表面活性剂辅助二氧化硅纳米颗粒在非水基液中的分散研究（英文）

研究了粒径10~100nm的二氧化硅纳米颗粒在非水基液中的表面活性剂辅助分散。结合颗粒表面特定官能团结构,针对性选择了合适的表面活性剂,氢键桥梁作用和长链分子空间位阻作用抑制了颗粒团聚行为。当表面活性剂体积分数6%的时候,动态光散射测试结果表明颗粒中位尺度30.2nm,与透射电镜测试结果吻合,展现了良好的分散性。     

Micromechanism of sulfurizing activated carbon and its ability to adsorb mercury

The effect of ambient environment (dry or wet) and overlapping laser pulses on the laser ablation performance of brass has been investigated. For this purpose, a Q-switched, frequency doubled Nd:YAG laser with a wavelength of 532 nm, pulse energy of 150 mJ, pulse width of 6 ns and repetition rate of 10 Hz is employed. In order to explore the effect of ambient environments, brass targets have been exposed in deionized water, methanol and air. The targets are exposed for 1000, 2000, 3000 and 4000 succeeding pulses in each atmosphere. The surface morphology and chemical composition of ablated targets have been characterized by using Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM) and Attenuated Total Reflection (ATR) techniques. In case of liquid environment, various features like nano- and micro-scale laser-induced periodic surface structures with periodicity 500 nm–1 μm, cavities of size few micrometers with multiple ablative layers and phenomenon of thermal stress cracking are observed. These features are originated by various chemical and thermal phenomena induced by laser heating at the liquid–solid interfaces. The convective bubble motion, explosive boiling, pressure gradients, cluster and colloid formation due to confinement effects of liquids are possible cause for such kind of features. The metal oxides and alcohol formed on irradiated surface are also playing the significant role for the formation of these kinds of structure. In case of air one huge crater is formed along with the redeposition of sputtered material and is ascribed to laser-induced evaporation and oxide formation.     

对乙酰基偶氮氯膦光度法测定烟草中钙的方法研究

研究了对乙酰基偶氮氯膦 ( ACCPP)与钙的显色反应 ,在 p H=8.5的氯化铵 -氨水缓冲介质中 ,乳化剂 - OP存在下 ,ACCPP与钙反应生成 1∶ 1稳定络合物 ,λmax=680 nm,ε=4 .0 1× 10 4 L· mol-1· cm-1。钙含量在 0— 2 0μg/2 5m L范围内符合比耳定律 ,方法用于烟草样品中钙含量的测定 ,结果令人满意。     

混合纤芯光子晶体光纤超平坦色散的研究

利用平面波展开法,系统地研究了一种具有混合纤芯结构的光子晶体光纤的色散特性. 数值计算结果表明,通过优化结构参量,这种新型结构的光子晶体光纤在通信窗口1.55 μm 附近可以获得带宽超过800 nm的超平坦色散区域（色散曲线的变化范围不超过 ±0.6 ps·km－1·nm－1）.     

近红外光谱监测体外循环手术中脑组织氧合状况的研究

体外循环手术中,为防止因脑氧供需失衡导致脑缺氧,就要实时监测患者局部脑组织的氧合状况,以根据其变化调整生理参数或采取应急手段。用该研究小组自行研制的近红外仪器(使用一个双波长的近红外光源和两个近红外检测器)监测心脏手术中患者的脑氧,可以求出局部脑组织血红蛋白浓度的变化,并根据稳态空间分辨光谱(SRS)算法求出局部脑组织的氧饱和度(rSO₂)。体外循环中用监护仪监测患者的混合静脉血氧饱和度(SvO₂)等生理参数。测得的血红蛋白浓度变化容易受到干扰,而rSO₂的抗干扰性能较好。rSO₂在整个手术过程中都可以监测到,而SvO₂只能在体外循环过程中监测到。多数患者rSO₂和SvO₂存在正向相关性,但二者的相关系数并不很高。这是因为SvO₂是大静脉的血氧饱和度,而测得的rSO₂反映局部脑组织的氧合状况,二者的生理意义不同。实验结果表明,体外循环手术中rSO₂可以反映患者脑组织氧合状况的变化,而仅仅监测SvO₂是不够的。     

