机器人加工是航天复杂舱段内腔加工的有效手段。针对部分狭窄深腔舱段的加工需求,需在机器人末端附加延长杆以提升操作可达性。然而,延长杆在拓展加工覆盖范围的同时,会增大系统动柔度,极易引发加工颤振,进而影响加工质量与效率。为此,...机器人加工是航天复杂舱段内腔加工的有效手段。针对部分狭窄深腔舱段的加工需求,需在机器人末端附加延长杆以提升操作可达性。然而,延长杆在拓展加工覆盖范围的同时,会增大系统动柔度,极易引发加工颤振,进而影响加工质量与效率。为此,本文提出一种变频可调式调谐质量阻尼器(Tuned mass damper,TMD)的结构设计与参数优化方法,建立了集成调谐质量阻尼器与机器人加工系统的动力学模型。该方法基于偏心曲柄滑块机构实现频率可调,根据电涡流阻尼原理完成阻尼参数调控。进一步开展机器人加工系统动柔度控制试验,结果表明,本文所提方法可使末端动柔度峰值降低67.8%,显著提升加工稳定性边界。展开更多
In performance-based architectural design optimization, the design of building massings and façades is commonly separated, which weakens the effectiveness in performance improvement. In response, this study propo...In performance-based architectural design optimization, the design of building massings and façades is commonly separated, which weakens the effectiveness in performance improvement. In response, this study proposes a hybrid massing-façade integrated design generation and optimization workflow to integrate the two elements in an evolutionary design process. Compared with the existing approaches, the proposed workflow emphasizes the diversity of building design generation, with which various combinations of building massing forms and façade patterns can be systematically explored. Two case studies and a corresponding comparison study are presented to demonstrate the efficacy of the proposed workflow. Results show that the optimization can produce designs coupling the potential of building massings and façades in performance improvement. In addition, the optimization can provide information that supports early-stage architectural design exploration. Such information also enables the architect to understand the performance implications associated with the synergy of building massing and façade design.展开更多
In the past decade,there has been an increasing recognition of the role of computational design optimization in early-stage performance-based architectural design exploration.However,it remains challenging for designe...In the past decade,there has been an increasing recognition of the role of computational design optimization in early-stage performance-based architectural design exploration.However,it remains challenging for designers to apply such optimization-based design explorations in practice.To address this issue,this paper introduces a design tool,called EvoMass,and an associated design method that facilitates design exploration for building massing typologies in performance-based design tasks.EvoMass is capable of offering architects design options reflecting performance-related building massing typologies for the design task,without necessitating advanced computational design skills.More importantly,it can provide architects with insights into the underlying performance implications,thereby enhancing early-stage performance-based design exploration.EvoMass and its associated design method overcome the limitation in the conventional typology-first-optimization-second design procedure adopted by most existing tools,and it promotes a typology-oriented design exploration method of using computational optimization in performance-based architectural design.To demonstrate the efficacy of EvoMass,case studies derived from architectural design studio tasks,incorporating daylighting,solar exposure,and subjective design intents,and the result of a user survey are presented,which highlights how EvoMass and the performance-based design optimization and exploration can enable architects to achieve a more performance-aware design.展开更多
The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of ris...The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of risk substances(including local anesthetics,LAs)in cosmetics,which has been successfully applied in the analysis of actual samples.This work aims to develop a more convenient high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS/MS)method for the quantitative determination of LAs.Samples were ultrasonically extracted with methanol,separated on an Agilent Poroshell 120 EC-C18 column(2.1 mm×100 mm,2.7μm),and eluted with a gradient mobile phase consisting of 0.1%formic acid aqueous solution and methanol.Quantification was performed using the external standard method.The results show that all 23 LAs are effectively separated within 12 minutes,with good linearity in the corresponding concentration ranges and the correlation coefficients all greater than 0.99.The limits of detection(LOD)range from 0.0025 to 0.05μg/g,and the limits of quantification(LOQ)range from 0.01 to 0.1μg/g.The average recoveries of the 23 LAs in 5 blank cosmetic matrices are 80.68%-117.57%,with the relative standard deviations(RSDs)less than 5.98%.This method has good precision and high accuracy,and is suitable for the determination of LAs in 5 cosmetic matrices.展开更多
Dear Editor,Ciliary body masses are diagnostically challenging due to their hidden location,diverse pathologies,and limited examination methods[1].We report a case of a ciliary body inflammatory mass treated with tran...Dear Editor,Ciliary body masses are diagnostically challenging due to their hidden location,diverse pathologies,and limited examination methods[1].We report a case of a ciliary body inflammatory mass treated with trans-scleral excision and antiinflammatory therapy,preserving functional vision.展开更多
The vibration caused by blasting excavation of rock mass frequently poses a threat to the stability of adjacent tunnels.Previous research is limited by the simplification of a rock mass as a homogeneous elastic medium...The vibration caused by blasting excavation of rock mass frequently poses a threat to the stability of adjacent tunnels.Previous research is limited by the simplification of a rock mass as a homogeneous elastic medium,without considering the wave attenuation caused by viscoelasticity and wave separation induced by rock discontinuities,as well as plane waves while neglecting geometric attenuation of near-field nonplane blast waves.This paper establishes a theoretical model of cylindrical P-wave propagation across a fault to an adjacent existing tunnel.Based on the time-domain recursive method,vibration equations and peak particle velocity on the adjacent existing tunnel wall caused by a cylindrical wave passing through a fault are derived.The rock mass and fault are assumed to satisfy Kelvin viscoelastic bodies,and contact interfaces between fault and rock mass follow a nonlinear hyperbolic deformation model in the normal direction and a linear model in the tangential direction.The results show that tunnel vibration caused by the blast cylindrical P-wave is primarily induced by transmitted P-waves.With the increase of the fault dip angle,vibration on the upper side of the adjacent existing tunnel gradually decreases,while vibration on the lower side increases.The closer the vibration to the upper and lower sides,the stronger the shear effect on the tunnel wall,and the closer the vibration to the middle,the stronger the pressure effect on the tunnel wall.Larger fault thickness and higher initial blast wave frequency result in weaker vibration of the adjacent tunnel.The deeper the burial depth,the stronger the vibration of the adjacent tunnel wall.Findings of this study provide insight into the dynamic response of rock construction and safety evaluation in engineering service.展开更多
