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 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 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
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
In this paper, I show that the Special Relativistic effect of mass increase that occurs within objects when they move at high speed can be explained using Classical Physics principles. In my analysis, the wave nature ...In this paper, I show that the Special Relativistic effect of mass increase that occurs within objects when they move at high speed can be explained using Classical Physics principles. In my analysis, the wave nature of condensed matter and energy/mass equivalence are taken into consideration. The wave nature of particles is modelled as the particle structure comprising three-dimensional standing waves. When this is done, the difference in the energy sum of the component waves that comprise a particle moving at a high speed, when compared to those of a stationary particle, completely accounts for the mass increase. Furthermore, the additional momentum of the wave components in the direction of motion (the Longitudinal direction) is the cause of the inertia, or effective mass, of the object being greater than that in the Transverse direction (orthogonal to the direction of motion).展开更多
Flow around the front pillar of an automobile is typical of a flow field with separated and reattached flow by a vortex system. It is known that the vortex system causes the greatest aerodynamic sound around a vehicle...Flow around the front pillar of an automobile is typical of a flow field with separated and reattached flow by a vortex system. It is known that the vortex system causes the greatest aerodynamic sound around a vehicle. The objective of the present study is to clarify the relationship between vortical structures and aerodynamic sound by the vortex system generated around the front pillar. The vortex system consists of the longitudinal and the transverse system. The characteristics of the longitudinal vortex system were investigated in comparison with the transverse one. Two vortex systems were reproduced by three-dimensional delta wings. The flow visualization experiment and the computational fluid dynamics (CFD) captured well the characteristics of the flow structure of the two vortex systems. These results showed that the longitudinal with the rotating axis along mean flow direction had cone-shaped configuration whereas the transverse with the rotating axis vertical to mean flow direction had elliptic one. Increasing the tip angles of the wings from 40 to 140 degrees, there first exists the longitudinal vortex system less than 110 degrees, with the transition region ranging from 110 to 120 degrees, and finally over 120 degrees the transverse appears. The characteristics of aerodynamic sound radiated from the two vortex systems were investigated in low Mach numbers, high Reynolds number turbulent flows in the lownoise wind tunnel. As a result, it was found that the aerodynamic sound radiated from both the longitudinal and the transverse vortex system was proportional to the fifth from sixth power of mean flow velocity, and that the longitudinal vortex generated the aerodynamic sound larger than the transverse.展开更多
The phase diagrams and the other crtical properties of S-3/2 Ising model in random longitudinal and transverse fields(RLIM) are dicussed with the approximate scheme combined by mean-field renormalization group theory(...The phase diagrams and the other crtical properties of S-3/2 Ising model in random longitudinal and transverse fields(RLIM) are dicussed with the approximate scheme combined by mean-field renormalization group theory(MFRG) and the discretized path-integral representation(DPIR).展开更多
The dynamic response of pile in layered soil is theoretically investigated when considering the transverse inertia effect.Firstly, the fictitious soil-pile model is employed to simulate the dynamic interaction between...The dynamic response of pile in layered soil is theoretically investigated when considering the transverse inertia effect.Firstly, the fictitious soil-pile model is employed to simulate the dynamic interaction between the pile and the soil layers beneath pile toe. The dynamic interactions of adjacent soil layers along the vertical direction are simplified as distributed Voigt models.Meanwhile, the pile and fictitious soil-pile are assumed to be viscoelastic Rayleigh-Love rods, and both the radial and vertical displacement continuity conditions at the soil-pile interface are taken into consideration. On this basis, the analytical solution for dynamic response at the pile head is derived in the frequency domain and the corresponding quasi-analytical solution in the time domain is then obtained by means of the convolution theorem. Following this, the accuracy and parameter value of the hypothetical boundaries for soil-layer interfaces are discussed. Comparisons with published solution and measured data are carried out to verify the rationality of the present solution. Parametric analyses are further conducted by using the present solution to investigate the relationships between the transverse inertia effects and soil-pile parameters.展开更多
In this paper, it is discussed that two tests for varying dispersion of binomial data in the framework of nonlinear logistic models with random effects, which are widely used in analyzing longitudinal binomial data. O...In this paper, it is discussed that two tests for varying dispersion of binomial data in the framework of nonlinear logistic models with random effects, which are widely used in analyzing longitudinal binomial data. One is the individual test and power calculation for varying dispersion through testing the randomness of cluster effects, which is extensions of Dean(1992) and Commenges et al (1994). The second test is the composite test for varying dispersion through simultaneously testing the randomness of cluster effects and the equality of random-effect means. The score test statistics are constructed and expressed in simple, easy to use, matrix formulas. The authors illustrate their test methods using the insecticide data (Giltinan, Capizzi & Malani (1988)).展开更多