金属柱平板慢波系统高频特性研究

对于离散的金属柱结构构建的周期性平板慢波系统,本文利用3维FDTD方法结合HFSS仿真软件深入分析了该慢波系统的高频特性.研究了金属柱高度、周期长度对色散特性的影响,计算了耦合阻抗,并与传统光栅慢波系统特性进行了对比分析.分析表明金属柱慢波系统既有与传统光栅慢波系统相似的高频特性,又具有独自的特点,位于离散的金属柱周期间隙中的电子注互作用耦合阻抗具有对称性;金属柱结构用作真空电子器件的高频系统可增加发生有效互作用的电子注厚度,降低起振电流密度,提高器件效率.本文的分析结果为设计低电流密度工作的多电子注短毫 关键词： 金属柱平板慢波系统 3维FDTD算法 色散特性 耦合阻抗     

基于斯托克斯矢量的偏振成像仪器及其进展

偏振成像技术将景物的偏振信息转化为二维图像信息,从而可以和灰度图像一样对目标景物进行场景特征分析。介绍了基于斯托克斯矢量的偏振成像原理。按照获取斯托克斯矢量方法的不同,分别介绍了偏振片起偏、偏振棱镜分光和可变延迟波片调制三类分时偏振成像方式,分振幅、分孔径、分焦平面三种同时偏振成像方式。结合我国的制造水平,设计了双CCD渥拉斯顿棱镜同时偏振成像实验系统,并采集了实验图像。分析了各种偏振成像方式的优缺点。指出了偏振激光照明主动偏振成像、光谱偏振成像是偏振成像仪器进一步的发展方向。     

The Quantum Search Algorithms for All Solutions

Two quantum search algorithms are proposed for known and unknown number of solutions. The first algorithm begins with an arbitrary rotation phase Grover search algorithm by recursive equations, then a sub-algorithm (G _α algorithm) and the corresponding quantum circuits are designed, the probability of success and expected number of iterations of the sub-algorithm to find a solution are analyzed. Based on these results, we design the whole algorithm and estimate the expected number of iterations to search all solutions. The design of the second algorithm follows the same steps. We firstly study a quantum counting algorithm, then design a sub-algorithm (QCG algorithm), and analyze the probability of success and the expected number of iterations to find a solution. Finally the whole algorithm for all solutions is designed and analyzed. The analysis results show that these two algorithms find all solutions in the expected times of $O(t\sqrt{N})$ (t is a number of solutions and N is a total of states).     

色散补偿光子晶体光纤结构参数对其色散的影响

光子晶体光纤由于其灵活可调的色散特性用作色散补偿具有极大的应用潜力. 设计了一种色散补偿光子晶体光纤, 并运用频域有限差分法模拟了其色散特性,从理论上分析了其结构参数孔间距Λ和空气占空比d/Λ对该光子晶体光纤的色散系数的影响, 并且实际制备出了3种不同结构参数的光子晶体光纤. 通过对其色散曲线对比分析表明: 当光子晶体光纤孔间距在1 μm附近时, 其色散系数随着孔间距Λ和占空比d/Λ的增大而增加, 但对于孔间距Λ的变化比占空比d/Λ更为敏感, 并且随着孔间距Λ的增加,其对色散系数的影响能力逐渐减小. 设计并制备的光子晶体光纤在1550 nm处的色散系数为-241.5 ps·nm^-1·km^-1, 相对色散斜率为0.0018, 具有较好的色散补偿能力. 关键词： 色散 色散补偿 光子晶体光纤 结构参数     

Interplay between superconductivity and pseudogap state in bilayer cuprate superconductors

The interplay between the superconducting gap and normal-state pseudogap in the bilayer cuprate superconductors is studied based on the kinetic energy driven superconducting mechanism. It is shown that the charge carrier interaction directly from the interlayer coherent hopping in the kinetic energy by exchanging spin excitations does not provide the contribution to the normal-state pseudogap in the particle–hole channel and superconducting gap in the particle–particle channel, while only the charge carrier interaction directly from the intralayer hopping in the kinetic energy by exchanging spin excitations induces the normal-state pseudogap in the particle–hole channel and superconducting gap in the particle–particle channel, and then the two-gap behavior is a universal feature for the single layer and bilayer cuprate superconductors.