نتایج جستجو برای: conical lattice structure made of carbon

تعداد نتایج: 21275669  

Journal: :journal of solid mechanics 0
f saljughi national iranian oil company (nioc), iran

a finite element analysis is presented for sloshing and impulsive motion of liquid-filled conical tanks during lateral anti-symmetric excitation. the performed analyses led to the development of a number of charts which can be used to identify the natural frequency, the mode shapes of conical tanks for both fundamental and the cos(θ)-modes of vibration. conical tank geometry was described with ...

BACKGROUND: The tongue, which plays a very important role in food intake by vertebrates, exhibits significant morphological variations that appear to represent adaptation to the current environmental conditions of each respective habitat. OBJECTIVES: The aim of the present investigation was to investigate lingual structure in adult budgerigar. METHODS: Tongues of 12 adult budgerigars were used ...

2001
Hendrik Willem Christiaan POSTMA Leonid Gurevich Liesbeth Venema Alberto Morpurgo Keith Williams John van Noort

Carbon nanotubes are molecules entirely made of carbon atoms. Owing to their special shape, they are extremely stiff but also very flexible. The electronic properties are determined by the exact symmetry of the nanotube lattice, resulting in either metallic or semiconducting behavior. Due to their small diameter, electronic motion is directed in the length direction of the nanotube, making them...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت معلم تهران 1376

هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...

2015
Agnieszka Dyonizy Vitaliy Kaminker Joanna Wieckowska Tomasz Krzywicki Jim Pantaleone Piotr Nowak Jerzy Maselko

BACKGROUND Biological structures grow spontaneously from a seed, using materials supplied by the environment. These structures are hierarchical, with the 'building blocks' on each level constructed from those on the lower level. To understand and model the processes that occur on many levels, and later construct them, is a difficult task. However interest in this subject is growing. It is now p...

Journal: :Physical review letters 2016
Daniel Leykam M C Rechtsman Y D Chong

We propose a class of photonic Floquet topological insulators based on staggered helical lattices and an efficient numerical method for calculating their Floquet band structure. The lattices support anomalous Floquet topological insulator phases with vanishing Chern number and tunable topological transitions. At the critical point of the topological transition, the band structure hosts a single...

پایان نامه :دانشگاه تربیت معلم - سبزوار - دانشکده ادبیات و علوم انسانی 1391

abstract this study evaluates the iranian pre-university english textbook in terms of needs, objectives, content, and methodology. the study was designed on the qualitative- quantitative survey basis using interviews and questionnaires, a researcher-made textbook evaluation checklist and a needs analysis questionnaire. the textbook evaluation questionnaire was used in this study to elicit the ...

Journal: :journal of nanostructures 2015
a. khajesarvi g. h. akbari

in the present study, nanocrystalline ni50al50-xmox (x = 0, 0.5, 1, 2.5, 5) intermetallic compound was produced through mechanical alloying of nickel, aluminum, and molybdenum powders. alni compounds with good and attractive properties such as high melting point, high strength to weight ratio and high corrosion resistance especially at high temperatures have attracted the attention of many rese...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان - دانشکده ادبیات و علوم انسانی 1392

abstract the present study investigated the effects of task types and involvement load hypothesis on incidental learning of 10 target words (tws) in junior high schools (jhss) in givi, ardabil. the tasks deployed in this study were two input-based tasks (reading plus dictionary use with an involvement index of 3, and reading plus gap-fill task with an involvement index of 2), and one output-ba...

Photonic crystal ring resonators (PCRRs) are traditional structures fordesigning optical channel drop filters. In this paper, Photonic crystal channel drop filter(CDFs) with a new configuration of ring resonator is presented. The structure is made ofa square lattice of silicon rods with the refractive index nsi=3. 4 which are perforated inair with refractive index nair=1. Calculations of band s...

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