social isolation with sleep duration and sleep quality in community-dwelling elderly people.METHODS A total of 7762 community-dwelling elderly people aged 60 years and older in Ningbo were recruited from June 2022 to August 2022.Data were collected using a questionnaire.Multivariate logistic regression was used to analyze the associations of social isolation with sleep duration and sleep quality.The KHB mediating effect model was used to test the mediating effect of depression and anxiety on these associations.RESULTS Among the participants,2656(34.2%)had abnormal sleep duration(<6 hours or>8 hours),1115(14.4%)had poor sleep quality,and 917(11.8%)had social isolation.After adjusting for confounding factors,compared with the elderly without social isolation,the odds ratios(95%CI)of abnormal sleep duration and poor sleep quality in the elderly with social isolation were 1.49(1.29-1.73)and 1.32(1.09-1.59),respectively.Depression partially mediated the associations of social isolation with sleep duration and sleep quality,accounting for 5.68%and 9.87%of the mediating effect,respectively.CONCLUSION Social isolation was found to be associated with sleep duration and sleep quality in community-dwelling elderly people.More attention should be paid to social isolation in the elderly.展开更多
This paper investigates the selective maintenance o systems that perform multi-mission in succession. Selective maintenance is performed on systems with limited break time to improve the success of the next mission. I...This paper investigates the selective maintenance o systems that perform multi-mission in succession. Selective maintenance is performed on systems with limited break time to improve the success of the next mission. In general, the duration of the mission is stochastic. However, existing studies rarely take into account system availability and the repairpersons with different skill levels. To solve this problem, a new multi-mission selective maintenance and repairpersons assignment model with stochastic duration of the mission are developed. To maximize the minimum phase-mission reliability while meeting the minimum system availability, the model is transformed into an optimization problem subject to limited maintenance resources. The optimization is then realized using an analytical method based on a self-programming function and a Monte Carlo simulation method, respectively. Finally, the validity of the model and solution method approaches are verified by numerical arithmetic examples. Comparative and sensitivity analyses are made to provide proven recommendations for decision-makers.展开更多
Objective:Immune checkpoint inhibitors(ICIs)have demonstrated substantial efficacy in patients with advanced non-small cell lung cancer(NSCLC).However,the optimal duration of ICI therapy remains unclear,and limited re...Objective:Immune checkpoint inhibitors(ICIs)have demonstrated substantial efficacy in patients with advanced non-small cell lung cancer(NSCLC).However,the optimal duration of ICI therapy remains unclear,and limited real-world data are available.The aim of this study was to evaluate the relationship between ICI therapy duration and overall survival(OS)in patients who achieved varying best overall response(BOR)during ICI treatment,and to compare patients treated for 6 to 18 months vs.at least 18 months.Methods:This retrospective cohort study included adult patients diagnosed with advanced NSCLC who received ICI therapy at the Zhejiang Cancer Hospital between 2017 and 2022.Data collection ended on May 1,2024,and statistical analysis was performed between May and June 2024.Results:Using strict entry criteria,we screened 487 patients with advanced NSCLC and identified 134 eligible patients.Among these patients,the median durations of immunotherapy and follow-up were 24.57 months and 43.60 months,respectively.The objective response rate(ORR)was 58.2%,and the median progression-free survival(PFS)was 10.6 months.Median OS was not reached.At the last follow-up,54 patients had no disease progression,and 118 patients remained alive.Patients treated with ICI therapy for≥18 months had superior survival to those treated for 6 to 18 months(P=0.039).Further analysis revealed that the survival benefit was associated with BOR during ICI therapy.Specifically,patients achieving complete response/partial response(CR/PR)who received≥18 months of ICI therapy had a trend toward longer median OS than those treated for 6 to 18 months,but the difference did not reach statistical significance(P=0.177).Patients with stable disease(SD)who received≥18 months of ICI therapy had a statistically longer median OS than those treated for 6 to 18 months(P=0.019).Among patients treated with ICIs for≥18 months,24 continued with ICI-based therapy and achieved a median PFS2 of 6.67 months,an ORR of 33.3%,and a disease control rate(DCR)of 83.3%.Conclusions:This study provides real-world evidence and novel insights into the need for continuing ICI therapy beyond 18 months in patients with advanced NSCLC who do not exhibit progressive disease.For patients achieving SD during ICI therapy,a treatment duration of at least 18 months appears appropriate.For patients achieving CR/PR,treatment decisions should be individualized according to patient-specific circumstances.However,owing to the retrospective study design,potential selection bias and confounding factors might have influenced the results.Therefore,our findings require further validation in prospective clinical studies.展开更多
Type 2 diabetes(T2D)is a global public health issue.In 2021,537 million adults were diagnosed with T2D,corresponding to 10.5%of adults aged 20 and older.^(1)T2D increases the risks for morbidity,disability,and prematu...Type 2 diabetes(T2D)is a global public health issue.In 2021,537 million adults were diagnosed with T2D,corresponding to 10.5%of adults aged 20 and older.^(1)T2D increases the risks for morbidity,disability,and premature mortality,which increased by 3%between 2000 and 2019.2 Evidence is strong that maintaining a healthy diet,engaging in regular physical activity(PA),and preventing obesity can prevent or delay the incidence of T2D.展开更多
