Import potentialities of world apple markets consist of the quantitative size and price level, and to some extent, will determine where the exported apples will be shipped to and how large the amount exported to each ...Import potentialities of world apple markets consist of the quantitative size and price level, and to some extent, will determine where the exported apples will be shipped to and how large the amount exported to each destination will be. Results indicate that apple import potentialities of European markets are the largest among world major apple trading blocks. Apple import potentialities of Asian Markets around China are not as large as Europe, but these markets are easier for China apple exports to enter. China has obvious comparative advantages in many aspects of apple production and apple marketing. In order to enhance her high-quality apple exports effective measures must be taken.展开更多
Situated in arid and semi-arid lands, the Ningxia Hui Autonomous Region is locatedat the middle reaches of the Yellow River. An adequate system of gravity irrigation was es-tablished in the north of Ningxia. Adding to...Situated in arid and semi-arid lands, the Ningxia Hui Autonomous Region is locatedat the middle reaches of the Yellow River. An adequate system of gravity irrigation was es-tablished in the north of Ningxia. Adding to abundant sunshine, strong solar radiation andmoderate heat, the agriculture is very developed. The south mountainous area of Ningxia, including both Yanchi and Tongxin counties,is short of rain, The vast lands cannot be irrigated. Nonirrigated agriculture and展开更多
The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the highresolution Weather Research and Forecasting model,enabling detailed analyses of convective instability characteri...The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the highresolution Weather Research and Forecasting model,enabling detailed analyses of convective instability characteristics and underlying causes of stability variations.Generalized potential temperature outperformed traditional potential temperature and equivalent potential temperature in capturing instability variations associated with mid-level latent heating and near-surface evaporative cooling.Local instability variance was primarily governed by potential divergence and the advection of potential instability,with these factors exhibiting out-of-phase distributions.Prior to the onset of heavy precipitation,intense downdrafts transported unstable air from higher levels into more stable regions at lower levels,increasing local near-surface instability,which contributed to the formation of heavy precipitation.During the heavy precipitation stage,vertical divergence between slantwise updrafts and downdrafts in the lowmiddle stable layers led to destabilization,supporting sustained convective development within the precipitation area.At the leading edge of the heavy precipitation,instability enhancement was primarily driven by vertical advection,and less stable air in the lower levels was transported upward,enhancing instability at higher levels.展开更多
In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edg...In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edge of the grounding grid, was observed and analyzed under artificially triggered lightning conditions. Based on circuit theory and measured current data, a π-equivalent circuit was established to simulate the transient response of the grounding grid.Nineteen return strokes from three artificially triggered lightning events were analyzed. The peak currents of the 19 return strokes range from -6.7 to -25.1 kA, and the mean value was -14.3 kA. The GPR decreased rapidly and formed a subpeak after reaching the initial peak, with the mean value of the initial peak being -148.65 kV and the mean value of the subpeak being -92.87 kV. The GPR induced by the triggered lightning currents exhibited a subpeak phenomenon. Simulation results indicate that the subpeak phenomenon is related to localized corrosion of the vertical grounding electrode. The potential difference at the grounding grid edge exhibited a multi-pulse waveform with alternating polarity, dominated by positive pulses. The peak values of both the positive and negative polarity pulses gradually decreased, with the first positive pulse displaying a significantly higher intensity than that of subsequent pulses.展开更多
Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previo...Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previous research,providing a long-term perspective on carbonyl compound variations and their environmental implica-tions.Atmospheric observations were conducted at Beijing(BJ)and Xianghe(XH)during the summer and winter months of 2018,2019,and 2023 to study the sources and impacts of carbonyl compounds in typical urban areas and peri‑urban areas.Notably,concentrations in the summer of 2023 increased compared to 2018 and 2019.The predominant carbonyl compounds—formaldehyde,acetaldehyde,and acetone—accounted for over 60%of the total.The mean values of OFP in BJ ranged from 18.55 to 58.61μg/m3,lower than those in XH(29.82 to 65.48μg/m3),with formaldehyde and acetaldehyde contributing over 80%of the total.SOAP exhibited a similar pattern,with values in XH(69.21 to 508.55μg/m3)significantly exceeding those in BJ(34.47 to 159.78μg/m3).The PMF model highlighted vehicle exhaust,secondary pollution,and biomass combustion as major sources of carbonyl compounds,emphasizing differences in source contributions between the two regions.This study’s com-parative analysis over different years and locations provides new insights into the dynamic changes in carbonyl compounds and their environmental importance.These results not only reinforce the importance of carbonyl compounds regulation but also offer a valuable reference for evaluating and refining emission control strategies during this period.展开更多
Paying an additional RMB 2 could have your next milk tea delivered by drone to your balcony in just five minutes.This small fee represents the vast potential of the trillion-yuan lowaltitude economy.
