CCD摄像系统镜头的畸变测量

从畸变定义出发,讨论了畸变数学模型,介绍了精密测角法与比长法综合测量畸变的原理。通过放大率法标定出CCD探测器的像素距离当量,通过质心法求出点目标的质心,质心与原点的像素距离乘以像素距离当量得到精确长度。利用正切函数求出绝对畸变值,用最小二乘法解多组数据超定方程,求出拟和公式的系数。实际计算和数据处理结果表明：畸变数学模型在中视场范围内拟合效果很好。     

Design and development of a fiber-optic immunosensor utilizing near-infrared fluorophores

The design and application of a fluorescent fiber-optic immunosensor (FFOI) are reported. The FFOI is utilized for the detection of antibody/antigen binding within the near-infrared (NIR) spectral region. The technique is developed through the combined use of fiber-optic, semiconductor laser-excitation, fluorescence detection, NIR dye, and immunochemical techniques. The antibody is immobilized on the FFOI and utilized as a recognition component for trace amounts of specific antigen. The FFOI is constructed to utilize an antibody sandwich technique. The assay involves the immobilization of the capture antibody on the sensing tip of the FFOI followed by the exposure of the immobilized sensing tip to the antigen. The antigen-coated FFOI is then introduced to a second antibody previously labeled with the NIR dye. Typical measurements are performed in about 15 min. A semiconductor laser provides the excitation (780 nm) of the immune complex. The resulting emission is detected by a silicon photodiode detector (820 nm). The intensity of the resulting fluorescence is directly proportional to the concentration of the antigen. The sensitivity of the analysis reaches 10 ng/ml and the response time is 10–15 min.     

Retinex彩色图像增强理论的物理思考及其截断区间对图像质量的影响

指出了Retinex彩色图像增强理论的物理意义,在对数空间中,将原图像减去高斯函数与原图像的卷积,其物理本质是除去了原图像中的平滑的部分,突出了原图像中的快速变化的部分,而且高斯函数越尖锐,越是突出图像中的细节,高斯函数越平坦,图像色调保持得越好,多尺度Retinex综合了不同高斯函数与原图像进行卷积的优点。研究了多尺度Retinex标准差截断法,结果是,以多尺度Retinex处理后的图像强度在其平均值附近1倍标准差截断后再拉伸得到的图像,普遍好于以2倍、3倍标准差截断后再拉伸得到的图像。     

含散射闪光照相系统的布局优化

为了提高现有照相系统的图像品质,对使用CCD探测器的法国客体(FTO)照相布局进行了优化,获得最佳图像品质因子下的照相布局。研究结果为:在模糊实验测量结果和高斯分布近似下,系统放大倍率为2.0;后保护器件距离客体50 cm;系统布局总长与探测系统的噪声相关,噪声越大,布局总长越短,最优布局总长的范围为3~5 m;实验验证了这一结果。     

煤颗粒热膨胀量与破碎特性的研究

煤颗粒的热膨胀破碎特性直接影响流化床锅炉的运行效率.本文利用热机械分析仪(TMA)测定了不同种类不同密度的型煤和原煤的热膨胀特性,并对部分破碎微观形貌进行了FSEM观察;通过旋转炉内的燃烧试验研究了热膨胀特性和破碎的关系.研究表明,煤颗粒在燃烧过程中其热膨胀破碎主要发生在挥发分析出阶段;内部挥发分的析出会使颗粒内压增大而产生膨胀,进而产生细小裂纹并破碎;挥发分越高,颗粒密度越大,其热膨胀形变率越大,越容易发生破碎现象;主要挥发分析出后热膨胀引起的破碎可以忽略.     

