In this study,three specific scenarios of a novel accelerator light source mechanism called steady-state microbunching(SSMB)were studied:longitudinal weak focusing,longitudinal strong focusing,and generalized longitud...In this study,three specific scenarios of a novel accelerator light source mechanism called steady-state microbunching(SSMB)were studied:longitudinal weak focusing,longitudinal strong focusing,and generalized longitudinal strong focusing(GLSF).At present,GLSF is the most promising method for realizing high-power short-wavelength coherent radiation with mild requirements on modulation laser power.Its essence is to exploit the ultrasmall natural vertical emittance of an electron beam in a planar storage ring for efficient microbunching formation,like a partial transverse-longitudinal emittance exchange in the optical laser wavelength range.Based on an in-depth investigation of related beam physics,a solution for a GLSF SSMB storage ring that can deliver 1 kW average-power EUV light is presented.The work in this paper,such as the generalized Courant–Snyder formalism,analysis of theoretical minimum emittances,transverse-longitudinal coupling dynamics,and derivation of the bunching factor and modulation strengths for laser-induced microbunching schemes,is expected to be useful not only for the development of SSMB but also for future accelerator light sources in general that demand increasingly precise electron beam phase space manipulations.展开更多
The transverse incision with longitudinal ligation(TILL)procedure is a new method for treating circumferential prolapsed hemorrhoids.A study by Song et al found TILL to be better than the traditional Milligan-Morgan h...The transverse incision with longitudinal ligation(TILL)procedure is a new method for treating circumferential prolapsed hemorrhoids.A study by Song et al found TILL to be better than the traditional Milligan-Morgan hemorrhoidectomy for short-term results,showing less pain,quicker healing,and lower risk of anal stenosis.TILL reduces tissue tension and controls blood supply,allowing effective removal of diseased tissue while maintaining anal function and structure.However,the study's limitations,including its retrospective,single-center design,small sample size,and short follow-up,restrict the findings'generalizability and ability to assess long-term outcomes like recurrence.Larger,multicenter trials are needed for a thorough evaluation and wider clinical adoption of TILL.展开更多
BACKGROUND Circumferential prolapsed hemorrhoids(CPHs)necessitate surgical intervention.While Milligan-Morgan hemorrhoidectomy(MMH)remains widely used,it compromises functional preservation and associates with signifi...BACKGROUND Circumferential prolapsed hemorrhoids(CPHs)necessitate surgical intervention.While Milligan-Morgan hemorrhoidectomy(MMH)remains widely used,it compromises functional preservation and associates with significant post-operative pain,edema,and delayed healing in severe CPH cases.To address these limitations,our research team innovatively proposed the transverse incision with longitudinal ligation procedure(TILL).This novel technique utilizes targeted transverse incisions and longitudinal pedicle ligation to optimize complete resection while preserving anal anatomy and function.METHODS A total of 180 patients were retrospectively reviewed in China.The patients were divided into two groups of 90 based on the surgical methods.The treatment group underwent the TILL procedure,while the control group underwent MMH.The main observation index was the evaluation of clinical efficacy after wound healing.Secondary outcomes included the recurrence rate and wound healing time.Safety measurements were also evaluated.RESULTS The TILL group showed a significant difference compared to the MMH group(P=0.022),indicating better overall treatment effects.The time for wound healing in the TILL group was shorter than that in the MMH group(P=0.001).Compared to those who underwent MMH,those who underwent TILL experienced significantly reduced postoperative pain,with lower average scores for anal edema and anal stenosis(both P<0.05).CONCLUSION TILL demonstrates superior efficacy to MMH for advanced CPH,reducing recovery times and postoperative pain,edema,and stenosis while preserving anal function.展开更多
The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,...The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,despite the fact that the scenario exists in practice.A series of laboratory-scale experiments were conducted in this study to investigate the smoke back-layering length in a model tunnel with cross-passage.The heat release rate,the velocity of longitudinal air flow,and the location of the fire source were all varied.It was found that the behavior of smoke backflow for the fire source located at the upstream of bifurcation point resembles a single-hole tunnel fire.As the fire source’s position shifts downstream from the bifurcation point,the length of smoke back-layering progressively increases.A competitive interaction exists between airflow diversion and smoke diversion during smoke backflow,significantly affecting the smoke back-layering length in the main tunnel.The dimensionless smoke back-layering length model was formulated in a tunnel featuring a cross-passage,taking into account the positions of longitudinal fire sources.The dimensionless smoke back-layering length exhibits a positive correlation with the 17/18 power of total heat release rate Q and a negative correlation with the 5/2 power of longitudinal ventilation velocity V.展开更多