The nonlinear space charge effect of bunched beam in linac is one of the important factors thatinduces the emittance growth due to the conversion of the field energy to kinetic energy.In this paper,us-ing a cylinder m...The nonlinear space charge effect of bunched beam in linac is one of the important factors thatinduces the emittance growth due to the conversion of the field energy to kinetic energy.In this paper,us-ing a cylinder model of space charge in linac,we derived the internal energy for a bunched beam withsome nonuniform space charge distributions,such as longitudinal Gaussian distribution combined withKapchinskij-Vladimirski1,waterbag,parabolic or Gaussian transverse distribution.And the emittancegrowth caused by the above distributions is worked out.展开更多
Four turbulence models, namely, the basic and nonlinear stress-transport models and the basic and anisotropic k- epsilon models, have been tested in the case of interaction between a longitudinal vortex pair and a fla...Four turbulence models, namely, the basic and nonlinear stress-transport models and the basic and anisotropic k- epsilon models, have been tested in the case of interaction between a longitudinal vortex pair and a flat-plate boundary layer. The results of their predictions were compared with Mehta and Bradshaw's measurements. Part of the results involving those of the nonlinear stress-transport model and anisotropic k- epsilon model are presented and discussed. (Edited author abstract) 13 Refs.展开更多
The compact,sensitive,and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging.The metasurface offers a promising solution to develop h...The compact,sensitive,and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging.The metasurface offers a promising solution to develop high-precision displacement metrology.In this work,we proposed and experimentally demonstrated a two-dimensional displacement(XZ)measurement device by a dielectric metasurface.Both transversal and longitudinal displacements of the metasurface can be obtained by the analysis of the interference optical intensity that is generated by the deflected light beams while the metasurface is under linearly polarized incidence.We experimentally demonstrated that displacements down to 5.4 nm along the x-axis and 0.12μm along the z-axis can be resolved with a 900μm×900μm metasurface.Our work opens up new possibilities to develop a compact high-precision multidimensional displacement sensor.展开更多
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.
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 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.
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.
文摘In this paper, I show that the Special Relativistic effect of mass increase that occurs within objects when they move at high speed can be explained using Classical Physics principles. In my analysis, the wave nature of condensed matter and energy/mass equivalence are taken into consideration. The wave nature of particles is modelled as the particle structure comprising three-dimensional standing waves. When this is done, the difference in the energy sum of the component waves that comprise a particle moving at a high speed, when compared to those of a stationary particle, completely accounts for the mass increase. Furthermore, the additional momentum of the wave components in the direction of motion (the Longitudinal direction) is the cause of the inertia, or effective mass, of the object being greater than that in the Transverse direction (orthogonal to the direction of motion).
文摘Flow around the front pillar of an automobile is typical of a flow field with separated and reattached flow by a vortex system. It is known that the vortex system causes the greatest aerodynamic sound around a vehicle. The objective of the present study is to clarify the relationship between vortical structures and aerodynamic sound by the vortex system generated around the front pillar. The vortex system consists of the longitudinal and the transverse system. The characteristics of the longitudinal vortex system were investigated in comparison with the transverse one. Two vortex systems were reproduced by three-dimensional delta wings. The flow visualization experiment and the computational fluid dynamics (CFD) captured well the characteristics of the flow structure of the two vortex systems. These results showed that the longitudinal with the rotating axis along mean flow direction had cone-shaped configuration whereas the transverse with the rotating axis vertical to mean flow direction had elliptic one. Increasing the tip angles of the wings from 40 to 140 degrees, there first exists the longitudinal vortex system less than 110 degrees, with the transition region ranging from 110 to 120 degrees, and finally over 120 degrees the transverse appears. The characteristics of aerodynamic sound radiated from the two vortex systems were investigated in low Mach numbers, high Reynolds number turbulent flows in the lownoise wind tunnel. As a result, it was found that the aerodynamic sound radiated from both the longitudinal and the transverse vortex system was proportional to the fifth from sixth power of mean flow velocity, and that the longitudinal vortex generated the aerodynamic sound larger than the transverse.
