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.

Vibrational modes in La2Zr2O7 pyrochlore irradiated with disparate electrical energy losses

Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic energy loss(d E/dx)e increases from about 5.2 keV/nm to 39.6 keV/nm. The ion fluence ranges from 1× 10^11 ions/cm^2 to 6× 10^15 ions/cm^2.Vibrational modes of irradiated pyrochlore are analyzed by using Raman spectrum. Infrared active modes F1 uat 192, 308,and 651 cm^-1 appear in Raman spectra, and the F2 gband at 265 cm-1 rises up due to the irradiation by 200-MeV Kr ions with(d E/dx)e of 16.0 keV/nm. Differently, for the pyrochlore irradiated by 1750-MeV Bi ions with(d E/dx)e of 39.6 keV/nm, in spite of the appearance of infrared active mode F1 u651 cm^-1, the amorphous structure occurs according to the vibrational mode variations of pyrochlore irradiated at higher ion fluences. Amorphous tracks are observed in the samples, which confirm the occurrence of pyrochlore–amorphous transition in pyrochlore irradiated with(d E/dx)e of 39.6 keV/nm.

Implementation of ternary Shor's algorithm based on vibrational states of an ion in anharmonic potential

It is widely believed that Shor＇s factoring algorithm provides a driving force to boost the quantum computing research.However, a serious obstacle to its binary implementation is the large number of quantum gates. Non-binary quantum computing is an efficient way to reduce the required number of elemental gates. Here, we propose optimization schemes for Shor＇s algorithm implementation and take a ternary version for factorizing 21 as an example. The optimized factorization is achieved by a two-qutrit quantum circuit, which consists of only two single qutrit gates and one ternary controlled-NOT gate. This two-qutrit quantum circuit is then encoded into the nine lower vibrational states of an ion trapped in a weakly anharmonic potential. Optimal control theory（OCT） is employed to derive the manipulation electric field for transferring the encoded states. The ternary Shor＇s algorithm can be implemented in one single step. Numerical simulation results show that the accuracy of the state transformations is about 0.9919.

Accurate all-electron calculation on the vibrational and rotational spectra of ground states for O2 and its ions

The potential energy curves, spectroscopic constants, and low-lying vibration–rotation levels of ground-state O2 and its cation O2+ and anion O2- were calculated with the explicitly correlated multireference configuration interaction method.The zeroth-order reference wavefunction was treated with the complete active space multiconfigurational self-consistent field method, in which the active space was carefully selected, and an additional molecular orbital πu was added into the full valence active space.The electron correlation of the 1s core in the oxygen atom was considered in the computations.The Davidson correction on molecular energy was considered to account for higher electron excitation.The relativistic effects, including the scalar relativistic effect and spin–orbit coupling, were considered in the computation of potential energy curves.These physical effects on the spectroscopic constants were examined.The low-lying levels of vibration–rotation spectra of O2 and its ions were determined based on the computed potential energy curves.Comparisons with available experiments were made and excellent agreement was obtained for the vibrational and rotational parameters.The spectroscopic constants and vibration–rotation spectrum of O2-, which is sparse in experiments, were provided.Our study will shed some light on further theoretical and experimental studies on these simple but important molecular systems.

H_(2)S^(+)在A^(2)A_(1)(v1=1,v2=8,v3=0)激发态的光解动力学

振动激发在分子和离子的光解动力学中有着重要的作用:开展特定振动激发态分子离子的光解离动力学实验研究存在很大挑战,尤其是实现合频振动激发离子的量子态选择的制备.本文利用时间切片离子速度成像技术研究了H_(2)S^(+)离子经A^(2)A_(1)(v1=1,v2=8,v3=0)激发态解离生成S^(+)(4S)和H_(2)的光解动力学.实验结合多光子电离和共振激发技术制备了振动激发的H_(2)S^(+),获得了离子在357.02~358.38nm范围内六个光解波长下产物S^(+)的速度影像.根据实验影像,获得了产物的总平动能谱和不同转动态的角分布各项异性参数特别指出地是在很窄的光解能量范围内,转动产物H2(J=1)和H_(2)(J=3)的分支比出现多次反转,该现象与A^(2)A_(1)态单一振动模式激发的H2S+离子的光解动力学行为有明显不同.该研究表明,合频振动激发的H_(2)S^(+)离子光解动力学中可能存在振动模式之间的协同效应.

FT-Raman Spectroscopic Studies on the Interaction of Metal Ions With Sphingomyelin Bilayer

The interaction of trivalent lanthanide ions and divalent calcium ions with sph-'ngomyelm bilayer has been studied by FT-Raman spectroscopy.The results showed that the bonding of metal ions to the phosphate group of sphingomyelin bi-iayer,either La3+or Ca2+did not change the conformation of the choline group,that is,O-C-C-N+is still in its gauche conformation.The presence of metal ions changed the states of the interfacial region from liquid-like to amorphous state and even to crystalline.They increased the fluidity of acyl chains of sphingomyelin bilaver and made them packed disorderly.

