Results 261 to 270 of about 32,992 (301)

Imaging of Humic Substance Macromolecular Structures in Water and Soils

Science, 1999
Humic substances (HSs) are the natural organic polyelectrolytes formed from the biochemical weathering of plant and animal remains. Their macromolecular structure and chemistry determine their role in biogeochemical processes. In situ spectromicroscopic evidence showed that the HS macromolecular structures (size and shape) vary as a function of HS ...
, Myneni, , Brown, , Martinez, , Meyer-Ilse   +3 more
openaire   +2 more sources

On the mechanism of collapse of monolayers of macromolecular substances: poly(l, d, and dl)alanine

Journal of Colloid and Interface Science, 1981
Abstract The collapse process of monolayers of poly( l , d , dl )alanine has been studied at the air—water interface, and on substrates containing Ca2+, Na+, and K+. It is demonstrated that the collapse process occurs in two stages. The first, attributable to a process of nucleation, is related to the detachment of the polymeric chains from the ...
GABRIELLI, GABRIELLA, BAGLIONI, PIERO, FERRONI, ENZO   +2 more
openaire   +1 more source

The interrelationship among bradykinin, various vasoactive substances, and macromolecular permeability in the canine forelimb

Microvascular Research, 1980
Abstract Bradykinin (0.8 μg base/min) infused locally intraarterially into canine forelimbs perfused at constant inflow causes marked increases in lymph flow rate and lymph total protein concentration. This same dose of bradykinin infused locally intraarterially for 60 min into forelimbs perfused at constant inflow with vasopressin (0.8 P.U./min) or ...
R M, Raymond, B S, Jandhyala, G J, Grega
openaire   +2 more sources

MACROMOLECULAR PROPERTIES OF SOIL HUMIC SUBSTANCES: FACT, FICTION, AND OPINION

Soil Science, 1999
A critical review of 'random coil' and 'self-associating aggregate' models and of earlier concepts of the macromolecular structure of humic substances (HS) is undertaken as a result of the development of more recent information and hypotheses.
openaire   +1 more source

Synthesis of Macromolecular Substances by Condensation Polymerization and Stepwise Addition Polymerization

2001
Condensation polymerizations (polycondensations) are stepwise reactions between bifunctional or polyfunctional components, with elimination of simple molecules such as water or alcohol and the formation of macromolecular substances. For the preparation of linear condensation polymers from bifunctional compounds (the same considerations apply to ...
Dietrich Braun, Harald Cherdron, Helmut Ritter   +2 more
openaire   +1 more source

AGGREGATION PATTERNS AND MACROMOLECULAR MORPHOLOGY OF HUMIC SUBSTANCES: A FRACTAL APPROACH

Soil Science, 1999
Fractal geometry provides a powerful means for the quantitative description of heterogeneous and highly irregular systems encountered in nature. Humic substances represent a typical class of natural compounds that may be amenable to a fractal description because of their well known physical and chemical heterogeneity and molecular complexity.
openaire   +1 more source

Influence of macromolecular substances in waste cooking oil on rejuvenation properties of asphalt with different aging degrees

Construction and Building Materials, 2022
Chen Meizhu, Zhao Yuechao, Wu Shaopeng   +2 more
exaly  

Ultrasonic velocity in macromolecular substances

Journal of Polymer Science, 1949
G. Natta, M. Baccaredda
openaire   +1 more source

Macromolecular substances - their role in urolithiasis

Current Opinion in Urology, 1997
openaire   +1 more source

Determination of routine chemicals, physical indices and macromolecular substances in reconstituted tobacco using near infrared spectroscopy combined with sample set partitioning

Journal of Near Infrared Spectroscopy, 2020
Lijun Wu
exaly