There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and grea...There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.展开更多
Global food production faces enormous challenges in increasing yields while promoting environmental sustainability.A field experiments in the ecotone between the Yangtze River Basin and the HuangHuai-Hai Plain evaluat...Global food production faces enormous challenges in increasing yields while promoting environmental sustainability.A field experiments in the ecotone between the Yangtze River Basin and the HuangHuai-Hai Plain evaluated the effects of changing preceding crop rotation cycles(wheat and rapeseed)on long-term wheat-rice(W)and rapeseed-rice(R)rotation systems.A comprehensive evaluation of crop rotation systems was conducted using life cycle assessment,considering productivity,economic benefits,carbon footprint(CF),and soil health.Compared with fallow-rice rotation(F),alternating rapeseed and wheat rotations increased equivalent yield by 60.4%-82.2%,reduced CF by 0.3%-5.7%,and improved soil health by 0.3%-47.5%.Additionally,adding rapeseed to rotations increased soil nutrient content and raised soil organic carbon stocks by 31.3%-40.5%.The 3R rotation(3-year rapeseed-rice and 1-year wheat-rice)boosted rice yield by 82.2%and annual economic benefits by 84.4%,offering an effective model for optimizing long-term R rotations.Similarly,the 2W rotation(2-year wheat-rice and 1-year rapeseed rice)enhanced rice yield by 70.0% and annual economic benefits by 65.9%,providing a successful example for optimizing long-term W rotations.The 3R rapeseed-based rotation and the 2W wheatbased rotation demonstrated good environmental sustainability.These rotation systems have broad potential in sustainable intensive farming,especially in China and similar regions.展开更多
Bends contribute to a flexible layout of pipeline system,but also lead to intensive energy costs due to the complex flow characteristic.This experimental study is conducted to investigate the impact of a single coarse...Bends contribute to a flexible layout of pipeline system,but also lead to intensive energy costs due to the complex flow characteristic.This experimental study is conducted to investigate the impact of a single coarse particle on the flow field in a bend.The velocity profiles of fluid on the axial symmetry plane of the bend are measured using time-resolved particle image velocimetry.The flow structures are extracted using the proper orthogonal decomposition method.The results reveal that there is a shear-layer flow in the bend during the transportation.With the increase in particle size,the particle has a dominant influence on the flow energy distribution of the overall flow.The impact of particles on the first few energetic flows is mainly in the latter part of the transportation,both temporally and spatially.As the particle size decreases,the most energetic unsteady flow within the bend changes from the convective flow to the flow of the shear layer.展开更多
Recent evidence suggests that low-intensity extracorporeal shock wave therapy(Li-ESWT)is a promising treatment for chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS);however,its safety in pelvic organs,particul...Recent evidence suggests that low-intensity extracorporeal shock wave therapy(Li-ESWT)is a promising treatment for chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS);however,its safety in pelvic organs,particularly prostate tissues and cells,remains unclear.The current study evaluates the risks of prostate cell damage or oncogenesis following the administration of LiESWT for prostatitis.To this end,a robust in vitro model(Cell Counting Kit-8[CCK-8]assay,clone formation assay,cell scratch assay,lactate dehydrogenase[LDH]release assay,flow cytometry,and immunoblotting assay)was designed to examine the effects of Li-ESWT on cell proliferation,clonogenicity,migration,membrane integrity,and DNA damage.Exome sequencing of Li-ESWTtreated cells was performed to determine the risk of carcinogenesis.Furthermore,an in vivo rat model(n=20)was employed to assess the effects of Li-ESWT on cancer biomarkers(carcinoembryonic antigen[CEA],Ki67,proliferating cell nuclear antigen[PCNA],and gamma-H2A histone family member X,phosphorylation of the H2AX Ser-139[γ-H2AX])in prostate tissue.Based on our findings,Li-ESWT promotes cellular growth and motility without inducing significant cell membrane or DNA damage or alterations.Genetic analyses did not demonstrate an increase in mutations,and no damage to prostate tissue or upregulation of cancer biomarkers was detected in vivo.This comprehensive in vitro and in vivo assessment confirms the safety of Li-ESWT in managing prostate disorders.展开更多
Si-based materials have shown great potential as lithium-ion batteries(LIBs)anodes due to their natural reserves and high theoretical capacity.However,the large volume changes during cycles and poor conductivity of Si...Si-based materials have shown great potential as lithium-ion batteries(LIBs)anodes due to their natural reserves and high theoretical capacity.However,the large volume changes during cycles and poor conductivity of Si lead to rapid capacity decay and poor cycling stability,ultimately limiting their commercial applications.Herein,we have skillfully utilized the microporous MCM-22 zeolite as the unique silicon source to produce porous Si(pSi)sheets by a simple magnesiothermic reduction,followed by a carbon coating and further Ti_(3)C_(2)T_(x)MXene assembly,obtaining the ternary pSi@NC@TNSs composite.In the design,porous Si sheets provide more active sites and shorten Li-ion transport paths for electrochemical reactions.The N-doped carbon(NC)layer serves as a bonding layer to couple pSi and Ti_(3)C_(2)T_(x).The conductive network formed by 2D Ti_(3)C_(2)T_(x)and medium NC layer effectively enhances the overall charge transport of the electrode material,and helps to stabilize the electrode structure.Therefore,the as-made pSi@NC@TNSs anode delivers an improved lithium storage performance,exhibiting a high reversible capacity of 925 mAh/g at 0.5 A/g after 100 cycles.This present strategy provides an effective way towards high-performance Si-based anodes for LIBs.展开更多
