نتایج جستجو برای: Quaternary system

تعداد نتایج: 2243786  

Aims & Backgrounds: The Quaternary period is considered as the interval of climatic oscillations (glacial and interglacial) coupled with tectonic episodes. Therefore, tectonics and climate have simultaneously governed the evolution of Quaternary alluvial fans. Unraveling the tectonic and climatic factors under varied depositional systems is therefore the fundamental issue in understanding the e...

Journal: :تحقیقات جغرافیایی 0
داود مختاری دانشگاه تبریز داود مختاری دانشگاه تبریز

â â â  parsian alluvial fan system is a part of asyab-kharabeh fluvial system that response it to quaternary climate changes is the main goal of this study. for this aim, climatic proxies and traces in alluvial fan structure were investigated base d o n four categories: aggradation and degradation phases, debris flows, size changes in deposited materials and formation of alluvial fan tufas. pri...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

2015

Introduction Pre-Quaternary paleoclimate modeling is the science of simulating climate change over the earliest 99.9% of Earth’s history using numerical models of the climate system. The record of pre-Quaternary climate documents enormous climate swings with global ice-covered and ice-free end members. A number of climate factors shaped Quaternary and pre-Quaternary paleoclimate on timescales r...

2011
Zhi-Yong Han Rui Guo Pu-Sheng Wang Dian-Feng Chen Han Xiao Liu-Zhu Gong

An asymmetric cyclization of alkynols triggered addition of azlactones catalyzed by a combined catalyst system consisting of a chiral gold phosphate and a phosphoric acid produces conformationally restricted amino acid precursors bearing vicinal quaternary stereogenic centers in high levels of stereoselectivity. 2011 Elsevier Ltd. All rights reserved. The enantioselective construction of quater...

2012
S. M. Thahab

The optical properties of InGaN/GaN laser diode based on quaternary alloys stopper and superlattice layers are numerically studied using ISE TCAD (Integrated System Engineering) simulation program. Improvements in laser optical performance have been achieved using quaternary alloy as superlattice layers in InGaN/GaN laser diodes. Lower threshold current of 18 mA and higher output power and slop...

Journal: :Protein science : a publication of the Protein Society 2004
K V Brinda Nivedita Mitra Avadhesha Surolia Saraswathi Vishveshwara

It is well known that the sequence of amino acids in proteins code for its tertiary structure. It is also known that there exists a relationship between sequence and the quaternary structure of proteins. The question addressed here is whether the nature of quaternary association can be predicted from the sequence, similar to the three-dimensional structure prediction from the sequence. The clas...

2017

Introduction Pre-Quaternary paleoclimate modeling is the science of simulating climate change over the earliest 99.9% of Earth’s history using numerical models of the climate system. The record of pre-Quaternary climate documents enormous climate swings with global ice-covered and ice-free end members. A number of climate factors shaped Quaternary and pre-Quaternary paleoclimate on timescales r...

2017

Introduction Pre-Quaternary paleoclimate modeling is the science of simulating climate change over the earliest 99.9% of Earth’s history using numerical models of the climate system. The record of pre-Quaternary climate documents enormous climate swings with global ice-covered and ice-free end members. A number of climate factors shaped Quaternary and pre-Quaternary paleoclimate on timescales r...

In oredr to reduce costs and save time for the membrane manufacturing process, it is necessary to improve the quality of membranes by modeling usage. In this study, Flory Huggins model was used to predict quaternary-system containing polyether sulfone, N-Methyl-2-pyrrolidone, water and used alkanes as an additive. Due to the solubility parameters and molar alkane volumes, the interaction parame...

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