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高纯微晶状碳酸锰的研制 被引量:10
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作者 李绪福 《无机盐工业》 CAS 北大核心 1991年第4期5-9,43,共6页
本文介绍作者研制出一种高纯碳酸锰产品制作方法,并对该法原理、工艺条件、产品质量、技术经济效果作报道与分析。文中还进一步介绍产品的特异高纯微细化、高稳定性、强活性、强离子交换能力及高氧化性等性能。
关键词 碳酸锰 微晶状 制备
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一种棒状纳米微晶纤维素的物性研究 被引量:33
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作者 李小芳 丁恩勇 黎国康 《纤维素科学与技术》 CAS CSCD 2001年第2期29-36,共8页
通过X -射线衍射、透射电镜 (TEM)、激光光散射、示差扫描量热分析 (DSC)、热重分析 (TGA)以及红外光谱等分析手段 ,研究了一种具有纳米尺寸的棒状微晶纤维素的物理化学性质 ,着重研究了它在不同温度下的热行为。结果表明 ,由于粒径及... 通过X -射线衍射、透射电镜 (TEM)、激光光散射、示差扫描量热分析 (DSC)、热重分析 (TGA)以及红外光谱等分析手段 ,研究了一种具有纳米尺寸的棒状微晶纤维素的物理化学性质 ,着重研究了它在不同温度下的热行为。结果表明 ,由于粒径及比表面积的变化 ,这种棒状微晶纤维素的热行为与天然纤维素以及经过DMSO前处理的纤维素相比较 。 展开更多
关键词 纳米微晶纤维素 热行为 物性 X-射线衍射 透射电镜
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水热合成法制备杯状氧化锌微晶及其光学性质研究 被引量:5
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作者 骆英民 支壮志 +1 位作者 葛贝尔 李百芳 《功能材料》 EI CAS CSCD 北大核心 2011年第2期302-304,共3页
以Zn(CH3COO)2.2H2O为源反应物,采用水热合成反应法成功地制备了杯状的氧化锌微晶粉体材料。X射线衍射(XRD)谱的结果表明获得了典型的六方结构晶体。扫描电子显微镜(SEM)照片观测到杯状的氧化锌微晶,并且单个微晶互相结合形成对称结构... 以Zn(CH3COO)2.2H2O为源反应物,采用水热合成反应法成功地制备了杯状的氧化锌微晶粉体材料。X射线衍射(XRD)谱的结果表明获得了典型的六方结构晶体。扫描电子显微镜(SEM)照片观测到杯状的氧化锌微晶,并且单个微晶互相结合形成对称结构。实验发现,水热时间影响着晶体的形貌,对其结构变化机制进行了探讨。同时,通过室温光致发光(PL)光谱,对其光学性质进行了研究。 展开更多
关键词 氧化锌微晶 水热合成方法 光致发光 制备
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棒状纳米微晶纤维素的热降解行为(英文) 被引量:2
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作者 程镕时 王能 +1 位作者 丁恩勇 薛锋 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2007年第10期91-98,共8页
文中对水解制备得到的纳米微晶纤维素采用了两种不同的处理方法以提高其热稳定性:于60℃下反复加热洗涤以减少其硫酸氢根含量或加入NaOH中和表面的硫酸氢根.研究表明:这两种方法都可以有效提高纳米微晶纤维素的热稳定性.与普通纤维素在... 文中对水解制备得到的纳米微晶纤维素采用了两种不同的处理方法以提高其热稳定性:于60℃下反复加热洗涤以减少其硫酸氢根含量或加入NaOH中和表面的硫酸氢根.研究表明:这两种方法都可以有效提高纳米微晶纤维素的热稳定性.与普通纤维素在热降解过程中只形成一个主要裂解区间不同,所有纳米微晶纤维素样品不仅存在主要裂解区间,而且在高温区域( >400℃)还存在一个明显的第二裂解区间.同时所有纳米微晶纤维素样品最终生成的焦炭产量很相近(3.5% ~5.0%).这说明当纤维素颗粒的粒径小至纳米尺寸时,外部催化剂的存在只是改变了其热降解的途径,但其整体热降解行为和最终的焦炭产量受其纳米颗粒特性所主导.文中还利用分峰拟合的方法表明在纳米微晶纤维素的主要裂解区间存在两个平行的竞争反应. 展开更多
关键词 纳米微晶纤维素 热降解 炭化 硫酸
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PbS棒状微晶的水热合成和表征
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作者 池泉 许露 郎迪 《中南民族大学学报(自然科学版)》 CAS 2012年第4期32-35,共4页
以L-半胱氨酸为硫源,水和乙醇混合溶剂为介质,用水热法制备了PbS棒状微晶.结合透射电镜、X-射线衍射、X-射线光电子能谱分析等手段,对PbS微晶进行了表征,探讨了原料比例、反应温度、时间和pH值等因素对所生成PbS形貌的影响和晶体生长的... 以L-半胱氨酸为硫源,水和乙醇混合溶剂为介质,用水热法制备了PbS棒状微晶.结合透射电镜、X-射线衍射、X-射线光电子能谱分析等手段,对PbS微晶进行了表征,探讨了原料比例、反应温度、时间和pH值等因素对所生成PbS形貌的影响和晶体生长的机制.结果表明:在120℃、碱性条件下,硫较铅摩尔比略过量时,可获得结晶较好且均一的PbS棒状微晶. 展开更多
关键词 硫化铅 微晶 L-半胱氨酸 水热法
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单分散g-C_3N_4量子点修饰一维棒状BiPO_4微晶的合成及其对光催化活性增强机理(英文)
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作者 王丹军 申会东 +2 位作者 郭莉 岳林林 付峰 《无机化学学报》 SCIE CAS CSCD 北大核心 2016年第7期1246-1254,共9页
利用水热法合成了一维棒状BiPO_4微晶,在此基础上采用浸渍一焙烧法进行g-C_3N_4量子点表面修饰获得新颖的g-C_3N_4/BiPO_4异质结。借助X射线衍射(XRD)、场发射扫描电镜(PE-SEM)、透射电镜(HRTEM)、能谱(EDS)、紫外-可见漫反射(UV-VisDRS... 利用水热法合成了一维棒状BiPO_4微晶,在此基础上采用浸渍一焙烧法进行g-C_3N_4量子点表面修饰获得新颖的g-C_3N_4/BiPO_4异质结。借助X射线衍射(XRD)、场发射扫描电镜(PE-SEM)、透射电镜(HRTEM)、能谱(EDS)、紫外-可见漫反射(UV-VisDRS)等测试手段对所得样品的相组成、形貌和谱学特征进行了表征。选择罗丹明B(RhB)和苯酚作为模型污染物研究了所得在可见光下的催化活性。结果表明,样品16%(ω/ωg-C_3N_4BiPO_4对RhB降解的速率常数分別是纯g-C_3N_4和BiPO_4的4.6倍和15倍。g-C_3N_4量子点与BiPO_4之间形成异质结,抑制了光生电子-空穴对的复合,从而提高了催化剂的活性。自由基捕获实验进一步表明,超氧负离子自由基(·O_2^-)是催化降解RhB和苯酚的主要活性物种。 展开更多
关键词 一维棒BiPO4微晶 g-C3N.量子点
