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Failure transition of shear-to-dilation band of rock salt under triaxial stresses 被引量:2
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作者 Jianfeng Liu Xiaosong Qiu +3 位作者 Jianxiong Yang Chao Liang Jingjing Dai Yu Bian 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期56-64,共9页
Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily ... Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily or even hourly,which generates complicated pressures on the salt cavern.Furthermore,the mechanical behavior of rock salt may change and present distinct failure characteristics under different stress states,which affects the performance of salt cavern during the time period of full service.To reproduce a similar loading condition on the cavern surrounding rock mass,the cyclic triaxial loading/unloading tests are performed on the rock salt to explore the mechanical transition behavior and failure characteristics under different confinement.Experimental results show that the rock salt samples pre-sent a diffused shear failure band with significant bulges at certain locations in low confining pressure conditions(e.g.5 MPa,10 MPa and 15 MPa),which is closely related to crystal misorientation and grain boundary sliding.Under the elevated confinement(e.g.20 MPa,30 MPa and 40 MPa),the dilation band dominates the failure mechanism,where the large-size halite crystals are crushed to be smaller size and new pores are developing.The failure transition mechanism revealed in the paper provides additional insight into the mechanical performance of salt caverns influenced by complicated stress states. 展开更多
关键词 Rock salt Cyclic mechanical loading Shear band Dilation band Underground gas storage(UGS)
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Endoscopic polidocanol foam sclerobanding for the treatment of grade Ⅱ-Ⅲ internal hemorrhoids:A prospective,multi-center,randomized study 被引量:2
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作者 Chun-Ying Qu Fei-Yu Zhang +10 位作者 Yi Zhang Ming-Ming Li Zheng-Hong Li Mei-Hong Cai Lei-Ming Xu Feng Shen Wen Wang Wu-Lian Lin Feng-Yu Gao Hao Zhang Guang-Yu Chen 《World Journal of Gastroenterology》 SCIE CAS 2024年第27期3326-3335,共10页
BACKGROUND Endoscopic rubber band ligation(ERBL)is a nonsurgical technique for the treatment of symptomatic internal hemorrhoids but is limited by recurrence and post-procedural pain.AIM To evaluate satisfaction,long-... BACKGROUND Endoscopic rubber band ligation(ERBL)is a nonsurgical technique for the treatment of symptomatic internal hemorrhoids but is limited by recurrence and post-procedural pain.AIM To evaluate satisfaction,long-term recurrence,and post-procedural pain in managing internal hemorrhoids using a combination of polidocanol foam sclerotherapy and ERBL.METHODS This was a prospective,multicenter,randomized study.A total of 195 consecutive patients diagnosed with grade II-III internal hemorrhoids were enrolled from four tertiary hospitals and randomly divided into a cap-assisted endoscopic polidocanol foam sclerobanding(EFSB)or an ERBL group.All patients were followed-up for 12 months.Symptom-based severity and post-procedural pain were assessed using a hemorrhoid severity score(HSS)and a visual analog scale(VAS).Continuous variables were reported as medians and interquartile range.RESULTS One hundred and ninety-five patients were enrolled,with 98 in the EFSB group.HSS was lower in the EFSB group than in the ERBL group at 8 weeks[4.0(3.0-5.0)vs 5.0(4.0-6.0),P=0.003]and 12-month[2.0(1.0-3.0)vs 3.0(2.0-3.0),P<0.001]of follow-up.The prolapse recurrence rate was lower in the EFSB group at 12 months(11.2%vs 21.6%,P=0.038).Multiple linear regression analysis demonstrated that EFSB treatment[B=-0.915,95%confidence interval(CI):−1.301 to−0.530,P=0.001]and rubber band number(B=0.843,95%CI:0.595-1.092,P<0.001)were negatively and independently associated with the VAS score 24 hours post-procedure.The median VAS was lower in the EFSB group than in the ERBL[2.0(1.0-3.0)vs 3.0(2.0-4.0),P<0.001].CONCLUSION Cap-assisted EFSB provided long-term satisfaction and effective relief from the recurrence of prolapse and pain 24 hours post-procedure. 展开更多
关键词 Internal hemorrhoids Endoscopic therapy Polidocanol foam SCLEROTHERAPY Rubber band ligation Sclerobanding
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Ultra-wide band gap and wave attenuation mechanism of a novel star-shaped chiral metamaterial 被引量:1
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作者 Shuo WANG Anshuai WANG +7 位作者 Yansen WU Xiaofeng LI Yongtao SUN Zhaozhan ZHANG Qian DING G.D.AYALEW Yunxiang MA Qingyu LIN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第7期1261-1278,共18页
