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131.
Hua J Xiao ZL Imre A Yu SH Patel U Ocola LE Divan R Koshelev A Pearson J Welp U Kwok WK 《Physical review letters》2008,101(7):077003
We investigated confinement effects on the resistive anisotropy of a superconducting niobium strip with a rectangular cross section. When its transverse dimensions are comparable to the superconducting coherence length, the angle dependent magnetoresistances at a fixed temperature can be scaled as R(theta,H) = R(H/Hctheta) where Hctheta =Hc0(cos2theta + gamma(-2)sin2theta)(-1/2) is the angular dependent critical field, gamma is the width to thickness ratio, and Hc0 is the critical field in the thickness direction at theta=0 degrees . The results can be understood in terms of the anisotropic diamagnetic energy for a given field in a one-dimensional superconductor. 相似文献
132.
In Situ Monitoring of RAFT Polymerization by Tetraphenylethylene‐Containing Agents with Aggregation‐Induced Emission Characteristics 下载免费PDF全文
Dr. Shunjie Liu Dr. Yanhua Cheng Haoke Zhang Zijie Qiu Dr. Ryan T. K. Kwok Dr. Jacky W. Y. Lam Prof. Ben Zhong Tang 《Angewandte Chemie (International ed. in English)》2018,57(21):6274-6278
A facile and efficient approach is demonstrated to visualize the polymerization in situ. A group of tetraphenylethylene (TPE)‐containing dithiocarbamates were synthesized and screened as agents for reversible addition fragmentation chain transfer (RAFT) polymerizations. The spatial‐temporal control characteristics of photochemistry enabled the RAFT polymerizations to be ON and OFF on demand under alternating visible light irradiation. The emission of TPE is sensitive to the local viscosity change owing to its aggregation‐induced emission characteristic. Quantitative information could be easily acquired by the naked eye without destroying the reaction system. Furthermore, the versatility of such a technique was well demonstrated by 12 different polymerization systems. The present approach thus demonstrated a powerful platform for understanding the controlled living radical polymerization process. 相似文献
133.
Justin R. Peters Yiu Tung Poon 《Transactions of the American Mathematical Society》1997,349(12):4825-4855
Lexicographic TAF algebras constitute a class of triangular AF
algebras which are determined by a countable ordered set , a dimension function, and a third parameter. While some of the important examples of TAF algebras belong to the class, most algebras in this class have not been studied. The semigroupoid of the algebra, the lattice of invariant projections, the Jacobson radical, and for some cases the automorphism group are computed. Necessary and sufficient conditions for analyticity are given. The results often involve the order properties of the set .
algebras which are determined by a countable ordered set , a dimension function, and a third parameter. While some of the important examples of TAF algebras belong to the class, most algebras in this class have not been studied. The semigroupoid of the algebra, the lattice of invariant projections, the Jacobson radical, and for some cases the automorphism group are computed. Necessary and sufficient conditions for analyticity are given. The results often involve the order properties of the set .
134.
H. L. Chan T. W. Lam W. K. Sung P. W. H. Wong S. M. Yiu 《Mathematics in Computer Science》2008,1(4):543-555
This paper studies several combinatorial problems arising from finding the conserved genes of two genomes (i.e., the entire
DNA of two species). The input is a collection of n maximal common substrings of the two genomes. The problem is to find, based on different criteria, a subset of such common
substrings with maximum total length. The most basic criterion requires that the common substrings selected have the same
ordering in the two genomes and they do not overlap among themselves in either genome. To capture mutations (transpositions
and reversals) between the genomes, we do not insist the substrings selected to have the same ordering. Conceptually, we allow
one ordering to go through some mutations to become the other ordering. If arbitrary mutations are allowed, the problem of
finding a maximum-length, non-overlapping subset of substrings is found to be NP-hard. However, arbitrary mutations probably
overmodel the problem and are likely to find more noise than conserved genes. We consider two criteria that attempt to model
sparse and non-overlapping mutations. We show that both can be solved in polynomial time using dynamic programming.
相似文献
135.
Tam TK Zhou J Pita M Ornatska M Minko S Katz E 《Journal of the American Chemical Society》2008,130(33):10888-10889
A switchable bioelectrocatalytic system for glucose oxidation controlled by external biochemical signals exemplifies interfacing between bioelectronic and biochemical ensembles. 相似文献
136.
