搜索结果: 1-15 共查到“理学 silica”相关记录78条 . 查询时间(0.04 秒)
Vapour-phase crystallisation of silica from SiF4-bearing volcanic gases
SiF4 vapour crystallisation silica degassing
2015/9/10
Thermodynamic modelling of magmatic gases shows that SiF4 may be an important F-bearing species at the high
pressures typical of magma reservoirs. Upon decompression during degassing, SiF4 will react...
Hydrological Processes in the Subsurface Investigated by Water Isotopes and Silica
rainfall to runoff response isotopes
2015/3/1
The hillslope rainfall-outflow interactions, groundwater fluxes, and hydrological balance were examined in the small mountainous headwater catchment Uhlířská, the jizera Mountains, the Czech Repu...
MESMO 2: a mechanistic marine silica cycle and coupling to a simple terrestrial scheme
MESMO 2 mechanistic marine silica cycle coupling simple terrestrial scheme
2014/12/16
Here we describe the second version of Minnesota Earth System Model for Ocean biogeochemistry (MESMO 2), an earth system model of intermediate complexity, which consists of a dynamical ocean, dynamic-...
Salt marsh tidal exchange increases residence time of silica in estuaries
Salt marsh tidal exchange increases residence time of silica in estuaries
2014/7/10
We present flux measurements of dissolved silicon (DSi), biogenic Si (BSi), and dissolved inorganic nitrogen (DIN) and phosphorus (DIP) on a temperate salt marsh in Narragansett Bay, Rhode Island, ove...
Nitrogen enrichment increases net silica accumulation in a temperate salt marsh
Nitrogen enrichment increases net silica accumulation a temperate salt marsh
2014/4/2
Two New England salt marshes exposed to different N availability were assessed seasonally for 1 yr, creating the first complete salt marsh Si budgets. Triplicate seasonal measurements were collected f...
MINERALOGY AND ORIGIN OF CLAY MINERALS, SILICA AND AUTHIGENIC SILICATES IN LEG 14 SEDIMENTS
CLAY MINERALS AUTHIGENIC SILICATES MINERALOGY
2011/11/11
Preliminary X-ray, SEM, TEM, and optical mineralogical results are reported to discuss the paragenesis, age distribution,and origin of clay minerals, silica modifications and authigenic silicates foun...
Synthesis and Characterization of Silylated Kaolinite/Silica Core–Shell Nanoparticles
Core-Shell Kaolinite Modification Silane Silica
2011/11/14
Studies were conducted on the production of silane modified kaolinite/silica core-shell nanoparticles (SMKS). The SMKS nanoparticles were prepared via the sol–gel technique using tetraethyl oxysilane ...
Interstitial BiO molecule as a center of broadband IR luminescence in bismuth-doped silica glass
Interstitial BiO molecule broadband IR luminescence bismuth-doped silica glass
2011/8/18
Abstract: IR luminescence and absorption in bismuth-doped silica glass-core fibers observed recently (see [arXiv:1106.2969v1 [physics.optics]) are argued to be caused by transitions in interstitial Bi...
Microcalorimetric investigation of water vapor adsorption on silica gel
Microcalorimetry Diffusivity Silica gel–water pair Heat of adsorption
2011/11/10
Water vapor adsorption on silica gel was investigated using Tian–Calvet-type microcalorimetry. Differential heat of adsorption data was obtained. The setup of microcalorimetry was used volumetric syst...
Preparation and properties of mesoporous silica/bismaleimide/diallylbisphenol composites with improved thermal stability, mechanical and dielectric properties
thermosetting resins bismaleimide meosoporous silica dielectric properties structure-property
2011/12/14
New composites with improved thermal stability, mechanical and dielectric properties were developed, which consist of 2,2!-diallylbisphenol A (DBA)/4,4!-bismaleimidodiphenylmethane (BDM) resin and a n...
Friedel-Crafts acylation of arenes with carboxylic acids using silica gel supported AlCl3
Acylation aluminium trichloride ketones silica gel
2010/10/19
Aromatic compounds react smoothly with carboxylic acids in the presence of silica gel supported aluminium trichloride to afford the corresponding ketones with high regioselectivity in high to excellen...
Sulfonic acid-functionalized silica: a remarkably efficient heterogeneous reusable catalyst for the one-pot synthesis of 1,4-dihydropyridines
1,4-Dihydropyridine b-dicarbonyl compounds solid acid SiO2-R-SO3H
2010/10/19
An efficient one-pot method for the synthesis of 1,4-dihydropyridines from b-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under s...
Silica supported polyphosphoric acid (PPA-SiO2): an efficient and reusable heterogeneous catalyst for the one-pot synthesis of a -amino phosphonates
a -Amino phosphonates PPA-SiO2 heterogeneous catalyst
2010/10/19
An efficient green protocol is described for the preparation of a -amino phosphonates, employing a one-pot three-component condensation reaction between aldehydes, amines, and trialkyl phosphites in t...
Direct reductive amination of carbonyl compounds using sodium borohydride-silica chloride
Reductive amination silica chloride sodium borohydride
2010/10/15
A simple and convenient procedure for reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride as an active, inexpensive, recoverable, and recyclable ca...
Production, dissolution, accumulation, and potential export of biogenic silica in a Sargasso Sea mode-water eddy
Production dissolution accumulation
2014/4/16
Rates of biogenic silica (bSiO2) production, dissolution, accumulation, and potential bSiO2 export were
determined in a Sargasso Sea mode-water eddy (MWE) during two occupations in April 2007. Standi...