A novel hollow star-shaped chiral metamaterial(SCM)is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial,exhibiting a wide band gap over 1500 Hz.To broaden the ban... A novel hollow star-shaped chiral metamaterial(SCM)is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial,exhibiting a wide band gap over 1500 Hz.To broaden the band gap,solid single-phase and two-phase SCMs are designed and simulated,which produce two ultra-wide band gaps(approximately 5116 Hz and 6027 Hz,respectively).The main reason for the formation of the ultra-wide band gap is that the rotational vibration of the concave star of two novel SCMs drains the energy of an elastic wave.The impacts of the concave angle of a single-phase SCM and the resonator radius of a two-phase SCM on the band gaps are studied.Decreasing the concave angle leads to an increase in the width of the widest band gap,and the width of the widest band gap increases as the resonator radius of the two-phase SCM increases.Additionally,the study on elastic wave propagation characteristics involves analyzing frequency dispersion surfaces,wave propagation directions,group velocities,and phase velocities.Ultimately,the analysis focuses on the transmission properties of finite periodic structures.The solid single-phase SCM achieves a maximum vibration attenuation over 800,while the width of the band gap is smaller than that of the two-phase SCM.Both metamaterials exhibit high vibration attenuation capabilities,which can be used in wideband vibration reduction to satisfy the requirement of ultra-wide frequencies. 展开更多
关键词 METAMATERIAL ultra-wide band gap wave propagation vibration suppression
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Evaluation of the efficacy and safety of endoscopic band ligation in the treatment of bleeding from mild to moderate gastric varices type 1 被引量:2
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作者 Yue Deng Ya Jiang +4 位作者 Tong Jiang Ling Chen Hai-Jun Mou Bi-Guang Tuo Guo-Qing Shi 《World Journal of Gastroenterology》 SCIE CAS 2024年第5期440-449,共10页
BACKGROUND According to practice guidelines,endoscopic band ligation(EBL)and endoscopic tissue adhesive injection(TAI)are recommended for treating bleeding from esophagogastric varices.However,EBL and TAI are known to... BACKGROUND According to practice guidelines,endoscopic band ligation(EBL)and endoscopic tissue adhesive injection(TAI)are recommended for treating bleeding from esophagogastric varices.However,EBL and TAI are known to cause serious complications,such as hemorrhage from dislodged ligature rings caused by EBL and hemorrhage from operation-related ulcers resulting from TAI.However,the optimal therapy for mild to moderate type 1 gastric variceal hemorrhage(GOV1)has not been determined.Therefore,the aim of this study was to discover an individualized treatment for mild to moderate GOV1.AIM To compare the efficacy,safety and costs of EBL and TAI for the treatment of mild and moderate GOV1.METHODS A clinical analysis of the data retrieved from patients with mild or moderate GOV1 gastric varices who were treated under endoscopy was also conducted.Patients were allocated to an EBL group or an endoscopic TAI group.The differences in the incidence of varicose relief,operative time,operation success rate,mortality rate within 6 wk,rebleeding rate,6-wk operation-related ulcer healing rate,complication rate and average operation cost were compared between the two groups of patients.RESULTS The total effective rate of the two treatments was similar,but the efficacy of EBL(66.7%)was markedly better than that of TAI(39.2%)(P<0.05).The operation success rate in both groups was 100%,and the 6-wk mortality rate in both groups was 0%.The average operative time(26 min)in the EBL group was significantly shorter than that in the TAI group(46 min)(P<0.01).The rate of delayed postoperative rebleeding in the EBL group was significantly lower than that in the TAI group(11.8%vs 45.1%)(P<0.01).At 6 wk after the operation,the healing rate of operation-related ulcers in the EBL group was 80.4%,which was significantly greater than that in the TAI group(35.3%)(P<0.01).The incidence of postoperative complications in the two groups was similar.The average cost and other related economic factors were greater for the EBL than for the TAI(P<0.01).CONCLUSION For mild to moderate GOV1,patients with EBL had a greater one-time varix eradication rate,a greater 6-wk operation-related ulcer healing rate,a lower delayed rebleeding rate and a lower cost than patients with TAI. 展开更多
关键词 Gastric varices Type 1 gastric variceal hemorrhage Endoscopic band ligation Tissue adhesive injection
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Experimental observation of Fermi-level flat band in novel kagome metal CeNi_(5)
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作者 陈学智 王乐 +7 位作者 张帅 张任杰 程以伟 胡裕栋 孟承诺 刘正太 吕佰晴 黄耀波 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期467-472,共6页