Understanding the underlying mechanism that enhances the separation of specific target ions from complex background aqueous solutions is crucial for achieving controllable chemical reactions and industrial purificatio...Understanding the underlying mechanism that enhances the separation of specific target ions from complex background aqueous solutions is crucial for achieving controllable chemical reactions and industrial purification processes in modern industries.This study investigated the enhanced kinetic separatio n of target metal ions from complex aqueous solutio ns at a liquid-liquid interface,focusing on the presence of coexisting salt cations.Employing a typical thin-layer organic oil film(TOOF)extraction as a model system,the research examines how background Al^(3+)ions influence the mass transfer and separation of ions.Notably,the co ncentration of Al^(3+)ions affects both the distribution of Er^(3+)ions at the oil-water interface and the arrangement and orientation of P507 extractant molecules through the formation of unique hydrogen-bonding interactions.These interactions influence the selectivity of mass transfer,facilitating the separation of Er^(3+)from Al^(3+)ions.Specifically,the hydration shell of Er^(3+)ions is disrupted due to the strong hydration capability of coexisting Al^(3+)ions,leading to a higher interfacial concentration of Er^(3+)ions and a more ordered interfacial orientation of P507 molecules.At lower concentrations of Al^(3+)ions,the diffusion rate of Er^(3+)ions near the interface is high,enhancing the sepa ration perfo rmance of these ions.In contrast,at higher concentrations of Al^(3+)ions,the competitive hydration by Al^(3+)ions increases,and the interfacial concentration of Er^(3+)ions decreases due to enhanced diffusion resistance,resulting in poorer separation performance.Furthermore,a thinner membrane is more effective than a thicker one in enriching target Er^(3+)ions at the interface and achieving an ordered interfacial orientation of P507 molecules,thereby enhancing the separation coefficient(β_(Er/Al)).This work provides novel insights into the behaviors of ions and extractants at oil-wate r interface and the kinetic separation selectivity under varying concentrations of coexisting salt cations.展开更多
This study investigates catalytic tar cracking over semi-coke catalysts,addressing reaction kinetics challenges by integrating experimental data with a COMSOL Multiphysics model.A multi-physics framework combines cata...This study investigates catalytic tar cracking over semi-coke catalysts,addressing reaction kinetics challenges by integrating experimental data with a COMSOL Multiphysics model.A multi-physics framework combines catalysis,carbon deposition,and self-consumption to analyze toluene(tar model compound)removal.The model evaluates intrinsic catalytic activity,porosity evolution,and porous media flow,revealing that toluene conversion is governed by diffusion/convective mass transfer,homogeneous reactions,and surface reactions influenced by dynamic carbon deposition/removal.Increasing temperature from 973 to 1173 K enhances gas-film heat and mass transfer coefficient,accelerating tar cracking rates and extending catalyst lifetime.Elevated temperatures improve gas-solid phase heat/mass transfer,promoting efficient tar removal during syngas purification.The results highlight the interplay between reaction kinetics,carbon deposition dynamics,and transport phenomena in optimizing semi-coke catalyst performance under high-temperature conditions.展开更多
AIM:To investigate the causal effect of obesity on cataract risk and explores the potential mediating roles of metabolites using Mendelian randomization(MR).METHODS:Summary-level data from large-scale genome-wide asso...AIM:To investigate the causal effect of obesity on cataract risk and explores the potential mediating roles of metabolites using Mendelian randomization(MR).METHODS:Summary-level data from large-scale genome-wide association studies to examine the relationship between obesity and cataract were utilized.Obesity-related traits,including body mass index(BMI),waist-to-hip ratio(WHR),and waist circumference(WC).A two-sample MR approach was employed to assess the causal effect of obesity on cataract risk,while potential mediators were identified from suitable genome-wide association studies(GWAS)datasets.Additionally,a metabolic pathway analysis was conducted.RESULTS:An increase of 1 standard deviation(SD)in BMI,WHR,and WC was associated with a significantly higher risk of cataract(BMI:odds ratio(OR)1.0017,95%confidence interval(CI):1.0001-1.0032,P=0.0320;WHR:OR 1.0029,95%CI:1.0006-1.0051,P=0.0129;WC:OR 1.0020,95%CI:1.0001-1.0038,P=0.0390].These associations remained robust after adjusting for confounding factors in multivariable MR analysis.Furthermore,a two-step MR analysis identified eight potential metabolic mediators,with one mediator showing a significant causal role in the relationship between obesity and cataract.CONCLUSION:This work highlights the importance of addressing obesity as a modifiable risk factor for cataracts,particularly through metabolic pathways.展开更多
