In recent years,there has been a surge of interest in higher-order topological phases(HOTPs)across various disciplines within the field of physics.These unique phases are characterized by their ability to harbor topol...In recent years,there has been a surge of interest in higher-order topological phases(HOTPs)across various disciplines within the field of physics.These unique phases are characterized by their ability to harbor topological protected boundary states at lower-dimensional boundaries,a distinguishing feature that sets them apart from conventional topological phases and is attributed to the higher-order bulk-boundary correspondence.Two-dimensional(2D)twisted systems offer an optimal platform for investigating HOTPs,owing to their strong controllability and experimental feasibility.Here,we provide a comprehensive overview of the latest research advancements on HOTPs in 2D twisted multilayer systems.We will mainly review the HOTPs in electronic,magnonic,acoustic,photonic and mechanical twisted systems,and finally provide a perspective of this topic.展开更多
Helsmoortel-Van der Aa综合征(HVDAS)是一种罕见的神经发育障碍性疾病,主要由活性依赖性神经保护蛋白(ADNP)基因突变引起,是最常见的孤独症谱系障碍(ASD)单基因病因之一。本文分析2024年就诊于海口市妇幼保健院的1例患儿,男,3岁10个月...Helsmoortel-Van der Aa综合征(HVDAS)是一种罕见的神经发育障碍性疾病,主要由活性依赖性神经保护蛋白(ADNP)基因突变引起,是最常见的孤独症谱系障碍(ASD)单基因病因之一。本文分析2024年就诊于海口市妇幼保健院的1例患儿,男,3岁10个月,因“运动、语言发育迟缓2年余,社交障碍1年余”入院,检查发现患儿存在孤独症谱系障碍、全面发育迟缓、特殊面容、矮小、脑积水等临床表现,基因检测发现患儿携带ADNP基因杂合突变{NM_001282531.3(ADNP):c.2189(exon6)delG[p.(Arg730Glnfs3)]},其父母及妹妹均未携带该突变。总结临床资料并结合文献复习,ADNP基因在染色质重塑和神经发育障碍中发挥重要作用,ADNP基因突变可累及多系统。此例HVDAS具有典型临床表现,并拓宽了脑积水的表型谱,为此类基因变异的遗传咨询以及临床医师的早期识别提供了参考依据。展开更多
Helsmoortel-Van der Aa综合征(HVDAS),是一种罕见的神经发育障碍疾病,主要由功能活性依赖神经保护蛋白(ADNP)基因突变引起。该文回顾性分析了就诊于济宁医学院附属医院的1例HVDAS患儿,系1岁3个月男性幼儿,其存在运动、语言、智力发育...Helsmoortel-Van der Aa综合征(HVDAS),是一种罕见的神经发育障碍疾病,主要由功能活性依赖神经保护蛋白(ADNP)基因突变引起。该文回顾性分析了就诊于济宁医学院附属医院的1例HVDAS患儿,系1岁3个月男性幼儿,其存在运动、语言、智力发育障碍及孤独症样刻板行为,有行为问题,外貌畸形,视力异常,反复呼吸道感染等临床表现,基因检测发现患儿携带ADNP基因杂合突变c.2157C>A(p.Tyr719Ter),其父母均未携带该突变。因此,提示临床工作者要加强对该疾病的认识,做到早发现、早治疗,以积极干预,从而提高患儿的生活质量。展开更多
本文报道1例ADNP基因新发杂合变异Helsmoortel-Van der Aa综合征病例。该患儿为1岁6月男童,存在有特殊面容、智力发育低下、运动、语言发育迟缓、小手等临床表现,基因分析显示患儿ADNP基因有一个新发变异位点C.460_461insAA(p.P154Qfs*...本文报道1例ADNP基因新发杂合变异Helsmoortel-Van der Aa综合征病例。该患儿为1岁6月男童,存在有特殊面容、智力发育低下、运动、语言发育迟缓、小手等临床表现,基因分析显示患儿ADNP基因有一个新发变异位点C.460_461insAA(p.P154Qfs*7),为移码突变。Helsmoortel-Van der Aa综合征可累及多系统,基因检测有助于诊断。展开更多
The drive for efficient thermal management has intensified with the miniaturization of electronic devices.This study explores the modulation of phonon transport within graphene by introducing silicon nanoparticles inf...The drive for efficient thermal management has intensified with the miniaturization of electronic devices.This study explores the modulation of phonon transport within graphene by introducing silicon nanoparticles influenced by van der Waals forces.Our approach involves the application of non-equilibrium molecular dynamics to assess thermal conductivity while varying the interaction strength,leading to a noteworthy reduction in thermal conductivity.Furthermore,we observe a distinct attenuation in length-dependent behavior within the graphene-nanoparticles system.Our exploration combines wave packet simulations with phonon transmission calculations,aligning with a comprehensive analysis of the phonon transport regime to unveil the underlying physical mechanisms at play.Lastly,we conduct transient molecular dynamics simulations to investigate interfacial thermal conductance between the nanoparticles and the graphene,revealing an enhanced thermal boundary conductance.This research not only contributes to our understanding of phonon transport but also opens a new degree of freedom for utilizing van der Waals nanoparticle-induced resonance,offering promising avenues for the modulation of thermal properties in advanced materials and enhancing their performance in various technological applications.展开更多
为深入了解Bonhoeffer-van der Pol系统在随机激励下系统动力学行为的演化规律,研究了随机Bonhoeffer-van der Pol系统的稳态响应和随机分岔。借助路径积分方法、高斯闭合方法和蒙特卡洛模拟等,求解了噪声激励下Bonhoeffer-van der Pol...为深入了解Bonhoeffer-van der Pol系统在随机激励下系统动力学行为的演化规律,研究了随机Bonhoeffer-van der Pol系统的稳态响应和随机分岔。借助路径积分方法、高斯闭合方法和蒙特卡洛模拟等,求解了噪声激励下Bonhoeffer-van der Pol系统的平稳解,发现系统参数诱导的随机P-分岔(唯像分岔)现象。通过与蒙特卡洛模拟结果的对比,验证了所述路径积分方法的准确性。展开更多
As a typical in-memory computing hardware design, nonvolatile ternary content-addressable memories(TCAMs) enable the logic operation and data storage for high throughout in parallel big data processing. However,TCAM c...As a typical in-memory computing hardware design, nonvolatile ternary content-addressable memories(TCAMs) enable the logic operation and data storage for high throughout in parallel big data processing. However,TCAM cells based on conventional silicon-based devices suffer from structural complexity and large footprintlimitations. Here, we demonstrate an ultrafast nonvolatile TCAM cell based on the MoTe2/hBN/multilayergraphene (MLG) van der Waals heterostructure using a top-gated partial floating-gate field-effect transistor(PFGFET) architecture. Based on its ambipolar transport properties, the carrier type in the source/drain andcentral channel regions of the MoTe2 channel can be efficiently tuned by the control gate and top gate, respectively,enabling the reconfigurable operation of the device in either memory or FET mode. When working inthe memory mode, it achieves an ultrafast 60 ns programming/erase speed with a current on-off ratio of ∼105,excellent retention capability, and robust endurance. When serving as a reconfigurable transistor, unipolar p-typeand n-type FETs are obtained by adopting ultrafast 60 ns control-gate voltage pulses with different polarities.The monolithic integration of memory and logic within a single device enables the content-addressable memory(CAM) functionality. Finally, by integrating two PFGFETs in parallel, a TCAM cell with a high current ratioof ∼10^(5) between the match and mismatch states is achieved without requiring additional peripheral circuitry.These results provide a promising route for the design of high-performance TCAM devices for future in-memorycomputing applications.展开更多