Kagome materials are a class of material with a lattice structure composed of corner-sharing triangles that produce various exotic electronic phenomena,such as Dirac fermions,van Hove singularities,and flat bands.Howe... Kagome materials are a class of material with a lattice structure composed of corner-sharing triangles that produce various exotic electronic phenomena,such as Dirac fermions,van Hove singularities,and flat bands.However,most of the known kagome materials have a flat band detached from the Fermi energy,which limits the investigation of the emergent flat band physics.In this work,by combining soft x-ray angle-resolved photoemission spectroscopy(ARPES)and the first-principles calculations,the electronic structure is investigated of a novel kagome metal CeNi_(5) with a clear dispersion along the kz direction and a Fermi level flat band in theΓ–K–M–Γplane.Besides,resonant ARPES experimental results indicate that the valence state of Ce ions is close to 4^(+),which is consistent with the transport measurement result.Our results demonstrate the unique electronic properties of CeNi_(5) as a new kagome metal and provide an ideal platform for exploring the flat band physics and the interactions between different types of flat bands by tuning the valence state of Ce ions. 展开更多
关键词 ARPES kagome lattice band structure flat band
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Valence Bands Convergence in p-Type CoSb_(3) through Electronegative Fluorine Filling
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作者 黄写格 李家良 +5 位作者 马浩钦 李昌隆 刘天乐 段波 翟鹏程 李国栋 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第7期87-94,共8页
Band convergence is considered to be a strategy with clear benefits for thermoelectric performance,generally favoring the co-optimization of conductivity and Seebeck coefficients,and the conventional means include ele... Band convergence is considered to be a strategy with clear benefits for thermoelectric performance,generally favoring the co-optimization of conductivity and Seebeck coefficients,and the conventional means include elemental filling to regulate the band.However,the influence of the most electronegative fluorine on the CoSb_(3) band remains unclear.We carry out density-functional-theory calculations and show that the valence band maximum gradually shifts downward with the increase of fluorine filling,lastly the valence band maximum converges to the highly degenerated secondary valence bands in fluorine-filled skutterudites. 展开更多
关键词 VALENCE CONVERGENCE bandS
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A Narrowband Burst from FRB 20190520B Simultaneously Observed by FAST and Parkes
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作者 Yuhao Zhu Chenhui Niu +8 位作者 Shi Dai Di Li Pei Wang Yi Feng Jingwen Wu Yongkun Zhang Xianghan Cui Junshuo Zhang Jinhuang Cao 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第10期144-151,共8页
Fast radio bursts(FRBs)are short-duration radio transients with mysterious origins.Since their uncertainty,there are very few FRBs observed by different instruments simultaneously.This study presents a detailed analys... Fast radio bursts(FRBs)are short-duration radio transients with mysterious origins.Since their uncertainty,there are very few FRBs observed by different instruments simultaneously.This study presents a detailed analysis of a burst from FRB 20190520B observed by FAST and Parkes at the same time.The spectrum of this individual burst ended at the upper limit of the FAST frequency band and was simultaneously detected by the Parkes telescope in the 1.5–1.8GHz range.By employing spectral energy distribution(SED)and spectral sharpness methods,we confirmed the presence of narrow-band radiation in FRB 20190520B,which is crucial for understanding its radiation mechanisms.Our findings support the narrow-band characteristics that most repeaters exhibit.This work also highlights the necessity of continued multiband observations to explore its periodicity and frequency-dependent properties,contributing to an in-depth understanding of FRB phenomena. 展开更多
关键词 FAST NARROW band
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Behavior of exciton in direct−indirect band gap Al_(x)Ga_(1−x)As crystal lattice quantum wells
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作者 Yong Sun Wei Zhang +10 位作者 Shuang Han Ran An Xin-Sheng Tang Xin-Lei Yu Xiu-Juan Miao Xin-Jun Ma Xianglian Pei-Fang Li Cui-Lan Zhao Zhao-Hua Ding Jing-Lin Xiao 《Journal of Semiconductors》 EI CAS CSCD 2024年第3期64-70,共7页