Measurement of bloodflow velocity is key to understanding physiology and pathology in vivo.While most measurements are performed at the middle of the blood vessel,little research has been done on characterizing the in...Measurement of bloodflow velocity is key to understanding physiology and pathology in vivo.While most measurements are performed at the middle of the blood vessel,little research has been done on characterizing the instantaneous bloodflow velocity distribution.This is mainly due to the lack of measurement technology with high spatial and temporal resolution.Here,we tackle this problem with our recently developed dual-wavelength line-scan third-harmonic generation(THG)imaging technology.Simultaneous acquisition of dual-wavelength THG line-scanning signals enables measurement of bloodflow velocities at two radially symmetric positions in both venules and arterioles in mouse brain in vivo.Our results clearly show that the instantaneous bloodflow velocity is not symmetric under general conditions.展开更多
In this paper,the influence of forced installation caused by a hole-location error on the 3D stress distribution and damage of a composite bolted joint is investigated.An analytical model of stress distributed on comp...In this paper,the influence of forced installation caused by a hole-location error on the 3D stress distribution and damage of a composite bolted joint is investigated.An analytical model of stress distributed on composite holes is promoted,in view of non-uniform extrusion caused by forced installation.At first,non-uniform extrusion of the hole edge caused by forced installation is analyzed.According to the contact state,expression of hole deformation is given.Then,based on Hertz theory,the maximum extrusion load is obtained with help of deformation expression.By constructing an elastic foundation beam model,3D stress distributed on a hole could be analyzed according to the extrusion load.Then,stress distribution predicted by the above analytical method is compared with that provided by FE considering composite damage.Finally,a forced installation experiment is carried out to analyze the damage distribution of the joint.Results show that a central-symmetrically distributed stress is introduced by the hole-location error.With an increment of the error,strength of composite decreases due to extrusion damage.Therefore,stress presents a concave distribution on the hole.As the hole-location error exceeding 3%,stress decreases gradually due to failure of composite.Damage of holes does not exhibit a centrosymmetric distribution.Serious damage is mainly distributed on the entrance of the hole at the lower sheet.展开更多
Water seepage in soil is a fundamental problem involving various scientific and engineering fields.According to the literature,low-velocity water seepage in low-permeability porous media,such as clay,does not follow D...Water seepage in soil is a fundamental problem involving various scientific and engineering fields.According to the literature,low-velocity water seepage in low-permeability porous media,such as clay,does not follow Darcy's law,also known as pre-Darcy flow.The formation of immovable water due to water adsorption on the pore wall is believed to be responsible for the formation of pre-Darcy flow.However,this view lacks direct solid evidence.To investigate the pre-Darcy water flow in clay,head permeability experiments are conducted on six clay samples with different densities.The results indicate that water seepage in clay at low hydraulic gradients does not follow Darcy's law.A clear nonlinear relationship between flow velocity and hydraulic gradient is observed.Water flow in clay can be divided into the pre-Darcy flow and Darcy flow regions by the critical hydraulic gradient,which is 10-12 for the Albic soil with dry density between 1.3 g/cm^(3)and 1.8 g/cm^(3).According to the disjoining pressure theory,immovable water due to water adsorption on the pore wall is the primary reason for water flow deviating from Darcy's law in clay.The results indicate that the percentage of movable water ranges from 39.7%to 59.3%for the six samples at a hydraulic gradient of 1.As the hydraulic gradient increases,the percentage of moveable water also increases.Additionally,there is a strong correlation between the percentage of movable water and the variation in hydraulic conductivity with the hydraulic gradient.Furthermore,a quantitative relationship between the percentage of movable water and the hydraulic conductivity has been established.The results of this study suggest that water adsorption on the pore wall not only affects the water movability,but is also closely related to the pre-Darcy flow phenomenon in clay.展开更多
Background:With the rapid aging of China’s population and the increasing prevalence of comorbidities in the elderly,psychological crises have become more common.This study aims to investigate the present status of ps...Background:With the rapid aging of China’s population and the increasing prevalence of comorbidities in the elderly,psychological crises have become more common.This study aims to investigate the present status of psychological vulnerability,aging attitudes,and life meaning in elderly patients with comorbidities.Methods:A total of 685 elderly inpatients and outpatients at Renmin Hospital of Wuhan University between July and December 2022 were selected using the simple random sampling method.Social demographic data were collected,and the Attitudes to aging Questionnaire(AAQ),the Chinese Life Meaning Questionnaire(C-MLQ),and the Psychological Vulnerability Scale(C-PVS)were used for the analysis.A total of 685 questionnaires were received,and 602 valid questionnaires were collected,with an effective rate of 87.88%.Data analysis was performed using SPSS V25.0 and AMOS V24.0.Results:The total scores of psychological vulnerability,aging attitudes,and life meaning were 69.4±12.8,80.2±13.5 and 39.2±8.3,respectively.The psychological vulnerability was significantly negatively correlated with life meaning and aging attitudes(r=-0.351,-0.264;p<0.01).There was a significant positive correlation between aging attitudes and life meaning(r=0.515;p<0.01).Life meaning played a partial mediating role between psychological vulnerability and aging attitudes(β=3.070,p<0.05).Conclusion:This study found that the psychological vulnerability in elderly patients with comorbidities was at the lower level,which was related to the elderly patients’aging attitudes and their current status of life meaning.The level of psychological vulnerability in elderly patients with senile-related comorbidities needs to be further improved.Medical workers should pay attention to the psychological vulnerability of elderly patients and improve the identification of psychological crises of such patients.展开更多