Mechanical tension is widely recognized as the primary stimulus underlying the molecular mechanisms that influence muscle hypertrophy induced by resistance training.Despite this,several outdated or overstated concepts...Mechanical tension is widely recognized as the primary stimulus underlying the molecular mechanisms that influence muscle hypertrophy induced by resistance training.Despite this,several outdated or overstated concepts continue to persist,both in the scientific literature and in the practical application of resistance training coaching and program design.Claims that acute hormonal responses,metabolic stress,cell swelling or“the pump”meaningfully contribute to hypertrophy are not supported by scientific evidence.Additionally,the concept of sarcoplasmic hypertrophy as a distinct and functionally meaningful contributor to hypertrophy lacks strong evidence.In this review,we critically evaluate several persistent misconceptions and contrast them with evidence-based mechanistic insights into load-induced hypertrophy.Specifically,we discuss the role(or lack thereof)of systemic hormones,metabolites,and cell swelling in promoting muscle hypertrophy.We also critically review the concept of sarcoplasmic hypertrophy and propose that it is not a meaningful contributor to muscle hypertrophy.Lastly,to translate knowledge for trainees and coaches,we discuss the upper limit of muscle hypertrophy and provide readers with evidence-based,reasonable expectations for muscle hypertrophy.We aimed,through this review,to use scientific evidence to enhance our understanding of what drives muscle hypertrophy and provide an evidence-based framework for resistance exercise training.展开更多
Tajikistan contains the majority of Central Asia’s glaciers,which cover about 6.00%of the national territory;their rapid shrinkage poses a significant threat to regional water resource security.However,glacier monito...Tajikistan contains the majority of Central Asia’s glaciers,which cover about 6.00%of the national territory;their rapid shrinkage poses a significant threat to regional water resource security.However,glacier monitoring in Tajikistan was interrupted after 1991,creating a substantial gap in understanding the current state and temporal evolution of these glaciers.Based on glacier inventory data,in situ measurements,and published literature,this study examined the present status and recent variations of glaciers in Tajikistan through data integration and validation,literature collation and comparative analysis,and the application of Geographic Information System(GIS)spatial analysis techniques.As of 2023,Tajikistan possesses a total of 11,528 glaciers,encompassing an area of 7624.48(±305.58)km2.Small glaciers dominate in number,whereas large glaciers account for the majority of the total area.Over the past two decades,the glacier count has decreased by 2014,and the total area has decreased by 628.98 km2,corresponding to an average annual reduction rate of 0.33%.Regional shrinkage rates range from 4.10%to 22.28%.Glaciers have undergone accelerated mass loss during the past 20 a;only those on the northeastern Pamir Plateau exhibit a weak positive mass balance.Observations of typical monitored glaciers also reveal intensified melting and retreat,consistent with regional trends.In light of the recent acceleration of glacier shrinkage in Tajikistan,focused measures should be implemented to strengthen glacier monitoring,enhance public awareness of glacier preservation,and promote the sustainable development and utilization of glacier tourism.These findings bridge the knowledge gap regarding the spatiotemporal dynamics of Tajikistan’s glaciers over recent decades and provide essential data support for regional water resource management.展开更多
Mass wasting is globally recognized as a key geomorphic agent in permanent gully expansion and greatly contributes to watershed sediment losses.Though its formation process has been assessed by some physical models,th...Mass wasting is globally recognized as a key geomorphic agent in permanent gully expansion and greatly contributes to watershed sediment losses.Though its formation process has been assessed by some physical models,the occurrence and rainfall threshold have been rarely documented.In this study,rainfall-induced mass wasting events in two permanent gullies located in the Mollisols region of Northeast China,with Mollisols(gully 1)and sandy soil(gully 2)underneath were observed,and their differences were explored based on their soil strengths,hydraulic properties,excess topographies,and theoretical rainfall amounts.The sandy soil had a higher strength,faster pore water pressure dissipation rate,and lower suction stress at a specific soil moisture content compared to the black soil.The erosion thickness of the gully bed and sidewalls in gully 1 was shallower compared to gully 2.This was confirmed by the relationship between the erosion thickness and excess topography.The differences in the mass wasting erosion of the gully bed and sidewalls were due to the higher shear strength and well-drained hydraulic properties of the sandy soil compared to the black-soil.An infinite model was chosen to examine the temporal order of the mass wasting in the two gullies.It was found that the mass wasting in gully 2 occurred earlier than that in gully 1.This was likely due to the occurrence of an intense storm with less rainfall at the location of gully 2,while a light storm with heavier rainfall occurred in the location of gully 1.As Mollisols and sandy soil are the typical soil horizons in the Mollisols region worldwide,the results of this work could provide insightful knowledge for understanding the physical process of permanent gully expansion,which may be helpful for developing prediction models for sediment losses in some watersheds with vast Mollisols and highly developed gully system.展开更多
For loops with UV divergences,assuming that the physical contributions of loops from UV regions are insignificant,a UV-free scheme method described by an equation is introduced to derive loop results without UV diverg...For loops with UV divergences,assuming that the physical contributions of loops from UV regions are insignificant,a UV-free scheme method described by an equation is introduced to derive loop results without UV divergences in the calculations,i.e.,a route of the analytic continuation T_(F)→T_(P)besides the traditional route∞-∞in the mathematical structure.This scheme provides a new perspective to an open question of the hierarchy problem of Higgs mass,i.e.,an alternative interpretation without fine-tuning within the standard model.展开更多
