As a result of donor shortage and high postoperative morbidity and mortality after liver transplantation,hepatectomy is the most widely applicable and reliable option for curative treatment of hepatocellular carcinoma...As a result of donor shortage and high postoperative morbidity and mortality after liver transplantation,hepatectomy is the most widely applicable and reliable option for curative treatment of hepatocellular carcinoma(HCC).Because intrahepatic tumor recurrence is frequent after loco-regional therapy,repeated treatments are advocated provided background liver function is maintained.Among treatments including local ablation and transarterial chemoembolization,hepatectomy provides the best long-term outcomes,but studies comparing hepatectomy with other nonsurgical treatments require careful review for selection bias.In patients with initially unresectable HCC,transarterial chemo-or radio-embolization,and/or systemic chemotherapy can down-stage the tumor and conversion to resectable HCC is achieved in approximately 20%of patients.However,complete response is rare,and salvage hepatectomy is essential to help prolong patients’survival.To counter the short recurrence-free survival,excellent overall survival is obtained by combining and repeating different treatments.It is important to recognize hepatectomy as a complement,rather than a contraindication,to other nonsurgical treatments in a mul-tidisciplinary approach for patients with HCC,including recurrent or unresectable tumors.展开更多
Dear sir,Iam Dr.Wen-Wei Li,from the Department of Ophthalmology,Zhejiang Provincial People’s Hospital,Hangzhou,China.I write to present a case of ocular leech infestation initially misdiagnosed as conjunctival pigmen...Dear sir,Iam Dr.Wen-Wei Li,from the Department of Ophthalmology,Zhejiang Provincial People’s Hospital,Hangzhou,China.I write to present a case of ocular leech infestation initially misdiagnosed as conjunctival pigmented nevus.Although human interaction with leeches is not展开更多
The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach.It was found that under certain condition in two-photon Dicke model squeezi...The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach.It was found that under certain condition in two-photon Dicke model squeezing will be enhanced.The physical insight of this phenomenon is discussed.展开更多
Dear Sir, I am Dr. Jin Jiang, from the Department of Ophthalmology, Zhejiang Provincial People’s Hospital, Hangzhou, China. I write to present a peculiar case report of Phthiriasis palpebrarum initially misdiagnosed ...Dear Sir, I am Dr. Jin Jiang, from the Department of Ophthalmology, Zhejiang Provincial People’s Hospital, Hangzhou, China. I write to present a peculiar case report of Phthiriasis palpebrarum initially misdiagnosed as common blepharitis. Phthirus pubis (crab louse) infests mainly the hair of the pubic and inguinal regions,展开更多
Carbon fiber-reinforced plastic (CFRP) laminates with initially cut fibers (ICFs) have good formability without large degradation of static strength;however, their fatigue behavior has not been investigated thus far. ...Carbon fiber-reinforced plastic (CFRP) laminates with initially cut fibers (ICFs) have good formability without large degradation of static strength;however, their fatigue behavior has not been investigated thus far. In this paper, we investigated fatigue behavior and damage progress of open-holed CFRP laminates with ICFs having interlayers. Three types of CFRP laminates were employed: a laminate without ICF fabricated using an autoclave (Continuous-A), a laminate with ICF fabricated using an autoclave (ICF-A) and a laminate with ICF fabricated using press molding (ICF-P). First, fatigue test was conducted to obtain S (maximum stress)-N (the number of cycles to failure) curves in order to reveal fatigue strength. The fatigue tests for several specimens were interrupted at three prescribed numbers of cycles to observe damage progress. It is found that the Continuous-A laminate shows little strength degradation in the S-N curve while fatigue strength in both ICF laminates is decreased by approximately 30% at N of 106. In contrast, the damage progress of the ICF-P laminate is the least among the three laminates while the delamination progress at both edges and around the hole in the Continuous-A laminate is the most prominent.展开更多
A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis(CRLM),which involved the right hepatic vein(RHV)and the inferior vena cava(IVC),was referred to our hospital.The metastatic...A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis(CRLM),which involved the right hepatic vein(RHV)and the inferior vena cava(IVC),was referred to our hospital.The metastatic lesion was diagnosed as initially unresectable because of its invasion into the confluence of the RHV and IVC.After she had undergone laparoscopic sigmoidectomy for the original tumor,she consequently had 3 courses of modified 5-fluorouracil,leucovorin,and oxaliplatin(m FOLFOX6)plus cetuximab.Computed tomography revealed a partial response,and the confluence of the RHV and IVC got free from cancer invasion.After 3 additional courses of m FOLFOX6 plus cetuximab,preoperative percutaneous transhepatic portal vein embolization(PTPE)was performed to secure the future remnant liver volume.Finally,a right hemihepatectomy was performed.The postoperative course was uneventful.The patient was discharged from the hospital on postoperative day 13.She had neither local recurrence nor distant metastasis 18 mo after the last surgical intervention.This multidisciplinary strategy,consisting of conversion chemotherapy using FOLFOX plus cetuximab and PTPE,could contribute in facilitating curative hepatic resection for initially unresectable CRLM.展开更多
