An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of t...An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic algorithm.After validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine Vumat.By comparing the simulated results with the experimental results,the application of the ISV model was proven to be reliable.Meanwhile,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture strengthening.Besides,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.展开更多
The authors(Cai et al.,2022)claim that their proposed machine learning(ML)models,which are based on three typical ML algorithms and are trained to predict the burst capacity of pitting corroded pipelines,perform bette...The authors(Cai et al.,2022)claim that their proposed machine learning(ML)models,which are based on three typical ML algorithms and are trained to predict the burst capacity of pitting corroded pipelines,perform better than the existing semi-empirical formulas recommended by the international engineering code developers,DNV and ASME.The authors’assessments of the semi-empiri‐cal burst capacity formulas in Figure 10(a)and Table 8(Cai et al.,2022)incorrectly indicate that DNVGL-RP F101,ASME B31G,and modified ASME B31G are dan‐gerously unsafe due to significantly overestimating burst pressures in several cases.In contrast to the results and conclusions in Cai et al.展开更多
Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with ...Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with HMMH who were admitted to the hospital from June 2019 to June 2024 were selected.The minimum diameter of the macular hole(MH)in all patients was≤500μm.The patients were randomly divided into two groups.The experimental group received 25G pars plana vitrectomy(PPV)combined with ILM flipping and covering technique,while the reference group received PPV combined with ILM peeling.The efficacy indicators and best corrected visual acuity levels were compared between the two groups.Results:The MH closure rate and retinal reattachment rate were higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The best corrected visual acuity level was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The Chinese version of the Visual Function-Related Quality of Life Questionnaire-25(CVRQOL-25)score was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).No serious complications were observed in both groups postoperatively,and there was no difference between the two groups(P>0.05).Conclusion:The ILM flipping and covering technique can improve the MH closure rate and retinal reattachment rate in patients with HMMH(diameter≤500μm),enhance the best corrected visual acuity level,and improve the quality of life related to visual function,with fewer postoperative complications.展开更多
Developing an efficient photocatalyst is the key to realize the practical application of photocatalysis.The S-scheme heterojunction has great potential in photocatalysis due to its unique charge-carrier migration path...Developing an efficient photocatalyst is the key to realize the practical application of photocatalysis.The S-scheme heterojunction has great potential in photocatalysis due to its unique charge-carrier migration pathway,effective light absorption and high redox capacity.However,further enhancing the built-in electric field of the S-scheme,accelerating carrier separation,and achieving higher photocatalytic performance remain unresolved challenges.Herein,based on the continuously adjustable band structure of continuous solid-solution,a novel 0D/2D all solid-solution S-scheme heterojunction with adjustable internal electric field was designed and fabricated by employing a solid-solution of ZnxCd_(1–x)S and Bi_(2)MoyW_(1–y)O_(6)respectively as reduction and oxidation semiconductors.The synergistic optimization of effective light absorption,fast photogenerated carrier separation,and high redox potential leads can be tuned to promote photocatalytic activity.Under visible light,the S-scheme system constructed by Zn_(0.4)Cd_(0.6)S quantum dot(QDs)and Bi_(2)Mo_(0.2)W_(0.8)O_(6)monolayer exhibits a high rate for photocatalytic degradation C_(2)H_(4)(150.6×10^(–3)min^(–1)),which is 16.5 times higher than that of pure Zn_(0.4)Cd_(0.6)S(9.1×10^(–3)min^(–1))and 53.8 times higher than pure Bi_(2)Mo_(0.2)W_(0.8)O_(6)(2.8×10^(–3)min^(–1)).Due to the unique charge-carrier migration pathway,photo-corrosion of Zn_(x)Cd_(1–x)S is further inhibited simultaneously.In-situ irradiation X-ray photoelectron spectroscopy,photoluminescence spectroscopy,time-resolved photoluminescence,transient absorption spectroscopy and electron paramagnetic resonance provide compelling evidence for interfacial charge transfer via S-scheme pathways,while in-situ diffuse reflectance infrared Fourier transform spectroscopy identifies the reaction pathway for C_(2)H_(4)degradation.This novel S-scheme photocatalysts demonstrates excellent performance and potential for the practical application of the fruits and vegetables preservation at room temperatures.展开更多
Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,prov...Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,providing a wide variety of corresponding linear carboxylic esters bearing various functional groups in good yields and>20:1 linear/branch ratios.The reaction is optionally simple and does not need to use CO gas and acid co-catalysts.展开更多
Migration is a complex demographic phenomenon.Its dynamics can be explained by several factors whose spatial and temporal evolution is not easy to control.That is why this article aims to understand the factors of mig...Migration is a complex demographic phenomenon.Its dynamics can be explained by several factors whose spatial and temporal evolution is not easy to control.That is why this article aims to understand the factors of migration from a spatiotemporal perspective to fill the gaps in the literature.The aim of this article is to analyse the spatiotemporal dynamics of internal migration factors to deduce the zones of origin and destination in Burkina Faso.To do this,several types of data were used.These included secondary,spatial,statistical and survey data.The results of this study show that the influence of internal migration factors is uneven.The spatial distribution of internal migration factors follows a north-south gradient,with favourable conditions in the south.In fact,the northern part is characterised by a large population exodus,with around 42.6%of outgoing internal migrants,and the southern part by a large population influx.This southern part of the country receives around 34.6%of internal migrants.The areas from which migrants depart have unfavourable climatic,environmental,or socio-economic conditions,whereas the areas to which migrants migrate are characterised by favourable conditions for these factors.展开更多
