胶体刻蚀技术简介及其应用探索

近年来,具有特殊功能的微观图案化表面引起了人们浓厚的研究兴趣,并被广泛应用于微反应器、生物传感器、微电子器件、光学器件以及生物界面等领域。在众多微观图案化表面的构筑方法中,胶体刻蚀技术备受人们关注。本文对胶体刻蚀技术的进展及其应用进行了综述,并对其发展趋势进行了展望。     

新型拉伸电磁矢量传感器的两维高精度波达方向估计

较之传统的共点电磁矢量传感器,拉伸电磁矢量传感器能够显著降低阵元间互耦,且非共点结构在硬件设计上更易于实现。但是现有拉伸电磁矢量传感器无法实现阵列的两维孔径扩展,导致了两维波达方向估计精度较差。针对此问题,提出一种新型的拉伸电磁矢量传感器。该阵列结构由单个拉伸电磁矢量传感器和单个电偶极子组成。利用单个拉伸电磁矢量传感器提供一维孔径扩展,再利用垂直于该拉伸电磁矢量传感器的单个电偶极子实现另一维的孔径扩展。针对该两维孔径扩展阵列,提出一种矢量叉积算法与相位干涉法相结合的算法来获取两维波达方向的高精度估计。所提阵列在降低互耦的同时,利用电磁矢量传感器提供的极化分集与两维孔径扩展带来的空间分集,使得两维波达方向估计精度大大提高。     

基于砂砾质辫状河沉积露头隔夹层研究

以准噶尔盆地西北缘扎伊尔山出露的三叠系克拉玛依组黑油山沟35 剖面为例,利用岩相组合和层次界面分析方法,结合沉积学理论,探讨了砂砾质辫状河岩石相组合、构型界面及构型单元级次,进而研究砂砾质辫状河河道砂体内部隔夹层的成因、级次、形态、规模及其控制下的渗流地质差异特征。结果表明,在研究区可以识别8 种典型岩相,8 个5 级储集体构型单元以及2 个3 级储集体构型单元。泥质隔夹层主要分为细粒沉积和泥砾型两种类型,泥砾型隔夹层主要发育在河道底部泥砾岩沉积,由河道侵蚀河岸或河底的泥岩快速堆积而成,主要分布在5 级或3 级界面之上,向河道两侧边缘减薄尖灭。同时,内部不同级次的泥质隔夹层控制了储层非均质。     

不同荧光蛋白基因标记利迪链霉菌

 利迪链霉菌（Streptomyces lydicus）A01 是一株分离自北京郊区对植物病原真菌具有广谱抑制作用的放线菌,在植物真菌病害防治中具有良好的应用前景。为了检测红霉素启动子在利迪链霉菌A01 中的活性,为后期对菌株A01 进行遗传改造提供技术支持,同时对生防菌A01 进行遗传标记以研究和阐明其在生态环境中的生物学行为规律,本实验采用两亲本接合的方法,将增强绿色荧光蛋白（EGFP）和红色荧光蛋白（RFP）基因片段克隆到携带红霉素启动子（ermE^*）的链霉菌表达载体pIB139 中,成功构建了以egfp 和rfp 为报告基因的重组载体pIB139-EGFP 和pIB139-RFP,并转化利迪链霉菌A01,突变株在荧光显微镜下观察到较强的绿色荧光和红色荧光,同时PCR 鉴定结果正确。这表明重组载体pIB139-EGFP 和pIB139-RFP 成功转入菌株A01,并且ermE^*启动子成功启动egfp 和rfp 基因表达。     

基于调度效益最大化的多功能组网认知雷达资源优化调度算法

在组网认知雷达中,针对多目标多任务(如搜索、跟踪与成像等)按优先级进行资源调度时易造成目标任务丢失的问题,提出基于调度效益最大化的多功能组网认知雷达资源优化调度算法。该算法将搜索与跟踪任务的时间窗考虑到目标函数中,通过目标任务的重要性(优先级)和有效性(时间窗)两个因素的加权来表示雷达对目标任务的调度效益,根据调度效益最大准则建立并利用遗传算法求解资源调度模型。对仿真结果分析表明,该方法能够提高组网认知雷达的整体效能。     

Single-negative properties of Ba2Co1.8Cu0.2Fe12O22 and Ba3Co2Fe23.4Zn0.6O41 hexagonal ferrites