The rise of smart wearable devices has driven the demand for flexible,high-performance optoelectronic devices with low power and easy high-density integration.Emerging Two-dimensional(2D)materials offer promising solu...The rise of smart wearable devices has driven the demand for flexible,high-performance optoelectronic devices with low power and easy high-density integration.Emerging Two-dimensional(2D)materials offer promising solutions.However,the use of 3D metal in traditional 2D devices often leads to Fermi-level pinning,compromising device performance.2D metallic materials,such as graphene and 2H-phase NbSe_(2),present a new avenue for addressing this issue and constructing high-performance,low-power photodetectors.In this work,we designed an all-2D asymmetric contacts photodetector using Gr and NbSe_(2)as electrodes for the 2D semiconductor WSe_(2).The asymmetric Schottky barriers and built-in electric fields facilitated by this architecture resulted in outstanding photovoltaic characteristics and self-powered photodetection.Under zero bias,the device exhibited a responsivity of 287 mA/W,a specific detectivity of 5.3×10^(11)Jones,and an external quantum efficiency of 88%.It also demonstrated an ultra-high light on/offratio(1.8×10^(5)),ultra-fast photoresponse speeds(80/72μs),broad-spectrum responsiveness(405980 nm),and exceptional cycling stability.The applications of the Gr/WSe_(2)/NbSe_(2)heterojunction in imaging and infrared optical communication have been explored,underscoring its significant potential.This work offers an idea to construct all-2D ultrathin optoelectronic devices.展开更多
The magnons(the quanta of collective spin-wave excitations)in two-dimensional van der Waals(vd W)magnets exhibit some intriguing characteristics,such as spin Nernst effect,topological magnons,Weyl magnons,moiréma...The magnons(the quanta of collective spin-wave excitations)in two-dimensional van der Waals(vd W)magnets exhibit some intriguing characteristics,such as spin Nernst effect,topological magnons,Weyl magnons,moirémagnons,magnon valley Hall effect,etc.,and can be regulated through approaches such as stacking,electric doping,pressure,strain and twisting,opening unprecedented avenues to explore fundamental magnetic physics and spin-based technologies.Over the past few years,intense research efforts have been invested in unraveling magnon properties in vd W materials.This review comprehensively summarizes recent advancements in understanding magnons in vd W magnetic systems,spanning fundamental theories and experimental frontiers.It also introduces the experimental techniques widely used in this field,including inelastic neutron scattering,Raman/Brillouin spectroscopy,time-resolved spectroscopy and inelastic magnetotunneling spectroscopy,and discusses the coupling between magnons and other excitations,such as phonons and excitons.展开更多
Two-dimensional van der Waals ferromagnet Fe_(3)GeTe_(2)(FGT)holds a great potential for applications in spintronic devices due to its high Curie temperature,easy tunability,and excellent structural stability in air.T...Two-dimensional van der Waals ferromagnet Fe_(3)GeTe_(2)(FGT)holds a great potential for applications in spintronic devices due to its high Curie temperature,easy tunability,and excellent structural stability in air.Theoretical studies have shown that pressure,as an external parameter,significantly affects its ferromagnetic properties.In this study,we have performed comprehensive high-pressure neutron powder diffraction(NPD)experiments on FGT up to 5 GPa to investigate the evolution of its structural and magnetic properties with hydrostatic pressure.The NPD data clearly reveal the robustness of the ferromagnetism in FGT,despite of an apparent suppression by hydrostatic pressure.As the pressure increases from 0 to 5 GPa,the Curie temperature is found to decrease monotonically from 225(5)K to 175(5)K,together with a dramatically suppressed ordered moment of Fe,which is well supported by the first-principles calculations.Although no pressure-driven structural phase transition is observed up to 5 GPa,quantitative analysis on the changes of bond lengths and bond angles indicates a significant modification of the exchange interactions,which accounts for the pressure-induced suppression of the ferromagnetism in FGT.展开更多
Ultrasound is a powerful tool in materials processing,yet its application in constructing van der Waals(vdW)heterostructures remains under-explored.In this study,MoS_(2)and graphene—two widely studied 2D materials—w...Ultrasound is a powerful tool in materials processing,yet its application in constructing van der Waals(vdW)heterostructures remains under-explored.In this study,MoS_(2)and graphene—two widely studied 2D materials—were successfully assembled into vdW heterostructures via a convenient ultrasound-driven self-assembly approach.The morphology of the heterostructures was characterized by scanning electron microscopy(SEM),while their structural and compositional features were confirmed through x-ray diffraction(XRD),Raman spectroscopy,and x-ray photoelectron spectroscopy(XPS).Red-shifted Raman peaks and decreased binding energies in XPS spectra provided strong evidence of successful heterostructure formation.A three-stage assembly mechanism—comprising dispersion,assembly,and adjustment—is proposed,with acoustic cavitation playing a key role in driving the process.This study not only demonstrates the feasibility of synthesizing 2D heterostructures via an ultrasonic route but also lays a foundation for future scalable,energy-efficient fabrication strategies.展开更多