We use a high-resolution numerical simulation to analyze the generation and evolution of semidiurnal internal tides in the Weddell-Scotia Confluence.Our results indicate that two ridges near the Antarctic Peninsula,th...We use a high-resolution numerical simulation to analyze the generation and evolution of semidiurnal internal tides in the Weddell-Scotia Confluence.Our results indicate that two ridges near the Antarctic Peninsula,the South Scotia Ridge(SSR)and the Philip Ridge(PR),are energetic sources of semidiurnal internal tides.The strongest semidiurnal barotropic to baroclinic energy conversion occurs around the crest of the SSR,reaching 0.3 W/m^(2).The depthintegrated,tidally averaged semidiurnal internal tide energy fluxes that radiated from the SSR reach about 2 kW/m.The northward semidiurnal internal tide energy fluxes entering the Scotia Sea are stronger than the southward energy fluxes entering the Powell Basin.For the SSR region between the South Orkney Plateau and Elephant Island,the areaintegrated barotropic to baroclinic conversion rate is 0.71 GW,of which 0.56 GW(79%)dissipates locally.The dissipation of internal tides occurs mainly in water depths of less than 1000 m.The dissipation rate over the SSR is as high as 10−7 W/kg.The energy fluxes create an anticlockwise gyre between the SSR and PR.The horizontal kinetic energy and available potential energy oscillate sinusoidally with peaks occurring at quarter-wavelength intervals.This energy pattern suggests the formation of standing waves due to interference between the semidiurnal internal tides originating from the SSR and PR.The results of this study show that internal tides and related mixing need to be considered in the analysis of water mass transformation in the Southern Ocean.展开更多
The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas holdup.Firstly,ga...The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas holdup.Firstly,gas holdup measurement method is improved by conducting multi-point liquid level measurement and using net fluid volume instead of bed volume to calculate gas holdup.Then,a stable conductivity method for liquid macromixing has been established by shielding large bubbles using#16nylon mesh.Subsequently,the influences of internal coverage(=12.6%,18.9% and 25.1%) on macroscopic fluid dynamics in a bubble column with a free wall area are systematically investigated.It is found that the presence of internals has a notable effect on macroscopic fluid dynamics.The overall gas holdup and gas-liquid volumetric mass transfer coefficient decrease,and the macromixing time decreases with the increase of internal cross-sectional area coverage.These are mainly caused by the uneven distribution of airflow due to the low resistance in the free wall area.This design makes maintenance easier,but in reality,the reactor performance has decreased.Further improvements will be made to the reactor performance based on such a configuration through flow guidance using baffles.展开更多
Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geo...Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geostrophic flows,respectively.Ocean current is composed of multiple flows;thus,internal tides and lee waves occur concurrently in the real ocean.In this paper,the Massachusetts Institute of Technology general circulation model(MITgcm)is used to conduct 2D numerical experiments.By varying background flow intensities,the energy and dissipation relationship between internal tides and lee waves are investigated.The results reveal that the internal tide beams become asymmetric due to the influence of Doppler shift.The lee wave structure gradually leads the wave field when the background flow velocity rises constantly.The presence of a background flow increases the energy portion of the high-mode wave by up to 15%-20%.Moreover,strong shear,owing to the background flow,considerably increases dissipation.When the background flow velocity is higher than the barotropic tidal current velocity,the isopycnal overturn triggered by the lee wave generates a dissipation of the same order of magnitude as the shear.展开更多
In the Arctic Ocean,turbulent mixing drives vertical heat flux,thereby affecting the sea ice variability.Internal wave is regarded as one of the important energy sources of mixing in this region.The high latitude and ...In the Arctic Ocean,turbulent mixing drives vertical heat flux,thereby affecting the sea ice variability.Internal wave is regarded as one of the important energy sources of mixing in this region.The high latitude and sea ice cover make internal wave in the Arctic Ocean apparently differs from that in mid-and low-latitude oceans.However,the internal wave and its underlying mechanism are less understood due to the lack of observations.This paper briefly reviews the recent studies and unresolved questions on the internal wave in the Arctic Ocean,including wind-driven near-inertial wave,internal tide,and high-frequency internal wave.The aim is to provide new insights for in-depth research in the future,with a focus on the mechanisms responsible for the evolution of internal wave under the rapidly changing Arctic climate.展开更多
Periodic isolator is well known for its wave filtering characteristic.While in middle and high frequencies,the internal resonances of the periodic isolator are evident especially when damping is small.This study propo...Periodic isolator is well known for its wave filtering characteristic.While in middle and high frequencies,the internal resonances of the periodic isolator are evident especially when damping is small.This study proposes a novel aperiodic vibration isolation for improving the internal resonances control of the periodic isolator.The mechanism of the internal resonances control by the aperiodic isolator is firstly explained.For comparing the internal resonances suppression effect of the aperiodic isolator with the periodic isolator,a dynamic model combing the rigid machine,the isolator,and the flexible plate is derived through multi subsystem modeling method and transfer matrix method,whose accuracy is verified through the finite element method.The influences of the aperiodicity and damping of the isolator on the vibration isolation performance and internal resonances suppression effect are investigated by numerical analysis.The numerical results demonstrate that vibration attenuation performances of the periodic isolator and aperiodic isolator are greatly over than that of the continuous isolator in middle and high frequencies.The aperiodic isolator opens the stop bandgaps comparing with the periodic isolator where the pass bandgaps are periodically existed.The damping of the isolator has the stop bandgap widening effect on both the periodic isolator and the aperiodic isolator.In addition,a parameter optimization algorithm of the aperiodic isolator is presented for improving the internal resonances control effect.It is shown that the vibration peaks within the target frequency band of the aperiodic isolator are effectively reduced after the optimization.Finally,the experiments of the three different vibration isolation systems are conducted for verifying the analysis work.展开更多
Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and pote...Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice.展开更多
Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.D...Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.Direct manufacturing often leads to high internal surface roughness,which traditional finishing and measuring methods cannot adequately address due to the decreasing size and increasing complexity of internal structures.This is especially true for components like pipes with large aspect ratios,extremely small deep holes,multi-stage bends,cross pipes,and array holes.To meet the high-performance manufacturing demands of these parts,advanced internal surface finishing and roughness measurement technologies have gained significant attention.This review focuses on the challenges and solutions related to internal surface parts with various apertures and complex structures.Internal surface finishing methods are categorized into mechanical finishing,fluid-based finishing,and energy-field-based finishing based on their characteristics.Roughness measurement technologies are divided into tool-probing and non-probing methods.The principles,required equipment,and key parameters of each finishing and measurement approach are discussed in detail.Additionally,the advantages and limitations of these methods are summarized,and future trends are forecasted.This paper serves as a comprehensive guide for researchers and engineers aiming to enhance the internal surface quality of complex structure parts.展开更多