Background: Post-workout supplementation has been used in athletes and recreational exercisers;however, responses between normal and overweight individuals on exercise performance and muscle recovery are less known.Me...Background: Post-workout supplementation has been used in athletes and recreational exercisers;however, responses between normal and overweight individuals on exercise performance and muscle recovery are less known.Methods: Normal and overweight young adult males(21 subjects/group) participated in resistance and fatiguing exercises before receiving post-workout supplements: placebo, coenzyme Q10(CoQ10), or sports drink in a crossover design. Resistance exercises included upper body exercise(bench press, upright row, and standing shoulder press) and lower body exercise(dead lift, back squat, and front squat) at 75% of one-repetition maximum(1 RM). Fatiguing exercise was performed on a cycle ergometer with 3 min of all-out effort at 3.5% of body mass. Participants consumed post-workout supplements within 10 min of exercise completion and repeated-bout exercise was performed 1 h later, followed by cardiovascular responses, urinary biomarkers, and delayed onset muscle soreness(DOMS) assessments.Results: There were effects of overweight on resistance exercise volume, critical power, fatigue index, and postexercise diastolic blood pressure(DBP). However, no differences in urinary biomarkers of muscle damage(potassium and creatinine) or DOMS between normal and overweight individuals. After supplementation, CoQ10 and sports drink increased resistance exercise volume regardless of body mass and increased critical power in the normal group. Additionally, CoQ10 supplementation was associated with a reduction in urinary biomarkers and DOMS in both groups.Conclusion: These findings are beneficial for sport scientists, nutritionists, and exercise physiologists in guiding post-workout supplementation with CoQ10 and sports drink to improve exercise performance and muscle recovery in normal and overweight individuals.展开更多
The negative Poisson’s ratio(NPR)bolt is an innovative support element distinguished by its high strength,elongation,and a slightly negative Poisson’s ratio.Unlike conventional prestressed(PR)bolts with a positive P...The negative Poisson’s ratio(NPR)bolt is an innovative support element distinguished by its high strength,elongation,and a slightly negative Poisson’s ratio.Unlike conventional prestressed(PR)bolts with a positive Poisson’s ratio,the NPR bolt exhibits a quasi-ideal plastic response without a prominent yield platform,enabling it to sustain high prestress with a substantial safety margin,which is particularly advantageous for jointed rock masses.However,investigations into the shear resistance mechanisms of NPR bolts under varying prestress levels remain limited.This study conducted full-scale double shear tests to assess the shear strength,deformation behavior,energy absorption,and failure mechanisms of NPR bolts under different prestress conditions.To ensure a fair comparison with PR bolts,a prestress utilization coefficient(PUC)was introduced.The results reveal that at a PUC of 0.25,the NPR bolt achieved peak axial force,shear displacement,and peak shear force values that are 2.41,1.88,and 2.13 times greater than those of the PR bolt,respectively.Shear performance was optimized at a prestress level of 100 kN,with energy absorption reaching 47.1 kJ,which is 2.8 times that of the PR bolt.Furthermore,the necking ratio was significantly reduced,indicating more distributed plastic deformation and delayed failure.Field applications verified the superior performance,resulting in a 27.4%reduction in roof settlement and enhanced structural integrity.These findings confirm that NPR bolts possess excellent shear resistance,energy absorption,and deformation adaptability,and optimizing prestress significantly enhances their support performance,providing a strong basis for geotechnical engineering applications.展开更多
The corrosion wear behavior of the selective laser melting(SLM)and forged TC4 alloys in 3.5 wt.%NaCl solution is studied.Results indicate that the current densities of the two TC4 alloys increase with the increase in ...The corrosion wear behavior of the selective laser melting(SLM)and forged TC4 alloys in 3.5 wt.%NaCl solution is studied.Results indicate that the current densities of the two TC4 alloys increase with the increase in applied potential,meaning that the corrosion resistance of the alloys decreases.And the main product of the passive film is TiO_(2).What’s more,corrosion wear behavior is more severe due to the presence of corrosion,resulting in greater mass losses and deeper wear scars.To explore the interaction between corrosion and wear for the two TC4 alloys,the change of the mass loss proportions for wear caused by corrosion and corrosion caused by wear with potential is analyzed.The mass loss of wear caused by corrosion cannot be ignored,and it affects SLM TC4 alloy with the unique acicularα′-phase significantly.展开更多
Objective Previous studies link lower body mass index(BMI)with increased obsessive-compulsive disorder(OCD)risk,yet other body mass indicators may be more etioloically relevant.We dissected the causal association betw...Objective Previous studies link lower body mass index(BMI)with increased obsessive-compulsive disorder(OCD)risk,yet other body mass indicators may be more etioloically relevant.We dissected the causal association between body fat mass(FM)and OCD.Methods Summary statistics from genome-wide association studies of European ancestry were utilized to conduct two-sample Mendelian randomization analysis.Heterogeneity,horizontal pleiotropy,and sensitivity analyses were performed to assess the robustness.Results The inverse variance weighting method demonstrated that a genetically predicted decrease in FM was causally associated with an increased OCD risk[odds ratio(OR)=0.680,95%confidence interval(CI):0.528–0.875,P=0.003].Similar estimates were obtained using the weighted median approach(OR=0.633,95%CI:0.438–0.915,P=0.015).Each standard deviation increases in genetically predicted body fat percentage corresponded to a reduced OCD risk(OR=0.638,95%CI:0.455–0.896,P=0.009).The sensitivity analysis confirmed the robustness of these findings with no outlier instrument variables identified.Conclusion The negative causal association between FM and the risk of OCD suggests that the prevention or treatment of mental disorders should include not only the control of BMI but also fat distribution and body composition.展开更多
文摘机器人加工是航天复杂舱段内腔加工的有效手段。针对部分狭窄深腔舱段的加工需求,需在机器人末端附加延长杆以提升操作可达性。然而,延长杆在拓展加工覆盖范围的同时,会增大系统动柔度,极易引发加工颤振,进而影响加工质量与效率。为此,本文提出一种变频可调式调谐质量阻尼器(Tuned mass damper,TMD)的结构设计与参数优化方法,建立了集成调谐质量阻尼器与机器人加工系统的动力学模型。该方法基于偏心曲柄滑块机构实现频率可调,根据电涡流阻尼原理完成阻尼参数调控。进一步开展机器人加工系统动柔度控制试验,结果表明,本文所提方法可使末端动柔度峰值降低67.8%,显著提升加工稳定性边界。
