微波消解-电感耦合等离子体发射光谱法同时测定凉粉罐头中8种元素含量

目的 建立用微波消解-等离子体发射光谱法同时测定凉粉罐头中的砷、汞、铅、镉、锡、铁、铜、锌的方法。方法 采用微波方法消解凉粉罐头样品,将凉粉罐头样品均质均匀后,置于密闭容器内,加入一定量的硝酸、过氧化氢、放在微波消解系统内进行消解。结果 该法测定精度高,各元素的相对标准偏差 (RSD, n=11) 均＜2.5％,加标回收率为92.9%~108.8%。结论 该方法具有消解用试剂量少、操作简单、检测速度快,多元素同时测定,减少环境污染等优点。     

西非多点系泊FPSO波频运动预报研究

应用三维势流理论及非线性时域动力耦合分析方法,针对西非深水海域的一座多点系泊浮式生产储油装置(FPSO),在涌浪海洋环境下对其进行了时域耦合计算和频域短期预报计算,并与模型试验结果进行了对比,较好地预报了该FPSO的波频运动性能,包括垂荡、横摇和纵摇,从而为我国深水海洋工程方案设计研究提供了技术储备.     

一种新型波束可控的口径耦合天线

设计一种基于人工电磁结构（AMC）的新型口径耦合天线。对加载了AMC 结构的口径耦合天线进行仿真。 根据仿真结果,天线的工作频率为5.5GHz,辐射的波束指向21°时增益为6.4dB。文中对天线的参数进行分析,波束 的偏移角度与AMC 结构的有关。将AMC 结构变为一排,天线波束可以指向11°。根据天线单元构造1×2 的子阵, 阵列天线具有更高的增益和带宽,并可以有波束的偏移。 天线子阵工作在5.5GHz 时天线的波束指向为26°,增益 8.47dB。     

耦合量子比特退纠缠的研究

在马尔科夫环境下,利用共生纠缠度,研究了耗散环境中耦合量子比特纠缠态及纠缠突然死亡的性质。研究结果表明：(1）纠缠动力学演化与系统的温度、初始纠缠度及初始量子态密切相关;（2）在一般情形下,由于环境的影响,纠缠突然死亡总会发生;通过数值模拟,发现存在一个特定的区域,在这区域内系统的纠缠度衰减的很慢。在零温度近似下,给出了具体的纠缠突然死亡条件和计算纠缠突然死亡时间的表达式。     

关于全耦合的一道习题的讨论

本文从关于全耦合的一道习题入手,分别从耦合电感的去耦等效、全耦合变压器的伏安关系、耦合电感等效为流控电压源和磁路及互感的定义出发,讨论了四种解法,剖析了其中的联系。本文的讨论对于深化学生和教师对去耦等效、全耦合变压器、变压器等效电路、磁路和互感定义的理解有一定帮助。     

正常人与胃癌患者尿液中6种微量元素的比较研究

目的比较胃癌患者尿液中6种微量元素的差别。方法HNO3-HCl04（4：1,v／v）为消解体系,利用电感耦合等离子体发射光谱法测定正常人与胃癌患者尿液中锰、镍、铝、钻、铜、铬等6种微量元素的含量。结果胃癌患者尿液中锰、镍和钴降低显著,铜、铬升高显著,钼降低但无显著性差异。结论胃癌患者与正常人尿液中6种微量元素的水平有显著差别,起到预防、早期诊断及临床治疗胃癌的辅助作用,具有一定的临床意义。     

Cl2/BCl3感应耦合等离子体GaN刻蚀侧壁形貌研究

基于感应耦合等离子体干法刻蚀技术,对采用Cl2/BCl3气体组分下GaN刻蚀后的侧壁形貌进行了研究。扫描电镜(SEM)结果表明,一定刻蚀条件下,刻蚀后GaN侧壁会形成转角与条纹状褶皱形貌。进一步实验,观察到了GaN侧壁转角形貌的形成过程;低偏压功率实验表明,高能离子轰击是GaN侧壁转角与条纹状褶皱形貌形成的原因。刻蚀过程中,掩蔽层光刻胶经过高能离子一段时间轰击后,其边缘首先出现条纹状褶皱形貌,并转移到GaN侧壁上,接着转角形貌亦随之出现并转移到GaN侧壁上。这与已公开发表文献认为的GaN侧壁条纹状褶皱仅由于掩蔽层边缘粗糙所引起而非刻蚀过程中形成的解释不同。     

航天时间延迟积分CCD相机振动模糊图像的恢复

提出了一种对航天时间延时积分(TDI)电荷耦合器件(CCD)相机振动移变降质图像进行恢复的方法。首先介绍了TDI-CCD的工作原理及其对振动的敏感性,建立了TDI-CCD振动降质的点扩散函数(PSF)模型,指出振动对TDI-CCD相机的降质过程是空间移变的;然后提出了基于快速CCD的振动检测方法,在振动检测技术中,利用了一种改进的灰度投影算法计算振动参量;最后提出对降质图像进行逐行恢复的方法,并对模糊图像进行了恢复。分别对匀速直线运动和正弦振动进行了实验。用峰值信噪比(PSNR)作为评价标准,对恢复图像进行了评价。结果表明,匀速直线运动模糊图像的PSNR为33.98dB,恢复后其PSNR为41.14dB;正弦振动模糊图像的PSNR为39.68dB,恢复后其PSNR为45.12dB。     

A macroscopic approach for seismic damage transition within reinforced concrete wall–frame structures

The damage models proposed to date fail to identify the damage transition within one typical dual structural system, that is, wall–frame structures, under strong earthquakes. It's conceptually promising to combine a macroscopic global damage model physically with a simplified structural model that can characterize the interaction mechanism between the frame part and wall part of the structures. Thus, a macroscopic approach, with the integration of a macroscopic global damage model and a generalized shear–flexure coupled model, is proposed to have a closer insight into the damage transition within the wall–frame structures. The relation between the stiffness ratio and the ratio of vibration periods is established by introducing two stiffness‐based damage indicators and modal damage indexes. By this relation and the stiffness degradation in the frame part and wall part, the correlations between the modal damages, global damage, and the damages of the two parts are clarified. The combination of the damage indicators of the two parts with global damage is proved to be capable of capturing the damage transition during the dynamic redistribution of internal forces. The case study indicates that the damage predictions of the wall–frame structures are consistent with the interstory drift and proportions of failed components. The comparative study implies the efficiency of strengthening the link beams.     

A generalized method for estimating drifts and drift components of tall buildings under lateral loading

A generalized method for estimating the drifts of tall buildings composed of planar moment‐resisting frames and coupled shear walls under lateral loading is presented. This method establishes the stiffness equations at the story levels by assuming that all the nodes in the same floor of a planar lateral‐force‐resisting unit have an identical lateral displacement, an identical rotation component due to the axial deformations of the columns, and an identical rotation component due to the flexural and shear deformations of the beams. By adopting this simplification, the story drifts contributed by different types of deformations, namely, the axial deformations of the columns or wall piers, the flexural and shear deformations of the beams, and the double‐curvature bending and shear deformations of the columns or wall piers, can be identified. In the formulation of the stiffness matrix, the P‐Delta effects were also incorporated. Through comparisons between the lateral displacements and story drifts computed using the proposed method and those computed using the structural analysis software Midas/Gen, the proposed method is proved to have high accuracy in estimating the drifts of tall building structures.