Focusing phenomenon and near-trapped modes of SH waves

In this study, the null-field boundary integral equation method （BIEM） and the image method are used to solve the SH wave scattering problem containing semi-circular canyons and circular tunnels. To fully utilize the analytical property of Circular geometry, the polar coordinates are used to expand the closed-form fundamental solution to the degenerate kernel, and the Fourier series is also introduced to represent the boundary density. By collocating boundary points to match boundary condition on the boundary, a linear algebraic system is constructed. The unknown coefficients in the algebraic system can be easily determined. In this way, a semi-analytical approach is developed. Following the experience of near-trapped modes in water wave problems of the full plane, the focusing phenomenon and near-trapped modes for the SH wave problem of the half-plane are solved, since the two problems obey the same mathematical model. In this study, it is found that the SH wave problem containing two semi-circular canyons and a circular tunnel has the near-trapped mode and the focusing phenomenon for a special incident angle and wavenumber. In this situation, the amplification factor for the amplitude of displacement is over 300.

Trapped Modes in a Three-Layer Fluid

In this work,trapped mode frequencies are computed for a submerged horizontal circular cylinder with the hydrodynamic set-up involving an infinite depth three-layer incompressible fluid with layer-wise different densities.The impermeable cylinder is fully immersed in either the bottom layer or the upper layer.The effect of surface tension at the surface of separation is neglected.In this set-up,there exist three wave numbers:the lowest one on the free surface and the other two on the internal interfaces.For each wave number,there exist two modes for which trapped waves exist.The existence of these trapped modes is shown by numerical evidence.We investigate the variation of these trapped modes subject to change in the depth of the middle layer as well as the submergence depth.We show numerically that two-layer and single-layer results cannot be recovered in the double and single limiting cases of the density ratios tending to unity.The existence of trapped modes shows that in general,a radiation condition for the waves at infinity is insufficient for the uniqueness of the solution of the scattering problem.

Generation of Superpositions of Two-Mode Coherent States for the Motion of Two Trapped Ions

We propose a method for the generation of superpositions of two-mode coherent states for the center-of-mass and relative vibrational modes of two trapped ions. In the scheme the ions are driven by a single travelling-wave laser field tuned to the carrier. Then a measurement of the internal states collapses the vibrational modes to the entangled coherent state.

GCMS结合顶空Trap模式测定废液中酯类化合物

本文使用气相色谱质谱联用仪结合顶空Trap模式建立了废液中6种酯类化合物的测定方法.样品置于密封顶空瓶中,80℃平衡25 min后,Trap模式进行富集,经GCMS进行分析,以SIM方式进行采集,外标法定量.6种酯类化合物在10-200μg·L^(−1)的浓度范围内相关系数R在0.999以上.10μg·L^(−1)标准溶液放入6个20 mL顶空瓶中连续进样,峰面积RSD%为1.6%-3.9%.该方法简单易操作,富集效率高,是废液中酯类化合物的有效分析方法.

Quasi-coherent mode in core plasma of SUNIST spherical tokamak

A quasi-coherent(QC)mode was observed in the core region of low-density ohmic plasmas in Sino-UNIted Spherical Tokamak.In experiments on the QC mode,two sets of moveable Langmuir probes(LPs)were used to measure the local parameters including floating potential,electron temperature,electron density,and so on,as well as their profiles.To monitor the magnetohydrodynamic activities,a Mirnov probe was used to measure the poloidal magnetic fluctuation.The QC mode can be seen in the spectra of floating potential,but there is no similar peak in the spectra of magnetic fluctuation.Thus,the QC mode is probably electrostatic.By analyzing the electrostatic potential fluctuations from the LPs,the features of the QC mode including frequency,wavenumber,propagation direction,and dependence on collisionality are identified,which are consistent with the characteristics of dissipative trapped electron mode.

Damping of Geodesic Acoustic Mode by Trapped Electrons

We study the Landau resonance between geodesic acoustic mode（GAM） and trapped electrons as a GAM’s collisionless damping. The assumption of ˉωde 〈〈ωbeis adopted.The damping rate induced by trapped electrons is found to be an increasing function of q. In low q range, circulating-ion-induced damping rate is larger than that induced by trapped electrons.As q increases, the latter becomes larger than the former. The reason is that trapped electrons’ resonant velocity is close to vtefrom the lower side, whiles circulating ions’ resonant velocity gets bigger further from vti. So the number of resonant trapped electrons increases, whiles the number of resonant circulating ions decreases. The amplitude of damping rate induced by trapped electrons in the edge plasma can be comparable to that induced by circulating ions in the low q range.Another phenomenon we found is that in the chosen range of, the damping caused by trapped electrons has a maximum value at point εq for different q. The reason is that as is close to q,trapped electorns’ resonant velocity is close to vte.