文摘In performance-based architectural design optimization, the design of building massings and façades is commonly separated, which weakens the effectiveness in performance improvement. In response, this study proposes a hybrid massing-façade integrated design generation and optimization workflow to integrate the two elements in an evolutionary design process. Compared with the existing approaches, the proposed workflow emphasizes the diversity of building design generation, with which various combinations of building massing forms and façade patterns can be systematically explored. Two case studies and a corresponding comparison study are presented to demonstrate the efficacy of the proposed workflow. Results show that the optimization can produce designs coupling the potential of building massings and façades in performance improvement. In addition, the optimization can provide information that supports early-stage architectural design exploration. Such information also enables the architect to understand the performance implications associated with the synergy of building massing and façade design.
基金supported by the Xi’an Jiaotong-Liverpool University Research Development Fund(RDF-23-01-107)the National Natural Science Foundation of China(52178017)。
文摘In the past decade,there has been an increasing recognition of the role of computational design optimization in early-stage performance-based architectural design exploration.However,it remains challenging for designers to apply such optimization-based design explorations in practice.To address this issue,this paper introduces a design tool,called EvoMass,and an associated design method that facilitates design exploration for building massing typologies in performance-based design tasks.EvoMass is capable of offering architects design options reflecting performance-related building massing typologies for the design task,without necessitating advanced computational design skills.More importantly,it can provide architects with insights into the underlying performance implications,thereby enhancing early-stage performance-based design exploration.EvoMass and its associated design method overcome the limitation in the conventional typology-first-optimization-second design procedure adopted by most existing tools,and it promotes a typology-oriented design exploration method of using computational optimization in performance-based architectural design.To demonstrate the efficacy of EvoMass,case studies derived from architectural design studio tasks,incorporating daylighting,solar exposure,and subjective design intents,and the result of a user survey are presented,which highlights how EvoMass and the performance-based design optimization and exploration can enable architects to achieve a more performance-aware design.
文摘The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of risk substances(including local anesthetics,LAs)in cosmetics,which has been successfully applied in the analysis of actual samples.This work aims to develop a more convenient high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS/MS)method for the quantitative determination of LAs.Samples were ultrasonically extracted with methanol,separated on an Agilent Poroshell 120 EC-C18 column(2.1 mm×100 mm,2.7μm),and eluted with a gradient mobile phase consisting of 0.1%formic acid aqueous solution and methanol.Quantification was performed using the external standard method.The results show that all 23 LAs are effectively separated within 12 minutes,with good linearity in the corresponding concentration ranges and the correlation coefficients all greater than 0.99.The limits of detection(LOD)range from 0.0025 to 0.05μg/g,and the limits of quantification(LOQ)range from 0.01 to 0.1μg/g.The average recoveries of the 23 LAs in 5 blank cosmetic matrices are 80.68%-117.57%,with the relative standard deviations(RSDs)less than 5.98%.This method has good precision and high accuracy,and is suitable for the determination of LAs in 5 cosmetic matrices.
基金Supported by National Natural Science Foundation of China(No.82101113).
文摘Dear Editor,Ciliary body masses are diagnostically challenging due to their hidden location,diverse pathologies,and limited examination methods[1].We report a case of a ciliary body inflammatory mass treated with trans-scleral excision and antiinflammatory therapy,preserving functional vision.
基金Natural Science Basic Research Program of Shaanxi Province,Grant/Award Number:2023-YBGY-085National Natural Science Foundation of China,Grant/Award Numbers:41902277,42172302Fundamental Research Funds for the Central Universities,Grant/Award Number:CHD.300102282201。
文摘The vibration caused by blasting excavation of rock mass frequently poses a threat to the stability of adjacent tunnels.Previous research is limited by the simplification of a rock mass as a homogeneous elastic medium,without considering the wave attenuation caused by viscoelasticity and wave separation induced by rock discontinuities,as well as plane waves while neglecting geometric attenuation of near-field nonplane blast waves.This paper establishes a theoretical model of cylindrical P-wave propagation across a fault to an adjacent existing tunnel.Based on the time-domain recursive method,vibration equations and peak particle velocity on the adjacent existing tunnel wall caused by a cylindrical wave passing through a fault are derived.The rock mass and fault are assumed to satisfy Kelvin viscoelastic bodies,and contact interfaces between fault and rock mass follow a nonlinear hyperbolic deformation model in the normal direction and a linear model in the tangential direction.The results show that tunnel vibration caused by the blast cylindrical P-wave is primarily induced by transmitted P-waves.With the increase of the fault dip angle,vibration on the upper side of the adjacent existing tunnel gradually decreases,while vibration on the lower side increases.The closer the vibration to the upper and lower sides,the stronger the shear effect on the tunnel wall,and the closer the vibration to the middle,the stronger the pressure effect on the tunnel wall.Larger fault thickness and higher initial blast wave frequency result in weaker vibration of the adjacent tunnel.The deeper the burial depth,the stronger the vibration of the adjacent tunnel wall.Findings of this study provide insight into the dynamic response of rock construction and safety evaluation in engineering service.