Excitons have significant impacts on the properties of semiconductors.They exhibit significantly different properties when a direct semiconductor turns in to an indirect one by doping.Huybrecht variational method is a... Excitons have significant impacts on the properties of semiconductors.They exhibit significantly different properties when a direct semiconductor turns in to an indirect one by doping.Huybrecht variational method is also found to influence the study of exciton ground state energy and ground state binding energy in Al_(x)Ga_(1−x)As semiconductor spherical quantum dots.The Al_(x)Ga_(1−x)As is considered to be a direct semiconductor at AI concentration below 0.45,and an indirect one at the concentration above 0.45.With regards to the former,the ground state binding energy increases and decreases with AI concentration and eigenfrequency,respectively;however,while the ground state energy increases with AI concentration,it is marginally influenced by eigenfrequency.On the other hand,considering the latter,while the ground state binding energy increases with AI concentration,it decreases with eigenfrequency;nevertheless,the ground state energy increases both with AI concentration and eigenfrequency.Hence,for the better practical performance of the semiconductors,the properties of the excitons are suggested to vary by adjusting AI concentration and eigenfrequency. 展开更多
关键词 exciton effects aluminum gallium arsenide crystal direct band gap semiconductor indirect band gap semiconductor
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Layered kagome compound Na_(2)Ni_(3)S_(4)with topological flat band
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作者 叶君耀 林益浩 +4 位作者 王浩哲 宋志达 冯济 谢韦伟 贾爽 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期153-159,共7页
We report structural and electronic properties of Na_(2)Ni_(3)S_(4),a quasi-two-dimensional compound composed of alternating layers of[Ni_(3)S_(4)]^(2-)and Na^(+).The compound features a remarkable Ni-based kagome lat... We report structural and electronic properties of Na_(2)Ni_(3)S_(4),a quasi-two-dimensional compound composed of alternating layers of[Ni_(3)S_(4)]^(2-)and Na^(+).The compound features a remarkable Ni-based kagome lattice with a square planar configuration of four surrounding S atoms for each Ni atom.Magnetization and electrical measurements reveal a weak paramagnetic insulator with a gap of about 0.5 eV.Our band structure calculation highlights a set of topological flat bands of the kagome lattice derived from the rotated dxz-orbital with C_(3)+T symmetry in the presence of crystal-field splitting. 展开更多
关键词 kagome lattice flat band
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Numerical investigation of friction-heating-pressurization and its control parameters in the shear band of high-speed landslides
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作者 ZHAO Nenghao CUI Shenghua LU Haijun 《Journal of Mountain Science》 SCIE CSCD 2024年第10期3380-3395,共16页
High-speed sliding often leads to catastrophic landslides,many of which,in the initial sliding phase before disintegration,experience a friction-induced thermal pressurization effect in the bottom shear band,accelerat... High-speed sliding often leads to catastrophic landslides,many of which,in the initial sliding phase before disintegration,experience a friction-induced thermal pressurization effect in the bottom shear band,accelerating the movement of the overlying sliding mass.To quantitatively investigate this complex multiphysical phenomenon,we established a set of equations that describe the variations in temperature and excess pore pressure within the shear band,as well as the conservation of momentum equation for the overlying sliding mass.With a simplified landslide model,we investigated the variations of temperature and excess pore pressure within the shear band and their impacts on the velocity of the overlying sliding mass.On this basis,we studied the impact of seven key parameters on the maximum temperature and excess pore pressure in the shear band,as well as the impact on the velocity of the overlying sliding mass.The simulation results of the standard model show that the temperature and excess pore pressure in the shear band are significantly higher than those in the adjacent areas,and reach the maximum values in the center.Within a few seconds after the start,the maximum excess pore pressure in the shear zone is close to the initial stress,and the shear strength loss rate exceeds 90%.The thermal pressurization mechanism significantly increases the velocity of the overlying sliding mass.The results of parameter sensitivity analysis show that the thermal expansion coefficient has the most significant impact on the temperature and excess pore pressure in the shear band,and the sliding surface dip angle has the most significant impact on the velocity of the overlying sliding mass.The results of this study are of great significance for clarifying the mechanism of thermal pressurization-induced high-speed sliding. 展开更多
关键词 High-speed landslide Shear band Friction-heating-pressurization Numerical investigation
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Observation of parabolic electron bands on superconductor LaRu_(2)As_(2)
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作者 周兴泰 李更 +5 位作者 潘禄禄 陈子超 李萌 时延昊 杨海涛 高鸿钧 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期60-64,共5页
