基于计算机视觉的大米粒形识别方法

提出了利用计算机视觉系统代替人眼识别整粒大米和碎大米粒形的方法。设计了一套基于计算机视觉技术的大米粒形识别装置,采用灰度变换、阈值分割、平滑处理等图像处理方法获取大米的粒形图像,然后根据大米的粒形特点提取了米粒的面积、周长、长、宽等16个特征参数,采用主成分分析方法对提取的特征参数进行处理,以前三个主成分综合所有粒形特征参数,作为BP神经网络的输入特征值对网络进行训练和大米粒形识别。试验结果表明:该方法对整粒米识别的准确率为98.67%;对碎米识别的准确率为92.09%。

用平板扫描仪及图像处理方法检测大米粒型

提出并用区域跨度定义了米粒粒长及粒宽,即定义米粒区域的最小跨度为米粒粒宽,与此跨度方向垂直的方向上的米粒区域跨度为米粒粒长。根据此定义,通过搜索米粒区域跨度的办法搜索米粒粒长及粒宽,再由米粒粒长及粒宽求出大米粒型。由于此定义与人工对米粒粒长及粒宽的测量方式是一致的,因此,基于此定义的大米粒型检测方法的检测精度高。利用平板扫描仪及图像处理方法检测大米粒型的实验结果表明:用该定义对大米粒型的测量结果相对于人工测量结果的相对误差为1.03%,且该检测方法具有米粒旋转不变性检测的特点。

基于图像处理的大米粒形检测技术研究

传统的大米颗粒检测的方法存在一定的局限性,尝试应用计算机图像处理技术来直接获得大米颗粒的信息。首先对获取的大米图像进行增强处理,在此基础上,研究几种不同的边缘检测算子来实现对大米粒形的检测并比较其结果。实验结果表明,Canny算子对大米粒形检测效果良好,该方法用于大米粒形的识别时对大米的判定正确率较高。

基于Canny算法的大米粒形边缘检测应用研究

目前,数字图像处理在大米外形检测方面已有一定应用。而基于Canny准则的算法在数字图像处理中应用较广,因此,在详细阐明Canny准则及其算法的基础上,讨论了采用Canny边缘检测算子来实现对大米外形的检测并取得了良好的结果。

大米粒形边缘检测算法研究

目前,大米品种主要由人工来检测,由于人为因素的影响,造成检测结果主观性强,一致性差。为了解决这一问题,可以利用计算机对大米品种外形进行检测。基于此,讨论了采用几种不同的边缘检测算子来实现对大米外形的检测并比较其结果。实验表明,该方法用于大米粒形的识别时对大米的判定正确率较高。

图像匹配技术在大米粒形识别中的应用研究

本文提出了一种基于图像相似性匹配技术的大米粒形识别新方法。首先,采用与大米相似的椭圆模板来定位米粒,然后通过算法获取一组与米粒平移、旋转和尺度相关的形状描述数据,提取米粒的特征参数,最终实现大米的识别。试验表明,该方法用于大米粒形的定位与识别时判定正确率较高。

基于改进的边缘检测蚁群算法的大米轮廓检测

在蚁群算法的基础上针对大米轮廓检测提出了一种改进的边缘检测蚁群算法。该算法能有效地检测出米粒的边缘信息,解决了传统大米颗粒检测方法的不稳定和不精确等问题。与此同时,还将其结果与原蚁群算法、Roberts、Sobel和Prewitt等边缘检测算子对图像处理的结果进行了研究对比,实验结果表明,采用改进的边缘检测蚁群算法对大米粒形的检测效果较好,正确率较高,且具有适应性强、效率高等特点。

Microstructure refinement of a dual phase titanium alloy by severe room temperature compression

Microstructure refinement of a dual phase titanium alloy, Ti-3AI-4.5V-5Mo, by severe room temperature compression was investigated. Nanocrystalline grains were observed in the sample with 75% reduction, in which the grain sizes of a phase and β phase were approximately 50 and 100 nm. Conversely, the average thicknesses of a phase and β phase in as-received microstructure were measured to be 0.7 and 0.5 μm, respectively. TEM and XRD methods were used to analyze the microstructure and texture changes after severe deformation. Microstructure refinement was deduced to the complex interaction among slip dislocations in the a phase, the complex interaction among slip dislocations and martensites in the β phases. In addition, the interaction between the a phase and the β phase also contributed to the microstructure refinement.

