表面粗糙度对黑云斜长片麻岩不同探测角偏振度波谱影响研究

以黑云斜长片麻岩为例,探讨了表面粗糙度因子在350～2 500nm波段对岩石不同天顶角及方位角偏振度探测的影响,并在特征波段进行了定量分析。表明不同粗糙度的岩石表面,入射天顶角一定时,在镜面反射方位,偏振度随探测天顶角先是上升,到达最高值后又开始下降。(520±10)nm波段的偏振度在探测天顶角方向达到的最大峰值与表面粗糙度进行相关分析,发现他们呈幂函数关系。回归方程为:y=0.604x-0.297,可决系数R2为0.985 4。峰值所在天顶角度与表面粗糙度相关模型为,y=3.419 4x+51.584,y<90°,模型可决系数R2为0.817 7。偏振度随探测方位角变化的规律为以180°方位时偏振度最大,向两侧随探测方位离180°越远逐渐越低,并趋于0。(520±10)nm波段的偏振度在探测方位角180°方向达到的最大峰值与表面粗糙度进行相关分析,发现他们呈幂函数关系。回归方程为:y=0.582 2x-0.333,可决系数R2为0.984 3。对以上回归模型进行F检验,发现偏振度峰值及所对应角度与粗糙度之间存在显著的相关关系。     

Degree of paraxiality of a stochastic electromagnetic Gaussian Schell-model beam

The concept of the degree of paraxiality introduced recently for monochromatic fields is extended to the domain of stochastic electromagnetic fields. Analytical expression for the degree of paraxiality of a stochastic electromagnetic Gaussian Schell-model (EGSM) beam is derived. Numerical results show that the degree of paraxiality of an EGSM beam is determined by the degree of polarization, r.m.s. widths of the spectral densities and of the correlation functions of its source. Degree of paraxiality of an EGSM beam after passing through a linear polarizer is also analyzed. Our results show that one can modulate the degree of paraxiality of an EGSM beam by a linear polarizer.     

DICYCLOHEXYLCARBODIIMIDE ASSISTED SYNTHESIS OF ALIPHATIC POLYESTERS AT ROOM TEMPERATURE

We investigated the use of dicyclohexylcarbodiimide (DCC) as an activating agent in the synthesis of aliphatic polyesters. Butylhexanoate was synthesized in order to optimize the reaction conditions. The reactions were carried out in methylene chloride at room temperature. It was shown that nearly complete conversion is achieved if 4-(dimethylamino)pyridinium 4-toluenesulfonate (DPTS) is used as the catalyst. DPTS is a complex formed from 4-(dimethylamino)pyridine (DMAP) and p-toluenesulfonic acid (PTSA). The polyesters based on 1,10-octanedicarboxylic acid and 1,4-butanediol, synthesized in this way, had degrees of polymerization up to 67.     

部分相干贝塞尔高斯光束在非柯尔莫哥诺夫湍流中的传输特性

根据广义惠更斯-菲涅耳原理,推导出了部分相干贝塞尔高斯光束在非柯尔莫哥诺夫湍流中传输时平均光强和偏振度的解析表达式,研究了部分相干贝塞尔-高斯光束在非柯尔莫哥诺夫湍流模型下的光强分布特征和偏振度变化规律,同时分析了指数项、折射率结构常量、湍流内外尺度以及拓扑荷、光源相干性等对光束传输性质的影响.数值计算表明,随着传输距离的增加,部分相干贝塞尔高斯光束的光强会从空心分布逐渐演变为高斯分布,同时光束会有一定程度的展宽.而且,当指数项值越接近于3.1,折射率结构常量越大,外尺度越大或者内尺度越小时,光强分布的演变越为迅速,展宽现象也越明显;当拓扑荷越小或者相干长度越小时,光强分布的演变越迅速,但是二者对展宽现象的影响并不明显.另外,偏振度在近距离处会经历一段振荡及升降变化过程,当距离足够远时会趋于一个稳定值,且该值等于光源平面上的初始偏振度.偏振度变化的快慢程度受指数项、折射率结构常量、湍流内外尺度、拓扑荷和相干长度等因素的影响.     

