Polycapillary X-ray lens for the secondary focusing Beijing synchrotron radiation source

According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station, theoretical modeling of the Beijing synchrotron radiation source is developed for capillary optics. Using this theoretical modeling, the influences of the configuration curve of the polycapillary X-ray lens on transmission efficiency and working distance are analyzed. The experimental results of the transmission efficiency and working distance at the biological macromolecule station are in good agreement with the theoretical results.

Hard X-ray focusing resolution and efficiency test with a thickness correction multilayer Laue lens

The multilayer Laue lens(MLL) is a diffractive focusing optical element which can focus hard X-rays down to the nanometer scale. In this study, a WSi_(2)/Si multilayer structure consisting of 1736 layers, with a 7.2-nm-thick outermost layer and a total thickness of 17 μm, is prepared by DC magnetron sputtering. Regarding the thin film growth rate calibration, we correct the long-term growth rate drift from 2 to 0.6%, as measured by the grazing incidence X-ray reflectivity(GIXRR). A one-dimensional line focusing resolution of 64 nm was achieved,while the diffraction efficiency was 38% of the-1 order of the MLL Shanghai Synchrotron Radiation Facility(SSRF) with the BL15U beamline.

X-ray focusing using an x-ray lens composed of multi-square polycapillary slices

A new type of x-ray lens composed of multi-square polycapillary slices(ASPXRL)used in focusing parallel x-ray beam was presented in this paper.Compared with conventional x-ray polycapillary lens,ASPXRL can provide smaller and brighter focus.The effects of the manufacturing imperfections on focusing quality of ASPXRL were evaluated with the values of transmission efficiency and discussed.It is suggested that ASPXRL has application prospects as a condenser lens for x-ray microscopy and flux collectors for x-ray analytical instruments.

Focusing high-energy x-rays by a P MMA compound x-ray lens on Beijing synchrotron radiation facility

The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors＇ recent research on a polymethyl methacrylate （PMMA） compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.

融合多策略改进的黏菌优化算法

针对黏菌优化算法(Slime Mould Algorithm,SMA)的寻优过程存在收敛效率较低、容易陷入局部最优解等问题,文中提出融合多策略改进的黏菌优化算法(Improved SMA Fused with Multi-strategy,MISMA).引入Halton序列,丰富初始种群的多样性,提升算法寻优的遍历性和收敛精度.融入差分变异思想,改进算法的全局位置更新公式,强化全局探索能力,增强算法的持续寻优性能.糅合改进收敛因子和精英选择机制的局部搜索策略,提升算法的局部开采能力,更好地平衡算法的全局探索与局部开发进程.基于动态边界的透镜成像学习策略改善个体的质量,加强算法反早熟及摆脱局部最优解的能力.在13个基准函数及部分CEC2014测试函数上的数值仿真实验表明,MISMA具有较强的鲁棒性.此外,在光伏电池组件模型参数优化实验上进一步验证MISMA在处理实际工程优化问题时的优越性及适用性.

X-ray nanometer focusing at the SSRF based on a multilayer Laue lens

We designed and fabricated a multilayer Laue lens （MLL） as a hard X-ray focusing device. WSi2/Si multilayers were chosen owing to their excellent optical properties and relatively sharp interface. The multilayer sample was fabricated by using direct current （DC） magnetron sputtering technology and then was sliced and thinned to form an MLL. The thickness of each layer was determined by scanning electron microscopy （SEM） image analysis with marking layers. The focusing property of the MLL was measured at Beamline 15U, Shanghai Synchrotron Facility （SSRF）. One-dimensional （1D） focusing resolutions of 92 nm are obtained at photon energy of 14 keV.

Hard X-ray one dimensional nano-focusing at the SSRF using a WSi_2 /Si multilayer Laue lens

The multilayer Laue lens （MLL） is a novel diffraction optics which can realize nanometer focusing of hard X-rays with high efficiency. In this paper, a 7.9 μm-thick MLL with the outmost layer thickness of 15 nm is designed based on dynamical diffraction theory. The MLL is fabricated by first depositing the depth-graded multilayer using direct current （DC） magnetron sputtering technology. Then, the multilayer sample is sliced, and both cross-sections are thinned and polished to a depth of 35–41 μm. The focusing property of the MLL is measured at the Shanghai Synchrotron Facility （SSRF）. One-dimensional （1D） focusing resolutions of 205 nm and 221 nm are obtained at E=14 keV and 18 keV, respectively. It demonstrates that the fabricated MLL can focus hard X-rays into nanometer scale.

