Dembowski-Ostrom型完全非线性函数构造的线性码权分布

Dembowski-Ostrom型完全非线性函数是目前最主要的完全非线性函数类,已发现的完全非线性函数中只有一种不属于Dembowski-Ostrom型.为此,该文首先给出Dembowski-Ostrom型完全非线性函数的定义,将已有的线性码构造推广到这一类型函数上.进而给出此类函数构造的线性码的码字与有限域上非退化二次型之间的关系,并得到相应二次型的原像分布的一些性质.通过有限域上的二次型以及指数和理论,用统一的方法完全确定了基于所有Dembowski-Ostrom型完全非线性函数构造的两类线性码的权分布.

Distribution characteristics of (CS)-C-137 in wind-eroded soil profile and its use in estimating wind erosion modulus

Due to its inert reaction in soil system and distinctive vertical distribution in soil profile, caesium-137 (Cs-137) has been used as a tracer to assess wind erosion. In this study, 62 soil samples were collected from 4 sampling sites in Taipusi County, Inner Mongolia; Caesium-137 activities for those soil samples were measured using a gamma-ray spectrometry in Sichuan University, Chengdu. Distribution pattern of Cs-137 in vertical soil profile was different for different land use and land cover types. Caesium-137 was distributed homogeneously in plow layer of cropland, and negatively exponential in low to medium cover grassland. Distribution pattern in high covered grassland was represented by a peak at 2-4 cm soil depth followed by a negative exponential curve. Based on those findings, simplified mass balance model was chosen to estimate the rate of wind erosion for cropland, while profile distribution model was used for grassland. Estimated wind erosion rates were 7990, 4270 and 1808 Mg(.)km(-2.)a(-1) for cropland, low cover grassland and medium cover grassland, respectively. Wind erosion intensity correlated negatively with plant cover.

Effects of temperature, glucose and inorganic nitrogen inputs on carbon mineralization in a Tibetan alpine meadow soil

High levels of available nitrogen (N) and carbon (C) have the potential to increase soil N and C mineralization We hypothesized that with an external labile C or N supply alpine meadow soil will have a significantly higher C mineralization potential and that temperature sensitivity of C mineralization will increase To test the hypotheses an incubation experiment was conducted with two doses of N or C supply at temperature of 5 15 and 25 C Results showed external N supply had no significant effect on CO2 emission However external C supply increased CO2 emission Temperature coefficient (Q(10)) ranged from 113 to 1 29 Significantly higher values were measured with C than with N addition and control treatment Temperature dependence of C mineralization was well-represented by exponential functions Under the control CO2 efflux rate was 425 g CO2-Cm-2 year(-1) comparable to the in situ measurement of 422 g CO2-Cm-2 year(-1) We demonstrated if N is disregarded microbial decomposition is primarily limited by lack of labile C It is predicted that labile C supply would further increase CO2 efflux from the alpine meadow soil (C) 2010 Elsevier Masson SAS All rights reserved

Lattice Boltzmann study of hydrodynamic effects in lamellar ordering process of two-dimensional quenched block copolymers

By incorporating self-consistent field theory with lattice Boltzmann method, a model for polymer melts is proposed. Compared with models based on Ginzburg-Landau free energy, our model does not employ phenomenological free energies to describe systems and can consider the chain topological details of polymers. We use this model to study the effects of hydrodynamic interactions on the dynamics of microphase separation for block copolymers. In the early stage of phase separation, an exponential growth predicted by Cahn-Hilliard treatment is found. Simulation results also show that the effect of hydrodynamic interactions can be neglected in the early stage.

Electrical instability in vanadyl-phthalocyanine thin-film transistors

We investigated the electrical instability of vanadyl-phthalocyanine (VOPc) thin-film transistors (TFTs) at various temperatures. The results demonstrate a slow threshold voltage shift in the bias stress process and a rapid recovery after the removal of bias stress, which indicates that a slower degradation process occurs in the on state while a faster removal in the off state of VOPc TFTs. The shift of threshold voltage comes from traps generated at the organic/dielectrics interface. Additionally, a relaxation time of 10(7) s was obtained at room temperature according to the stretched exponential model, which is comparable to a-Si: H TFTs. Therefore, VOPc TFTs are suitable to be applied in flat panel displays.

