Cohomology theories in triangulated categories

Let C be a triangulated category with a proper class E of triangles.We prove that there exists an Avramov–Martsinkovsky type exact sequence in C,which connects E-cohomology,E-Tate cohomology and E-Gorenstein cohomology.     

Unconditional uniqueness of solution for $$\dot H^{s_c }$$ critical 4th order NLS in high dimensions

In this paper, we study the unconditional uniqueness of solution for the Cauchy problem of Ḣ^s_c(0 ≤ s_c < 2) critical nonlinear fourth-order Schrödinger equations i∂_tu + Δ²u-εu=λ|u|^αu. By employing paraproduct estimates and Strichartz estimates, we prove that unconditional uniqueness of solution holds in C_t(I; Ḣ^s_c(R^d)) for d ≥ 11 and min{1^-, (8)/(d-4)} ≥ α >(-(d-4)+√4(d-4)²+64)/4.     

On the Characterization of Maximal Planar Graphs with a Given Signed Cycle Domination Number

Let G =(V, E) be a simple graph. A function f : E → {+1,-1} is called a signed cycle domination function(SCDF) of G if ∑_(e∈E(C))f(e) ≥ 1 for every induced cycle C of G. The signed cycle domination number of G is defined as γ'_(sc)(G) = min{∑_(e∈E)f(e)| f is an SCDF of G}. This paper will characterize all maximal planar graphs G with order n ≥ 6 and γ'_(sc)(G) = n.     

Interaction between water-soluble peptidic CdSe/ZnS nanocrystals and membranes: formation of hybrid vesicles and condensed lamellar phases

Due to their tunable optical properties and their well-defined nanometric size, core/shell nanocrystals (quantum dots, QDs) are extensively used for the design of biomarkers as well as for the preparation of nanostructured hybrid materials. It is thus of great interest to understand their interaction with soft lipidic membranes. Here we present the synthesis of water-soluble peptide CdSe/ZnS QDs and their interaction with the fluid lipidic membrane of vesicles. The use of short peptides results in the formation of small QDs presenting both high fluorescence quantum yield and high colloidal stability as well as a mean hydrodynamical diameter of 10 nm. Their interaction with oppositely charged vesicles of various surface charge and size results in the formation of hybrid giant or large unilamellar vesicles covered with a densely packed layer of QDs without any vesicle rupture, as demonstrated by fluorescence resonance energy transfer experiments, zetametry, and optical microscopy. The adhesion of nanocrystals onto the vesicle membrane appears to be sterically limited and induces the reversion of the surface charge of the vesicles. Therefore, their interaction with small unilamellar vesicles induces the formation of a well-defined lamellar hybrid condensed phase in which the QDs are densely packed in the plane of the layers, as shown by freeze-fracture electron microscopy and small-angle X-ray scattering. In this structure, strong undulations of the bilayer maximize the electrostatic interaction between the QDs and the bilayers, as previously observed in the case of DNA polyelectrolytes interacting with small vesicles.     

Highly efficient heterogeneous procedure for the synthesis of fructone fragrancy

A novel heterogeneous strong acid catalyst was synthesized through the copolymerization of p-toluenesulfonic acid and paraformaldehyde and utilized for the synthesis of fructone. The results showed that the catalyst was very efficient for the reaction with the yield over 95%. The advantages of extremely high density of acidity, high thermal and chemical stability, low cost for the simple synthetic procedure, and reusability made the catalyst one of the best choices for the reaction.     

Lamellar metal-organic complex and its rod-like nanoparticles prepared with ultrasonic technique

Metal-organic complex (H3NCH2CH2NH2)3[MoO2(OC6H4O)2] with a lamellar morphology has been syn- thesized. Its crystal structure was confirmed by single-crystal X-ray diffraction. The morphology of the crystal was observed by scanning electron microscopy (SEM). The metal-organic nanoparticles have been prepared by using an ultrasonic method. The morphology of the as-prepared nanoparticles was observed by transmission electron microscopy (TEM). The possible formation mechanism has also been proposed.     

Matrix-assisted pulsed laser evaporation of polyimide thin films and the XPS study

Compared with the traditional thin film techniques, the matrix-assisted pulsed laser evaporation (MAPLE) technique has many advantages in the deposition of polymer and organic thin films. It has a wide range of applications in many fields, such as non-linear optics, luminescent devices, electronics, various sensors. We have successfully deposited polyimide thin films by using the MAPLE technique. These films were characterized with XPS. The XPS spectra showed that the single-photon effect is ob-vious at low laser fluence and the chemical bonds will be broken, resulting in decomposition of the films. Contrarily, the single-photon effect will decrease and the multi-photon effect and the photothermal effect will increase at high laser fluence, resulting in the protection of the structure of the polyimide thin films and the obvious decrease in decomposition. High laser fluence is more suitable for the deposition of polymer and organic thin films than low laser fluence.     

The effect of substrate concentration on biohydrogen production by using kinetic models

The effect of substrate concentration ranging from 0 to 300 g/L on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35℃ and initial pH 7.0, during the fermentative hydrogen production, the hydrogen production potential and hydrogen production rate increased with increasing substrate concentration from 0 to 25 g/L. The maximal hydrogen production potential of 426.8 mL and maximal hydrogen pro-duction rate of 15.1 mL/h were obtained at the substrate concentration of 25 g/L. The maximal hydrogen yield and the maximal substrate degradation efficiency were respectively 384.3 mL/g glucose and 97.6%, at the substrate concentration of 2 g/L. The modified Logistic model could be used to describe the progress of cumulative hydrogen production in this study successfully. The Han-Levenspiel model could be used to describe the effect of substrate concentration on fermentative hydrogen production rate.     

The anharmonic effect study of coupled Morse oscillators for the unimolecular reaction

The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF) Morse oscillator (MO) potential on unimolecular reaction. We shall use the systematic theoretical approach, YL method, proposed by Yao and Lin (YAO L, et. al. J Phys Chem A, 2007, 111(29): 6722-6729), which can evaluate anharmonic effects on the rate constants based on the transition state theory. In treating the anharmonic effect with the Morse oscillator potential on unimolecular reactions under collision-free conditions by using the RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the in-verse Laplace transformation of the partition functions was used to obtain the total amount of state and density of state by using the first-order and the second-order approximations of the saddle-point method. To demonstrate the anharmonic effect of the SBF Morse model, we choose some model systems and a real reaction as examples.     

An amperometric sensor for uric acid based on ordered mesoporous carbon-modified pyrolytic graphite electrode

A novel amperometric sensor for uric acid based on ordered mesoporous carbon modified pyrolytic graphite electrode was developed. Uric acid oxidation was easily catalyzed by this electrode in a phosphate buffer solution at pH 7.0, with an anodic potential decrease about 140 mV compared to bare pyrolytic graphite electrode. The uric acid level was determined by the amperometric method, at a constant potential of 0.31 mV, the catalytic current of uric acid vs. its concentration showed a good linearity in the range of 1.0 × 10⁻⁶−1.0 × 10⁻⁴ mol L⁻¹, with a correlation coefficient of 0.999. The detection limit was 4.0 × 10⁻⁷ mol L⁻¹. The proposed method could be effectively used for uric acid amperometric sensing in human urine.