Ru-based superconductor LaRu_(2)As_(2) has been discovered exhibiting the highest critical temperature of ~ 7.8 K among iron-free transition metal pnictides with the ThCr_(2)Si_(2)-type crystal structure. However, mic... Ru-based superconductor LaRu_(2)As_(2) has been discovered exhibiting the highest critical temperature of ~ 7.8 K among iron-free transition metal pnictides with the ThCr_(2)Si_(2)-type crystal structure. However, microscopic research on this novel superconducting material is still lacking. Here, we utilize scanning tunneling microscopy/spectroscopy to uncover the superconductivity and surface structure of LaRu_(2)As_(2). Two distinct terminating surfaces are identified on the cleaved crystals, namely, the As surface and the La surface. Atomic missing line defects are observed on the La surface. Both surfaces exhibit a superconducting gap of ~ 1.0 me V. By employing quasiparticle interference techniques, we observe standing wave patterns near the line defects on the La atomic plane. These patterns are attributed to quasiparticle scattering from two electron type parabolic bands. 展开更多
关键词 SUPERCONDUCTIVITY line defect quasi-particle scattering electron band
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Band structures of strained kagome lattices
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作者 徐露婷 杨帆 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期456-463,共8页
Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices... Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices in response to uniaxial strain using both a tight-binding model and an antidot model based on a periodic muffin-tin potential.It is found that the Dirac points move with applied strain.Furthermore,the flat band of unstrained kagome lattices is found to develop into a highly anisotropic shape under a stretching strain along y direction,forming a partially flat band with a region dispersionless along ky direction while dispersive along kx direction.Our results shed light on the possibility of engineering the electronic band structures of kagome materials by mechanical strain. 展开更多
关键词 kagome lattice STRAIN band structure engineering
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Observation of flat-band localized state in a one-dimensional diamond momentum lattice of ultracold atoms
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作者 曾超 石悦然 +5 位作者 毛一屹 武菲菲 谢岩骏 苑涛 戴汉宁 陈宇翱 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期212-217,共6页
We investigated the one-dimensional diamond ladder in the momentum lattice platform. By inducing multiple twoand four-photon Bragg scatterings among specific momentum states, we achieved a flat band system based on th... We investigated the one-dimensional diamond ladder in the momentum lattice platform. By inducing multiple twoand four-photon Bragg scatterings among specific momentum states, we achieved a flat band system based on the diamond model, precisely controlling the coupling strength and phase between individual lattice sites. Utilizing two lattice sites couplings, we generated a compact localized state associated with the flat band, which remained localized throughout the entire time evolution. We successfully realized the continuous shift of flat bands by adjusting the corresponding nearest neighbor hopping strength, enabling us to observe the complete localization process. This opens avenues for further exploration of more complex properties within flat-band systems, including investigating the robustness of flat-band localized states in disordered flat-band systems and exploring many-body localization in interacting flat-band systems. 展开更多
关键词 diamond lattice flat band momentum lattice localized state
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Amniotic Band Syndrome at the Van Norman Clinic in Burundi: A Case Series
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作者 Alice Ndayishimiye Hélène Bukuru +4 位作者 Déogratias Niyungeko Anne Marie Nikuze Sylvestre Bazikamwe Jean Claude Mbonicura Gilbert Ndayizeye 《Surgical Science》 2024年第3期118-124,共7页
Amniotic band syndrome is an acquired embryo-fetopathy. It is rare and is characterized by malformations mainly affecting the limbs but also the skull, face and thoraco-abdominal axis. Its etiopathogenesis remains poo... Amniotic band syndrome is an acquired embryo-fetopathy. It is rare and is characterized by malformations mainly affecting the limbs but also the skull, face and thoraco-abdominal axis. Its etiopathogenesis remains poorly understood. Its diagnosis is essentially clinical and is classically based on the existence of signs such as furrows, amputations and pseudosyndactyly. To show the importance of antenatal diagnosis in resource-limited countries, we report the case of two newborns, one premature at 31 weeks and the other at term, in whom amniotic band syndrome was discovered incidentally at birth. It involved an amputation of the right leg for both cases. The premature baby was born in a context of neonatal sepsis and will succumb to the latter while the 2nd case was released from the hospital alive. Imaging examinations to search for probable congenital malformations could only be carried out for the 2nd case and no accessible congenital malformation had been identified. And as management of the disease, only psychological support to the parents was provided for the 2 cases. The antenatal discovery of a case of amniotic band syndrome in countries with low technical capacity such as Burundi should push clinicians to think in time about treatment options. 展开更多