This study explores the core characteristics,dynamic progression of the depression-anxiety-stress network among Chinese higher vocational college freshmen and its association with life satisfaction,and identifies key ...This study explores the core characteristics,dynamic progression of the depression-anxiety-stress network among Chinese higher vocational college freshmen and its association with life satisfaction,and identifies key nodes and critical intervention points.Participants were 295 higher vocational college freshmen(male=137;M=18.52,SD=0.69)completing two follow-up surveys(5-month interval).Measures included depression-anxiety-stress symptoms and life satisfaction,analyzed via cross-sectional and binary cross-lagged panel network analysis.The results showed that“Easily agitated”was the central node(strength=1.519,EI=1.967);“Irritable”and“Mouth Dryness”were top predictors(Out-EI=1.101,1.100),with depressive symptoms as the convergence hub.“Easily agitated”had the strongest direct negative impact on life satisfaction(cross-cluster out-predictability=−0.653).This study elucidates depression-anxietystress network mechanisms in higher vocational freshmen,providing a theoretical framework and targeted intervention guidance(e.g.,focusing on somatic and emotional nodes).展开更多
Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analyt...Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.展开更多
Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section...Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate.展开更多
The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal-field is studied within the mean-field theory based on Bogoliubov inequality for the Gibbs free energy. The ground-state phase diagram and th...The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal-field is studied within the mean-field theory based on Bogoliubov inequality for the Gibbs free energy. The ground-state phase diagram and the tricritical point are obtained in the transverse field Ω/ zJ-longitudinal crystal D / zJ field plane. We find that there are the first order-order phase transitions in a very small range of D /zJ besides the usual first order-disorder phase transitions and the second order-disorder phase transitions,展开更多
The spin-1 Blume–Capel model with transverse and longitudinal external magnetic fields h, in addition to a longitudinal random crystal field D, is studied in the mean-field approximation. It is assumed that the cryst...The spin-1 Blume–Capel model with transverse and longitudinal external magnetic fields h, in addition to a longitudinal random crystal field D, is studied in the mean-field approximation. It is assumed that the crystal field is either turned on with probability p or turned off with probability 1 p on the sites of a square lattice. Phase diagrams are then calculated on the reduced temperature crystal field planes for given values of γ=Ω/J and p at zero h. Thus, the effect of changing γ and p are illustrated on the phase diagrams in great detail and interesting results are observed.展开更多
The transverse permeability ratio (TPR) and longitudinal permeability ratio (LPR) as a function of an external field of mumetal films have been investigated in conjunction with the magnetic properties. The mumetal fil...The transverse permeability ratio (TPR) and longitudinal permeability ratio (LPR) as a function of an external field of mumetal films have been investigated in conjunction with the magnetic properties. The mumetal films were prepared by the R.F.magnetron sputtering method in Ar atmosphere. The LPR curve shows the single peak pattern, and the TPR curve shows the double peak pattern indicating the existence of the magnetic anisotropy effect. The magnitude of the incremental permeability are strongly depended on the magnetic softness. The large changes of LPR and TPR in low external fields can be useful for the evaluation of the magnetic softness.展开更多
Uric acid is reduced in demyelinating diseases, including multiple sclerosis and neuromyelitis optica （NMO）. Longitudinally extensive transverse myelitis （LETM） is often an early manifestation of NMO. Whether uric...Uric acid is reduced in demyelinating diseases, including multiple sclerosis and neuromyelitis optica （NMO）. Longitudinally extensive transverse myelitis （LETM） is often an early manifestation of NMO. Whether uric acid levels are reduced at presentation of LETM remains unknown. The present study investigated serum uric acid levels by evaluating 35 patients with LETM, 64 with NMO, 62 with multiple sclerosis, 63 with other neurological diseases and 65 healthy controls. In addition, we tested the correlation between serum uric acid and the clinical characteristics of LETM. All patients were in the acute phase, defined as less than 1 month from onset or relapse. The results revealed that serum uric acid levels in LETM were significantly lower than in multiple sclerosis, other neurological diseases and healthy controls, but no difference was found between LETM and NMO. A negative correlation between uric acid levels and Expanded Disability Status Scale scores was found in LETM patients （r = -0.545, P 〈 0.05）. The results suggest that uric acid levels are reduced in patients with LETM, raising the possibility that lower uric acid levels are an indicator of disease disability. Moreover, reduced uric acid levels may be a risk factor in NMO.展开更多
