نتایج جستجو برای: acidity

تعداد نتایج: 9976  

Journal: :Chemical communications 2014
John Gräsvik Jason P Hallett Trang Quynh To Tom Welton

Introduced here is a quick, simple, robust method to measure acidity in ionic liquid (IL) systems by the use of the NMR-probe mesityl oxide. Acidity corresponding to a Hammett acidity of -1 to -9 can be measured reliably using this technique, a range that vastly exceeds that of any single UV-vis probe.

2011
Anatolij Osipov Vladislav Minin

Contents 1. Introduction 2. Soil acidity and its indices 2.1. Actual acidity. 2.2. Potential acidity. 2.3. Cation (positive ion) exchange capacity and saturation with bases. 3. Natural reasons for increasing soil acidification 3.1. Leaching regime. 3.2. Soil-forming rocks and plants. 3.3. The distribution of acid soils. 4. The reasons for anthropogenic acidification of soils. The phenomenon of ...

2013
Benjamin AJ Reddi

Commercial 0.9% saline solution for infusion has a pH around 5.5. There are many reasons for this acidity, some of them still obscure. It is also true that infusion of normal saline can lead to metabolic acidaemia, yet the link between the acidity of saline solution and the acidaemia it can engender is not straightforward. This commentary draws together the known and putative sources of acidity...

2016
Wenyu Huang Ying Wang Yuan Chun Jia Rong Xia Jian Hua Zhu Wen Yu Huang

Journal: :Angewandte Chemie 2008
Yun Zhang Fook S Tham John F Nixon Charlotte Taylor Jennifer C Green Christopher A Reed

2005
R. Uchida

Soil pH, soil acidity, and their effects on plants The pH scale, ranging from 0 to 14, is used to indicate acidity and alkalinity. pH is a measure of the concentration of hydrogen ions (symbol = H) in the water contained in the soil. A pH of 7.0 is neutral, values below 7 are acidic, and those above 7 are alkaline (basic). The lower the pH, the more acid the soil. Each unit pH drop indicates te...

2009
A. Pagani

Soil acidity can affect plant growth directly and indirectly by affecting the plantavailability of nutrients, levels of phytotoxic elements, and microbial activity. Soils may become acidic in the long term as a result of several natural processes. In the short term, however, soil acidity develops mainly due to application of N fertilizers or manure, primarily those having high concentrations of...

Journal: :Plant physiology 1951
R A Steinberg

The influence of acidity on the growth of plants in water-culture has been studied by investigators with varying results. Many have reported a beneficial effect of moderate acidity; whereas others have succeeded in demonstrating equally good growth in solutions of widely different hydrogen-ion concentration. Citations to the literature can be found in a paper by the writer (5) dealing with the ...

2015
Shichang Deng Xiang Li Yi Niu Shuai Zhu Yan Jin Shijiang Deng Jingyuan Chen Yang Liu Chi He Tao Yin Zhiyong Yang Jing Tao Jiongxin Xiong Heshui Wu Chunyou Wang Gang Zhao

Recent evidences suggest that the acidic microenvironment might facilitate epithelial mesenchymal transition (EMT) of tumor cells, while the effects of acidity on EMT of pancreatic cancer (PC) remain undefined. The present study demonstrated that acidity suppressed miR-652 expression, which further promoted EMT process by absenting inhibition on the transcriptional factor ZEB1 expression. At fi...

Journal: :Gut 1973
S Nundy J H Baron

Hollander's insulin test was evaluated by performing successively partial denervation of the parietal cell area, highly selective, selective, and truncal vagotomy operations on three dogs. The rise in acidity, the timing of the highest rise in acidity, and the rise in acid output were examined. The mean rise in acidity (m-equiv/l) before vagotomy (106 +/- SE11, 120 +/- 23, 60 +/- 16) did not di...

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