长不过此生的缘分

我躺在床上,看到皓月当空,繁星璀璨,忍不住想笑。我叫白苏,遇到杜莞尔那年,只有14岁。那是一个阳光灼灼的夏天,我正在上物理课。

“售米无砂”的联想

大礼拜,逢集。米缸空了,便骑单车赶集、籴大米。米市上,麻袋装、竹筐盛,白花花的大米一街两行。我不懂装懂地逐个看成色,问价钱。"俺的便宜,一块五一斤。"我朝前抬头一看,中年汉子正笑嘻嘻地望着我。但他的笑脸并没给我多少信任感,倒是那块插在米袋里的"售米无砂"的招牌激起了我的好奇心,我便上前挪了几步,中年汉子又鼓动巧舌:"您坐机关,上下班怪紧张的,咱这米无砂、干净,放锅添水只管烧就中。不信?您要是吃出一拉砂,下集您再拿来。

选购大米要“五看”

时下正是新米上市的季节,大米按其粘性不同,主要分为三种:籼米、粳米和糯米等。籼米粒瘦而长,膨胀性大,饭粒松散;粳米粒大而白,粘性适中,饭粒柔软香滑,可口耐饥;糯米粒圆而亮,粘性强。时值新米上市时节,有的商贩乘机以次充好。到底怎样鉴别大米质量,选购好大米呢?主要从五个方面着手识别。

科技——生产者和消费者的共同需要

这是一个真实的故事:我有一个从南方调京工作的朋友,一日三餐,只认米饭,不吃面食。他不仅以大米为主食,而且间或还要吃点以米为原料做的各式食品,米粉呀,米糕呀,米饼呀等等。一天,他从商店买来一只家庭多用电动粉碎机,水果、鸡蛋、大米、黄豆,都可粉碎。他如获至宝,搬回家就用大米加工米粉。粉碎机起劲地工作起来,一分钟、两分钟……五分钟。

Effects of Au-Ce strong interactions on catalytic activity of Au/CeO_2/3DOM Al_2O_3 catalyst for soot combustion under loose contact conditions

Au/3DOM（three-dimensionally ordered macroporous） Al2O3 and Au/CeO2/3DOM Al2O3 were prepared using a reduction-deposition method and characterized using scanning electron microscopy,N2 adsorption-desorption,X-ray diffraction,transmission electron microscopy,ultraviolet-visible spectroscopy,temperature-programmed hydrogen reduction,and X-ray photoelectron spectroscopy.Au nanoparticles of similar sizes were well dispersed and supported on the inner walls of uniform macropores.The norminal Au loading is 2%.Al-Ce-O solid solution in CeO2/3DOM Al2O3 catalysts can be formed due to the incorporation of Al^3＋ ions into the ceria lattice,which causes the creation of extrinsic oxygen vacancies.The extrinsic oxygen vacancies improved the oxygen-transport properties.The strong metal-support interactions between Au and CeO2 increased the amount of active oxygen on the Au nanoparticle surfaces,and this promoted soot oxidation.The activities of the Au-based catalysts were higher than those of the supports（Al2O3 or CeO2/3DOM Al2O3） at low temperature.Au/CeO2/3DOM Al2O3 had the highest catalytic activity for soot combustion,with T（10）,T（50）,and T（90） values of 273,364,and 412℃,respectively.

