The reduced-activation ferritic/martensitic(RAFM)steel CLF-1 has been designed as a candidate structural material for nuclear fusion energy reactors.For engineering mechanical design,the effects of temperature on the ...The reduced-activation ferritic/martensitic(RAFM)steel CLF-1 has been designed as a candidate structural material for nuclear fusion energy reactors.For engineering mechanical design,the effects of temperature on the strain distribution of CLF-1 steel during uniaxial tensile tests were explored within the temperature range from room temperature to 650°C using uniaxial tensile tests combined with in situ digital image correlation analysis.Strain-concentrated regions alternately distributed±45°along the tensile direction could be attributed to the shear stress having the maximum value at±45°along the tensile direction and the coordinated deformation of the microstructure.The total strain distribution changed from a normal distribution to a lognormal distribution with increasing deformation owing to the competition between the elastic and plastic strains at all test temperatures.Strain localization has a strong relationship with temperature at the same engineering strain because of the temperature effects on dynamic strain aging(DSA).The stronger the DSA effect,the stronger the strain localization.With increasing temperature,the stronger the strain localization at the same strain,the weaker the plasticity,that is,DSA-induced embrittlement,and the slower the strength decline,that is,DSA-induced hardening.展开更多
The rapeseed,as the second oilseed crop in China,is an important source of edible oil.Reasonable planting density can improve rapeseed production efficiency,and indirectly increase farmers'the production enthusias...The rapeseed,as the second oilseed crop in China,is an important source of edible oil.Reasonable planting density can improve rapeseed production efficiency,and indirectly increase farmers'the production enthusiasm of planting rapeseed.To gain a more comprehensive understanding of the study on effect of rapeseed yield to planting density,this article reviews the effect on planting density to yield in rapeseed,including the influences of the interaction between cultivation factors(variety,sowing period,and fertilization),the impact of plant density to lodging resistance and growth and development(biological characteristics,agronomic characteristics,yield traits,and quality tracts),and planting density and the relationship between light and planting density,are reviewed.The lodging resistance of oilseed rape and population yield of different rape varieties can be improved by choosing the appropriate sowing date and fertilizer application,and give full play to the rational utilization of resources and the maximization of benefits.The oilseed rape can make rational use of light and nutrients,which is conducive to dry matter accumulation and yield improvement,with proper planting density.This review will provide a theoretical basis and practical support for rapeseed planting,management,and mechanized production.展开更多
Objective:To develop a rapid diagnostic kit for identifying snake venom types,aimed at providing a basis for clinical diagnosis and laying a foundation for early treatment through quick blood testing of injured patien...Objective:To develop a rapid diagnostic kit for identifying snake venom types,aimed at providing a basis for clinical diagnosis and laying a foundation for early treatment through quick blood testing of injured patients.Methods:Anti-snake venom immunoglobulin(IgG)was prepared,biotinylated specific IgG was screened,detection enzyme-labeled strips were produced,and rapid identification of snakebites was performed.Pre-experimental verification was conducted to establish standard curves and confirm specificity.The kit was tested on clinical samples and the results were analyzed.Repeatability and stability were evaluated through multiple repeated tests and experiments under different storage conditions.Finally,sensitivity and specificity were calculated,receiver operating characteristic curves(ROC curves)were drawn,and statistical analysis software was used for data analysis to ensure the reliability and effectiveness of the kit.Results:The test showed high sensitivity and specificity.Conclusion:The rapid diagnostic kit for identifying snake venom types in blood tests demonstrates high reliability and effectiveness in clinical diagnosis.展开更多
Weak interlayers play a crucial role in the seismic performance of bedding slopes;however,the effects of structural surface development within these layers remain underexplored.This study presents two scaled models of...Weak interlayers play a crucial role in the seismic performance of bedding slopes;however,the effects of structural surface development within these layers remain underexplored.This study presents two scaled models of bedding slopes,each with different weak interlayers:one with a homogeneous weak layer and another with discontinuous interfaces.Shaking table tests were conducted to compare their seismic performance.The results show that the peak ground acceleration(PGA)values above the weak interlayer in model A were significantly higher than those in model B,with the differences increasing as the input wave amplitude increased.The peak earth pressure(PEP)values at the tensile failure boundary at the rear edge of model A were also higher,whereas those within the weak layer at the toe of model A were lower than those in model B.Deformation analysis revealed that the maximum principal strain in model A initially appeared at the upper part of the tensile failure boundary,while the maximum shear strain was concentrated near the rear edge within the weak layer.In contrast,model B exhibited the opposite strain distribution.These findings provide insight into the impact of weak interlayers on the dynamic response and deformation of bedding slopes,highlighting the importance of considering this factor in seismic landslide investigations and failure mode predictions.展开更多