Four kinds of Au nanorods（NRs）with different aspect ratios are designed to adjust the relationship between resonance energy level of longitudinal（L）and transverse（T）modes.During the femto-second Z-scan experimen...Four kinds of Au nanorods（NRs）with different aspect ratios are designed to adjust the relationship between resonance energy level of longitudinal（L）and transverse（T）modes.During the femto-second Z-scan experiments,huge saturable absorption phenomena are observed while the energy level T is located between one to two times of the energylevel L.This means that the energy may transfer between longitudinal and transverse energylevels in the same and/or different Au NRs.It effectively depresses the production of revised saturated absorption and increases the saturable absorption efficiency.This method is significant for the preparation of high-efficiency saturable absorption devices.展开更多
Spontaneous phasic contractions of detrusor smooth muscle are pivotal to the normal bladder filling process. The role of K+ channels in mediating phasic contractions has been investigated on different occasions, but o...Spontaneous phasic contractions of detrusor smooth muscle are pivotal to the normal bladder filling process. The role of K+ channels in mediating phasic contractions has been investigated on different occasions, but only in detrusor strips isolated longitudinally. In this study, the effects of individual K+ blockers were examined in both transverse and longitudinal detrusor strips. Detrusor strips were isolated transversely and longitudinally from young adult rat bladders. Tension before and after the introduction of K+channel blockers was measured using a myograph. Phasic activity was determined by calculating the integral of tension fluctuations. Phasic activity of transverse strips was increased under tetraethylammonium chloride (TEA), 4-aminopyridine (4-AP) and iberiotoxin (IbTx) treatments. Longitudinal phasic activity was increased under charybdotoxin (ChTx) treatment. Neither glibenclamide (Glib) nor apamin treatment elicited any significant effect in both transverse and longitudinal phasic activity. The results indicated that phasic activity was mediated differently depending on the contractile direction. Data from this study reiterate that in addition to the conventional longitudinal direction, the transverse direction also presents significance when examining the contractility of a sac-like organ like the bladder.展开更多
Transmitting a longitudinal wave and a traverse wave into a composite material in a molten state has been studied in the online control of the composite material which cannot be evaluated by a conventional ultrasonic ...Transmitting a longitudinal wave and a traverse wave into a composite material in a molten state has been studied in the online control of the composite material which cannot be evaluated by a conventional ultrasonic sensor as a final analysis, using the difference in the propagation characteristics of both modes. It is especially expected that measurement of the physical quantity which was not able to be conventionally measured can be performed by carrying out coincidence measurement of the ultrasonic wave in both modes. Therefore, in this research study, an ultrasonic probe, which can simultaneously transmit and receive a longitudinal wave and a traverse wave has been developed using an electromagnetic acoustic transducer (EMAT) because it has the advantage of measuring high temperature samples. In this study, two methods have been compared. The 1st method uses a traverse wave EMAT that travels in a vertical direction and a bar wave by which the low order mode is equivalent to longitudinal wave vibration. The other method is to carry out the mode conversion of the traverse wave by a traverse wave-EMAT. The longitudinal converted from the transverse wave are spread in the axis direction. As the experimental results of both optimizations of the drive conditions, it has been confirmed that the 2nd mode conversion method was promising. This paper reports about the trial process and the experimental results.展开更多
This paper presents a new ultrasonic NDT technique for measuring the thicknessof a nonmetal material(called the ciadding material)with low sound velocity which iscladded on the one side of a thin metal plate(called th...This paper presents a new ultrasonic NDT technique for measuring the thicknessof a nonmetal material(called the ciadding material)with low sound velocity which iscladded on the one side of a thin metal plate(called the base)with high sound velocity such as tubes,tins and other closed containers,testing and inspecting the unglued area betweenthem,detecting the inner defect of the compesite from the side of the base in case that themeasurement and inspection has to be carried out on the side of the base.The principle ofthe technique is that a longitudinal or transverse wave induced by the pulse Lamb wave inthe base is transmited in certam direction into the compounded material,then reflected bythe upper and lower boundary of the compounded material.The same mode pulse Lambwave is formed while the longitudinal or transverse wave in the compounded material returnthe base.展开更多
