Chemical Structure and Properties: A Modified Atoms-First, One-Semester Introductory Chemistry Course

2014 ◽  
Vol 92 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Chris P. Schaller ◽  
Kate J. Graham ◽  
Brian J. Johnson ◽  
Henry V. Jakubowski ◽  
Anna G. McKenna ◽  
...  
2014 ◽  
Vol 1048 ◽  
pp. 452-455
Author(s):  
Qiang Wang ◽  
Shi Dong Wang ◽  
Ming Chen Qi ◽  
Shu Liang Zang

Two new imidazole ionic liquid salts, 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-allyl-3-methy-imidazolium hydrogen sulfate ([EMIM]HSO4), were synthesized with direct synthesis and two-step synthesis method, using a viscosity meter, PH meter, conductivity meter, densitometer, infrared spectrometer determined its chemical structure and properties. The results show that two ionic liquids in the range is slightly different, the trend is roughly same. As the temperature increases, the viscosity decreases, PH gradually increased, the density decreases slightly, can be regarded as constant, the conductivity gradually increased. Ionic liquids of the two IR spectra analysis show its structure and synthetic route consistent with the structure of matter.


Author(s):  
Senay Ozgen ◽  
Ozgur Kivilcim Kilinc ◽  
Zeliha Selamoğlu

Flavones and flavonoids are known to have potent antioxidant activity due to intracellular free radical scavenging capacities. Flavonoids are found ubiquitously in plants as a member of polyphenolic compounds which share diverse chemical structure and properties. Quercetin is among the most efficient antioxidants of the flavonoids. The antioxidant property of quercetin has been highlighted in this review. These compounds have pivotal role in treatment of diabetes, cancers and some cardiovascular diseases.


1968 ◽  
Vol 47 (12) ◽  
pp. 864-871 ◽  
Author(s):  
Hidehiko Sugimura ◽  
Yoshihiro Osawa ◽  
Akira Ikutaand ◽  
Hidemasa Honda

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Boris Jaffrennou ◽  
Nicolas Droger ◽  
Françoise Méchin ◽  
Jean-Louis Halary ◽  
Jean-Pierre Pascault

AbstractA new polythiourethane thermosetting system based on a diisocyanate and a trithiol was studied. After characterization of the reactive species, two critical temperatures, namely Tg∞ (maximum glass transition temperature of the thermosetting system) and gelTg (Tg of the material at the gel point), were determined. The conversion at gel point was also determined and compared to the theoretical prediction. Two different characteristics of the evolution of a reactive system, Tg and conversion x as a function of time, were related. This is of particular interest for understanding the curing process, especially when non-isothermal cure schedules are used. Viscoelastic and plastic properties were investigated, with the aim of establishing connections between the chemical structure and properties through detailed analysis of the polymer chain motions (β and α relaxations). Measurements of the storage modulus at the rubbery plateau and of the critical strain intensity factor KIc complete the study.


2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Jianchao Li ◽  
Wanmin Yang ◽  
Junhong Su ◽  
Chen Yang

LaTiO3 films were prepared under various deposition temperatures using electron beam evaporation on Si and fused quartz substrates. The relationship between the deposition temperature and structure and properties of optics was investigated by XPS, XRD, and various optical testing. The results showed that the LaTiO3 film is amorphous when the deposition temperature is below 200°C. The refractive index of LaTiO3 films increases from 1.8302 to 1.9112 at 1064 nm with the rise of deposition temperature. The extinction coefficient of LaTiO3 films is less than 10−6 in the range of 350 to 1700 nm. The laser damage threshold increases at first and then decreases with the increase of deposition temperature. The maximum of the laser damage threshold was 18.18 J/cm2 when the deposition temperature was 150°C. Compared with TiO2 film, the chemical structure and the laser damage threshold of LaTiO3 film are more stable by preparation of electron beam evaporation.


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