Temperature Dependent In-Plane Anisotropic Magnetoresistance in HfTe_5 Thin Layers

We report the observation of in-plane anisotropic magnetoresistance and planar Hall effect in non-magnetic HfTe₅ thin layers.The observed anisotropic magnetoresistance as well as its sign is strongly dependent on the critical resistivity anomaly temperature T_p.Below T_p,the anisotropic magnetoresistance is negative with large negative magnetoresistance.When the in-plane magnetic field is perpendicular to the current,the negative longitudinal magnetoresistance reaches its maximum.The negative longitudinal magnetoresistance effect in HfTe₅ thin layers is dramatically different from that induced by the chiral anomaly as observed in Weyl and Dirac semimetals.One potential underlying origin may be attributed to the reduced spin scattering,which arises from the in-plane magnetic field driven coupling between the top and bottom surface states.Our findings provide valuable insights for the anisotropic magnetoresistance effect in topological electronic systems and the device potential of HfTe5 in spintronics and quantum sensing.     

圆截面激光晶体热变形的弹性力学分析

采用热弹性理论建立了关于激光晶体热变形的微分方程和边界条件;对方程进行简化并利用级数法和伽辽金法进行求解,得到了圆截面激光晶体热变形的解析表达式。分析结果表明:晶体内的热变形是坐标r、z的非线性函数;变形与弹性模量E无关,而与晶体的尺寸、泊松比、热传导系数有关。     

Sr_3Gd(PO_4)_3∶Tm~(3 )的真空紫外光谱特性

研究了Sr3Gd(PO4)3∶Tm3 和GdPO4∶Tm3 样品的结构特性、光谱特性。GdPO4∶Tm3 为单斜晶系,基质掺入铥离子后结构没有明显变化。GdPO4∶Tm3 在164和210nm附近有强烈的吸收峰。位于164nm附近的强烈的吸收峰是归因于基质的吸收引起,210nm附近的吸收峰则归因于Gd3 的8S7/2—6GJ的能级跃迁。在164nm真空紫外光激发下,样品于453及363nm处有较强的发射峰,发射主峰位于453nm,属于Tm3 的1D2→3H4(22,123cm-1)跃迁的典型发射。由于阳离子质量的不同,Sr3Gd(PO4)3∶Tm3 在166nm附近的激发峰高于GdPO4∶Tm3 的同位置的激发峰,其在363nm处的发射有明显减弱,而在453nm处的蓝色发射有显著的增强。     

在线自发电源激发的流动注射电致化学发光测定异烟肼

采用了一种与流动注射体系组合的在线自发电池作为电致化学发光的激发源（ 简称FI－GCECL）。实验发现在碱性介质中，Al/Ag双金属对可以提供稳定的电位输 出并可激发鲁米诺在铂电极表面的电致化学发光。此自发电池具有使用寿命长、电 位可由碱性介质组成调节、可组合到流动注射体系中等特点，利用这种组合体系， 检测了三家厂生产的片剂中的异烟肼含量，将结果与药典标准方法进行了比较，证 明了这种电致发光分析的可行性。     

Kondo-Fano Effect in T-shaped Double Quantum Dots Coupled to Ferromagnetic Leads

Using an equation-of-motion technique,we theoretically study the Kondo-Fano effect in the T-shaped double quantum dots coupled to two ferromagnetic leads by the Anderson Hamiltonian.We calculate the density of states in this system by solving Green function.Our results reveal that the density of states show some noticeable characteristics not only depending upon the interdot coupling t ab,the energy level ε d1 of the side coupled quantum dot QD b,and the relative angle θ of magnetic moment M,but also the asymmetry parameter α in ferromagnetic leads and so on.All these parameters greatly influence the density of states of the central quantum dot QD a.This system is a possible candidate for spin valve transistors and may have potential applications in the spintronics.     

CaMgSi_2O_6∶Eu的真空紫外光谱特性

采用高温固相反应利用原料CaCO3,MgO,SiO2和Eu2O3合成了CaMgSi2O6∶Eu3 样品,并研究了其结构特性、光谱特性。CaMgSi2O6∶Eu3 属于单科晶系,基质掺入Eu离子后结构没有明显变化。CaMgSi2O6∶Eu3 在147nm真空紫外光激发下呈红色发射,发射主峰位于611nm,是Eu3 的5D0→7F2跃迁的典型发射。当Eu3 的相对摩尔浓度在0.02到0.10mol之间变化时,由相关数据可以发现有浓度猝灭现象发生。CaMgSi2O6∶Eu2 在172nm真空紫外光激发下呈蓝色发射,发射主峰位于452nm,是Eu2 的5d→4f跃迁的典型发射。添加不同浓度的H3BO3后可大大提高样品的发光强度。     

Sr3Gd(PO4)3:Tm3+的真空紫外光谱特性

研究了Sr3Gd(PO4)3 : Tm3 和GdPO4 : Tm3 样品的结构特性、光谱特性.GdPO4 : Tm3 为单斜晶系,基质掺入铥离子后结构没有明显变化.GdPO4:Tm3 在164和210 nm附近有强烈的吸收峰.位于164 nm附近的强烈的吸收峰是归因于基质的吸收引起,210 nm附近的吸收峰则归因于Gd 的8S7/2-6GJ的能级跃迁.在164 nm真空紫外光激发下,样品于453及363 nm处有较强的发射峰,发射主峰位于453nm,属于Tm3 的1D2→3H4(22,123 cm-1)跃迁的典型发射.由于阳离子质量的不同,Sr3Gd(PO4)3:Tm3 在166 nm附近的激发峰高于GdPO4: Tm3 的同位置的激发峰,其在363 nm处的发射有明显减弱,而在453 nm处的蓝色发射有显著的增强.     

致密油藏液测应力敏感性计算模型

综合成藏地质学、岩石力学和渗流力学,建立准确可靠的致密油藏考虑边界层、临界喉道和孔喉分布的液测应力敏感性计算模型.由于大庆油田致密油藏孔喉分布范围比长庆油田更窄,导致大庆油田应力敏感性更强,因此大庆油田产能更低.本文从微观角度定量表征了真实油藏中应力敏感性的作用机理.     

Spin-polarized transport through the T-shaped double quantum dots

Using the Keldysh nonequilibrium Green function and equation-of-motion technique, this paper investigates the spin-polarized transport properties of the T-shaped double quantum dots （DQD） coupled to two ferromagnetic leads. There are both Fano effect and Kondo effect in the system, and due to their mutual interaction, the density of states, the current, and the differential conductance of the system depend sensitively on the spin-polarized strength. Thus the obtained results show that this system is provided with excellent spin filtering property, which indicates that this system may be a candidate for spin valve transistors in the spintronics.