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A Kinetic Study of Thermal Degradations of Chitosan/Polycaprolactam Blends
Liao, Shen-Kun,Hung, Chi-Chih,Lim, Ming-Fung The Polymer Society of Korea 2004 Macromolecular Research Vol.12 No.5
We have used FT-IR spectra to explain the effects of hydrogen bonding between chitosan and polycaprolactam (PA6). A dynamic mechanical analysis study suggested that the optimum chitosan and PA6 miscibility under the conditions of this experiment were obtained at a blending ratio of 40:60. We studied the thermal degradation of chitosan blended with PA6 (chitosan/PA6) by thermogravimetric analysis and kinetic analysis (by the Ozawa method). Dry chitosan and PA6 exhibited a single stage of thermal degradation and chitosan/PA6 blends having> 20 wt% PA6 exhibited at least two stages of degradation. In chitosan/PA6 blends, chitosan underwent the first stage of thermal degradation; the second stage proceeded at a temperature lower than that of PA6, because the decomposition product of chitosan accelerated the degradation of PA6. The activation energies of the blends were between 130 and 165 kJ/mol, which are also lower than that of PA6.
Liao, Qiaogan,Yang, Kun,Chen, Jianhua,Koh, Chang Woo,Tang, Yumin,Su, Mengyao,Wang, Yang,Yang, Yinhua,Feng, Xiyuan,He, Zhubing,Woo, Han Young,Guo, Xugang American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.34
<P>Halogenated solvents are prevailingly used in the fabrication of nonfullerene organic solar cells (NF-OSCs) at the current stage, imposing significant restraints on their practical applications. By copolymerizing phthalimide or thieno[3,4-<I>c</I>]pyrrole-4,6-dione (TPD) with 1,4-di(3-alkoxy-2-thienyl)-2,5-difluorophenylene (DOTFP), which features intramolecular noncovalent interactions, the backbone planarity of the resulting DOTFP-based polymers can be effectively tuned, yielding distinct solubilities, aggregation characters, and chain packing properties. Polymer DOTFP-PhI with a more twisted backbone showed a lower degree of aggregation in solution but an increased film crystallinity than polymer DOTFP-TPD. An organic thin-film transistor and NF-OSC based on DOTFP-PhI, processed with a nonhalogenated solvent, exhibited a high hole mobility up to 1.20 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP> and a promising power conversion efficiency up to 10.65%, respectively. The results demonstrate that DOTFP is a promising building block for constructing wide bandgap polymers and backbone coplanarity tuning is an effective strategy to develop high-performance organic semiconductors processable with a nonhalogenated solvent.</P> [FIG OMISSION]</BR>
Kun Wen,Li Han,Zhi-ting Zhou,Zhen-nan Fan,Yong Liao,Jun Wang,Zhang Sun,Bing Yao,Bide Zhang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3
To obtain more precise and rational calculation details of the loss and heat of a damper winding in a tubular hydro-generator, this study develops a three-dimensional, fi nite-element, electromagnetic-temperature fi eld close-coupling model of the damper winding. On the basis of multi-physical fi eld coupled theory, the model fully considers the temperature eff ects of the damper winding resistivities and heat conductivities, and the eddy current loss in the end region of the damper winding. The model was verifi ed by direct tests of the damper winding temperature. Unlike the conventional weak-coupling model, the proposed close-coupling model fully captures the interaction between the electromagnetic and temperature fi elds. Therefore, of the model more accurately and reasonably calculates the loss and heat of the damper winding than the conventional model. The proposed calculation model can properly assess the loss and heat of damper windings in large hydro-generators, which is helpful for improving the design standards of hydro-generators.
Flow field characteristics of an agitator system of a large diameter slurry-water shield machine
Junjie Liao,Kun Bai,Yi-Min Xia,Haizhen Li,Xianqiong Zhao,Xuemeng Xiao,Yang Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.4
A numerical model was established for calculation in this study on the basis of the standard k-epsilon turbulence model and the discrete phase model of the Euler-Lagrange equation. Results of the particle image velocimetry experiment were used to verify the reliability of the numerical model. The effects of the rotation speeds, slurry densities, and impeller structures on the flow field characteristics, including velocity distribution, ballast fluidity, and power loss, were also investigated. The results indicate that the increase of rotation speed has little influence on the flow field near the wall and bottom of the agitator, and the agitator performs well when the speed is set between 30 rpm and 40 rpm. The increase of the slurry density will increase the pressure loss between the inlet and the outlet, and it will also increase the load of the agitator. Hence, the slurry density must be less than 1400 kg/m 3 . The baffle can improve the velocity distribution of the flow field and the slag discharge capacity of the agitator.
Sha Liao,Shi-Yong Fan,Qin Liu,Chang-Kun L,Jia Chen,Jing-Lai Li,Zhi-Wei Zhang,Zhen-Qing Zhang,Bo-Hua Zhong,Jian-Wei Xie 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.11
Chronic hepatitis B virus (HBV) infection maylead to liver cirrhosis and hepatocellular carcinoma, butfew drugs are available for its treatment. Acyclic nucleosidephosphonates (ANPs) have remarkable antivirusactivities but are not easily absorbed from the gastrointestinaltract and accumulate in the kidneys, resulting innephrotoxicity. Therefore, there is a need to find effectiveliver site-specific prodrugs. The dipivaloyloxymethyl esterof 9-(2-phosphonylmethoxyethyl)adenine (PMEA)—adefovirdipivoxil (ADV)—is a first-line therapy drug forchronic hepatitis B with a low therapeutic index because ofrenal toxicity and low hepatic uptake. In this study, a seriesof PMEA derivatives were synthesized to enhance plasmastability and liver release. The metabolic stability of ADV(Chemical I) and its two analogues (Chemicals II and III)was evaluated in rat plasma and liver homogenate in vitro. An ion-pair reverse-phase HPLC–UV method and a hybridion trap and high-resolution time-of-flight mass spectrometry(LC-IT-TOF-MS) were used to evaluate the degradationrate of the analogues and to identify their intermediatemetabolites, respectively. Chemicals I and II were hydrolyzedby cleavage of the C–O bond to give monoesters. Sufficient enzymatic activation in the liver homogenatethrough a relatively simple metabolic pathway, in additionto a favorable stability profile in rat plasma, made ChemicalII an optimal candidate. Next, six analogues based onthe structure of Chemical II were synthesized and evaluatedin plasma and liver homogenate. Compared toChemical II, these compounds generated less active PMEAlevels in rat liver homogenate. Therefore, chemical modificationof Chemical II may lead to new promising PMEAderivatives with enhanced plasma stability and liveractivation.
