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Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

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Advances in Climate Change Research 2024年第2期15卷 197-210页

作者： jia WU Zhen-Yu HAN Xue-Jie gao Zheng-jia LIU National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation *** related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate ***,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation *** experiments were conducted with and without winter wheat irrigation to isolate the effects of *** showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil ***,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation *** wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum ***,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the *** analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2.d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and ***,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated ***,no notable change was found in terms of heavy rainfall events and precipitation intensity

关键词： Nonhydrostatic regional climate model Irrigation effect Extreme events North China

Correlation between carbon emissions,fuel consumption of vehicles and speed limit on expressway

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 631-642页

作者： Chao gao Jinliang Xu Miao jia Zhenhua Sun School of Highway Chang'an UniversityXi'an 710064China Shaoxing Communications Investment Group Co. Ltd.Shaoxing 312000China

This paper aimed to investigate the correlation between carbon emissions,fuel consumption,and speed limit.A theoretical model was derived based on the energy conservation law,which expresses the relationship between vehicle's fuel consumption and ***,a total of 40 sets of fuel consumption data were collected through field tests to verify the accuracy of the theoretical model at different speeds and different road longitudinal slope *** fuel consumption was then converted to carbon emissions according to the carbon emission factors specified by Intergovernmental Panel on Climate Change(IPCC).In the field experiment,two types of cars and trucks,which are most common on the expressways in China,were ***,the travel speed under different posted speed limits was obtained through the previously established model,and the carbon emission changes of different vehicle types at different limited speeds are *** results show that the speed limit has a significant impact on fuel consumption and carbon *** the speed limit increased from 80 to 12. km/h,average vehicle speeds increased about 2.%-2.%,and fuel consumption and carbon emissions increased from approximately 33%-38%.Another interesting result was that the vehicle's fuel consumption and carbon emissions are only affected by *** results of the study explore the effect of speed limits on carbon emissions and provide evidence for road managers to set reasonable speed limits.

关键词： Vehicle carbon emission Vehicle fuel consumption Posted speed limit Average speed Road longitudinal slope

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Discrete Element Modelling of Damage Evolution of Concrete Considering Meso-Structure of ITZ

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3495-3511页

作者： Weiliang gao Shixu jia Tingting Zhao Zhiyong Wang Institute of Defense Engineering Academy of Military SciencesChinese People’s Liberation ArmyBeijing100850China College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan030024China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

The mechanical properties of interfacial transition zones(ITZs)have traditionally been simplified by reducing the stiffness of cement in previous simulation methods.A novel approach based on the discrete element method(DEM)has been developed for modeling *** new approach efficiently simulates the meso-structure of ITZs,accurately capturing their heterogeneous *** against established uniaxial compression experiments confirms the precision of *** proposedmodel canmodel the process of damage evolution containing cracks initiation,propagation and *** increasing loads,cracks within ITZs progressively accumulate,culminating in macroscopic fractures that traverse themortarmatrix,forming the complex,serpentine path of *** study reveals four distinct displacement patterns:tensile compliant,tensile opposite,mixed tensile-shear,and shear opposite patterns,each indicative of different stages in concrete’s damage *** widening angle of these patterns delineates the progression of cracks,with the tensile compliant pattern signaling the initial crack appearance and the shear opposite pattern indicating the concrete model’s ultimate failure.

关键词： Discrete element method damage evolution interfacial transition zone meso-structure model

Effects of combustion temperature on the optical properties of brown carbon from biomass burning

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Journal of Environmental Sciences 2024年第3期137卷 302-309页

作者： Peng gao Rule Deng Song jia Yue Li Xuefei Wang Qian Xing School of Chemistry Sciences University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China

Biomass burning has been known as one of main sources of Brown Carbon(BrC)in *** this study,by controlling the combustion temperature at 2.0℃,350℃,and 450℃,the methanol soluble organic carbon(MSOC)and methanol insoluble carbon(MISC)from pine wood burning was collected by ***–Vis,excitation emission matrix(EEM),TEM and FTIR spectra were applied to investigate the properties of BrC *** MSOC at 2.0℃ and 350℃,all the spectral profiles of UV–Vis absorption and excitation emission matrix are almost the same,while the EEM of MSOC at 450℃ are different from that of the other *** MISC fuorescence was observed only in the case of 450℃.In the FTIR spectra,with the temperature increasing the peaks associated to the oxygen-contained functions was weakened,indicating the formation of the fuorophores with larger conjugated system,especially aromatic *** results show that biomass combustion at low temperature produces more oxygen-riched BrC,which possesses relatively lower light absorption,while at high temperature produces more aromatics hydrocarbons with relatively strong light *** results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.