Objectives Glioblastoma multiforme(GBM)is highly resistant to apoptosis.This study investigates the role of Selenoprotein M(SELENOM),a redox-regulating protein,in the response of human glioblastoma A-172 cells to stau...Objectives Glioblastoma multiforme(GBM)is highly resistant to apoptosis.This study investigates the role of Selenoprotein M(SELENOM),a redox-regulating protein,in the response of human glioblastoma A-172 cells to staurosporine(STS)and hyperthermia.Methods A stable SELENOM-knockdown(SELENOM-KD)cell line was created.We measured reactive oxygen species(ROS),mitochondrial membrane potential(ΔΨm),cell death,and apoptotic gene expression.Results SELENOM-KD increased basal ROS levels and induced mitochondrial dysfunction.It sensitized cells to STS-induced apoptosis,enhancing the upregulation of pro-apoptotic genes.Conversely,under hyperthermia(42°C),SELENOM-KD cells exhibited significant thermoresistance,with 52%survival vs.99%death in controls,associated with suppressed pro-apoptotic signaling.Conclusions SELENOM is a critical redox and mitochondrial regulator in GBM.Its loss produces a context-dependent effect on cell fate:sensitizing to chemical apoptosis while conferring resistance to hyperthermia.SELENOM expression is a promising predictive biomarker for stratifying GBM patients for hyperthermia-based therapies.展开更多
The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on...The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on the transport of co-existing pollutants,especially combined dense and light non-aqueous phase liquids(DNAPLs and LNAPLs).In this study,column experiments investigated toluene and dichloromethane transport in a controlled water table system with varying fluctuation conditions.Results showed that both dichloromethane and toluene accumulated near the groundwater table under static water table conditions,but the concentration of dichloromethane declined more rapidly than toluene due to differences in their physicochemical properties,such as solubility,density,and hydrophobicity.Groundwater fluctuations facilitated pollutants transportation towards deeper layers,potentially resulting in unforeseen increases in pollutant volatilization and downward fluxes.The interactions between dichloromethane and toluene,including competitive adsorption,enhanced dissolution,and altered kinematic viscosities,resulted in the reduced transport potential of dichloromethane while enhancing that of toluene.Furthermore,compared to dichloromethane,the initial upward fluctuation of the water table had a more pronounced impact on toluene due to its lower solubility and volatility.The downward transport risk index assessment indicated that among various factors considered,groundwater fluctuation amplitude exerted the most significant influence on pollutant migration risk.These new findings will provide important insights into understanding and assessment of the potential transport risk associated with combined LNAPLs and DNAPLs in the natural environment.展开更多
Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-con...Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-conjugated polymers.CMPs offer extensive versatility in synthetic approaches,enabling the synthesis of cross-linked and mesoporous structures.Advances in chemical processes,structural design,and synthesis methodologies have been developed,resulting in a diverse range of CMPs with unique configurations and properties,contributing to the fast expansion of the field.CMPs are particularly notable for their ability to enable the competitive utilization ofπ-conjugated structures within mesoporous configurations,making them valuable for investigations across various domains.They have shown considerable promise in addressing fuel and environmental challenges,demonstrated by their exceptional performance in applications such as vapor adsorption,heterogeneous catalysis,light emission,light harvesting,and energy generation.This review examines the chemical engineering principles underlying CMPs,including synthesis approaches,systemic research advancements,multifunctional investigations boundaries,potential applications,and progress in synthesis,dimensionality,and morphology studies.Specifically,it offers a comparative analysis of CMPs and linear polymeric materials,aiding in the development of functional polymers.Furthermore,this review explores the primary fundamental limitations of CMPs in fuel-related domains and discusses alternative strategies,including novel synthesis methods incorporating interactions and morphologies,to address these challenges.Ultimately,this assessment aims to provide a valuable and inspiring resource for professionals in the field of fuel management,guiding future research and development efforts.展开更多
BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) a...BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.展开更多
Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in a...Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in alpine mountains with climate change.Hence,94 samples of river water were collected from 2018 to 2020 in the headwaters of the Shule River Basin to assess the nutrients spatiotemporal distribution and combined ap-proach of water quality index to assess water quality and potential sources.The findings depict that high nutrient concentrations were found to coincide with snowmelt and glacial meltwater and rainfall recharge periods,while total flux peaked from June to September due to increased runoff.Notably,total nitrogen(TN)concentrations were significantly higher near the town,primarily attributed to the replenishment of nitrate(NO_(3)^(‒)-N)from live-stock manure.The high total P(TP)was near the glacier,which was attributed to the transportation of glacial sediments into the river,and pH was another critical factor.N was the primary nutrient limiting factor for the growth of phytoplankton in river water.Although the migration and transport of nutrients have altered with climate change,river water quality is good in alpine mountains based on an overall evaluation.These findings contribute to enriching nutrient datasets and highlight the importance of water resource management and water quality assessment in sensitive and fragile alpine mountains.展开更多
