PZT／Terfenol-D／PVDF层状复合磁电材料谐振特性

采用热压法制备出二层锆钛酸铅(PZT)／聚偏氟乙烯(PVDF)与1层Tb0.28Dy0.72Fe2(Terfenol-D)／PVDF叠层结构的三元复合磁电材料，研究了不同PVDF含量，以及不同层厚比tp／L对样品的介电常数、介电损耗、电阻率、谐振频率以及磁电转换系数αE33，αE31的影响规律，结果显示PVDF的含量和层厚比都存在最佳值(最佳值出现在产0．5，tp／L=2／7)，并且在这个最佳值处，磁电转换系数达到最大。     

Detection of water ingress in composite sandwich structures: a magnetic resonance approach

Water ingress inside honeycomb sandwich panels during service has been linked to in-flight failure in some aircraft. There is an ongoing effort to develop nondestructive testing methods to detect the presence of water within the panels. Magnetic resonance (MR) represents an attractive approach in that it is sensitive to moisture. Using a unilateral MR sensor, testing can be applied directly to the surface of the panel. The viability of MR is demonstrated through laboratory imaging of both water within sandwich panels, as well as the adhesive itself. The detection of water using a one-sided handheld MR sensor is presented. It is shown that simple detection, as well as spatial localization of water within sandwich panels is possible.     

丁基罗丹明B-AuI4-缔合纳米粒子体系的极谱猝灭效应研究

在0．1mol／LH2SO4介质中，丁基罗丹明B(RBB)在-0．59伏产生1个单扫描极谱峰。当有AuI^-4存在时，AuI^-4与RBB^ 主要通过静电引力形成疏水性的AuI4—2RBB缔合物分子。AuI4—2RBB存在较强的分子间作用力和疏水作用力而生成紫红色的(AuI4—RBB)n纳米微粒，在470nm处产生1个瑞利散射峰，在610nm处产生1个共振瑞利散射峰；而在-0．59伏处的极谱峰降低。这是由于该紫红色复合纳米微粒形成所致。当纳米微粒体系加入乙醇后，体系的瑞利散射峰和共振瑞利散射峰消失，极谱峰、同步荧光峰和颜色恢复，由于乙醇而致使紫红色的(AuI4-RBB)n纳米微粒分解为红色AuI4—RBB分子。研究结果表明，紫红色(AuI4-RBB)。纳米粒子的形成是其极谱猝灭和共振瑞利散射效应的根本原因。     

用弯曲模型推导二组元复合材料杨氏模量新公式

用弯曲模型推导了适用于悬丝耦合弯曲共振法检测金属第二组元的杨氏模量的理论公式。通过实验数据计算。结果表明在两组元h2/h1≈1时与文献[2]的计算结果几乎接近，为用悬丝耦合弯曲共振法检测各种减振材料，陶瓷材料杨氏模量提供了理论公式；同时用改进后的弯曲模型推导出了适用于纤维复合材料横向杨氏模量的预测公式。     

几种血卟啉3,8—烷氧（硫）基衍生物产生单重态氧能力的研究

在“血卟啉衍生物”(HPD)肿瘤光动力疗法取得令人瞩目成就的同时,化学家们证明了临床使用的HPD制剂并非原意义上的血卟啉衍生物,而是一种复杂的卟啉混合物,其中血卟啉(HP),羟乙基-乙烯基-次卟啉(HVD),原卟啉(PP)约占总量的80％,Dougherty等分离得到其余20％未知结构羧基卟啉,认为此为HPD的有效成分,经进一步分析测定其主要成分是二血卟啉醚(DHE)。但最近的工作又表明,全合成得到的DHE与HPD有效成分的化学组成及生物活性亦不相同。显然这类药物组分复杂、结构的不确定限制了肿瘤光动力疗法的进一步发展。近年来,人们正试图从已知结构的化合物中探索新的光敏药物,作者在合成出一系列结构确定的单一组分血卟啉     

High resolution solid state 13C n.m.r. of butadiene grafted polypropylene

¹H dipolar decoupled ¹³C n.m.r. experiments with the aid of the magic angle spinning technique have been used to determine the graft content and the isomer content of the polybutadiene grafts in a graft copolymer with isotactic polypropylene.     

雅砻江楞古水电站场址区宋玉断层活动性研究

楞古水电站位于区域构造复杂的雅砻江中游, 场址周边断裂构造较发育, 场址区内发育有较大的宋玉断层, 研 究其活动性对枢纽建筑布置和工程抗震设防措施均具有重要意义。在遥感解译的基础上, 通过野外验证和追踪调 查, 结合断层构造岩石英形貌扫描、 电子自旋共振(ESR) 测龄和近代地震震中分析, 确定了宋玉断裂的活动年代, 得 出了宋玉断层不属于工程活动断层的结论。     

Augment low-field intra-operative MRI with preoperative MRI using a hybrid non-rigid registration method

Background

Preoperatively acquired diffusion tensor image (DTI) and blood oxygen level dependent (BOLD) have been proved to be effective in providing more anatomical and functional information; however, the brain deformation induced by brain shift and tumor resection severely impairs the correspondence between the image space and the patient space in image-guided neurosurgery.

Method

To address the brain deformation, we developed a hybrid non-rigid registration method to register high-field preoperative MRI with low-field intra-operative MRI in order to recover the deformation induced by brain shift and tumor resection. The registered DTI and BOLD are fused with low-field intra-operative MRI for image-guided neurosurgery.

Results

The proposed hybrid registration method was evaluated by comparing the landmarks predicted by the hybrid registration method with the landmarks identified in the low-field intra-operative MRI for 10 patients. The prediction error of the hybrid method is 1.92 ± 0.54 mm, and the compensation accuracy is 74.3 ± 5.0%. Compared to the landmarks far from the resection region, those near the resection region demonstrated a higher compensation accuracy (P-value = .003) although these landmarks had larger initial displacements.

Conclusions

The proposed hybrid registration method is able to bring preoperatively acquired BOLD and DTI into the operating room and compensate for the deformation to augment low-field intra-operative MRI with rich anatomical and functional information.     

(Ag)_核·(Au)_壳复合纳米粒子的制备

以银原子团簇作晶种,采用微波高压液相合成法制备了分散性好、规则球形的(Ag)核·(Au)壳复合纳米粒子。研究了(Ag)核·(Au)壳复合纳米粒子的紫外可见吸收光谱和共振散射光谱特性。结果表明,液相(Ag)核·(Au)壳复合纳米粒子和高压微波合成的液相金纳米粒子的最强共振散射峰均在580nm处,它们的吸收光谱图相似,最大吸收分别在518.5nm和524.8nm。     

基于复合左右手传输线结构的新型微带天线

基于复合左右手传输线结构的零阶谐振理论,提出了一种新型双层结构的微带天线,仿真结果表明该天线具有比单层微带天线更小的尺寸。研究了天线各结构参数对天线特性的影响,并对各参数进行了优化仿真。仿真结果表明该天线具有全向辐射特性,与传统微带天线相比,该天线具有体积小的特点。