Spin waves in van der Waals magnets hold promise for magnonic devices and circuits down to the two-dimensional limit.However,their short decay lengths pose challenges for practical applications.Here,we report on a mat...Spin waves in van der Waals magnets hold promise for magnonic devices and circuits down to the two-dimensional limit.However,their short decay lengths pose challenges for practical applications.Here,we report on a material platform consisting of a van der Waals magnet,Fe_(5)GeTe_(2)(FGT),and a ferrimagnetic insulator of yttrium iron garnet,Y_(3)Fe_(5)O_(12)(YIG),which supports the low-loss propagation of spin waves.Using broadband spin-wave spectroscopy,we observed an increase in spin-wave group velocity with decreasing temperature,which peaks at 30 K in the YIG and FGT/YIG films.This effect is ascribed to a change in the saturation magnetization of YIG and FGT/YIG at low temperature,resulting in a change in the spin-wave dispersion relations.Using micromagnetic simulations,we further investigated spin-wave propagation in an FGT/YIG bilayer and revealed a longer spin-wave decay length in the bilayer than in a single FGT layer,which is due to the lower effective damping in the bilayer.Moreover,asymmetric spin-wave dispersion,induced by a chiral dipolar interaction between the YIG and FGT layers,enables nonreciprocal control of spin-wave propagation.展开更多
Self-intercalated van der Waals magnets,characterized by self-intercalating native atoms into van der Waals layered structures with intrinsic magnetism,exhibit a variety of novel physical properties.Here,using first-p...Self-intercalated van der Waals magnets,characterized by self-intercalating native atoms into van der Waals layered structures with intrinsic magnetism,exhibit a variety of novel physical properties.Here,using first-principles calculations and Monte Carlo simulations,we report a self-intercalated van der Waals ferromagnet,Cr_(3)Ge_(2)Te_(6),which has a high Curie temperature of 492 K.We find that Cr_(3)Ge_(2)Te_(6)is nearly half-metallic with a spin polarization reaching up to 90.9%.Due to the ferromagnetism and strong spin-orbit coupling effect in Cr_(3)Ge_(2)Te_(6),a large anomalous Hall conductivity of 138Ω^(-1)·cm^(-1)and 305Ω^(-1)·cm^(-1)can be realized when its magnetization is along its magnetic easy axis and hard axis,respectively.By doping electrons(holes)into Cr_(3)Ge_(2)Te_(6),these anomalous Hall conductivities can be increased up to 318Ω^(-1)·cm^(-1)(648Ω^(-1)·cm^(-1)).Interestingly,a five-layer Cr_(3)Ge_(2)Te_(6)thin film retains room-temperature ferromagnetism with a higher spin polarization and larger anomalous Hall conductivity.Our study demonstrates that Cr_(3)Ge_(2)Te_(6)is a novel room-temperature self-intercalated ferromagnet with high-spin polarization and large anomalous Hall conductivity,offering great opportunities for designing nano-scale electronic devices.展开更多
“Der Wille zur Macht”在尼采哲学中处于核心地位,它是对存在者整体的本质性规定,同时也是理解西方哲学的重要节点和绕不开的研究任务。在批判性继承叔本华“意志”概念的基础上,尼采发展出自己独特的“Der Wille zur Macht”理念,从...“Der Wille zur Macht”在尼采哲学中处于核心地位,它是对存在者整体的本质性规定,同时也是理解西方哲学的重要节点和绕不开的研究任务。在批判性继承叔本华“意志”概念的基础上,尼采发展出自己独特的“Der Wille zur Macht”理念,从词源解析该词可直译为“向力量/权力的意志”。该词的各种历史中文译名诸如从“权力意志”到“强力意志”等的局限性胜于其优点。新的中文译名“趋力意志”为“Der Wille zur Macht”的中文翻译提供了新思路,更为贴近该词的哲学内涵,强调“意志”所具有的趋向“力量/权力”的本质,以及朝向更高和更丰富的、积极的和动态的生命特性;同时也符合翻译的简洁原则;为理解尼采哲学提供了更为清晰的视角。展开更多
Suppose that c,d,α,β,are real numbers satisfying 1<d<c<14=13,1<α<β<6^(1−d=c).In this paper,we prove that there exist numbers N_(1)^((0))and N_(2)^((0)),depending on c,d,α,β,such that for all re...Suppose that c,d,α,β,are real numbers satisfying 1<d<c<14=13,1<α<β<6^(1−d=c).In this paper,we prove that there exist numbers N_(1)^((0))and N_(2)^((0)),depending on c,d,α,β,such that for all real numbers N1_(1)and N_(2)satisfying N_(1)>N_(1)^((0)),N_(2)>N_(2)^((0))andα≤N_(2)/N_(1)^(d=c)≤β,the system of two Diophantine inequalities|p_^(1)+…+p_(6)^(c)-N_(1)|<N_(1)^(−(1=c)(14=13−c))logN_(1),|p_(1)^(d)+…+p_(6)^(d)|N_(2)^(−(1=d)(14=13−d))logN_(2)has solutions in prime variables p_(1)…,p6.展开更多
Recent advances in van der Waals(vdW) ferroelectrics have sparked the development of related heterostructures with non-volatile and field-tunable functionalities. In vdW ferroelectric heterojunctions, the interfacial ...Recent advances in van der Waals(vdW) ferroelectrics have sparked the development of related heterostructures with non-volatile and field-tunable functionalities. In vdW ferroelectric heterojunctions, the interfacial electrical characteristics play a crucial role in determining their performance and functionality. In this study,we explore the interfacial polarization coupling in two-dimensional(2D) ferroelectric heterojunctions by fabricating a graphene/h-BN/CuInP_(2)S_(6)/α-In_(2)Se_(3)/Au ferroelectric field-effect transistor. By varying the gate electric field, the CuInP_(2)S_(6)/α-In_(2)Se_(3) heterojunction displays distinct interfacial polarization coupling states, resulting in significantly different electrical transport behaviors. Under strong gate electric fields, the migration of Cu ions further enhances the interfacial polarization effect, enabling continuous tuning of both the polarization state and carrier concentration in α-In_(2)Se_(3). Our findings offer valuable insights for the development of novel multifunctional devices based on 2D ferroelectric materials.展开更多
Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanopart...Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering.Here we report the direct epitaxial growth of well-aligned,highly atomically ordered Pt3 Fe and PtFe nanoparticles(<5 nm)on single-walled carbon nanotube(SWCNT)bundles films.The long-range periodically symmetric van der Waals(vdW)interac-tions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles.The ordered Pt_(3)Fe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C.Moreover,the formation of an interlocked inter-face and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.展开更多
The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typicall...The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typically achieved via ionic gating)to shift the vHS to the Fermi level provides a general mechanism for engineering such magnetism,its volatile nature often leads to the collapse of induced states upon gate field removal.Here,a novel scheme is presented for non-volatile magnetic control by utilizing ferroelectric heterostructures to achieve reversible magnetism switching.Using two-dimensional VSiN_(3),a nonmagnetic material with Mexican-hat electronic band dispersions hosting vHSs,as a prototype,it is preliminarily demonstrated that both electron and hole doping can robustly induce magnetism.Further,by interfacing VSiN_(3)with ferroelectric Sc_(2)CO_(2),reversible switching of its magnetic state via polarization-driven heterointerfacial charge transfer is achieved.This mechanism enables a dynamic transition between insulating and half-metallic phases in VSiN_(3),establishing a pathway to design multiferroic tunnel junctions with giant tunneling electroresistance or magnetoresistance.This work bridges non-volatile ferroelectric control with vHS-enhanced magnetism,opening opportunities for energy-efficient and high-performance spintronic devices and non-volatile memory devices.展开更多
The exploration of heterostructures composed of two-dimensional(2D)transition metal dichalcogenide(TMDc)materials has garnered significant research attention due to the distinctive properties of each individual compon...The exploration of heterostructures composed of two-dimensional(2D)transition metal dichalcogenide(TMDc)materials has garnered significant research attention due to the distinctive properties of each individual component and their phase-dependent unique properties.Using the plasma-enhanced chemical vapor deposition(PECVD)method,we analyze the fabrication of heterostructures consisting of two phases of molybdenum disulfide(MoS_(2))in four different cases.The initial hydrogen evolution reaction(HER)polarization curve indicates that the activity of the heterostructure MoS_(2)is consistent with that of the underlying MoS_(2),rather than the surface activity of the upper MoS_(2).This behavior can be attributed to the presence of Schottky barriers,which include contact resistance,which significantly hampers the efficient charge transfer at junctions between the two different phases of MoS_(2)layers and is mediated by van der Waals bonds.Remarkably,the energy barrier at the junction dissipates upon reaching a certain electrochemical potential,indicating surface activation from the top phase of MoS_(2)in the heterostructure.Notably,the 1T/2H MoS_(2)heterostructure demonstrates enhanced electrochemical stability compared to its metastable 1T-MoS_(2).This fundamental understanding paves the way for the creation of phase-controllable heterostructures through an experimentally viable PECVD,offering significant promise for a wide range of applications.展开更多
The Chebyshev polynomial approximation is applied to investigate the stochastic period-doubling bifurcation and chaos problems of a stochastic Duffing-van der Pol system with bounded random parameter of exponential pr...The Chebyshev polynomial approximation is applied to investigate the stochastic period-doubling bifurcation and chaos problems of a stochastic Duffing-van der Pol system with bounded random parameter of exponential probability density function subjected to a harmonic excitation. Firstly the stochastic system is reduced into its equivalent deterministic one, and then the responses of stochastic system can be obtained by numerical methods. Nonlinear dynamical behaviour related to stochastic period-doubling bifurcation and chaos in the stochastic system is explored. Numerical simulations show that similar to its counterpart in deterministic nonlinear system of stochastic period-doubling bifurcation and chaos may occur in the stochastic Duffing-van der Pol system even for weak intensity of random parameter. Simply increasing the intensity of the random parameter may result in the period-doubling bifurcation which is absent from the deterministic system.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12304539,12074108,12474151,12347101)the Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQ-MSX0568)Beijing National Laboratory for Condensed Matter Physics(Grant No.2024BNLCMPKF025)。
文摘In recent years,there has been a surge of interest in higher-order topological phases(HOTPs)across various disciplines within the field of physics.These unique phases are characterized by their ability to harbor topological protected boundary states at lower-dimensional boundaries,a distinguishing feature that sets them apart from conventional topological phases and is attributed to the higher-order bulk-boundary correspondence.Two-dimensional(2D)twisted systems offer an optimal platform for investigating HOTPs,owing to their strong controllability and experimental feasibility.Here,we provide a comprehensive overview of the latest research advancements on HOTPs in 2D twisted multilayer systems.We will mainly review the HOTPs in electronic,magnonic,acoustic,photonic and mechanical twisted systems,and finally provide a perspective of this topic.