This paper discusses the optimization strategy of education and teaching quality assurance systems in applied colleges and universities under the background of digital intelligence.It first summarizes the relevant the...This paper discusses the optimization strategy of education and teaching quality assurance systems in applied colleges and universities under the background of digital intelligence.It first summarizes the relevant theories of digital intelligence transformation and analyzes the impact of digital intelligence transformation on higher education.Secondly,this paper puts forward the principles of constructing the quality assurance system of applied colleges,including strengthening the quality assurance consciousness,improving teachers’digital literacy,and implementing digital intelligence governance.From the practical perspective,this paper expounds on strategies such as optimizing educational teaching resource allocation,constructing a diversified evaluation system of teaching quality,strengthening the construction and training of teaching staff,and innovating teaching management methods.Specific optimization measures are put forward,such as improving policies,regulations,and system guarantees,strengthening cooperation between schools and enterprises,integrating industry,school,and research,building an educational information platform,and improving the monitoring and feedback mechanism of educational quality.展开更多
Background:The relationship between tea intake(TI)and sleep disorders(SDs)has been a topic of interest for some time,but there remains a lack of data showing a causal relationship.We aimed to use a two-sample Mendelia...Background:The relationship between tea intake(TI)and sleep disorders(SDs)has been a topic of interest for some time,but there remains a lack of data showing a causal relationship.We aimed to use a two-sample Mendelian randomization study to determine whether there is a causal link between TI and SDs.Methods:We collected data regarding TI,with a focus on green tea intake(GTI),herbal tea intake(HTI),and rooibos tea intake(RTI);and data regarding SDs and insomnia from genome-wide association studies.We analyzed these data using an inverse variance-weighted two-sample Mendelian randomization study,by means of the TwoSampleMR package in R4.2.3 software.Results:We found no genetic causal relationships of TI,GTI,HTI,or RTI with insomnia.The odds ratios(ORs)for these relationships were as follows:TI:OR=0.61,95%confidence interval(CI):0.29–1.28;GTI:OR=1.04,95%CI:0.95–1.14;HTI:OR=0.98,95%CI:0.82–1.17;and RTI:OR=1.04,95%CI:0.99–1.09.In addition,there were no genetic causal relationships of TI,GTI,HTI,or RTI with SDs.The OR values for these relationships were as follows:TI:OR=0.6,95%CI:0.34–1.06;GTI:OR=1,95%CI:0.93–1.07;HTI:OR=0.89,95%CI:0.66–1.2;and RTI:OR=1.02,95%CI:0.98–1.06.Conclusion:We found no causal relationships of TI with SDs or insomnia,irrespective of the type of tea consumed.However,additional Mendelian randomization studies are required to further explore the relationships of the timing and quantity of tea consumption with SDs and insomnia.展开更多
Background:Telemedicine refers to the use of information technology by medical institutions to directly provide diagnostic and therapeutic services to patients outside the healthcare facility.It encompasses various as...Background:Telemedicine refers to the use of information technology by medical institutions to directly provide diagnostic and therapeutic services to patients outside the healthcare facility.It encompasses various aspects such as remote diagnosis,remote monitoring,remote consultation,and remote outpatient services.Numerous articles have evaluated its role in controlling diseases like hypertension,diabetes,atrial fibrillation,and ischemic stroke.However,the existing literature exhibits varying quality and sample sizes,lacking robust convincing power and systematic effectiveness evaluation.Methods:Following The Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 guidelines,we identified articles on remote medical intervention in ischemic stroke through databases including Web of Science,PubMed,EMBASE,Cochrane Library,CNKI,Weipu,and Wanfang.The search spanned from the inception of the databases to June 30,2022.Two researchers independently assessed literature quality,extracted data,and conducted meta-analysis using RevMan 5.3 software.Results:Ten articles,involving 5092 patients,were included.Meta-analysis results indicate that telemedicine can effectively enhance compliance with doctors’advice in ischemic stroke patients.Telemedicine is also associated with reduced stroke recurrence,moderate to severe disability,systolic and diastolic blood pressure,National Institutes of Health Stroke Scale scores,and Modified Rankin Scale scores.Additionally,telemedicine demonstrates effectiveness in improving Fugl-Meyer motor function assessment and the Barthel Index of activity of daily living in ischemic stroke patients.However,telemedicine does not significantly reduce stroke hospitalization in the past year and the death rate.Conclusion:In comparison to traditional healthcare,telemedicine exhibits advantages in improving compliance and enhancing functionality in ischemic stroke patients.It is worth promoting telemedicine for better management of ischemic stroke patients.However,this study does not explain how telemedicine improves the functionality of ischemic stroke patients,indicating a need for further research.展开更多