The duration of the extratropical transition(ET)of tropical cyclones(TCs)is often closely associated with disaster intensity.Therefore,it is essential to understand the key factors that influence ET duration.Using the...The duration of the extratropical transition(ET)of tropical cyclones(TCs)is often closely associated with disaster intensity.Therefore,it is essential to understand the key factors that influence ET duration.Using the TC best-track data and reanalysis data,this study investigates the structural characteristics and key influencing factors of ET duration in the western North Pacific(WNP)during 1981–2022.Results show that,compared to TCs that undergo ET rapidly(≤12 h),TCs that experience ET slowly(≥24 h)undergo a more prolonged and complex ET process,maintaining a warm core and an upright structure for extended periods.By contrast,TCs undergoing rapid transition experience structural disintegration within 6–12 h after ET onset.Further analysis reveals that TCs with longer ET durations are characterized by stronger warm cores,more abundant moisture,weaker environmental vertical wind shear,slower translation speeds,and a longer residence time over warmer sea surface temperatures(SSTs),all of which support the maintenance of axisymmetric structures with strong warm cores.Environmental and structural factors,including cold-air intensity,vertical wind shear,TC translation speed,SST,relative humidity,TC intensity,the radius of 17 m s^(-1)wind,mean sea level pressure,and the radius of maximum wind,are found to exist significant correlation with ET duration.Cold-air intensity exhibited the highest correlation(r=–0.35),followed by TC translation speed and SST.A relative importance analysis shows that the environmental factors play a more substantial role than the internal TC structure,accounting for about 19.23%of the variance,with TC translation speed and cold-air effects explaining 11.68%.Based on the nine factors,a statistical forecasting model was developed,which shows considerable skill in predicting ET duration.展开更多
BACKGROUND Neuroendocrine dysfunction,especially involving the hypothalamic-pituitarythyroid axis,plays a critical role in the onset and progression of schizophrenia.Alterations in thyroid stimulating hormone(TSH),tri...BACKGROUND Neuroendocrine dysfunction,especially involving the hypothalamic-pituitarythyroid axis,plays a critical role in the onset and progression of schizophrenia.Alterations in thyroid stimulating hormone(TSH),triiodothyronine(T3),free T3(FT3),thyroxine(T4),and free T4 have been implicated in this process.Although previous studies have established an association between thyroid function and psychiatric symptoms,how thyroid hormone levels vary with disease duration remains underexplored.AIM To investigate duration stage-specific associations between thyroid hormones and psychotic symptoms among inpatients with stable schizophrenia.METHODS This cross-sectional study was conducted at Zigong Mental Health Center,China,and included 237 hospitalized patients with stable schizophrenia.Participants were stratified into three groups based on disease duration:0-10 years,10.1-20 years,and over 20 years.Peripheral blood samples were collected to measure serum thyroid hormone levels.Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale.Covariate-adjusted linear regression analyses were performed to assess the relationships between thyroid hormone levels and Positive and Negative Syndrome Scale sub-scale scores.RESULTS The relationship between thyroid hormones and psychotic symptoms varied by disease duration.In patients with a disease course of 0-10 years,T4[β=-0.848;95%confidence interval(CI):-1.564 to-0.133;P=0.021]and FT3(β=-2.483;95%CI:-4.693 to-0.273;P=0.028)levels were significantly inversely associated with general psychopathology scores.Among those with 10.1-20 years of disease,only TSH showed a significant negative correlation with general psychopathology(β=-1.429;95%CI:-2.348 to-0.509;P=0.003).No significant correlations were found in the>20 years group.CONCLUSION The associations between thyroid hormones and psychotic symptoms vary according to the duration of schizophrenia(T4/FT3 early;TSH mid),enabling the development of stage-adapted models and management.展开更多
Objective Sleep is fundamental to the physical and mental health of both the general population and pregnant women.Most studies have focused on the impact of certain trimester sleep behaviors on gestational complicati...Objective Sleep is fundamental to the physical and mental health of both the general population and pregnant women.Most studies have focused on the impact of certain trimester sleep behaviors on gestational complications and birth outcomes.This study aimed to explore the association between maternal sleep duration and fetal growth development from as early as 23 gestational weeks to birth.Methods A total of 803 pregnant women were prospectively enrolled.The self-reported maternal nocturnal sleep duration during all 3 trimesters was recorded.The outcome measures were reference-population-based Z-scores of fetal biometric measurements obtained through routine ultrasonographic examination.Results Using multiple linear regression,a marginally significant negative association was observed between second-trimester sleep duration and second-trimester fetal head circumference(HC)and third-trimester fetal biparietal diameter(BPD).Then the associations of long sleep duration in each trimester with fetal biometry extreme values were evaluated.A significant impact of second-trimester long sleep duration on the second-trimester BPD below the 10th percentile of the reference population was observed.Longitudinal analysis reported similar results for BPD and HC.Conclusions Overall,a negative association between sleep duration and fetal biometric measurements was observed.Long sleep durations in the second trimester might negatively impact fetal growth,particularly brain parameters,including BPD and HC.展开更多
Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-ter...Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.展开更多
The associations of volatile organic compounds(VOCs)exposure with short sleep duration(SSD)have rarely been studied.We aimed to evaluate the correlation between VOC exposure and SSD risk,while also exploring the poten...The associations of volatile organic compounds(VOCs)exposure with short sleep duration(SSD)have rarely been studied.We aimed to evaluate the correlation between VOC exposure and SSD risk,while also exploring the potential mediating influence of depressive symptoms.Blood concentrations of seven VOCs,namely benzene,toluene,ethylbenzene,m-/p-xylene,o-xylene,styrene(collectively known as BTEXS),and 1,4-dichlorobenzene,were analyzed in 2905 U.S.adults.Weighted logistic regression,quantile-based g-computation(QGC),and weighted quantile sum(WQS)regression were employed to investigate associations between selected VOCs and SSD risk.Mediation analyses were conducted to explore the potential mediating effects of depressive symptoms on these relationships.Increased blood levels of BTEXS were positively correlated with SSD risk,with odds ratios(OR)ranging from 1.130 to 1.212(all P<0.05).A nonlinear association between toluene concentration and SSD risk was observed(P for nonlinearity=0.028).Both QGC and WQS analyses indicated a positive association between co-exposure to VOCs and SSD,with styrene showing the highest positive weights(QGC:OR=1.313,95%confidence interval(CI):1.038–1.660;WQS:OR=1.386,95%CI:1.111–1.731).Furthermore,BTEXS exposure was positively linked to depressive symptoms,which in turn were significantly associated with SSD risk.Mediation analyses revealed that depressive symptoms partially mediated the relationships between individual and mixed VOCs and SSD risk,with mediation proportions ranging from 15.87%to 20.54%(all P<0.05).These findings indicated that exposure to VOCs increased SSD risk,with depressive symptoms playing a partial mediating role.展开更多