关键词 Amniotic band Syndrome Embryo-Fetopathies Antenatal Diagnosis LIMBS
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Single crystal growth and transport properties of narrow-bandgap semiconductor RhP_(2)
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作者 吴德胜 郑萍 雒建林 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期545-549,共5页
We report the growth of high-quality single crystals of RhP_(2),and systematically study its structure and physical properties by transport,magnetism,and heat capacity measurements.Single-crystal x-ray diffraction rev... We report the growth of high-quality single crystals of RhP_(2),and systematically study its structure and physical properties by transport,magnetism,and heat capacity measurements.Single-crystal x-ray diffraction reveals that RhP_(2) adopts a monoclinic structure with the cell parameters a=5.7347(10)A,b=5.7804(11)A,and c=5.8222(11)A,space group P2_(1)/c(No.14).The electrical resistivityρ(T)measurements indicate that RhP_(2) exhibits narrow-bandgap behavior with the activation energies of 223.1 meV and 27.4 meV for two distinct regions,respectively.The temperaturedependent Hall effect measurements show electron domain transport behavior with a low charge carrier concentration.We find that RhP_(2) has a high mobilityμ_(e)~210 cm^(2)·V^(-1)·s^(-1)with carrier concentrations n_(e)~3.3×10^(18)cm^(3) at 300 K with a narrow-bandgap feature.The high mobilityμ_(e) reaches the maximum of approximately 340 cm^(2)·V^(-1)·s^(-1)with carrier concentrations n_^(e)~2×10^(18)cm^(-3)at 100 K.No magnetic phase transitions are observed from the susceptibilityχ(T)and specific heat C_(p)(T)measurements of RhP_(2).Our results not only provide effective potential as a material platform for studying exotic physical properties and electron band structures but also motivate further exploration of their potential photovoltaic and optoelectronic applications. 展开更多
关键词 single crystal growth narrow band system electrical transport high mobilities
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Optimal design for rubber concrete layered periodic foundations based on the analytical approximations of band gaps and mapping relations
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作者 Wu Qiaoyun Xu Zhifeng +2 位作者 Xu Peishan Zeng Wenxuan Chen Xuyong 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第3期593-608,共16页
The seismic performance of rubber concrete-layered periodic foundations are significantly influenced by their design,in which the band gaps play a paramount role.Aiming at providing better designs for these foundation... The seismic performance of rubber concrete-layered periodic foundations are significantly influenced by their design,in which the band gaps play a paramount role.Aiming at providing better designs for these foundations,this study first proposes and validates the analytical formulas to approximate the bounds of the first few band gaps.In addition,the mapping relations linking the frequencies of different band gaps are presented.Furthermore,an optimal design method for these foundations is developed,which is validated through an engineering example.It is demonstrated that ensuring the superstructure’s resonance zones are completely covered by the corresponding periodic foundation’s band gaps can achieve satisfactory vibration attenuation effects,which is a good strategy for the design of rubber concrete layered periodic foundations. 展开更多
关键词 periodic foundation band gap vibration attenuation seismic isolation optimal design
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Reanalysis of energy band structure in the type-II quantum wells
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作者 李欣欣 邓震 +4 位作者 江洋 杜春花 贾海强 王文新 陈弘 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期75-78,共4页
Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures... Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems. 展开更多
关键词 energy band structure type-II quantum wells low-dimensional semiconductors
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Endoscopic polidocanol foam sclerobanding for the treatment of Grade II-III internal hemorrhoids:The focus of clinical practice
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作者 Yu-Yan Zhang Bing Hu 《World Journal of Gastroenterology》 SCIE CAS 2024年第38期4246-4248,共3页