基金Project supported by the National Natural Science Foundation of China(52074031,51574213,51904027)the Fundamental Research Funds for the Central Universities of China(06500104)。
文摘Understanding the underlying mechanism that enhances the separation of specific target ions from complex background aqueous solutions is crucial for achieving controllable chemical reactions and industrial purification processes in modern industries.This study investigated the enhanced kinetic separatio n of target metal ions from complex aqueous solutio ns at a liquid-liquid interface,focusing on the presence of coexisting salt cations.Employing a typical thin-layer organic oil film(TOOF)extraction as a model system,the research examines how background Al^(3+)ions influence the mass transfer and separation of ions.Notably,the co ncentration of Al^(3+)ions affects both the distribution of Er^(3+)ions at the oil-water interface and the arrangement and orientation of P507 extractant molecules through the formation of unique hydrogen-bonding interactions.These interactions influence the selectivity of mass transfer,facilitating the separation of Er^(3+)from Al^(3+)ions.Specifically,the hydration shell of Er^(3+)ions is disrupted due to the strong hydration capability of coexisting Al^(3+)ions,leading to a higher interfacial concentration of Er^(3+)ions and a more ordered interfacial orientation of P507 molecules.At lower concentrations of Al^(3+)ions,the diffusion rate of Er^(3+)ions near the interface is high,enhancing the sepa ration perfo rmance of these ions.In contrast,at higher concentrations of Al^(3+)ions,the competitive hydration by Al^(3+)ions increases,and the interfacial concentration of Er^(3+)ions decreases due to enhanced diffusion resistance,resulting in poorer separation performance.Furthermore,a thinner membrane is more effective than a thicker one in enriching target Er^(3+)ions at the interface and achieving an ordered interfacial orientation of P507 molecules,thereby enhancing the separation coefficient(β_(Er/Al)).This work provides novel insights into the behaviors of ions and extractants at oil-wate r interface and the kinetic separation selectivity under varying concentrations of coexisting salt cations.
基金the National Key Research and Development Program of China(2022YFE0208400)the Shanxi Province Key Research and Development Program(202202090301002)the Natural Science Foundation of Shanxi Province,China(202103021224096).
文摘This study investigates catalytic tar cracking over semi-coke catalysts,addressing reaction kinetics challenges by integrating experimental data with a COMSOL Multiphysics model.A multi-physics framework combines catalysis,carbon deposition,and self-consumption to analyze toluene(tar model compound)removal.The model evaluates intrinsic catalytic activity,porosity evolution,and porous media flow,revealing that toluene conversion is governed by diffusion/convective mass transfer,homogeneous reactions,and surface reactions influenced by dynamic carbon deposition/removal.Increasing temperature from 973 to 1173 K enhances gas-film heat and mass transfer coefficient,accelerating tar cracking rates and extending catalyst lifetime.Elevated temperatures improve gas-solid phase heat/mass transfer,promoting efficient tar removal during syngas purification.The results highlight the interplay between reaction kinetics,carbon deposition dynamics,and transport phenomena in optimizing semi-coke catalyst performance under high-temperature conditions.
基金Supported by the National Natural Science Foundation of China(No.82501261)Medical Research Projects of the Jiangsu Provincial Health Commission(No.M2024041).
文摘AIM:To investigate the causal effect of obesity on cataract risk and explores the potential mediating roles of metabolites using Mendelian randomization(MR).METHODS:Summary-level data from large-scale genome-wide association studies to examine the relationship between obesity and cataract were utilized.Obesity-related traits,including body mass index(BMI),waist-to-hip ratio(WHR),and waist circumference(WC).A two-sample MR approach was employed to assess the causal effect of obesity on cataract risk,while potential mediators were identified from suitable genome-wide association studies(GWAS)datasets.Additionally,a metabolic pathway analysis was conducted.RESULTS:An increase of 1 standard deviation(SD)in BMI,WHR,and WC was associated with a significantly higher risk of cataract(BMI:odds ratio(OR)1.0017,95%confidence interval(CI):1.0001-1.0032,P=0.0320;WHR:OR 1.0029,95%CI:1.0006-1.0051,P=0.0129;WC:OR 1.0020,95%CI:1.0001-1.0038,P=0.0390].These associations remained robust after adjusting for confounding factors in multivariable MR analysis.Furthermore,a two-step MR analysis identified eight potential metabolic mediators,with one mediator showing a significant causal role in the relationship between obesity and cataract.CONCLUSION:This work highlights the importance of addressing obesity as a modifiable risk factor for cataracts,particularly through metabolic pathways.
基金supported this work,but the SMP acknowledges support from the Canada Research Chairs Program(CRC-2021-00495)MJL is supported by a Canadian Institutes of Health Research(CIHR)Postdoctoral Fellowship award(Funding Reference No.187773).
