Preparation and photocatalytic activity of composite films containing clustered TiO2 particles and mineral tourmaline powders

The novel composite films containing clustered TiO2 particles and fine tourmaline particles on the surface of copper webs were prepared by the sol-gel method. The microstructures of the composite films were investigated by scanning electron microscopy （SEM）, and the photocatalytic activity of the films was evaluated by photocatalytic degradation of methyl orange, respectively. The results indicate that tourmaline particles can obviously influence the microstructures of TiO2 films and enhance the photocatalytic activity due to their spontaneous permanent polarity and high radiotechnology of far infrared. During preparing the composite films, the clustered TiO2 particles with lots ofnano-sized ladder layers can grow on the surface of fine tourmaline particles, the thickness of ladder layer is 10 nm, and the average diameter ofnano-sized TiO2 particles is 15 nm.     

电渣熔铸冷交换器顶盖

采用电渣技术试生产的冷交换器顶盖，组织致密、非金属夹杂物少，力学性能优于同类产品锻件，解决了顶盖产品锻件难于通过超声波探伤的难题。     

融合CNN和Bi-LSTM的miRNA-lncRNA互作关系预测模型

非编码RNA(ncRNA)在很多动植物生命活动方面起着重要的调节作用,而微小RNA(miRNA)与长非编码RNA(lncRNA)的相互作用更为重要,其互作关系的研究不仅有助于深入分析基因间生物学功能,也可为疾病的诊治和植物的遗传育种方面提供新思路.目前,miRNA-lncRNA互作关系的预测大多使用生物实验和传统机器学习方法.由于生物鉴定代价高耗时长和机器学习涉及过多人工干预且特征提取过程复杂,在此提出一种融合卷积神经网络(convolutional neural network, CNN)和双向长短期记忆网络(bidirectional long short-term memory network, Bi-LSTM)的深度学习模型,兼备两者优势,既考虑序列间信息相关性和结合上下文信息,又能充分提取序列数据的特征.采用交叉检验评估模型性能,在玉米数据集上与传统机器学习方法和单一模型比对,取得较优的分类效果.另外,采用马铃薯和小麦数据集进行模型测试,准确率分别达到95%和93%以上,验证了模型具有良好的泛化能力.     

融合粒子群优化和遗传算法的基因调控网络构建

MicroRNA（miRNA）是一类大小为21~25 nt的内源性非编码小核糖核酸（RNA）,通过与mRNA的3’-UTR互补结合,导致mRNA降解或翻译抑制来调控编码基因的表达。为了提高构建基因调控网络的准确度,提出一种基于粗糙集、融合粒子群（PSO）和遗传算法（GA）的基因调控网络构建方法（PSO-GA-RS）。该方法首先通过对序列信息进行特征提取;然后采用粗糙集的依赖度作为适应度函数,融合粒子群和遗传算法选出较优的特征子集;最后使用支持向量机（SVM）建立模型,预测未知的调控关系。在拟南芥数据集上进行实验,相比基于粗糙集和粒子群优化的特征选择方法和Rosetta算法,所提方法的预测准确率、F值和受试者工作特征（ROC）曲线面积最多能提高5%,在水稻数据集上最多能提高8%。实验结果表明所提方法能够比较准确地预测miRNA和靶基因之间的调控关系。     

用反符合和热中子屏蔽降低γ谱仪本底

新建的一台反宇宙射线低本底HPGeγ谱仪,在物质屏蔽的基础上采用反符合和热中子屏蔽联合方法,实验研究次级宇宙射线μ子和中子产生的本底。结果表明,反符合屏蔽(塑料闪烁探测器)能大幅度降低μ子产生的本底,还能有效抑制快中子与锗晶体和屏蔽材料非弹性散射引起的本底,100-2000keV能区反符合积分本底抑制系数可达8倍。热中子屏蔽(镉吸收片)的加入可明显降低锗晶体和屏蔽材料热中子俘获产生的本底,使511keV正电子湮灭峰本底的抑制系数由5.8倍提高到20.7倍,100-2000keV反符合积分本底抑制系提高到13.2倍。     