The seepage of groundwater and the strain-softening of rock mass in a submarine tunnel expand the plastic region of rock,thereby affecting its overall stability.It is therefore essential to study the stress and strain...The seepage of groundwater and the strain-softening of rock mass in a submarine tunnel expand the plastic region of rock,thereby affecting its overall stability.It is therefore essential to study the stress and strain fields in the rocks surrounding the submarine tunnel by considering the coupled effect of strainsoftening and seepage.However,the evolution equation for the hydro-mechanical parameters in the existing fully coupled solution is a uniform equation that is unable to reproduce the characteristics of rock mass in practice.In this study,an updated numerical procedure for the submarine tunnel is derived by coupling strain-softening and seepage effect based on the experimental results.According to the hydro-mechanical coupling theory,the hydro-mechanical parameters such as elastic modulus,Poisson's ratio,Biot's coefficient and permeability coefficient of rocks are characterized by the fitting equations derived from the experimental data.Then,the updated numerical procedure is deduced with the governing equations,boundary conditions,seepage equations and fitting equations.The updated numerical procedure is verified accurately compared with the previous analytical solution.By utilizing the updated numerical procedure,the characteristics of stress field and the influences of initial pore water pressure,Biot's coefficient,and permeability coefficient on the stress,displacement and water-inflow of the surrounding rocks are discussed.Regardless of the variations in hydro-mechanical parameters,the stress distribution has a similar trend.The initial permeability coefficient exerts the most significant influence on the stress field.With the increases in initial pore water pressure and Biot's coefficient,the plastic region expands,and the water-inflow and displacement increase accordingly.Given the fact that the stability of the tunnel is more sensitive to the seepage force controlled by the hydraulic parameters,it is suggested to dewater the ground above the submarine tunnel to control the initial pore water pressure.展开更多
Narrow backfill earth pressure estimation is applied to study the stability of supporting structures in the vicinity of existing buildings.Previous narrow backfill earth pressure studies have neglected seismic-unsatur...Narrow backfill earth pressure estimation is applied to study the stability of supporting structures in the vicinity of existing buildings.Previous narrow backfill earth pressure studies have neglected seismic-unsaturated seepage multi-field coupling,resulting in inaccurate estimates.To address these deficiencies,this paper proposed a calculation method for seismic passive earth pressure in unsaturated narrow backfill,based on inclined thin-layer units.It considers the interlayer shear stress,arching effect,and the multi-field coupling of seismic-unsaturated seepage.Additionally,this paper includes a parametric sensitivity analysis.The outcomes indicate that the earthquake passive ground pressure of unsaturated narrow backfill can be reduced by increasing the aspect ratio,seismic acceleration coefficient,and unsaturation parameterα.It can also be reduced by decreasing the effective interior friction angle,soil cohesion,wallearth friction angle,and vertical discharge.Furthermore,for any width soil,lowering the elevation of the action point of passive thrust can be attained by raising the effective interior friction angle,wall-earth friction angle,and unsaturation parameterα.Reducing soil cohesion,seismic acceleration coefficient,and vertical discharge can also lower the height of the application point of passive thrust.展开更多
The fracture behaviours and notch effects of single-edge-notched(SEN)and double-edge-notched(DEN)2D carbon fibre reinforced carbon matrix composites(C/Cs)were discussed and compared.The fracture behaviours of DEN and ...The fracture behaviours and notch effects of single-edge-notched(SEN)and double-edge-notched(DEN)2D carbon fibre reinforced carbon matrix composites(C/Cs)were discussed and compared.The fracture behaviours of DEN and SEN were performed by tensile and bending load-displacement relationships,and the effects of notch depth on notch sensitivity were determined by DEN specimens.The results from mechanical tests indicated that the SEN exhibited a brittle behaviour with linear elasticity,while the DEN exhibited a ductile behaviour with nonlinearity.It was also found that increasing notch depth and decreasing ligament width can lead to a higher ultimate tensile strength of DEN.On the other hand,the digital image correlation(DIC)method and acoustic emission(AE)system were also applied during the mechanical tests to study the local mechanical characteristics of shear damage,strain concentration and fracture behaviour of 2D C/Cs.The results revealed the mechanisms of notch insensitivity and explained the differences in fracture behaviours between SEN and DEN.展开更多