The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the speeds of plane waves. The appropriate solutions satisfy the required boundary conditions at the stress-free...The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the speeds of plane waves. The appropriate solutions satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflection coefficients of reflected quasi-P (qP) and quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter. The impact of initial stress parameter on the reflection coefficients is observed significantly.展开更多
The governing equations of an initially stressed rotating orthotropic dissipative medium are solved analytically to obtain the velocity equation which indicates the existence of two quasi-planar waves. The appropriate...The governing equations of an initially stressed rotating orthotropic dissipative medium are solved analytically to obtain the velocity equation which indicates the existence of two quasi-planar waves. The appropriate particular solutions in the half-space satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflec-tion coefficients of the reflected quasi-P (qP) and reflected quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter and rotation parameter. The impact of initial stress and rotation parameters on the reflection coefficients is observed significantly.展开更多
The present paper contributes in studying the phase velocities of P-and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratical...The present paper contributes in studying the phase velocities of P-and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratically along the depth. The dispersion equation is derived in a closed form. It is shown that the phase velocities depend not only on the initial stress, gravity, and direction of propagation but also on the inhomogeneity parameter associated with the density and acceleration due to gravity. Various particular cases are obtained, and the results match with the classical results. Numerical investigations on the phase velocities of P-and S-waves against the wave number are made for various sets of values of the material parameters, and the results are illustrated graphically. The graphical user interface model is developed to generalize the effect.展开更多
The bending of the Euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)theory.Although many models have been incorporated into the literature,there is still room for introdu...The bending of the Euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)theory.Although many models have been incorporated into the literature,there is still room for introducing an improved model in this context.In this work,we investigate the thermoelastic vibration of a micro-beam exposed to a varying temperature due to the application of the initial stress employing the MCS theory and generalized thermoelasticity.The MCS theory is used to investigate the material length scale effects.Using the Laplace transform,the temperature,deflection,displacement,flexure moment,and stress field variables of the micro-beam are derived.The effects of the temperature pulse and couple stress on the field distributions of the micro-beam are obtained numerically and graphically introduced.The numerical results indicate that the temperature pulse and couple stress have a significant effect on all field variables.展开更多
Unmanned aerial vehicles(UAVs),or drones,that were initially developed for military use during World War I[1],have evolved into highly sophisticated aircraft that can be navigated remotely using global positioning sys...Unmanned aerial vehicles(UAVs),or drones,that were initially developed for military use during World War I[1],have evolved into highly sophisticated aircraft that can be navigated remotely using global positioning systems.With constant improvements,drones have become more efficient,and cost-effective,with longer battery life and greater loading capacity.Today,UAVs have proven to be an effective and affordable solution for enhancing healthcare accessibility for patients who face geographical or infrastructural barriers.Using drone networks can greatly reduce the time transporting life-saving equipment,such as delivering automated external defibrillators(AEDs),to cardiac arrest victims,and can provide quick assistance to reduce travel time for the patients.展开更多
Worst business situation recorded in the survey.The global textile industry has been caught in a perfect storm for a long time,much longer that initially expected.This is true for all regions and all segments due to l...Worst business situation recorded in the survey.The global textile industry has been caught in a perfect storm for a long time,much longer that initially expected.This is true for all regions and all segments due to low demand and relatively high raw material and energy prices as well as higher interest rates and labour costs.展开更多
To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and thre...To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.展开更多