Carbon fiber reinforced plastic and titanium alloy(CFRP/Ti) stacks have been widely used as aerospace structures because of their excellent combination of physical properties. Interface damage caused by interface gaps...Carbon fiber reinforced plastic and titanium alloy(CFRP/Ti) stacks have been widely used as aerospace structures because of their excellent combination of physical properties. Interface damage caused by interface gaps, significantly different from that of metal/metal stacks, is a common problem in the through-hole drilling of CFRP/Ti stacks with low stiffness. In this study, a force–deformation coupling model was developed to further examine the formation mechanism and the control method of interface damage. Firstly, the coupling model was built considering the interaction between the thrust force and the deformation. To solve this model, a numerical method was proposed in which specific cutting coefficients were calibrated using only the thrust force of rigid stacks. Secondly, drilling experiments were performed with different feed rates and bending stiffness. Experimental results indicate that interface damage mainly includes interlayer chips and surface damage of CFRP layers. The surface damage, which is irreparable, is caused by the rotary extension of metal chips along the interlayer gap. Thirdly, variations of the interface gap were calculated with the coupling model that had been verified by measured thrust forces. The damage area was found to have a linear dependence relation with the interlayer gap. However, in conditions of large gap sizes, the interface damage areas increased with the interlayer gap at high feed rates, while decreasing slightly at low feed rates. This phenomenon was satisfactorily explained by the presented model. Finally, a method was proposed to determine the appropriate pressure exceeding which no interlayer damage will occur. Additional drilling experiments proved the method effective. This study leads to further understanding of the forming mechanism of interlayer damage and of selecting appropriate parameters in drilling low-stiffness composite/metal stacks.展开更多
The rapid development of electric vehicles and mobile electronic devices is the main driving force to improve advanced high-performance lithium ion batteries(LIBs).The capacity,rate performance and cycle stability of ...The rapid development of electric vehicles and mobile electronic devices is the main driving force to improve advanced high-performance lithium ion batteries(LIBs).The capacity,rate performance and cycle stability of LIBs rely directly on the electrode materials.As far as the development of the advanced LIBs electrode is concerned,the improvement of anode materials is more urgent than the cathode materials.Industrial production of anode materials superior to commercial graphite still faces some challenges.This review sets out the most basic LIBs anode material design.The reaction principles and structural design of carbon materials,various transition metal oxides,silicon and germanium are summarized,and then the progress of other anode materials are analyzed.Due to the rapid development of metal organic frameworks(MOFs)in energy storage and conversion in recent years,the synthesis process and energy storage mechanism of nanostructures derived from MOF precursors are also discussed.From the perspective of novel structural design,the progress of various MOFs-derived materials for alleviating the volume expansion of anode materials is discussed.Finally,challenges for the future development of advanced anode materials for LIBs will be considered.展开更多
Using self-researched gas drainage borehole stability dynamic monitoring device, three-dimensional deformation characteristics of borehole under steady vertical load were researched experimentally and systematically. ...Using self-researched gas drainage borehole stability dynamic monitoring device, three-dimensional deformation characteristics of borehole under steady vertical load were researched experimentally and systematically. This research indicated that under the action of steady loading, the mechanical deformation path of the simulated gas drainage borehole is gradually complicated, and the decay of the borehole circumferential strain is an important characterization of the prediction and early warning of borehole instability and collapse. The horizontal position of borehole occurs compressive strain, and the vertical of which occurs tensile strain under the action of vertical stress. At the initial stage of loading, the vertical strain is more sensitive than that in the horizontal direction. After a certain period of time, the horizontal strain is gradually higher than the vertical one, and the intersection of the borehole horizontal diameter and the hole wall is the stress concentration point. With the increase of the depth of hole, the strain shows a gradual decay trend as a whole, and the vertical strain decays more observably, but there is no absolute position correlation between the amount of strain decay and the increase in borehole depth,and the area within 1.5 times the orifice size is the borehole stress concentration zone.展开更多
A novel virtual material layer model based on the fractal theory was proposed to predict the natural frequencies of carbon fiber reinforced plastic composite bolted joints.Rough contact surfaces of composite bolted jo...A novel virtual material layer model based on the fractal theory was proposed to predict the natural frequencies of carbon fiber reinforced plastic composite bolted joints.Rough contact surfaces of composite bolted joints are modeled with this new proposed approach.Numerical and experimental modal analyses were conducted to validate the effectiveness of the proposed model.A good consistence is noted between the numerical and experimental results.To demonstrate the necessity of accurately modeling the rough contact surfaces in the prediction of natural frequencies,virtual material layer model was compared with the widely used traditional model based on the Master-Slave contact algorithm and experiments,respectively.Results show that the proposed model has a better agreement with experiments than the widely used traditional model(the prediction accuracy is raised by 8.77%when the pre-tightening torque is 0.5 N·m).Real contact area ratio A*of three different virtual material layers were calculated.Value of A*were discussed with dimensionless load P*,fractal dimension D and fractal roughness G.This work provides a new efficient way for accurately modeling the rough contact surfaces and predicting the natural frequencies of composite bolted joints,which can be used to help engineers in the dynamic design of composite materials.展开更多
基金supported by the Basic Research Development Program of China(No.JCKY2021607B036)the National Natural Science Foundation of China(No.52275512).
文摘There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.
