نتایج جستجو برای: sulfur

تعداد نتایج: 32690  

2013
Ahlert Schmidt Ingrid Erdle Hans-Peter Köst

Synechococcus, C-Phycocyanin, Sulfur Nutrition The cyanobacterium Synechococcus 6301 is able to use a lim ited number o f sulfur compounds as the only source o f sulfur supply such as sulfate, thiosulfate, thioacetic acid, mercaptoacetic acid, thioacetamide, L-cysteine and glutathione. Compounds containg thioether linkages such as methionin or S-methylcysteine and all compounds investigated so ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم پایه 1389

چکیده: مقدمه: هدف از این مطالعه مقایسه میزان mmp-1,2,8,9ومیزان timp-1,2در اشک چشم افراد مواجهه یافته با گاز خردل در جنگ ایران و عراق که دارای خشکی چشم مزمن هستند، با گروه شاهد می باشد. مواد وروشها:در این مطالعه 25 نفر از افراد مواجهه یافته با گاز خردل که دارای خشکی چشم مزمن بودند با گروهای شاهد شامل 25 نفر که دارای خشکی چشم مزمن بدون مواجهه یافته با گاز خردل و 25 نفر سالم مورد ارزیابی قرار ...

2013
Angel A. García

Elemental sulfur exists as a variety of forms in natural systems, from dissolved forms (noted as S8 (aq.)) to bulk elemental sulfur most stable as α-S8 (bulk) (but existing in at least 180 different allotropes and polymorphs). Elemental sulfur can form via a number of biotic and abiotic processes, many of which begin with S-S bonding of practically unlimited length, forming chains and rings of ...

Journal: :Environmental entomology 2012
J L Woods A J Dreves G C Fisher D G James L C Wright D H Gent

The twospotted spider mite, Tetranychus urticae Koch, is a worldwide pest of numerous agronomic and horticultural plants. Sulfur fungicides are known to induce outbreaks of this pest on several crops, although mechanisms associated with sulfur-induced mite outbreaks are largely unknown. Studies were conducted during 2007-2009 in Oregon and Washington hop yards to evaluate the effect of timing ...

2013
Sara Seager Renyu Hu William Bains

Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H2S and SO2) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative ...

Journal: :Metal ions in life sciences 2014
Larry L Barton Marie-Laure Fardeau Guy D Fauque

Sulfur is an essential element for the synthesis of cysteine, methionine, and other organo-sulfur compounds needed by living organisms. Additionally, some prokaryotes are capable of exploiting oxidation or reduction of inorganic sulfur compounds to energize cellular growth. Several anaerobic genera of Bacteria and Archaea produce hydrogen sulfide (H2S), as a result of using sulfate (SO(4)(2 -) ...

Journal: :Chemical communications 2014
Sifei Zhuo Yi Huang Cuibo Liu Huan Wang Bin Zhang

Sulfur copolymer nanowires have been reported for the first time as highly stable visible-light-active photocatalysts for photoelectrochemical water splitting depending on their size and sulfur content. The as-prepared sulfur copolymer nanowires can serve as a sulfur source and templates to create metal sulfide/copolymer heterocatalysts.

2013
Renyu Hu Sara Seager William Bains

Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H2S and SO2) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative ...

2015
Toshimasa TAKANOHASHI

Petroleum refineries utilize thermal cracking, catalytic cracking and hydrogenation processes to produce high quality oil products. Hydrodesulfurization is one of the most important methods to remove sulfur from petroleum fractions. Heavy oil contains various types of sulfur compound. The structure of the sulfur compounds affects the ease of sulfur removal1). Acyclic sulfur compounds including ...

The nutrient elements uptake in many of soils, is a problem because of high pH and plenty of calcium ions in them. Some of these elements are phosphorus and microelements. It is possible to increase absorption of these nutrient elements by addition of sulfur in soil and biological oxidation. The rate of this reaction is very slow and Thiobacillus bacteria are the most important oxidators of sul...

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