Cylindrical components of in situ functionally gradient composite materials of Al-19Si-5Mg alloy were manufactured by centrifugal casting. Microstructure characteristics of the manufactured components were observed an...Cylindrical components of in situ functionally gradient composite materials of Al-19Si-5Mg alloy were manufactured by centrifugal casting. Microstructure characteristics of the manufactured components were observed and the effects of the used process factors on these characteristics were analyzed. The results of observations shows that, in thickness, the components possess microstructures accumulating lots of Mg2Si particles and a portion of primary silicon particles in the inner layer, a little MgzSi and primary silicon particles in the outer layer, and without any Mg2Si and primary silicon particle in the middle layer. The results of the analysis indicate that the rotation rate of centrifugal casting, mould temperature, and melt pouring temperature have evidently affected the accumulation of the second phase particles. Also, the higher the centrifugal rotation rate, mould temperature, and melt pouring temperature are, the more evident in the inner layer the degree of accumulation of Mg2Si and primary silicon particles is.展开更多
Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid （2,4-D） as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale ra...Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid （2,4-D） as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale range. The adsorbing experiments indicated that the imprinted polymer particles possessed higher affinity to 2,4-D than the non-imprinted polymer particles.展开更多
The effect of protons(E = 100 keV,F = 5×10^(15) cm^(-2)) exposure on the diffuse reflectance spectra of the SiO_(2 )with different size particles in wavelength range from 250 to 2500 nm have been investigated.Par...The effect of protons(E = 100 keV,F = 5×10^(15) cm^(-2)) exposure on the diffuse reflectance spectra of the SiO_(2 )with different size particles in wavelength range from 250 to 2500 nm have been investigated.Particles were nanosphere,submicrosphere,microsphere and submacrosphere,as well as solid micro-and nanocrystals.The synthesis of the particles was carried out by the formation of silica shells and dissolution of the polystyrene core particles.The surface morphology,surface area and crystal structure of the particles have been investigated.When evaluating the changes of the solar absorptance,it was found that the radiation stability of the micro-and submacro-hollow particles is higher than that of the other nanostructured particles,except for solid microcrystals.The low radiation stability of the hollow microparticles is due to the large void inside the hollow particles where radiation defects are not formed.展开更多
The low energy particle detector （LEPD） is one of the main payloads onboard the China seismic electromagnetic satellite （CSES）. The detector is designed to ascertain space electrons （0.1–10 MeV） and protons （2...The low energy particle detector （LEPD） is one of the main payloads onboard the China seismic electromagnetic satellite （CSES）. The detector is designed to ascertain space electrons （0.1–10 MeV） and protons （2–50 MeV）. It has the capability of identifying the electrons and protons, to measure the energy spectrum and the incident angle of the particles. The LEPD is made up of a silicon tracker system, a CsI （Tl） mini-calorimeter, an anti-coincidence system made by plastic scintillator, as well as electronics and a data acquisition system （DAQ）. The tracker is also a kind of E-E telescope; it consists of two layers of double-sided silicon strip detectors （DSSD）. The signals emerging from the silicon tracker can be read out by two pieces of application specific integrated circuit （ASIC）, which also can generate an event trigger for the LEPD. The functions of the DSSD system in the LEPD for charged particles were tested by 241Am @5.486 MeV α particles. The results show that the DSSD system works well, and has high performance to detect charged particles and measure the position of incident particles.展开更多
针对Na_(2)O-CaO-SiO_(2)(NCS)多孔微晶玻璃内部气孔大小不同、分布不均问题,提出通过添加固态Si颗粒调控NCS多孔微晶玻璃孔结构。通过扫描电子显微镜(SEM)、图像处理软件Image pro plus 6.0、DSC等分析手段研究固态Si颗粒对NCS多孔微...针对Na_(2)O-CaO-SiO_(2)(NCS)多孔微晶玻璃内部气孔大小不同、分布不均问题,提出通过添加固态Si颗粒调控NCS多孔微晶玻璃孔结构。通过扫描电子显微镜(SEM)、图像处理软件Image pro plus 6.0、DSC等分析手段研究固态Si颗粒对NCS多孔微晶玻璃内部热场、液相的影响,以及Si颗粒调控NCS多孔微晶玻璃气泡成核机制。结果表明,通过加入固态Si颗粒可以使NCS多孔微晶玻璃基础配合料内部热扩散速率提高23.5%,NCS多孔微晶玻璃内部液相产生温度降低60℃,液相产生速率增大7~8倍;在固态Si颗粒周围先产生液相,液相中的气泡分子在固态Si颗粒表面非均相成核,随着配合料温度的升高,无固态Si颗粒位置处产生新的液相,液相中气泡分子扩散至固态Si颗粒表面促进原始气泡长大或者在新液相中均相成核。展开更多
文摘Cylindrical components of in situ functionally gradient composite materials of Al-19Si-5Mg alloy were manufactured by centrifugal casting. Microstructure characteristics of the manufactured components were observed and the effects of the used process factors on these characteristics were analyzed. The results of observations shows that, in thickness, the components possess microstructures accumulating lots of Mg2Si particles and a portion of primary silicon particles in the inner layer, a little MgzSi and primary silicon particles in the outer layer, and without any Mg2Si and primary silicon particle in the middle layer. The results of the analysis indicate that the rotation rate of centrifugal casting, mould temperature, and melt pouring temperature have evidently affected the accumulation of the second phase particles. Also, the higher the centrifugal rotation rate, mould temperature, and melt pouring temperature are, the more evident in the inner layer the degree of accumulation of Mg2Si and primary silicon particles is.