Nonlinear internal waves(NLIWs)exhibit robust dynamic submesoscale motions,connecting large-scale tides to smallscale shear instabilities in the ocean.Previous studies have mainly focused on their generation mechanism...Nonlinear internal waves(NLIWs)exhibit robust dynamic submesoscale motions,connecting large-scale tides to smallscale shear instabilities in the ocean.Previous studies have mainly focused on their generation mechanisms and evolution along their paths.Considering their global distribution resulting from the primary origin in tide-topography interaction,there is an increasing cross-disciplinary interest in understanding how these energetic and ubiquitous NLIWs contribute to sediment redistribution in the ocean.This paper presents fundamental theories on NLIWs and comprehensively reviews triggering mechanisms,different types of instability,and sediment responses by summarizing recent theoretical parameterizations,numerical simulations,laboratory experiments,and in-situ observations.We specifically focus on elucidating various types of instability along with their impact on sediment dynamic processes.Finally,we outline several unresolved issues that require further exploration for a quantitative investigation into NLIWinduced sediment transfer in the ocean.展开更多
As an emerging multifunctional metal with the lowest melting point except for mercury,gallium combines a wide range of metallic and non-metallic elements to form advanced semiconductors critically important in cutting...As an emerging multifunctional metal with the lowest melting point except for mercury,gallium combines a wide range of metallic and non-metallic elements to form advanced semiconductors critically important in cutting-edge technologies.However,due to its low melting point and poor machinability,it is quite difficult to simultaneously characterize gallium’s elastic properties and damping characteristics using conventional methods,which is es-sential in designing and evaluating gallium-based structures.Therefore,developing effective methods to achieve accurate and efficient measurements of Young’s modulus and corresponding internal friction of gallium is of great significance.This letter studies simultaneous measurements of the variations in Young’s modulus and internal friction of gallium at varying temperatures by employing the modified piezoelectric ultrasonic composite oscil-lator technique.Combining the explicit theoretical formulas with the measured resonance and anti-resonance frequencies,it has been discovered that Young’s modulus undergoes an approximately linear decrease as the temperature rises,declining from 83.84 GPa at -70℃ to 79.37 GPa at 20℃.Moreover,like aluminum in the same Group ⅢA of the Periodic Table of Elements and exhibits a grain-boundary internal friction peak,gallium displays a longitudinal internal friction peak at approximately-12°C,with the peak value reaching 1.77×10^(-3).This basic research on gallium’s elastic properties and damping characteristics under low-temperature condi-tions will inspire further explorations of the mechanical properties of a diverse spectrum of low-melting-point functional materials and facilitate applications of gallium-based structures under complex conditions.展开更多
BACKGROUND Hemorrhoids,a prevalent chronic condition globally,significantly impact patients'quality of life.While various surgical interventions,such as external stripping and internal ligation,procedure for prola...BACKGROUND Hemorrhoids,a prevalent chronic condition globally,significantly impact patients'quality of life.While various surgical interventions,such as external stripping and internal ligation,procedure for prolapse and hemorrhoids,and tissue selecting technique,are employed for treatment,they are often associated with postoperative complications,including unsatisfactory defecation,bleeding,and anal stenosis.In contrast,Xiaozhiling injection,a traditional Chinese medicine-based therapy,has emerged as a minimally invasive and effective alternative for internal hemorrhoids.This treatment offers distinct advantages,such as reduced dietary restrictions,broad applicability,and minimal induction of systemic inflammatory responses.Additionally,Xiaozhiling injection effectively eliminates hemorrhoid nuclei,prevents local tissue necrosis,preserves anal cushion integrity,and mitigates postoperative complications,including bleeding and prolapse.Despite its clinical efficacy,the molecular mechanisms underlying its therapeutic effects remain poorly understood,warranting further investigation.AIM To investigate the molecular mechanism underlying the therapeutic effect of Xiaozhiling injection in the treatment of internal hemorrhoids.METHODS An internal hemorrhoid model was established in rats,and the rats were randomly divided into a modeling group[control group(CK group)]and a treatment group.One week after injection,Stereo-seq and electron microscopy were used to study the changes in gene expression and subcellular structures in fibroblasts.RESULTS Single-cell sequencing revealed differences in the expression and transcript levels of the genes collagen 3 alpha 1,decorin,and actin alpha 2 in fibroblasts between the CK group and the treatment group.Spatial transcriptome analysis revealed that genes of the sphingosine kinase 1(Sphk1)/sphingosine-1-phosphate(S1P)pathway spatially overlapped with key genes of the transforming growth factor beta 1 pathway,namely,Sphk1,S1P receptor,and transforming growth factor beta 1,in the treatment group.The proportion of fibroblasts was lower in the treatment group than in the CK group,and Xiaozhiling treatment had a significant effect on the proportion of fibroblasts in hemorrhoidal tissue.Immunohistochemistry revealed a significant increase in the expression of a fibroblast marker.Electron microscopy showed that the endoplasmic reticulum of fibroblasts contained a large amount of glycogen,indicating cell activation.Fibroblast activation and the expression of key genes of the Sphk1-S1P pathway could be observed at the injection site,suggesting that after Xiaozhiling intervention,the Sphk1-S1P pathway could be activated to promote fibrosis.CONCLUSION Xiaozhiling injection exerts its therapeutic effects on internal hemorrhoids by promoting collagen synthesis and secretion in fibroblasts.After Xiaozhiling intervention,the Sphk1-S1P pathway can be activated to promote fibrosis.展开更多