The aim of this work was to investigate the perception of soundscape reproduced by an ambisonic reproduction system on a horizontal plane, how the experience of space affected the perception of soundscape reproduction, and how the sound level adjustment on soundscape reproduction affected the perception of soundscape compared with actual conditions. There were three experiments conducted: a soundwalk in situ in Manchester (United Kingdom) city centre, listening tests in Salford (United Kingdom), and listening tests in Bandung (Indonesia). The listening tests used material recorded from four locations on the soundwalk route in Manchester. The Salford listening tests were performed at the in-situ measured sound level, and the participants were asked to adjust the sound level to the level that represents actual locations. The listening test in Bandung was conducted to understand the effect of participants who never come to the actual location to the perception of soundscape and the sound level adjustment. The listening tests in Bandung were conducted at the in situ sound level, at 9.5 dB below the in situ sound level (based on the preference sound level from the experiment in Salford), and the participants were also requested to adjust the sound level to the level that represents the actual space (to examine the consistency with the experiment in Salford). In each case, soundscape perception was measured on 19 semantic differential scales. Analysis of the semantic differential results showed that the ambisonic reproduction produced a similar subjective experience to the in situ soundwalk when the reproduction sound level was 9.5 dB lower than the actual sound level in situ. Reproduction at the actual sound level in situ produced a different dimensional space. The study shows that the sound level adjustment of soundscape reproduction in laboratory experiment produces more ecologically valid results compared to the reproduction at the actual sound level in situ. 相似文献
137.
138.
Chong KF Loh KP Vedula SR Lim CT Sternschulte H Steinmüller D Sheu FS Zhong YL 《Langmuir : the ACS journal of surfaces and colloids》2007,23(10):5615-5621
The biocompatibility of diamond was investigated with a view toward correlating surface chemistry and topography with cellular adhesion and growth. The adhesion properties of normal human dermal fibroblast (NHDF) cells on microcrystalline and ultrananocrystalline diamond (UNCD) surfaces were measured using atomic force microscopy. Cell adhesion forces increased by several times on the hydrogenated diamond surfaces after UV irradiation of the surfaces in air or after functionalization with undecylenic acid. A direct correlation between initial cell adhesion forces and the subsequent cell growth was observed. Cell adhesion forces were observed to be strongest on UV-treated UNCD, and cell growth experiments showed that UNCD was intrinsically more biocompatible than microcrystalline diamond surfaces. The surface carboxylic acid groups on the functionalized diamond surface provide tethering sites for laminin to support the growth of neuron cells. Finally, using capillary injection, a surface gradient of polyethylene glycol could be assembled on top of the diamond surface for the construction of a cell gradient. 相似文献
139.
Mingpeng Chen Di Liu Baoye Zi Yuyun Chen Dong Liu Xinyu Du Feifei Li Pengfei Zhou Ye Ke Jielei Li Kin Ho Lo Chi Tat Kwok Weng Fai Ip Shi Chen Shuangpeng Wang Qingju Liu Hui Pan 《Journal of Energy Chemistry》2022,(2):405-414
Design and synthesis of noble-metal-free bifunctional catalysts for efficient and robust electrochemical water splitting are of significant importance in developing clean and renewable energy sources for sustainable energy consumption.Herein,a simple three-step strategy is reported to construct cobalt-iron nitride/alloy nanosheets on nickel foam(CoFe-NA/NF)as a bifunctional catalyst for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The electrocatalyst with optimized composition(CoFe-NA2/NF)can achieve ultralow overpotentials of 73 mV and 250 mV for HER and OER,respectively,at a current density of 10 mA cm-2 in 1 M KOH.Notably,the electrolyzer based on this electrocatalyst is able to boost the overall water splitting with a cell voltage of 1.564 V to deliver 10 mA cm-2 for at least 50 h without obvious performance decay.Furthermore,our experiment and theoretical calculation demonstrate that the combination of cobalt-iron nitride and alloy can have low hydrogen adsorption energy and facilitate water dissociation during HER.In addition,the surface reconstruction introduces metal oxyhydroxides to optimize the OER process.Our work may pave a new pathway to design bifunctional catalysts for overall water splitting. 相似文献
140.