Several Trichoderma species serve as biocontrol agents in agriculture through their phytopathogen growth inhibition capabilities.However,the antagonistic mechanism of certain strains primarily operates through direct ...Several Trichoderma species serve as biocontrol agents in agriculture through their phytopathogen growth inhibition capabilities.However,the antagonistic mechanism of certain strains primarily operates through direct action.This study aims to explore an effective strain with comprehensive capabilities and elucidate its practical viability and action mechanism.Trichoderma gamsii strain TC959,exhibiting robust antagonistic and plant growth-promoting properties,was identified.The strain directly inhibits plant pathogen through the production of secondary metabolites,siderophores,and chitinase/xylanase,while promotes plant growth via indole-3-acetic acid/gibberellin release.Additionally,the strain activates induced systemic resistance by enhancing the chlorophyll a/b ratio and jasmonic acid content in pepper seedlings through root colonization,leading to elevated defense-related gene expression,antioxidant enzyme activity,and indole-3-acetic acid/gibberellin production.These mechanisms collectively enhance disease resistance and promote plant growth.Moreover,TC959 demonstrates superior resistance to oxidation and chemical fungicides,facilitating strain viability maintenance and ensuring healthy pepper seedling development.The study concludes that strain TC959 exhibits significant biocontrol potential and comprehensive functions against pepper damping-off disease,warranting further practical applications.展开更多
The seismic performance of a caisson structure under two types of models with a saturated sandy foundation(CSS)and an expanded polystyrene(EPS)composite soil foundation(CES)are studied using shaking table tests.The ma...The seismic performance of a caisson structure under two types of models with a saturated sandy foundation(CSS)and an expanded polystyrene(EPS)composite soil foundation(CES)are studied using shaking table tests.The macro phenomena of the two different foundation models are described and analyzed.The effects of the replacement of EPS composite soil on seismic-induced liquefaction of backfill and the dynamic performance of a caisson structure are evaluated in detail.The results show that the excess pore water pressure generation in the CES is significantly slower than that in the CSS during the shaking.The dynamic earth pressure acting on the caisson has a triangular shape.The response of horizontal acceleration,displacement,settlement,and rotation angle of the caisson in the CES is smaller than that in the CSS,which means the caisson in the CES has a better seismic performance.Furthermore,the out-of-phase phenomenon between dynamic earth thrust and inertial force in the CES is more obvious than that in the CSS,which is beneficial to reduce the lateral force and improve the stability of the caisson structure.展开更多
Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crac...Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.展开更多
Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the...Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.展开更多
The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmiss...The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms.These findings were discussed with the local strain measurements via digital image correlation.The results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of yielding.The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier effect.The volume fraction of RA gradually decreased from 26.8%to 8.2%prior to fracture.In the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.展开更多
Tartary buckwheat(Fagopyrum tataricum)is a well-known pseudocereal for its health and economic value.However,abundant antinutritional factors(ANFs)reduces its health benefits.As reported,germination can improve the nu...Tartary buckwheat(Fagopyrum tataricum)is a well-known pseudocereal for its health and economic value.However,abundant antinutritional factors(ANFs)reduces its health benefits.As reported,germination can improve the nutritional profile of grains.In this study,we systematically evaluate the safety of Tartary buckwheat seeds(TB)and Tartary buckwheat sprouts(TBS)used as high active ingredients.After evaluating nutrition levels,bioactive compounds and ANFs in TBS during germinating,5^(th)-day TBS were selected as the raw material.C57BL/6J mice were gavaged daily with distilled water,TB,or TBS for 6 weeks.The physiological indices related to ANFs were determined.Results showed that the TB intake tends to generate negative effects on the gut microbiota,and organs.Additionally,upon TB intake,the Fe^(3+)content in serum,trypsin activity in pancreas and jejunum decreased,while the cytokine,IgE,and histamine levels in serum,water content in faeces,cytokine levels in liver and jejunum increased.Conversely,TBS did not induce any obvious negative effects on the above relevant indices and showed better lipid-lowering effect.Altogether,TBS are safer and more effective as a raw material to produce the functional food for long-term consumption with the intention of preventing and treating hyperlipidaemia.展开更多
The flexoelectric effect refers to the electromechanical coupling between electric polarization and mechanical strain gradient.It universally exists in a variety of materials in any space group,such as liquid crystals...The flexoelectric effect refers to the electromechanical coupling between electric polarization and mechanical strain gradient.It universally exists in a variety of materials in any space group,such as liquid crystals,dielectrics,biological materials,and semiconductors.Because of its unique size effect,nanoscale flexoelectricity has shown novel phenomena and promising applications in electronics,optronics,mechatronics,and photovoltaics.In this review,we provide a succinct report on the discovery and development of the flexoelectric effect,focusing on flexoelectric materials and related applications.Finally,we discuss recent flexoelectric research progress and still‐unsolved problems.展开更多