The hydro-mechanical responses of vegetated deposited slopes are complex and far from clear.On one hand,the soils in deposited slopes are typically poorly consolidated and widely graded,making them vulnerable to inter...The hydro-mechanical responses of vegetated deposited slopes are complex and far from clear.On one hand,the soils in deposited slopes are typically poorly consolidated and widely graded,making them vulnerable to internal erosion during rainfall infiltration.On the other hand,vegetation plays a significant role in influencing the hydro-mechanical properties of the soil at the slope surface.This paper presents a coupled seepage-erosion model to investigate the rainfall-induced internal erosion process within vegetated deposited slopes and its impact on slope stability.The detailed seepage-erosion coupling processes were simulated for a series of 1D rooted soil columns with varying root distributions,as well as 2D vegetated layered slopes under both light and heavy rainfall conditions.The numerical results reveal that roots can significantly mitigate rainfall-induced internal erosion,even with shallow root lengths.However,their protective effect on the slope increases as the root density in the superficial soil layer increases.Transpiration can rapidly restore matric suction in the shallow soil during rain intervals,slowing the rainfall-induced seepage-erosion process and thereby increasing slope stability.However,in the absence of transpiration,roots may either accelerate or inhibit the seepage-erosion process,depending on the specific rainfall conditions.展开更多
The internal solitary wave(ISW)represents a frequent and severe oceanic dynamic phenomenon observed in the South China Sea,exposing marine structures to sudden loads.This paper examines the prediction model of interac...The internal solitary wave(ISW)represents a frequent and severe oceanic dynamic phenomenon observed in the South China Sea,exposing marine structures to sudden loads.This paper examines the prediction model of interaction loads between ISW and FPSO,accounting for varying attack angles and incorporating ISW theories.The research demonstrates that the horizontal and transverse forces on FPSO under internal solitary waves(ISWs)comprise wave pressure difference force and viscous force,while the vertical force primarily consists of vertical wave pressure difference force.The wave pressure difference force is determined using the Froude-Krylov equation.The viscous force is derived from the tangential particle velocity induced by ISW and the viscous coefficient.The viscous coefficient formula is obtained through regression analysis of experimental data with different ISW attack angles.The research reveals that the horizontal viscous coefficient C_(vx)decreases as Reynolds number(R_(e))increases,while the transverse viscous coefficient C_(vy)initially increases and subsequently decreases with the growth of the Keulegan-Carpenter number(KC).Moreover,changes in wave propagation direction significantly affect the extreme magnitudes of both horizontal and transverse forces,and simultaneously modify the transverse force orientation,while having minimal impact on the vertical force.Additionally,the forces increase with the ISW’s amplitude.For horizontal and transverse forces,a thinner upper fluid layer generates larger forces.Comparative analysis of experimental,numerical,and theoretical results indicates strong agreement between theoretical predictions and experimental and numerical outcomes.展开更多
Understanding the coupling relationships among lake physicochemical properties,internal nutrient recycling,and related microbes is key for the control of freshwater eutrophication.In this study,seasonal variations in ...Understanding the coupling relationships among lake physicochemical properties,internal nutrient recycling,and related microbes is key for the control of freshwater eutrophication.In this study,seasonal variations in microorganisms at the sediment–water interface(SWI)of the eutrophic Lake Chaohu in China were analyzed,in order to reveal changes in phosphorus(P)-cycling-related microbes in the sediments and its association with internal P release during the cyanobacterial life cycle.The identified P-cycling-related microbes include phosphorus-solubilizing bacteria(PSB)(dominant of Bacillus,Thiobacillus and Acinetobacter),sulfate-reducing bacteria(SRB)(dominant of Sva0081_sediment_group,norank_c__Thermodesulfovibrionia and Desulfatiglans)and iron-reducing bacteria(FeRB)(dominant of Geothermobacter,Anaeromyxobacter,Thermoanaerobaculum and Clostridium_sensu_stricto_1).Increased PSB and reduced proportions of iron-aluminum–bound P(Fe/Al-P)and calcium–bound P(Ca-P)from the benthic stage to initial cyanobacterial growth indicated that internal phosphorus was released through the solubilization of Fe/Al-P and Ca-P by PSB.Growth of cyanobacteria was accompanied by cyanobacteria death,deposition,and degradation during early algal blooms,which increased SRB caused by high organic matter and the net deposition of phosphorus in the western lake.Conversely,phosphorus release in eastern lake was observed because of organic phosphorus mineralization.High linear discriminant analysis effect size of SRB and FeRB and the decreased Fe/Al-P in sediments indicated sulfide-mediated chemical iron reduction(SCIR)and FeRB-mediated microbial iron reduction mechanisms for internal phosphorus release during late algal blooms.The observed seasonal pattern of P-cycling-related microbes and its mediation on internal phosphorus release provides a foundation for internal P management in Lake Chaohu.展开更多
The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structu...The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structural integrity of steel gas pipelines that uses advanced numerical modeling techniques to anticipate fracture development and corrosion effects.The objective is to increase pipeline dependability and safety through more precise,real-time health evaluations.Compared to previous approaches,our solution provides higher accuracy in fault detection and quantification,making it ideal for pipeline integritymonitoring in real-world applications.To solve this issue,statistical analysis was conducted on the size and directional distribution features of about 380,000 sets of internal corrosion faults,as well as simulations of erosion and wear patterns on bent pipes.Using real defectmorphologies,we developed a modeling framework for typical interior corrosion flaws.We evaluated and validated the applicability and effectiveness of in-service inspection processes,as well as conducted on-site comparison tests.The results show that(1)the length and width of corrosion defects follow a log-normal distribution,the clock orientation follows a normal distribution,and the peak depth follows a Freundlich EX function distribution pattern;(2)pipeline corrosion defect data can be classified into three classes using the K-means clustering algorithm,allowing rapid and convenient acquisition of typical size and orientation characteristics of internal corrosion defects;(3)the applicability range and boundary conditions of various NDT techniques were verified,establishing comprehensive selection principles for internal corrosion defect detection technology;(4)on-site inspection results showed a 31%The simulation and validation platform for typical interior corrosion issues greatly enhances the accuracy and reliability of detection data.展开更多
基金supported by the National Natural Science Foundation of China(No.51905123)Major Scientific and Technological Innovation Program of Shandong Province,China(Nos.2020CXGC010303,2022ZLGX04)Key R&D Programme of Shandong Province,China(No.2022JMRH0308).