Analysis of thickness-shear and thickness-twist modes of AT-cut quartz acoustic wave resonator and filter

The thickness-shear （TS） and thickness-twist （TT） vibrations of partially electroded AT-cut quartz plates for acoustic wave resonator and filter applications are theoretically studied. The plates have structural variations in one of the two in-plane directions of the plates only. The scalar differential equations derived by Tiersten and Smythe for electroded and unelectroded AT-cut quartz plates are used, resulting in free vibration resonant frequencies and mode shapes for both fundamental and overtone fam- ilies of modes. The trapped modes with vibrations, mainly confined in the electroded areas, are found to exist in both the resonator and the filter structures. The numerical results for the trapped modes are presented for different aspect ratios of electrodes and material properties, providing a reference to the design and optimization of quartz acous- tic wave resonators and filters.

Exploration of Subtle Trap in Jiyang Depression

This article analyses the procedure of exploration of the Tertiary subtle trap in Jiyang depression and divides the Tertiary subtle trap into 3 types (lithologic reservoir, stratigraphic reservoir and fractured reservoir) and 8 groups, then summarizes the common feature and founding discipline of the subtle trap and finds 4 accumulating modes including steep slope mode, depression mode, center anticline mode and gentle slope mode. Its main exploration methods are explicated from the viewpoint of reservoir geological modeling, description of recognizing traps and comprehensive evaluation of reservoir and so on.

3D Numerical Modeling of Wave Forces on Tandem Fixed Cylinders Using the BEM

在这糊 3D 数字模型被开发学习在波浪之间的复杂相互作用，一套双人脚踏车修理了柱体。液体被认为是 inviscid 并且无旋。因此， Helmholtz 方程被用作一个管理方程。边界元素方法(BEM ) 被采用到 discretize 相关方程。开的边界在学习领域的远领域里被使用。线性波浪被产生并且向双人脚踏车宣传了固定柱体估计力量在他们上适用。特殊注意在在力量上改变在柱体， ka 和 kd 之间的非维的柱体半径和距离上对效果的考虑被给予并且套住模式。在一套九双人脚踏车柱体的中间的柱体波浪力量和套住的模式被验证利用分析数据。比较证实模型的精确性。n 双人脚踏车柱体上的嵌入的波浪力量评价的结果证明在排的批评柱体是为柱体的奇数的中间的。而且，批评套住的模式效果发生为的结果表演近把柱体半径规范化为 0.5 和 1.0。最后，为 n 双人脚踏车柱体的力量评价证实中间的柱体对规范的分离距离的那个力量振幅关于单个柱体的波动。

ELECTRICALLY FORCED VIBRATION OF A THICKNESS-TWIST MODE PIEZOELECTRIC RESONATOR WITH NON-UNIFORM ELECTRODES

We study the effect of electrodes with varying thickness on thickness-twist vibration of a piezoelectric plate resonator of crystals of 6 mm symmetry. An exact theoretical analysis is performed. Results show that non-uniform electrodes have a strong effect on mode shapes, and suggest the possibility of using nonuniform electrodes for strong energy trapping.

Generation and Properties of Two-Mode Circular States

Two-mode circular states,which are superposition states from some two-mode coherent states,are studiedtheoretically.It is shown that under certain conditions two-mode circular states may exhibit nonclassical effects,suchas sub-Poissonian statistics and intermode correlation.We propose schemes to generate two-mode circular states by theinteraction of a trapped ion with traveling wave lasers.

Generation of Vibrational Entangled Coherent States of Two Trapped Ions

We propose a scheme for the generation of entangled coherent states for the center-of-mass and relative vibrational modes of two trapped ions. In the scheme the ions are simultaneously illuminated by a single standing-wave laser tuned to the carrier. The scheme allows the production of an entangled coherent states with a considerably high speed as long as a laser field of sufficiently high intensity is available.

A scheme of quantum phase gate for trapped ion

We propose a scheme to implement two-qubit controlled quantum phase gate（CQPG） via a single trapped two-level ion located in the standing wave field of a quantum cavlty, in which the trap works beyond the Lamb--Dicke limit. When the light field is resonant with the atomic transition ｜g） →← ｜e） of the ion located at the antinode of the standing wave, we can perform CQPG between the internal and external states of the trapped ion; while the frequency of the light field is chosen to be resonant with the first red sideband of the collective vibrational mode of the ion located at the node of the standing wave, we can perform CQPG between the cavity mode and the collective vibrational mode of the trapped ion. Neither the Lamb--Dicke approximation nor the assistant classical laser is needed. Also we can generate a GHZ state if assisted with a classical laser.

Kinetic Theories of Geodesic Acoustic Modes：Radial Structure,Linear Excitation by Energetic Particles and Nonlinear Saturation＇

Geodesic acoustic modes（GAMs）are oscillating zonal mode structures unique to toroidal plasmas and are capable of regulating microscopic turbulence and associated transports.Inthispaper,three important aspects of GAM dynamics are investigated,namely（1） GAM continuous spectrum and its mode conversion to kinetic GAM （KGAM）;（2） 1inear excitation of energetic particle induced GAM （EGAM） and its coupling to the GAM continuum, and （3） nonlinear saturationofEGAMviawaveparticletrapping.TheanalogybetweentheGAM