Liver cancer is the fourth cause of cancer-related deaths and the primary cause of death in patients with compensated cirrhosis.In recent years,the role of traditional Chinese medicine in the treatment of liver cancer...Liver cancer is the fourth cause of cancer-related deaths and the primary cause of death in patients with compensated cirrhosis.In recent years,the role of traditional Chinese medicine in the treatment of liver cancer has attracted more and more attention and recognition.Luteolin(LUT)and glycyrrhetinic(GA)are natural compounds extracted from Chinese herbal medicine.LUT exhibits various biological activity including anti-inflammatory,antibacterial,antiviral,anti-tumor,and neuroprotective effects.GA significantly inhibits the growth and metastasis of cancer cells.However,the low water solubility of both compounds hinders their clinical applications.In this study,rod-shaped nanoparticles(NPs)self-assembled from LUT and GA were designed to enhance drug solubility and tumor-targeting capability.We verified that the assembly mechanism of the NPs was π-π stacking.These NPs significantly inhibited the proliferation of liver cancer cells while had no significant effect on normal liver cells.In a mouse model of liver cancer,these NPs demonstrated superior tumor-targeting ability due to the enhanced permeability and retention effect,and the affinity of GA for liver cancer cells,resulting in better therapeutic efficacy with lower systemic toxicity.Results of network pharmacology analysis showed that LUT and GA respectively targeted estrogen receptor 1(ESR1)protein and cyclin-dependent kinase 1(CDK1)protein to corporately induce tumor cell cycle arrest,which induced the inhibition of tumor cell proliferation.In conclusion,this study provides a novel reference for the treatment of liver cancer.展开更多
The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is great...The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is greater than that under creep conditions,indicating that the dynamic stress field significantly influences the rheological behaviours of sandstone.Following the rheological tests,the number of small pores in the sandstone decreased,while the number of medium-sized pores increased,forming new seepage channels.The high initial rheological stress accelerated fracture compression and the closure of seepage channels,resulting in reduction in the permeability of sandstone.Based on the principles of generalized rheology and the experimental findings,a novel rock rheological constitutive model incorporating both the dynamic stress field and seepage properties has been developed.Numerical simulations of surrounding rock deformation in geotechnical engineering were carried out using a secondary development version of this model,which confirmed the applicability of the generalized rheological numerical simulation method.These results provide theoretical support for the long-term stability evaluation of engineering rock masses and for predicting the deformation of surrounding rock.展开更多
Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest managemen...Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.展开更多
Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P...Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P fractions is potentially an adaptive strategy for plants to cope with soil N(P)availability and nutrient-limiting conditions.However,the impact of the interactions between imbalanced anthropogenic N and P inputs on the concentrations and allocation proportions of leaf P fractions in forest woody plants remains elusive.We conducted a metaanalysis of data about the concentrations and allocation proportions of leaf P fractions,specifically associated with individual and combined additions of N and P in evergreen forests,the dominant vegetation type in southern China where the primary productivity is usually considered limited by P.This assessment allowed us to quantitatively evaluate the effects of N and P additions alone and interactively on leaf P allocation and use strategies.Nitrogen addition(exacerbating P limitation)reduced the concentrations of leaf total P and different leaf P fractions.Nitrogen addition reduced the allocation to leaf metabolic P but increased the allocation to other fractions,while P addition showed opposite trends.The simultaneous additions of N and P showed an antagonistic(mutual suppression)effect on the concentrations of leaf P fractions,but an additive(summary)effect on the allocation proportions of leaf P fractions.These results highlight the importance of strategies of leaf P fraction allocation in forest plants under changes in environmental nutrient availability.Importantly,our study identified critical interactions associated with combined N and P inputs that affect leaf P fractions,thus aiding in predicting plant acclimation strategies in the context of intensifying and imbalanced anthropogenic nutrient inputs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12175231 and 11805131)Anhui Natural Science Foundation of China(No.2108085J05)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP009)。
文摘The reduced-activation ferritic/martensitic(RAFM)steel CLF-1 has been designed as a candidate structural material for nuclear fusion energy reactors.For engineering mechanical design,the effects of temperature on the strain distribution of CLF-1 steel during uniaxial tensile tests were explored within the temperature range from room temperature to 650°C using uniaxial tensile tests combined with in situ digital image correlation analysis.Strain-concentrated regions alternately distributed±45°along the tensile direction could be attributed to the shear stress having the maximum value at±45°along the tensile direction and the coordinated deformation of the microstructure.The total strain distribution changed from a normal distribution to a lognormal distribution with increasing deformation owing to the competition between the elastic and plastic strains at all test temperatures.Strain localization has a strong relationship with temperature at the same engineering strain because of the temperature effects on dynamic strain aging(DSA).The stronger the DSA effect,the stronger the strain localization.With increasing temperature,the stronger the strain localization at the same strain,the weaker the plasticity,that is,DSA-induced embrittlement,and the slower the strength decline,that is,DSA-induced hardening.