文摘An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic algorithm.After validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine Vumat.By comparing the simulated results with the experimental results,the application of the ISV model was proven to be reliable.Meanwhile,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture strengthening.Besides,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.
文摘The authors(Cai et al.,2022)claim that their proposed machine learning(ML)models,which are based on three typical ML algorithms and are trained to predict the burst capacity of pitting corroded pipelines,perform better than the existing semi-empirical formulas recommended by the international engineering code developers,DNV and ASME.The authors’assessments of the semi-empiri‐cal burst capacity formulas in Figure 10(a)and Table 8(Cai et al.,2022)incorrectly indicate that DNVGL-RP F101,ASME B31G,and modified ASME B31G are dan‐gerously unsafe due to significantly overestimating burst pressures in several cases.In contrast to the results and conclusions in Cai et al.
文摘Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with HMMH who were admitted to the hospital from June 2019 to June 2024 were selected.The minimum diameter of the macular hole(MH)in all patients was≤500μm.The patients were randomly divided into two groups.The experimental group received 25G pars plana vitrectomy(PPV)combined with ILM flipping and covering technique,while the reference group received PPV combined with ILM peeling.The efficacy indicators and best corrected visual acuity levels were compared between the two groups.Results:The MH closure rate and retinal reattachment rate were higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The best corrected visual acuity level was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The Chinese version of the Visual Function-Related Quality of Life Questionnaire-25(CVRQOL-25)score was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).No serious complications were observed in both groups postoperatively,and there was no difference between the two groups(P>0.05).Conclusion:The ILM flipping and covering technique can improve the MH closure rate and retinal reattachment rate in patients with HMMH(diameter≤500μm),enhance the best corrected visual acuity level,and improve the quality of life related to visual function,with fewer postoperative complications.
文摘Developing an efficient photocatalyst is the key to realize the practical application of photocatalysis.The S-scheme heterojunction has great potential in photocatalysis due to its unique charge-carrier migration pathway,effective light absorption and high redox capacity.However,further enhancing the built-in electric field of the S-scheme,accelerating carrier separation,and achieving higher photocatalytic performance remain unresolved challenges.Herein,based on the continuously adjustable band structure of continuous solid-solution,a novel 0D/2D all solid-solution S-scheme heterojunction with adjustable internal electric field was designed and fabricated by employing a solid-solution of ZnxCd_(1–x)S and Bi_(2)MoyW_(1–y)O_(6)respectively as reduction and oxidation semiconductors.The synergistic optimization of effective light absorption,fast photogenerated carrier separation,and high redox potential leads can be tuned to promote photocatalytic activity.Under visible light,the S-scheme system constructed by Zn_(0.4)Cd_(0.6)S quantum dot(QDs)and Bi_(2)Mo_(0.2)W_(0.8)O_(6)monolayer exhibits a high rate for photocatalytic degradation C_(2)H_(4)(150.6×10^(–3)min^(–1)),which is 16.5 times higher than that of pure Zn_(0.4)Cd_(0.6)S(9.1×10^(–3)min^(–1))and 53.8 times higher than pure Bi_(2)Mo_(0.2)W_(0.8)O_(6)(2.8×10^(–3)min^(–1)).Due to the unique charge-carrier migration pathway,photo-corrosion of Zn_(x)Cd_(1–x)S is further inhibited simultaneously.In-situ irradiation X-ray photoelectron spectroscopy,photoluminescence spectroscopy,time-resolved photoluminescence,transient absorption spectroscopy and electron paramagnetic resonance provide compelling evidence for interfacial charge transfer via S-scheme pathways,while in-situ diffuse reflectance infrared Fourier transform spectroscopy identifies the reaction pathway for C_(2)H_(4)degradation.This novel S-scheme photocatalysts demonstrates excellent performance and potential for the practical application of the fruits and vegetables preservation at room temperatures.
基金financial support from the National Natural Science Foundation of China(Nos.22271024,21632005)Changzhou University.
文摘Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,providing a wide variety of corresponding linear carboxylic esters bearing various functional groups in good yields and>20:1 linear/branch ratios.The reaction is optionally simple and does not need to use CO gas and acid co-catalysts.
文摘Migration is a complex demographic phenomenon.Its dynamics can be explained by several factors whose spatial and temporal evolution is not easy to control.That is why this article aims to understand the factors of migration from a spatiotemporal perspective to fill the gaps in the literature.The aim of this article is to analyse the spatiotemporal dynamics of internal migration factors to deduce the zones of origin and destination in Burkina Faso.To do this,several types of data were used.These included secondary,spatial,statistical and survey data.The results of this study show that the influence of internal migration factors is uneven.The spatial distribution of internal migration factors follows a north-south gradient,with favourable conditions in the south.In fact,the northern part is characterised by a large population exodus,with around 42.6%of outgoing internal migrants,and the southern part by a large population influx.This southern part of the country receives around 34.6%of internal migrants.The areas from which migrants depart have unfavourable climatic,environmental,or socio-economic conditions,whereas the areas to which migrants migrate are characterised by favourable conditions for these factors.
基金The Doctor Foundation of Hebei Normal University of Science and Technology under contract No.2024YB039the Fundamental Research Funds for the Provincial Universities of Hebei under contract Nos 2023JK07 and 2022JK03+3 种基金the Major Science and Technology Support Project of Hebei Province under contract No.242S3301Zthe Fujian Provincial Natural Science Foundation of China under contract No.2021J05172the National Natural Science Foundation of China under contract No.42176244the CAS Key Deployment Project of Centre for Ocean Mega-Research of Science under contract No.COMS2020Q07.
