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191.
《Electrochemistry communications》2007,9(4):708-712
An electrochemical cell designed to perform high temperature lithium battery tests has been developed adapting a typical Swagelok® cell. The high temperature cell is intended to work in a wide temperature range, namely from room temperature up to 300 °C. It has been successfully tested at 250 °C using LiFePO4 as cathode, LiTFSI as molten salt electrolyte and metallic lithium as anode. 相似文献
192.
YU Ming XU Qiang School of Materials Science Engineering East China University of Science Technology Shanghai China 《Chinese Journal of Reactive Polymers》2006,(1)
1. INTRODUCTIONThese years, HCFC-141b may be the most used blowing agent for its useful properties. But, because of its high global warming effect leading to the destruction of the ozone layer, production of HCFC141b has been forbidden. However, there are… 相似文献
193.
The stabilization modification of the halogen end groups of polystyrene prepared by atom transfer radical polymerization (ATRP) has been attempted. The reaction mechanism adopted is radical chain transfer reaction, and iso-propylbenzene is employed as not only the chain transfer agent but also the solvent. Moreover, Cu0 is used as the acceptor of the transformed halogen atom in some experiments. As evidenced by 1H NMR analysis of the modified products, the halogen end group can really be converted into the much more stable carbon-hydrogen structure. When Cu0 is not used, the conversion of the halogen end groups rises rapidly during the early stage and the increase rate slows down after about 8 h reaction. In view of the influence of reaction temperature on the modification, the conversion increases almost exponentially with temperature in the range of 80-100 °C, and the increase rate slows down at higher temperature. 1H NMR and SEC analyses prove that the modification reaction does not destroy the polymer backbone and the molecular weights remain almost the same as those of the unmodified samples. When Cu0 is introduced, the modification reaction proceeds much rapidly, the conversion of the halogen end groups rises almost linearly at the early stage and the nearly complete (>95%) dehalogenation of the polymeric chains is observed after only 12 h reaction. However, the molecular weights rise and the polydispersities become wider after the modification, which implies that the modification is accompanied with the couple termination of the polystyrene radicals besides chain transfer reaction. Furthermore, the couple termination can be restrained at some lower catalyst concentration. Indeed, the modified polymers show improved thermal stability, the initial weight loss temperatures is increased from 196 °C to 378 °C for the linear polystyrene and from 203 °C to 261 °C for the hyperbranched polystyrene. 相似文献
194.
《Spectrochimica Acta Part B: Atomic Spectroscopy》2006,61(8):959-964
As continuation of the work on fluorine, the second part of the studies of halogens in the air–acetylene flame attends to the determination of chlorine using high-resolution continuum source absorption spectrometry and molecular absorption. In case of chlorine, the diatomic InCl molecule proved to be a suitable species. For an excess of In in the flame, chlorine is converted to InCl which produces a distinctive band head at 267.24 nm that could be evaluated analytically. The influence of concentrated inorganic acids and metallic matrices on the absorption at this band head was tested. In all cases the signal proved to be unaffected, i.e., no spectral interferences were observed. However, serious chemical interferences were found in the presence of sulfuric and phosphoric acids, which could be partially eliminated by adding Ca in the form of nitrate. Moreover, nitric and hydrofluoric acids as well as Cu and Ga matrices also produced significant chemical interferences. Therefore, the method of standard additions should be used for calibration purposes. Concerning the limit of detection, a value of 3 mg L− 1 was achieved for a measurement time of 5 s in the presence of 10,000 mg L− 1 In. The calibration curve was linear up to a chlorine concentration of 1800 mg L− 1. Three certified reference materials (BCR 151, HISS-1, and PACS-2) were analyzed to test the performance of the new method, yielding good precision and accuracy. 相似文献
195.
In the present era, a major drawback of current anti-cancer drugs is the lack of satisfactory specificity towards tumor cells. Despite the presence of several therapies against cancer, tumor homing peptides are gaining importance as therapeutic agents. In this regard, the huge number of therapeutic peptides generated in recent years, demands the need to develop an effective and interpretable computational model for rapidly, effectively and automatically predicting tumor homing peptides. Therefore, a sequence-based approach referred herein as THPep has been developed to predict and analyze tumor homing peptides by using an interpretable random forest classifier in concomitant with amino acid composition, dipeptide composition and pseudo amino acid composition. An overall accuracy and Matthews correlation coefficient of 90.13% and 0.76, respectively, were achieved from the independent test set on an objective benchmark dataset. Upon comparison, it was found that THPep was superior to the existing method and holds high potential as a useful tool for predicting tumor homing peptides. For the convenience of experimental scientists, a web server for this proposed method is provided publicly at http://codes.bio/thpep/. 相似文献
196.
[structure: see text]. A fast, inexpensive, and highly efficient synthesis of aromatic polyamide dendrimers without the need for protection and deprotection steps has been developed. Dendrons and third-generation polyamide dendrimers were easily prepared by a convergent approach involving activation of a focal point with thionyl chloride, followed by condensation with unprotected AB2 building blocks. 相似文献
197.
D. Fennell Evans Martin Allen B. W. Ninham Abdel Fouda 《Journal of solution chemistry》1984,13(2):87-101
Critical micelle concentrations were determined by conductance measurements for decyl-, dodecyl-, tetradecyl- and hexadecyltrimethylammonium bromide in water at 25, 60, 95, 130, and 160°C. The results are discussed in terms of the equilibrium model and the nonlinear Poisson-Boltzmann model for micelle formation. The free energies of transferring a methylene group from water to the oil-like interior of the micelle are found to be –781 at 25°C, –796 at 60°C, –819 at 95°C, –815 at 130°C, and –787 at 160°C cal-mol–1. 相似文献
198.
《Electrochemistry communications》2007,9(4):713-717
The Si–AB5 (MmNi3.6Co0.7Al0.3Mn0.4 alloy) composites with a high tap density as anode materials for lithium-ion batteries were synthesized by ball-milling. Si nanoparticles are distributed homogeneously on the surface of the AB5 matrix. The electrochemical performance of the Si–AB5 composites as a function of Si content was investigated. It is demonstrated that the Si–AB5 composite delivers a larger reversible capacity and better cycle ability because the inactive AB5 alloy can accommodate the large volume changes of Si nanoparticles distributed on the surface of the Si–AB5 composite during cycling. In particular, the Si–AB5 composite containing 20 wt% Si with the high tap density of 2.8 g/cm3 obtained after ball-milling for 11 h exhibits an initial and maximum reversible (charge) capacity of 370 and 385 mAh/g. The high capacity retention can be achieved after 50 cycles in the potential range from 0.02 to 1.5 V. 相似文献
199.
200.