نتایج جستجو برای: boron

تعداد نتایج: 18025  

Journal: :Chemical reviews 2010
Nadia Balucani Fangtong Zhang Ralf I Kaiser

The chemical reactivity of atomic boron, B(Pj), with inorganic and organic molecules is a fascinating subject of research from the experimental1-35 and theoretical viewpoints.29,30,36-46 Atomic boron resides in the same row as carbon, nitrogen, and oxygen.47 Although the reaction dynamics and kinetics of the latter elements (C, N, O) have been studied in depth,48-53 an investigation of elementa...

Journal: :Environmental Health Perspectives 1994
J G Penland

Although the trace element boron has yet to be recognized as an essential nutrient for humans, recent data from animal and human studies suggest that boron may be important for mineral metabolism and membrane function. To investigate further the functional role of boron, brain electrophysiology and cognitive performance were assessed in response to dietary manipulation of boron (approximately 0...

Journal: :Chemical science 2015
Frédéric A Perras William C Ewing Theresa Dellermann Julian Böhnke Stefan Ullrich Thomas Schäfer Holger Braunschweig David L Bryce

There is currently tremendous interest in the previously documented example of a stable species exhibiting a boron-boron triple bond (Science, 2012, 336, 1420). Notably, it has recently been stated using arguments based on force constants that this diboryne may not, in reality, feature a boron-boron triple bond. Here, we use advanced solid-state NMR and computational methodology in order to dir...

2005
Anastassia N. Alexandrova Alexander I. Boldyrev Hua-Jin Zhai Lai-Sheng Wang

Small boron clusters as individual species in the gas phase are reviewed. While the family of known boron compounds is rich and diverse, a large body of hitherto unknown chemistry of boron has been recently identified. Free boron clusters have been recently characterized using photoelectron spectroscopy and ab initio calculations, which have established the planar or quasi-planar shapes of smal...

Journal: :journal of agricultural science and technology 0
m. brdar-jokanović institute of field and vegetable crops, maksima gorkog 30, 21000 novi sad, serbia. m. zorić institute of field and vegetable crops, maksima gorkog 30, 21000 novi sad, serbia. a. kondić-špika institute of field and vegetable crops, maksima gorkog 30, 21000 novi sad, serbia. i. maksimović faculty of agriculture, university of novi sad, trg dositeja obradovića 8, 21000 novi sad, serbia. b. kobiljski biogranum, research and development center, toplice milana 20, 21000 novi sad, serbia. m. kraljević-balalić faculty of agriculture, university of novi sad, trg dositeja obradovića 8, 21000 novi sad, serbia.

this study was aimed to assess the effects of excess boron on 59 genetically divergent wheat accessions and to identify those with high and stable yields under a range of soil boron concentrations. the second aim was to test the applicability of a laboratory technique performed at juvenile stages of development in estimating field boron tolerance. the study comprised a control and three boron t...

2004
H. A. W. El Mubarek J. M Bonar G. D. Dilliway P. Ashburn A. F. Willoughby P. L. F. Hemment

This paper investigates how the thermal diffusion of boron in silicon is influenced by a high energy fluorine implant with a dose in the range 531014–2.331015 cm−2. Secondary Ion Mass Spectroscopy (SIMS) profiles of boron marker layers are presented for different fluorine doses and compared with fluorine profiles to establish the conditions under which thermal boron diffusion is suppressed. The...

Journal: :Environmental Health Perspectives 1994
R E Newnham

Since 1963, evidence has accumulated that suggests boron is a safe and effective treatment for some forms of arthritis. The initial evidence was that boron supplementation alleviated arthritic pain and discomfort of the author. This was followed by findings from numerous other observations epidemiologic and controlled animal and human experiments. These findings included a) analytical evidence ...

2012
Richard J. Hull

As we examine the role of micronutrients in turfgrass nutrition, we enter murky waters when we consider the functions of boron. There is a scarcity of specific research on turfgrasses, so there remain questions about its roles. Since this subject has been reviewed recently (Blevins and Lukaszewski 1998), we interpret the current state of knowledge about boron's importance to turfgrass managemen...

Journal: :Zeitschrift fur Lebensmittel-Untersuchung und -Forschung 1995
Y Vetter

The boron contents of 68 edible common macrofungi of Hungary were analysed. The average boron content of the examples was 11.74 mg/kg dry mass, this is higher than the average value of green plants of Hungary (7.4 mg/kg dry mass). Although the highest boron contents were found in the examples from woods near Budapest, the differences between the various sites are not significant. It seems that ...

2001
E. J. Stewart M. S. Carroll James C. Sturm

Boron penetration through thin gate oxides in p-channel MOSFETs with heavily boron-doped gates causes undesirable positive threshold voltage shifts. P-channel MOSFETs with polycrystalline Si1 x yGexCy gate layers at the gate-oxide interface show substantially reduced boron penetration and increased threshold voltage stability compared to devices with all poly Si gates or with poly Si1 xGex gate...

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