基于Zernike矩的米粒形状模糊分类

根据米粒形状的特征,运用Zernike矩描述目标边缘的形状,采用模糊模式识别方法,实现按形状分类.为增强适应能力,对Zernike矩及模糊分类方法作了适当调整.对300颗同一品种的米粒进行实验,结果表明,本方法的检测结果与人工检测结果高度一致.

杂交水稻谷粒形状和米粒形状相关分析

对杂交水稻 9个组合的稻谷和米粒的长宽比作相关分析 ,得知 9个组合米粒形状由谷粒形状决定 ,二者呈极显著正相关。F1代的谷。

人体“小舌头”

人体＂小舌头＂傅德明＂小舌头＂是悬雍垂的俗称，每个人张嘴可见，长约１厘米，很像咽喉大门中间倒挂着的一个小灯泡，位居口腔上膛后缘的中央，其前面是口腔，后面是鼻咽部，成为两者交界的唯一标志。悬雍垂其表面覆盖着一层粘膜上皮，借助于显微镜观察，可见这层上皮是...

新型美味营养米

美味营养米是以山药、土豆、小麦、高粱、大米的淀粉为主要原料加工而成的新型食品。其营养全面、口味鲜美。适合农村和农户搞加工。

Preparation of Well-shaped Microcapsule Immobilizing Inorganic Nanoparticles

A facile and efficient method has been developed for microencapsulation of metal oxide nanoparticles in polyurea via interfacial polymerization of toluene-2,4-diisocyanate and H20 through the atomizing emulsification approach. The resultant microcapsules were well-shaped and uniform sphere with diameter ranging from 2 to 6 um. Thermogravimetry （TG） and differential scanning calorimetry （DSC） curves revealed that the microcapsules showed good thermal stability （no decomposition observed under 245℃）. Besides, the microencapsulated TiC2 has been used as an efficient catalyst for photocatalytic degradation of methyl orange. Furthermore, the photocatalysis of immobilized TiC2 could be enhanced by introducing UV absorbing agent to the wall of microcapsules.

Preparation and shape memory properties of TiO_2/PLCL biodegradable polymer nanocomposites

The preparation of TiO2/poly（L-lactide-co-ε-caprolactone）（PLCL） nanocomposites and their properties were reported.TiO2nanoparticles were surface modified by ring-opening polymerization of ε-caprolactone（ε-CL）.The resulting poly（ε-caprolactone）-grafted TiO2（g-TiO2） was characterized by Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TGA） and transmission electron microscopy（TEM）.The g-TiO2can be uniformly dispersed in chloroform and the g-TiO2/PLCL nanocomposites were successfully fabricated through solvent-casting method.The effects of the content of g-TiO2nanoparticles on tensile properties and shape memory properties were investigated.A significant improvement in the tensile properties of the 5% g-TiO2/PLCL mass fraction nanocomposite is obtained：an increase of 113% in the tensile strength and an increase of 11% in the elongation at break over pure PLCL polymer.The g-TiO2/PLCL nanocomposites with a certain amount of g-TiO2content have better shape memory properties than pure PLCL polymer.The g-TiO2nanoparticles play an additional physical crosslinks which are contributed to improvement of the shape memory properties.

Inhalation treatment of lung cancer: the influence of composition, size and shape of nanocarriers on their lung accumulation and retention