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.

Generation of Arbitrary Pure States for Three-dimensional Motion of a Trapped Ion

在这份报纸，我们为产生一个套住的离子的震动的运动的一个任意的三维的纯状态建议一个计划。我们的计划基于激光脉搏的一个序列，它关于适当电子转变被调节到适当震动的边带。

Investigation of electron localization in harmonic emission from asymmetric molecular ion

We theoretically investigate the electron localization around two nuclei in harmonic emission from asymmetric molecular ion. The results show that the ionization process of electron localized around one nucleus competes with its transfer process to the other nucleus. By increasing the initial vibrational level, more electrons localized around the nucleus D＋ tend to transfer to the nucleus He2＋ so that the ionizations of electrons localized around the nucleus He2＋ increase. In this case, the difference in harmonic efficiency between Hell2＋ and HeD2＋ decreases while the difference in harmonic spectral structure increases. The evident minimum can be observed the spectral structure of HeD2＋, which is due to the strong in the harmonic spectrum of Hell2＋ compared with that in interference of multiple recombination channels originating from two nuclei. Time-dependent nuclear probability density, electron-nuclear probability density, double-well model, and time-frequency maps are presented to explain the underlying mechanisms.

Synthesis and electrochemical properties of LiNi_(0.8)Al_(0.2-x)Ti_xO_2 cathode materials by an ultrasonic-assisted co-precipitation method

A new co-precipitation route was proposed to synthesize LiNi0.8A10.2-xTixO2 （x=0.0-0.20） cathode materials for lithium ion batteries, with Ni（NO3）2, Al（NO3）3, LiOH·H2O, and TiO2 as the starting materials. Ultrasonic vibration was used during preparing the precursors, and the precursors were protected by absolute ethanol before calcination in the air. The influences of doped-Ti content, calcination temperature and time, additional Li content, and ultrasonic vibration on the structure and properties of LiNi0.8A10.2-xTixO2 were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and charge-discharge tests, respectively. The results show that the optimal molar fraction of Ti, calcination temperature and time, and additional molar fraction of Li for LiNi0.8A10.2-xTixO2 cathode materials are 0.1,700℃, 20 h, and 0.05, respectively. Ti doping facilitates the formation of the α-NaFeO2 layered structure, and ultrasonic vibration improves the electrochemical performance of LiNi0.8A10.2-xTixO2.

磷酸铁锂正极材料的功能化研究现状及展望

阐述了磷酸铁锂正极材料固有缺陷的形成原因,重点介绍了碳包覆、体相掺杂、颗粒纳米化、调控微观形貌等改性手段对磷酸铁锂正极材料相关性能的影响,最后展望了磷酸铁锂正极材料在不同应用场景的发展趋势。

柱棒式超磁致伸缩能量收集器的设计与实验

为了能够利用自然界中的振动能量,弥补传统微器件供能方式的不足。设计制作了一种以超磁致伸缩材料(GMM)为基础的振动能量收集装置,并通过实验加以验证其能量收集特性;首先,通过对超磁致伸缩材料物理特性的分析,进行了能量收集装置理论建模与仿真分析;然后,根据仿真分析的结果设计了一套柱棒式的超磁致伸缩能量收集器;最后,通过搭建实验平台进行了效果验证。实验结果表明:当输入激振信号频率f_n不变,振动能量收集装置输出电压峰-峰值和输入振动信号的幅值F_m成正比;当输入振动信号幅值F_m不变,振动能量收集装置输出电压峰-峰值和输入激振信号的频率fn成正比;在激振应力最大值为2.54 MPa、频率100 Hz的正弦激振条件下,感应线圈100匝的实验条件下,超磁致伸缩振动能量收集器输出电动势峰-峰值为136.4 mV,与理论值(156 mV)符合较好,且波形一致。

机械振动对挤压铸造A356铝合金组织与性能的影响

研究了挤压铸造过程中机械振动对A356铝合金材料显微组织与力学性能的影响规律,并对机械振动击碎枝晶的作用机理进行了阐述。结果表明:施加机械振动能够有效地消除材料缩松缩孔及断面裂纹,减少甚至消除挤压铸造铝合金铸锭的微观孔洞,细化晶粒组织,使得组织更加均匀;挤压铸造凝固初期,机械振动能够在很大程度上破碎二次枝晶臂,增加材料的形核率;试验值与理论值的对比分析表明,Kirkwood模型具有更高的精度;机械振动能够提高材料的力学性能,相较于重力铸造与无振动挤压铸造而言,所得铸件的抗拉强度与延伸率均有一定提高.