基于洛匈棱镜的偏振度测量与空间退偏度分析方法研究

空间平均型退偏要求退偏后的光束不仅具有低偏振度,还要求避免偏振态的空间带状连续分布.为了实现光束偏振度的测量和空间退偏度的观察,提出基于洛匈棱镜的偏振度测量方法,理论推导了偏振度和各个光功率测量值之间的关系,设计了实验装置,并与全偏振度测量方法进行对比.结果显示:两种测量方法得到的偏振度相对偏差为0.192%,但洛匈棱镜能将o光和e光在空间分离,能对光束偏振态的空间分布进行观测.基于洛匈棱镜的偏振度观测方法结构简单,操作方便,在偏振度和偏振态的空间分布的同时观测中有重要应用.     

Prediction of coating uniformity in batch fluidized-bed coating process

Coating of particulate materials in fluidized beds is a widely used technique to eliminate particle agglomeration, provide slow release of an active substance, or protect active ingredients. When thin polymer shells are applied on a particle surface, it is important to determine the process parameters that provide coating uniformity. In this study, the degree of coverage, defined as the fraction of the coated surface of the particles, is proposed as a quantitative criterion of coating uniformity. A new model for the batch fluidized-bed coating process is presented. The model allows prediction of the function of particle distribution according to the degree of coverage at a given process time and thereby enables assessment of coating uniformity. An algorithm for the numerical solution of model equations for a batch fluidized-bed coater is described. The influences of the main process parameters on the coating uniformity were shown.     

On connection sequence for equivalent polynomial sets

The main purpose of this paper is to study the connection sequence between two polynomial sets. We prove that any two equivalent polynomial sets can be connected with a Sheffer sequence. The principal result presents a unification of some useful known results. The inversion, addition and duplication sequences are considered as particular cases. Moreover, some examples are given.     

基于无人机近地面多光谱图像的蛇龙珠葡萄成熟度判别

酿酒葡萄一般批量采收,采收期对其品质有较大影响。传统方法主要依靠对样本的酚、糖等各组分含量进行实验室理化指标检测,判定采收成熟度。如果对多个地块进行采摘前的连续监测,则批量大、成本高、采样与分析工作量繁重,且时效性差,难以保证果品的收获品质。以蛇龙珠品种为对象,提出一种利用近地面多光谱图像对种植区葡萄成熟度和批量采收期判别的方法。通过DJI Phantom四旋翼无人机搭载ADC Micro多光谱相机,以S型采样路线直接拍摄9个采样点的蛇龙珠田间原位图像,并采集葡萄果粒样本;利用PixelWrench2 x64软件进行图像处理,得到每张图像的红色（R）分量、绿色（G）分量、近红外（NIR）分量值;将葡萄果粒榨汁,依据检测时长、成本和代表性程度,选取总糖含量为成熟度判定指标,采用PAL-1手持式糖度仪检测葡萄汁总糖含量;分别分析R,G,NIR分量与日期的显著性关系,发现叶片集中区域（局部）的R分量与日期为最显著关系（p-value=5.314 44×10-4,调整后R2=0.815）,可作为建模的成熟度参数;按照模型集与验证集为4∶1的原则构建“总糖含量-局部R分量”线性回归与对数回归模型,结果显示：相比于线性模型,总糖含量与局部R分量呈非常显著的对数关系（p-value=5.124 07×10-10,调整后R2=0.970 62）,且该模型的平均预测误差≤1.388%、最大预测误差≤4.6%、采收前预测误差±0.46%,证明该对数模型具有较高的检测精度。实际采收前,利用上述方式在近采收期采集蛇龙珠葡萄田间原位多光谱图像,将得出的局部R分量值带入对数模型,可对总糖含量进行预测,并以22%±0.46%的总糖含量为标准研判蛇龙珠葡萄是否成熟。结果表明：采用区块光谱图像进行酿酒葡萄的批量采收品质和采收时间预测具有便利性与可行性,为光谱图像在农业实际生产中的应用提供了新思路。