基金supported by the National Natural Science Foundation of China(31971855)the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Science(CAAS-ASTIP-2021-OCRI)+2 种基金the Hubei Provincial Natural Science Foundation of China(2024AFB442)the Wuhan Knowledge Innovation Special Program(2023020201020400)the China Agriculture Research System(CARS-12)。
文摘Global food production faces enormous challenges in increasing yields while promoting environmental sustainability.A field experiments in the ecotone between the Yangtze River Basin and the HuangHuai-Hai Plain evaluated the effects of changing preceding crop rotation cycles(wheat and rapeseed)on long-term wheat-rice(W)and rapeseed-rice(R)rotation systems.A comprehensive evaluation of crop rotation systems was conducted using life cycle assessment,considering productivity,economic benefits,carbon footprint(CF),and soil health.Compared with fallow-rice rotation(F),alternating rapeseed and wheat rotations increased equivalent yield by 60.4%-82.2%,reduced CF by 0.3%-5.7%,and improved soil health by 0.3%-47.5%.Additionally,adding rapeseed to rotations increased soil nutrient content and raised soil organic carbon stocks by 31.3%-40.5%.The 3R rotation(3-year rapeseed-rice and 1-year wheat-rice)boosted rice yield by 82.2%and annual economic benefits by 84.4%,offering an effective model for optimizing long-term R rotations.Similarly,the 2W rotation(2-year wheat-rice and 1-year rapeseed rice)enhanced rice yield by 70.0% and annual economic benefits by 65.9%,providing a successful example for optimizing long-term W rotations.The 3R rapeseed-based rotation and the 2W wheatbased rotation demonstrated good environmental sustainability.These rotation systems have broad potential in sustainable intensive farming,especially in China and similar regions.
基金supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(Grant No.2021CXLH0003)the Innovational Fund for Scientific and Technological Personnel of Hainan Province(Grant No.KJRC2023D37).
文摘Bends contribute to a flexible layout of pipeline system,but also lead to intensive energy costs due to the complex flow characteristic.This experimental study is conducted to investigate the impact of a single coarse particle on the flow field in a bend.The velocity profiles of fluid on the axial symmetry plane of the bend are measured using time-resolved particle image velocimetry.The flow structures are extracted using the proper orthogonal decomposition method.The results reveal that there is a shear-layer flow in the bend during the transportation.With the increase in particle size,the particle has a dominant influence on the flow energy distribution of the overall flow.The impact of particles on the first few energetic flows is mainly in the latter part of the transportation,both temporally and spatially.As the particle size decreases,the most energetic unsteady flow within the bend changes from the convective flow to the flow of the shear layer.
基金supported by grants from the National Natural Science Foundation of China(No.PR0121015)the National Natural Science Foundation of China(No.82160148)the Natural Science Foundation Project of Gansu Province(No.2106RJZA110).
文摘Recent evidence suggests that low-intensity extracorporeal shock wave therapy(Li-ESWT)is a promising treatment for chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS);however,its safety in pelvic organs,particularly prostate tissues and cells,remains unclear.The current study evaluates the risks of prostate cell damage or oncogenesis following the administration of LiESWT for prostatitis.To this end,a robust in vitro model(Cell Counting Kit-8[CCK-8]assay,clone formation assay,cell scratch assay,lactate dehydrogenase[LDH]release assay,flow cytometry,and immunoblotting assay)was designed to examine the effects of Li-ESWT on cell proliferation,clonogenicity,migration,membrane integrity,and DNA damage.Exome sequencing of Li-ESWTtreated cells was performed to determine the risk of carcinogenesis.Furthermore,an in vivo rat model(n=20)was employed to assess the effects of Li-ESWT on cancer biomarkers(carcinoembryonic antigen[CEA],Ki67,proliferating cell nuclear antigen[PCNA],and gamma-H2A histone family member X,phosphorylation of the H2AX Ser-139[γ-H2AX])in prostate tissue.Based on our findings,Li-ESWT promotes cellular growth and motility without inducing significant cell membrane or DNA damage or alterations.Genetic analyses did not demonstrate an increase in mutations,and no damage to prostate tissue or upregulation of cancer biomarkers was detected in vivo.This comprehensive in vitro and in vivo assessment confirms the safety of Li-ESWT in managing prostate disorders.
基金financially supported by the Natural Science Foundation of Shanghai(No.23ZR1423800)Shuguang Program from Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.18SG35)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University.
文摘Si-based materials have shown great potential as lithium-ion batteries(LIBs)anodes due to their natural reserves and high theoretical capacity.However,the large volume changes during cycles and poor conductivity of Si lead to rapid capacity decay and poor cycling stability,ultimately limiting their commercial applications.Herein,we have skillfully utilized the microporous MCM-22 zeolite as the unique silicon source to produce porous Si(pSi)sheets by a simple magnesiothermic reduction,followed by a carbon coating and further Ti_(3)C_(2)T_(x)MXene assembly,obtaining the ternary pSi@NC@TNSs composite.In the design,porous Si sheets provide more active sites and shorten Li-ion transport paths for electrochemical reactions.The N-doped carbon(NC)layer serves as a bonding layer to couple pSi and Ti_(3)C_(2)T_(x).The conductive network formed by 2D Ti_(3)C_(2)T_(x)and medium NC layer effectively enhances the overall charge transport of the electrode material,and helps to stabilize the electrode structure.Therefore,the as-made pSi@NC@TNSs anode delivers an improved lithium storage performance,exhibiting a high reversible capacity of 925 mAh/g at 0.5 A/g after 100 cycles.This present strategy provides an effective way towards high-performance Si-based anodes for LIBs.
基金funded by the National Natural Science Foundation of China(Grant/Award Numbers 62075135 and 61975126)the Science and Technology Innovation Commission of Shenzhen(Grant/Award Numbers JCYJ20190808174819083 and JCYJ20190808175201640)Shenzhen Science and Technology Planning Project(ZDSYS 20210623092006020).