Luo Jia,Yang Yiting,Liao Kun,Liu Bin,Chen Ying,Shen Linyuan,Chen Lei,Jiang An’an,Liu Yihui,Li Qiang,Wang Jinyong,Li Xuewei,Zhang Shunhua,Zhu Li 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.8
Objective: The QingYu pig is well known for its excellent meat quality attributes in Sichuan province, China. In order to improve its production efficiency, the determination of genetic factors contributing to quantifiable economic traits of livestock is important. Moreover, the cross-breeding of QingYu pigs with western breeds possessing strong growth attributes is an efficient way to improve the performance of this breed. Methods: Here, the genetic parameters of several important reproductive traits of QingYu pigs were estimated, include total number born (TNB), number born alive, litter birth weight, individual birth weight, number of piglets weaned, litter weaning weight, and individual weaning weight. The data was analyzed using the ASReml 3.0 software (NSW Inc., Sydney, Australia). Furthermore, the effects of crossing Berkshire with QingYu (BQ) pigs on carcass and meat quality traits, as well as the effects of slaughter weight on carcass and meat quality of BQ were characterized. Results: QingYu pigs exhibited superior reproductive traits. The TNB available to QingYu pigs was more than 8 per parity. The observed repeatability of the reproductive traits of the QingYu pigs was between 0.10 and 0.23. The significantly correlated genetic and phenotypic of reproduction traits were consistent. Interestingly, the BQ pigs exhibited improved carcass quality, with a significant increase in loin muscle area, lean percentage and reduction in sebum percentage. As a result, BQ had higher L45min, lower cooking scores, and lower drip loss. In addition, the loin muscle area, body length, and sebum percentage were significantly higher in 90 and 100 kg animals. Cooking loss showed a significant increase at 80 kg, and marbling increased significantly from 90 kg. Conclusion: The results of this study suggest that QingYu pigs exhibit excellent reproductive properties and heritability of these traits. Crossing with Berkshire is an efficient strategy to improve the carcass and meat quality of QingYu pigs for commercial operations. Furthermore, it appears as though the optimal slaughter weight of BQ pigs is at approximately 90 kg.
Chen, Jianhua,Wang, Lei,Yang, Jie,Yang, Kun,Uddin, Mohammad Afsar,Tang, Yumin,Zhou, Xin,Liao, Qiaogan,Yu, Jianwei,Liu, Bin,Woo, Han Young,Guo, Xugang American Chemical Society 2019 Macromolecules Vol.52 No.1
<P>Two carboxylate-functionalized wide band gap polymers, 2TC-TT-BDTFT and 2T-TTC-BDTFT, which feature a fluorinated benzodithiophene (BDTFT)-<I>alt</I>-2,5-di(thiophen-2-yl)thieno[3,2-<I>b</I>]thiophene (2T-TT) backbone having different carboxylate attaching positions, were designed and synthesized. By variation of the substitution position of carboxylate groups on the 2T-TT unit, the backbone conformation of the designed building blocks 2TC-TT and 2T-TTC and their corresponding donor-acceptor polymers was fine-tuned as demonstrated by single crystal study and DFT calculation, thus yielding a large device performance difference in organic solar cells. As a result of the relatively higher planarity of the 2T-TTC unit in which the two carboxylate groups were attached on the inner thieno[3,2-<I>b</I>]thiophene moiety, the 2T-TTC-BDTFT polymer exhibited a red-shifted UV-vis absorption, stronger aggregation, and improved charge transport property than its polymer analogue 2TC-TT-BDTFT, in which the two outer thiophene rings were functionalized with carboxylate groups. Benefiting from the improved exciton dissociation and charge collection efficiency, better film morphology, and higher photoresponse, non-fullerene organic solar cells based on 2T-TTC-BDTFT:m-ITIC achieved a power conversion efficiency (PCE) of 11.15% with a fill factor (FF) of ∼70%, while the 2TC-TT-BDTFT:m-ITIC cells showed a relatively lower PCE of 9.65% and FF of 59.31%. The much higher FF of 2T-TTC-BDTFT-based solar cells reflects the great merit of the carboxylation on thienothiophene moiety rather than the outer thiophene counterpart. Therefore, the modulation of the carboxylate position on polymer backbones is an efficient strategy to tune the backbone conformation, interchain packing, film morphology, and the resulting optical, electrical, and photovoltaic properties. Moreover, both the 2T-TTC-BDTFT:m-ITIC and 2TC-TT-BDTFT:m-ITIC solar cells showed excellent stability during annealing and long-term storage. These results demonstrate that carboxylate-functionalized 2T-TTC and 2TC-TT have great potentials as a weak electron-accepting building block for wide band gap polymers for high-performance non-fullerene organic solar cells, and the carboxylate position on the polymer backbones is critical for performance improvement of organic photovoltaic devices.</P> [FIG OMISSION]</BR>