文摘We use a high-resolution numerical simulation to analyze the generation and evolution of semidiurnal internal tides in the Weddell-Scotia Confluence.Our results indicate that two ridges near the Antarctic Peninsula,the South Scotia Ridge(SSR)and the Philip Ridge(PR),are energetic sources of semidiurnal internal tides.The strongest semidiurnal barotropic to baroclinic energy conversion occurs around the crest of the SSR,reaching 0.3 W/m^(2).The depthintegrated,tidally averaged semidiurnal internal tide energy fluxes that radiated from the SSR reach about 2 kW/m.The northward semidiurnal internal tide energy fluxes entering the Scotia Sea are stronger than the southward energy fluxes entering the Powell Basin.For the SSR region between the South Orkney Plateau and Elephant Island,the areaintegrated barotropic to baroclinic conversion rate is 0.71 GW,of which 0.56 GW(79%)dissipates locally.The dissipation of internal tides occurs mainly in water depths of less than 1000 m.The dissipation rate over the SSR is as high as 10−7 W/kg.The energy fluxes create an anticlockwise gyre between the SSR and PR.The horizontal kinetic energy and available potential energy oscillate sinusoidally with peaks occurring at quarter-wavelength intervals.This energy pattern suggests the formation of standing waves due to interference between the semidiurnal internal tides originating from the SSR and PR.The results of this study show that internal tides and related mixing need to be considered in the analysis of water mass transformation in the Southern Ocean.
基金National Natural Science Foundation of China(22178228,22378271)are gratefully acknowledged。
文摘The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas holdup.Firstly,gas holdup measurement method is improved by conducting multi-point liquid level measurement and using net fluid volume instead of bed volume to calculate gas holdup.Then,a stable conductivity method for liquid macromixing has been established by shielding large bubbles using#16nylon mesh.Subsequently,the influences of internal coverage(=12.6%,18.9% and 25.1%) on macroscopic fluid dynamics in a bubble column with a free wall area are systematically investigated.It is found that the presence of internals has a notable effect on macroscopic fluid dynamics.The overall gas holdup and gas-liquid volumetric mass transfer coefficient decrease,and the macromixing time decreases with the increase of internal cross-sectional area coverage.These are mainly caused by the uneven distribution of airflow due to the low resistance in the free wall area.This design makes maintenance easier,but in reality,the reactor performance has decreased.Further improvements will be made to the reactor performance based on such a configuration through flow guidance using baffles.
基金supported by the National Natural Science Foundation of China(No.41876015)。
文摘Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geostrophic flows,respectively.Ocean current is composed of multiple flows;thus,internal tides and lee waves occur concurrently in the real ocean.In this paper,the Massachusetts Institute of Technology general circulation model(MITgcm)is used to conduct 2D numerical experiments.By varying background flow intensities,the energy and dissipation relationship between internal tides and lee waves are investigated.The results reveal that the internal tide beams become asymmetric due to the influence of Doppler shift.The lee wave structure gradually leads the wave field when the background flow velocity rises constantly.The presence of a background flow increases the energy portion of the high-mode wave by up to 15%-20%.Moreover,strong shear,owing to the background flow,considerably increases dissipation.When the background flow velocity is higher than the barotropic tidal current velocity,the isopycnal overturn triggered by the lee wave generates a dissipation of the same order of magnitude as the shear.
基金supported by the National Natural Science Foundation of China(Grant no.42176244)CAS Key Deployment Project of Centre for Ocean Mega-Research of Science(Grant no.COMS2020Q07)。
文摘In the Arctic Ocean,turbulent mixing drives vertical heat flux,thereby affecting the sea ice variability.Internal wave is regarded as one of the important energy sources of mixing in this region.The high latitude and sea ice cover make internal wave in the Arctic Ocean apparently differs from that in mid-and low-latitude oceans.However,the internal wave and its underlying mechanism are less understood due to the lack of observations.This paper briefly reviews the recent studies and unresolved questions on the internal wave in the Arctic Ocean,including wind-driven near-inertial wave,internal tide,and high-frequency internal wave.The aim is to provide new insights for in-depth research in the future,with a focus on the mechanisms responsible for the evolution of internal wave under the rapidly changing Arctic climate.
基金supported by the National Key Research and Development Plan of China (Grant No.2023YFB3406302)Guangdong Basic and Applied Basic Research Foundation (Grant No.2024A1515011126)the Key Research and Development Plan of Shanxi (Grant No.2024GH-ZDXM-29)。
文摘Periodic isolator is well known for its wave filtering characteristic.While in middle and high frequencies,the internal resonances of the periodic isolator are evident especially when damping is small.This study proposes a novel aperiodic vibration isolation for improving the internal resonances control of the periodic isolator.The mechanism of the internal resonances control by the aperiodic isolator is firstly explained.For comparing the internal resonances suppression effect of the aperiodic isolator with the periodic isolator,a dynamic model combing the rigid machine,the isolator,and the flexible plate is derived through multi subsystem modeling method and transfer matrix method,whose accuracy is verified through the finite element method.The influences of the aperiodicity and damping of the isolator on the vibration isolation performance and internal resonances suppression effect are investigated by numerical analysis.The numerical results demonstrate that vibration attenuation performances of the periodic isolator and aperiodic isolator are greatly over than that of the continuous isolator in middle and high frequencies.The aperiodic isolator opens the stop bandgaps comparing with the periodic isolator where the pass bandgaps are periodically existed.The damping of the isolator has the stop bandgap widening effect on both the periodic isolator and the aperiodic isolator.In addition,a parameter optimization algorithm of the aperiodic isolator is presented for improving the internal resonances control effect.It is shown that the vibration peaks within the target frequency band of the aperiodic isolator are effectively reduced after the optimization.Finally,the experiments of the three different vibration isolation systems are conducted for verifying the analysis work.
基金supported by the National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2018ZX09201018–028)the nuclear energy development projects of China during the 13thFive Year Plan periodthe key research and development project of the Sichuan Provincial Department of Science and Technology(No.18ZDYF1466)。
文摘Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice.
基金the financial supports from National Key R&D Program of China(No.2022YFB3403301)the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.52311530080)。
文摘Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.Direct manufacturing often leads to high internal surface roughness,which traditional finishing and measuring methods cannot adequately address due to the decreasing size and increasing complexity of internal structures.This is especially true for components like pipes with large aspect ratios,extremely small deep holes,multi-stage bends,cross pipes,and array holes.To meet the high-performance manufacturing demands of these parts,advanced internal surface finishing and roughness measurement technologies have gained significant attention.This review focuses on the challenges and solutions related to internal surface parts with various apertures and complex structures.Internal surface finishing methods are categorized into mechanical finishing,fluid-based finishing,and energy-field-based finishing based on their characteristics.Roughness measurement technologies are divided into tool-probing and non-probing methods.The principles,required equipment,and key parameters of each finishing and measurement approach are discussed in detail.Additionally,the advantages and limitations of these methods are summarized,and future trends are forecasted.This paper serves as a comprehensive guide for researchers and engineers aiming to enhance the internal surface quality of complex structure parts.