文摘Helsmoortel-Van der Aa综合征(HVDAS)是一种罕见的神经发育障碍性疾病,主要由活性依赖性神经保护蛋白(ADNP)基因突变引起,是最常见的孤独症谱系障碍(ASD)单基因病因之一。本文分析2024年就诊于海口市妇幼保健院的1例患儿,男,3岁10个月,因“运动、语言发育迟缓2年余,社交障碍1年余”入院,检查发现患儿存在孤独症谱系障碍、全面发育迟缓、特殊面容、矮小、脑积水等临床表现,基因检测发现患儿携带ADNP基因杂合突变{NM_001282531.3(ADNP):c.2189(exon6)delG[p.(Arg730Glnfs3)]},其父母及妹妹均未携带该突变。总结临床资料并结合文献复习,ADNP基因在染色质重塑和神经发育障碍中发挥重要作用,ADNP基因突变可累及多系统。此例HVDAS具有典型临床表现,并拓宽了脑积水的表型谱,为此类基因变异的遗传咨询以及临床医师的早期识别提供了参考依据。
文摘Helsmoortel-Van der Aa综合征(HVDAS),是一种罕见的神经发育障碍疾病,主要由功能活性依赖神经保护蛋白(ADNP)基因突变引起。该文回顾性分析了就诊于济宁医学院附属医院的1例HVDAS患儿,系1岁3个月男性幼儿,其存在运动、语言、智力发育障碍及孤独症样刻板行为,有行为问题,外貌畸形,视力异常,反复呼吸道感染等临床表现,基因检测发现患儿携带ADNP基因杂合突变c.2157C>A(p.Tyr719Ter),其父母均未携带该突变。因此,提示临床工作者要加强对该疾病的认识,做到早发现、早治疗,以积极干预,从而提高患儿的生活质量。
文摘本文报道1例ADNP基因新发杂合变异Helsmoortel-Van der Aa综合征病例。该患儿为1岁6月男童,存在有特殊面容、智力发育低下、运动、语言发育迟缓、小手等临床表现,基因分析显示患儿ADNP基因有一个新发变异位点C.460_461insAA(p.P154Qfs*7),为移码突变。Helsmoortel-Van der Aa综合征可累及多系统,基因检测有助于诊断。
基金funded in parts by the National Natural Science Foundation of China (Grant No.12105242)Yunnan Fundamental Research Project (Grant Nos.202201AT070161 and 202301AW070006)support from the Graduate Scientific Research and Innovation Fund of Yunnan University (Grant No.KC-22221060)。
文摘The drive for efficient thermal management has intensified with the miniaturization of electronic devices.This study explores the modulation of phonon transport within graphene by introducing silicon nanoparticles influenced by van der Waals forces.Our approach involves the application of non-equilibrium molecular dynamics to assess thermal conductivity while varying the interaction strength,leading to a noteworthy reduction in thermal conductivity.Furthermore,we observe a distinct attenuation in length-dependent behavior within the graphene-nanoparticles system.Our exploration combines wave packet simulations with phonon transmission calculations,aligning with a comprehensive analysis of the phonon transport regime to unveil the underlying physical mechanisms at play.Lastly,we conduct transient molecular dynamics simulations to investigate interfacial thermal conductance between the nanoparticles and the graphene,revealing an enhanced thermal boundary conductance.This research not only contributes to our understanding of phonon transport but also opens a new degree of freedom for utilizing van der Waals nanoparticle-induced resonance,offering promising avenues for the modulation of thermal properties in advanced materials and enhancing their performance in various technological applications.