文摘Measurement of bloodflow velocity is key to understanding physiology and pathology in vivo.While most measurements are performed at the middle of the blood vessel,little research has been done on characterizing the instantaneous bloodflow velocity distribution.This is mainly due to the lack of measurement technology with high spatial and temporal resolution.Here,we tackle this problem with our recently developed dual-wavelength line-scan third-harmonic generation(THG)imaging technology.Simultaneous acquisition of dual-wavelength THG line-scanning signals enables measurement of bloodflow velocities at two radially symmetric positions in both venules and arterioles in mouse brain in vivo.Our results clearly show that the instantaneous bloodflow velocity is not symmetric under general conditions.
基金co-supported by the National Natural Science Foundation of China(No.51975472)the Fundamental Scientific Research,China(No.JCKY2021205B110).
文摘In this paper,the influence of forced installation caused by a hole-location error on the 3D stress distribution and damage of a composite bolted joint is investigated.An analytical model of stress distributed on composite holes is promoted,in view of non-uniform extrusion caused by forced installation.At first,non-uniform extrusion of the hole edge caused by forced installation is analyzed.According to the contact state,expression of hole deformation is given.Then,based on Hertz theory,the maximum extrusion load is obtained with help of deformation expression.By constructing an elastic foundation beam model,3D stress distributed on a hole could be analyzed according to the extrusion load.Then,stress distribution predicted by the above analytical method is compared with that provided by FE considering composite damage.Finally,a forced installation experiment is carried out to analyze the damage distribution of the joint.Results show that a central-symmetrically distributed stress is introduced by the hole-location error.With an increment of the error,strength of composite decreases due to extrusion damage.Therefore,stress presents a concave distribution on the hole.As the hole-location error exceeding 3%,stress decreases gradually due to failure of composite.Damage of holes does not exhibit a centrosymmetric distribution.Serious damage is mainly distributed on the entrance of the hole at the lower sheet.
基金funding support from the China National Science Foundation(Grant Nos.42072280,U2244215,41172205).
文摘Water seepage in soil is a fundamental problem involving various scientific and engineering fields.According to the literature,low-velocity water seepage in low-permeability porous media,such as clay,does not follow Darcy's law,also known as pre-Darcy flow.The formation of immovable water due to water adsorption on the pore wall is believed to be responsible for the formation of pre-Darcy flow.However,this view lacks direct solid evidence.To investigate the pre-Darcy water flow in clay,head permeability experiments are conducted on six clay samples with different densities.The results indicate that water seepage in clay at low hydraulic gradients does not follow Darcy's law.A clear nonlinear relationship between flow velocity and hydraulic gradient is observed.Water flow in clay can be divided into the pre-Darcy flow and Darcy flow regions by the critical hydraulic gradient,which is 10-12 for the Albic soil with dry density between 1.3 g/cm^(3)and 1.8 g/cm^(3).According to the disjoining pressure theory,immovable water due to water adsorption on the pore wall is the primary reason for water flow deviating from Darcy's law in clay.The results indicate that the percentage of movable water ranges from 39.7%to 59.3%for the six samples at a hydraulic gradient of 1.As the hydraulic gradient increases,the percentage of moveable water also increases.Additionally,there is a strong correlation between the percentage of movable water and the variation in hydraulic conductivity with the hydraulic gradient.Furthermore,a quantitative relationship between the percentage of movable water and the hydraulic conductivity has been established.The results of this study suggest that water adsorption on the pore wall not only affects the water movability,but is also closely related to the pre-Darcy flow phenomenon in clay.
基金2023 Hubei Provincial Key Laboratory Open Project-Nursing Special Project:2023KFH017Current Status Survey and Interventional Research on Alexithymia in Elderly Cancer Patients(Chaired by Lili Zhang)+3 种基金Wuhan University Clinical Nursing Special Research Cultivation Fund Project:LCHL202307Constructing a Long-Term Care Model Based on Narrative Transport Model to Identify and Reduce the Vulnerability of Psychological Crises in Elderly Patients with Comorbidities(Chaired by Lili Zhang)2022 Hubei Provincial Key Laboratory Open Project-Nursing Special Project:2022KFH030Empirical Study on the Construction and Application of a Frailty Risk Warning Model for Hospitalized Elderly Patients(Chaired by Jiaojiao Wu).
文摘Background:With the rapid aging of China’s population and the increasing prevalence of comorbidities in the elderly,psychological crises have become more common.This study aims to investigate the present status of psychological vulnerability,aging attitudes,and life meaning in elderly patients with comorbidities.Methods:A total of 685 elderly inpatients and outpatients at Renmin Hospital of Wuhan University between July and December 2022 were selected using the simple random sampling method.Social demographic data were collected,and the Attitudes to aging Questionnaire(AAQ),the Chinese Life Meaning Questionnaire(C-MLQ),and the Psychological Vulnerability Scale(C-PVS)were used for the analysis.A total of 685 questionnaires were received,and 602 valid questionnaires were collected,with an effective rate of 87.88%.Data analysis was performed using SPSS V25.0 and AMOS V24.0.Results:The total scores of psychological vulnerability,aging attitudes,and life meaning were 69.4±12.8,80.2±13.5 and 39.2±8.3,respectively.The psychological vulnerability was significantly negatively correlated with life meaning and aging attitudes(r=-0.351,-0.264;p<0.01).There was a significant positive correlation between aging attitudes and life meaning(r=0.515;p<0.01).Life meaning played a partial mediating role between psychological vulnerability and aging attitudes(β=3.070,p<0.05).Conclusion:This study found that the psychological vulnerability in elderly patients with comorbidities was at the lower level,which was related to the elderly patients’aging attitudes and their current status of life meaning.The level of psychological vulnerability in elderly patients with senile-related comorbidities needs to be further improved.Medical workers should pay attention to the psychological vulnerability of elderly patients and improve the identification of psychological crises of such patients.