基金The Interdisciplinary Joint Research Projects of Tongji University,Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai).
文摘Nonlinear internal waves(NLIWs)exhibit robust dynamic submesoscale motions,connecting large-scale tides to smallscale shear instabilities in the ocean.Previous studies have mainly focused on their generation mechanisms and evolution along their paths.Considering their global distribution resulting from the primary origin in tide-topography interaction,there is an increasing cross-disciplinary interest in understanding how these energetic and ubiquitous NLIWs contribute to sediment redistribution in the ocean.This paper presents fundamental theories on NLIWs and comprehensively reviews triggering mechanisms,different types of instability,and sediment responses by summarizing recent theoretical parameterizations,numerical simulations,laboratory experiments,and in-situ observations.We specifically focus on elucidating various types of instability along with their impact on sediment dynamic processes.Finally,we outline several unresolved issues that require further exploration for a quantitative investigation into NLIWinduced sediment transfer in the ocean.
基金financially supported by the National Key R&D Program of China(Grant No.2023YFF0716800)the National Natural Science Foundation of China(Grant No.12074160)the Natural Science Foundation of Liaoning Province of China(Grant No.2024-MS-181).
文摘As an emerging multifunctional metal with the lowest melting point except for mercury,gallium combines a wide range of metallic and non-metallic elements to form advanced semiconductors critically important in cutting-edge technologies.However,due to its low melting point and poor machinability,it is quite difficult to simultaneously characterize gallium’s elastic properties and damping characteristics using conventional methods,which is es-sential in designing and evaluating gallium-based structures.Therefore,developing effective methods to achieve accurate and efficient measurements of Young’s modulus and corresponding internal friction of gallium is of great significance.This letter studies simultaneous measurements of the variations in Young’s modulus and internal friction of gallium at varying temperatures by employing the modified piezoelectric ultrasonic composite oscil-lator technique.Combining the explicit theoretical formulas with the measured resonance and anti-resonance frequencies,it has been discovered that Young’s modulus undergoes an approximately linear decrease as the temperature rises,declining from 83.84 GPa at -70℃ to 79.37 GPa at 20℃.Moreover,like aluminum in the same Group ⅢA of the Periodic Table of Elements and exhibits a grain-boundary internal friction peak,gallium displays a longitudinal internal friction peak at approximately-12°C,with the peak value reaching 1.77×10^(-3).This basic research on gallium’s elastic properties and damping characteristics under low-temperature condi-tions will inspire further explorations of the mechanical properties of a diverse spectrum of low-melting-point functional materials and facilitate applications of gallium-based structures under complex conditions.
基金Supported by the National Natural Science Foundation of China,No.81774118the Foreign Cooperation Project of Science and Technology Department of Fujian Province,No.2023I0021the Medical Innovation Project of Fujian Province,No.2024CXB013.
文摘BACKGROUND Hemorrhoids,a prevalent chronic condition globally,significantly impact patients'quality of life.While various surgical interventions,such as external stripping and internal ligation,procedure for prolapse and hemorrhoids,and tissue selecting technique,are employed for treatment,they are often associated with postoperative complications,including unsatisfactory defecation,bleeding,and anal stenosis.In contrast,Xiaozhiling injection,a traditional Chinese medicine-based therapy,has emerged as a minimally invasive and effective alternative for internal hemorrhoids.This treatment offers distinct advantages,such as reduced dietary restrictions,broad applicability,and minimal induction of systemic inflammatory responses.Additionally,Xiaozhiling injection effectively eliminates hemorrhoid nuclei,prevents local tissue necrosis,preserves anal cushion integrity,and mitigates postoperative complications,including bleeding and prolapse.Despite its clinical efficacy,the molecular mechanisms underlying its therapeutic effects remain poorly understood,warranting further investigation.AIM To investigate the molecular mechanism underlying the therapeutic effect of Xiaozhiling injection in the treatment of internal hemorrhoids.METHODS An internal hemorrhoid model was established in rats,and the rats were randomly divided into a modeling group[control group(CK group)]and a treatment group.One week after injection,Stereo-seq and electron microscopy were used to study the changes in gene expression and subcellular structures in fibroblasts.RESULTS Single-cell sequencing revealed differences in the expression and transcript levels of the genes collagen 3 alpha 1,decorin,and actin alpha 2 in fibroblasts between the CK group and the treatment group.Spatial transcriptome analysis revealed that genes of the sphingosine kinase 1(Sphk1)/sphingosine-1-phosphate(S1P)pathway spatially overlapped with key genes of the transforming growth factor beta 1 pathway,namely,Sphk1,S1P receptor,and transforming growth factor beta 1,in the treatment group.The proportion of fibroblasts was lower in the treatment group than in the CK group,and Xiaozhiling treatment had a significant effect on the proportion of fibroblasts in hemorrhoidal tissue.Immunohistochemistry revealed a significant increase in the expression of a fibroblast marker.Electron microscopy showed that the endoplasmic reticulum of fibroblasts contained a large amount of glycogen,indicating cell activation.Fibroblast activation and the expression of key genes of the Sphk1-S1P pathway could be observed at the injection site,suggesting that after Xiaozhiling intervention,the Sphk1-S1P pathway could be activated to promote fibrosis.CONCLUSION Xiaozhiling injection exerts its therapeutic effects on internal hemorrhoids by promoting collagen synthesis and secretion in fibroblasts.After Xiaozhiling intervention,the Sphk1-S1P pathway can be activated to promote fibrosis.
基金supported by National Natural Science Foundation of China(Grant No.42372330)Science and Technology Research Program of Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(Grant No.IMHE-CXTD-01-IMHE-ZYTS-12)Sichuan Science and Technology Program(Grant No.2024NSFSC0102).