Addiction,a complex and chronic neurobiological disorder,is characterized by compulsive substance use despite harmful consequences,leading to persistent alterations in brain function,particularly within the reward,mot...Addiction,a complex and chronic neurobiological disorder,is characterized by compulsive substance use despite harmful consequences,leading to persistent alterations in brain function,particularly within the reward,motivation,and decision-making systems.Despite the availability of a range of treatment options,including pharmacotherapy and behavioral therapies,relapse remains a major challenge,with many individuals struggling to maintain long-term recovery.Current treatments often show limited efficacy,underscoring the need for novel therapeutic strategies that can address the underlying neurobiological disruptions in addiction.展开更多
Eucommia ulmoides is an important economic forest tree species in China,of which the different tissues and organs are widely used in traditional medicine for their abundant bioactive ingredients.Previous studies alway...Eucommia ulmoides is an important economic forest tree species in China,of which the different tissues and organs are widely used in traditional medicine for their abundant bioactive ingredients.Previous studies always focused on the Eucommia gum,a potential alternative to natural rubber because of its“rubber plastic duality”.In recent years,Eucommia has increasingly attracted more attention and interest for its excellent nutritional and economic value,with the deepening of research and the development of products involving in the application of bioactive ingredients.However,the dietary health effects and future application prospects of the bioactive components of E.ulmoides have not been systematically summarized.Therefore,we firstly reviewed the main bioactive ingredients category,structural characteristics,extraction methods and nutritive value.Furthermore,we also summarized the wide application of bioactive ingredients in food and medicine fields.Finally,this review provides a comprehensive overview of the safety and future development of products derived from E.ulmoides,as well as exploring potential applications for its bioactive constituents,aiming to facilitate further extensive investigation into its utilization.展开更多
Lead(Pb)is a typical low-melting-point ductile metal and serves as an important model material in the study of dynamic responses.Under shock-wave loading,its dynamic mechanical behavior comprises two key phenomena:pla...Lead(Pb)is a typical low-melting-point ductile metal and serves as an important model material in the study of dynamic responses.Under shock-wave loading,its dynamic mechanical behavior comprises two key phenomena:plastic deformation and shock-induced phase transitions.The underlying mechanisms of these processes are still poorly understood.Revealing these mechanisms remains challenging for experimental approaches.Non-equilibrium molecular dynamics(NEMD)simulations are an alternative theoretical tool for studying dynamic responses,as they capture atomic-scale mechanisms such as defect evolution and deformation pathways.However,due to the limited accuracy of empirical interatomic potentials,the reliability of previous NEMD studies has been questioned.Using our newly developed machine learning potential for Pb-Sn alloys,we revisited the microstructural evolution in response to shock loading under various shock orientations.The results reveal that shock loading along the[001]orientation of Pb exhibits a fast,reversible,and massive phase transition and stacking-fault evolution.The behavior of Pb differs from previous studies by the absence of twinning during plastic deformation.Loading along the[011]orientation leads to slow,irreversible plastic deformation,and a localized FCC-BCC phase transition in the Pitsch orientation relationship.This study provides crucial theoretical insights into the dynamic mechanical response of Pb,offering a theoretical input for understanding the microstructure-performance relationship under extreme conditions.展开更多
We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-gener...We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.展开更多
The Rukwa Rift section of the East Africa Rift System presents a type setting for radiogenic helium accumulation in a petroleum free basin.As a prerequisite for accumulation,a considerable high heat flow anomaly is re...The Rukwa Rift section of the East Africa Rift System presents a type setting for radiogenic helium accumulation in a petroleum free basin.As a prerequisite for accumulation,a considerable high heat flow anomaly is required from tectonothermal events to drive the release and circulation of radiogenic helium in the continental crust.Here we apply statistical analysis on geochemical data observed in thermal springs and recorded heat flow to account for crustal helium mass balance for each tectonothermal event in the region.Our results demonstrate anomalously high heat flow~64-99 mW/m^(2) with a consistent trend of helium isotopic ratio and fluid chemistry in the Rukwa Rift.Mass balance calculation show that the whole crustal volume underlying the East Africa Helium Pool(EAHP)has a capability of producing radiogenic helium of about 9.9×10^(6) mol/yr(22×10^(-6) mol 4He/m^(2) yr)while the total radiogenic helium flux ranges between~2.39×10^(6) mol/yr and~2.68×10^(9) mol/yr.The Tanzania Craton contributes largely to radiogenic helium releasing up to 50% of the total capacity in the region.The total ^(4)He emission in the Rukwa Rift Basin is about 4.45×10^(5)-5.01×10^(8) mol/yr which is thus equivalent to 19%-21% of the total production capacity in the region.These results imply that the helium accumulation in the EAHP would have started as early as Paleoproterozoic(2.349 Ga).These results provide a qualitative and quantitative insight to assess both helium and geothermal potentiality in the region.展开更多
