Results 71 to 80 of about 202,211 (159)

Analysis of Methyl Substitution in Phenolic Compounds as Potential Biofuel Additives: From Solid‐State Description to Antioxidant Potential

open access: yesChemistrySelect, Volume 11, Issue 2, 15 January 2026.
The rising demand for renewable energy points to biodiesel as a viable fossil fuel alternative, yet its limited oxidative stability remains a challenge. This study reveals that methyl‐substituted hydroquinone derivatives exhibit enhanced antioxidant capacity, suggesting their promise as biofuel additives.
João P. M. Rodrigues   +5 more
wiley   +1 more source

Los modelos teóricos en el diseño de una “química para todos” [PDF]

open access: yes
El presente trabajo forma parte de uno mayor (Fondecyt 1130759) en cual nos centramos en la aportación teórica que se deriva de las acciones que se llevan a cabo en la actividad experimental en química.
Izquierdo, Mercè, Merino, Cristian
core   +1 more source

Análise de episódios de ensino : articulando os discursos teórico e prático na formação de professores [PDF]

open access: yes, 2009
O presente trabalho apresenta a estrutura de uma disciplina de prática de ensino que está fundamentada na matriz sociocultural. A ação mediada é sugerida na disciplina como uma construção teórica que permite desenvolver um modelo de organização do ensino,
Giordan Santos, M., Posso, A.
core   +2 more sources

Planar and Pyramidal Pentacoordinate Selenium Atoms

open access: yesChemistry – A European Journal, Volume 31, Issue 72, December 23, 2025.
Planar (D5h) and pyramidal (C5v) dianionic clusters, SeM5X52− (M = LiK; X = FBr), showcase pentacoordinate selenium atoms stabilized by geometric confinement and electrostatic interactions with surrounding alkali and halogen atoms. Abstract A systematic computational exploration of the dianionic systems SeM5X52− (M = Li─Cs; X = F─I) was conducted to ...
Luz Diego   +3 more
wiley   +1 more source

A resolução de problemas no química no ix congreso internacional sobre investigación en didáctica de las ciencias [PDF]

open access: yes, 2017
Este estudo analisou os trabalhos sobre a resolução de problemas em Química apresentados no IX Congreso Internacional sobre Investigación en Didáctica de las Ciencias. Nos anais desse evento foram identificadas dez (10) pesquisas sobre esse tema.
dos Santos Fernandes, Lucas   +1 more
core   +1 more source

La necesidad de un cambio metodológico en la enseñanza del equilibrio químico : limitaciones del principio de Le Chatelier [PDF]

open access: yes, 1993
This paper studies the didactic approach used in teaching Le Chatelier's Principle, showing that its usual formulation is ambiguous, and reports the way Chemistry textbooks use this principle in some specific cases with no mention of its limitations. The
Castelló Hernández, Manuel   +3 more
core   +2 more sources

Unravelling Lithium Interactions in Non-Flammable Gel Polymer Electrolytes: A Density Functional Theory and Molecular Dynamics Study

open access: yesBatteries
Lithium metal batteries (LiMBs) have emerged as extremely viable options for next-generation energy storage owing to their elevated energy density and improved theoretical specific capacity relative to traditional lithium batteries.
Nasser AL-Hamdani   +4 more
doaj   +1 more source

Diels‐Alder Reactivity of a Chiral Anthracene Template with Symmetrical and Unsymmetrical Dienophiles: A DFT Study

open access: yesChemistryOpen, 2020
In this work, we used Density Functional Theory calculations to assess the factors that control the reactivity of a chiral anthracene template with three sets of dienophiles including maleic anhydrides, maleimides and acetoxy lactones in the context of ...
Jennifer P. Hernández‐Mancera   +2 more
doaj   +1 more source

Use of multimedia technology for stereochemistry teaching at university level [PDF]

open access: yes, 2012
En la enseñanza de la química, el mayor inconveniente es que los átomos y las moléculas son estructuras muy pequeñas a las cuáles no tenemos posibilidad de observar.
Muscia, Gisela Celeste   +1 more
core  

¿Cuánto tiempo se estudia química antes de entrar a la universidad?

open access: yesEducación Química, 2018
Durante una discusión en la XI Conferencia Internacional sobre Educación Química, celebrada recientemente (25-30 de agosto de 1991) en York, Inglaterra, algunos de los participantes nos preguntamos acerca de la cantidad de horas de química que un ...
José Antonio Chamizo
doaj   +1 more source

Home - About - Disclaimer - Privacy