Objective： Various nanoparticles have been designed and tested in order to select optimal carriers for the inhalation delivery ofanticancer drugs to the lungs. Methods： q-he following nanocarriers were studied： micelles, liposomes, mesoporous silica nanoparticles （MSNs）, poly propyleneimine （PPI） dendrimer-siRNA complexes nanoparticles, quantum dots （QDs）, and poly （ethylene glycol） polymers. All particles were characterized using the following methods： dynamic light scattering, zeta potential, atomic force microscopy, in vitro cyto- and genotoxicity. In vivo organ distribution of all nanopartides, retention in the lungs, and anticancer effects of liposomes loaded with doxorubicin were examined in nude mice after the pulmonary or intravenous delivery. Results： Significant differences in lung uptake were found after the inhalation delivery of lipid-based and non-lipid-based nanoparticles. The accumulation ofliposomes and miceUes in lungs remained relatively high even 24 h after inhalation when compared with MSNs, Q Ds, and PPI dendrimers. There were notable differences between nanoparticle accumulation in the lungs and other organs 1 and 3 h after inhalation or intravenous administrations, but 24 h after intravenous injection all nanoparticles were mainly accumulated in the liver, kidneys, and spleen. Inhalation delivery of doxorubicin by liposomes significantly enhanced its anticancer effect and prevented severe adverse side effects of the treatment in mice bearing the orthotopic model of lung cancer. Conclusion： The results of the study demonstrate that lipid-based nanocarriers had considerably higher accumulation and longer retention time in the lungs when compared with non-lipid-based carriers after the inhalation delivery. These particles are most suitable for effective inhalation treatment of lung cancer.

Frabrication of Au Nanoparticles in Various Shapes and Their Application in Surface-enhanced Raman Scattering

Anisotropic metallic Nanoparticles （NPs） have unique optical properties, such as Surface Enhanced Raman Scattering （SERS） spearoscopy. In this paper, star-shaped and sphere gold NPs were prepared by seed-mediated growth and Frence methods respectively. The reaction process arid the effect of reagent in seed-mediated growth of gold naaostar particles were systematically described. After fabricaring NPs the authors test their Raman enhancement using Ch-ystal Violet （CV） moleolles apart. The experimental results indicated that star-shaped Au NPs had strtmger Raman enhancement spectrum than that of sphere Au NPs.

Change in Aggregate Shape of Heat Treated Carbon Nanoparticles

To better understand the fusion mechanism of heated carbon black, heat treatment is conducted for carbon black produced by benzene pyrolysis. The effects of （a） heating time, （b） heating temperature and （c） heating rate on the aggregate shape and mean primary particle diameter of the carbon black are investigated using TEM （transmission electron microscopy）. The mean primary particle diameter does not change significantly when carbon black is heat treated. For short heating times and low heating temperatures, the aggregate shapes become simple when compared with those of non-heated carbon black, and shapes become complex with an increase in the heating time. Also, for low heating rates, the aggregate shapes become significantly simple when compared with those of non-heated carbon black. The results of this study suggest that sintering between primary particles is promoted under relatively low heating temperatures, and Ostwald ripening among aggregates is promoted under relatively high heating temperatures.

Ag3PO4 colloidal nanocrystal clusters with controllable shape and superior photocatalytic activity

Cluster-like Ag3PO4 nanostructures including nanoparticles, trisoctahedrons, tetrahedrons and tetrapods have been prepared by the synergetic reaction of Ag nanocrystals, phosphate anions and hydrogen peroxide. The acidity and alkalinity of the reaction solution are tuned to adjust the oxidizing ability of H2O2, and thus control the final morphology. Ag nanocrystals function as a sacrificial precursor, leading to the generation of clusterqike nanostructures. Through a kinetic study, the formation of Ag3PO4 nanocrystal clusters can be understood as the conversion from Ag to AgBPO4 nanocrystals assisted by H2O2, followed by the oriented attachment of nanocrystals into cluster-like colloids with specific shapes. The as-prepared AgBPO4 nanostructures have higher photocatalytic activity than commercial TiO2 and some reported AgBPO4 microcrystals in the degradation of dyes. The catalytic activity decreases in the order nanoparticles 〉 trisoctahedrons 〉 tetrahedrons 〉 tetrapods, while the stability increases in the order nanoparticles 〈 tetrahedrons 〈 trisoctahedrons 〈 tetrapods, which can be explained by the extent of absorption of visible light and structural factors, including size and exposed crystal facets.