Neuronal plasticity,the brain's ability to adapt structurally and functionally,is essential for learning,memory,and recovery from injuries.In neurodegenerative diseases such as Alzheimer's disease and Parkinso...Neuronal plasticity,the brain's ability to adapt structurally and functionally,is essential for learning,memory,and recovery from injuries.In neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease,this plasticity is disrupted,leading to cognitive and motor deficits.This review explores the mechanisms of neuronal plasticity and its effect on Alzheimer's disease and Parkinson's disease.Alzheimer's disease features amyloid-beta plaques and tau tangles that impair synaptic function,while Parkinson's disease involves the loss of dopaminergic neurons affecting motor control.Enhancing neuronal plasticity offers therapeutic potential for these diseases.A systematic literature review was conducted using databases such as PubMed,Scopus,and Google Scholar,focusing on studies of neuronal plasticity in Alzheimer's disease and Parkinson's disease.Data synthesis identified key themes such as synaptic mechanisms,neurogenesis,and therapeutic strategies,linking molecular insights to clinical applications.Results highlight that targeting synaptic plasticity mechanisms,such as long-term potentiation and long-term depression,shows promise.Neurotrophic factors,advanced imaging techniques,and molecular tools(e.g.,clustered regularly interspaced short palindromic repeats and optogenetics)are crucial in understanding and enhancing plasticity.Current therapies,including dopamine replacement,deep brain stimulation,and lifestyle interventions,demonstrate the potential to alleviate symptoms and improve outcomes.In conclusion,enhancing neuronal plasticity through targeted therapies holds significant promise for treating neurodegenerative diseases.Future research should integrate multidisciplinary approaches to fully harness the therapeutic potential of neuronal plasticity in Alzheimer's disease and Parkinson's disease.展开更多
Carbon monoxide-from toxicity to therapeutic potential:Carbon monoxide(CO)has long been known as a toxic gas,primarily associated with environmental pollution and poisoning.Its strong affinity for hemoglobin causes th...Carbon monoxide-from toxicity to therapeutic potential:Carbon monoxide(CO)has long been known as a toxic gas,primarily associated with environmental pollution and poisoning.Its strong affinity for hemoglobin causes the formation of carboxyhemoglobin,which reduces oxygen delivery to the tissues and organs and leads to hypoxia.Despite its well-documented toxicity,previous studies have confirmed that CO also acts as a signaling molecule in the body and plays important physiological roles(Motterlini and Otterbein,2010).展开更多
Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differenc...Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differences in their crystallization-promoting efficiency,and the underlying mechanism remains unclear.In this study,a series of nucleating agents,including N,N-diphenylterephthalamide(DPTA),N,N,N-triphenyl-1,3,5-benzenetricarboxamide(TPTA),N,N-diphenyl terephthalohydrazide(DBTA),and N,N,N-tribenzoyl-1,3,5-benzenetricarbohydrazide(TBTA),were designed and synthesized to investigate the differences in their effects on the crystallization performance of PLA.Density functional theory(DFT)and molecular dynamics(MD)simulations showed that DBTA had a smaller electrostatic potential difference(66.2 kcal/mol).During the cooling process,DBTA could stably form more intermolecular hydrogen bonds with PLA and exhibit a higher interaction energy,thus theoretically enabling more efficient promotion of PLA crystallization.Further differential scanning calorimetry(DSC)results revealed that at a 0.5wt%loading of DBTA,the crystallization peak temperature of the PLA-DBTA composite reached 118.1℃during cooling,whereas no distinct crystallization peak was observed for pure PLA under identical conditions.The crystallinity of the composite was significantly increased to 58.4%compared to 14.6%of pure PLA.Moreover,under isothermal crystallization at 130℃,DBTA reduced the half-crystallization time of PLA to 2.9min,while the half-crystallization time for pure PLA was 27.4 min.Time-resolved Fourier transform infrared spectroscopy(FTIR)results also confirmed that DBTA promoted the formation of gt conformational isomers of PLA during the crystallization process.This study elucidates the mechanism behind the performance differences between structurally similar nucleating agents in regulating PLA crystallization from the perspective of molecular electrostatic potential and hydrogen bonding interactions,providing a theoretical basis for the molecular design of efficient nucleating agents.展开更多
This study presents a multi-physical modeling approach to analyze the dynamics of moisture potential and stress-deformation features near deep desiccation cracks in clayey soils under three consecutive years’climate ...This study presents a multi-physical modeling approach to analyze the dynamics of moisture potential and stress-deformation features near deep desiccation cracks in clayey soils under three consecutive years’climate variability in an arid region.A triple research approach of statistical analysis,analytical framework,and numerical modeling was used to investigate the complex thermo-hydro-mechanical behavior of desiccation-cracked soil,incorporating realistic climatic data of Qom,Iran.The results revealed the interplay between stress,strain,and pore water pressure over time,demonstrating that soil experiences significant swelling and shrinkage due to cyclic wetting and drying.The horizontal stress distribution shows compressive stress concentration at crack tips during wetting,transitioning to tensile stresses uniformly across the soil surface during drying paths.Similarly,vertical stress distributions exhibit localized compressive stresses along crack boundaries during wetting and tensile stresses during drying,highlighting the critical stress conditions at crack tips.The model differentiates between microstructural and macrostructural changes in porosity.Annual trends in micro-porosity revealed cyclic-dependent behavior,with significant volumetric changes occurring in the first year,stabilizing with successive cycles.The results also indicated that part of the volumetric changes are irreversible,with volumetric plastic strain increasing exponentially but at a decreasing rate over three years.Principal stress analysis indicates a shift from compressive to tensile stress states around cracks,driven by climate-induced wetting and drying cycles.These findings underscore the critical role of climate variability in shaping cracked soil behavior in arid regions,providing insights into the heterogeneous behavior of cracked soil surfFicial layers.展开更多
文摘Import potentialities of world apple markets consist of the quantitative size and price level, and to some extent, will determine where the exported apples will be shipped to and how large the amount exported to each destination will be. Results indicate that apple import potentialities of European markets are the largest among world major apple trading blocks. Apple import potentialities of Asian Markets around China are not as large as Europe, but these markets are easier for China apple exports to enter. China has obvious comparative advantages in many aspects of apple production and apple marketing. In order to enhance her high-quality apple exports effective measures must be taken.