用于光纤熔接系统的纤芯检测镜头设计

光纤已广泛应用于当今社会的信息传输领域。为了满足长距离光纤传输中高质量光纤熔接的需要,介绍了一个应用于光纤熔接系统的透射光纤纤芯检测系统。该系统中的核心器件是一组能对光纤纤芯成像的特殊镜头。借助于ZEMAX软件,设计了这组检测镜头。该镜头具有8倍放大倍率、长工作距离、短结构、高精度等特点。论述了镜头的设计方案和设计过程,并给出了满足要求的设计结果。通过在LightTools软件中对整个系统检测结果的模拟,证明了该设计的可行性。     

Characterization of cold-sprayed nanostructured Fe-based alloy

The ball-milled Fe-Si alloy was used as feedstock for deposition of nanocrystalline Fe-Si by cold spraying process. The microstructure of the as-sprayed nanostructured Fe-Si was characterized by using optical microscopy, scanning electron microscopy and transmission electron microscopy. The grain sizes of the feedstock and as-sprayed deposit were estimated based on X-ray diffraction analysis. The microhardness and coercivity of the deposited Fe-Si alloy were characterized. The results showed that the as-sprayed deposit presented a dense microstructure. The mean grain size of the as-deposited Fe-Si was several tens nanometers and comparable to that of the corresponding milled feedstock. The temperature of driving gas presented little effect on the microstructure of cold-sprayed nanostructured Fe-Si deposit. The mechanical alloying induced oxygen contents up to 8 wt% in the feedstocks and subsequent deposits. The microhardness of the deposit reached about 400 Hv. The deposit achieved a high coercivity up to 190 kA/m indicating the potential possibility for applications to recording materials.     

小位移条件下混沌隔振装置的设计与研究

本文根据混沌隔振原理, 设计出小位移下的混沌隔振装置, 该装置能够在小位移下产生强非线性, 并且其线性部分与非线性部分完全区分开, 实验中易于调节其整体刚度, 以及线性和非线性项比例, 大大增加了该装置在工程中的应用前景. 并利用数值计算方法对特定参数下的隔振装置在简谐激励力作用下的运动进行分析, 证实了该混沌隔振装置的可行性.     

基于线偏振光反射率测量介质折射率的研究

研究线偏振光的振幅反射率与介质折射率的关系,提出一种测量介质材料折射率的方法。文中从菲涅耳公式出发,推导出各向同性介质的线偏振光反射率与折射率的关系式,给出基于线偏振光反射率测定介质折射率的原理。设计实验方案,在不同入射角情况,定出线偏振光p方向和s方向两种线偏振光在玻璃表面的反射率,得到线偏振光振幅反射率随入射角变化的实验曲线。依此实验数据得出材料的折射率。结果表明,测出的介质材料的折射率与理论值相符,所采取的测定方案可行。     

环境气体种类对激光烧蚀粒子速度劈裂的影响

采用蒙特-卡罗(Monte Carlo)方法, 模拟了激光烧蚀粒子输运动力学过程, 在环境气体压强为100 Pa的情况下, 研究了环境气体种类(He, Ne, Ar和假想气体等)对烧蚀粒子速度劈裂的影响. 研究结果表明, 在四种环境气体中传输的烧蚀粒子均出现了速度劈裂现象, 形成速度劈裂所需时间按He, Ne, 假想气体和Ar的次序减小. 还研究了环境气体分子的质量和半径对烧蚀粒子速度劈裂的影响, 形成速度劈裂所需时间随环境气体分子半径(或质量)增大而减小. 在假想气体中, 两速度峰强度相等时的强度最小. 结合欠阻尼振荡模型和惯性流体模型, 对劈裂的形成时间进行了解释. 所得结论可为进一步定量研究纳米晶粒生长机理提供基础.     

4 MV激光触发多级多通道开关特性

 报道了4 MV激光触发多级多通道开关的结构设计和初步的实验结果及分析。该开关采用轴向聚焦触发方式，设计为匀场结构，采用场调整环与匀压环调整开关间隙电场分布，电极-绝缘子序列采用堆栈结构替代榫接结构，独立定位、紧固。实验结果表明：4 MV激光触发多级多通道开关的自击穿电压偏差小于5%，自击穿电压与工作气压呈良好的线性关系；触发延迟时间约25 ns，极差小于±2.5 ns，抖动1.5 ns；等工作电压-气压比条件下，随着气压和工作电压的上升触发延迟时间及其抖动趋向下降。     