基金Supported by Analysis on Oil Synthesis Process of NAPA Rapeseed by cDNA-AFLP and Proteomics(2018J01713).
文摘The rapeseed,as the second oilseed crop in China,is an important source of edible oil.Reasonable planting density can improve rapeseed production efficiency,and indirectly increase farmers'the production enthusiasm of planting rapeseed.To gain a more comprehensive understanding of the study on effect of rapeseed yield to planting density,this article reviews the effect on planting density to yield in rapeseed,including the influences of the interaction between cultivation factors(variety,sowing period,and fertilization),the impact of plant density to lodging resistance and growth and development(biological characteristics,agronomic characteristics,yield traits,and quality tracts),and planting density and the relationship between light and planting density,are reviewed.The lodging resistance of oilseed rape and population yield of different rape varieties can be improved by choosing the appropriate sowing date and fertilizer application,and give full play to the rational utilization of resources and the maximization of benefits.The oilseed rape can make rational use of light and nutrients,which is conducive to dry matter accumulation and yield improvement,with proper planting density.This review will provide a theoretical basis and practical support for rapeseed planting,management,and mechanized production.
基金Rapid Identification and Analysis of Snake Venom Types in Snakebites in Renshou County,(Project No.:2024KJZD072)。
文摘Objective:To develop a rapid diagnostic kit for identifying snake venom types,aimed at providing a basis for clinical diagnosis and laying a foundation for early treatment through quick blood testing of injured patients.Methods:Anti-snake venom immunoglobulin(IgG)was prepared,biotinylated specific IgG was screened,detection enzyme-labeled strips were produced,and rapid identification of snakebites was performed.Pre-experimental verification was conducted to establish standard curves and confirm specificity.The kit was tested on clinical samples and the results were analyzed.Repeatability and stability were evaluated through multiple repeated tests and experiments under different storage conditions.Finally,sensitivity and specificity were calculated,receiver operating characteristic curves(ROC curves)were drawn,and statistical analysis software was used for data analysis to ensure the reliability and effectiveness of the kit.Results:The test showed high sensitivity and specificity.Conclusion:The rapid diagnostic kit for identifying snake venom types in blood tests demonstrates high reliability and effectiveness in clinical diagnosis.
基金funding support from the National Nature Science Foundation of China(Grant No.41931296)the Open Research Project of Sichuan Provincial Key Laboratory for Major Hazard Source Monitoring and Control(Grant No.KFKT2023-4)the 57#Project(Grant No.JH2024015).
文摘Weak interlayers play a crucial role in the seismic performance of bedding slopes;however,the effects of structural surface development within these layers remain underexplored.This study presents two scaled models of bedding slopes,each with different weak interlayers:one with a homogeneous weak layer and another with discontinuous interfaces.Shaking table tests were conducted to compare their seismic performance.The results show that the peak ground acceleration(PGA)values above the weak interlayer in model A were significantly higher than those in model B,with the differences increasing as the input wave amplitude increased.The peak earth pressure(PEP)values at the tensile failure boundary at the rear edge of model A were also higher,whereas those within the weak layer at the toe of model A were lower than those in model B.Deformation analysis revealed that the maximum principal strain in model A initially appeared at the upper part of the tensile failure boundary,while the maximum shear strain was concentrated near the rear edge within the weak layer.In contrast,model B exhibited the opposite strain distribution.These findings provide insight into the impact of weak interlayers on the dynamic response and deformation of bedding slopes,highlighting the importance of considering this factor in seismic landslide investigations and failure mode predictions.
基金supported by the National Natural Science Foundation of China(Grant Nos.52279118 and U21A20159)Sub-project of National Key Research and Development(Grant No.2023YFC3007403).