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微波水热合成NaLa(MoO_4)_2:Eu^(3+)微晶及其发光性能 被引量:2
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作者 伍宏明 陈虎 +2 位作者 刘云飞 吕忆农 洪慧敏 《南京工业大学学报(自然科学版)》 CAS 北大核心 2015年第3期41-45,共5页
采用微波水热法合成形貌规整、尺寸均一的短棒状和树枝状NaLa(MoO4)2:Eu3+微晶。研究反应温度、反应物浓度和反应时间对产物形貌的影响。结果表明:在反应物浓度为10 mmol/L条件下,当反应温度为100℃时,产物为纳米片状结构;反应温度为15... 采用微波水热法合成形貌规整、尺寸均一的短棒状和树枝状NaLa(MoO4)2:Eu3+微晶。研究反应温度、反应物浓度和反应时间对产物形貌的影响。结果表明:在反应物浓度为10 mmol/L条件下,当反应温度为100℃时,产物为纳米片状结构;反应温度为150℃时,得到长约5μm、直径约500 nm的棒状结构产物;当反应物浓度为40mmol/L,反应温度为150℃时,产物为树枝状结构。荧光性能分析表明,棒状和树枝状微晶在464 nm蓝光有效激发下,均发射出614 nm红光,对应于Eu3+的5D0→7F2跃迁。棒状晶体的发光强度约为树枝状的10倍,这是由于棒状晶体较强的激发强度引起的。 展开更多
关键词 微波水热 微晶 NaLa(MoO4)2∶Eu3+ 荧光粉
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Effects of stress state on texture and microstructure in cold drawing-bulging of CP-Ti sheet 被引量:3
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作者 李宏伟 张下陆 +1 位作者 陈甲元 李金山 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期23-31,共9页
Three different stress states of the combination of tensile(t) stress and compressive(c) stress,t t,t c and t c c,exist in the deformed commercially pure titanium(CP-Ti) sheet during cold drawing-bulging.The tex... Three different stress states of the combination of tensile(t) stress and compressive(c) stress,t t,t c and t c c,exist in the deformed commercially pure titanium(CP-Ti) sheet during cold drawing-bulging.The textures and microstructures in the different stress state regions were investigated by means of XRD and TEM analysis.Similar development of texture and microstructure is achieved with less thickness strain under multiaxial stresses in drawing-bulging than in cold rolling.The results show that texture and microstructure are much sensitive to multiaxial stresses.Twinning is more easily activated under compressive stress than tensile stress.Prism a slip is heavily affected by tensile stress,resulting in a remarkable change of the intensity of(0°,35°,0°) texture,while pyramidal c+a slip,forming(20°,35°,30°) texture,weakens with the increase of thickness strain in spite of stress state. 展开更多
关键词 titanium alloy TEXTURE twinning MICROSTRUCTURE DRAWING stress state cold rolling drawing-bulging
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Synthesis,characterization and photocatalytic performance of rod-shaped Pt/PbWO_4 composite microcrystals 被引量:6
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作者 余长林 白羽 +3 位作者 何洪波 范文宏 朱丽华 周晚琴 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2178-2185,共8页
Rod-shaped PbW O4 microcrystals of length 1 μm were fabricated by a hydrothermal route and subsequent calcination. Pt nanoparticles(NPs) of different contents(0.5 wt%,1 wt% and 2 wt%) were subsequently deposited ... Rod-shaped PbW O4 microcrystals of length 1 μm were fabricated by a hydrothermal route and subsequent calcination. Pt nanoparticles(NPs) of different contents(0.5 wt%,1 wt% and 2 wt%) were subsequently deposited on the PbW O4 microcrystals,producing robust Pt/PbW O4 composite microcrystals. The PbW O4 microcrystals and Pt/PbW O4 photocatalysts were characterized by X-ray diffraction,N2 sorption measurements,scanning electron microscopy,transmission electron microscopy,and X-ray photoelectron,photoluminescence,Fourier-transform infrared,and ultraviolet-visible diffuse reflectance spectroscopies. The photocatalytic performances of the catalysts were