文摘Situated in arid and semi-arid lands, the Ningxia Hui Autonomous Region is locatedat the middle reaches of the Yellow River. An adequate system of gravity irrigation was es-tablished in the north of Ningxia. Adding to abundant sunshine, strong solar radiation andmoderate heat, the agriculture is very developed. The south mountainous area of Ningxia, including both Yanchi and Tongxin counties,is short of rain, The vast lands cannot be irrigated. Nonirrigated agriculture and
基金funded by the Beijing Municipal Science and Technology Commission [grant number Z221100005222012]the Department of Science and Technology of Hebei Province [grant number 22375404D]+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences [grant number XDB0760303]the National Natural Science Foundation of China [grant numbers U2233218 and 42275010]the Open Foundation of the Key Open Laboratory of Urban Meteorology,China Meteorological Administration [grant number LUM-2023-06]。
文摘The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the highresolution Weather Research and Forecasting model,enabling detailed analyses of convective instability characteristics and underlying causes of stability variations.Generalized potential temperature outperformed traditional potential temperature and equivalent potential temperature in capturing instability variations associated with mid-level latent heating and near-surface evaporative cooling.Local instability variance was primarily governed by potential divergence and the advection of potential instability,with these factors exhibiting out-of-phase distributions.Prior to the onset of heavy precipitation,intense downdrafts transported unstable air from higher levels into more stable regions at lower levels,increasing local near-surface instability,which contributed to the formation of heavy precipitation.During the heavy precipitation stage,vertical divergence between slantwise updrafts and downdrafts in the lowmiddle stable layers led to destabilization,supporting sustained convective development within the precipitation area.At the leading edge of the heavy precipitation,instability enhancement was primarily driven by vertical advection,and less stable air in the lower levels was transported upward,enhancing instability at higher levels.
基金National Natural Science Foundation of China(42575091)Marine Meteorological Science and Data Center Program (2024B1212070014)。
文摘In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edge of the grounding grid, was observed and analyzed under artificially triggered lightning conditions. Based on circuit theory and measured current data, a π-equivalent circuit was established to simulate the transient response of the grounding grid.Nineteen return strokes from three artificially triggered lightning events were analyzed. The peak currents of the 19 return strokes range from -6.7 to -25.1 kA, and the mean value was -14.3 kA. The GPR decreased rapidly and formed a subpeak after reaching the initial peak, with the mean value of the initial peak being -148.65 kV and the mean value of the subpeak being -92.87 kV. The GPR induced by the triggered lightning currents exhibited a subpeak phenomenon. Simulation results indicate that the subpeak phenomenon is related to localized corrosion of the vertical grounding electrode. The potential difference at the grounding grid edge exhibited a multi-pulse waveform with alternating polarity, dominated by positive pulses. The peak values of both the positive and negative polarity pulses gradually decreased, with the first positive pulse displaying a significantly higher intensity than that of subsequent pulses.
基金supported by the National Natural Science Foundation of China(Nos.41905108 and 42130704).
文摘Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previous research,providing a long-term perspective on carbonyl compound variations and their environmental implica-tions.Atmospheric observations were conducted at Beijing(BJ)and Xianghe(XH)during the summer and winter months of 2018,2019,and 2023 to study the sources and impacts of carbonyl compounds in typical urban areas and peri‑urban areas.Notably,concentrations in the summer of 2023 increased compared to 2018 and 2019.The predominant carbonyl compounds—formaldehyde,acetaldehyde,and acetone—accounted for over 60%of the total.The mean values of OFP in BJ ranged from 18.55 to 58.61μg/m3,lower than those in XH(29.82 to 65.48μg/m3),with formaldehyde and acetaldehyde contributing over 80%of the total.SOAP exhibited a similar pattern,with values in XH(69.21 to 508.55μg/m3)significantly exceeding those in BJ(34.47 to 159.78μg/m3).The PMF model highlighted vehicle exhaust,secondary pollution,and biomass combustion as major sources of carbonyl compounds,emphasizing differences in source contributions between the two regions.This study’s com-parative analysis over different years and locations provides new insights into the dynamic changes in carbonyl compounds and their environmental importance.These results not only reinforce the importance of carbonyl compounds regulation but also offer a valuable reference for evaluating and refining emission control strategies during this period.
文摘Paying an additional RMB 2 could have your next milk tea delivered by drone to your balcony in just five minutes.This small fee represents the vast potential of the trillion-yuan lowaltitude economy.
基金the framework of the State assignment No.075-00607-25-00.
文摘Objectives Glioblastoma multiforme(GBM)is highly resistant to apoptosis.This study investigates the role of Selenoprotein M(SELENOM),a redox-regulating protein,in the response of human glioblastoma A-172 cells to staurosporine(STS)and hyperthermia.Methods A stable SELENOM-knockdown(SELENOM-KD)cell line was created.We measured reactive oxygen species(ROS),mitochondrial membrane potential(ΔΨm),cell death,and apoptotic gene expression.Results SELENOM-KD increased basal ROS levels and induced mitochondrial dysfunction.It sensitized cells to STS-induced apoptosis,enhancing the upregulation of pro-apoptotic genes.Conversely,under hyperthermia(42°C),SELENOM-KD cells exhibited significant thermoresistance,with 52%survival vs.99%death in controls,associated with suppressed pro-apoptotic signaling.Conclusions SELENOM is a critical redox and mitochondrial regulator in GBM.Its loss produces a context-dependent effect on cell fate:sensitizing to chemical apoptosis while conferring resistance to hyperthermia.SELENOM expression is a promising predictive biomarker for stratifying GBM patients for hyperthermia-based therapies.