文摘The seepage of groundwater and the strain-softening of rock mass in a submarine tunnel expand the plastic region of rock,thereby affecting its overall stability.It is therefore essential to study the stress and strain fields in the rocks surrounding the submarine tunnel by considering the coupled effect of strainsoftening and seepage.However,the evolution equation for the hydro-mechanical parameters in the existing fully coupled solution is a uniform equation that is unable to reproduce the characteristics of rock mass in practice.In this study,an updated numerical procedure for the submarine tunnel is derived by coupling strain-softening and seepage effect based on the experimental results.According to the hydro-mechanical coupling theory,the hydro-mechanical parameters such as elastic modulus,Poisson's ratio,Biot's coefficient and permeability coefficient of rocks are characterized by the fitting equations derived from the experimental data.Then,the updated numerical procedure is deduced with the governing equations,boundary conditions,seepage equations and fitting equations.The updated numerical procedure is verified accurately compared with the previous analytical solution.By utilizing the updated numerical procedure,the characteristics of stress field and the influences of initial pore water pressure,Biot's coefficient,and permeability coefficient on the stress,displacement and water-inflow of the surrounding rocks are discussed.Regardless of the variations in hydro-mechanical parameters,the stress distribution has a similar trend.The initial permeability coefficient exerts the most significant influence on the stress field.With the increases in initial pore water pressure and Biot's coefficient,the plastic region expands,and the water-inflow and displacement increase accordingly.Given the fact that the stability of the tunnel is more sensitive to the seepage force controlled by the hydraulic parameters,it is suggested to dewater the ground above the submarine tunnel to control the initial pore water pressure.
基金Project(42277175)supported by the National Natural Science Foundation of ChinaProject(NRMSSHR-2022-Z08)supported by the Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region,Ministry of Natural Resources,China。
文摘Narrow backfill earth pressure estimation is applied to study the stability of supporting structures in the vicinity of existing buildings.Previous narrow backfill earth pressure studies have neglected seismic-unsaturated seepage multi-field coupling,resulting in inaccurate estimates.To address these deficiencies,this paper proposed a calculation method for seismic passive earth pressure in unsaturated narrow backfill,based on inclined thin-layer units.It considers the interlayer shear stress,arching effect,and the multi-field coupling of seismic-unsaturated seepage.Additionally,this paper includes a parametric sensitivity analysis.The outcomes indicate that the earthquake passive ground pressure of unsaturated narrow backfill can be reduced by increasing the aspect ratio,seismic acceleration coefficient,and unsaturation parameterα.It can also be reduced by decreasing the effective interior friction angle,soil cohesion,wallearth friction angle,and vertical discharge.Furthermore,for any width soil,lowering the elevation of the action point of passive thrust can be attained by raising the effective interior friction angle,wall-earth friction angle,and unsaturation parameterα.Reducing soil cohesion,seismic acceleration coefficient,and vertical discharge can also lower the height of the application point of passive thrust.
基金Funded by the National Natural Science Foundation of China(Nos.52072356 and 52032011)。
文摘The fracture behaviours and notch effects of single-edge-notched(SEN)and double-edge-notched(DEN)2D carbon fibre reinforced carbon matrix composites(C/Cs)were discussed and compared.The fracture behaviours of DEN and SEN were performed by tensile and bending load-displacement relationships,and the effects of notch depth on notch sensitivity were determined by DEN specimens.The results from mechanical tests indicated that the SEN exhibited a brittle behaviour with linear elasticity,while the DEN exhibited a ductile behaviour with nonlinearity.It was also found that increasing notch depth and decreasing ligament width can lead to a higher ultimate tensile strength of DEN.On the other hand,the digital image correlation(DIC)method and acoustic emission(AE)system were also applied during the mechanical tests to study the local mechanical characteristics of shear damage,strain concentration and fracture behaviour of 2D C/Cs.The results revealed the mechanisms of notch insensitivity and explained the differences in fracture behaviours between SEN and DEN.
基金supported by the National Key Research and Development Program of China(2022YFC2303000).
文摘Several Trichoderma species serve as biocontrol agents in agriculture through their phytopathogen growth inhibition capabilities.However,the antagonistic mechanism of certain strains primarily operates through direct action.This study aims to explore an effective strain with comprehensive capabilities and elucidate its practical viability and action mechanism.Trichoderma gamsii strain TC959,exhibiting robust antagonistic and plant growth-promoting properties,was identified.The strain directly inhibits plant pathogen through the production of secondary metabolites,siderophores,and chitinase/xylanase,while promotes plant growth via indole-3-acetic acid/gibberellin release.Additionally,the strain activates induced systemic resistance by enhancing the chlorophyll a/b ratio and jasmonic acid content in pepper seedlings through root colonization,leading to elevated defense-related gene expression,antioxidant enzyme activity,and indole-3-acetic acid/gibberellin production.These mechanisms collectively enhance disease resistance and promote plant growth.Moreover,TC959 demonstrates superior resistance to oxidation and chemical fungicides,facilitating strain viability maintenance and ensuring healthy pepper seedling development.The study concludes that strain TC959 exhibits significant biocontrol potential and comprehensive functions against pepper damping-off disease,warranting further practical applications.
