نتایج جستجو برای: اثرکاتالیستی γ-Fe2O3

تعداد نتایج: 78174  

ژورنال: :پژوهش های کاربردی در شیمی 0
فاطمه بدلی کارشناس ارشد شیمی فیزیک، گروه شیمی، دانشگاه ارومیه، ارومیه، ایران اسماعیل عمرانی دانشجوی دکترای شیمی آلی، گروه شیمی، دانشگاه شهید بهشتی، تهران، ایران نادر نوروزی پسیان دانشیار شیمی آلی، گروه شیمی، دانشگاه ارومیه، ارومیه، ایران

کمپلکس اکسووانادیم (iv) از واکنش vo(acac)2  با شیف باز n'،n) h2l–بیس(سالیسیل آلدامیناتو) 1،3– دی آمینو پروپان) به دست آمد و با استفاده از روش های 13c-nmr، 1h-nmr،ir تجزیه عنصری و تجزیه گرمایی با روش dsc مورد بررسی قرار گرفت. داده های به دست آمده از dsc نشان داد که این کمپلکس دارای آنتالپی تخریب زیادی است. بنابراین، با توجه به این موضوع سینتیک تخریب گرمایی آن با و بدون حضور نانوذره آهن اکسی...

2017
Wensheng Ning Tianqi Wang Hongxian Chen Xiazhen Yang Yangfu Jin

The effect of Fe2O3 crystal phases on their performance in CO2 hydrogenation was studied. α-Fe2O3 crystal was prepared by precipitation method from Fe(NO3)3·9H2O and (NH4)2CO3, and γ-Fe2O3 was prepared by grinding Fe(NO3)3·9H2O and L(+)-Tartaric acid in agate mortar completely. The crystal phases of Fe2O3 influence the distribution of promoter Zn, K and Cu on catalysts. The dispersity of K on γ...

2017
Jing Hu Huiyuan Guo Junli Li Yunqiang Wang Lian Xiao Baoshan Xing

BACKGROUND Nutrient-containing nanomaterials have been developed as fertilizers to foster plant growth and agricultural yield through root applications. However, if applied through leaves, how these nanomaterials, e.g. γ-Fe2O3 nanoparticles (NPs), influence the plant growth and health are largely unknown. This study is aimed to assess the effects of foliar-applied γ-Fe2O3 NPs and their ionic co...

2016
Yassine El Mendili Jean-François Bardeau Nirina Randrianantoandro Jean-Marc Greneche Fabien Grasset

The effects of laser irradiation on γ-Fe2O3 4 ± 1 nm diameter maghemite nanocrystals synthesized by co-precipitation and dispersed into an amorphous silica matrix by sol-gel methods have been investigated as function of iron oxide mass fraction. The structural properties of γ-Fe2O3 phase were carefully examined by X-ray diffraction and transmission electron microscopy. It has been shown that γ-...

2010
Ji-Hun Yu Jai-Sung Lee Yong-Ho Choa Heinrich Hofmann

SiO2 coated γ-Fe2O3 nanocomposite powder has been successfully synthesized by chemical vapor condensation process and its feasibility on hyperthermic application was investigated in this study. The power loss of SiO2 coated γ-Fe2O3 nanocomposite powder which means the magnetic heating effect under alternative magnetic field was much higher than the single phase γ-Fe2O3 nano powder due to the ve...

Journal: :Chemosensors 2022

The gas sensitivity of semiconductor metal oxides, such as γ-Fe2O3 and SnO2, is investigated together with the synergistic effects in conjunction grapheme. Nanoparticles γ-Fe2O3, γ-Fe2O3/SnO2, γ-Fe2O3/SnO2/RGO, prepared by two-step fabrication, were assembled gas-sensing devices to assess their sensitivities; response recovery times for detection ethanol, methanol, isopropanol, formaldehyde, H2...

Journal: :Dalton transactions 2014
V Rocher J Manerova M Kinnear D J Evans M G Francesconi

A novel and simple preparation of amine-modified γ-Fe2O3 nanoparticles is described. The presence of amine groups on the surface, instead of hydroxyl groups, will allow conjugation of biologically active molecules to the iron oxide nanoparticles without the need for a size increasing silica shell. Furthermore, the outer amine-layer increases the temperature of the γ-Fe2O3 to α-Fe2O3 structural ...

Journal: :Molecules 2014
Tzong-Yuan Juang Shao-Ju Kan Yi-Yu Chen Yi-Lin Tsai Min-Guan Lin Long-Liu Lin

In this study, we synthesized water-soluble hyperbranched poly(amido acid)s (HBPAAs) featuring multiple terminal CO2H units and internal tertiary amino and amido moieties and then used them in conjunction with an in situ Fe2+/Fe3+ co-precipitation process to prepare organic/magnetic nanocarriers comprising uniformly small magnetic iron oxide nanoparticles (NP) incorporated within the globular H...

2016
Derang Cao Hao Li Lining Pan Jianan Li Xicheng Wang Panpan Jing Xiaohong Cheng Wenjie Wang Jianbo Wang Qingfang Liu

We have demonstrated the synthesis of γ-Fe2O3 nano-particles through a facile and novel calcination process in the air. There is no pH regulation, gas atmosphere, additive, centrifugation or other complicated procedures during the preparing process. A detailed formation process of the nano-particles is proposed, and DMF as a polar solvent may slower the reaction process of calcination. The stru...

2014
Michal Babič Daniel Horák Lyubov L Lukash Tetiana A Ruban Yurii N Kolomiets Svitlana P Shpylova Oksana A Grypych

Surface-modified maghemite (γ-Fe2O3) nanoparticles were obtained by using a conventional precipitation method and coated with D-mannose and poly(N,N-dimethylacrylamide). Both the initial and the modified particles were characterized by transmission electron microscopy and dynamic light scattering with regard to morphology, particle size and polydispersity. In vitro survival of human stem cells ...

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