关键词： Biomass burning Combustion temperature Methanol-soluble brown carbon EEM Impinger

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Effect of local openings on bearing behavior and failure mechanism of shield tunnel segments

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Underground Space 2024年第3期16卷 183-205页

作者： Xiaojing gao Pengfei Li Mingju Zhang Haifeng Wang Ziqi jia Wu Feng Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China Nantong Railway Construction Component Co. LtdNantong 226000China

Local failures(loss of concrete or reinforcement)can severely compromise the bearing capacity of shield segments,damaging the tunnel *** investigate the effects of local openings on the bearing behavior and failure mechanism,four full-scale bending tests were conducted on specimens with different opening positions and diameters;monitoring of load,displacement,and concrete strain was performed during *** test results reveal that both the opening position and diameter significantly influence the bearing characteristics of the *** failure process includes four sequential stages distinguished by three critical loads,namely the cracking,failure,and ultimate ***,the numerical model of the local failure segment was established using the elastoplastic damage constitutive relation of the concrete and verified by inversing the full-scale test *** on the numerical model,parametric analyses were performed to comprehensively investigate the influences of the opening position,concrete loss,and reinforcement loss on the bending ***,an analytical model was proposed,indicating that the opening position is the primary factor decreasing the bearing capacity,followed by the opening diameter and reinforcement *** results of this study can provide a theoretical basis for the safety assessment and remedial design of subway shield tunnels under extreme breakthrough conditions.

关键词： Shield tunnel Local opening segment Bearing behavior Failure mechanism

Photophysical properties of nitrogen-doped carbon quantum dots synthesized by graphite

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Journal of Materiomics 2024年第4期10卷 828-836页

作者： jia Liu Hailong Yu Guan Wang Shuang Yang Meichen Li Xin Zhang Yang jia Yachen {2. School of Electronic Engineering Heilongjiang UniversityHarbin150080HeilongjiangChina College of Communication and Electronic Engineering Qiqihar UniversityQiqihar161000HeilongjiangChina

Here,nitrogen-doped carbon quantum dots(N-CQDs)were successfully synthesized by the solvothermal method using graphite as the carbon source and N,N-dimethylformamide as the nitrogen *** characterized the structure and chemical constitution of N-CQDs using X-ray diffraction,Fourier transform infrared spectroscopy and X-ray photoelectron *** investigated the pump-and temperature-dependent photoluminescence(PL)properties and the dynamic exciton recombination processes of N-CQDs,using both steady-state and time-resolved PL *** spectral results show that the PL emission peak located at 518 nm at room temperature,mainly originates from the n-π∗transition on the surface of *** pump fluence and PL integral intensity were analyzed to demonstrate the existence of single-photon excitation under the 405 nm laser *** the temperature increases,the non-radiative transition gradually increases,which decreases the PL intensity,the full width at half maxima first narrows and then widens and the PL lifetime gradually ***,we combined the N-CQDs with chip to prepare light-emitting diode(LED).The resulting chromaticity coordinate was obtained to be(0.2.,0.40).This study offers a comprehensive understanding of the luminescence mechanism in N-doped CQDs and introduces a novel approach for the quickly fabrication of full-color display LEDs.

关键词： Carbon quantum dots Nitrogen-doped Photoluminescence Temperature-dependent Non-radiative transition

Innovative mesenchymal stem cell treatments for fatty liver disease

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World Journal of Stem Cells 2024年第9期16卷 846-853页

作者： Fei-Qiong gao jia-Qi Zhu Xu-Dong Feng Department of Endocrinology Affiliated Hangzhou First People’s HospitalSchool of MedicineWestlake UniversityHangzhou 310003Zhejiang ProvinceChina Laboratory Medicine Center Department of Clinical LaboratoryZhejiang Provincial People’s HospitalPeople’s Hospital of Hangzhou Medical CollegeHangzhou 310014Zhejiang ProvinceChina Department of Clinical Laboratory Ningbo Medical Center Lihuili HospitalAffiliated Lihuili Hospital of Ningbo UniversityNingbo 315000Zhejiang ProvinceChina