Streamwise evolution of longitudinal and transverse velocity structure functions in a decaying homogeneous and nearly isotropic turbulence is reported for Reynolds numbers Reλ up to 720. First, two theoretical relati...Streamwise evolution of longitudinal and transverse velocity structure functions in a decaying homogeneous and nearly isotropic turbulence is reported for Reynolds numbers Reλ up to 720. First, two theoretical relations between longitudinal and transverse structure functions are examined in the light of recently derived relations and the results show that the low-order transverse structure functions can be well approximated by longitudinal ones within the sub-inertial range. Reconstruction of fourth-order transverse structure functions with a recently proposed relation by Grauer et al. is comparatively less valid than the relation already proposed by Antonia et al. Secondly, extended self-similarity methods are used to measure the scaling exponents up to order eight and the streamwise evolution of scaling exponents is explored. The scaling exponents of longitudinal structure functions are, at first location, close to Zybin's model, and at the fourth location, close to She–Leveque model. No obvious trend is found for the streamwise evolution of longitudinal scaling exponents, whereas, on the contrary, transverse scaling exponents become slightly smaller with the development of a steamwise direction. Finally, the stremwise variation of the order-dependent isotropy ratio indicates the turbulence at the last location is closer to isotropic than the other three locations.展开更多
Rationale:Longitudinally extensive transverse myelitis(LETM)is a rare inflammatory demyelinating disease predominantly associated with autoimmune and inflammatory disorders.Scrub typhus can cause a variety of neurolog...Rationale:Longitudinally extensive transverse myelitis(LETM)is a rare inflammatory demyelinating disease predominantly associated with autoimmune and inflammatory disorders.Scrub typhus can cause a variety of neurological complications,which may result in poor recovery and long-term disability.This report reveals a rare linkage between LETM and scrub typhus.Patient concerns:A 24-year-old female presented with a history of fever for 10 days associated with progressive quadriparesis.Physical examination revealed bilateral lower limb weakness(grade 0/5)and bilateral upper limb weakness(grade 2/5)with reduced sensation below the T3 dermatome.Diagnosis:Scrub typhus presenting with longitudinally extensive transverse myelitis.Interventions:Steroid pulse therapy with antibiotics supported by early intensive rehabilitation.Outcomes:Complete recovery was achieved.Lessons:This case report highlights the importance of considering scrub typhus as a potential cause of LETM in endemic regions,particularly in patients presenting with febrile illness and neurological symptoms.展开更多
Transverse mode-coupling instability(TMCI)is a dangerous transverse single-bunch instability that can lead to severe par-ticle loss.The mechanism of TMCI can be explained by the coupling of transverse coherent oscilla...Transverse mode-coupling instability(TMCI)is a dangerous transverse single-bunch instability that can lead to severe par-ticle loss.The mechanism of TMCI can be explained by the coupling of transverse coherent oscillation modes owing to the transverse short-range wakefield(i.e.,the transverse broadband impedance).Recent studies on future circular colliders,e.g.,FCC-ee,showed that the threshold of TMCI decreased significantly when both longitudinal and transverse impedances were included.We performed computations for the circular electron-positron collider(CEPC)and observed a similar phenom-enon.Systematic studies on the influence of longitudinal impedance on the TMCI threshold were conducted.We concluded that the imaginary part of the longitudinal impedance,which caused a reduction in the incoherent synchrotron tune,was the primary reason for the reduction in the TMCI threshold.Additionally,the real part of the longitudinal impedance assists in increasing the TMCI threshold.展开更多
The nonlinear space charge effect of bunched beam with nonuniform densitydistribution in both longitudinal and transverse directions is discussed.Some usefulformulae are derived for calculating the potential induced b...The nonlinear space charge effect of bunched beam with nonuniform densitydistribution in both longitudinal and transverse directions is discussed.Some usefulformulae are derived for calculating the potential induced by a cylinder model of spacecharge in the waveguide of a linac with longitudinal density distributions of waterbag(WB) or parabolic (PA) type combining with transverse density distributions ofKapchinskij-Vladimirskij (K-V).waterbag,parabolic and Gaussian (GA) types,resepectively.展开更多
The nonlinear space charge effect of bunched beam in linac is one of theimportant factors that induces the emittance growth due to the conversion of thefield energy to kinetic energy. Using a cylinder model of space c...The nonlinear space charge effect of bunched beam in linac is one of theimportant factors that induces the emittance growth due to the conversion of thefield energy to kinetic energy. Using a cylinder model of space charge in a linac,we derive the internal energy for a bunched beam with some nonuniform spacecharge distributions, such as Gaussian, waterbag and parabolic distributions inboth the longitudinal and transverse directions. And the emittance growth causedby these nonuniformities is worked out.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1603401)National Natural Science Foundation of China(Nos.12035010 and 12342501)+1 种基金Beijing Outstanding Young Scientist Program(No.JWZQ20240101006)the Tsinghua University Dushi Program.