Neurons carry apical dendrites that perceive information and a basal axon that transmits the computed information towards its to rgets.The axon originates at the axon hillock which is followed by the axon initial segm...Neurons carry apical dendrites that perceive information and a basal axon that transmits the computed information towards its to rgets.The axon originates at the axon hillock which is followed by the axon initial segment.Here,action potentials are initiated that are based on millisecond long openings of specific voltagegated sodium and potassium channels that are conserved in all parahoxozoa(Placozoa,Cnidaria,Bilateria)(Li et al.,2015).展开更多
Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,...Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,respectively.In these processes,particles involved in the avalanche grow slowly in the early stage and explosively in the later stage,which is clearly different from the continuous and steady growth trend in the monodisperse system.By examining the avalanche propagation,the number growth of particles involved in the avalanche and the slope of the number growth,the initial state can be divided into three stages:T1(nucleation stage),T2(propagation stage),T3(overall avalanche stage).We focus on the characteristics of the avalanche in the T2 stage,and find that propagation distances increase almost linearly in both axial and radial directions in polydisperse systems.We also consider the distribution characteristics of the average coordination number and average velocity for the moving particles.The results support that the polydisperse particle systems are more stable in the T2 stage.展开更多
Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting pyrotechnics.To solve the problem,this research aims to reveal the ig...Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting pyrotechnics.To solve the problem,this research aims to reveal the ignition mechanism of EFIs directly igniting pyrotechnics.An oscilloscope,a photon Doppler velocimetry,and a plasma spectrum measurement system were employed to obtain information of electric characteristics,impact pressure,and plasma temperature.The results of the electric characteristics and the impact pressure were inconsistent with ignition results.The only thing that the ignition success tests had in common was that their plasma all had a relatively long period of high-temperature duration(HTD).It eventually concludes that the ignition mechanism in this research is the microconvection heat transfer rather than the shock initiation,which differs from that of exploding foil initiators detonating explosives.Furthermore,the methods for evaluating the ignition success of semiconductor bridge initiators are not entirely applicable to the tests mentioned in this paper.The HTD is the critical parameter for judging the ignition success,and it is influenced by two factors:the late time discharge and the energy of the electric explosion.The longer time of the late time discharge and the more energy of the electric explosion,the easier it is to expand the HTD,which improves the probability of the ignition success.展开更多
Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial pertur...Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.展开更多
Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the ...Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.展开更多
Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)an...Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.展开更多
基金Supported by Grant-in-aid from the 106~(th) Annual Congress of the JSS Memorial Surgical Research Fund,Tokyo,Japan
文摘As a result of donor shortage and high postoperative morbidity and mortality after liver transplantation,hepatectomy is the most widely applicable and reliable option for curative treatment of hepatocellular carcinoma(HCC).Because intrahepatic tumor recurrence is frequent after loco-regional therapy,repeated treatments are advocated provided background liver function is maintained.Among treatments including local ablation and transarterial chemoembolization,hepatectomy provides the best long-term outcomes,but studies comparing hepatectomy with other nonsurgical treatments require careful review for selection bias.In patients with initially unresectable HCC,transarterial chemo-or radio-embolization,and/or systemic chemotherapy can down-stage the tumor and conversion to resectable HCC is achieved in approximately 20%of patients.However,complete response is rare,and salvage hepatectomy is essential to help prolong patients’survival.To counter the short recurrence-free survival,excellent overall survival is obtained by combining and repeating different treatments.It is important to recognize hepatectomy as a complement,rather than a contraindication,to other nonsurgical treatments in a mul-tidisciplinary approach for patients with HCC,including recurrent or unresectable tumors.
文摘Dear sir,Iam Dr.Wen-Wei Li,from the Department of Ophthalmology,Zhejiang Provincial People’s Hospital,Hangzhou,China.I write to present a case of ocular leech infestation initially misdiagnosed as conjunctival pigmented nevus.Although human interaction with leeches is not
基金Supported by the National Natural Science Foundation of China.
文摘The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach.It was found that under certain condition in two-photon Dicke model squeezing will be enhanced.The physical insight of this phenomenon is discussed.