Background It remains unclear whether sleep duration and physical activity(PA)trajectories in middle-aged and older adults are associated with different risks of cardiovascular diseases(CVDs).This study aimed to explo...Background It remains unclear whether sleep duration and physical activity(PA)trajectories in middle-aged and older adults are associated with different risks of cardiovascular diseases(CVDs).This study aimed to explore the trajectories of total sleep duration and PA among middle-aged and older Chinese adults and their impact on CVD risk.Methods This study was based on the China Health and Retirement Longitudinal Study.12009 adults aged 45 years and older from five waves were included.CVD events were measured by self-reports of heart disease and stroke.We first used groupbased trajectory modeling to identify total sleep duration and PA trajectories from 2011 to 2020,and then employed logistic regression models to analyze their risk for CVD.Results We identified three sleep duration and PA trajectories.The risk of heart disease increased by 33%(OR=1.31,95%CI:1.12-1.53)for the short sleep duration trajectory(vs.moderate sleep duration trajectory),by 40%(OR=1.40,95%CI:1.06-1.84)for the high decreasing PA trajectory,and by 20%(OR=1.20,95%CI:1.01-1.42)for the low stable PA trajectory(vs.high stable PA trajectory),respectively.Similar results for stroke and CVD as the outcomes were also observed,but the higher risk of stroke in the high decreasing PA trajectory group was not statistically significant.The joint effects of sleep and PA showed lower risks of heart disease and stroke in trajectories with moderate or long sleep duration and high stable PA compared with short sleep duration and a low stable PA trajectory.Conclusions Short total sleep duration,high decreasing PA,and low stable PA trajectories could increase the risk of CVDs among middle-aged and older adults.Long-term moderate to long total sleep durations and high stable PA trajectories might be optimal for preventing CVDs.展开更多
Geomagnetic substorms release plasma and energy from the magnetotail to the inner magnetosphere and high latitude ionosphere.In this study,we investigate substorms of different time duration,observed during the years ...Geomagnetic substorms release plasma and energy from the magnetotail to the inner magnetosphere and high latitude ionosphere.In this study,we investigate substorms of different time duration,observed during the years 1982 to 2012.We measure substorm duration by a method based on the SME index.Our results demonstrate that longer-duration substorms occur more frequently during solar maximum years,and more frequently between the months of May and July,likely due to the higher polar ionospheric conductivity and more sunward geomagnetic pole directions during summer in the northern hemisphere.Additionally,longer substorms occur more frequently under stronger,longer-lasting southward IMF,and are accompanied by slower solar winds,suggesting that extended magnetic reconnection is required to drive longer substorms.Substorm durations are not significantly related to the minimum SML index,but longer substorms usually have higher SMU and continuously rising PC indices.The SME indices of long-duration substorms show a bimodal MLT distribution located near midnight and dusk after substorm onset,with the peak originally at midnight moving eastward to the morning side during the late recovery phase.Longer duration substorms have a stronger effect on the overall ring current at all MLT sectors except dawnside.Our results provide new insights into the development process and influencing factors of substorms,from the expansion phase to the recovery phase.展开更多
[Objective] The aim was to study on the effect of hosts on development and reproduction of mealybug （Phenacoccus solenopsis Tinsley）. [Method] Observation was conducted on developmental durations and fecundity of Ph...[Objective] The aim was to study on the effect of hosts on development and reproduction of mealybug （Phenacoccus solenopsis Tinsley）. [Method] Observation was conducted on developmental durations and fecundity of Phenacoccus solenopsis Tinsley fed on Gossypium spp., Nicotiana tabacum, Solanum tuberosum L and Hibiscus rosa-sinensis. [Result] There were differences among all durations, generation durations and fecundities of the mealybug adult females. Specifically, the generation durations on cotton （Gossypium spp.）, tobacco（ Nicotiana tabacum）, potato （Solanum tuberosum L） and Hibiscus rosa-sinensis were 30.2, 28.2, 37.3, and 27.7 d, and the fecundities per female were 626.0, 417.2, 552.5, and 183.2 ind., respectively. [Conclusion] The mealybug would have strong pontential in population growth when fed on cotton, tobacco and potato.展开更多
[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regr...[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation.[ Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [ Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be： planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm^2.展开更多
[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 195...[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 1951 to 2009,the annual,seasonal,and monthly variation of sunshine duration in recent 60 years were analyzed,as well as its relationship with meteorological factors,and sunshine duration was detected by means of climate mutation theory.[Result] Annual sunshine duration in Dalian in recent 60 years showed decrease trend on the whole,and its climatic variation rate was-3.31 h/a,with larger annual variation,namely the difference between maximum value(1978) and minimum value(2003) reached 681 h;there was obvious seasonal variation in sunshine duration,with the order of autumn>summer>winter>spring,and their climatic variation rate were-1.18,-1.15,-0.91 and-0.62 h/a;except for March,sunshine duration in each month went down,especially October,while there was slight increase in March;sunshine percentage had inverse correlation relationship with total cloudiness,relative humidity and heavy fog days;annual sunshine duration reduced abruptly around 1983.[Conclusion] Our study could provide scientific foundation for the development of agriculture and forestry in Dalian City.展开更多
Earned duration management(EDM)is a methodology for project schedule management(PSM)that can be considered an alternative to earned value management(EVM).EDM provides an estimation of devia-tions in schedule and a fin...Earned duration management(EDM)is a methodology for project schedule management(PSM)that can be considered an alternative to earned value management(EVM).EDM provides an estimation of devia-tions in schedule and a final project duration estimation.There is a key difference between EDM and EVM:In EDM,the value of activities is expressed as work periods;whereas in EVM,value is expressed in terms of cost.In this paper,we present how EDM can be applied to monitor and control stochastic pro-jects.To explain the methodology,we use a real case study with a project that presents a high level of uncertainty and activities with random durations.We analyze the usability of this approach according to the activities network topology and compare the EVM and earned schedule methodology(ESM)for PSM.展开更多
