Gạo gia công

Gạo gia công

Kết quả (Anh) 1:

Processed rice

Kết quả (Anh) 2:

Master rice

Kết quả (Anh) 3:

In recent years, the development of Nanoparticles and Quantum Dots materials has attracted attention because the optical properties and electrical properties of materials can be controlled by changing particle sizes, and some of their basic prop-erties, such as optical, electrical, magnetic, and mechanical properties. These properties will change when the crystal particle size is as small as the nanoscale, and their energy gaps (Band Gap) change the original continuous energy band to dis-continuity due to quantum limiting effects. Nanoparticles of different particle sizes have different wavelengths of light, so they can be controlled by controlling the particle size of the material, and then adjusting their luminous wavelength.When the particle size of the material is smaller than the Bohr radius, it is called a quantum dot, and the quantum confinement effect will also appear at the same time. Quantum dots are a powerful imaging and tracing tool that can replace traditional organic dyes and reinforce the deficiencies of organic dyes, such as short life cycle, narrow excitation range, and low fluorescence emission intensity, Therefore, it will be widely used in biomedicine, such as disease diagnosis and pre-diction, cell tracking, cell vitality observation, fluorescent emission as a marker for the observation of in vivo static and dynamic images . This is just one of the applications of quantum dots in different fields. Others such as sensors 【】, solar cells, laser materials, electronic materials, composite materials, light-emitting di-odes 【】】,etc., all have great application value.Cadmium sulfide is a typical II. - VI. semiconductor material. When its particle size is small to the nanometer scale, it has some unique properties, such as nonlinear optical properties, photoluminescence properties, quantum confinement effects, and other important physical and chemical properties, and has considered application potential in optics, electricity, magnetism, catalysis, and so on. Therefore, several synthesis methods of CdS nanoparticles have been developed, such as the micro-emulsion method, photochemical method, and sol-gel method. There are many ways to synthesize quantum dots, such as microemulsion, sol-gel, photochemical and solvothermal methods. Datta et al. used CdCl2 and Thi-ophenol as the precursors, and methanol as the solvent for γ-ray irradiation to syn-thesize cadmium sulfide nanoparticles. In their study, changing the ratio of Cd2+ / Thiol and the influence of irradiation intensity on the particle size of cadmium sul-fide. The conclusion shows that the size of cadmium sulfide nanoparticles will be in-crease with the increase of γ-ray irradiation intensity. The particle size of cadmium sulfide synthesized by changing different parameters is about 3-5 nm【9】. Wang et al. used CdCl2, Na2S2O3 as the precursors and Polyvinylpyrrolidone (PVP) as the coat-ing agent to synthesize the CdS/SiO2 core-shell structure to improve the photolumi-nescence properties.Different from the traditional synthesis method, the size distribution of the synthesized nanoparticles is uniform and the synthesis time is shortened. Therefore, in this study, CdS quantum dots were synthesized by synchrotron radiation X-ray with different synthesis parameters, such as the molar ratio of precursor CdSO4 and Na2S2O3, and different synthesis times. In addition, we also tried to synthesize CdS Nanoparticles by micro emulsification with different concentrations of carrier and surfactant. By using synchrotron radiation X-ray irradiation to synthesize quantum dots, which belongs to a new synthesis method and is somewhat similar to the photochemical synthesis method. This method can effectively shorten the synthesis time of quan-tum dots in a few minutes, and the synthesized quantum dots have a small particle size and uniform particle size. Therefore, we adopt synchrotron radiation X-ray irra-diation to synthesize CdS quantum dots.