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甘肃靖远、景泰早石炭世维宪期植物群

古生物学报 2005年第2期44卷 175-202页

作者：吴秀元王军张宜 I.M.STEVANOVIC-wALLS h.w.pfefferkorn 中国科学院南京地质古生物研究所南京210008 Department of Earth and Environmental Science University of Pennsylvanian Philadelphia PA 19104-6316USA

祁连山和河西走廊区石炭纪地层发育,动植物化石丰富,是研究我国海陆交互相石炭系的重要地区。臭牛沟组系袁复礼(1925)所建,标准地点在甘肃武威西南35 km的臭牛沟,据其中的腕足类和珊瑚化石的研究,确定其时代为早石炭世维宪期(Visean)。... 详细信息

祁连山和河西走廊区石炭纪地层发育,动植物化石丰富,是研究我国海陆交互相石炭系的重要地区。臭牛沟组系袁复礼(1925)所建,标准地点在甘肃武威西南35 km的臭牛沟,据其中的腕足类和珊瑚化石的研究,确定其时代为早石炭世维宪期(Visean)。研究材料来自甘肃景泰和靖远的早石炭世臭牛沟组,这里的臭牛沟组厚约120 m左右,由泥质页岩夹煤线、粉砂岩及薄层泥灰岩、灰岩组成,为潮间潟湖相至滨海沼泽相及泥炭沼泽相沉积。含丰富的植物化石,主要分子有:Sublepidodendron sp., Lepidodendron ciyaoense sp. nov., Lep jingyuanense ***., Lepidodendron volkmannianum, Lep. gansuense sp. nov., Lep. shanyangense, Lep. cf. aolungpulukense,Lep. sp.1, Lep. sp.2, Cathaysiodendron jingyuanense, C. cf. incertum, Stigmaria ficoides, Lepidostrobophyl lum cf. lanceolatum, L. rotundifoliumsp. nov., Lepidostrobussp. 1, L. sp.2, Bothrodendron ruchengense, Ar chaeocalamites scrobiculatus, hamatophyton verticillatum, Cardiopteridium spetsbergense, C. podozamioides,Triphyllopteris collombiana , Triphyllopteris sp. ( cf. T. lescuriana Lesquereux), Rhacopteris sp.,

关键词：早石炭世植物群景泰臭牛沟组 sp. 植物化石下石炭统海陆交互相地层发育河西走廊甘肃武威珊瑚化石泥质页岩泥炭沼泽下伏地层孢子化石上覆地层牙形石带贵州罗甸腕足类孢子带石炭纪祁连山石炭系泥灰岩

豫西早二叠世掌蕨Chiropteris Kurr和髻籽羊齿Nystroemia halle有机连接标本的发现

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科学通报 2003年第18期48卷 1965-1969页

作者：王军 h.w.pfefferkorn 孙柏年刘陆军中国科学院南京地质古生物研究所 Department of Earth and Environmental Science University of Pennsylvania Philadelphia PA 19104-6316USA 兰州大学地质系

基于河南登封早二叠世肾掌蕨 Chiropteris reniformis Kawasaki和髻籽羊齿 Nystroemia pectiniformishalle有机连接的标本,确立了肾髻籽羊齿(新组合)Nystroemia reniformis(Kawasaki)***.营养叶具长柄,肾形,基部心形,全缘或具细齿;叶脉细,多次二歧分叉并结为多边形或菱形细网.生殖枝在苞片腋部着生. 苞片与营养叶同形.胚珠器官在叶性器官腋部着生或两者分别不规则地着生于生殖枝的轴上.极多的具翼双角籽倒圆锥形,呈两列状排列,珠孔朝上.该植物代表了一种新的已灭绝的裸子植物.

关键词：早二叠世掌蕨髻籽羊齿裸子植物河南化石植物

The quasi-Gramian solution of a non-commutative extension of the higher-order nonlinear Schr?dinger equation

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Communications in Theoretical Physics 2024年第3期76卷 51-61页

作者： h w A Riaz J Lin Department of Physics Zhejiang Normal UniversityJinhua 321004China

The nonlinear Schr?dinger(NLS)equation,which incorporates higher-order dispersive terms,is widely employed in the theoretical analysis of various physical *** this study,we explore the non-commutative extension of the higher-order NLS *** treat real or complex-valued functions,such as g_(1)=g_(1)(x,t)and g_(2)=g_(2)(x,t)as non-commutative,and employ the Lax pair associated with the evolution equation,as in the commutation *** derive the quasi-Gramian solution of the system by employing a binary Darboux *** soliton solutions are presented explicitly within the framework of *** visually understand the dynamics and solutions in the given example,we also provide simulations illustrating the associated ***,the solution can be used to study the stability of plane waves and to understand the generation of periodic patterns within the context of modulational instability.

