检索结果-南通市图书馆

Growth Kinetics of Nanocrystals and Nanorods by Employing Small-angle X-ray Scattering (SAXS) and Other Techniques

Journal of Materials Science & Technology 2008年第4期24卷 615-627页

作者： Kanishka BISWAS neenu varghese C.N.R.Rao Chemistry and Physics of Materials Unit DST Nanoscience Unit and CSIR Centre of Excellence in ChemistryJawaharlal Nehru Centre for Advanced Scientific ResearchJakkur P.O.Bangalore 560064India Solid State and Structural Chemistry UnitIndian Institute of ScienceBangalore 560012India Chemistry and Physics of Materials Unit DST Nanoscience Unit and CSIR Centre of Excellence in ChemistryJawaharlal Nehru Centre for Advanced Scientific ResearchJakkur P.O.Bangalore 560064India

In this article, we report the results of our detailed investigations of the growth kinetics of zero-dimensional nanocrystals as well as one-dimensional nanorods by the combined use of small angel X-ray scattering （SAXS）, transmission electron microscopy （TEM） along with other physical techniques. The study includes growth kinetics of gold nanocrystals formed by the reduction of HAuCl4 by tetrakis（hydroxymethyl） phosphonium chloride in aqueous solution, of CdSe nanocrystals formed by the reaction of cadmium stearate and selenium under solvothermal conditions, and of ZnO nanorods formed by the reaction of zinc acetate with sodium hydroxide under solvothermal conditions in the absence and presence of capping agents. The growth of gold nanocrystals does not follow the diffusion-limited Ostwald ripening, and instead follows a Sigmoidal rate curve. The heat change associated with the growth determined by isothermal titration calorimetry is about 10 kcal·mol^-1 per I nm increase in the diameter of the nanocrystals. In the case of CdSe nanocrystals also, the growth mechanism deviates from diffusion-limited growth and follows a combined model containing both diffusion and surface reaction terms. Our study of the growth kinetics of uncapped and poly（vinyl pyrollidone）（PVP）-capped ZnO nanorods has yielded interesting insights. We observe small nanocrystals next to the ZnO nanorods after a lapse of time in addition to periodic focusing and defocusing of the width of the length distribution. These observations lend support to the diffusion-limited growth model for the growth of uncapped ZnO nanorods. Accordingly, the time dependence on the length of uncapped nanorods follows the L3 law as required for diffusion-limited Ostwald ripening. The PVP-capped nanorods, however, show a time dependence, which is best described by a combination of diffusion （L^3） and surface reaction （L^2） terms.

关键词： Growth kinetics Gold nanocrystals CdSe nanocrystals ZnO nanorods Small angle X-ray scattering Transmission electron microscopy Ostwald ripening and sigmoidal growth

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Biochars produced from coconut palm biomass residues can aid regenerative agriculture by improving soil properties and plant yield in humid tropics

引用

Biochar 2020年第2期2卷 211-226页

作者： Murali Gopal Alka Gupta K.Shahul Hameed neenu Sathyaseelan T.H.Khadeejath Rajeela George V.Thomas ICAR-Central Plantation Crops Research Institute KasaragodKerala 671124India Present Address:Winsome F&D Consultant DubaiUAE Council for Food Research and Development KonniKeralaIndia

Lignin-rich recalcitrant biomass residues of coconut palms viz.(i)mature coconut husk,(ii)tender(immature or green)coconut husk(iii)coconut leaf petiole and(iv)coir-pith were successfully pyrolysed using a simple charring kiln into carbon-rich,black,light weight and porous *** alkalinity and good ash content made them fit for remediating acid *** potassium content in these biochars could help reduce the use of inorganic *** analysis showed the mass loss phases of husk and coconut leaf petiole biochars to be ***,all four biochars gave smooth curves indicating thermal stability of the *** seed germination and earthworm avoidance tests proved their potential as soil *** incubation studies with coconut biochars in graded doses,alone or in combination with coconut leaf vermicompost,increased the pH,organic carbon and potassium contents,and promoted plant-beneficial microbiota and enzyme *** studies with tender coconut husk biochar and coconut leaf vermicompost enhanced the dry weight of cowpea plants accompanied with increased arbuscular mycorrhizal sporulation and root colonization,and root nodule dry weight.A field trial resulted in higher chilli yields with tender coconut husk biochar+coconut leaf vermicompost *** results from our studies highlight the potential of pyrolysis as an innovative technology for quick recycling of highly recalcitrant coconut palm biomass residues to biochars as a local source of soil amendment to aid regenerative agriculture in humid tropics.

关键词： Coconut husks Biochar Plant-beneficial microbiota Earthworm avoidance Mycorrhizae

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：