Exploring the Origin of Power Law Distribution in Single-Molecule Conformation Dynamics: Energy Landscape Perspectives

We explored the origin of power law distribution observed in single-molecule conformational dynamics experiments. By establishing a kinetic master equation approach to study statistically the microscopic state dynamics, we show that the underlying landscape with exponentially distributed density of states leads to power law distribution of kinetics. The exponential density of states emerges when the system becomes glassy and landscape becomes rough with significant trapping.

Relationship between charge transfer energies of Yb3+ and Sm3+ and crystal environmental factor

Relationship between charge transfer energies E-CT of Yb3+ and Sm3+ and environmental factors h(e) in various crystals was investigated using a dielectric chemical bond method. Both results show that they have an exponential relation E-CT = A+B exp(-kh(e)), but the exponential factors are different, which indicates that the interaction between the rare earth ions and environment is connected with the kind of rare earth ion. This result provides a method of determining charge transfer energies of Yb3+ and Sm3+ from a crystal structure.

Structural and Bluish-White Luminescent Properties of Li+-Doped BPO4 as a Potential Environmentally Friendly Phosphor Material

Many efforts have been devoted to exploring novel luminescent materials that not contain expensive or toxic elements, or do not need a mercury vapor plasma source. In this paper, BPO4 and Li+-doped BPO4 powder samples were prepared by the Pechini-type sol-gel (PSG) process. The structure and optical properties of the resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), photoluminescence (PL) excitation and emission spectra, kinetic decay, and X-ray photoelectron spectra (XPS), respectively. It was found that PSG -derived Li+-doped BPO4 annealed at 960 degrees C exhibited bright bluish-white emission centered at 416 nm. The luminescence decay curves analysis indicates that each sample has two kinds of lifetimes (5.9 ns and 0.529 ms) and two types of kinetic decay behaviors which can be fitted into a single-exponential function and a double-exponential function, respectively.

Autophobic Dewetting of a Poly(methyl methacrylate) Thin Film on a Silicon Wafer Treated in Good Solvent Vapor

The wettability of thin poly(methyl methacrylate) (PMMA) films on a silicon wafer with a native oxide layer exposed to solvent vapors is dependent on the solvent properties. In the nonsolvent vapor, the film spread on the substrate with some protrusions generated on the film surface. In the good solvent vapor, dewetting happened. A new interface formed between the anchored PMMA chains and the swollen upper part of the film. Entropy effects caused the upper movable chains to dewet on the anchored chains. The rim instability depended on the surface tension of solvent (i.e., the finger was generated in acetone vapor (gamma(acetone) = 24 mN/m), not in dioxane vapor (gamma(dioxane) = 33 mN/m)). The spacing (lambda) that grew as an exponential function of film thickness h scaled as similar to h(1.31) whereas the mean size (D) of the resulting droplets grew linearly with h.

Enhanced luminescence of BPO4 by mixing with SiO2 and Al2O3

In this paper, BPO4-xSiO(2) (X: SiO2/BPO4 molar ratio, 0-70%) and BPO4-xAl(2)O(3) (X: Al2O3/BPO4 molar ratio, 0-20%) powder samples were prepared by the Pechini-type sol-gel (PSG) process using glycerol and poly(ethylene glycol) as additives. The structure and optical properties of the resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), diffuse reflection spectra, photoluminescence (PL) excitation and emission spectra, kinetic decay, and X-ray photoelectron spectra (XPS), respectively. It was found that the Pechini-type sol-gel-derived BPO4-xSiO(2) annealed at 1000 degrees C and BPO4-xAl(2)O(3) annealed at 960 degrees C exhibited bright bluish-white emissions centered at 428 and 413 nm, respectively. The luminescence decay curve analysis indicates that each sample has two kinds of lifetimes (more than 0.4 ms and less than 10 ns) and two types of kinetic decay behaviors, which can be fitted into a double-exponential function and a single-exponential function, respectively.