文摘The hydro-mechanical responses of vegetated deposited slopes are complex and far from clear.On one hand,the soils in deposited slopes are typically poorly consolidated and widely graded,making them vulnerable to internal erosion during rainfall infiltration.On the other hand,vegetation plays a significant role in influencing the hydro-mechanical properties of the soil at the slope surface.This paper presents a coupled seepage-erosion model to investigate the rainfall-induced internal erosion process within vegetated deposited slopes and its impact on slope stability.The detailed seepage-erosion coupling processes were simulated for a series of 1D rooted soil columns with varying root distributions,as well as 2D vegetated layered slopes under both light and heavy rainfall conditions.The numerical results reveal that roots can significantly mitigate rainfall-induced internal erosion,even with shallow root lengths.However,their protective effect on the slope increases as the root density in the superficial soil layer increases.Transpiration can rapidly restore matric suction in the shallow soil during rain intervals,slowing the rainfall-induced seepage-erosion process and thereby increasing slope stability.However,in the absence of transpiration,roots may either accelerate or inhibit the seepage-erosion process,depending on the specific rainfall conditions.
基金supported by JUST Start-up Fund for Science Research,the Jiangsu Natural Science Foundation(Grant No.BK20210885).
文摘The internal solitary wave(ISW)represents a frequent and severe oceanic dynamic phenomenon observed in the South China Sea,exposing marine structures to sudden loads.This paper examines the prediction model of interaction loads between ISW and FPSO,accounting for varying attack angles and incorporating ISW theories.The research demonstrates that the horizontal and transverse forces on FPSO under internal solitary waves(ISWs)comprise wave pressure difference force and viscous force,while the vertical force primarily consists of vertical wave pressure difference force.The wave pressure difference force is determined using the Froude-Krylov equation.The viscous force is derived from the tangential particle velocity induced by ISW and the viscous coefficient.The viscous coefficient formula is obtained through regression analysis of experimental data with different ISW attack angles.The research reveals that the horizontal viscous coefficient C_(vx)decreases as Reynolds number(R_(e))increases,while the transverse viscous coefficient C_(vy)initially increases and subsequently decreases with the growth of the Keulegan-Carpenter number(KC).Moreover,changes in wave propagation direction significantly affect the extreme magnitudes of both horizontal and transverse forces,and simultaneously modify the transverse force orientation,while having minimal impact on the vertical force.Additionally,the forces increase with the ISW’s amplitude.For horizontal and transverse forces,a thinner upper fluid layer generates larger forces.Comparative analysis of experimental,numerical,and theoretical results indicates strong agreement between theoretical predictions and experimental and numerical outcomes.
基金supported by the National Natural Science Foundation of China(No.U22A20616).
文摘Understanding the coupling relationships among lake physicochemical properties,internal nutrient recycling,and related microbes is key for the control of freshwater eutrophication.In this study,seasonal variations in microorganisms at the sediment–water interface(SWI)of the eutrophic Lake Chaohu in China were analyzed,in order to reveal changes in phosphorus(P)-cycling-related microbes in the sediments and its association with internal P release during the cyanobacterial life cycle.The identified P-cycling-related microbes include phosphorus-solubilizing bacteria(PSB)(dominant of Bacillus,Thiobacillus and Acinetobacter),sulfate-reducing bacteria(SRB)(dominant of Sva0081_sediment_group,norank_c__Thermodesulfovibrionia and Desulfatiglans)and iron-reducing bacteria(FeRB)(dominant of Geothermobacter,Anaeromyxobacter,Thermoanaerobaculum and Clostridium_sensu_stricto_1).Increased PSB and reduced proportions of iron-aluminum–bound P(Fe/Al-P)and calcium–bound P(Ca-P)from the benthic stage to initial cyanobacterial growth indicated that internal phosphorus was released through the solubilization of Fe/Al-P and Ca-P by PSB.Growth of cyanobacteria was accompanied by cyanobacteria death,deposition,and degradation during early algal blooms,which increased SRB caused by high organic matter and the net deposition of phosphorus in the western lake.Conversely,phosphorus release in eastern lake was observed because of organic phosphorus mineralization.High linear discriminant analysis effect size of SRB and FeRB and the decreased Fe/Al-P in sediments indicated sulfide-mediated chemical iron reduction(SCIR)and FeRB-mediated microbial iron reduction mechanisms for internal phosphorus release during late algal blooms.The observed seasonal pattern of P-cycling-related microbes and its mediation on internal phosphorus release provides a foundation for internal P management in Lake Chaohu.
基金The“13th Five-Year Plan”National Science and Technology Major Project,2016ZX05052,Changchao QiThe China National Petroleum Corporation Science and Technology Project,2021DJ6505,Changchao Qi.
文摘The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structural integrity of steel gas pipelines that uses advanced numerical modeling techniques to anticipate fracture development and corrosion effects.The objective is to increase pipeline dependability and safety through more precise,real-time health evaluations.Compared to previous approaches,our solution provides higher accuracy in fault detection and quantification,making it ideal for pipeline integritymonitoring in real-world applications.To solve this issue,statistical analysis was conducted on the size and directional distribution features of about 380,000 sets of internal corrosion faults,as well as simulations of erosion and wear patterns on bent pipes.Using real defectmorphologies,we developed a modeling framework for typical interior corrosion flaws.We evaluated and validated the applicability and effectiveness of in-service inspection processes,as well as conducted on-site comparison tests.The results show that(1)the length and width of corrosion defects follow a log-normal distribution,the clock orientation follows a normal distribution,and the peak depth follows a Freundlich EX function distribution pattern;(2)pipeline corrosion defect data can be classified into three classes using the K-means clustering algorithm,allowing rapid and convenient acquisition of typical size and orientation characteristics of internal corrosion defects;(3)the applicability range and boundary conditions of various NDT techniques were verified,establishing comprehensive selection principles for internal corrosion defect detection technology;(4)on-site inspection results showed a 31%The simulation and validation platform for typical interior corrosion issues greatly enhances the accuracy and reliability of detection data.