evaluated by the consecutive photocatalytic degradation of acid orange II dye. The Pt/PbW O4 composite microcrystals exhibited high photocatalytic activity and stability. The deposition of Pt NPs produced surface plasmon resonance(SPR),which induced a large visible light absorption. A Pt NP content of 1-2 wt% resulted in an ~2 times increase in photocatalytic activity,compared with the activity of Pt/PbW O4. The crystal structure and high crystallinity of PbW O4 resulted in its favorable photocatalytic property,and the SPR effect of the Pt NPs promoted visible light harvesting. The Pt NPs also enhanced the separation of photo-generated electrons and holes,which further promoted the photocatalytic reaction. 展开更多
关键词 Rod-shaped Lead tungstate microcrystals Platium nanoparticles Photocatalytic activity Photocatalytic stability Surface plasma Electron-hole separation
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Combined effects of ECAP and subsequent heating parameters on semi-solid microstructure of 7075 aluminum alloy 被引量:6
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作者 Ramin MESHKABADI Ghader FARAJI +1 位作者 Akbar JAVDANI Vahid POUYAFAR 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第12期3091-3101,共11页
The combined effects of equal channel angular pressing (ECAP) and subsequent heating to a semi-solid temperature on the microstructural characteristics of the 7075 aluminum alloy were investigated. The microstructure ... The combined effects of equal channel angular pressing (ECAP) and subsequent heating to a semi-solid temperature on the microstructural characteristics of the 7075 aluminum alloy were investigated. The microstructure is influenced by several parameters including the number of ECAP passes, ECAP route, consequent heating temperature, and holding time. The effects of these parameters on the microstructural characteristics including grain size and shape factor of the 7075 aluminum alloy were studied using experimental tests and Taguchi method. The results indicate that five-pass ECAP in route BA and subsequent isothermal holding at 630 °C for 15 min are more appropriate for achieving a semi-solid microstructure. The processing route and holding time have the highest impact on the grain size while the number of ECAP passes and heating temperature have the least impact on the grain size. Meanwhile, the shape factor is significantly influenced by the processing route, holding time and heating temperature while it is less influenced by the number of ECAP passes. 展开更多
关键词 7075 aluminum alloy equal channel angular pressing semi-solid microstructure grain size shape factor
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NB122型低汽气比高变催化剂的性能研究
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作者 魏士新 《化学工业与工程技术》 CAS 2012年第2期48-52,共5页
研究了NB122型低汽气比高变催化剂的物理性能、还原性能和催化性能,剖析了催化剂微观结构与催化剂性能之间的关系,指出独特的棒状微晶结构是NB122型催化剂良好的强度、活性和稳定性的基础。
关键词 高温变换 催化剂 微晶 低汽气比
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Study on Titanium Nitride Film Modified for Intraocular Lens
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作者 ZHANG Bai-ming GU Han-qing 《Chinese Journal of Biomedical Engineering(English Edition)》 2009年第4期171-177,184,共8页