We have read the article by Qu et al with great interest,as it presents an inte-gration of endoscopic polidocanol foam sclerotherapy with rubber band ligation in patients with Grade II-III internal hemorrhoids.The aut... We have read the article by Qu et al with great interest,as it presents an inte-gration of endoscopic polidocanol foam sclerotherapy with rubber band ligation in patients with Grade II-III internal hemorrhoids.The authors conducted a prospective,multicenter,randomized study to evaluate the long-term sympto-matic and endoscopic efficacy of this combined intervention.In this discussion,we focus on the procedural steps of this combined strategy and suggest potential avenues for future research. 展开更多
关键词 Internal hemorrhoids Endoscopic therapy Polidocanol foam SCLEROTHERAPY Rubber band ligation Sclerobanding
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Endoscopic polidocanol foam sclerobanding for treatment of internal hemorrhoids:A novel outpatient procedure
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作者 An-Na Mou Yu-Ting Wang 《World Journal of Gastroenterology》 SCIE CAS 2024年第42期4583-4586,共4页
In the study,we comment on the article by Qu et al.Internal hemorrhoids are the most common anorectal disorders worldwide with bleeding,prolapse,and difficulty in defecation.Endoscopic rubber band ligation(ERBL)is a s... In the study,we comment on the article by Qu et al.Internal hemorrhoids are the most common anorectal disorders worldwide with bleeding,prolapse,and difficulty in defecation.Endoscopic rubber band ligation(ERBL)is a safe,convenient,quick,and economical outpatient procedure.The main goal of ERBL is to alleviate prolapse,but the high incidence of recurrence and post-procedural pain are of clinical concern.Polidocanol foam as a local hemostatic and anesthetic agent could reduce the rates of post-procedural pain and bleeding.Endoscopic polidocanol foam sclerobanding(EFSB)is a novel approach that could lift the mucosa for easy ligation and promote increased scarring in the submucosal tissue which translates into long-term relief from prolapse recurrence and reduced 24-h postprocedural pain.The study by Qu et al is a novel multi-center prospective randomized study to compare ERBL and EFSB in patients with grades II and III internal hemorrhoids with one-year follow-up.Results showed that EFSB is a novel therapy for internal hemorrhoids,but future studies with a larger sample,multiple treatment sessions,and long-term follow-up are required to confirm these findings. 展开更多
关键词 Internal hemorrhoids Goligher classification Rubber band ligation SCLEROTHERAPY Polidocanol foam
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Van der Waals epitaxy of type-Ⅱ band alignment CsPbI_(3)/TMDC heterostructure for optoelectronic applications
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作者 Chang Lu Shunhui Zhang +6 位作者 Meili Chen Haitao Chen Mengjian Zhu Zhengwei Zhang Jun He Lin Zhang Xiaoming Yuan 《Frontiers of physics》 SCIE CSCD 2024年第5期95-107,共13页
Van der Waals epitaxy allows heterostructure formation without considering the lattice match requirement,thus is a promising method to form 2D/2D and 2D/3D heterojunction.Considering the unique optical properties of C... Van der Waals epitaxy allows heterostructure formation without considering the lattice match requirement,thus is a promising method to form 2D/2D and 2D/3D heterojunction.Considering the unique optical properties of CsPbI_(3) and transition metal dichalcogenides(TMDCs),their heterostructure present potential applications in both photonics and optoelectronics fields.Here,we demonstrate selective growth of cubic phase CsPbI_(3) nanofilm with thickness as thin as 4.0 nm and Zigzag/armchair orientated nanowires(NWs)on monolayer WSe_(2).Furthermore,we show growth of CsPbI_(3) on both transferred WSe_(2) on copper grid and WSe_(2) based optoelectrical devices,providing a platform for structure analysis and device performance modification.Transmission electron microscopy(TEM)results reveal the epitaxial nature of cubic CsPbI_(3) phase.The revealed growth fundamental of CsPbI_(3) is universal valid for other twodimensional substrates,offering a great advantage to fabricate CsPbI_(3) based van der Waals heterostructures(vdWHs).X-ray photoelectron spectroscopy(XPS)and optical characterization confirm the type-II band alignment,resulting in a fast charger transfer process and the occurrence of a broad emission peak with lower energy.The formation of WSe_(2)/CsPbI_(3) heterostructure largely enhance the photocurrent from 2.38 nA to 38.59 nA.These findings are vital for bottom-up epitaxy of inorganic semiconductor on atomic thin 2D substrates for optoelectronic applications. 展开更多
关键词 van der Waals epitaxy band alignment growth fundamental charge transfer PHOTODETECTOR
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