Recent advances in naphtha catalytic cracking by nano ZSM-5:A review

This review discussed the use of nano ZSM‐5 in naphtha catalytic cracking. The impact of nano ZSM‐5 on product selectivity, reaction conversion and catalyst lifetime were compared with micro‐sized ZSM‐5. The application of nano ZSM‐5 not only increased the catalyst lifetime, but also gave more stability for light olefins selectivity. The effects of the reaction parameters of temperature and feedstock on the performance of nano ZSM‐5 were investigated, and showed that high temperature and linear alkanes as feedstock improved light olefin selectivity and conversion.

Quadrature Method of Moments for Nanoparticle Coagulation and Diffusion in the Planar Impinging Jet Flow

A computational model combining large .eddy simulation with quadrature moment method was em-ployed to study nanoparticle evolution in a confined impinging jet. The investigated particle size is limited in the transient regime, and the particle collision kernel was obtained by using the theory of flux matching. The simulation was validated by comparing it with the experimental results. The numerical results show coherent structure acts to dominate particle number intensity, size and polydispersity distributions, and it also induce particle-laden iet to be diluted by .the ambient.The evolution of particle dynarnics in.the impinging jet flow are strongly related to the Rey-nolds number and nozzle-to-plate distance, and their relationships were analyzed.

Bimodal visualization of colorectal uptake of nanoparticles in dimethylhydrazine-treated mice

AIM:To investigate colorectal uptake of solid lipid nanoparticles(SLNs) in mice receiving different doses of 1,2-dimethylhydrazine(DMH) using magnetic resonance(MR) and laser-scanning confocal fluorescence microscope(LSCFM) imaging.METHODS:Eight mice were sacrificed in a pilot study to establish the experimental protocol and to visualize colorectal uptake of SLNs in normal mice.Gadopentetate dimeglumine and fluorescein isothiocyanate(FITC)-loaded SLN(Gd-FITC-SLN) enemas were performed on mice receiving DMH for 10 wk(group 1,n = 9) or 16 wk(group 2,n = 7) and FITC-SLN enema wasperformed on 4 DMH-treated mice(group 3).Pre-and post-enema MR examinations were made to visualize the air-inflated distal colorectum.Histological and LSCFM examinations were performed to verify colorectal malignancy and to track the distribution of SLNs.RESULTS:Homogeneous enhancement and dense fluorescence(FITC) deposition in colorectal wall were observed in normal mice and 1 DMH-treated mouse(group 1) on fluid attenuated inversion recovery(FLAIR) and LSCFM images,respectively.Heterogeneous mural enhancement was found in 6 mice(4 in group 1;2 in group 2).No visible mural enhancement was observed in the other mice.LSCFM imaging revealed linear fluorescence deposition along the colorectal mucosa in all groups.Nine intraluminal masses and one prolapsed mass were detected by MR imaging with different enhancement modes and pathologies.Interstitial FITC deposition was identified where obvious enhancement was observed in FLAIR images.Bladder imaging agent accumulations were observed in 11 of 16 DMH-treated mice of groups 1 and 2.CONCLUSION:There are significant differences in colorectal uptake and distribution of SLNs between normal and DMH-treated mice,which may provide a new mechanism of contrast for MR colonography.

Preparation of Nano-sized Silica-alumina Support by Supersolubilizing Self-assembly Technique

Nano-sized silica-alumina particles were in-situ synthesized in supersolubilizing reverse micellae.Both the most probable pore diameters and the particle sizes were distributed in nano-scale SiO2-Al2O3 particulates.The influence of SiO2/Al2O3 mass ratio and the surfactant content on the particle size and morphology,pore structure,and acidity was characterized by the low temperature nitrogen adsorption/desorption (BET),SEM,TEM and NH3-TPD methods.The test results indicated that the most probable pore diameter of SiO2-Al2O3 nanoparticles was around 10 nm,the specific surface area was about 223-286 m2 /g,the pore volumes were about 0.48-0.63 cm 3 /g,and the particle sizes of porous SiO2-Al2O3 calcined at 550 ℃ were distributed always in the range between 10 nm to 50 nm.The calcined SiO2-Al2O3 nano-powders showed their acidity being stronger than the porous γ-Al2O3 support.