Design and fabrication of one-dimensional focusing X-ray compound lens with A1 material

A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced, the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach. A kind of technique named moulding is developed for fabricating the one-dimensional (1D) compound X-ray lens with Al material and the fabrication process is presented. In addition, a two-time coating method is used to improve the numerical apertures of the compound lenses. Furthermore, the focusing performance of the Al compound X-ray lens under the high energy X-rays is measured.

Bifocal-Lens Converging Based OAM Wireless Communications

Orbital angular momentum(OAM)based radio vortex wireless communications have received much attention recently because it can significantly increase the spectrum efficiency.The uniform circular array(UCA)is a simple antenna structure for high spectrum efficiency radio vortex wireless communications.How-ever,the OAM based electromagnetic waves are vortically hollow and divergent,which may result in the signal loss.Moreover,the divergence of corresponding OAM based electromagnetic wave increases as the order of OAM-mode increases.Therefore,it is difficult to use high-order OAM-mode,because the corresponding received signal-to-noise ratio(SNR)is very small.To overcome the difficulty of high-order OAM modes transmission,in this paper we propose a lens antenna based electromagnetic waves converging scheme,which maintains the angular identification of multiple OAM-modes for radio vortex wireless communications.We further develop a bifocal lens antenna to not only converge the electromagnetic wave,but also compensate the SNR loss on traditional electromagnetic waves.Simulation results show that the proposed bifocal lens can converge the OAM waves into cylinder-like beams,providing an efficient way to in-crease the spectrum efficiency of wireless communications.

两种矫正方式对近视患者AC/A的对比研究

目的:研究青少年近视患者在配戴角膜塑形镜与配戴框架眼镜后各自AC/A的变化情况,并进行对比分析,进一步明确角膜塑形镜与框架眼镜对近视患者视功能的影响,及对青少年近视的控制作用。方法:随机选取60例来我院成功验配角膜塑形镜的青少年近视患者作为试验组,随机选取60例门诊就诊并给予框架眼镜的青少年近视患者作为对照组,观察两组患者屈光矫正前后AC/A及等效球镜度的变化并进行对比研究。随访时间依次为戴镜1,3,6mo;1a。结果:试验组戴镜前和后1,3,6mo;1a的AC/A值分别为4.05±2.03,3.05±1.85,3.31±1.02,3.14±1.64,3.20±1.55,戴镜后1,3,6mo;1a与戴镜前比较,差异均有统计学意义(P<0.05)。对照组戴镜前和后1,3,6mo;1a分别为4.12±1.86,4.09±1.38,3.58±1.45,3.84±1.41,4.23±2.01,戴镜后1,6mo;1a与戴镜前比较,差异无统计学意义(P>0.05),戴镜后3mo与戴镜前比较,有显著差异(P<0.05)。两组戴镜前无显著差异(P>0.05);戴镜后1,6mo;1a,两组有显著差异(P<0.05);戴镜后3mo两组差异无统计学意义(P>0.05)。近视度数增长的观察时间为1a。试验组等效球镜度增加了0.38±0.35DS,对照组增加了0.84±0.56DS,两组差异有统计学意义(P<0.05)。结论:两种矫正方式都能降低高AC/A值,试验组较对照组能更快更好地改善调节与集合的关系,近视度数增长后AC/A值会偏高。角膜塑形镜对中低度近视的矫正有效,它较框架眼镜能更有效地控制青少年近视的增长速度,是目前控制近视的一种有效方法。它对近视患者视功能的改善机制还有待进一步的研究。

微束微区X荧光探针分析仪在矿石微粒分析中的应用

描述了一种微束微区X荧光探针分析仪,它采用会聚X光透镜来聚焦入射X射线,可对样品内微小面积的元素及其含量进行分析。以铁矿石内颗粒的测量为例,表明了微束微区X荧光探针分析仪是区分矿石中微小颗粒的有力工具,在细微材料成分分析和无损检测中具有广阔的前景。

相关参数对长距离近似无衍射光束质量的影响

利用光线追迹法分析了会聚透镜焦距及会聚透镜与轴棱锥的距离等相关参数对双轴棱锥产生的长距离近似无衍射光束传播距离的影响,运用Mathcad对其进行了数值模拟。结果显示:在其他条件不变的情况下,近似无衍射光束的传播距离随会聚透镜焦距的增大而减小,随会聚透镜与轴棱锥之间距离的增大而增大。通过实验对理论进行了验证,所得结果与理论分析相吻合。

CO_2 激光加工机连续可变焦距光学系统

研究了一种长工作距离（１２１ｍｍ）、短焦距、在１９～５７ｍｍ范围内连续可变焦距的ＣＯ２激光加工机新型光学聚焦系统，论述了系统的特点及基本原理，给出了有关设计参数．