基金supported by the National Key Research and Development Project of China(Nos.2024YFC3713802 and 2023YFC3709700)the Strategic Priority Research Program of the Chinese Academy of Sciences,China(No.XDA23030202)the Science and Technology Program for Foreign Cooperation in Fujian Province of China(No.2022I0040).
文摘The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on the transport of co-existing pollutants,especially combined dense and light non-aqueous phase liquids(DNAPLs and LNAPLs).In this study,column experiments investigated toluene and dichloromethane transport in a controlled water table system with varying fluctuation conditions.Results showed that both dichloromethane and toluene accumulated near the groundwater table under static water table conditions,but the concentration of dichloromethane declined more rapidly than toluene due to differences in their physicochemical properties,such as solubility,density,and hydrophobicity.Groundwater fluctuations facilitated pollutants transportation towards deeper layers,potentially resulting in unforeseen increases in pollutant volatilization and downward fluxes.The interactions between dichloromethane and toluene,including competitive adsorption,enhanced dissolution,and altered kinematic viscosities,resulted in the reduced transport potential of dichloromethane while enhancing that of toluene.Furthermore,compared to dichloromethane,the initial upward fluctuation of the water table had a more pronounced impact on toluene due to its lower solubility and volatility.The downward transport risk index assessment indicated that among various factors considered,groundwater fluctuation amplitude exerted the most significant influence on pollutant migration risk.These new findings will provide important insights into understanding and assessment of the potential transport risk associated with combined LNAPLs and DNAPLs in the natural environment.
基金supported by the King Khalid University,Abha,Saudi Arabiathe Deanship of Scientific Research at King Khalid University for funding this work through Large Groups Project under grant number(R.G.P.2/335/46)the Guangdong Office of Research Projects at the Provincial University(No.2024KCXTD064)。
文摘Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-conjugated polymers.CMPs offer extensive versatility in synthetic approaches,enabling the synthesis of cross-linked and mesoporous structures.Advances in chemical processes,structural design,and synthesis methodologies have been developed,resulting in a diverse range of CMPs with unique configurations and properties,contributing to the fast expansion of the field.CMPs are particularly notable for their ability to enable the competitive utilization ofπ-conjugated structures within mesoporous configurations,making them valuable for investigations across various domains.They have shown considerable promise in addressing fuel and environmental challenges,demonstrated by their exceptional performance in applications such as vapor adsorption,heterogeneous catalysis,light emission,light harvesting,and energy generation.This review examines the chemical engineering principles underlying CMPs,including synthesis approaches,systemic research advancements,multifunctional investigations boundaries,potential applications,and progress in synthesis,dimensionality,and morphology studies.Specifically,it offers a comparative analysis of CMPs and linear polymeric materials,aiding in the development of functional polymers.Furthermore,this review explores the primary fundamental limitations of CMPs in fuel-related domains and discusses alternative strategies,including novel synthesis methods incorporating interactions and morphologies,to address these challenges.Ultimately,this assessment aims to provide a valuable and inspiring resource for professionals in the field of fuel management,guiding future research and development efforts.
基金supported by the CAMS Innovation Fund for Medical Sciences (CIFMS)(No.2021-1-I2M-020)National High Level Hospital Clinical Research Funding (No.2022-PUMCH-B-109)National Natural Science Foundation of China (82402543)。
文摘BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2019QZKK0208)the National Natural Science Foundation of China(Nos.42171148 and 42330512)the Key R&D Project from the Science and Technology Department of Tibet(No.XZ202501ZY0030).
文摘Nitrogen(N)and phosphorus(P)are essential nutrients and can significantly impact primary productivity of the ecosystem causing water environmental problems.However,their cycling mechanisms are not well understood in alpine mountains with climate change.Hence,94 samples of river water were collected from 2018 to 2020 in the headwaters of the Shule River Basin to assess the nutrients spatiotemporal distribution and combined ap-proach of water quality index to assess water quality and potential sources.The findings depict that high nutrient concentrations were found to coincide with snowmelt and glacial meltwater and rainfall recharge periods,while total flux peaked from June to September due to increased runoff.Notably,total nitrogen(TN)concentrations were significantly higher near the town,primarily attributed to the replenishment of nitrate(NO_(3)^(‒)-N)from live-stock manure.The high total P(TP)was near the glacier,which was attributed to the transportation of glacial sediments into the river,and pH was another critical factor.N was the primary nutrient limiting factor for the growth of phytoplankton in river water.Although the migration and transport of nutrients have altered with climate change,river water quality is good in alpine mountains based on an overall evaluation.These findings contribute to enriching nutrient datasets and highlight the importance of water resource management and water quality assessment in sensitive and fragile alpine mountains.
基金supported by the National Natural Science Foundation of China(T2350008)the STI2030-Major Projects[2021ZD0203000(2021ZD0203003)]the Open Research Fund of the State Key Laboratory of Brain-Machine Intelligence,Zhejiang University(BMI2400014).