延时法测量条纹相机μs档扫描非线性

为实现μs档条纹相机扫描非线性标定,建立了基于延时可调信号源和外触发激光器的条纹相机μs档扫描非线性标定系统,弥补了标准具法的不足。系统通过延时值的递增,得到条纹相机扫描速度在全扫程的变化。系统中时间关系抖动来源主要是测试设备延时抖动和条纹相机触发延时抖动。时间抖动测试与分析显示,条纹相机延时抖动±0.6ns,测试设备延时抖动±0.3ns,系统总时间抖动±0.7ns。系统时间抖动会造成最终时间轴信息的起伏。大量数值模拟分析表明,时间轴起伏对系统时间抖动的影响±2ns,在可以接受的范围内。因此,该系统能够胜任条纹相机μs扫程时间信息的测量标定。     

小孔阵列式太阳敏感器的光学系统设计

微型数字式太阳敏感器光学系统由APS CMOS图像传感器和基于MEMS工艺的小孔阵列式光线引入器组成。图像传感器的分辨率为1024×1024pixel,像素尺寸为10μm×10μm;光线引入器具有微小孔阵列结构,小孔为方形孔,30×30阵列,尺寸为60μm×60μm,间距为250μm。光线引入器采用了MEMS工艺的掩模板制备工艺。针对所设计的光学系统计算了曝光时间,并在此基础上进行了地面成像实验。实验结果表明,光学系统设计合理,保证了敏感器所具有的高精度和大视场。     

助熔剂对无机质子导体BaZrO_3结构及形貌的影响

利用高温固相法制备了无机质子导体BaZrO3。研究了助熔剂的添加对材料的合成温度及微观形貌的影响。通过添加LiF及Li2CO3为助熔剂,可以在1500℃,保温8h合成很好的单相样品。且LiF为助熔剂制备样品的结晶性明显高于Li2CO3为助熔剂制备的样品。XRD精修表明所合成的样品为很好的单相样品。能带计算分析样品的带隙为3.236eV。通过加入LiF及Li2CO3为助熔剂,明显改善了样品的微观形貌,其中LiF为助熔剂样品的颗粒尺寸较小、团聚少,分散性好。当LiF及Li2CO3添加量为8%时,晶界处有小颗粒析出,这种小颗粒为提高材料的质子导电性提供了潜在的可能性。     

掺氮金刚石的光学吸收与氮杂质含量的分析研究

研究了金刚石光学特性与氮杂质及其含量的关系,从传统的金刚石氮含量标定方法出发,修正了金刚石氮含量的计算方法,并且用添加叠氮化钠的原料在六面顶压机上进行了高氮含量金刚石的制备研究.随着体系中叠氮化钠的添加,金刚石红外吸收谱在800—1400 cm^-1范围的吸收强度相对于基线不断升高,这表明金刚石中存在的氮含量在随着叠氮化钠添加而升高,金刚石在单声子区域吸收强度大大增强.用含叠氮化钠的原料制备的金刚石呈现绿色、墨绿色甚至黑色,颜色的深浅依赖于叠氮化钠添加的多少.傅里叶红外光谱测试结果表明 关键词： 金刚石 光学材料 杂质 红外     

Structure prediction and aromaticity of acenes and phenylenes series. A combination method between asymmetric Kekulé structures

The combination method between asymmetric Kekulé structures (CMAK) was expanded to the structure prediction of a series of acenes and phenylenes. The structures predicted by the CMAK correspond to those calculated by the ab initio molecular orbital (MO) and B3LYP density functional methods. The CMAK can characterize the structures. The aromaticity for the whole ring and each ring in the treated compounds was estimated by the index of deviation from aromaticity (IDA). The estimated aromaticity corresponds fairly well to the characterization of the structure predicted by the CMAK. The predicted structures of linear acenes reveal the aromaticity of the central ring and also explain its reactivity. The side ring in [n]phenacene shows high aromaticity. The critical difference in the structure and aromaticity for the central six‐membered ring of the isomers benzo[1,2:4,5]dicyclobutene and benzo[1,2:5,6]dicyclobutene was explained. Copyright © 2012 John Wiley & Sons, Ltd.     