文摘In this study,three specific scenarios of a novel accelerator light source mechanism called steady-state microbunching(SSMB)were studied:longitudinal weak focusing,longitudinal strong focusing,and generalized longitudinal strong focusing(GLSF).At present,GLSF is the most promising method for realizing high-power short-wavelength coherent radiation with mild requirements on modulation laser power.Its essence is to exploit the ultrasmall natural vertical emittance of an electron beam in a planar storage ring for efficient microbunching formation,like a partial transverse-longitudinal emittance exchange in the optical laser wavelength range.Based on an in-depth investigation of related beam physics,a solution for a GLSF SSMB storage ring that can deliver 1 kW average-power EUV light is presented.The work in this paper,such as the generalized Courant–Snyder formalism,analysis of theoretical minimum emittances,transverse-longitudinal coupling dynamics,and derivation of the bunching factor and modulation strengths for laser-induced microbunching schemes,is expected to be useful not only for the development of SSMB but also for future accelerator light sources in general that demand increasingly precise electron beam phase space manipulations.
文摘The transverse incision with longitudinal ligation(TILL)procedure is a new method for treating circumferential prolapsed hemorrhoids.A study by Song et al found TILL to be better than the traditional Milligan-Morgan hemorrhoidectomy for short-term results,showing less pain,quicker healing,and lower risk of anal stenosis.TILL reduces tissue tension and controls blood supply,allowing effective removal of diseased tissue while maintaining anal function and structure.However,the study's limitations,including its retrospective,single-center design,small sample size,and short follow-up,restrict the findings'generalizability and ability to assess long-term outcomes like recurrence.Larger,multicenter trials are needed for a thorough evaluation and wider clinical adoption of TILL.
基金Supported by Scientific Research Fund of China-Japan Friendship Hospital,No.2019-1-QN-53.
文摘BACKGROUND Circumferential prolapsed hemorrhoids(CPHs)necessitate surgical intervention.While Milligan-Morgan hemorrhoidectomy(MMH)remains widely used,it compromises functional preservation and associates with significant post-operative pain,edema,and delayed healing in severe CPH cases.To address these limitations,our research team innovatively proposed the transverse incision with longitudinal ligation procedure(TILL).This novel technique utilizes targeted transverse incisions and longitudinal pedicle ligation to optimize complete resection while preserving anal anatomy and function.METHODS A total of 180 patients were retrospectively reviewed in China.The patients were divided into two groups of 90 based on the surgical methods.The treatment group underwent the TILL procedure,while the control group underwent MMH.The main observation index was the evaluation of clinical efficacy after wound healing.Secondary outcomes included the recurrence rate and wound healing time.Safety measurements were also evaluated.RESULTS The TILL group showed a significant difference compared to the MMH group(P=0.022),indicating better overall treatment effects.The time for wound healing in the TILL group was shorter than that in the MMH group(P=0.001).Compared to those who underwent MMH,those who underwent TILL experienced significantly reduced postoperative pain,with lower average scores for anal edema and anal stenosis(both P<0.05).CONCLUSION TILL demonstrates superior efficacy to MMH for advanced CPH,reducing recovery times and postoperative pain,edema,and stenosis while preserving anal function.
