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91.
92.
An analog of the injective profile of a ring, with relative injectivity replaced by relative pure-injectivity, is investigated. Emphasis is placed on comparing and contrasting the properties of both profiles. In particular, the analog in this context of the notion of poor modules is considered and properties of pure-injectively poor modules are determined. While we do not know of any ring that does not have pure-injectively poor modules, their existence has not been determined in general. Rings having pure-injectively poor modules of various types are characterized. 相似文献
93.
94.
Mabkhot YN Al-Majid AM Alamary AS Warad I Sedigi Y 《Molecules (Basel, Switzerland)》2011,16(6):5142-5148
Facile and convenient syntheses of bisdimethylthieno[2,3-b]thiophen-2,5-diyl bis(oxazole-2-amine), bis(1H-imidazol-2-amine), bis((3a)-H-indole),[1,2-a]pyrimidine), bis(1H-imidazo[1,2-b][1,2,4]triazole) and bis(9H-benzo[d]imidazo[1,2-a]imidazole) derivatives incorporating a thieno[2,3-b]thiophene moiety from the versatile and readily accessible 1,1'(3,4-dimethylthieno[2,3-b]thiophene-2,5-diyl)-bis(2-bromo-ethanone) (1) are described. 相似文献
95.
Mohammad Akbar Ali Ai Ling Tan Aminul Huq Mirza Jose H. Santos Aimi Hanisah Bte Hj Abdullah 《Transition Metal Chemistry》2012,37(7):651-659
Four tridentate ONS ligands, namely 2-hydroxyacetophenonethiosemicarbazone (H2L1), the 2-hydroxyacetophenone Schiff base of S-methyldithiocarbazate (H2L2), the 2-hydroxy-5-nitrobenzaldehyde Schiff base of S-methyldithiocarbazate (H2L3), and the 2-hydroxy-5-nitrobenzaldehyde Schiff base of S-benzyldithiocarbazate (H2L4), and their complexes of general formula [Ni(HL1)2], [ML] (M?=?NiII or CuII; L?=?L1, L2, L3 and L4), [Co(HL)(L); L?=?L1, L2, L3 and L4] and [ML(B)] (M?=?NiII or CuII; L?=?L2 and L4; B?=?py, PPh3) have been prepared and characterized by physico-chemical techniques. Spectroscopic evidence indicates that the Schiff bases behave as ONS tridentate chelating agents. X-ray crystallographic structure determination of [NiL2(PPh3)] and [CuL4(py)] indicates that these complexes have an approximately square-planar structure with the Schiff bases acting as dinegatively charged ONS tridentate ligands coordinating via the phenoxide oxygen, azomethine nitrogen and thiolate sulfur atoms. The electrochemical properties of the complexes have been studied by cyclic voltammetry. 相似文献
96.
Jiayun Guo Dongge Ma Fulin Sun Guilin Zhuang Qi Wang Abdullah M.Al-Enizi Ayman Nafady Shengqian Ma 《中国科学:化学(英文版)》2022,65(9):1704-1709
The heterojunction composed of covalent organic frameworks(COFs) with adjustable structure and other photocatalysts has great potential in the field of photocatalysis. However, effectively enhancing the photocatalytic performance of organic heterojunctions by designing the structure of COFs has not been explored. Herein, TPB-TP-COFs fabricated from 1,3,5-tris(4-amino-phenyl)benzene(TPB) and terephthalaldehyde(TP) with different substituents(-H,-OH,-OCH3,-Br and-F groups),were applied ... 相似文献
97.
Sturmian comparison theory for half‐linear and nonlinear differential equations via Picone identity 下载免费PDF全文
Abdullah Özbekler 《Mathematical Methods in the Applied Sciences》2017,40(8):3100-3110
In this paper, Sturmian comparison theory is developed for the pair of second‐order differential equations; first of which is the nonlinear differential equations of the form (1) and the second is the half‐linear differential equations (2) where Φα (s ) = |s |α ? 1s and α 1 > ? > α m > β > α m + 1 > ? > α n > 0. Under the assumption that the solution of 2 has two consecutive zeros, we obtain Sturm–Picone type and Leighton type comparison theorems for 1 by employing the new nonlinear version of Picone formula that we derive. Wirtinger type inequalities and several oscillation criteria are also attained for 1 . Examples are given to illustrate the relevance of the results. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
98.
The effect of block copolymer structure on the internalization of polymeric micelles by human breast cancer cells 总被引:3,自引:0,他引:3
The objective of this study was to assess the effect of hydrophilic/hydrophobic block chain lengths on the internalization of poly(ethylene oxide)-block-poly(varepsilon-caprolactone) (PEO-b-PCL) micelles by cancer cells. PEO-b-PCL block copolymers with varied PEO and PCL chain lengths were synthesized, assembled to polymeric micelles and loaded with a hydrophobic fluorescent probe (DiI) through a co-solvent evaporation method of physical encapsulation. The slow release of the fluorescent probe from the micellar structure was evidenced following DiI transfer to lipid vesicles. The extent of micellar uptake by cancer cells was investigated through their incubation with MCF-7 cells followed by measurement of the fluorescent emission intensity of DiI (lambda=550 nm) in separated lysed cells. Cellular internalization of polymeric micelles was confirmed by laser scanning microscopy. The mechanism of micellar uptake was investigated by pretreatment of MCF-7 cells with chlorpromazine and cytochalasin B. Encapsulation of DiI in PEO-b-PCL micelles lowered the extent and rate of hydrophobic probe internalization by cancer cells. For polymeric micelles with 5000 gmol(-1) of PCL and varied PEO molecular weights of 2000, 5000 and 13,000 gmol(-1), maximum uptake was observed at a PEO molecular weight of 5000 gmol(-1). For polymeric micelles with 5000 gmol(-1) of PEO and varied PCL molecular weights of 5000, 13,000 and 24,000 gmol(-1), maximum uptake was observed at 13,000 gmol(-1) of PCL. Chlorpromazine reduced the cellular uptake of PEO-b-PCL micelles independent from the block copolymer structure, pointing to the involvement of clathrin mediated endocytosis mechanisms in the uptake of polymeric micelles by cancer cells. Inhibition of cellular uptake of PEO-b-PCL micelles by cytochalasin B, on the other hand, was found to be dependent on the chemical structure of the core/shell forming blocks. 相似文献
99.
A new type of optoelectronic cellular neural network has been developed by providing the capability of coefficients adjusment of cellular neural network (CNN) using Widrow based perceptron learning algorithm. The new supervised cellular neural network is called Widrow-CNN. Despite the unsupervised CNN, the proposed learning algorithm allows to use the Widrow-CNN for various image processing applications easily. Also, the capability of CNN for image processing and feature extraction has been improved using basic joint transform correlation architecture. This hardware application presents high speed processing capability compared to digital applications. The optoelectronic Widrow-CNN has been tested for classic CNN feature extraction problems. It yields the best results even in case of hard feature extraction problems such as diagonal line detection and vertical line determination. 相似文献
100.
Ye Jingyao Al-Jobory Alaa Zhang Qian-Chong Cao Wenqiang Alshehab Abdullah Qu Kai Alotaibi Turki Chen Hang Liu Junyang Ismael Ali K. Chen Zhong-Ning Lambert Colin J. Hong Wenjing 《中国科学:化学(英文版)》2022,65(9):1822-1828
Science China Chemistry - Destructive quantum interference (DQI) provides a unique approach to controlling the leakage current in the OFF state of molecular devices. However, the DQI in... 相似文献