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51.
The effects of four factors (different side chains, side-chain disorder, conformational change, and ions and water) on the energy band structures of proteins have been investigated with the aid of the CNDO/2 crystal orbital method. The results indicate that these factors are very important. The consequences of these effects on the semiconductive properties of proteins are discussed. 相似文献
52.
Thiocyanate (SCN) adsorption on an Au electrode is examined using surface-enhanced Raman scattering (SERS) measurements, along with detailed density functional theory (DFT) calculations. Both the calculation and the spectroscopic measurements show that three different geometries are adopted by SCN adsorption in the potential region studied (0.0 V 相似文献
53.
The geometric and electronic structures of FeS(2) (100) surface have been studied by a quantum-mechanical calculation using a total-energy pseudopotential code, CASTEP. The (100) surface is very stable and does not give any significant geometric relaxation. The electronic structure of FeS(2) (100) surface is characterized by the appearance of new native surface states in the bulk band gap, which correspond to antibonding mixed Fea-Ssp(3) states. These surface states play an important role as mediators of electron transfer on both anodic and cathodic sites in the incipient oxidation of pyrite. Moreover, the (100) surface has small band gaps and shows some metallic character. It is predicted that the rate of cathodic reductive reaction of O(2) in the incipient oxidation of pyrite is much faster than previously considered. The transport of electrons from the anodic sites to the cathodic sites on the (100) surface is faster and hole injection of anodic sites is not the rate-determining step. So we can deduce that the rate-determining step of incipient oxidation for pyrite consists of both electron transfer of pyrite/aqueous O(2) interface and the splitting of H(2)O. 相似文献
54.
Xiao Wen Hu Zhi Min Zheng Cai Hong Xu 《中国化学快报》2007,18(11):1351-1352
Three new 1,3-bis(phenylethynyl)disilazanes were synthesized from the reaction of 1,3-dichlorodisilazanes with (phenylethy- nyl)lithium,and characterized by infrared (IR) spectra,nuclear magnetic resonance (NMR) and mass spectrometry (MS). 相似文献
55.
56.
Determination of amino acids in a complex matrix without derivatization is advantageous, however, difficulties are found in both the detection and the separation of those compounds. In this study, a rapid and reliable LC-MS-MS method for the quantitation of underivatized amino acids in exocellular media was established. Injections were made directly after centrifugation of the samples, without further preparation. The separation of seven underivatized amino acids was achieved on a reversed-phase C18 column with pentadecafluorooctanoic acid as a volatile ion-pair reagent, and the specific detection of most amino acids was achieved by MS-MS of the specific transitions [M + H]+-->[M + H - 46]+. The calibration curves of all analytes were linear over the range of 1.0-1000 microg ml(-1) and the detection limits ranged from 0.1 to 5 ng ml(-1), with an injection volume of 20 microl. The inter-day and intra-day precisions ranged from 2.6 to 5.7% and 4.8 to 8.2%, respectively; the mean recoveries of the seven analytes were 81-104%, 91-107% and 93-101% respectively at the spiked level of 10, 40 and 200 microg ml(-1). A large number of fermentation samples were analysed using this method. The technique is simple, rapid, selective and sensitive, and shows potential for the high-throughput quantitation of amino acids from other biological matrices. 相似文献
57.
H. A. Al-Salah H. X. Xiao J. A. McLean Jr. K. C. Frisch 《Journal of polymer science. Part A, Polymer chemistry》1988,26(6):1609-1620
Polyurethane (PU) cationomers have been synthesized by quaternizing tertiary amine-containing linear polyurethanes using different quaternizers containing acid groups. The effect of chemical structure of PU cationomers on the physical properties was studied. The mechanical properties of PU cationomers were improved with decreasing molecular weight of poly(caprolactone) glycol, and increasing concentration of quaternary ammonium. Decreasing the carbon number in the alkyl group of the N-alkyl diethanol-amine chain-extenders, and using rigid symmetrical diisocyanates, the mechanical properties of the PU cationomers were increased. The effects of these factors on the glass transition temperature of PU cationomers were also examined. The mechanical properties of the PU cationomers decreased by immersion in water and recovered after removal of the water. 相似文献
58.
Energy storage is an important adjustment method to improve the economy and reliability of a power system. Due to the complexity of the coupling relationship of elements such as the power source, load, and energy storage in the microgrid, there are problems of insufficient performance in terms of economic operation and efficient dispatching. In view of this, this paper proposes an energy storage configuration optimization model based on reinforcement learning and battery state of health assessment. Firstly, a quantitative assessment of battery health life loss based on deep learning was performed. Secondly, on the basis of considering comprehensive energy complementarity, a two-layer optimal configuration model was designed to optimize the capacity configuration and dispatch operation. Finally, the feasibility of the proposed method in microgrid energy storage planning and operation was verified by experimentation. By integrating reinforcement learning and traditional optimization methods, the proposed method did not rely on the accurate prediction of the power supply and load and can make decisions based only on the real-time information of the microgrid. In this paper, the advantages and disadvantages of the proposed method and existing methods were analyzed, and the results show that the proposed method can effectively improve the performance of dynamic planning for energy storage in microgrids. 相似文献
59.
60.
Zelong Gong Xuefeng Gao Qingqing Yang Jingxian Lun Hansen Xiao Jiayu Zhong Hong Cao 《Molecules (Basel, Switzerland)》2022,27(13)
Enterovirus 71 (EV71) is a dominant pathogenic agent that may cause severe central nervous system (CNS) diseases among infants and young children in the Asia-pacific. The inflammasome is closely implicated in EV71-induced CNS injuries through a series of signaling pathways. However, the activation pathway of NLRP3 inflammasome involved in EV71-mediated CNS injuries remains poorly defined. In the studies, EV71 infection, ERK1/2 phosphorylation, and activation of NLRP3 are abolished in glioblastoma cells with low vimentin expression by CRISPR/Cas9-mediated knockdown. PD098059, an inhibitor of p-ERK, remarkably blocks the vimentin-mediated ERK1/2 phosphorylation in EV71-infected cells. Nuclear translocation of NF-κB p65 is dependent on p-ERK in a time-dependent manner. Moreover, NLRP3 activation and caspase-1 production are limited in EV71-infected cells upon the caffeic acid phenethyl ester (CAPE) administration, an inhibitor of NF-κB, which contributes to the inflammasome regulation. In conclusion, these results suggest that EV71-mediated NLRP3 inflammasome could be activated via the VIM-ERK-NF-κB pathway, and the treatment of the dephosphorylation of ERK and NF-κB inhibitors is beneficial to host defense in EV71-infected CNS. 相似文献