Objective:To study the characteristics of the intraocular lens using ion beam sputtering depositing titanium nitride thin film on the intraocular lens(IOLs).Methods:To deposite titanium nitride thin film on the top of... Objective:To study the characteristics of the intraocular lens using ion beam sputtering depositing titanium nitride thin film on the intraocular lens(IOLs).Methods:To deposite titanium nitride thin film on the top of intraocular lens by ion beam sputtering depositing.We analyzed the surface morphology of intraocular lens through SEM and AFM.We detected intraocular lens resolution through the measurement of intraocular lens.Biocompatibility of intraocular lens is preliminary evaluated in this test.Results:The surface morphology of intraocular lens material was not changed,and was in line with the requirements of smoothness.Resolution was in line with national requirements.Unmodified and modified IOLs's cytotoxicity were 1 and 0.6 grade respectively.Hemolytic rates of modified and unmodified were both less than 5%.Conclusion:Ion beam sputtering deposition of objects didn't only affect the surface morphology and the basic optical performance,but also can enhance the biocompatibility of intraocular lens.Ion beam sputtering deposition technique has provided new methods for the surface modification of IOLs and PMMA materials. 展开更多
关键词 titanium nitride intraocular lens surface modification RESOLUTION BIOCOMPATIBILITY
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Changes in gap junctional intercellular communication in rabbits lens epithelial cells induced by low power density microwave radiation
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作者 叶娟 姚克 +1 位作者 曾群力 鲁德强 《Chinese Medical Journal》 SCIE CAS CSCD 2002年第12期1873-1876,154,共4页
OBJECTIVE: To demonstrate the changes in gap junctional intercellular communication (GJIC) mediated by low power density microwave radiation in rabbits lens epithelial cells (LECs) and its mechanisms. METHODS: Rabbits... OBJECTIVE: To demonstrate the changes in gap junctional intercellular communication (GJIC) mediated by low power density microwave radiation in rabbits lens epithelial cells (LECs) and its mechanisms. METHODS: Rabbits' eyes were exposed to 5 mW/cm(2) and 10 mW/cm(2) power densities of microwave radiation for 3 hours. The fluorescence-recovery-after-photobleaching (FRAP) method was used to determine the GJIC. The localization and function of connexin 43 in LECs was detected by laser scanning confocal microscopy. RESULTS: The GJIC of rabbits LECs was inhibited by microwave radiation especially in the 10 mW/cm(2) irradiated samples. A decrease in connexin 43-positive staining was seen in 5 mW/cm(2) x 3 h treated LECs. Intracellular space accumulation and cytoplasmic internalization were clearly demonstrated in 10 mW/cm(2) group. CONCLUSIONS: Low power densities microwave radiation (5 mW/cm(2) and 10 mW/cm(2)) induces damage to connexin 43 and inhibits the GJIC of rabbits LECs. These changes result in an osmotic imbalance within the lens and induce early cataract. 5 mW/cm(2) or 10 mW/cm(2) microwave radiation is cataractogenic. 展开更多
关键词 ANIMALS CATARACT Cell Communication Connexin 43 Epithelial Cells Fluorescent Antibody Technique Indirect Gap Junctions Lens Crystalline Microwaves RABBITS
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Rutile TiO2 Microspheres with Exposed Nano-Acicular Single Crystals for Dye-Sensitized Solar Cells 被引量:5