文摘为深入了解Bonhoeffer-van der Pol系统在随机激励下系统动力学行为的演化规律,研究了随机Bonhoeffer-van der Pol系统的稳态响应和随机分岔。借助路径积分方法、高斯闭合方法和蒙特卡洛模拟等,求解了噪声激励下Bonhoeffer-van der Pol系统的平稳解,发现系统参数诱导的随机P-分岔(唯像分岔)现象。通过与蒙特卡洛模拟结果的对比,验证了所述路径积分方法的准确性。
基金supported by the National Key Research&Development Projects of China(Grant No.2022YFA1204100)National Natural Science Foundation of China(Grant No.62488201)+1 种基金CAS Project for Young Scientists in Basic Research(YSBR-003)the Innovation Program of Quantum Science and Technology(2021ZD0302700)。
文摘As a typical in-memory computing hardware design, nonvolatile ternary content-addressable memories(TCAMs) enable the logic operation and data storage for high throughout in parallel big data processing. However,TCAM cells based on conventional silicon-based devices suffer from structural complexity and large footprintlimitations. Here, we demonstrate an ultrafast nonvolatile TCAM cell based on the MoTe2/hBN/multilayergraphene (MLG) van der Waals heterostructure using a top-gated partial floating-gate field-effect transistor(PFGFET) architecture. Based on its ambipolar transport properties, the carrier type in the source/drain andcentral channel regions of the MoTe2 channel can be efficiently tuned by the control gate and top gate, respectively,enabling the reconfigurable operation of the device in either memory or FET mode. When working inthe memory mode, it achieves an ultrafast 60 ns programming/erase speed with a current on-off ratio of ∼105,excellent retention capability, and robust endurance. When serving as a reconfigurable transistor, unipolar p-typeand n-type FETs are obtained by adopting ultrafast 60 ns control-gate voltage pulses with different polarities.The monolithic integration of memory and logic within a single device enables the content-addressable memory(CAM) functionality. Finally, by integrating two PFGFETs in parallel, a TCAM cell with a high current ratioof ∼10^(5) between the match and mismatch states is achieved without requiring additional peripheral circuitry.These results provide a promising route for the design of high-performance TCAM devices for future in-memorycomputing applications.
基金Liming Gao acknowledges funding from the National Natural Science Foundation of China(No.61727805).
文摘The rise of smart wearable devices has driven the demand for flexible,high-performance optoelectronic devices with low power and easy high-density integration.Emerging Two-dimensional(2D)materials offer promising solutions.However,the use of 3D metal in traditional 2D devices often leads to Fermi-level pinning,compromising device performance.2D metallic materials,such as graphene and 2H-phase NbSe_(2),present a new avenue for addressing this issue and constructing high-performance,low-power photodetectors.In this work,we designed an all-2D asymmetric contacts photodetector using Gr and NbSe_(2)as electrodes for the 2D semiconductor WSe_(2).The asymmetric Schottky barriers and built-in electric fields facilitated by this architecture resulted in outstanding photovoltaic characteristics and self-powered photodetection.Under zero bias,the device exhibited a responsivity of 287 mA/W,a specific detectivity of 5.3×10^(11)Jones,and an external quantum efficiency of 88%.It also demonstrated an ultra-high light on/offratio(1.8×10^(5)),ultra-fast photoresponse speeds(80/72μs),broad-spectrum responsiveness(405980 nm),and exceptional cycling stability.The applications of the Gr/WSe_(2)/NbSe_(2)heterojunction in imaging and infrared optical communication have been explored,underscoring its significant potential.This work offers an idea to construct all-2D ultrathin optoelectronic devices.
基金the Chinese Academy of Sciences—the Scientific and the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-120)the National Science Foundation of China(Grant No.NSFC12525405)。
文摘The magnons(the quanta of collective spin-wave excitations)in two-dimensional van der Waals(vd W)magnets exhibit some intriguing characteristics,such as spin Nernst effect,topological magnons,Weyl magnons,moirémagnons,magnon valley Hall effect,etc.,and can be regulated through approaches such as stacking,electric doping,pressure,strain and twisting,opening unprecedented avenues to explore fundamental magnetic physics and spin-based technologies.Over the past few years,intense research efforts have been invested in unraveling magnon properties in vd W materials.This review comprehensively summarizes recent advancements in understanding magnons in vd W magnetic systems,spanning fundamental theories and experimental frontiers.It also introduces the experimental techniques widely used in this field,including inelastic neutron scattering,Raman/Brillouin spectroscopy,time-resolved spectroscopy and inelastic magnetotunneling spectroscopy,and discusses the coupling between magnons and other excitations,such as phonons and excitons.
基金Project supported by the National Natural Science Foundation of China(Grant No.12074023)the Large Scientific Facility Open Subject of Songshan Lake(Grant No.KFKT2022B05)+1 种基金the Fundamental Research Funds for the Central Universities in ChinaNeutron diffraction experiments at the Materials and Life Science Experimental Facility of the J-PARC were performed through the user program(Proposal No.2023A0185).
文摘Two-dimensional van der Waals ferromagnet Fe_(3)GeTe_(2)(FGT)holds a great potential for applications in spintronic devices due to its high Curie temperature,easy tunability,and excellent structural stability in air.Theoretical studies have shown that pressure,as an external parameter,significantly affects its ferromagnetic properties.In this study,we have performed comprehensive high-pressure neutron powder diffraction(NPD)experiments on FGT up to 5 GPa to investigate the evolution of its structural and magnetic properties with hydrostatic pressure.The NPD data clearly reveal the robustness of the ferromagnetism in FGT,despite of an apparent suppression by hydrostatic pressure.As the pressure increases from 0 to 5 GPa,the Curie temperature is found to decrease monotonically from 225(5)K to 175(5)K,together with a dramatically suppressed ordered moment of Fe,which is well supported by the first-principles calculations.Although no pressure-driven structural phase transition is observed up to 5 GPa,quantitative analysis on the changes of bond lengths and bond angles indicates a significant modification of the exchange interactions,which accounts for the pressure-induced suppression of the ferromagnetism in FGT.
基金supported by the China Inner Mongolia Autonomous Region Directly-Undergraduate Universities Basic Research Business Fund Project:‘Environmental Protection Equipment R&D’Shared Technology and Skills Innovation Platform Construction(Grant No.NJDYWF2301).