基金National Natural Science Foundation of China under Grant Nos. 52178336 and 52108324Natural Science Research Project of Colleges and Universities in Jiangsu Province of China under Grant No. 18KJA560002+1 种基金the Middle-Aged&Young Science Leaders of Qinglan Project of Universities in Jiangsu Province of ChinaPostgraduate Research&Practice Innovation Program in Jiangsu Province of China under Grant No. KYCX24_1585
文摘The seismic performance of a caisson structure under two types of models with a saturated sandy foundation(CSS)and an expanded polystyrene(EPS)composite soil foundation(CES)are studied using shaking table tests.The macro phenomena of the two different foundation models are described and analyzed.The effects of the replacement of EPS composite soil on seismic-induced liquefaction of backfill and the dynamic performance of a caisson structure are evaluated in detail.The results show that the excess pore water pressure generation in the CES is significantly slower than that in the CSS during the shaking.The dynamic earth pressure acting on the caisson has a triangular shape.The response of horizontal acceleration,displacement,settlement,and rotation angle of the caisson in the CES is smaller than that in the CSS,which means the caisson in the CES has a better seismic performance.Furthermore,the out-of-phase phenomenon between dynamic earth thrust and inertial force in the CES is more obvious than that in the CSS,which is beneficial to reduce the lateral force and improve the stability of the caisson structure.
基金funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan(Grant No.AP19680589).
文摘Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.
基金the financial support from the Fujian Science Foundation for Outstanding Youth(2023J06039)the National Natural Science Foundation of China(Grant No.41977259,U2005205,41972268)the Independent Research Project of Technology Innovation Center for Monitoring and Restoration Engineering of Ecological Fragile Zone in Southeast China(KY-090000-04-2022-019)。
文摘Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.
基金supported by the National Key R&D Program of China(No.2017YFB0304402)。
文摘The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms.These findings were discussed with the local strain measurements via digital image correlation.The results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of yielding.The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier effect.The volume fraction of RA gradually decreased from 26.8%to 8.2%prior to fracture.In the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.
基金Supported by the Opening Project of Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural AffairsSichuan Engineering and Technology Research Center of Coarse Cereal Industralization,Chengdu University(2022CC013)。
文摘Tartary buckwheat(Fagopyrum tataricum)is a well-known pseudocereal for its health and economic value.However,abundant antinutritional factors(ANFs)reduces its health benefits.As reported,germination can improve the nutritional profile of grains.In this study,we systematically evaluate the safety of Tartary buckwheat seeds(TB)and Tartary buckwheat sprouts(TBS)used as high active ingredients.After evaluating nutrition levels,bioactive compounds and ANFs in TBS during germinating,5^(th)-day TBS were selected as the raw material.C57BL/6J mice were gavaged daily with distilled water,TB,or TBS for 6 weeks.The physiological indices related to ANFs were determined.Results showed that the TB intake tends to generate negative effects on the gut microbiota,and organs.Additionally,upon TB intake,the Fe^(3+)content in serum,trypsin activity in pancreas and jejunum decreased,while the cytokine,IgE,and histamine levels in serum,water content in faeces,cytokine levels in liver and jejunum increased.Conversely,TBS did not induce any obvious negative effects on the above relevant indices and showed better lipid-lowering effect.Altogether,TBS are safer and more effective as a raw material to produce the functional food for long-term consumption with the intention of preventing and treating hyperlipidaemia.
基金support of the National Natural Science Foundation of China(Grant Nos.52192611,51872031,61904013,and 62405157)China Postdoctoral Science Foundation(Nos.2023M741890 and GZC20231215)the Fundamental Research Funds for the Central Universities.
文摘The flexoelectric effect refers to the electromechanical coupling between electric polarization and mechanical strain gradient.It universally exists in a variety of materials in any space group,such as liquid crystals,dielectrics,biological materials,and semiconductors.Because of its unique size effect,nanoscale flexoelectricity has shown novel phenomena and promising applications in electronics,optronics,mechatronics,and photovoltaics.In this review,we provide a succinct report on the discovery and development of the flexoelectric effect,focusing on flexoelectric materials and related applications.Finally,we discuss recent flexoelectric research progress and still‐unsolved problems.