Duration models are one of the important parameters in ground-motion simulations.This model varies in different study areas,and plays a critical role in nonlinear structural response analysis.Currently,available empir...Duration models are one of the important parameters in ground-motion simulations.This model varies in different study areas,and plays a critical role in nonlinear structural response analysis.Currently,available empirical models are being globally used in ground-motion simulations,with limited research focusing on path duration in specific regions.In this study,we collected 6,486 sets of three-component strong-motion records from 29 K-NET stations in the Sagami Bay,Japan,and its surrounding areas between January 2000 to October 2018.We extracted the effective duration of 386 pieces of ground-motion records by manually picking up the S-wave arrival time and calculating the significant duration.We then obtained the path duration model of the study area based on the empirical equation of dynamic corner frequency and source duration of Boore(2009).Compared with the results of the available empirical models,the Fourier spectrum of the simulated ground motion from our effective duration model showed higher accuracy in the long-term range,with less fitting residuals.This path duration model was then applied to simulate two earthquakes of M_(W)5.4 and M_(W)6.2,respectively,in the region using the stochastic finite-fault method with a set of reliable source,path,and site parameters determined for the study area.The simulation results of most stations fit well with observation records in the 0-30 Hz frequency band.For the M_(W)5.4 earthquake,the simulated ground motions at KNG005/KNG010/SZO008 stations were relatively weak in the mid to high frequency band(1-30 Hz)because the quality factor and geometric diffusion model used in the simulation were the averages of the entire Sagami Bay region,causing a bias in the results of a few stations owing to local crustal velocity anomalies and topographic effects.For the M_(W)6.2 earthquake,the simulated ground motions were relatively weak at all SZO and TKY stations,mainly because of the close distance from these stations to the epicenter and the complex seismic-wave propagation paths.The analysis suggests that the differences between the simulation results of the two earthquakes were mainly related to complex geological conditions and seismic-wave propagation paths.展开更多
基金supported by the R&D project of Pazhou Lab(Huangpu)under Grant 2023K0610the National Natural Science Foundation of China(Grants 12126602)+4 种基金the National Natural Science Foundation of China(Grants 82030102)the Shenzhen Medical Research Fund(Grants C2302001)the Shenzhen Science and Technology Innovation Committee(No.ZDSYS20200810171403013)the Chinese Postdoctoral Science Foundation(No.2022M721463)the Ministry of Science and Technology of China(Grants 2022YFC3702703).
文摘Objective This study aimed to investigate the impact of glycemic control and diabetes duration on subsequent myocardial infarction(MI)in patients with both coronary heart disease(CHD)and type 2 diabetes(T2D).Methods We conducted a retrospective cohort study of 33,238 patients with both CHD and T2D in Shenzhen,China.Patients were categorized into 6 groups based on baseline fasting plasma glucose(FPG)levels and diabetes duration(from the date of diabetes diagnosis to the baseline date)to examine their combined effects on subsequent MI.Cox proportional hazards regression models were used,with further stratification by age,sex,and comorbidities to assess potential interactions.Results Over a median follow-up of 2.4 years,2,110 patients experienced MI.Compared to those with optimal glycemic control(FPG<6.1 mmol/L)and shorter diabetes duration(<10 years),the fullyadjusted hazard ratio(HR)(95%Confidence Interval[95%CI])for those with a diabetes duration of≥10 years and FPG>8.0 mmol/L was 1.93(95%CI:1.59,2.36).The combined effects of FPG and diabetes duration on MI were largely similar across different age,sex,and comorbidity groups,although the excess risk of MI associated with long-term diabetes appeared to be more pronounced among those with atrial fibrillation.Conclusion Our study indicates that glycemic control and diabetes duration significant influence the subsequent occurrence of MI in patients with both CHD and T2D.Tailored management strategies emphasizing strict glycemic control may be particularly beneficial for patients with longer diabetes duration and atrial fibrillation.
基金Supported by the National Research Foundation of Korea grant funded by the Korea government,No.RS-2023-00217317the Korea Health Technology R and D Project through the Korea Health Industry Development Institute funded by the Ministry of Health and Welfare,Republic of Korea,No.RS-2024-00439029.
文摘BACKGROUND Decreased renal function is a well-known risk factor for cardiovascular diseases(CVD)and death.However,the impact of diabetes duration and the glomerular filtration rate(GFR)on cardiovascular complications in patients with type 2 dia-betes has not been well studied.AIM To investigate the complex impact of longer diabetes duration and GFR on CVD and mortality.METHODS Subjects with diabetes age≥20 years,who underwent health check-ups from 2015 to 2016 were identified in the Korean National Health Insurance Service database.Based on diabetes duration,subjects were grouped into new-onset,<5 years,5–9 years,or≥10 years.The new-onset diabetes group[estimated GFR(eGFR):≥90 mL/min/1.73 m2]was the reference group.A Cox proportional hazards model adjusted for potential confounders was used to estimate the risk for myocardial infarction(MI),ischemic stroke(IS),and mortality.RESULTS During a 3.9-year follow-up of 2105228 patients,36003(1.7%)MIs,46496(2.2%)ISs,and 73549(3.5%)deaths were documented.Both longer diabetes duration and lower eGFR were independently associated with higher risks of MI,IS,and mortality,which were further amplified when these factors coexisted.Even patients with new-onset diabetes had elevated MI and IS risk at mildly reduced eGFR(60–90 mL/min/1.73 m^(2)).Mortality risk rose appreciably once eGFR declined below 60 mL/min/1.73 m^(2),particularly in those with longer diabetes duration.eGFR≥90 mL/min/1.73 m2 subgroups had higher death risk than eGFR 60–90 mL/min/1.73 m2 subgroups regardless of diabetic duration.CONCLUSION Increasing diabetes duration and decreasing eGFR are associated with increased risk of MI,IS,and mortality.For cardiovascular risk estimation,diabetes duration should be considered an important risk factor.