Studies on growth and characterization of l-alanine strontium chloride trihydrate single crystals for optical applications

The optically transparent nonlinear optical single crystals of l-alanine strontium chloride trihydrate (LASCT) were grown by slow evaporation solution growth method using water as solvent. The purity of the crystals was increased by the method of recrystallization. The grown crystals were analyzed by the single crystal X-ray diffraction pattern which proved that LASCT belongs to monoclinic crystal system. The presence of various functional groups and modes of vibrations were identified by FTIR spectroscopy. The optical absorption study confirms the suitability of the crystal for device applications. The thermal strength and the decomposition of the grown crystals were studied using TG/DTA analyses. The dielectric constant and dielectric loss measurements of the grown crystals at different frequencies of the applied field were measured and reported. The mechanical strength of the crystal is estimated by Vicker's hardness test. The nonlinear optical properties of the grown crystals were confirmed by second harmonic generation test which shows the suitability of NLO applications.     

Ku波段球体目标系的电磁复合散射研究

研究了球形目标之间的电磁相互作用,得到了目标二次散射场的表达式,给出了目标的复合散射场以及双站复合散射截面,并在Ku波段进行了数值仿真.结果表明：目标的尺寸对前向散射和后向散射均有较大的影响,周围目标的影响呈现出一定的周期性,二次散射随着目标间距的增大而减小,周围目标离前向散射方向越近,对前向散射的影响也越大.目标的二次散射场与一次散射场强度之比在10^-4数量级以上.在研究多粒子的相互影响时,周围的粒子可近似看作尺寸一定的粒子.利用所得结果以及坐标变换可以研究三维体系内粒子间的电磁相 关键词： 散射截面 二次电磁散射 电磁相互作用     

Investigation on the electronic transport properties of MgS nanotube based molecular devices – a first-principles study

The electronic transport properties of pure MgS nanotube based molecular devices, Mn-substituted nanotubes and Se-substituted nanotubes are investigated using density functional theory. The state of the art of this work is to study the transport properties of MgS nanotubes with substitution impurities across electrodes. The electronic transport properties are discussed in terms of device density of states and transmission spectrum of MgS nanotubes. The effects of Mn substitution and Se substitution in nanotubes are studied. The major contribution to density of states arises only from p orbitals in MgS nanotubes. The substitution effect and bias voltages also have influence in the density of states. The transmission spectrum provides information about the transmission of electrons along the nanotube. The information provided in this work gives a clear vision to fine-tune MgS nanostructures with improved transport property in nanoelectronic device fabrication.     

受阻酚AO-80/丁腈橡胶复合材料的压力-体积-温度关系研究

 研究制备了具有高阻尼性能的受阻酚AO-80/丁腈橡胶复合材料样品,采用动态粘弹性测试得到了损耗因子tan δ与温度T的关系曲线。分析表明,随着受阻酚含量的增加,tan δ峰的位置向高温方向移动,tan δ峰的峰值也逐渐提高;利用pvT高压膨胀计对样品进行了测试,采用Tait方程研究了其压力-体积-温度（pvT）性能,对此计算出Tait方程中的相应参数。结果表明,由Tait方程计算所得的pvT理论关系与定性实验结果一致,具有较好的规律性,即对AO-80/丁腈橡胶复合体系b₁值随AO-80量的增加而逐渐降低,AO-80量越大,该体系T_g时的绝对比容越小;b₂随AO-80量的增加而逐渐增大,AO-80量越大,该体系随温度膨胀越显著;b₃、b₄均为常数,即B为常数,复合材料的比容只与压力存在一定关联;同时用Tait方程计算所得的值与实验值的平均残差均小于0.02,吻合度较好;结果表明,Tait方程可以较好地描述该体系的pvT关系,为定量研究阻尼材料的pvT性能提供了理论指导。