基金2023 Annual Funded Projects for Educational Scientific Research at Xuzhou University of Technology“Construction and Practice of the Quality Assurance System for Education and Teaching in Applied Undergraduate Colleges under the Background of Digitalization”(YGJ2345)。
文摘This paper discusses the optimization strategy of education and teaching quality assurance systems in applied colleges and universities under the background of digital intelligence.It first summarizes the relevant theories of digital intelligence transformation and analyzes the impact of digital intelligence transformation on higher education.Secondly,this paper puts forward the principles of constructing the quality assurance system of applied colleges,including strengthening the quality assurance consciousness,improving teachers’digital literacy,and implementing digital intelligence governance.From the practical perspective,this paper expounds on strategies such as optimizing educational teaching resource allocation,constructing a diversified evaluation system of teaching quality,strengthening the construction and training of teaching staff,and innovating teaching management methods.Specific optimization measures are put forward,such as improving policies,regulations,and system guarantees,strengthening cooperation between schools and enterprises,integrating industry,school,and research,building an educational information platform,and improving the monitoring and feedback mechanism of educational quality.
基金supported by 2021 Construction project of key disciplines of Traditional Chinese Medicine(clinical)in Guangdong Province([2021]No.129)2020 Foshan City’s‘14th Five-Year’key specialized projects of traditional Chinese medicine(No.15).Foshan self-financing science and technology plan project(2320001009048).
文摘Background:The relationship between tea intake(TI)and sleep disorders(SDs)has been a topic of interest for some time,but there remains a lack of data showing a causal relationship.We aimed to use a two-sample Mendelian randomization study to determine whether there is a causal link between TI and SDs.Methods:We collected data regarding TI,with a focus on green tea intake(GTI),herbal tea intake(HTI),and rooibos tea intake(RTI);and data regarding SDs and insomnia from genome-wide association studies.We analyzed these data using an inverse variance-weighted two-sample Mendelian randomization study,by means of the TwoSampleMR package in R4.2.3 software.Results:We found no genetic causal relationships of TI,GTI,HTI,or RTI with insomnia.The odds ratios(ORs)for these relationships were as follows:TI:OR=0.61,95%confidence interval(CI):0.29–1.28;GTI:OR=1.04,95%CI:0.95–1.14;HTI:OR=0.98,95%CI:0.82–1.17;and RTI:OR=1.04,95%CI:0.99–1.09.In addition,there were no genetic causal relationships of TI,GTI,HTI,or RTI with SDs.The OR values for these relationships were as follows:TI:OR=0.6,95%CI:0.34–1.06;GTI:OR=1,95%CI:0.93–1.07;HTI:OR=0.89,95%CI:0.66–1.2;and RTI:OR=1.02,95%CI:0.98–1.06.Conclusion:We found no causal relationships of TI with SDs or insomnia,irrespective of the type of tea consumed.However,additional Mendelian randomization studies are required to further explore the relationships of the timing and quantity of tea consumption with SDs and insomnia.
基金supported by 2021 Construction project of key disciplines of Traditional Chinese Medicine(clinical)in Guangdong Province([2021]No.129)2020 Foshan City’s‘14th Five-Year’key specialized projects of traditional Chinese medicine(No.15).Foshan self-financing science and technology plan project(2320001009048).
文摘Background:Telemedicine refers to the use of information technology by medical institutions to directly provide diagnostic and therapeutic services to patients outside the healthcare facility.It encompasses various aspects such as remote diagnosis,remote monitoring,remote consultation,and remote outpatient services.Numerous articles have evaluated its role in controlling diseases like hypertension,diabetes,atrial fibrillation,and ischemic stroke.However,the existing literature exhibits varying quality and sample sizes,lacking robust convincing power and systematic effectiveness evaluation.Methods:Following The Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 guidelines,we identified articles on remote medical intervention in ischemic stroke through databases including Web of Science,PubMed,EMBASE,Cochrane Library,CNKI,Weipu,and Wanfang.The search spanned from the inception of the databases to June 30,2022.Two researchers independently assessed literature quality,extracted data,and conducted meta-analysis using RevMan 5.3 software.Results:Ten articles,involving 5092 patients,were included.Meta-analysis results indicate that telemedicine can effectively enhance compliance with doctors’advice in ischemic stroke patients.Telemedicine is also associated with reduced stroke recurrence,moderate to severe disability,systolic and diastolic blood pressure,National Institutes of Health Stroke Scale scores,and Modified Rankin Scale scores.Additionally,telemedicine demonstrates effectiveness in improving Fugl-Meyer motor function assessment and the Barthel Index of activity of daily living in ischemic stroke patients.However,telemedicine does not significantly reduce stroke hospitalization in the past year and the death rate.Conclusion:In comparison to traditional healthcare,telemedicine exhibits advantages in improving compliance and enhancing functionality in ischemic stroke patients.It is worth promoting telemedicine for better management of ischemic stroke patients.However,this study does not explain how telemedicine improves the functionality of ischemic stroke patients,indicating a need for further research.