The electromagnetic properties of Ba₂Co_1.8Cu_0.2Fe₁₂O₂₂ (Co₂Y) and Ba₃Co₂Fe_23.4Zn_0.6O₄₁ (Co₂Z) were studied by measuring microwave scattering parameters. In the transmission spectra of Ba₂Co_1.8Cu_0.2Fe₁₂O₂₂, a forbidden band emerges due to ferromagnetic resonance, and the permeability will turn to negative in the vicinity of the ferromagnetic resonance frequency. In the complex permittivity spectra of Ba₃Co₂Fe_23.4Zn_0.6O₄₁, the negative permittivity can be obtained due to dielectric resonance. Therefore, Co₂Y and Co₂Z can be used to construct left-handed materials possessing negative permeability and negative permittivity simultaneously.     

基于自组装胶体晶体构筑有序微结构

有关胶体晶体自组装以及以胶体晶体为模板制备有序图案化微结构方面的研究, 由于方法简便、结构多样、重复性好等优点, 近年来受到越来越多的关注. 本文系统总结了我们在胶体微球和胶体晶体领域开展的研究工作, 主要包括: 无机或聚合物胶体微球的设计制备、纳米复合及功能化; 结合聚合物材料可溶涨、可拉伸、热形变等特性构筑图案化胶体晶体、非球形对称胶体晶体、非紧密堆积胶体晶体等特殊结构; 以胶体晶体为模板制备三维大孔骨架、纳米环、纳米碗阵列等有序微结构等.     

钢筋混凝土框架结构地震失效模式的搜索与改善

为了改善钢筋混凝土框架结构的抗震性能,利用OpenSees软件建立了一个十层三跨的钢筋混凝土框架纤维模型.首先,对比分析了现浇楼板效应对结构抗震性能的影响.结果表明,现浇楼板的存在可增大柱的转动,减小梁的转动,削弱设计时强柱弱梁的效果,从而改变了梁与柱达到屈服状态和极限状态的先后顺序.然后,根据结构失效准则,利用Pushover方法搜索出结构地震失效模式.最后,采用3种不同的改善方案对结构进行重新设计,通过加强局部构件来改善结构地震失效模式.研究分析表明,改善结构的不同部位能提高结构的弹塑性刚度和延性,改变地震失效模式,提高抗震性能.结构地震失效模式的搜索与改善能有效揭示建筑结构地震弹塑性发展和破坏倒塌规律,为建立结构整体抗震能力分析理论提供依据.     

Growth potential of human hepatocarcinoma cells in the liver of neonatal immunocompetent mice and its relation to immunological tolerance

To determine the pathological behavior of human hepatocarcinoma cells in the liver microenvironment of neonatal non-immunode-ficient mice, three human hepatocarcinoma cell lines (Bel7402, HepG2, and SK-Hep-1), traced by DiI, were transplanted into the intrahepatic or subcutaneous tissue of neonatal and adult Kunming mice. Histopathological observations showed that cells in the adult liver induced a severe immune response as early as the second day after the implantation, while the subcutaneous neoplasm underwent extensive necrosis by the end of the study. Only the cells injected into the neonatal liver underwent a delayed immunologic rejection in the organ microenvironment. These cells retained recognizable tumor features over the first seven days, and displayed an intrahepatic invasive pattern. The expression of tumor markers including alpha-fetoprotein and survivin was maintained. The quantitative ELISA for the expression patterns of IL-2 and IL-10 also confirmed that the intrahepatic immunity was non-susceptive during this period. The high serum alpha-fetoprotein level was inversely correlated with the change in immune response. Our study provided a bio-system for the research of immune responses to xenografts in the liver.     

Detection of dynamic brain networks modulated by acupuncture using a graph theory model

Neuroimaging studies involving acute acupuncture manipulation have already demonstrated significant modulatory effects on wide limbic/paralimbic nuclei, subcortical gray structures and the neocortical system of the brain. Due to the sustained effect of acupuncture, however, knowledge on the organization of such large-scale cortical networks behind the active needle stimulation phase is lacking. In this study, we originally adopted a network model analysis from graph theory to evaluate the functional connectivity among multiple brain regions during the post-stimulus phase. Evidence from our findings clearly supported the existence of a large organized functional connectivity network related to acupuncture function in the resting brain. More importantly, acupuncture can change such a network into a functional state underlying both pain perception and modulation, which is exhibited by significant changes in the functional connectivity of some brain regions. This analysis may help us to better understand the long-lasting effects of acupuncture on brain function, as well as the potential benefits of clinical treatments.