基金supported by the National Natural Science Foundation of China(Nos.52474133,52304227,52304091,and 52374095)the Natural Science Foundation of Hunan Province(Nos.2025JJ50316 and 2023JJ40548).
文摘To investigate the influence of non-uniform water distribution on the mechanical properties and failure behavior of red sandstone,we designed five immersion heights and durations to achieve varying non-uniform water distribution states.Uniaxial compression tests were conducted on red sandstone under these conditions.The effects of non-uniform water distribution on deformation,failure,strength,and energy characteristics of red sandstone were analyzed.The impact of non-uniform water distribution on the intensity of rock failure was discussed,and the failure mechanism under non-uniform water distribution was revealed.The hazards of low immersion heights on underground rock structures were analyzed.The results demonstrate that peak strength and elastic modulus of red sandstone exhibit high sensitivity to immersion height,with reductions of 38%and 23%respectively even at L=1/50H.Water immersion reduces both energy storage capacity and energy dissipation capability of red sandstone.The immersion height and duration influence the failure mode of red sandstone by controlling the migration and separation of dry-wet interfaces.Low immersion height poses significant risks to underground rock structures(e.g.,a 38%strength reduction when L=1/50H),and the concentration degree of water non-uniform distribution is the key factor in assessing the weakening effect of water on rocks.
文摘Avian incubation is characterised by the contact between the eggs and the bird's skin to transfer heat to increase egg temperature above ambient conditions. Birds can be attentive to the clutch all of the time or, particularly if only one parent incubates, attentiveness may be quite low. Attentiveness is related to egg size with large eggs having high attentiveness, whereas small eggs (<10 g) can have attentiveness ranging from 50% to 100%. Previous studies have suggested that incubation duration is a function of attentiveness albeit for small birds. This study tested the hypothesis that, after controlling for egg size and phylogeny, incubation duration would be a function of attentiveness. Data for 444 bird species representing 24 orders were analysed. Whilst egg mass had a significant relationship with incubation duration, there was no relationship with attentiveness for all of the species or a subset of the passerines. Despite egg temperature drops during an incubation recess, average day-time and night-time temperatures are similar in a range of species. Re-examination of previously reported temperature profiles recorded by dummy eggs over a 24-h period shows that after an incubation recess there seems to be an additional heat flux that raises egg temperature above that seen during night-time periods of constant incubation. The reasons why eggs under intermittent incubation are not considerably cooler than eggs during constant incubation are discussed.
基金Supported by Ningbo Medical and Health Brand Discipline,No.PPXK2024-07and Ningbo Top Medical and Health Research Program,No.2022030410.
文摘BACKGROUND Sleep disorders are common health problems in the elderly.The effect of social isolation on sleep duration and sleep quality remains unclear in the Chinese community-dwelling elderly.AIM To explore the associations of social isolation with sleep duration and sleep quality in community-dwelling elderly people.METHODS A total of 7762 community-dwelling elderly people aged 60 years and older in Ningbo were recruited from June 2022 to August 2022.Data were collected using a questionnaire.Multivariate logistic regression was used to analyze the associations of social isolation with sleep duration and sleep quality.The KHB mediating effect model was used to test the mediating effect of depression and anxiety on these associations.RESULTS Among the participants,2656(34.2%)had abnormal sleep duration(<6 hours or>8 hours),1115(14.4%)had poor sleep quality,and 917(11.8%)had social isolation.After adjusting for confounding factors,compared with the elderly without social isolation,the odds ratios(95%CI)of abnormal sleep duration and poor sleep quality in the elderly with social isolation were 1.49(1.29-1.73)and 1.32(1.09-1.59),respectively.Depression partially mediated the associations of social isolation with sleep duration and sleep quality,accounting for 5.68%and 9.87%of the mediating effect,respectively.CONCLUSION Social isolation was found to be associated with sleep duration and sleep quality in community-dwelling elderly people.More attention should be paid to social isolation in the elderly.
文摘This paper investigates the selective maintenance o systems that perform multi-mission in succession. Selective maintenance is performed on systems with limited break time to improve the success of the next mission. In general, the duration of the mission is stochastic. However, existing studies rarely take into account system availability and the repairpersons with different skill levels. To solve this problem, a new multi-mission selective maintenance and repairpersons assignment model with stochastic duration of the mission are developed. To maximize the minimum phase-mission reliability while meeting the minimum system availability, the model is transformed into an optimization problem subject to limited maintenance resources. The optimization is then realized using an analytical method based on a self-programming function and a Monte Carlo simulation method, respectively. Finally, the validity of the model and solution method approaches are verified by numerical arithmetic examples. Comparative and sensitivity analyses are made to provide proven recommendations for decision-makers.
基金supported by the Natural Scientific Foundation of Zhejiang Province,China(Grant No.LTGY23H160007).