First-principles calculations of the dissolution and coalescence properties of Pt nanoparticle ORR catalysts： The effect of nanoparticle shape

The degradation of Pt nanoparticles （NPs） in fuel cell cathodes leads to the loss of the precious metal catalyst. While the effect of NP size on Pt dissolution has been studied extensively, the influence of NP shape is largely unexplored. Because of the recent development of experimental methods to control the shape of metal NPs, rational guidelines/insights on the shape effects on NP stability are imperative. In this study, first-principles calculations based on density functional theory were conducted to determine the stability of 1-2 nm Pt NPs against Pt dissolution and coalescence with respect to NP shape. Toward dissolution, the stability of the Pt NPs increases in the following order： Hexagonal close-packed 〈 icosahedral 〈 cuboctahedral 〈 truncated octahedral. This trend is attributed to the synergy of the oxygen adsorption strength and the local coordination of the Pt atoms. With respect to coalescence, the size of a NP is related to its propensity to coalesce or detach/migrate to form larger particles. The stability of the Pt NPs was found to increase in the following order： Hexagonal close-packed 〈 truncated octahedral 〈 cuboctahedral 〈 icosahedral, and was correlated with the cohesive energies of the particles. By combining the characteristic stabilities of the shapes, new ＂metal-interfaced＂ Pt-based coreshell architectures were proposed that should be more stable than pure Pt nanoparticles with respect to both dissolution and coalescence.

Shape-controlled Pt nanocubes directly grown on carbon supports and their electrocatalytic activity toward methanol oxidation

Synthesis of shape-controlled Pt nanocrystals is substantial and important for enhancing chemical and electrochemical reactions.However,the removal of capping agents,shape-controlling chemicals,on Pt surfaces is essential prior to conducting the catalytic reactions.Here we report a facile one-pot synthesis of Pt nanocubes directly grown on carbon supports(Pt nanocubes/C) with modulating the kinetic reaction factors for shaping the nanocrystals,but without adding any capping agents for preserving the clean Pt surfaces.Well-dispersed Pt nanocubes/C shows enhanced activity and long-term stability toward methanol oxidation reaction compared to the commercial Pt/C catalyst.

Measuring the number concentration of arbitrarily-shaped gold nanoparticles with surface plasmon resonance microscopy

Molar concentration of gold nanoparticles is one of the most critical parameters of gold colloids in order to develop their applications in sensing, diagnostics and nanomedicine. Previous methods often stand just for gold nanoparticles with regular shape and narrow size distribution. In the present work, we proposed an absolute quantification method that determined the molar concentration of gold nanoparticles with arbitrary shapes and polydisperse sizes. This approach involved the real time monitoring and counting of individual nanoparticles collision events, from which the quantification of molar concentration was achieved using a theoretical model consisting of Fiek＇s laws of diffusion and Stokes-Einstein equation. The determination of spherical gold nanoparticles concentration resulted in excellent agreement with traditional spectrometry method. It was further demonstrated that the present approach can be expanded to determine the molar concentration of gold nanoparticles with arbitrary shapes and poly-diversed distributions.

A large stroke magnetic fluid deformable mirror for focus control

A liquid deformable mirror, which can provide a large stroke deflection more than 100 μm, is proposed for focus control. The deformable mirror utilizes the concept of magnetic fluid deformation shaped with electromagnetic fields to achieve concave or convex surface and to change the optical focus depth of the mirrors. The free surface of the magnetic fluid is coated with a thin layer of metal-liquid-like film(MELLF) prepared from densely packed silver nanoparticles to enhance the reflectance of the deformable mirror. The experimental results on the fabricated prototype magnetic fluid deformable mirror(MFDM) show that the desired concave/convex surface shape can be controlled precisely with a closed-loop adaptive optical system.

Controlled synthesis and shape-dependent electromagnetic wave absorption characteristics of porous Fe_3O_4 sub-micro particles

Porous Fe3O4 sub-micro particles with sphere-like, cube-like and walnut-like morphologies were obtained by a two-step process, and the electromagnetic properties of the Fe3O4 particle/wax composites were investigated. The reflect loss was less than -20 dB for all of the composites in different frequency ranges. The cube-like and walnut-like Fe3O4 composites exhibit improved complex permittivity and permeability and dual-frequency and wide bandwidth absorption characteristics, which is mainly attributed to the larger shape anisotropy. Such a high absorption property indicates that these porous Fe3O4 particles with various morphologies are very promising for electromagnetic wave absorptive materials.