Results 121 to 130 of about 4,275,365 (347)

Molecular study of lipids in humic acids by sequential chemical degradation [PDF]

open access: yes, 2009
Lipidy v půdě vykazují poměrně vysokou resistenci k biodegradaci, mohou proto tak zajistit informace o zdrojích organické hmoty a diagenetických procesech. Půdní organická hmota je vysoce heterogenní a vyskytují se v ní různé dynamické systémy.
Bachratá, Radka
core  

Tunable Coordination Number in Non‐Metal‐Introduced Copper Catalysts Enables High‐Performance Electrochemical CO2 Reduction to C2 Products

open access: yesAdvanced Functional Materials, EarlyView.
Copper catalysts introduced with different non‐metallic elements regulating the coordination number of Cu are prepared by magnetron sputtering. Reducing the Cu coordination number enhances C─C coupling and boosts C2+ product selectivity, by lowering the energy barrier for the *CO → *CHO conversion step. The optimized Si‐doped Cu catalyst achieves a C2+
Xiaoye Du   +8 more
wiley   +1 more source

Advanced acoustic cavity technology [PDF]

open access: yes
A series of rocket motor firings was performed in a modified linear aerospike thrust chamber with the H2/O2 propellant combination to allow determination of the physical properties of the combustion gases in acoustic cavities located in the chamber side ...
Hines, W. S., Kusak, L., Oberg, C. L.
core   +1 more source

Reconfigurable Microenvironments Uncover Mechano‐Sensing Timescales and Direct Cell Polarity

open access: yesAdvanced Functional Materials, EarlyView.
A synthetic DNA‐crosslinked cell culture matrix enables control over the mechanical microenvironment surrounding cells. Independent tuning of stiffness and stress relaxation uncovers distinct timescales of mechano‐sensing that regulate cell behavior.
Syuan‐Ku Hsiao   +4 more
wiley   +1 more source

Descriptors for terpene esters from chromatographic and partition measurements: Estimation of human odor detection thresholds [PDF]

open access: yes, 2020
We have used gas chromatographic retention data together with other data to obtain Abraham descriptors for 30 terpene esters. These include the air-water partition coefficient, as log Kw, for which no experimental values are available for any terpene ...
Abraham, Michael H   +2 more
core  

Mechanochemistry‐Assisted Solvent‐Free Supramolecular Engineering for Atomic‐Layered Carbon Nitride Nanosheets with Enhanced Photocatalytic Hydrogen Evolution

open access: yesAdvanced Functional Materials, EarlyView.
A solvent‐free mechanochemistry‐enabled supramolecular engineering strategy is developed to directly synthesize covalent‐interconnected two‐dimensional atomic‐layered carbon nitride nanosheets photocatalyst, bypassing conventional top‐down exfoliation requirements.
Fanglei Yao   +7 more
wiley   +1 more source

Characterisation of the Volatile Compounds and Key Odourants in Japanese Mandarins by Gas Chromatography–Mass Spectrometry and Gas Chromatography–Olfactometry

open access: yesSeparations
Japanese mandarins are becoming increasingly popular due to their pleasant aroma. The volatiles in four varieties of Japanese mandarins (Iyokan, Ponkan, Shiranui, and Unshiu mikan) were extracted by headspace solid-phase microextraction (HS-SPME) and ...
Lingyi Li   +9 more
doaj   +1 more source

Tailoring Redox Active Sites with Dual‐Interfacial Electric Fields for Concurrent Photocatalytic Biomass Valorization and H2 Production

open access: yesAdvanced Functional Materials, EarlyView.
A rationally engineered bifunctional photocatalyst is reported, which achieves simultaneous selective oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) to 2,5‐diformylfuran (DFF) and efficient H2 evolution. By precisely positioning Au and Co3O4 on Zn3In2S6 nanosheet, dual interfacial electric fields are well constructed to spatially separate ...
Shiqing Li   +8 more
wiley   +1 more source

Correlation Techniques Applied to Gas Chromatography: A Re-Appraisal

open access: yesMeasurement + Control, 1972
The case for applying correlation techniques to gas chromatography has been re-examined following the introduction of on-line cross-correlators, and it is concluded that there is still little scope for these techniques in a normal chromatograph situation.
G C Moss, K R Godfrey
doaj   +1 more source

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