文摘Objective:Immune checkpoint inhibitors(ICIs)have demonstrated substantial efficacy in patients with advanced non-small cell lung cancer(NSCLC).However,the optimal duration of ICI therapy remains unclear,and limited real-world data are available.The aim of this study was to evaluate the relationship between ICI therapy duration and overall survival(OS)in patients who achieved varying best overall response(BOR)during ICI treatment,and to compare patients treated for 6 to 18 months vs.at least 18 months.Methods:This retrospective cohort study included adult patients diagnosed with advanced NSCLC who received ICI therapy at the Zhejiang Cancer Hospital between 2017 and 2022.Data collection ended on May 1,2024,and statistical analysis was performed between May and June 2024.Results:Using strict entry criteria,we screened 487 patients with advanced NSCLC and identified 134 eligible patients.Among these patients,the median durations of immunotherapy and follow-up were 24.57 months and 43.60 months,respectively.The objective response rate(ORR)was 58.2%,and the median progression-free survival(PFS)was 10.6 months.Median OS was not reached.At the last follow-up,54 patients had no disease progression,and 118 patients remained alive.Patients treated with ICI therapy for≥18 months had superior survival to those treated for 6 to 18 months(P=0.039).Further analysis revealed that the survival benefit was associated with BOR during ICI therapy.Specifically,patients achieving complete response/partial response(CR/PR)who received≥18 months of ICI therapy had a trend toward longer median OS than those treated for 6 to 18 months,but the difference did not reach statistical significance(P=0.177).Patients with stable disease(SD)who received≥18 months of ICI therapy had a statistically longer median OS than those treated for 6 to 18 months(P=0.019).Among patients treated with ICIs for≥18 months,24 continued with ICI-based therapy and achieved a median PFS2 of 6.67 months,an ORR of 33.3%,and a disease control rate(DCR)of 83.3%.Conclusions:This study provides real-world evidence and novel insights into the need for continuing ICI therapy beyond 18 months in patients with advanced NSCLC who do not exhibit progressive disease.For patients achieving SD during ICI therapy,a treatment duration of at least 18 months appears appropriate.For patients achieving CR/PR,treatment decisions should be individualized according to patient-specific circumstances.However,owing to the retrospective study design,potential selection bias and confounding factors might have influenced the results.Therefore,our findings require further validation in prospective clinical studies.
文摘Type 2 diabetes(T2D)is a global public health issue.In 2021,537 million adults were diagnosed with T2D,corresponding to 10.5%of adults aged 20 and older.^(1)T2D increases the risks for morbidity,disability,and premature mortality,which increased by 3%between 2000 and 2019.2 Evidence is strong that maintaining a healthy diet,engaging in regular physical activity(PA),and preventing obesity can prevent or delay the incidence of T2D.
基金National Key R&D Program of China(2022YFC3004200)Science and Technology Commission of Shanghai Municipality,China(23DZ1204703)。
文摘The duration of the extratropical transition(ET)of tropical cyclones(TCs)is often closely associated with disaster intensity.Therefore,it is essential to understand the key factors that influence ET duration.Using the TC best-track data and reanalysis data,this study investigates the structural characteristics and key influencing factors of ET duration in the western North Pacific(WNP)during 1981–2022.Results show that,compared to TCs that undergo ET rapidly(≤12 h),TCs that experience ET slowly(≥24 h)undergo a more prolonged and complex ET process,maintaining a warm core and an upright structure for extended periods.By contrast,TCs undergoing rapid transition experience structural disintegration within 6–12 h after ET onset.Further analysis reveals that TCs with longer ET durations are characterized by stronger warm cores,more abundant moisture,weaker environmental vertical wind shear,slower translation speeds,and a longer residence time over warmer sea surface temperatures(SSTs),all of which support the maintenance of axisymmetric structures with strong warm cores.Environmental and structural factors,including cold-air intensity,vertical wind shear,TC translation speed,SST,relative humidity,TC intensity,the radius of 17 m s^(-1)wind,mean sea level pressure,and the radius of maximum wind,are found to exist significant correlation with ET duration.Cold-air intensity exhibited the highest correlation(r=–0.35),followed by TC translation speed and SST.A relative importance analysis shows that the environmental factors play a more substantial role than the internal TC structure,accounting for about 19.23%of the variance,with TC translation speed and cold-air effects explaining 11.68%.Based on the nine factors,a statistical forecasting model was developed,which shows considerable skill in predicting ET duration.
基金Supported by the Zigong Key Science and Technology Plan(Collaborative Innovation Project of Zigong Institute of Brain Sciences),No.2023-NKY-02-04,No.2023-NKY-02-07,No.2023-NKY-03-03,and No.2024-NKY-02-07.
文摘BACKGROUND Neuroendocrine dysfunction,especially involving the hypothalamic-pituitarythyroid axis,plays a critical role in the onset and progression of schizophrenia.Alterations in thyroid stimulating hormone(TSH),triiodothyronine(T3),free T3(FT3),thyroxine(T4),and free T4 have been implicated in this process.Although previous studies have established an association between thyroid function and psychiatric symptoms,how thyroid hormone levels vary with disease duration remains underexplored.AIM To investigate duration stage-specific associations between thyroid hormones and psychotic symptoms among inpatients with stable schizophrenia.METHODS This cross-sectional study was conducted at Zigong Mental Health Center,China,and included 237 hospitalized patients with stable schizophrenia.Participants were stratified into three groups based on disease duration:0-10 years,10.1-20 years,and over 20 years.Peripheral blood samples were collected to measure serum thyroid hormone levels.Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale.Covariate-adjusted linear regression analyses were performed to assess the relationships between thyroid hormone levels and Positive and Negative Syndrome Scale sub-scale scores.RESULTS The relationship between thyroid hormones and psychotic symptoms varied by disease duration.In patients with a disease course of 0-10 years,T4[β=-0.848;95%confidence interval(CI):-1.564 to-0.133;P=0.021]and FT3(β=-2.483;95%CI:-4.693 to-0.273;P=0.028)levels were significantly inversely associated with general psychopathology scores.Among those with 10.1-20 years of disease,only TSH showed a significant negative correlation with general psychopathology(β=-1.429;95%CI:-2.348 to-0.509;P=0.003).No significant correlations were found in the>20 years group.CONCLUSION The associations between thyroid hormones and psychotic symptoms vary according to the duration of schizophrenia(T4/FT3 early;TSH mid),enabling the development of stage-adapted models and management.
