An Economical Magnetocardiogram System Based on High-To SQUIDs

An economical magnetocardiogram （MCG） system is built in our laboratory. It mainly consists of a MCG data acquisition stage equipped with two high-To superconducting quantum interference device （SQUID） magnetometers, a data processing stage with digital filtering and a one-layer μ-metal magnetically shielded room in conjunction with a high-Tc SQUID based active compensation. Experimental results show that a noise level of pico-tesla in MCG profiles, which is necessary for clinical applications, may be achieved with the system. Moreover, stable and convenient operations of the system are demonstrated with simulating MCG measurements.     

Control Method of Cooling a Charged Particle Pair in a Paul Trap

We propose a simple feedback cooling method, including both the component feedback and the velocity feedback,for cooling a charged particle pair in a Paul trap. It is found that the system can be cooled to periodic orbits;and if control intensity is strong, the system can be cooled to a one-periodic orbit, which is only in a horizontalplane. The result shows that the cooled system is also robust for noise.     

动态IP地址的捕获及应用

探讨了点对点TCP／IP连接、动态IP地址的捕捉与发布，介绍了动态IP地址捕捉发布工具-DynamIP，分析了DynamIP的应用实例。     

SDE-GC-μEGD分析水中挥发性卤代烃

运用微滴溶剂萃取-气相色谱-微池电子捕获检测器联用技术(SDE-GC-μECD)对水中挥发性卤代烃(vHH)的分析进行了可行性探讨,优化了微滴溶剂萃取技术的多种影响因素.方法在0.1～20μg/L之间呈线性,相关系数为0.999 1～0.999 8,相对标准偏差在1.2%～4.6%之间,加标回收率在83%～117%之间.该方法所用的有机溶剂很少(1～2 μL),装置简便,是值得推广的绿色环保、高效的前处理方法.     

SDE-GC-ECD分析水体中有机氯农药

运用单滴溶剂萃取-气相色谱-微池电子捕获检测器(SDE—GC—μECD)联用技术对水体中有机氯农药进行了分析，优化了影响单滴溶剂萃取的多种因素。该方法除了对P，P′-DDD的线性范围在0．4～4ng／mL之间外，其余的七种目标物(α-666，β-666，γ-666，δ-666，P，P′-DDE，0，P′-DDT，P，P′-DDT)线性范围均在0．04～4．0ng／mL之间，相关系数为0．9976～0．9999，回收率范围为83．3％～96．1％，相对标准偏差为2．1％～7．8％。与传统的液液萃取相比，单滴溶剂萃取不仅准确度、精密度相当，而且还具有省时、省溶剂的优点。     

用原子捕获技术提高火焰原子吸收光谱法的灵敏度

采用简易的石英原子捕获器，使Ｃｕ，Ａｇ，Ａｕ，Ｚｎ，Ｃｄ，Ｐｂ，Ｓｂ，Ｂｉ等易挥发元素在空气－乙炔火焰原子吸收光谱法中的灵敏度提高了３～５倍，并有较好的精密度，相对标准偏差在１％左右，方法中用此技术测定了标准物质中Ｐｂ、Ｃｄ的含量，获得了满意的结果，它较之石墨炉原子吸收光地具有快速，简便的特点，具有较大的实用价值。