文摘Addiction,a complex and chronic neurobiological disorder,is characterized by compulsive substance use despite harmful consequences,leading to persistent alterations in brain function,particularly within the reward,motivation,and decision-making systems.Despite the availability of a range of treatment options,including pharmacotherapy and behavioral therapies,relapse remains a major challenge,with many individuals struggling to maintain long-term recovery.Current treatments often show limited efficacy,underscoring the need for novel therapeutic strategies that can address the underlying neurobiological disruptions in addiction.
基金financially supported by the National Natural Science Foundation of China(32201586 and 32301760)Key Specialized Research and Development Program in Henan Province(232102110218)+1 种基金Postdoctoral Research Start-Up Fund of Henan Province(HN2022112)Special Fund for Young Talents in Henan Agricultural University(30501318).
文摘Eucommia ulmoides is an important economic forest tree species in China,of which the different tissues and organs are widely used in traditional medicine for their abundant bioactive ingredients.Previous studies always focused on the Eucommia gum,a potential alternative to natural rubber because of its“rubber plastic duality”.In recent years,Eucommia has increasingly attracted more attention and interest for its excellent nutritional and economic value,with the deepening of research and the development of products involving in the application of bioactive ingredients.However,the dietary health effects and future application prospects of the bioactive components of E.ulmoides have not been systematically summarized.Therefore,we firstly reviewed the main bioactive ingredients category,structural characteristics,extraction methods and nutritive value.Furthermore,we also summarized the wide application of bioactive ingredients in food and medicine fields.Finally,this review provides a comprehensive overview of the safety and future development of products derived from E.ulmoides,as well as exploring potential applications for its bioactive constituents,aiming to facilitate further extensive investigation into its utilization.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1004300)the National Natural Science Foundation of China(Grant No.12404004)。
文摘Lead(Pb)is a typical low-melting-point ductile metal and serves as an important model material in the study of dynamic responses.Under shock-wave loading,its dynamic mechanical behavior comprises two key phenomena:plastic deformation and shock-induced phase transitions.The underlying mechanisms of these processes are still poorly understood.Revealing these mechanisms remains challenging for experimental approaches.Non-equilibrium molecular dynamics(NEMD)simulations are an alternative theoretical tool for studying dynamic responses,as they capture atomic-scale mechanisms such as defect evolution and deformation pathways.However,due to the limited accuracy of empirical interatomic potentials,the reliability of previous NEMD studies has been questioned.Using our newly developed machine learning potential for Pb-Sn alloys,we revisited the microstructural evolution in response to shock loading under various shock orientations.The results reveal that shock loading along the[001]orientation of Pb exhibits a fast,reversible,and massive phase transition and stacking-fault evolution.The behavior of Pb differs from previous studies by the absence of twinning during plastic deformation.Loading along the[011]orientation leads to slow,irreversible plastic deformation,and a localized FCC-BCC phase transition in the Pitsch orientation relationship.This study provides crucial theoretical insights into the dynamic mechanical response of Pb,offering a theoretical input for understanding the microstructure-performance relationship under extreme conditions.
基金Funded by the Natural Science Foundation of Jiangsu Province(No.BK20220626)the National Natural Science Foundation of China(No.52078068)+2 种基金Science and Technology Innovation Foundation of NIT(No.KCTD006)Jiangsu Marine Structure Service Performance Improvement Engineering Research CenterKey Laboratory of Jiangsu"Marine Floating Wind Power Technology and Equipment"。
文摘We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.
基金funded by United Kingdom Commonwealth Scholarship Commission。
文摘The Rukwa Rift section of the East Africa Rift System presents a type setting for radiogenic helium accumulation in a petroleum free basin.As a prerequisite for accumulation,a considerable high heat flow anomaly is required from tectonothermal events to drive the release and circulation of radiogenic helium in the continental crust.Here we apply statistical analysis on geochemical data observed in thermal springs and recorded heat flow to account for crustal helium mass balance for each tectonothermal event in the region.Our results demonstrate anomalously high heat flow~64-99 mW/m^(2) with a consistent trend of helium isotopic ratio and fluid chemistry in the Rukwa Rift.Mass balance calculation show that the whole crustal volume underlying the East Africa Helium Pool(EAHP)has a capability of producing radiogenic helium of about 9.9×10^(6) mol/yr(22×10^(-6) mol 4He/m^(2) yr)while the total radiogenic helium flux ranges between~2.39×10^(6) mol/yr and~2.68×10^(9) mol/yr.The Tanzania Craton contributes largely to radiogenic helium releasing up to 50% of the total capacity in the region.The total ^(4)He emission in the Rukwa Rift Basin is about 4.45×10^(5)-5.01×10^(8) mol/yr which is thus equivalent to 19%-21% of the total production capacity in the region.These results imply that the helium accumulation in the EAHP would have started as early as Paleoproterozoic(2.349 Ga).These results provide a qualitative and quantitative insight to assess both helium and geothermal potentiality in the region.
