Optical System for Asymmetrical Crossed Czerny-Turner Raman Spectrometer with High Luminous Flux

为克服分立式便携拉曼光谱仪光通量低的缺点,设计了一种集拉曼探头光路与分光系统于一体的光学系统。探头光路采用大数值孔径的非球面透镜实现样品的有效激发和信号的高效收集,通过胶合透镜组缩小会聚光路尺寸、消除轴向色差。分光系统基于交叉非对称Czerny-Turner结构,为获得期望的光谱分辨率和光谱范围,建立了分光系统光谱分辨率及光谱范围与交叉非对称Czerny-Turner结构参数的关系。由测得的汞灯谱图可知,分光系统的光谱分辨率优于6 cm~(-1)(0.37 nm),光谱范围为790~950 nm(200~2000 cm~(-1))。将设计的光学系统对CCL4进行测试,实验结果表明在相同积分时间内由这种整体式的光学系统检测到的CCL4光谱谱峰强度是用商业探头通过光纤连接分光系统检测到的近3倍,验证了光学系统设计的合理性。To overcome the low luminous flux in separated portable Raman spectrometer, an optical system embodies the probe of Raman spectrometer and monochromator is designed. An aspherical lens with high numerical aperture is used to obtain the effective excitation of sample and the efficient collection of signal in the optical system of the probe. A cemented lens group is used to minish the size of converging path and eliminate chromatic aberration.The monochromator is based on asymmetrical crossed Czerny-Turner structure. For the purpose of achieving desired spectrum resolution and spectrum range, the relationship between the spectrum resolution and spectrum range of the monochromator and the structural parameters of the asymmetrical crossed Czerny-Turner system is established. According to the tested spectrogram of mercury lamp, the spectrum resolution of the monochromator is better than 6 cm~(-1)(0.37 nm), and spectrum range is 790~950 nm(200~2000 cm~(-1)). A sample of CCL4 is introduced to examine the performance of the optical system, the experimented results demonstrate that the peak intensity of spectrogram of CCL4 measured by this incorporative optical system is almost three times as high as that using a commercial probe couples to the monochromator, which verifies the rationality of the design of the optical system.国家自然科学基金(21503171);; 中央高校基本科研业务费项目(20720150091、20720150094);; 福建省高端装备制造协同创新中心资

A Survey of Swarm Intelligence

群体智能利用群体的优势,在没有集中控制、不提供全局模型的前提下,为寻找复杂问题的解决方案提供了新的思路。首先阐述了群体智能的研究现状,包括典型的蚂蚁群优化算法、粒子群优化算法、群体机器人以及算法的应用。在此基础上,对今后的研究趋势进行了分析和展望:对群体智能系统底层机制的研究以及群体机器人的研究将是今后研究的重点,具有重大意义和广阔前景

A new algorithm for TSP based on swarm intelligence

Inspired by the behavior of people, a new algorithm for the combinatorial optimization is proposed. This is a heuristic approach based on swarm intelligence, which is firstly introduced as the theoretical background in this paper. It is also a parallel algorithm, in which individuals of the swarm search the state space independently and simultaneously. When one encounters another in the process, they would communicate with each other, and utilize the more valuable experiences to improve their own fitness. A positive feedback mechanism is designed to avoid vibrations. Ten benchmarks of the TSPLIB are tested in the experiments. The results indicate that the algorithm can quickly converge to the optimal solution with quite low cost. Some conclusions about the algorithm are summarized finally

A swarm-based learning method inspired by social insects

Inspired by cooperative transport behaviors of ants, on the basis of Q-learning, a new learning method, Neighbor-Information-Reference (NIR) learning method, is present in the paper. This is a swarm-based learning method, in which principles of swarm intelligence are strictly complied with. In NIR learning, the i-interval neighbor's information, namely its discounted reward, is referenced when an individual selects the next state, so that it can make the best decision in a computable local neighborhood. In application, different policies of NIR learning are recommended by controlling the parameters according to time-relativity of concrete tasks. NIR learning can remarkably improve individual efficiency, and make swarm more "intelligent"