文摘Dear Sir, I am Dr. Jin Jiang, from the Department of Ophthalmology, Zhejiang Provincial People’s Hospital, Hangzhou, China. I write to present a peculiar case report of Phthiriasis palpebrarum initially misdiagnosed as common blepharitis. Phthirus pubis (crab louse) infests mainly the hair of the pubic and inguinal regions,
文摘Carbon fiber-reinforced plastic (CFRP) laminates with initially cut fibers (ICFs) have good formability without large degradation of static strength;however, their fatigue behavior has not been investigated thus far. In this paper, we investigated fatigue behavior and damage progress of open-holed CFRP laminates with ICFs having interlayers. Three types of CFRP laminates were employed: a laminate without ICF fabricated using an autoclave (Continuous-A), a laminate with ICF fabricated using an autoclave (ICF-A) and a laminate with ICF fabricated using press molding (ICF-P). First, fatigue test was conducted to obtain S (maximum stress)-N (the number of cycles to failure) curves in order to reveal fatigue strength. The fatigue tests for several specimens were interrupted at three prescribed numbers of cycles to observe damage progress. It is found that the Continuous-A laminate shows little strength degradation in the S-N curve while fatigue strength in both ICF laminates is decreased by approximately 30% at N of 106. In contrast, the damage progress of the ICF-P laminate is the least among the three laminates while the delamination progress at both edges and around the hole in the Continuous-A laminate is the most prominent.
文摘A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis(CRLM),which involved the right hepatic vein(RHV)and the inferior vena cava(IVC),was referred to our hospital.The metastatic lesion was diagnosed as initially unresectable because of its invasion into the confluence of the RHV and IVC.After she had undergone laparoscopic sigmoidectomy for the original tumor,she consequently had 3 courses of modified 5-fluorouracil,leucovorin,and oxaliplatin(m FOLFOX6)plus cetuximab.Computed tomography revealed a partial response,and the confluence of the RHV and IVC got free from cancer invasion.After 3 additional courses of m FOLFOX6 plus cetuximab,preoperative percutaneous transhepatic portal vein embolization(PTPE)was performed to secure the future remnant liver volume.Finally,a right hemihepatectomy was performed.The postoperative course was uneventful.The patient was discharged from the hospital on postoperative day 13.She had neither local recurrence nor distant metastasis 18 mo after the last surgical intervention.This multidisciplinary strategy,consisting of conversion chemotherapy using FOLFOX plus cetuximab and PTPE,could contribute in facilitating curative hepatic resection for initially unresectable CRLM.
文摘The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the speeds of plane waves. The appropriate solutions satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflection coefficients of reflected quasi-P (qP) and quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter. The impact of initial stress parameter on the reflection coefficients is observed significantly.
文摘The governing equations of an initially stressed rotating orthotropic dissipative medium are solved analytically to obtain the velocity equation which indicates the existence of two quasi-planar waves. The appropriate particular solutions in the half-space satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflec-tion coefficients of the reflected quasi-P (qP) and reflected quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter and rotation parameter. The impact of initial stress and rotation parameters on the reflection coefficients is observed significantly.
基金supported by the Research Fellow of Indian School of Mines in Dhanbad (No. 2010DR0016)
文摘The present paper contributes in studying the phase velocities of P-and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratically along the depth. The dispersion equation is derived in a closed form. It is shown that the phase velocities depend not only on the initial stress, gravity, and direction of propagation but also on the inhomogeneity parameter associated with the density and acceleration due to gravity. Various particular cases are obtained, and the results match with the classical results. Numerical investigations on the phase velocities of P-and S-waves against the wave number are made for various sets of values of the material parameters, and the results are illustrated graphically. The graphical user interface model is developed to generalize the effect.
文摘The bending of the Euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)theory.Although many models have been incorporated into the literature,there is still room for introducing an improved model in this context.In this work,we investigate the thermoelastic vibration of a micro-beam exposed to a varying temperature due to the application of the initial stress employing the MCS theory and generalized thermoelasticity.The MCS theory is used to investigate the material length scale effects.Using the Laplace transform,the temperature,deflection,displacement,flexure moment,and stress field variables of the micro-beam are derived.The effects of the temperature pulse and couple stress on the field distributions of the micro-beam are obtained numerically and graphically introduced.The numerical results indicate that the temperature pulse and couple stress have a significant effect on all field variables.