基金supported by the National Natural Science Foundation of China(No.81873843)the National Science and Technology Pillar Program of China during the Twelfth Five-Year Plan Period(No.2014BAI05B05)the Fundamental Research Funds for the Central Universities(No.2017KFYXJJ102 and 2019KFYXKJC053).
文摘Objective Sleep is fundamental to the physical and mental health of both the general population and pregnant women.Most studies have focused on the impact of certain trimester sleep behaviors on gestational complications and birth outcomes.This study aimed to explore the association between maternal sleep duration and fetal growth development from as early as 23 gestational weeks to birth.Methods A total of 803 pregnant women were prospectively enrolled.The self-reported maternal nocturnal sleep duration during all 3 trimesters was recorded.The outcome measures were reference-population-based Z-scores of fetal biometric measurements obtained through routine ultrasonographic examination.Results Using multiple linear regression,a marginally significant negative association was observed between second-trimester sleep duration and second-trimester fetal head circumference(HC)and third-trimester fetal biparietal diameter(BPD).Then the associations of long sleep duration in each trimester with fetal biometry extreme values were evaluated.A significant impact of second-trimester long sleep duration on the second-trimester BPD below the 10th percentile of the reference population was observed.Longitudinal analysis reported similar results for BPD and HC.Conclusions Overall,a negative association between sleep duration and fetal biometric measurements was observed.Long sleep durations in the second trimester might negatively impact fetal growth,particularly brain parameters,including BPD and HC.
基金supported by the National Key R&D Program of China(2023YFC2604500)the National Natural Science Foundation of China(32171662,32471753 and 32171666)the Natural Science Foundation of Liaoning(2020-MS-199).
文摘Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.
文摘The associations of volatile organic compounds(VOCs)exposure with short sleep duration(SSD)have rarely been studied.We aimed to evaluate the correlation between VOC exposure and SSD risk,while also exploring the potential mediating influence of depressive symptoms.Blood concentrations of seven VOCs,namely benzene,toluene,ethylbenzene,m-/p-xylene,o-xylene,styrene(collectively known as BTEXS),and 1,4-dichlorobenzene,were analyzed in 2905 U.S.adults.Weighted logistic regression,quantile-based g-computation(QGC),and weighted quantile sum(WQS)regression were employed to investigate associations between selected VOCs and SSD risk.Mediation analyses were conducted to explore the potential mediating effects of depressive symptoms on these relationships.Increased blood levels of BTEXS were positively correlated with SSD risk,with odds ratios(OR)ranging from 1.130 to 1.212(all P<0.05).A nonlinear association between toluene concentration and SSD risk was observed(P for nonlinearity=0.028).Both QGC and WQS analyses indicated a positive association between co-exposure to VOCs and SSD,with styrene showing the highest positive weights(QGC:OR=1.313,95%confidence interval(CI):1.038–1.660;WQS:OR=1.386,95%CI:1.111–1.731).Furthermore,BTEXS exposure was positively linked to depressive symptoms,which in turn were significantly associated with SSD risk.Mediation analyses revealed that depressive symptoms partially mediated the relationships between individual and mixed VOCs and SSD risk,with mediation proportions ranging from 15.87%to 20.54%(all P<0.05).These findings indicated that exposure to VOCs increased SSD risk,with depressive symptoms playing a partial mediating role.
基金supported by Peking University,the National Natural Science Foundation of China,the National Institute on Aging and the World Bank。
文摘Background It remains unclear whether sleep duration and physical activity(PA)trajectories in middle-aged and older adults are associated with different risks of cardiovascular diseases(CVDs).This study aimed to explore the trajectories of total sleep duration and PA among middle-aged and older Chinese adults and their impact on CVD risk.Methods This study was based on the China Health and Retirement Longitudinal Study.12009 adults aged 45 years and older from five waves were included.CVD events were measured by self-reports of heart disease and stroke.We first used groupbased trajectory modeling to identify total sleep duration and PA trajectories from 2011 to 2020,and then employed logistic regression models to analyze their risk for CVD.Results We identified three sleep duration and PA trajectories.The risk of heart disease increased by 33%(OR=1.31,95%CI:1.12-1.53)for the short sleep duration trajectory(vs.moderate sleep duration trajectory),by 40%(OR=1.40,95%CI:1.06-1.84)for the high decreasing PA trajectory,and by 20%(OR=1.20,95%CI:1.01-1.42)for the low stable PA trajectory(vs.high stable PA trajectory),respectively.Similar results for stroke and CVD as the outcomes were also observed,but the higher risk of stroke in the high decreasing PA trajectory group was not statistically significant.The joint effects of sleep and PA showed lower risks of heart disease and stroke in trajectories with moderate or long sleep duration and high stable PA compared with short sleep duration and a low stable PA trajectory.Conclusions Short total sleep duration,high decreasing PA,and low stable PA trajectories could increase the risk of CVDs among middle-aged and older adults.Long-term moderate to long total sleep durations and high stable PA trajectories might be optimal for preventing CVDs.
基金supported by NSFC research Grant 42274200National Key R&D Program of China 2023YFC2808900the International Space Science Institute(ISSI)in Bern,through ISSI International Team project#24-628-Precipitation of Energetic Particles from Magnetosphere and Their Effects on the Atmosphere.