基金co-supported by the National Natural Science Foundation of China (Nos. 51705426 and 51475379)the Key Research and Development Plan of Shaanxi Province of China (No. 2017GY-101)
文摘Carbon fiber reinforced plastic and titanium alloy(CFRP/Ti) stacks have been widely used as aerospace structures because of their excellent combination of physical properties. Interface damage caused by interface gaps, significantly different from that of metal/metal stacks, is a common problem in the through-hole drilling of CFRP/Ti stacks with low stiffness. In this study, a force–deformation coupling model was developed to further examine the formation mechanism and the control method of interface damage. Firstly, the coupling model was built considering the interaction between the thrust force and the deformation. To solve this model, a numerical method was proposed in which specific cutting coefficients were calibrated using only the thrust force of rigid stacks. Secondly, drilling experiments were performed with different feed rates and bending stiffness. Experimental results indicate that interface damage mainly includes interlayer chips and surface damage of CFRP layers. The surface damage, which is irreparable, is caused by the rotary extension of metal chips along the interlayer gap. Thirdly, variations of the interface gap were calculated with the coupling model that had been verified by measured thrust forces. The damage area was found to have a linear dependence relation with the interlayer gap. However, in conditions of large gap sizes, the interface damage areas increased with the interlayer gap at high feed rates, while decreasing slightly at low feed rates. This phenomenon was satisfactorily explained by the presented model. Finally, a method was proposed to determine the appropriate pressure exceeding which no interlayer damage will occur. Additional drilling experiments proved the method effective. This study leads to further understanding of the forming mechanism of interlayer damage and of selecting appropriate parameters in drilling low-stiffness composite/metal stacks.
基金financial support from the National Natural Science Foundation of China(81671737)the support from‘Sponsored by Shanghai Pujiang Program’(18PJD020)the Interdisciplinary Program of Shanghai Jiao Tong University(YG2019QNB31)。
文摘The rapid development of electric vehicles and mobile electronic devices is the main driving force to improve advanced high-performance lithium ion batteries(LIBs).The capacity,rate performance and cycle stability of LIBs rely directly on the electrode materials.As far as the development of the advanced LIBs electrode is concerned,the improvement of anode materials is more urgent than the cathode materials.Industrial production of anode materials superior to commercial graphite still faces some challenges.This review sets out the most basic LIBs anode material design.The reaction principles and structural design of carbon materials,various transition metal oxides,silicon and germanium are summarized,and then the progress of other anode materials are analyzed.Due to the rapid development of metal organic frameworks(MOFs)in energy storage and conversion in recent years,the synthesis process and energy storage mechanism of nanostructures derived from MOF precursors are also discussed.From the perspective of novel structural design,the progress of various MOFs-derived materials for alleviating the volume expansion of anode materials is discussed.Finally,challenges for the future development of advanced anode materials for LIBs will be considered.
基金financial support of Distinguished scholars of yueqi (NO. 800015Z1179)National Science Fund subsidized project (51474220)Basic scientific research project of the CPC Central Committee (NO. 2009QZ03)
文摘Using self-researched gas drainage borehole stability dynamic monitoring device, three-dimensional deformation characteristics of borehole under steady vertical load were researched experimentally and systematically. This research indicated that under the action of steady loading, the mechanical deformation path of the simulated gas drainage borehole is gradually complicated, and the decay of the borehole circumferential strain is an important characterization of the prediction and early warning of borehole instability and collapse. The horizontal position of borehole occurs compressive strain, and the vertical of which occurs tensile strain under the action of vertical stress. At the initial stage of loading, the vertical strain is more sensitive than that in the horizontal direction. After a certain period of time, the horizontal strain is gradually higher than the vertical one, and the intersection of the borehole horizontal diameter and the hole wall is the stress concentration point. With the increase of the depth of hole, the strain shows a gradual decay trend as a whole, and the vertical strain decays more observably, but there is no absolute position correlation between the amount of strain decay and the increase in borehole depth,and the area within 1.5 times the orifice size is the borehole stress concentration zone.
基金supported by National Natural Science Foundation of China(grant number 51975472)Intelligent Robotic in Ministry of Science and Technology of the People’s Republic of China(grant number 2017YFB1301703)Shaanxi New Star Plan of Science and Technology(grant number 2019KJXX-063)。
文摘A novel virtual material layer model based on the fractal theory was proposed to predict the natural frequencies of carbon fiber reinforced plastic composite bolted joints.Rough contact surfaces of composite bolted joints are modeled with this new proposed approach.Numerical and experimental modal analyses were conducted to validate the effectiveness of the proposed model.A good consistence is noted between the numerical and experimental results.To demonstrate the necessity of accurately modeling the rough contact surfaces in the prediction of natural frequencies,virtual material layer model was compared with the widely used traditional model based on the Master-Slave contact algorithm and experiments,respectively.Results show that the proposed model has a better agreement with experiments than the widely used traditional model(the prediction accuracy is raised by 8.77%when the pre-tightening torque is 0.5 N·m).Real contact area ratio A*of three different virtual material layers were calculated.Value of A*were discussed with dimensionless load P*,fractal dimension D and fractal roughness G.This work provides a new efficient way for accurately modeling the rough contact surfaces and predicting the natural frequencies of composite bolted joints,which can be used to help engineers in the dynamic design of composite materials.