北部湾盆地迈陈凹陷涠洲组扇体发育特征与成藏

北部湾盆地迈陈凹陷是典型的南断北超的箕状断陷,发育“南扇北洲”沉积体系。南部断裂带—深凹带钻井揭示扇根水道、扇中水道等沉积微相,研究认为涠洲组发育多期叠置的大型扇体,可划分为5套扇体组合,细分为18期扇体。受构造、沉积演化的控制,迈陈凹陷发育的扇体可形成扇根遮挡型、上倾尖灭型、断层-岩性型3种类型圈闭。南部扇体具有良好的成藏配套条件,深凹带烃源岩厚度大、成熟度高,长期处于增熟排烃过程;多套泥岩盖层与扇中砂岩形成良好储盖组合;涠二段至涠三段中上部发育优质扇中砂岩储层;深凹带排烃早、油气充注时间更长,有利于形成富集规模油藏。因此,迈陈凹陷断裂带—深凹带扇体隐蔽圈闭是获得规模储量的重要勘探领域。

传播模式视角下的“塔西佗陷阱”解析与应对

“塔西佗陷阱”研究呈现出主题多、分布广以及零散性和趋量少的特点,这与现代风险意识的常态化和研究上的社会性、系统性要求不相符。传播学的模式思维适合这种要求,但目前传播模式研究是“塔西佗陷阱”研究的薄弱环节。在分析以往传播模式研究的基础上,构建全方位、系统性的“塔西佗陷阱”模式,不仅可以精准把握该现象可能出现的具体环节和细节,还可以实现社会风险传播管理层面的现代化、规模化、精确化。

褶皱衍射光栅提升绿光量子点发光二极管的光耦合输出效率

为了解决绿光量子点发光二极管(QLED)基底模式陷入光问题,首先通过在柔性聚二甲基硅氧烷基底上蒸镀铝层,自发形成了准周期褶皱结构。这种简单、有效的方法可以制作大面积的褶皱结构,所制作的褶皱结构具有随机取向和宽周期分布的特点。然后,将褶皱结构作为外结构引入到QLED中,构筑了高效的绿光QLED。与参考QLED相比,褶皱QLED的外量子效率(EQE)从12.09%增加到16.06%,提升了32.8%;最大亮度从184600cd·m^(-2)增加到226500cd·m^(-2),在不改变发光峰位的情况下实现了基底模式陷入光的高效提取,为提升绿光QLED性能提供了一种新的选择。

640×512规模碲化汞量子点中波红外焦平面阵列(特邀)

中波红外成像在军事侦察、遥感测绘、航天航空等领域发挥了重要作用。现有中波红外焦平面主要采用碲镉汞、二类超晶格、锑化铟等块体半导体材料,其性能优异、稳定性高。然而,其复杂的材料制备及倒装键合工艺限制了块体半导体焦平面阵列的批量化制备及低成本应用。胶体量子点作为一种新兴液态半导体材料,具有光谱调控范围“宽”、合成规模“大”、制备成本“低”、以及加工工艺“易”等优势,为新型红外焦平面阵列研发提供了全新的思路。碲化汞量子点采用“热注法”合成,并通过旋涂方法实现与硅基读出电路的直接电学耦合,阵列规模及像元间距为640×512及15μm。在80 K工作温度下对焦平面阵列进行了性能测试,碲化汞焦平面阵列响应截止波长达到4.6μm、比探测率为2×10^(10)Jones、噪声等效温差51.26 mK(F#=2)、响应非均匀性3.42%且有效像元率高达99.99%,展现了较好的成像性能,为非倒装键合体制中波红外成像焦平面的制备提供了新的方案。

北部湾盆地海中凹陷成藏关键要素及成藏模式

海中凹陷经几十年勘探虽点上有发现,但因成藏关键要素不明勘探陷入了停滞。该文为寻求其勘探规模突破方向,在成凹、成烃研究的基础上,深化成藏关键要素研究,建立了海中凹陷成藏模式,指出了规模突破的勘探有利区带。研究认为:海中凹陷油气成藏关键要素是近生烃中心、圈源时空匹配佳、油气输导条件好、优质储层发育。北部陡坡带是各成藏关键要素匹配最佳区,是海中最有利的勘探区带。研究成果为寻求海中凹陷规模油气突破指明了方向。

离子阱在不同真空条件下的离子出射方式研究

离子阱质谱在质量分析中取得了越来越广泛的应用。在质量分析过程中有多种对离子阱的操作模式,不同操作模式造成了离子的出射方式不同。质谱分析过程中腔室对于真空度的要求较高。基于离子运动理论,通过选取合适的碰撞模型,从10-3 Pa到100 Pa的压强条件下对离子使用不同出射方式进行仿真。探究了不同出射方式下各种条件对质量分辨率的影响。仿真发现:在使用射频电压(radio frequency,RF)扫描和辅助交变(alternating current,AC)电压恒定的电压施加方式时,质量分辨率受到离子碰撞概率和交变电场施加的动能的共同影响。同时施加合适的辅助交变扫描电压可以避免离子提前激发或者弛豫滞后激发,进一步提高分辨率。目前尚未有对这一理论的定量分析。最后通过优化出射方式,仿真实现了在100 Pa的压强下取得220的质量分辨率。相比于边界不稳定出射将质量分辨率提升了185%。