文摘Mechanical tension is widely recognized as the primary stimulus underlying the molecular mechanisms that influence muscle hypertrophy induced by resistance training.Despite this,several outdated or overstated concepts continue to persist,both in the scientific literature and in the practical application of resistance training coaching and program design.Claims that acute hormonal responses,metabolic stress,cell swelling or“the pump”meaningfully contribute to hypertrophy are not supported by scientific evidence.Additionally,the concept of sarcoplasmic hypertrophy as a distinct and functionally meaningful contributor to hypertrophy lacks strong evidence.In this review,we critically evaluate several persistent misconceptions and contrast them with evidence-based mechanistic insights into load-induced hypertrophy.Specifically,we discuss the role(or lack thereof)of systemic hormones,metabolites,and cell swelling in promoting muscle hypertrophy.We also critically review the concept of sarcoplasmic hypertrophy and propose that it is not a meaningful contributor to muscle hypertrophy.Lastly,to translate knowledge for trainees and coaches,we discuss the upper limit of muscle hypertrophy and provide readers with evidence-based,reasonable expectations for muscle hypertrophy.We aimed,through this review,to use scientific evidence to enhance our understanding of what drives muscle hypertrophy and provide an evidence-based framework for resistance exercise training.
基金supported by the National Key R&D Plan“Inter-governmental International Science&Technology Innovation Cooperation”Key Specialized Program,China(2025YFE0102800)the Program of the State Key Laboratory of Cryospheric Science and Frozen Soil Engineering,Chinese Academy of Sciences(CSFSE-ZZ-2403).
文摘Tajikistan contains the majority of Central Asia’s glaciers,which cover about 6.00%of the national territory;their rapid shrinkage poses a significant threat to regional water resource security.However,glacier monitoring in Tajikistan was interrupted after 1991,creating a substantial gap in understanding the current state and temporal evolution of these glaciers.Based on glacier inventory data,in situ measurements,and published literature,this study examined the present status and recent variations of glaciers in Tajikistan through data integration and validation,literature collation and comparative analysis,and the application of Geographic Information System(GIS)spatial analysis techniques.As of 2023,Tajikistan possesses a total of 11,528 glaciers,encompassing an area of 7624.48(±305.58)km2.Small glaciers dominate in number,whereas large glaciers account for the majority of the total area.Over the past two decades,the glacier count has decreased by 2014,and the total area has decreased by 628.98 km2,corresponding to an average annual reduction rate of 0.33%.Regional shrinkage rates range from 4.10%to 22.28%.Glaciers have undergone accelerated mass loss during the past 20 a;only those on the northeastern Pamir Plateau exhibit a weak positive mass balance.Observations of typical monitored glaciers also reveal intensified melting and retreat,consistent with regional trends.In light of the recent acceleration of glacier shrinkage in Tajikistan,focused measures should be implemented to strengthen glacier monitoring,enhance public awareness of glacier preservation,and promote the sustainable development and utilization of glacier tourism.These findings bridge the knowledge gap regarding the spatiotemporal dynamics of Tajikistan’s glaciers over recent decades and provide essential data support for regional water resource management.
基金primarily supported by the National Key Research and Development Program of China(Grant No.2024YFD1501201-3)partially supported by the National Key Research and Development Program of China(Grant No.2021YFD1500700)。
文摘Mass wasting is globally recognized as a key geomorphic agent in permanent gully expansion and greatly contributes to watershed sediment losses.Though its formation process has been assessed by some physical models,the occurrence and rainfall threshold have been rarely documented.In this study,rainfall-induced mass wasting events in two permanent gullies located in the Mollisols region of Northeast China,with Mollisols(gully 1)and sandy soil(gully 2)underneath were observed,and their differences were explored based on their soil strengths,hydraulic properties,excess topographies,and theoretical rainfall amounts.The sandy soil had a higher strength,faster pore water pressure dissipation rate,and lower suction stress at a specific soil moisture content compared to the black soil.The erosion thickness of the gully bed and sidewalls in gully 1 was shallower compared to gully 2.This was confirmed by the relationship between the erosion thickness and excess topography.The differences in the mass wasting erosion of the gully bed and sidewalls were due to the higher shear strength and well-drained hydraulic properties of the sandy soil compared to the black-soil.An infinite model was chosen to examine the temporal order of the mass wasting in the two gullies.It was found that the mass wasting in gully 2 occurred earlier than that in gully 1.This was likely due to the occurrence of an intense storm with less rainfall at the location of gully 2,while a light storm with heavier rainfall occurred in the location of gully 1.As Mollisols and sandy soil are the typical soil horizons in the Mollisols region worldwide,the results of this work could provide insightful knowledge for understanding the physical process of permanent gully expansion,which may be helpful for developing prediction models for sediment losses in some watersheds with vast Mollisols and highly developed gully system.
基金supported by the open project of the theoretical physics academic exchange platform of Chongqing University。
文摘For loops with UV divergences,assuming that the physical contributions of loops from UV regions are insignificant,a UV-free scheme method described by an equation is introduced to derive loop results without UV divergences in the calculations,i.e.,a route of the analytic continuation T_(F)→T_(P)besides the traditional route∞-∞in the mathematical structure.This scheme provides a new perspective to an open question of the hierarchy problem of Higgs mass,i.e.,an alternative interpretation without fine-tuning within the standard model.
