微波消解-氢化物发生-原子荧光光谱法测定羊栖菜中汞

建立了微波消解-氢化物发生-原子荧光光谱法测定羊栖菜中汞的方法,系统地研究了微波消解、氢化物发生的最佳条件,利用加标回收试验,对分析方法进行了验证.本方法具有简便、快速、灵敏度高等优点,检出限为0.05μg/L,RSD为1.5%,样品加标回收率为93.8%-105.3%.     

Possible Realization of Cluster States and Quantum Information Transfer in Cavity QED via Raman Transition

We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another.     

Effect of Bias on Content of GeC in Ge1-xCx Films

Ge1-x Cx films with GeC content up to 11.6% can be prepared by using a medium frequency magnetron sputtering technique in our study. X-ray photoelectron analysis for these Ge1-x Cx films shows that the Ge1-x Cx films consist of C, Ge, GeC and GeOy. The content of GeC increases from 10.7% at 0 V to 11.6% at 250 V, and decreases to 9.6% at 350 V, and then increases again to 10.4% at 450 V. The Raman analysis confirms the result of XPS for checking GeC in the deposited Ge1-x Cx films. The related mechanism is discussed.     

Photoassociation of Atomic BEC within Mean-Field Approximation： Exact Solutions

We propose an exactly solvable method to study the coherent two-colour photoassociation of an atomic Bose- Einstein condensate, by linearizing the bilinear atom-molecule coupling, which allows us to conveniently probe the quantum dynamics and statistics of the system. By preparing different initial states of the atomic condensate, we can observe very different quantum statistical properties of the system by exactly calculating the quadrature- squeezed and mode-correlated functions.     

Controlled Teleportation of Multi-Qudit Quantum Information

We present a controlled teleportation scheme for teleporting an arbitrary superposition state of an M-qudit quantum system. The scheme employs only one entangled state as quantum channel, which consists of the qudits from Alice, Bob and every agent. The quantum operations used in the teleportation process are a series of qudit Bell measurements, single-qudit projective measurements, qudit H-gates, qudit-Pauli gates and qudit phase gates. It is shown that the original state can be restored by the receiver only on the condition that all the agents collaborate. If any agent does not cooperate, the original state can not be fully recovered.     

“小白礁Ⅰ号”清代木质沉船构件的脱盐监测

“小白礁Ⅰ号”是一艘沉没于清代道光(1821-1850)年间的远洋木质商船,其“中西合璧”的船体构造为社会所关注。脱盐保护处理主要采用10 mmol·L-1 EDTA-2Na为水溶液,NaOH配置成中性后,静水浸泡和去离子水循环相配合,周期性更换脱盐溶液的方式进行。选取浸泡脱盐中的“小白礁Ⅰ号”典型船体构件作为持续监测观察样本,定期采集脱盐浸泡液样品,通过连续为期一年的分析检测,全面监控评估船体构件的脱盐情况。利用分光测色计检测木材样品表面颜色变化;扫描电镜-能谱（SEM-EDS）观察木材样品微观形貌及元素变化;元素分析仪检测木材样品的硫元素含量、电感耦合等离子体质谱仪（ICP-MS）检测脱盐溶液的铁元素含量,评估以硫铁化合物为主的难溶盐脱除效果;离子色谱分析（IC）检测脱盐溶液中的阴阳离子含量,评估可溶盐的脱除效果。分光测色计测试结果表明,“小白礁Ⅰ号”船体构件整体的色差变化趋势较为稳定,色差变化不明显。扫描电镜-能谱（SEM-EDS）测试结果表明,以球状颗粒形态存在的硫铁化合物明显减少,难溶盐得到了有效的脱除。元素分析仪、电感耦合等离子体质谱仪（ICP-MS）测试结果表明,船体构件中硫含量降低到1 Wt%左右,脱盐溶液内的铁元素含量整体偏低,波动幅度不明显,且呈缓慢的下降趋势,后半段铁元素脱除率明显降低。离子色谱分析（IC）结果表明脱盐溶液中SO2-₄含量很低,变化小。K+,Mg2+和Ca2+已经基本检测不到。Cl-和Na+含量相对较高,是由脱盐试剂中含有这两种离子所致,停止投放试剂改换纯水浸泡可有效降低含量。Cl-和Na+含量虽然有所波动,但在长达一年的时间内总脱盐量变化幅度较小,大量可溶盐已被脱除。     

速率偏频激光陀螺过锁区误差特性分析

分析了速率偏频激光陀螺过锁区的误差特性。根据激光陀螺的闭锁方程,分别从数值模拟和理论分析两种途径对速率偏频激光陀螺过锁区误差特性进行了研究。结果一致表明:速率偏频激光陀螺过锁区的误差与锁区大小成正比,与过锁区的加速度的平方根成反比,与刻度因子的平方根成反比。文中具体给出了速率偏频激光陀螺过锁区的误差方程。过锁区误差为速率偏频激光陀螺的主要误差源。     

电力系统可靠性的蒙特卡洛方法

本文首先对中国科学技术大学管理科研楼电力系统可靠度评估建立了线性传感器模型。由于线性传感器可靠度评估是一个#P问题,没有多项式时间的算法。所以本文运用了蒙特卡罗方法,考虑到未加改进的蒙特卡洛方法对于解决本身可靠度很高的系统时的效率非常低,本文使用了广泛应用于网络可靠性的RVR(Recursive Variance Reduction)方法,给出了可靠度的测算结果。     

南沙群岛工程地质环境分区与质量评价

南沙群岛海区自然资源丰富,但工程地质条件复杂,地质灾害频繁。随着对该海区海洋资源的开发和其它海洋工程活动的增加,调查和研究其工程地质环境与质量评价就成为非常必要的前期工作。本文在分析了南沙群岛海区地质构造、活动断裂和火山地震活动的基础上,结合海洋水动力环境要素将南沙海区工程地质环境划分为5个区:南部陆架区、西部陆坡区、南沙海槽区、礼乐滩微陆块区、珊瑚礁隆起区,并深入分析了各分区的环境特征。     

非结构动网格在可动边界问题中的应用研究

本文对用于非结构动网格生成的弹簧近似方法进行了研究。通过采用顶点弹簧方法,分析研究了弹簧倔强系数的取值,同时通过引入挤压倔强系数和边界修正,对标准弹簧近似方法进行了改进。改进后的方法可以大大提高网格变形能力和网格质量。应用本文发展的非结构动网格生成方法并通过耦合求解基于(ArbitraryLagrangian-Eulerian ALE)描述的Euler方程,模拟了谐和振动NACA0012翼型及M6机翼的跨音速绕流,计算结果与参考文献提供的结果及实验结果吻合良好。