基金funded by the National Natural Science Foundation of China(NSFC)under Grant No.52278415the National Key Research and Development Program of China under Grant No.2022YFC3801104+2 种基金Hebei Provincial Department of Education Project under Grant No.QN2025304the Innovation Fund Project of Hebei University of Engineering under Grant No.SJ2401002066the Sichuan Science and Technology Program under Grant No.2023YFS0407。
文摘The diversion effect caused by the linked structure in a metro tunnel with cross-passage complicates the impact of longitudinal fire source location on the smoke backflow layering behavior that has not been clarified,despite the fact that the scenario exists in practice.A series of laboratory-scale experiments were conducted in this study to investigate the smoke back-layering length in a model tunnel with cross-passage.The heat release rate,the velocity of longitudinal air flow,and the location of the fire source were all varied.It was found that the behavior of smoke backflow for the fire source located at the upstream of bifurcation point resembles a single-hole tunnel fire.As the fire source’s position shifts downstream from the bifurcation point,the length of smoke back-layering progressively increases.A competitive interaction exists between airflow diversion and smoke diversion during smoke backflow,significantly affecting the smoke back-layering length in the main tunnel.The dimensionless smoke back-layering length model was formulated in a tunnel featuring a cross-passage,taking into account the positions of longitudinal fire sources.The dimensionless smoke back-layering length exhibits a positive correlation with the 17/18 power of total heat release rate Q and a negative correlation with the 5/2 power of longitudinal ventilation velocity V.
基金supported by the Anhui Philosophical and Social Science Fund for University Research:The Application of Painting Psychological Analysis in College Students’Mental Health Education Courses(Grant#:2023AH052874),which has provided essential financial support for data collection.
文摘This study explores the core characteristics,dynamic progression of the depression-anxiety-stress network among Chinese higher vocational college freshmen and its association with life satisfaction,and identifies key nodes and critical intervention points.Participants were 295 higher vocational college freshmen(male=137;M=18.52,SD=0.69)completing two follow-up surveys(5-month interval).Measures included depression-anxiety-stress symptoms and life satisfaction,analyzed via cross-sectional and binary cross-lagged panel network analysis.The results showed that“Easily agitated”was the central node(strength=1.519,EI=1.967);“Irritable”and“Mouth Dryness”were top predictors(Out-EI=1.101,1.100),with depressive symptoms as the convergence hub.“Easily agitated”had the strongest direct negative impact on life satisfaction(cross-cluster out-predictability=−0.653).This study elucidates depression-anxietystress network mechanisms in higher vocational freshmen,providing a theoretical framework and targeted intervention guidance(e.g.,focusing on somatic and emotional nodes).
基金supported by the National Natural Science Foundation of China(No.41941018)Shanghai Gaofeng Discipline Construction Funding.
文摘Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.
基金financially supported by Youth Science“Research on Failure Mechanism and Evaluation Method of Sand Control Measures for Railway Machinery in Sandy Area”(12302511)Ningxia Transportation Department Science and Technology Project(20200173)The Central Guidance on Local Science and Technology Development Funds(22ZY1QA005)。
文摘Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate.
文摘The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal-field is studied within the mean-field theory based on Bogoliubov inequality for the Gibbs free energy. The ground-state phase diagram and the tricritical point are obtained in the transverse field Ω/ zJ-longitudinal crystal D / zJ field plane. We find that there are the first order-order phase transitions in a very small range of D /zJ besides the usual first order-disorder phase transitions and the second order-disorder phase transitions,
文摘The spin-1 Blume–Capel model with transverse and longitudinal external magnetic fields h, in addition to a longitudinal random crystal field D, is studied in the mean-field approximation. It is assumed that the crystal field is either turned on with probability p or turned off with probability 1 p on the sites of a square lattice. Phase diagrams are then calculated on the reduced temperature crystal field planes for given values of γ=Ω/J and p at zero h. Thus, the effect of changing γ and p are illustrated on the phase diagrams in great detail and interesting results are observed.
文摘The transverse permeability ratio (TPR) and longitudinal permeability ratio (LPR) as a function of an external field of mumetal films have been investigated in conjunction with the magnetic properties. The mumetal films were prepared by the R.F.magnetron sputtering method in Ar atmosphere. The LPR curve shows the single peak pattern, and the TPR curve shows the double peak pattern indicating the existence of the magnetic anisotropy effect. The magnitude of the incremental permeability are strongly depended on the magnetic softness. The large changes of LPR and TPR in low external fields can be useful for the evaluation of the magnetic softness.