文摘The phase diagrams and the other crtical properties of S-3/2 Ising model in random longitudinal and transverse fields(RLIM) are dicussed with the approximate scheme combined by mean-field renormalization group theory(MFRG) and the discretized path-integral representation(DPIR).
基金Projects(51378464,51309207)supported by the National Natural Science Foundation of China
文摘The dynamic response of pile in layered soil is theoretically investigated when considering the transverse inertia effect.Firstly, the fictitious soil-pile model is employed to simulate the dynamic interaction between the pile and the soil layers beneath pile toe. The dynamic interactions of adjacent soil layers along the vertical direction are simplified as distributed Voigt models.Meanwhile, the pile and fictitious soil-pile are assumed to be viscoelastic Rayleigh-Love rods, and both the radial and vertical displacement continuity conditions at the soil-pile interface are taken into consideration. On this basis, the analytical solution for dynamic response at the pile head is derived in the frequency domain and the corresponding quasi-analytical solution in the time domain is then obtained by means of the convolution theorem. Following this, the accuracy and parameter value of the hypothetical boundaries for soil-layer interfaces are discussed. Comparisons with published solution and measured data are carried out to verify the rationality of the present solution. Parametric analyses are further conducted by using the present solution to investigate the relationships between the transverse inertia effects and soil-pile parameters.
基金The project supported by NNSFC (19631040), NSSFC (04BTJ002) and the grant for post-doctor fellows in SELF.
文摘In this paper, it is discussed that two tests for varying dispersion of binomial data in the framework of nonlinear logistic models with random effects, which are widely used in analyzing longitudinal binomial data. One is the individual test and power calculation for varying dispersion through testing the randomness of cluster effects, which is extensions of Dean(1992) and Commenges et al (1994). The second test is the composite test for varying dispersion through simultaneously testing the randomness of cluster effects and the equality of random-effect means. The score test statistics are constructed and expressed in simple, easy to use, matrix formulas. The authors illustrate their test methods using the insecticide data (Giltinan, Capizzi & Malani (1988)).
基金The project supported by the National Natural Science Foundation of China and the Sciences Foundation of Chinese Nuclear Industry
文摘The nonlinear space charge effect of bunched beam in linac is one of the important factors thatinduces the emittance growth due to the conversion of the field energy to kinetic energy.In this paper,us-ing a cylinder model of space charge in linac,we derived the internal energy for a bunched beam withsome nonuniform space charge distributions,such as longitudinal Gaussian distribution combined withKapchinskij-Vladimirski1,waterbag,parabolic or Gaussian transverse distribution.And the emittancegrowth caused by the above distributions is worked out.
基金The project supported by the National Natural Science Foundation of China under Contract No.19132012
文摘Four turbulence models, namely, the basic and nonlinear stress-transport models and the basic and anisotropic k- epsilon models, have been tested in the case of interaction between a longitudinal vortex pair and a flat-plate boundary layer. The results of their predictions were compared with Mehta and Bradshaw's measurements. Part of the results involving those of the nonlinear stress-transport model and anisotropic k- epsilon model are presented and discussed. (Edited author abstract) 13 Refs.
基金supported by the National Natural Science Foundation of China(No.U20A20216)the Technology Domain Fund of 173 Project(No.2021-JCJQ-JJ-0284)。
文摘The compact,sensitive,and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging.The metasurface offers a promising solution to develop high-precision displacement metrology.In this work,we proposed and experimentally demonstrated a two-dimensional displacement(XZ)measurement device by a dielectric metasurface.Both transversal and longitudinal displacements of the metasurface can be obtained by the analysis of the interference optical intensity that is generated by the deflected light beams while the metasurface is under linearly polarized incidence.We experimentally demonstrated that displacements down to 5.4 nm along the x-axis and 0.12μm along the z-axis can be resolved with a 900μm×900μm metasurface.Our work opens up new possibilities to develop a compact high-precision multidimensional displacement sensor.