文摘Unmanned aerial vehicles(UAVs),or drones,that were initially developed for military use during World War I[1],have evolved into highly sophisticated aircraft that can be navigated remotely using global positioning systems.With constant improvements,drones have become more efficient,and cost-effective,with longer battery life and greater loading capacity.Today,UAVs have proven to be an effective and affordable solution for enhancing healthcare accessibility for patients who face geographical or infrastructural barriers.Using drone networks can greatly reduce the time transporting life-saving equipment,such as delivering automated external defibrillators(AEDs),to cardiac arrest victims,and can provide quick assistance to reduce travel time for the patients.
文摘Worst business situation recorded in the survey.The global textile industry has been caught in a perfect storm for a long time,much longer that initially expected.This is true for all regions and all segments due to low demand and relatively high raw material and energy prices as well as higher interest rates and labour costs.
基金supported by the National Natural Science Foundation of China (No.52204085)the Interdisciplinary Research Project for Young Teachers of USTB,Fundamental Research Funds for the Central Universities (No.FRF-IDRY-21-006).
文摘To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.
基金supported by the Deutsche Forschungsgemeinschaft through funds to CK(SFB1348,B5,KI 588/29)。
文摘Neurons carry apical dendrites that perceive information and a basal axon that transmits the computed information towards its to rgets.The axon originates at the axon hillock which is followed by the axon initial segment.Here,action potentials are initiated that are based on millisecond long openings of specific voltagegated sodium and potassium channels that are conserved in all parahoxozoa(Placozoa,Cnidaria,Bilateria)(Li et al.,2015).
基金Project supported by the Qingdao National Laboratory for Marine Science and Technology(Grant No.2015ASKJ01)the National Natural Science Foundation of China(Grant Nos.11972212,12072200,and 12002213).
文摘Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,respectively.In these processes,particles involved in the avalanche grow slowly in the early stage and explosively in the later stage,which is clearly different from the continuous and steady growth trend in the monodisperse system.By examining the avalanche propagation,the number growth of particles involved in the avalanche and the slope of the number growth,the initial state can be divided into three stages:T1(nucleation stage),T2(propagation stage),T3(overall avalanche stage).We focus on the characteristics of the avalanche in the T2 stage,and find that propagation distances increase almost linearly in both axial and radial directions in polydisperse systems.We also consider the distribution characteristics of the average coordination number and average velocity for the moving particles.The results support that the polydisperse particle systems are more stable in the T2 stage.
文摘Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting pyrotechnics.To solve the problem,this research aims to reveal the ignition mechanism of EFIs directly igniting pyrotechnics.An oscilloscope,a photon Doppler velocimetry,and a plasma spectrum measurement system were employed to obtain information of electric characteristics,impact pressure,and plasma temperature.The results of the electric characteristics and the impact pressure were inconsistent with ignition results.The only thing that the ignition success tests had in common was that their plasma all had a relatively long period of high-temperature duration(HTD).It eventually concludes that the ignition mechanism in this research is the microconvection heat transfer rather than the shock initiation,which differs from that of exploding foil initiators detonating explosives.Furthermore,the methods for evaluating the ignition success of semiconductor bridge initiators are not entirely applicable to the tests mentioned in this paper.The HTD is the critical parameter for judging the ignition success,and it is influenced by two factors:the late time discharge and the energy of the electric explosion.The longer time of the late time discharge and the more energy of the electric explosion,the easier it is to expand the HTD,which improves the probability of the ignition success.
基金supported by the Joint Funds of the Chinese National Natural Science Foundation (NSFC)(Grant No.U2242213)the National Key Research and Development (R&D)Program of the Ministry of Science and Technology of China(Grant No. 2021YFC3000902)the National Science Foundation for Young Scholars (Grant No. 42205166)。
文摘Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.
基金supported by National Natural Science Foundation of China(No.32270554 to CD)。
文摘Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.
基金the National Natural Science Foundation of China(Grant No.U20A2081)West Light Foundation of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202102)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Project(Grant No.2019QZKK0105).
文摘Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.