基金supported by the National Natural Science Foundation of China(No 20274052).
文摘Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid （2,4-D） as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale range. The adsorbing experiments indicated that the imprinted polymer particles possessed higher affinity to 2,4-D than the non-imprinted polymer particles.
基金Sponsored by the Ministry of Science and Higher Education of the Russian Federation(Grant No.FZMU-2022-0007 (122082600014-6))the National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environment Fund(Grant No.6142910210208)the Stability Support Fund(Grant No. WDZC-HGD-2022-05)of Harbin Institute of Technology of PR China。
文摘The effect of protons(E = 100 keV,F = 5×10^(15) cm^(-2)) exposure on the diffuse reflectance spectra of the SiO_(2 )with different size particles in wavelength range from 250 to 2500 nm have been investigated.Particles were nanosphere,submicrosphere,microsphere and submacrosphere,as well as solid micro-and nanocrystals.The synthesis of the particles was carried out by the formation of silica shells and dissolution of the polystyrene core particles.The surface morphology,surface area and crystal structure of the particles have been investigated.When evaluating the changes of the solar absorptance,it was found that the radiation stability of the micro-and submacro-hollow particles is higher than that of the other nanostructured particles,except for solid microcrystals.The low radiation stability of the hollow microparticles is due to the large void inside the hollow particles where radiation defects are not formed.
基金Supported by China 863 High Technology Development Program "Study on identification and Quantitative Retriveval of the Lunar Surface Composition" (2010AA122203)
文摘The low energy particle detector （LEPD） is one of the main payloads onboard the China seismic electromagnetic satellite （CSES）. The detector is designed to ascertain space electrons （0.1–10 MeV） and protons （2–50 MeV）. It has the capability of identifying the electrons and protons, to measure the energy spectrum and the incident angle of the particles. The LEPD is made up of a silicon tracker system, a CsI （Tl） mini-calorimeter, an anti-coincidence system made by plastic scintillator, as well as electronics and a data acquisition system （DAQ）. The tracker is also a kind of E-E telescope; it consists of two layers of double-sided silicon strip detectors （DSSD）. The signals emerging from the silicon tracker can be read out by two pieces of application specific integrated circuit （ASIC）, which also can generate an event trigger for the LEPD. The functions of the DSSD system in the LEPD for charged particles were tested by 241Am @5.486 MeV α particles. The results show that the DSSD system works well, and has high performance to detect charged particles and measure the position of incident particles.
文摘针对Na_(2)O-CaO-SiO_(2)(NCS)多孔微晶玻璃内部气孔大小不同、分布不均问题,提出通过添加固态Si颗粒调控NCS多孔微晶玻璃孔结构。通过扫描电子显微镜(SEM)、图像处理软件Image pro plus 6.0、DSC等分析手段研究固态Si颗粒对NCS多孔微晶玻璃内部热场、液相的影响,以及Si颗粒调控NCS多孔微晶玻璃气泡成核机制。结果表明,通过加入固态Si颗粒可以使NCS多孔微晶玻璃基础配合料内部热扩散速率提高23.5%,NCS多孔微晶玻璃内部液相产生温度降低60℃,液相产生速率增大7~8倍;在固态Si颗粒周围先产生液相,液相中的气泡分子在固态Si颗粒表面非均相成核,随着配合料温度的升高,无固态Si颗粒位置处产生新的液相,液相中气泡分子扩散至固态Si颗粒表面促进原始气泡长大或者在新液相中均相成核。