基金financially supported by King Abdulaziz University,Deanship of Scientific Research(DSR)。
文摘Neuronal plasticity,the brain's ability to adapt structurally and functionally,is essential for learning,memory,and recovery from injuries.In neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease,this plasticity is disrupted,leading to cognitive and motor deficits.This review explores the mechanisms of neuronal plasticity and its effect on Alzheimer's disease and Parkinson's disease.Alzheimer's disease features amyloid-beta plaques and tau tangles that impair synaptic function,while Parkinson's disease involves the loss of dopaminergic neurons affecting motor control.Enhancing neuronal plasticity offers therapeutic potential for these diseases.A systematic literature review was conducted using databases such as PubMed,Scopus,and Google Scholar,focusing on studies of neuronal plasticity in Alzheimer's disease and Parkinson's disease.Data synthesis identified key themes such as synaptic mechanisms,neurogenesis,and therapeutic strategies,linking molecular insights to clinical applications.Results highlight that targeting synaptic plasticity mechanisms,such as long-term potentiation and long-term depression,shows promise.Neurotrophic factors,advanced imaging techniques,and molecular tools(e.g.,clustered regularly interspaced short palindromic repeats and optogenetics)are crucial in understanding and enhancing plasticity.Current therapies,including dopamine replacement,deep brain stimulation,and lifestyle interventions,demonstrate the potential to alleviate symptoms and improve outcomes.In conclusion,enhancing neuronal plasticity through targeted therapies holds significant promise for treating neurodegenerative diseases.Future research should integrate multidisciplinary approaches to fully harness the therapeutic potential of neuronal plasticity in Alzheimer's disease and Parkinson's disease.
基金supported in part by the NIH(R01NS113556,to KA).
文摘Carbon monoxide-from toxicity to therapeutic potential:Carbon monoxide(CO)has long been known as a toxic gas,primarily associated with environmental pollution and poisoning.Its strong affinity for hemoglobin causes the formation of carboxyhemoglobin,which reduces oxygen delivery to the tissues and organs and leads to hypoxia.Despite its well-documented toxicity,previous studies have confirmed that CO also acts as a signaling molecule in the body and plays important physiological roles(Motterlini and Otterbein,2010).
基金supported by the Project of the National Science Foundation of China(Nos.52173033,51773044 and 51603047)Foshan Science and Technology Innovation Project(No.FS0AA-KJ919-4402-0145)。
文摘Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differences in their crystallization-promoting efficiency,and the underlying mechanism remains unclear.In this study,a series of nucleating agents,including N,N-diphenylterephthalamide(DPTA),N,N,N-triphenyl-1,3,5-benzenetricarboxamide(TPTA),N,N-diphenyl terephthalohydrazide(DBTA),and N,N,N-tribenzoyl-1,3,5-benzenetricarbohydrazide(TBTA),were designed and synthesized to investigate the differences in their effects on the crystallization performance of PLA.Density functional theory(DFT)and molecular dynamics(MD)simulations showed that DBTA had a smaller electrostatic potential difference(66.2 kcal/mol).During the cooling process,DBTA could stably form more intermolecular hydrogen bonds with PLA and exhibit a higher interaction energy,thus theoretically enabling more efficient promotion of PLA crystallization.Further differential scanning calorimetry(DSC)results revealed that at a 0.5wt%loading of DBTA,the crystallization peak temperature of the PLA-DBTA composite reached 118.1℃during cooling,whereas no distinct crystallization peak was observed for pure PLA under identical conditions.The crystallinity of the composite was significantly increased to 58.4%compared to 14.6%of pure PLA.Moreover,under isothermal crystallization at 130℃,DBTA reduced the half-crystallization time of PLA to 2.9min,while the half-crystallization time for pure PLA was 27.4 min.Time-resolved Fourier transform infrared spectroscopy(FTIR)results also confirmed that DBTA promoted the formation of gt conformational isomers of PLA during the crystallization process.This study elucidates the mechanism behind the performance differences between structurally similar nucleating agents in regulating PLA crystallization from the perspective of molecular electrostatic potential and hydrogen bonding interactions,providing a theoretical basis for the molecular design of efficient nucleating agents.
基金support provided by the Research Grant Office at Sharif University Technology by way of grants G4010902 and QB020105 is gratefully acknowledged.
文摘This study presents a multi-physical modeling approach to analyze the dynamics of moisture potential and stress-deformation features near deep desiccation cracks in clayey soils under three consecutive years’climate variability in an arid region.A triple research approach of statistical analysis,analytical framework,and numerical modeling was used to investigate the complex thermo-hydro-mechanical behavior of desiccation-cracked soil,incorporating realistic climatic data of Qom,Iran.The results revealed the interplay between stress,strain,and pore water pressure over time,demonstrating that soil experiences significant swelling and shrinkage due to cyclic wetting and drying.The horizontal stress distribution shows compressive stress concentration at crack tips during wetting,transitioning to tensile stresses uniformly across the soil surface during drying paths.Similarly,vertical stress distributions exhibit localized compressive stresses along crack boundaries during wetting and tensile stresses during drying,highlighting the critical stress conditions at crack tips.The model differentiates between microstructural and macrostructural changes in porosity.Annual trends in micro-porosity revealed cyclic-dependent behavior,with significant volumetric changes occurring in the first year,stabilizing with successive cycles.The results also indicated that part of the volumetric changes are irreversible,with volumetric plastic strain increasing exponentially but at a decreasing rate over three years.Principal stress analysis indicates a shift from compressive to tensile stress states around cracks,driven by climate-induced wetting and drying cycles.These findings underscore the critical role of climate variability in shaping cracked soil behavior in arid regions,providing insights into the heterogeneous behavior of cracked soil surfFicial layers.