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作者 Haimin Zhang Hua Yu +5 位作者 Yanhe Han Porun Liu Shanqing Zhang Peng Wang Yibing Cheng Huijun Zhao 《Nano Research》 SCIE EI CAS CSCD 2011年第10期938-947,共10页
Uniquely structured rutile TiO2 microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method. After calcination at 450 ℃ for 2 h, the futile TiO2 microsp... Uniquely structured rutile TiO2 microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method. After calcination at 450 ℃ for 2 h, the futile TiO2 microspheres with a high surface area of 132 m2/g have been utilized as a light harvesting enhancement material for dye-sensitized solar cells (DSSCs). The resultant DSSCs exhibit an overall light conversion efficiency of 8.41% for TiO2 photoanodes made of futile TiO2 microspheres and anatase TiO, nanoparticles (mass ratio of 1:1), significantly higher than that of pure anatase TiO2 nanoparticle photoanodes of similar thickness (6.74%). Such a significant improvement in performance can be attributed to the enhanced light harvesting capability and synergetic electron transfer effect. This is because the photoanodes made of futile TiO2 microsphere possess high refractive index which improves the light utilisation efficiency, suitable microsphere core sizes (450-800 nm) to effectively scatter visible light, high surface area for dye loading, and synergetic electron transfer effects between nanoparticulate anatase and nano-acicular futile single crystals phases giving high electron collection efficiency. 展开更多
关键词 High refractive index rutile TiO2 microspheres acicular single crystals synergetic effect dye-sensitized solarcells (DSSCs)
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Te-seeded growth of few-quintuple layer Bi2Te3 nanoplates 被引量:2
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作者 Yanyuan Zhao Maria de la Mata +6 位作者 Richard L. J. Qiu Jun Zhang Xinglin wen Cesar Magen Xuan P. A. Gao Jordi Arbiol Qihua Xiong 《Nano Research》 SCIE EI CAS CSCD 2014年第9期1243-1253,共11页
We report on a Te-seeded epitaxial growth of ultrathin Bi2Te3 nanoplates (down to three quintuple layers (QL)) with large planar sizes (up to tens of micrometers) through vapor transport. Optical contrast has be... We report on a Te-seeded epitaxial growth of ultrathin Bi2Te3 nanoplates (down to three quintuple layers (QL)) with large planar sizes (up to tens of micrometers) through vapor transport. Optical contrast has been systematically investigated for the as-grown Bi2Te3 nanoplates on the SiO2/Si substrates, experimentally and computationally. The high and distinct optical contrast provides a fast and convenient method for the thickness determination of few-QL Bi2Te3 nanoplates. By aberration-corrected scanning transmission electron microscopy, a hexagonal crystalline structure has been identified for the Te seeds, which form naturally during the growth process and initiate an epitaxial growth of the rhombohedral- structured Bi2Te3 nanoplates. The epitaxial relationship between Te and Bi2T% is identified to be perfect along both in-plane and out-of-plane directions of the layered nanoplate. Similar growth mechanism might be expected for other bismuth chalcogenide layered materials. 展开更多
关键词 Te nucleation seed epitaxial growth BI2TE3 few-quintuple layer TEM cross-section optical contrast
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