全景成像技术的现状和进展

全景成像技术在机器人、计算机视觉和虚拟现实领域有着重要的应用。旋转拼接,鱼眼透镜和折反射透镜是实现全景成像技术的主要方法。其中旋转拼接和鱼眼透镜是符合人眼视觉的中心投影法原理,折反射全景成像则是属于环带成像,即柱面映射投影。分析了以上全景成像系统的优缺点,建立了折反射全景成像系统的数学模型。结果表明,折反射系统由于集成化和小型化的特点将会得到更为广泛的应用。

浅谈《调节机制新概念：基于超焦距-微变焦的人眼光学系统》

调节是指人眼在看清近处物体时晶状体屈光能力发生改变的现象。《调节机制新概念：基于超焦距一微变焦的人眼光学系统》一文引入了摄影镜头的超焦距概念，并基于超焦距的特点，提出人眼实际上存在3个超焦距，即远超焦距、近超焦距和调节超焦距。在调节活动中，睫状肌的收缩是推压悬韧带、悬韧带推压晶状体赤道部，还是使拉紧的悬韧带松弛、晶状体前突，这对于理解《调节机制新概念：基于超焦距一微变焦的人眼光学系统》是至关重要的。从解剖结构上来讲，在调节活动中，睫状肌的收缩推压悬韧带、纤弱的悬韧带推压晶状体赤道部的可能性较小，而使拉紧的悬韧带松弛、晶状体前突的可能性更大。笔者认为，睫状肌的收缩在调节活动中具有主动性的启动作用，因此当眼从视近转向视远时，睫状肌（收缩的环形肌）将会迅即恢复到松弛常态，晶状体受悬韧带的牵拉而恢复到原来的相对扁平状，并非被动性压迫，因为晶状体并不是调节活动的启动体，只不过是一个承载体而已。人眼的调节活动是非常复杂的，在整个调节活动中，不仅有睫状肌的收缩、晶状体屈光能力的增加，也伴随着瞳孔的缩小和集合的发生，因此任何机械、单一的模式都很难解释人眼复杂的调节活动。

薄透镜在不同介质中的会聚与发散性质

从薄透镜的焦距公式出发,讨论了各种透镜在不同介质中的会聚与发散性质.透镜的会聚、发散性质既与透镜的形状和折射率有关,又与透镜两侧介质的折射率有关.

彩色显像管中主聚焦透镜的研究

在COTY系统中,采用XL透镜来改善会聚性能,减小会聚/聚焦之间的矛盾。XL透镜可以在不损失聚焦性能的前提下缩小束间距提高会聚特性。但是在XL透镜中边束像差比中束大得多,为了进一步降低像差,本文提出在XL电子枪中采用OLF透镜来扩大透镜的孔径,改善分辨率。本文给出了三维计算机程序,对主聚焦透镜进行三维计算,得到了球差系数和其它光学参量。这些数据证实了在新的方案中球差确实被降低,而且会聚特性也得以改善。

会聚光中的傅立叶变换透镜用于彩虹全息

在提高激光能量利用率和增大成像面积前提下 ,为了尽量减小透镜口径 ,采用会聚光照明前傅立叶变换透镜。由于它在全息制版镜头对称面上形成实的频谱面 ,从而可进行空间滤波处理。结果 ,透镜口径由平行光照明时的 13 5mm减小到 98mm ,成像面直径达到 10 0mm ,曝光时间可缩短为原来的 1/5。由此可得出 ,会聚光照明的傅立叶变换光路 ,在减小透镜口径方面优于 4f系统。

偏光显微镜聚敛光系统光路分析

通过实验和计算，文章证明了勃氏镜进入显微光路后，可使整个显微镜系统变成望远系统。望远系统接收平行光信号，形成干涉图或偏光图像；而显微系统接收非平行光信号形成矿物像。文章不仅对偏光图和干涉图在显微镜筒中的光路变化及成像机理进行了深入讨论，并且对如何保持干涉图和偏光图像清晰提出了调试意见。

多策略增强花授粉算法及其应用

针对经典花授粉算法容易陷入局部最优解和收敛速度慢的缺点,提出一种增强型透镜成像策略和随机邻域变异策略的花授粉算法。通过增强型透镜成像策略扩展花授粉算法的搜索空间,增加解的多样性,有助于算法跳出局部最优解。引入随机邻域变异策略,借助邻域内的信息指导算法搜索,增强算法的收敛精度和搜索速度。对改进后的花授粉算法和四种其他改进算法在CEC2013测试函数上进行比较,实验证明改进后的多策略花授粉算法不论是收敛精度还是搜索速度都比对比算法优秀。最后把多策略花授粉算法应用在汽车传动参数模型上研究该算法的实际效用,结果表明多策略花授粉算法在汽车传动参数优化问题上都优于对比算法。