纳米晶体二氧化钛非水体系合成和光催化性能   总被引：1，自引：0，他引：1  

陈小泉  张春华 《衡阳师范学院学报》2001,22(3):25-30

钛酸丁酯和乙酐在低于100℃非水状态下生成非晶钛氧聚合物，经焙烧得到纳米二氧化钛晶体，焙烧失重46．55％，在314℃～389℃之间失去表面有机基团，389℃～405℃之间转化为锐钛矿型晶体。XRD和TEM研究了晶体颗粒的袁征。用苯胶的光催化降解评价了非水合成的纳米晶体二氧化钛的光催化活性。  相似文献   

γ-Fe203和Fe纳米微粒的制备及相组成     

祝玉华唐贵德  王贺清孙云鹏 《唐山师范学院学报》2007,29(5):7-9

用共沉淀法制备γ-Fe203和Fe纳米微粒，用X-射线衍射和TEM研究其相结构和形貌，并对影响相组成的因素进行了分析。  相似文献   

纳米微粒的制备方法及其进展   总被引：1，自引：0，他引：1  

陈玉成 《宁德师专学报(自然科学版)》2001,13(1):12-15

综述目前纳米微粒的各种制备方法 ,比较和评述了每种方法的特点 ,以期这一新材料能得以更为深入地研究和更广泛地应用  相似文献   

Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid   总被引：1，自引：0，他引：1  

Cai W  Xu Y  Chen JZ  Huang SR  Lu ZY  Wang ZK 《Journal of Zhejiang University. Science. B》2005,6(9):892-896

Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA)content of the VSMC were assayed. Results: 1×10-9, 1×10-8, 1×10-7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%,and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P＜0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P＜0.05), 29.6% (P＜0.01), and 48.9% (P＜0.01)respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P＜0.01) respectively, in the 1×10-7mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion.  相似文献   

神奇的土颗粒与土力学实验教学改革     

林伟岸  詹良通  王顺玉 《实验室研究与探索》2011,30(9)

基于土力学实验特点及教学现状的分析研究,重点探讨了目前实验内容设置和实验教学模式.针对其不足对土力学实验教学进行改革,包括更新实验内容,改革教学模式,以教学演示仪器及土颗粒神奇现象等方式吸引学生,从而提高了土力学实验教学水平,激发学生兴趣,培养了学生创新能力和科研素质.  相似文献   

Equatorial aurora: the aurora-like airglow in the negative magnetic anomaly     

Fei He  Yong Wei  Weixing Wan 《国家科学评论(英文版)》2020,7(10):1606

The most fantastic optical phenomena in the Earth''s upper atmosphere are the auroras. They are highly informative indicators of solar activity, geomagnetic activity, upper atmospheric structures and dynamics, and magnetospheric energetic particles. An area where the geomagnetic field differs significantly from the expected symmetric dipole, such as at the South Atlantic Anomaly, where the magnetic field intensity is low, gives rise to stronger precipitation of energetic particles into the upper atmosphere. Impact excitation and the subsequent airglow emissions exhibit aurora-like dynamic signatures. Nomenclatures of nonpolar aurora or equatorial auroras are similar to those used with the polar auroras owing to their similar excitation mechanisms. This paper provides an overview of the knowledge and the challenges concerning auroral activity at the South Atlantic Anomaly, or more generally, at the negative magnetic anomaly. We emphasize systematic investigation of the equatorial auroras to reveal the temporal and spatial evolution of the magnetic anomaly and the behaviour of energetic particles in near-Earth space.  相似文献   

纳米碳酸锶的制备技术探讨     

杜婕 《贵阳金筑大学学报》2011,(3):63-68

当前形势下,我国部分单位已经进行了纳米碳酸锶的制备研究,并巳取得一定成绩。纳米材料的合理制备是纳米碳酸锶的应用基础,制备方法按照物料的状态可分为三种：固相法、气相法和液相法,其中尤以液相化学法最为普遍。在考察了制备条件,如反应的PH值、辅助剂用量对产物的影响。获得了较佳制备条件。应用透射电子显微镜对碳酸锶的形貌及粒径进行表征。结果显示。制备出由粒径为25nm左右的碳酸锶纳米粒子组装成的纳米棒。  相似文献   

凝胶颗粒通过孔喉能力的物理实验研究     

周小金  钱银磊  曾宪举 《茂名学院学报》2014,(6):75-78

通过岩心流动实验能够有效地研究凝胶体系在一定压差条件下的封堵情况,从而为现场调剖堵水提高科学可靠的实验依据。文章首先论述了转变压力的测试装置与测试原理,然后介绍了凝胶颗粒通过孔喉能力的实验准备及实验步骤,进而从不同粒径、不同矿化度、不同膨胀时间这三个方面分析了转向压力的确定。实验结果表明：凝胶颗粒在孔吼中具有较好的流动能力。  相似文献   

现代汉语句末语气词研究     

倪宇 《鸡西大学学报》2013,(7):140-141

在前人研究的基础上,对现代汉语句末语气词的来源、称谓、界定、分类、语气意义、语用功能以及连用等方面进行了考察,通过替换、对比等方法,分析语料,以期进一步概括句末语气词的特点及其功能。  相似文献   

自由基与肺癌发病机制     

刘宏 《雁北师范学院学报》2008,24(5)

肺癌是严重影响人类健康的疾病,其发病机制目前尚未阐明.自由基医学是近年来兴起的一门交叉学科,本文对自由基在吸烟、职业烟尘微粒、金属离子、石英、石棉等理化因素致肺癌过程中的发病机制进行探讨.  相似文献