共孔径红外双色离轴全反射系统

以初级像差理论为基础,重点分析了离轴三反系统初始结构参量的确定方法。利用CODEV软件编译计算并生成离轴三反光学系统初始结构的人机交互程序。将红外双色复合成像和离轴全反射系统结合起来,设计了一种共孔径红外双色离轴全反射系统。该系统具有长焦距、大孔径、宽波段、平像场等特点,结构简单,像质优良,在航空航天领域具有广泛的应用前景。     

一种新的双重标记免疫组化图像自动分割方法

本文描述一种自动分割双重标记免疫组化图像的方法,此方法直接从双重标记的两种阳性组织细胞着色特征对其进行分离。与常用的彩色反卷积方法相比,此方法提高了分割准确度且需要样品切片的数量从3张减少到1张。通过细胞角蛋白和S-100蛋白双重标记,分别经二氨基联苯胺(DAB)与3-氨基-9-乙基咔唑(AEC)显色的舌鳞癌样品图像的实验证明,此方法可以有效地将鳞癌与神经组织细胞两种不同的染色区域分割出来,与手动分割的结果作比较其准确度和精确度都有较大的提高。此方法也适用于分割其他用DAB和AEC双重染色的免疫组化图像。     

用于亚公里级三维成像的全光相机主物镜设计

The plenoptic camera can refocus after imaging, and obtain the position and direction information of the target at the same time with one exposure. Compared with the active distance measurement method and the traditional passive distance measurement method, the depth measurement method based on the plenoptic camera has the advantages of being difficult to detect and easy to calibrate. The plenoptic camera 3D imaging technology is a computational imaging technology that integrates the front-end optical system and the back-end information processing. The current research works mainly focus on the back-end information processing algorithm et al. There are few reports on the research of the front-end optical system. Therefore, the design of the front-end optical system was researched. Firstly, a calculation model was established for the depth resolution of a plenoptic camera based on multi-eye vision and the influence of optical system performance parameters was analyzed such as focal length and F-number on the object depth resolution. Secondly, the influence of factors was analyzed such as the blocking ratio of the two-mirror optical system and the magnification of the secondary mirror on the system parameters. Finally, a plenoptic camera main objective optical system for sub-kilometer-scale 3D imaging was designed comprehensively considering the design, processing, assembly, and ranging performance. The focal length of the system is 500 mm, the total length of the system is less than 163 mm, the telephoto ratio is less than 1/3, and the working temperature range is ?40 -70 ℃. The full field of view MTF in 80 lp/mm is better than 0.3 at different temperatures. If the plenoptic camera uses this objective and a sub-pixel recognition accuracy algorithm of 1/8 pixel, a depth resolution of less than 5 m can be obtained at 0.5 km.     

基于二维微透镜阵列增大手术显微镜出瞳直径方法研究

医生使用传统含目镜系统的手术显微镜进行手术,当其头部移动时,该系统仅存在很小的出瞳直径,因而这就迫使医生在手术过程中长时间保持头部在特定位置。可见,传统手术显微镜存在显著弊端:长时间持续观察会增加医生的疲劳度。对使用二维微透镜阵列(microlens array,MLA)增大目视光学系统出瞳直径进行了理论探讨,并用傅里叶光学原理进行了理论分析。并且在此基础上,设计了增大手术显微镜光学系统出瞳直径的二维微透镜阵列器件,该二维微透镜阵列器件中两个折射面相对放置,且两者相距一个微透镜单元焦距的长度。经计算机模拟计算证明,使用该二维微透镜阵列器件可以有效增大目视光学系统出瞳直径,并可获得更加均匀的出射光束。     

钻机油改电技术与钻井工艺适应性研究

石油钻机利用高压电网供电的电驱动方式可消除排放、降低噪声,获得较好的节能效果。分析了高压电网全场供电的总体方案、变频电机驱动方案、高低压配电安全性及无功补偿效果,并进行了变频电动机与钻机机械传动的适应性研究。