基金the National Natural Science Foundation of China,No. 30971037
文摘Uric acid is reduced in demyelinating diseases, including multiple sclerosis and neuromyelitis optica （NMO）. Longitudinally extensive transverse myelitis （LETM） is often an early manifestation of NMO. Whether uric acid levels are reduced at presentation of LETM remains unknown. The present study investigated serum uric acid levels by evaluating 35 patients with LETM, 64 with NMO, 62 with multiple sclerosis, 63 with other neurological diseases and 65 healthy controls. In addition, we tested the correlation between serum uric acid and the clinical characteristics of LETM. All patients were in the acute phase, defined as less than 1 month from onset or relapse. The results revealed that serum uric acid levels in LETM were significantly lower than in multiple sclerosis, other neurological diseases and healthy controls, but no difference was found between LETM and NMO. A negative correlation between uric acid levels and Expanded Disability Status Scale scores was found in LETM patients （r = -0.545, P 〈 0.05）. The results suggest that uric acid levels are reduced in patients with LETM, raising the possibility that lower uric acid levels are an indicator of disease disability. Moreover, reduced uric acid levels may be a risk factor in NMO.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11404410 and 11504105the Hunan Provincial Natural Science Foundation under Grant No 2016JJ3140
文摘Four kinds of Au nanorods（NRs）with different aspect ratios are designed to adjust the relationship between resonance energy level of longitudinal（L）and transverse（T）modes.During the femto-second Z-scan experiments,huge saturable absorption phenomena are observed while the energy level T is located between one to two times of the energylevel L.This means that the energy may transfer between longitudinal and transverse energylevels in the same and/or different Au NRs.It effectively depresses the production of revised saturated absorption and increases the saturable absorption efficiency.This method is significant for the preparation of high-efficiency saturable absorption devices.
文摘Spontaneous phasic contractions of detrusor smooth muscle are pivotal to the normal bladder filling process. The role of K+ channels in mediating phasic contractions has been investigated on different occasions, but only in detrusor strips isolated longitudinally. In this study, the effects of individual K+ blockers were examined in both transverse and longitudinal detrusor strips. Detrusor strips were isolated transversely and longitudinally from young adult rat bladders. Tension before and after the introduction of K+channel blockers was measured using a myograph. Phasic activity was determined by calculating the integral of tension fluctuations. Phasic activity of transverse strips was increased under tetraethylammonium chloride (TEA), 4-aminopyridine (4-AP) and iberiotoxin (IbTx) treatments. Longitudinal phasic activity was increased under charybdotoxin (ChTx) treatment. Neither glibenclamide (Glib) nor apamin treatment elicited any significant effect in both transverse and longitudinal phasic activity. The results indicated that phasic activity was mediated differently depending on the contractile direction. Data from this study reiterate that in addition to the conventional longitudinal direction, the transverse direction also presents significance when examining the contractility of a sac-like organ like the bladder.
文摘Transmitting a longitudinal wave and a traverse wave into a composite material in a molten state has been studied in the online control of the composite material which cannot be evaluated by a conventional ultrasonic sensor as a final analysis, using the difference in the propagation characteristics of both modes. It is especially expected that measurement of the physical quantity which was not able to be conventionally measured can be performed by carrying out coincidence measurement of the ultrasonic wave in both modes. Therefore, in this research study, an ultrasonic probe, which can simultaneously transmit and receive a longitudinal wave and a traverse wave has been developed using an electromagnetic acoustic transducer (EMAT) because it has the advantage of measuring high temperature samples. In this study, two methods have been compared. The 1st method uses a traverse wave EMAT that travels in a vertical direction and a bar wave by which the low order mode is equivalent to longitudinal wave vibration. The other method is to carry out the mode conversion of the traverse wave by a traverse wave-EMAT. The longitudinal converted from the transverse wave are spread in the axis direction. As the experimental results of both optimizations of the drive conditions, it has been confirmed that the 2nd mode conversion method was promising. This paper reports about the trial process and the experimental results.
文摘This paper presents a new ultrasonic NDT technique for measuring the thicknessof a nonmetal material(called the ciadding material)with low sound velocity which iscladded on the one side of a thin metal plate(called the base)with high sound velocity such as tubes,tins and other closed containers,testing and inspecting the unglued area betweenthem,detecting the inner defect of the compesite from the side of the base in case that themeasurement and inspection has to be carried out on the side of the base.The principle ofthe technique is that a longitudinal or transverse wave induced by the pulse Lamb wave inthe base is transmited in certam direction into the compounded material,then reflected bythe upper and lower boundary of the compounded material.The same mode pulse Lambwave is formed while the longitudinal or transverse wave in the compounded material returnthe base.