Layer-by-Layer Buildup of Poly(L-glutamic acid)/Chitosan Film for Biologically Active Coating

A new biocompatible film based on chitosan and poly(L-glutamic acid) (CS/PGA), created by alternate deposition of CS and PGA, was investigated. FT-IR spectroscopy, UV-vis spectroscopy and QCM were used to analyze the build-up process. The growth of CS and PGA deposition are both exponential to the deposition steps at first. After about 9 (CS/PGA) depositions, the exponential to linear transition takes place. QCM measurements combined with UV-vis spectra revealed the increase in the multilayer film growth at different pH (4.4, 5.0 and 5.5). The build-up of the multilayer stops after a few depositions at pH = 6.5. A muscle myoblast cell (C2C12) assay showed that (CS/PGA)(n) multilayer films obviously promote C2C12 attachment and growth.

Incorporation of Nanoparticles into Polyelectrolyte Multilayers via Counterion Exchange and in situ Reduction

We report a general method for incorporation of nanoparticles into polyelectrolyte multilayer (PEM) thin films by utilizing the excess charges and associated counterions present in the PEMs. Silver ions were introduced directly into multilayers assembled from poly(diallyldimethylammonium chloride) (PDDA) and poly(styrene sulfonate) (PSS), (PDDA/PSS)(n), by a rapid ion exchange process, which were then converted into silver nanoparticles via in situ reduction to create composite thin films. The size and the content of the nanoparticles in the film call be tuned by adjusting the ionic strength in the polyelectrolyte solutions used for the assembly. Spatial control over the distribution of the nanoparticles in the PEM was achieved via the use of multilayer heterostructure containing PDDA/PSS bilayer blocks assembled at different salt concentrations. Because excess charges and counterions are always present in any PEM, this approach can be applied to fabricate a wide variety of composite thin Films based on electrostatic self-assembly.

Kinetics and Statistical Distributions of Single-Molecule Conformational Dynamics

We developed a coarse-grained yet microscopic detailed model to study the statistical fluctuations of single-molecule protein conformational dynamics of adenylate kinase. We explored the underlying conformational energy landscape and found that the system has two basins of attractions, open and closed conformations connected by two separate pathways. The kinetics is found to be nonexponential, consistent with single-molecule conformational dynamics experiments. Furthermore, we found that the statistical distribution of the kinetic times for the conformational transition has a long power law tail, reflecting the exponential density of state of the underlying landscape. We also studied the joint distribution of the two pathways and found memory effects.

Downhill kinetics of biomolecular interface binding: Globally connected scenario

We study the kinetics of the biomolecular binding process at the interface using energy landscape theory. The global kinetic connectivity case is considered for a downhill funneled energy landscape. By solving the kinetic master equation, the kinetic time for binding is obtained and shown to have a U-shape curve-dependence on the temperature. The kinetic minimum of the binding time monotonically decreases when the ratio of the underlying energy gap between native state and average non-native states versus the roughness or the fluctuations of the landscape increases. At intermediate temperatures,fluctuations measured by the higher moments of the binding time lead to non-Poissonian, non-exponential kinetics. At both high and very low temperatures, the kinetics is nearly Poissonian and exponential.

The complex kinetics of protein folding in wide temperature ranges

The complex protein folding kinetics in wide temperature ranges is studied through diffusive dynamics on the underlying energy landscape. The well-known kinetic chevron rollover behavior is recovered from the mean first passage time, with the U-shape dependence on temperature. The fastest folding temperature T-0 is found to be smaller than the folding transition temperature T-f. We found that the fluctuations of the kinetics through the distribution of first passage time show rather universal behavior, from high-temperature exponential Poissonian kinetics to the relatively low-temperature highly nonexponential kinetics. The transition temperature is at T-k and T-0, T-k, T-f. In certain low-temperature regimes, a power law behavior at long time emerges. At very low temperatures ( lower than trapping transition temperature T< T-0/(4&SIM;6)), the kinetics is an exponential Poissonian process again.