Wang D.,Liaocheng University
Journal of Chemical Crystallography | Year: 2010
The imidazolyl derived complex N,N'-butylenebis(imidazole):(oxalic acid)0.5 was prepared and structurally characterized by X-ray crystallography. The title compound crystallizes in the triclinic, space group P-1, with a = 4.4373(9) Å, b = 12.882(3) Å, c = 15.319(3) Å, α = 99.91(3)°, β = 94.53(3)°, γ = 98.72(3)°, V = 847.7(3) Å3, Z = 2. Two N,N'-butylenebis(imidazole) and two oxalic acid molecules form an annulus via intermolecular hydrogen bonds, with internal dimensions of about 7.1 × 11.1 Å. Neighboring annuluses were connected by N-H•••O and C-H•••O interactions to form 1D double chain structure. Adjacent double chains stacked just above each other along the a-axis direction, this arrangement of the double chains leads the extended supramolecular architecture to show a three-dimensional porous network. Graphical Abstract: Two N,N'-butylenebis(imidazole) and two oxalic acid molecules form an annulus via intermolecular hydrogen bonds, with internal dimensions of about 7.1 × 11.1 Å. Neighboring annuluses were connected by N-H•••O and C-H•••O interactions to form 1D double chain structure. Adjacent double chains stacked just above each other along the a-axis, this arrangement of the double chains leads the extended supramolecular architecture to show a three-dimensional porous network.[Figure not available: see fulltext.] © 2010 Springer Science+Business Media, LLC.
Yang Z.,Liaocheng University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013
We study the physical mechanism and the information velocity of fast light based on the time-domain propagator governing light propagation in a dispersive system. We show that the output pulse can be regarded as the superposition of multiple "copies" of the input pulse, each traveling at a well-defined signal velocity no greater than the speed of light in vacuum, and the interference between the front edges of these copies generates the peak of the output pulse. The information velocity is defined as the ratio of the propagation distance to the mini-mum time required to complete any given information transfer process, directly reflecting how fast the signal of interest, i.e., the part of the pulse that carries the information of interest, propagates. With the peak of the output pulse representing the information, as is typical in slow- and fast-light applications, we find that the information velocity is significantly smaller than the speed of a discontinuity in the pulse, which was traditionally proposed to be the signal velocity of fast light. The analysis can also be applied to slow-light propagation. © 2013 American Physical Society.
Zhang X.,Liaocheng University
Knowledge-Based Systems | Year: 2011
The paper introduces the concepts of dual disjunctive normal forms in classical logic and fuzzy logics with involution negation. The laws of their truth values are studied. One is called duality, the other is called pseudo duality. Dual disjunctive normal forms in classical logic hold duality, and dual disjunctive normal forms in fuzzy logics with involution negation hold either duality or pseudo duality. © 2011 Elsevier B.V. All rights reserved.
Zhao Z.-J.,Liaocheng University
Physiological and Biochemical Zoology | Year: 2011
Leptin has been found to be a direct participant in the regulation of both energy intake and energy expenditure in small mammals showing seasonal declines in body mass (M b) and fat mass, but its roles in an animal exhibiting seasonally increased thermogenesis and unchanged M b remain unclear. Serum leptin levels, energy budget, and thermogenesis were measured in striped hamsters exposed to consecutive decreases in ambient temperatures ranging from 23° to -23°C. Coldexposed hamsters had significant increases in gross energy intake (GEI), the rate of basal metabolism, nonshivering thermogenesis, and activity of cytochrome c oxidase (COX) in brown adipose tissue (BAT), compared with control hamsters, indicating a cold-induced elevation of thermogenesis. Body mass and fat content were decreased in cold-exposed animals, and serum leptin levels were increased in hamsters exposed to temperatures of -8°C and below in inverse proportion to body fat content. Serum leptin levels were positively correlated with GEI and BAT COX activity in cold-exposed hamsters, but no such relationships were observed in control animals. These findings suggest that cold-exposed hamsters increase food consumption to meet the energy requirements for increased BAT thermogenesis. The increases in serum leptin levels are likely involved in increased thermogenesis in hamsters under cold stress. Cold-exposed hamsters may become leptin resistant, which is associated with impaired regulation of food intake. This new natural model of leptin resistance may also provide insight into the dynamic long-term control of energy homeostasis for animals that do not exhibit seasonal decline in M b. © 2011 by The University of Chicago.
Liu Z.,Nanjing University |
Liu Z.,Liaocheng University |
He W.,Nanjing University |
Guo Z.,Nanjing University
Chemical Society Reviews | Year: 2013
Coordination chemistry plays an essential role in the design of photoluminescent probes for metal ions. Metal coordination to organic dyes induces distinct optical responses which signal the presence of metal species of interest. Luminescent lanthanide (Ln3+) and transition metal complexes of d6, d8 and d10 configurations often exhibit unique luminescence properties different from organic dyes, such as high quantum yield, large Stokes shift, long emission wavelength and emission lifetimes, low sensitivity to microenvironments, and can be explored as lumophores to construct probes for metal ions, anions and neutral species. In this review, the design principles and coordination chemistry of metal probes based on mechanisms of PeT, PCT, ESIPT, FRET, and excimer formation will be discussed in detail. Particular attention will be given to rationales for the design of turn-on and ratiometric probes. Moreover, phosphorescent probe design based on Ln3+ and d6, d8 and d 10-metal complexes are also presented via discussing certain factors affecting the phosphorescence of these metal complexes. A survey of the latest progress in photoluminescent probes for identification of essential metal cations in the human body or toxic metal cations in the environment will be presented focusing on their design rationales and sensing behaviors. Metal complex-based photoluminescent probes for biorelated anions such as PPi, and neutral biomolecules ATP, NO, and H2S will be discussed also in the context of their metal coordination-related sensing behaviors and design approaches. © 2013 The Royal Society of Chemistry.