The incidence of non-alcoholic fatty liver disease(NAFLD)and alcohol-associated liver disease(ALD)is increasing year by year due to changes in the contemporary environment and dietary structure,and is an important public health problem *** is an urgent need to continuously improve the understanding of their disease mechanisms and develop novel therapeutic *** stem cells(MSCs)have shown promise as a potential therapeutic strategy in therapeutic studies of NAFLD and *** and ALD have different triggers and their specific mechanisms of disease progression are different,but both involve disease processes such as hepatocellular steatosis and potential fibrosis,cirrhosis,and even hepatocellular *** have metabolic regulatory,anti-apoptotic,antioxidant,and immunomodulatory effects that together promote liver injury repair and functional recovery,and have demonstrated positive results in preclinical *** editorial is a continuum of jiang et al’s review focusing on the advantages and limitations of MSCs and their derivatives as therapeutics for NAFLD and *** detail how MSCs attenuate the progression of NAFLD by modulating molecular pathways involved in glucolipid metabolism,inflammation,oxidative stress,endoplasmic reticulum stress,and *** on recent advances,we discuss MSCs and their derivatives as therapeutic strategies for NAFLD and ALD,providing useful information for their clinical application.

关键词： Alcohol-associated liver disease Non-alcoholic fatty liver disease Mesenchymal stem cells Cell therapy Inflammation

Glucose-sensitive Membrane with PBA-based Contraction-type Linear Polymer as Chemical Valves Prepared by Surface Grafting

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Chinese Journal of Polymer Science 2024年第8期42卷 1067-1076页

作者： Chun-Peng Zhang Si-jia gao Ying Luo Lei Zou Yong-Jun Zhang State Key Laboratory of Separation Membranes and Membrane Processes School of Material Science and EngineeringTiangong UniversityTianjin 300387China State Key Laboratory of Separation Membranes and Membrane Processes School of Pharmaceutical SciencesTiangong UniversityTianjin 300387China Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases Institute of Hepatobiliary DiseaseNankai University Affiliated Third Center HospitalTianjin 300170China Cangzhou Institute of Tiangong University Cangzhou 061000China

Glucose-sensitive membrane has potential application in self-regulating insulin *** acid(PBA)is a well-known glucose ***,most PBA-based glucose-sensitive materials are expansion-type,which are not suitable as chemical valves in membrane pores for self-regulating insulin *** to a new glucose-sensitive mechanism,we synthesized PBA-based contraction-type glucose-sensitive liner polymer and ***,a glucose-sensitive membrane was prepared by grafting PBA-based contraction-type glucose-sensitive linear polymer on the membrane *** adjusting the chain length and chain density,the glucose-sensitivity of the membrane was *** membrane can reversibly regulate insulin release at physiologically relevant glucose concentrations in simulates body fluids and fetal bovine *** membrane also has good stability,anti-fouling and biocom *** has potential application in selfregulating insulin release.

关键词： Phenylboronic acid Glucose-sensitive Membrane Surface grafting Insulin

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Optimized parameters of downhole all-metal PDM based on genetic algorithm

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Petroleum Science 2024年第4期21卷 2663-2676页

作者： jia-Xing Lu Ling-Rong Kong Yu Wang Chao Feng Yu-Lin gao China University of Geosciences (Beijing) Key Laboratory on Deep Geo-Drilling Technology of Ministry of Natural Resources

Currently, deep drilling operates under extreme conditions of high temperature and high pressure,demanding more from subterranean power motors. The all-metal positive displacement motor, known for its robust performance, is a critical choice for such drilling. The dimensions of the PDM are crucial for its performance output. To enhance this, optimization of the motor's profile using a genetic algorithm has been undertaken. The design process begins with the computation of the initial stator and rotor curves based on the equations for a screw cycloid. These curves are then refined using the least squares method for a precise fit. Following this, the PDM's mathematical model is optimized, and motor friction is assessed. The genetic algorithm process involves encoding variations and managing crossovers to optimize objective functions, including the isometric radius coefficient, eccentricity distance parameter,overflow area, and maximum slip speed. This optimization yields the ideal profile parameters that enhance the motor's output. Comparative analyses of the initial and optimized output characteristics were conducted, focusing on the effects of the isometric radius coefficient and overflow area on the motor's performance. Results indicate that the optimized motor's overflow area increased by 6.9%, while its rotational speed reduced by 6.58%. The torque, as tested by Infocus, saw substantial improvements of38.8%. This optimization provides a theoretical foundation for improving the output characteristics of allmetal PDMs and supports the ongoing development and research of PDM technology.

关键词： Positive displacement motor Genetic algorithm Profile optimization Matlab programming Overflow area