关键词： integrable systems Darboux transformation solitons

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.Jeong S.w.Lee w.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： Y.h.Zhang h.Li Z.w.Yang X.Liu Q.F.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of high-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.with increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Rational design of AgGaS/ZnS/ZnS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： h.X.Lu h.Liu Z.Z.Fu Y.Y.Chen h.Q.Dai Z.hu w.L.Zhang R.Q.Guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China Yiwu Research Institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesize highly luminescent AgGaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer *** the two-step shelling process,the synthesized AgGaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum yield(PLQY)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQY reported thus far for AgGaS ***,the effect of halogen ions in Zn precursors on the shelling process was *** was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling ***,the ZnS shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AgGaS Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

A hydrodynamic modelling of wave-activated bodies for wavelet marine regions

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CLEAN ENERGY 2024年第2期8卷 35-47页

作者： Peh, J. S. Muhieldeen, Mohammed w. Shuaib, N. h. UCSI Univ Fac Engn Technol & Built Environm Mech Engn Dept Kuala Lumpur 56000 Malaysia MTC Engineer Sdn Bhd Shah Alam Selangor Malaysia

Recently, most wave energy research has targeted sea areas with high power density under extreme wave conditions for deployment. This trend often leads to higher energy costs for wave power plants. however, many marine areas with low power density, characterized by wavelet conditions and less destructive forces than extreme wave conditions, remain underexplored. Therefore, this study aimed to propose a wave-activated body model for sea regions with wavelet conditions. The wave-activated body design process encompassed site selection, parameter determination, geometry design, comparison and performance evaluation using the ANSYS (R) AQwA model. The results indicated that the proposed device achieved the desired heave motion, with an amplitude range of 1.2 to -2.5 m, validating its potential for deployment in marine regions with wavelet conditions. Notably, while the proposed design is optimized for wavelet conditions, it was found to have potential limitations in extreme wave environments. This observation emphasizes the challenge of formulating a generalized design suitable for both conditions. Consequently, it is pivotal for wave-activated body designs to be customized based on the specific ocean conditions they target, underscoring the need for specialized designs of wave energy converters that consider the unique wave characteristics of their deployment sites. A wave-activated body is designed for energy generation in ocean regions with wavelet conditions. hydrodynamic modelling is carried out for two locations with different wave characteristics to determine the optimum conditions for deployment. Graphical Abstract

关键词： wave energy converter South China sea renewable and sustainable energy wavelet ANSYS AQwA hydrodynamic wave-activated bodies ENERGY IMPACT

Charge qubits based on ultra-thin topological insulator films

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Frontiers of physics 2024年第3期19卷 71-81页

作者： Kexin Zhang hugo V.Lepage Ying Dong Crispin h.w.Barnes Research Center for Quantum Sensing Intelligent Perception Research InstituteZhejiang LabHangzhou 311121China Cavendish Laboratory Department of PhysicsUniversity of CambridgeCambridge CB30HEUnited Kingdom

we study how to use the surface states in a Bi2Se3 topological insulator ultra-thin film that are affected by finite size effects for the purpose of quantum *** demonstrate that:(i)surface states under the finite size effect can effectively form a two-level system where their energy levels lie in between the bulk energy gap and a logic qubit can be constructed,(ii)the qubit can be initialized and manipulated using electric pulses of simple forms,(iii)two-qubit entanglement is achieved through a√SwAP operation when the two qubits are in a parallel setup,and(iv)alternatively,a Floquet state can be exploited to construct a qubit and two Floquet qubits can be entangled through a Controlled-NOT *** Floquet qubit offers robustness to background noise since there is always an oscillating electric field applied,and the single qubit operations are controlled by amplitude modulation of the oscillating field,which is convenient experimentally.

关键词： topological insulator quantum computing nanodevices

Genomic Mosaicism of the Brain:Origin,Impact,and Utility

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Neuroscience Bulletin 2024年第6期40卷 759-776页

作者： Jared h.Graham Johannes C.M.Schlachetzki Xiaoxu Yang Martin w.Breuss Department of Pediatrics Section of Clinical Genetics and MetabolismUniversity of Colorado School of MedicineAurora80045-2581COUSA Department of Cellular and Molecular Medicine University of California San DiegoLa Jolla92093-0021San DiegoCAUSA Department of Neurosciences University of California San DiegoLa Jolla92093-0021San DiegoCAUSA Rady Children’s Institute for Genomic Medicine San Diego92123CAUSA

Genomic mosaicism describes the phenomenon where some but not all cells within a tissue harbor unique genetic ***,research focused on the impact of genomic mosaicism on clinical phenotype—motivated by its involvement in cancers and overgrowth *** recently,we increasingly shifted towards the plethora of neutral mosaic variants that can act as recorders of cellular lineage and environmental ***,we summarize the current state of the field of genomic mosaicism research with a special emphasis on our current understanding of this phenomenon in brain development and *** the field of genomic mosaicism has a rich history,technological advances in the last decade have changed our approaches and greatly improved our *** will provide current definitions and an overview of contemporary detection approaches for genomic ***,we will discuss the impact and utility of genomic mosaicism.

关键词： Genomics Brain development Brain homeostasis Genomic mosaicism