基金Project supported by the National Natural Science Foundation of China （Grant Nos. 11272196, 11002085, and 11032007） and the Key Project of Education Commission of Shanghai Municipal, China （Grant No. 11ZZ87）.
文摘Streamwise evolution of longitudinal and transverse velocity structure functions in a decaying homogeneous and nearly isotropic turbulence is reported for Reynolds numbers Reλ up to 720. First, two theoretical relations between longitudinal and transverse structure functions are examined in the light of recently derived relations and the results show that the low-order transverse structure functions can be well approximated by longitudinal ones within the sub-inertial range. Reconstruction of fourth-order transverse structure functions with a recently proposed relation by Grauer et al. is comparatively less valid than the relation already proposed by Antonia et al. Secondly, extended self-similarity methods are used to measure the scaling exponents up to order eight and the streamwise evolution of scaling exponents is explored. The scaling exponents of longitudinal structure functions are, at first location, close to Zybin's model, and at the fourth location, close to She–Leveque model. No obvious trend is found for the streamwise evolution of longitudinal scaling exponents, whereas, on the contrary, transverse scaling exponents become slightly smaller with the development of a steamwise direction. Finally, the stremwise variation of the order-dependent isotropy ratio indicates the turbulence at the last location is closer to isotropic than the other three locations.
文摘Rationale:Longitudinally extensive transverse myelitis(LETM)is a rare inflammatory demyelinating disease predominantly associated with autoimmune and inflammatory disorders.Scrub typhus can cause a variety of neurological complications,which may result in poor recovery and long-term disability.This report reveals a rare linkage between LETM and scrub typhus.Patient concerns:A 24-year-old female presented with a history of fever for 10 days associated with progressive quadriparesis.Physical examination revealed bilateral lower limb weakness(grade 0/5)and bilateral upper limb weakness(grade 2/5)with reduced sensation below the T3 dermatome.Diagnosis:Scrub typhus presenting with longitudinally extensive transverse myelitis.Interventions:Steroid pulse therapy with antibiotics supported by early intensive rehabilitation.Outcomes:Complete recovery was achieved.Lessons:This case report highlights the importance of considering scrub typhus as a potential cause of LETM in endemic regions,particularly in patients presenting with febrile illness and neurological symptoms.
基金the National Natural Science Foundation of China(No.12375149)the National Key R&D Program of China(No.2022YFA1603401)the Innovation Study of the IHEP.
文摘Transverse mode-coupling instability(TMCI)is a dangerous transverse single-bunch instability that can lead to severe par-ticle loss.The mechanism of TMCI can be explained by the coupling of transverse coherent oscillation modes owing to the transverse short-range wakefield(i.e.,the transverse broadband impedance).Recent studies on future circular colliders,e.g.,FCC-ee,showed that the threshold of TMCI decreased significantly when both longitudinal and transverse impedances were included.We performed computations for the circular electron-positron collider(CEPC)and observed a similar phenom-enon.Systematic studies on the influence of longitudinal impedance on the TMCI threshold were conducted.We concluded that the imaginary part of the longitudinal impedance,which caused a reduction in the incoherent synchrotron tune,was the primary reason for the reduction in the TMCI threshold.Additionally,the real part of the longitudinal impedance assists in increasing the TMCI threshold.
基金the project supported by National Natural Science Foundation of ChinaNSFCChina Science Foundation of Nuclear Indusitry.
文摘The nonlinear space charge effect of bunched beam with nonuniform densitydistribution in both longitudinal and transverse directions is discussed.Some usefulformulae are derived for calculating the potential induced by a cylinder model of spacecharge in the waveguide of a linac with longitudinal density distributions of waterbag(WB) or parabolic (PA) type combining with transverse density distributions ofKapchinskij-Vladimirskij (K-V).waterbag,parabolic and Gaussian (GA) types,resepectively.
基金The project supported by the National Natural Science Foundation of China(NSFC) the Science Foundation of Chinese Nuclear Industry
文摘The nonlinear space charge effect of bunched beam in linac is one of theimportant factors that induces the emittance growth due to the conversion of thefield energy to kinetic energy. Using a cylinder model of space charge in a linac,we derive the internal energy for a bunched beam with some nonuniform spacecharge distributions, such as Gaussian, waterbag and parabolic distributions inboth the longitudinal and transverse directions. And the emittance growth causedby these nonuniformities is worked out.