基于B样条的TERS形貌成像背景扣除方法

在针尖增强拉曼光谱(TERS)形貌成像过程中,由于针尖与扫描台无法绝对平行、样品电子密度骤变处针尖快速升降以及扫描控制系统响应时间特性差等综合原因的影响,往往使形貌图中带有倾斜或边界面卷曲的成像背景。成像背景对样品形貌的识别和分析带来十分不利的影响,而背景扣除就是解决该问题的重要手段,也是形貌成像预处理的重要组成部分。背景扣除的原理一般是通过拟合背景的方法来扣除成像中的背景。传统的背景扣除方法是利用多项式拟合的方法对成像进行逐行的基线校正,但是该方法在处理形貌成像时常常会由于过拟合而造成样品形貌的失真,同时容易在图片上留下明显的线条纹理。针对传统方法的缺点,本文提出采用B样条曲面拟合方法,直接对样品形貌图进行曲面背景拟合,发挥B样条低阶光滑的优点,能够有效克服传统方法的缺陷。在实验中,同时利用传统方法和该方法对金单晶和合成金片的形貌图进行背景扣除,实验结果表明,两种方法都能够扣除样品形貌图中的成像背景,但与传统方法相比,所提出的方法不会造成样品形貌的失真,且不会留下线条纹理,获得了更加良好的背景扣除效果,为进一步分析样品形貌特征提供了更准确可靠的信息,是一种更加有效的TERS形貌成像背景扣除算法。福建省高端装备制造协同创新中心项目;;国家自然科学基金项目(21503171)资

The Performance Investigation on Nano Carbon-Modified Lithium Hydroxide for Low-temperature Chemical Heat Storage

LiOH·H_2O nanoparticles supported on grapheneoxide（GO） and carboxylic multi wallcarbon nano tubes（c-MWCNTs） were facilely synthesized by a hydrothermal process.The pivotal thermophysical property of nanocomposites was characterized by scanning elect

纳米碳/氢氧化锂复合材料的低温化学蓄热性能研究

本文将氧化石墨烯（GO）、羧基化多壁碳纳米管（c-MWCNTs）等纳米碳材料通过水热的方法与氢氧化锂进行反应,得到碳基氢氧化锂化学蓄热复合材料。采用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射分析仪（XRD）以及热重/同步差热分析仪（TGA-DSC）等表征手段获取了复合材料的表观形貌、负载组分、蓄热密度等关键热物性参数。研究表明纳米碳材料的复合使LiOH的单体水合速率大幅度提升,与此同时蓄热密度有着不同程度地增大,其中以GO/LiOH复合材料的化学蓄放热性能最为突出。除此之外,材料整体的导热系数也由于GO的复合有着显著的提高。本研究拓展了碳材料在储能领域的应用范围,针对纳米碳化学蓄热复合材料提供了理性的设计方法

Route-exchange algorithm for combinatorial optimization based on swarm intelligence

Inspired by the information interaction of individuals in swarm intelligence, a new algorithm for combinatorial optimization is proposed, which is called as Route-Exchange Algorithm (REA). This is a heuristic approach, in which the individuals of the swarm search the state space independently and simultaneously. When one encounters another in the process, they would interact with each other, exchange the information of routes toured, and utilize the more valuable experiences to improve their own search efficiency. An elite strategy is designed to avoid vibrations. The algorithm has been applied to Traveling Salesman Problem (TSP) and assignment problem in this paper. Some benchmark functions are tested in the experiments. The results indicate the algorithm can quickly converge to the optimal solution with quite low cost

Optimum design of PID controllers using only a germ of intelligence

The social foraging behaviour theories of many species provide us with consistent hints to algorithmic approaches for the design of powerful intelligent optimization technology, with direct applications in a high variety of social sciences and engineering fields. In this paper a novel design method for determining the optimal proportional-integral-derivative (PID) controller parameters based on the foraging behaviour of E. coli bacteria is proposed. Bacterial foraging (BF) scheme is selected since it represents an earlier proposal for distributed optimization and control based on natural foraging capacities. The PID controller designed using this method is called the BF-PID controller. In order to assist estimating the performance of the proposed BF-PID controller, a new time-domain performance criterion function was also introduced. To show the validity of the proposed method, two typical control systems were tested. Comparisons with the genetic algorithm (GA) are presented and discussed