基金the financial support from Henan Province Natural Science Foundation(No.252300420583)Henan Provincial Science and Technology Research Project(Nos.242102310455,242102310473,242102310517)the Key Project of Science and Technology Research funded by the Henan Provincial Department of Education(No.24A350002)。
文摘Liver cancer is the fourth cause of cancer-related deaths and the primary cause of death in patients with compensated cirrhosis.In recent years,the role of traditional Chinese medicine in the treatment of liver cancer has attracted more and more attention and recognition.Luteolin(LUT)and glycyrrhetinic(GA)are natural compounds extracted from Chinese herbal medicine.LUT exhibits various biological activity including anti-inflammatory,antibacterial,antiviral,anti-tumor,and neuroprotective effects.GA significantly inhibits the growth and metastasis of cancer cells.However,the low water solubility of both compounds hinders their clinical applications.In this study,rod-shaped nanoparticles(NPs)self-assembled from LUT and GA were designed to enhance drug solubility and tumor-targeting capability.We verified that the assembly mechanism of the NPs was π-π stacking.These NPs significantly inhibited the proliferation of liver cancer cells while had no significant effect on normal liver cells.In a mouse model of liver cancer,these NPs demonstrated superior tumor-targeting ability due to the enhanced permeability and retention effect,and the affinity of GA for liver cancer cells,resulting in better therapeutic efficacy with lower systemic toxicity.Results of network pharmacology analysis showed that LUT and GA respectively targeted estrogen receptor 1(ESR1)protein and cyclin-dependent kinase 1(CDK1)protein to corporately induce tumor cell cycle arrest,which induced the inhibition of tumor cell proliferation.In conclusion,this study provides a novel reference for the treatment of liver cancer.
基金supported and financed by Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology (No.2024yjrc96)Anhui Provincial University Excellent Research and Innovation Team Support Project (No.2022AH010053)+2 种基金National Key Research and Development Program of China (Nos.2023YFC2907602 and 2022YFF1303302)Anhui Provincial Major Science and Technology Project (No.202203a07020011)Open Foundation of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining (No.EC2023020)。
文摘The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is greater than that under creep conditions,indicating that the dynamic stress field significantly influences the rheological behaviours of sandstone.Following the rheological tests,the number of small pores in the sandstone decreased,while the number of medium-sized pores increased,forming new seepage channels.The high initial rheological stress accelerated fracture compression and the closure of seepage channels,resulting in reduction in the permeability of sandstone.Based on the principles of generalized rheology and the experimental findings,a novel rock rheological constitutive model incorporating both the dynamic stress field and seepage properties has been developed.Numerical simulations of surrounding rock deformation in geotechnical engineering were carried out using a secondary development version of this model,which confirmed the applicability of the generalized rheological numerical simulation method.These results provide theoretical support for the long-term stability evaluation of engineering rock masses and for predicting the deformation of surrounding rock.
文摘Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.
基金supported by the National Natural Science Foundation of China(No.41473068)supported by China Postdoctoral Science Foundation(No.2022M722667)。
文摘Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P fractions is potentially an adaptive strategy for plants to cope with soil N(P)availability and nutrient-limiting conditions.However,the impact of the interactions between imbalanced anthropogenic N and P inputs on the concentrations and allocation proportions of leaf P fractions in forest woody plants remains elusive.We conducted a metaanalysis of data about the concentrations and allocation proportions of leaf P fractions,specifically associated with individual and combined additions of N and P in evergreen forests,the dominant vegetation type in southern China where the primary productivity is usually considered limited by P.This assessment allowed us to quantitatively evaluate the effects of N and P additions alone and interactively on leaf P allocation and use strategies.Nitrogen addition(exacerbating P limitation)reduced the concentrations of leaf total P and different leaf P fractions.Nitrogen addition reduced the allocation to leaf metabolic P but increased the allocation to other fractions,while P addition showed opposite trends.The simultaneous additions of N and P showed an antagonistic(mutual suppression)effect on the concentrations of leaf P fractions,but an additive(summary)effect on the allocation proportions of leaf P fractions.These results highlight the importance of strategies of leaf P fraction allocation in forest plants under changes in environmental nutrient availability.Importantly,our study identified critical interactions associated with combined N and P inputs that affect leaf P fractions,thus aiding in predicting plant acclimation strategies in the context of intensifying and imbalanced anthropogenic nutrient inputs.