文摘Ultrasound is a powerful tool in materials processing,yet its application in constructing van der Waals(vdW)heterostructures remains under-explored.In this study,MoS_(2)and graphene—two widely studied 2D materials—were successfully assembled into vdW heterostructures via a convenient ultrasound-driven self-assembly approach.The morphology of the heterostructures was characterized by scanning electron microscopy(SEM),while their structural and compositional features were confirmed through x-ray diffraction(XRD),Raman spectroscopy,and x-ray photoelectron spectroscopy(XPS).Red-shifted Raman peaks and decreased binding energies in XPS spectra provided strong evidence of successful heterostructure formation.A three-stage assembly mechanism—comprising dispersion,assembly,and adjustment—is proposed,with acoustic cavitation playing a key role in driving the process.This study not only demonstrates the feasibility of synthesizing 2D heterostructures via an ultrasonic route but also lays a foundation for future scalable,energy-efficient fabrication strategies.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1402400)the National Natural Science Foundation of China(Grant No.12374119)the support of the Center for Nanoscience and Nanotechnology and the Supercomputing Center at Wuhan University in China。
文摘Spin waves in van der Waals magnets hold promise for magnonic devices and circuits down to the two-dimensional limit.However,their short decay lengths pose challenges for practical applications.Here,we report on a material platform consisting of a van der Waals magnet,Fe_(5)GeTe_(2)(FGT),and a ferrimagnetic insulator of yttrium iron garnet,Y_(3)Fe_(5)O_(12)(YIG),which supports the low-loss propagation of spin waves.Using broadband spin-wave spectroscopy,we observed an increase in spin-wave group velocity with decreasing temperature,which peaks at 30 K in the YIG and FGT/YIG films.This effect is ascribed to a change in the saturation magnetization of YIG and FGT/YIG at low temperature,resulting in a change in the spin-wave dispersion relations.Using micromagnetic simulations,we further investigated spin-wave propagation in an FGT/YIG bilayer and revealed a longer spin-wave decay length in the bilayer than in a single FGT layer,which is due to the lower effective damping in the bilayer.Moreover,asymmetric spin-wave dispersion,induced by a chiral dipolar interaction between the YIG and FGT layers,enables nonreciprocal control of spin-wave propagation.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1403301)the National Natural Science Foundation of China(Grant Nos.12474247 and 92165204)+1 种基金the Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)the support from the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(Grant No.24qnpy108)。
文摘Self-intercalated van der Waals magnets,characterized by self-intercalating native atoms into van der Waals layered structures with intrinsic magnetism,exhibit a variety of novel physical properties.Here,using first-principles calculations and Monte Carlo simulations,we report a self-intercalated van der Waals ferromagnet,Cr_(3)Ge_(2)Te_(6),which has a high Curie temperature of 492 K.We find that Cr_(3)Ge_(2)Te_(6)is nearly half-metallic with a spin polarization reaching up to 90.9%.Due to the ferromagnetism and strong spin-orbit coupling effect in Cr_(3)Ge_(2)Te_(6),a large anomalous Hall conductivity of 138Ω^(-1)·cm^(-1)and 305Ω^(-1)·cm^(-1)can be realized when its magnetization is along its magnetic easy axis and hard axis,respectively.By doping electrons(holes)into Cr_(3)Ge_(2)Te_(6),these anomalous Hall conductivities can be increased up to 318Ω^(-1)·cm^(-1)(648Ω^(-1)·cm^(-1)).Interestingly,a five-layer Cr_(3)Ge_(2)Te_(6)thin film retains room-temperature ferromagnetism with a higher spin polarization and larger anomalous Hall conductivity.Our study demonstrates that Cr_(3)Ge_(2)Te_(6)is a novel room-temperature self-intercalated ferromagnet with high-spin polarization and large anomalous Hall conductivity,offering great opportunities for designing nano-scale electronic devices.
文摘“Der Wille zur Macht”在尼采哲学中处于核心地位,它是对存在者整体的本质性规定,同时也是理解西方哲学的重要节点和绕不开的研究任务。在批判性继承叔本华“意志”概念的基础上,尼采发展出自己独特的“Der Wille zur Macht”理念,从词源解析该词可直译为“向力量/权力的意志”。该词的各种历史中文译名诸如从“权力意志”到“强力意志”等的局限性胜于其优点。新的中文译名“趋力意志”为“Der Wille zur Macht”的中文翻译提供了新思路,更为贴近该词的哲学内涵,强调“意志”所具有的趋向“力量/权力”的本质,以及朝向更高和更丰富的、积极的和动态的生命特性;同时也符合翻译的简洁原则;为理解尼采哲学提供了更为清晰的视角。
文摘Suppose that c,d,α,β,are real numbers satisfying 1<d<c<14=13,1<α<β<6^(1−d=c).In this paper,we prove that there exist numbers N_(1)^((0))and N_(2)^((0)),depending on c,d,α,β,such that for all real numbers N1_(1)and N_(2)satisfying N_(1)>N_(1)^((0)),N_(2)>N_(2)^((0))andα≤N_(2)/N_(1)^(d=c)≤β,the system of two Diophantine inequalities|p_^(1)+…+p_(6)^(c)-N_(1)|<N_(1)^(−(1=c)(14=13−c))logN_(1),|p_(1)^(d)+…+p_(6)^(d)|N_(2)^(−(1=d)(14=13−d))logN_(2)has solutions in prime variables p_(1)…,p6.
