S波段微波热致超声成像系统研究

微波热致超声成像技术通过向物体发射微波脉冲, 导致物体吸收电磁波温度迅速升高, 产生瞬时压力波, 从而激发产生超声波信号, 通过传感器对产生的超声波信号进行采集并成像, 最终还原了反映物体吸收电磁波能量特性的图像, 由于此方法兼具了微波成像的高对比性和超声成像的高分辨率特点, 理论上验证了热声成像技术对早期乳腺肿瘤检测的可行性. 本实验兼顾系统成像深度和分辨率, 采用S波段的微波脉冲信号源对物体进行辐射, 利用圆形扫描方式对待测物体进行检测, 同时为了更好的验证成像性能, 本实验同时使用了肿瘤仿体及实际生物组织进行成像实验. 通过实验分析, 验证了该系统对肿瘤仿体和生物组织检测的有效性, 以及系统的高分辨率和高对比度特性, 为早期乳房肿瘤检测提供了进一步的理论支撑.     

烷氧基桥联双三联吡啶的简洁合成

通过2,2'-烷氧基双苯甲醛或4,4'-烷氧基双苯甲醛和2-乙酰基吡啶在氢氧化钠和氨水溶液中的一锅煮串联反应,方便地合成了一系列重要的烷氧基桥联的双三联吡啶配体.产物结构通过1HNMR,13CNMR和HPLC/MS表征,并测定了一个代表性化合物的单晶分子结构.     

X-Ray Radiation Characteristics of Nested-Wire Array Implosion in Sino-Russian Joint Z-pinch Experiments on Angara-5-1

We report and discuss the results of x-ray radiation measurements in the Sino-Russian joint Z-Pinch experiments on Angara-5-1 facility with a load current of 2.5-3.6MA. The measurements were conducted by using an x-ray power meter (XRPM) and a time-resolved one-dimensional x-ray imaging system developed in China Academy of Engineering Physics. The experimental results indicate that an x-ray power-platform prior to a main peak and a less intensive sub-peak after the main peak in the waveform exist for the nested-wire array implosions, and the radiation process is relatively faster than that in the case of the single array. Laser shadowgraph of the imploding plasma suggests that the prior power-platform is a result of the collision of the inner-outer plasma layers. The faster radiation process of nested array implosion can be explained by analysing the corresponding result of the time-resolved one-dimensional imaging system, which demonstrates a better axial imploding uniformity and synchronization. In comparison with x-ray diode, the XRPM yields a higher height of x-ray power-platform due to its fiat energy response. The sub-peak after the main peak is proposed to be a result of the later-time additional implosion of plasma.     

含咪唑盐的三联吡啶铜配合物的合成和分子结构

通过带有不同长度的4-(4-氯烷氧基苯基)-2,2':6,2″-三联吡啶和N-甲基咪唑在甲苯中加热反应,制备了3种由烷氧基桥联的新型三联吡啶咪唑配体。研究了配体和过渡金属离子的配位反应。测定了三联吡啶咪唑铜配合物的单晶分子结构,在铜配合物中,Cu(Ⅱ)和两个三联吡啶单元形成扭曲八面体配位方式。Monoclinic,空间群P 21/c;a=1.7229(3) nm,b=1.5924(2) nm,c=2.1590(3) nm,α=90°,β=101.332(2)°,γ=90°,M_r=1298.09,V=5.8078(15) nm³,D_c=1.485 mg/m³,Z=4, F(000)=2684。     

脉冲微波辐射场空间分布的热声成像研究

微波热声成像技术具有非侵入式、高对比度、高分辨率和低成本等优点而日益受到重视, 基于以上特点该技术有望发展成为早期乳腺癌常规或者辅助筛查手段. 本文基于脉冲微波热声成像系统, 利用软件仿真和对装有饱和盐水的塑料管阵列进行三维热声成像, 对脉冲微波辐射场的空间分布进行了理论和实验研究, 其中: 塑料管阵列为直径3 mm, 间隔8 mm的9×9方形结构. 仿真和实验结果表明距离天线越远脉冲能量覆盖范围越大, 能被有效成像的塑料管数目越多; 塑料管阵列的热声成像结果为3.1 mm直径, 7.7 mm间距. 本文验证了微波热声成像技术对脉冲微波辐射场空间分布的成像能力, 对解决定量热声成像技术中微波场能量分布不均匀问题的研究具有重要意义.