文摘Geomagnetic substorms release plasma and energy from the magnetotail to the inner magnetosphere and high latitude ionosphere.In this study,we investigate substorms of different time duration,observed during the years 1982 to 2012.We measure substorm duration by a method based on the SME index.Our results demonstrate that longer-duration substorms occur more frequently during solar maximum years,and more frequently between the months of May and July,likely due to the higher polar ionospheric conductivity and more sunward geomagnetic pole directions during summer in the northern hemisphere.Additionally,longer substorms occur more frequently under stronger,longer-lasting southward IMF,and are accompanied by slower solar winds,suggesting that extended magnetic reconnection is required to drive longer substorms.Substorm durations are not significantly related to the minimum SML index,but longer substorms usually have higher SMU and continuously rising PC indices.The SME indices of long-duration substorms show a bimodal MLT distribution located near midnight and dusk after substorm onset,with the peak originally at midnight moving eastward to the morning side during the late recovery phase.Longer duration substorms have a stronger effect on the overall ring current at all MLT sectors except dawnside.Our results provide new insights into the development process and influencing factors of substorms,from the expansion phase to the recovery phase.
基金Supported by National Science Foundation of China(31171855)Special R&D Fund for Plant Epidemic Prevention and Quarantine in Guangdong Province(Yuenongji201190)~~
文摘[Objective] The aim was to study on the effect of hosts on development and reproduction of mealybug （Phenacoccus solenopsis Tinsley）. [Method] Observation was conducted on developmental durations and fecundity of Phenacoccus solenopsis Tinsley fed on Gossypium spp., Nicotiana tabacum, Solanum tuberosum L and Hibiscus rosa-sinensis. [Result] There were differences among all durations, generation durations and fecundities of the mealybug adult females. Specifically, the generation durations on cotton （Gossypium spp.）, tobacco（ Nicotiana tabacum）, potato （Solanum tuberosum L） and Hibiscus rosa-sinensis were 30.2, 28.2, 37.3, and 27.7 d, and the fecundities per female were 626.0, 417.2, 552.5, and 183.2 ind., respectively. [Conclusion] The mealybug would have strong pontential in population growth when fed on cotton, tobacco and potato.
基金Supported by Key Agricultural R&D Program in Guizhou Province dur-ing the Eleventh Five-year Plan[NZ(2005)3001]~~
文摘[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation.[ Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [ Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be： planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm^2.
基金Supported by National Natural Science Foundation of China (40971294)Science and Technology Planning Project of Dalian Science and Technology Bureau(2009E11SF230)~~
文摘[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 1951 to 2009,the annual,seasonal,and monthly variation of sunshine duration in recent 60 years were analyzed,as well as its relationship with meteorological factors,and sunshine duration was detected by means of climate mutation theory.[Result] Annual sunshine duration in Dalian in recent 60 years showed decrease trend on the whole,and its climatic variation rate was-3.31 h/a,with larger annual variation,namely the difference between maximum value(1978) and minimum value(2003) reached 681 h;there was obvious seasonal variation in sunshine duration,with the order of autumn>summer>winter>spring,and their climatic variation rate were-1.18,-1.15,-0.91 and-0.62 h/a;except for March,sunshine duration in each month went down,especially October,while there was slight increase in March;sunshine percentage had inverse correlation relationship with total cloudiness,relative humidity and heavy fog days;annual sunshine duration reduced abruptly around 1983.[Conclusion] Our study could provide scientific foundation for the development of agriculture and forestry in Dalian City.
基金financed by the Regional Government of Castille and Leon(Spain)with Grant(VA180P20).
文摘Earned duration management(EDM)is a methodology for project schedule management(PSM)that can be considered an alternative to earned value management(EVM).EDM provides an estimation of devia-tions in schedule and a final project duration estimation.There is a key difference between EDM and EVM:In EDM,the value of activities is expressed as work periods;whereas in EVM,value is expressed in terms of cost.In this paper,we present how EDM can be applied to monitor and control stochastic pro-jects.To explain the methodology,we use a real case study with a project that presents a high level of uncertainty and activities with random durations.We analyze the usability of this approach according to the activities network topology and compare the EVM and earned schedule methodology(ESM)for PSM.
基金This study is supported by the National Natural Science Foundation of China(No.U1839202).
文摘Duration models are one of the important parameters in ground-motion simulations.This model varies in different study areas,and plays a critical role in nonlinear structural response analysis.Currently,available empirical models are being globally used in ground-motion simulations,with limited research focusing on path duration in specific regions.In this study,we collected 6,486 sets of three-component strong-motion records from 29 K-NET stations in the Sagami Bay,Japan,and its surrounding areas between January 2000 to October 2018.We extracted the effective duration of 386 pieces of ground-motion records by manually picking up the S-wave arrival time and calculating the significant duration.We then obtained the path duration model of the study area based on the empirical equation of dynamic corner frequency and source duration of Boore(2009).Compared with the results of the available empirical models,the Fourier spectrum of the simulated ground motion from our effective duration model showed higher accuracy in the long-term range,with less fitting residuals.This path duration model was then applied to simulate two earthquakes of M_(W)5.4 and M_(W)6.2,respectively,in the region using the stochastic finite-fault method with a set of reliable source,path,and site parameters determined for the study area.The simulation results of most stations fit well with observation records in the 0-30 Hz frequency band.For the M_(W)5.4 earthquake,the simulated ground motions at KNG005/KNG010/SZO008 stations were relatively weak in the mid to high frequency band(1-30 Hz)because the quality factor and geometric diffusion model used in the simulation were the averages of the entire Sagami Bay region,causing a bias in the results of a few stations owing to local crustal velocity anomalies and topographic effects.For the M_(W)6.2 earthquake,the simulated ground motions were relatively weak at all SZO and TKY stations,mainly because of the close distance from these stations to the epicenter and the complex seismic-wave propagation paths.The analysis suggests that the differences between the simulation results of the two earthquakes were mainly related to complex geological conditions and seismic-wave propagation paths.