双转子系统动静碰摩动力学研究与基于振动加速度的实验验证

基于航空发动机动静碰摩故障的特点,建立双转子系统动静碰摩的动力学模型。模型中充分考虑机匣与轮盘碰撞时的弹性变形、接触渗透及弹性阻尼支撑,应用Hertz接触理论和库伦模型,建立干摩擦情况下双转子系统动静碰摩故障时的运动微分方程。运用四阶经典Runge-Kutta法进行求解,得到碰摩故障下双转子系统的动力学响应。因为实际的航空发动机转子的振动位移不易获取,多是测得轴承座或者机匣的振动加速度,为了提取碰摩状态下轴承座振动加速度特征,建立双转子系统试验台,进行动静碰摩实验,从轴承座测量振动加速度,通过频谱分析和包络谱分析方法,分析了轴承座振动加速度信号中的碰摩特征。结果表明双转子系统动静碰摩时,可将两个激励源的倍频和组合频率成分作为航空发动机动静碰摩故障的典型特征。而且当两个振源的频率值相互接近到20%的时候,双转子系统拍振信号强度较大。动力学仿真和实验取得了很好的一致性,验证了所提出的双转子系统碰摩模型的正确有效性。

某异形拱人行桥通行舒适度及其控制研究

综合对比了国内外规范对于人行桥通行舒适度的规定,并以一座异形拱人行桥为研究背景,利用大型通用有限元分析软件Midas civil建立背景工程的有限元模型;参考德国人行桥设计规范中的舒适度评价方法对人行桥进行舒适度评价,并利用调谐质量阻尼器对人行桥进行减振设计.通过对背景工程进行舒适度评价和减振设计,得到一些实用设计分析有益的结果,分析结果表明:本工程在一般的正常使用情况下振动舒适性满足要求;当桥面上行人密度过大,行人交通荷载繁忙的极端状况下时,振动舒适性不能满足要求;采用TMD消能减振装置后,桥梁结构的动力响应均达到建议的峰值加速度范围以内,满足振动舒适性要求.

一种Stewart隔振平台的动力学建模及实验研究

提出一种采用石墨自润滑球铰连接的立方体构型Stewart隔振平台,6个支腿通过可转动的球铰与基础及载荷平台相连,每个支腿由音圈作动器与力传感器构成。在假设各支腿、基础及载荷平台均为弹性体的基础上,采用子结构频响函数综合法对Stewart隔振平台进行动力学建模,并通过FEM方法进行验证,给出内嵌反馈控制的隔振平台模型,对反馈控制效果进行仿真验证;在仿真分析的基础上,对隔振平台的被动隔振性能和内嵌反馈控制的主动隔振性能进行实验。结果表明,被动隔振在30~200 Hz频段内具有约-36 d B/dec的衰减率,主动隔振在3~100 Hz频段内可获得最大20 d B的幅值衰减,<200 Hz,支腿力RMS值控制后下降75%~80%。

双简谐式振动输送机动力学与传输特性研究

介绍一种先进的双简谐振动输送系统 ,并建立了系统的数学模型 ,理论分析和仿真表明该系统能产生慢进快退的机体运动 ,送料效果良好 ,还可以通过调节电机转速控制送料情况 ,实现正常送料、二分之一送料和不送料 ,现场实际的运料工况都与仿真结果相吻合。

振动对动物体内腹壁脂肪的耗散作用

本文叙述了振动对动物体内腹壁脂肪的消减作用，以频率为２０Ｈｚ，振幅为０．２ｃｍ的振源作用于鸡的腹壁脂肪部位的一侧，而另一侧为对照侧，每个动物的实验期为一星期，当振动作用累积１３．５小时后，发现振动直接作用侧的脂肪厚度明显地低于对照侧的厚度，二者相差大于２１％，同时在１／４的样本中发现腹壁脂肪中出现乳化和深壁沟纹现象。实验结果对生物力学的基础理论和人体减肥机制的研究提供了有益的参考。

3200mm轧机主传动系统扭振研究

通过仿真计算 ,研究了 32 0 0mm中厚板轧机主传动系统的扭振问题 ,得出系统扭振的固有频率和主振型 ,其动态响应的基频与实测值比较符合 。

高浓度NaBF_4/DMF溶液中的离子溶剂化和离子缔合

利用振动光谱技术和量子化学方法研究了NaBF4/DMF溶液中的离子缔合和离子溶剂化现象。DMF分子的谱带变化表明,Na+ 与DMF分子的相互作用是通过DMF分子羰基上的氧原子进行的。Na+ 的溶剂化层内含有4个DMF分子,呈近似的四面体结构。而BF-4谱带的变化表明,溶液中存在着离子缔合,有直接接触离子对生成。直接接触离子对的含量随溶液浓度增加而增大。