基金supported by the MUSC-TU Scholarship for Human Resource Development in Science & Technology in the Remembrance of Late King Rama Ⅸ of ThailandPartial Funding for Graduate Student Thesis for the Year 2021 by the Faculty of Graduate Studies and Graduate Studies of Mahidol University Alumni Association。
文摘Background: Post-workout supplementation has been used in athletes and recreational exercisers;however, responses between normal and overweight individuals on exercise performance and muscle recovery are less known.Methods: Normal and overweight young adult males(21 subjects/group) participated in resistance and fatiguing exercises before receiving post-workout supplements: placebo, coenzyme Q10(CoQ10), or sports drink in a crossover design. Resistance exercises included upper body exercise(bench press, upright row, and standing shoulder press) and lower body exercise(dead lift, back squat, and front squat) at 75% of one-repetition maximum(1 RM). Fatiguing exercise was performed on a cycle ergometer with 3 min of all-out effort at 3.5% of body mass. Participants consumed post-workout supplements within 10 min of exercise completion and repeated-bout exercise was performed 1 h later, followed by cardiovascular responses, urinary biomarkers, and delayed onset muscle soreness(DOMS) assessments.Results: There were effects of overweight on resistance exercise volume, critical power, fatigue index, and postexercise diastolic blood pressure(DBP). However, no differences in urinary biomarkers of muscle damage(potassium and creatinine) or DOMS between normal and overweight individuals. After supplementation, CoQ10 and sports drink increased resistance exercise volume regardless of body mass and increased critical power in the normal group. Additionally, CoQ10 supplementation was associated with a reduction in urinary biomarkers and DOMS in both groups.Conclusion: These findings are beneficial for sport scientists, nutritionists, and exercise physiologists in guiding post-workout supplementation with CoQ10 and sports drink to improve exercise performance and muscle recovery in normal and overweight individuals.
基金supported by the State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering(Grant No.SDGZ2505)the Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation(Grant No.GZB20250742)the General Program of the China Postdoctoral Science Foundation(Grant No.2025M773213).
文摘The negative Poisson’s ratio(NPR)bolt is an innovative support element distinguished by its high strength,elongation,and a slightly negative Poisson’s ratio.Unlike conventional prestressed(PR)bolts with a positive Poisson’s ratio,the NPR bolt exhibits a quasi-ideal plastic response without a prominent yield platform,enabling it to sustain high prestress with a substantial safety margin,which is particularly advantageous for jointed rock masses.However,investigations into the shear resistance mechanisms of NPR bolts under varying prestress levels remain limited.This study conducted full-scale double shear tests to assess the shear strength,deformation behavior,energy absorption,and failure mechanisms of NPR bolts under different prestress conditions.To ensure a fair comparison with PR bolts,a prestress utilization coefficient(PUC)was introduced.The results reveal that at a PUC of 0.25,the NPR bolt achieved peak axial force,shear displacement,and peak shear force values that are 2.41,1.88,and 2.13 times greater than those of the PR bolt,respectively.Shear performance was optimized at a prestress level of 100 kN,with energy absorption reaching 47.1 kJ,which is 2.8 times that of the PR bolt.Furthermore,the necking ratio was significantly reduced,indicating more distributed plastic deformation and delayed failure.Field applications verified the superior performance,resulting in a 27.4%reduction in roof settlement and enhanced structural integrity.These findings confirm that NPR bolts possess excellent shear resistance,energy absorption,and deformation adaptability,and optimizing prestress significantly enhances their support performance,providing a strong basis for geotechnical engineering applications.
基金supported by the National Natural Science Foundation of China(No.52001142)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘The corrosion wear behavior of the selective laser melting(SLM)and forged TC4 alloys in 3.5 wt.%NaCl solution is studied.Results indicate that the current densities of the two TC4 alloys increase with the increase in applied potential,meaning that the corrosion resistance of the alloys decreases.And the main product of the passive film is TiO_(2).What’s more,corrosion wear behavior is more severe due to the presence of corrosion,resulting in greater mass losses and deeper wear scars.To explore the interaction between corrosion and wear for the two TC4 alloys,the change of the mass loss proportions for wear caused by corrosion and corrosion caused by wear with potential is analyzed.The mass loss of wear caused by corrosion cannot be ignored,and it affects SLM TC4 alloy with the unique acicularα′-phase significantly.
基金supported by the Yanzhao Gold Talent Project of Hebei Province(NO.HJZD202506)。
文摘Objective Previous studies link lower body mass index(BMI)with increased obsessive-compulsive disorder(OCD)risk,yet other body mass indicators may be more etioloically relevant.We dissected the causal association between body fat mass(FM)and OCD.Methods Summary statistics from genome-wide association studies of European ancestry were utilized to conduct two-sample Mendelian randomization analysis.Heterogeneity,horizontal pleiotropy,and sensitivity analyses were performed to assess the robustness.Results The inverse variance weighting method demonstrated that a genetically predicted decrease in FM was causally associated with an increased OCD risk[odds ratio(OR)=0.680,95%confidence interval(CI):0.528–0.875,P=0.003].Similar estimates were obtained using the weighted median approach(OR=0.633,95%CI:0.438–0.915,P=0.015).Each standard deviation increases in genetically predicted body fat percentage corresponded to a reduced OCD risk(OR=0.638,95%CI:0.455–0.896,P=0.009).The sensitivity analysis confirmed the robustness of these findings with no outlier instrument variables identified.Conclusion The negative causal association between FM and the risk of OCD suggests that the prevention or treatment of mental disorders should include not only the control of BMI but also fat distribution and body composition.
