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排序方式: 共有229条查询结果,搜索用时 234 毫秒
221.
In an effort to reduce thermal shrinkage and improve electrochemical performance of porous polypropylene (PP) separators for lithium-ion batteries, a new composite separator is developed by introducing ceramic coated layers on both sides of PP separator through a dip-coating process. The coated layers are comprised of heat-resistant and hydrophilic silica nanoparticles and polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) binders. Highly porous honeycomb structure is formed and the thickness of the layer is only about 700 nm. In comparison to the pristine PP separator, the composite separator shows significant reduction in thermal shrinkage and improvement in liquid electrolyte uptake and ionic conduction, which play an important role in improving cell performance such as discharge capacity, C-rate capability, cycle performance and coulombic efficiency. 相似文献
222.
Li Y Chong H Meng X Wang S Zhu M Guo Q 《Dalton transactions (Cambridge, England : 2003)》2012,41(20):6189-6194
A new two-photon fluorescent Cd(2+) probe APQ is developed by introducing a N(1),N(1)-dimethyl-N(2)-(pyridin-2-ylmethyl)ethane-1,2-diamine binding group and a 4-methoxyphenylvinyl conjugation-enhancing group to the 2- and 6-positions of quinoline. This probe shows a large red shift and good emission enhancement under Cd(2+) binding. It also exhibits a high ion selectivity for Cd(2+) (especially over Zn(2+)) and a large two-photon absorption cross section at 710 nm. Two-photon microscopy imaging studies reveal that the new probe is non-toxic and cell-permeable and can be used to detect intracellular Cd(2+) under two-photon excitation. 相似文献
223.
Ketang Liu Ronghua Jin Tanyu Cheng Xiangming Xu Fei Gao Prof. Guohua Liu Prof. Hexing Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(48):15546-15553
A functionalized periodic mesoporous organosilica with incorporated chiral bis(cyclohexyldiamine)‐based NiII complexes within the silica framework was developed by the co‐condensation of (1R,2R)‐cyclohexyldiamine‐derived silane and ethylene‐bridge silane, followed by the complexation of NiBr2 in the presence of (1R,2R)‐N,N′‐dibenzylcyclohexyldiamine. Structural characterization by XRD, nitrogen sorption, and TEM disclosed its orderly mesostructure, and FTIR and solid‐state NMR spectroscopy demonstrated the incorporation of well‐defined single‐site bis(cyclohexyldiamine)‐based NiII active centers within periodic mesoporous organosilica. As a chiral heterogeneous catalyst, this functionalized periodic mesoporous organosilica showed high catalytic activity and excellent enantioselectivity in the asymmetric Michael addition of 1,3‐dicarbonyl compounds to nitroalkenes, comparable to those with homogeneous catalysts. In particular, this heterogeneous catalyst could be recovered easily and reused repeatedly up to nine times without obviously affecting its enantioselectivity, thus showing good potential for industrial applications. 相似文献
224.
New ratiometric two-photon fluorescent probes are developed from 6-substituted quinolines for biological Zn(2+) detection. They show large red shifts and good ratiometric responses upon Zn(2+) binding. They also exhibit high ion selectivities and large two-photon absorption cross sections at nearly 720 nm. Because the new probes are cell-permeable, they can be used to detect intracellular zinc flux under two-photon excitation. 相似文献
225.
数学建模时大学生综合应用素质培养的一种有效途径。本文首先分析数学建模在大学生实践创新能力和综合应用素质培养中的作用,在此基础上从数学建模的数学理念更新、数学模式和教学内容设计,教学方法运用等多个方面,研究了以培养学生综合应用素质为牵引的多焊接、全方位的数学建模教学模式,提出了一些创新性的实践做法,为教学建模数学与组织竞赛活动的开展提供参考。 相似文献
226.
Daoqing Fan Jiale Ou Ling Chen Lichao Zhang Zhiren Zheng Haizhu Yu Xiangming Meng Manzhou Zhu 《Molecules (Basel, Switzerland)》2023,28(1)
Recent decades have witnessed the rapid progress of nanozymes and their high promising applications in catalysis and bioclinics. However, the comprehensive synthetic procedures and harsh synthetic conditions represent significant challenges for nanozymes. In this study, monodisperse, ultrasmall gold clusters with peroxidase-like activity were prepared via a simple and robust one-pot method. The reaction of clusters with H2O2 and 3,3′,5,5′-tetramethylbenzidine (TMB) followed the Michaelis-Menton kinetics. In addition, in vitro experiments showed that the prepared clusters had good biocompatibility and cell imaging ability, indicating their future potential as multi-functional materials. 相似文献
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A series of Au films with different nominal deposition thickness d were fabricated on ionic liquid surfaces by thermal evaporation at room temperature,taken as surface-enhanced Raman scattering(SERS) substrates.Au atoms deposited on the liquid surfaces can diffuse and aggregate randomly and eventually form films with ramified structure,which consist of nanoparticles(NPs).There are amounts of ultrasmall(~1 nm or smaller) nanogaps among the Au NPs,which can dramatically enhance Raman signal.Raman spectra of R6G were investigated with the assistance of the Au films.The results indicate that the Au films with higher thickness possess better SERS performance when 5.0 ≤d ≤30.0 nm.A random distribution model of Au NPs was used in the finite-difference time-domain method and the simulation results are in good agreement with the experimental findings. 相似文献