基金supported by the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-049)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)the Fundamental Research Funds for the Central Universities(Grant No.WK3510000013)。
文摘Recent advances in van der Waals(vdW) ferroelectrics have sparked the development of related heterostructures with non-volatile and field-tunable functionalities. In vdW ferroelectric heterojunctions, the interfacial electrical characteristics play a crucial role in determining their performance and functionality. In this study,we explore the interfacial polarization coupling in two-dimensional(2D) ferroelectric heterojunctions by fabricating a graphene/h-BN/CuInP_(2)S_(6)/α-In_(2)Se_(3)/Au ferroelectric field-effect transistor. By varying the gate electric field, the CuInP_(2)S_(6)/α-In_(2)Se_(3) heterojunction displays distinct interfacial polarization coupling states, resulting in significantly different electrical transport behaviors. Under strong gate electric fields, the migration of Cu ions further enhances the interfacial polarization effect, enabling continuous tuning of both the polarization state and carrier concentration in α-In_(2)Se_(3). Our findings offer valuable insights for the development of novel multifunctional devices based on 2D ferroelectric materials.
基金supported by the National Natural Science Foundation of China(grant Nos.52073290 and 51927803)the Liaoning Province Science and Technology Plan Project(No.2022-MS-011)the Shenyang science and technology plan project(23-407-3-23).
文摘Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering.Here we report the direct epitaxial growth of well-aligned,highly atomically ordered Pt3 Fe and PtFe nanoparticles(<5 nm)on single-walled carbon nanotube(SWCNT)bundles films.The long-range periodically symmetric van der Waals(vdW)interac-tions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles.The ordered Pt_(3)Fe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C.Moreover,the formation of an interlocked inter-face and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.
基金supported by the National Natural Science Foundation of China(Grant Nos.62174016,12474047,12204202,and 11974355)the Basic Research Program of Jiangsu(Grant No.BK20220679)+1 种基金the Fund for Shanxi“1331Project”the Research Project Supported by Shanxi Scholarship Council of China.
文摘The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typically achieved via ionic gating)to shift the vHS to the Fermi level provides a general mechanism for engineering such magnetism,its volatile nature often leads to the collapse of induced states upon gate field removal.Here,a novel scheme is presented for non-volatile magnetic control by utilizing ferroelectric heterostructures to achieve reversible magnetism switching.Using two-dimensional VSiN_(3),a nonmagnetic material with Mexican-hat electronic band dispersions hosting vHSs,as a prototype,it is preliminarily demonstrated that both electron and hole doping can robustly induce magnetism.Further,by interfacing VSiN_(3)with ferroelectric Sc_(2)CO_(2),reversible switching of its magnetic state via polarization-driven heterointerfacial charge transfer is achieved.This mechanism enables a dynamic transition between insulating and half-metallic phases in VSiN_(3),establishing a pathway to design multiferroic tunnel junctions with giant tunneling electroresistance or magnetoresistance.This work bridges non-volatile ferroelectric control with vHS-enhanced magnetism,opening opportunities for energy-efficient and high-performance spintronic devices and non-volatile memory devices.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(2022R1A3B1078163 and 2022R1A4A1031182)supported by the KIMM institutional program(NK248E)and NST/KIMM+3 种基金supported by the Technology Innovation Program(or Industrial Strategic Technology Development Program)(20024772),(RS-2023-00264860)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)(1415187508)supported by the US Department of Energy,Office of Science,Office of Basic Energy Sciences,under grant no.DE-FG02-87ER13808by Northwestern University.
文摘The exploration of heterostructures composed of two-dimensional(2D)transition metal dichalcogenide(TMDc)materials has garnered significant research attention due to the distinctive properties of each individual component and their phase-dependent unique properties.Using the plasma-enhanced chemical vapor deposition(PECVD)method,we analyze the fabrication of heterostructures consisting of two phases of molybdenum disulfide(MoS_(2))in four different cases.The initial hydrogen evolution reaction(HER)polarization curve indicates that the activity of the heterostructure MoS_(2)is consistent with that of the underlying MoS_(2),rather than the surface activity of the upper MoS_(2).This behavior can be attributed to the presence of Schottky barriers,which include contact resistance,which significantly hampers the efficient charge transfer at junctions between the two different phases of MoS_(2)layers and is mediated by van der Waals bonds.Remarkably,the energy barrier at the junction dissipates upon reaching a certain electrochemical potential,indicating surface activation from the top phase of MoS_(2)in the heterostructure.Notably,the 1T/2H MoS_(2)heterostructure demonstrates enhanced electrochemical stability compared to its metastable 1T-MoS_(2).This fundamental understanding paves the way for the creation of phase-controllable heterostructures through an experimentally viable PECVD,offering significant promise for a wide range of applications.
基金Project supported by the National Natural Science Foundation of China （Grants Nos 10472091 and 10332030）.
文摘The Chebyshev polynomial approximation is applied to investigate the stochastic period-doubling bifurcation and chaos problems of a stochastic Duffing-van der Pol system with bounded random parameter of exponential probability density function subjected to a harmonic excitation. Firstly the stochastic system is reduced into its equivalent deterministic one, and then the responses of stochastic system can be obtained by numerical methods. Nonlinear dynamical behaviour related to stochastic period-doubling bifurcation and chaos in the stochastic system is explored. Numerical simulations show that similar to its counterpart in deterministic nonlinear system of stochastic period-doubling bifurcation and chaos may occur in the stochastic Duffing-van der Pol system even for weak intensity of random parameter. Simply increasing the intensity of the random parameter may result in the period-doubling bifurcation which is absent from the deterministic system.
