渐近稳定性定理的推广

本文讨论了较一般的非线性微分方程组零解的渐近稳定性，推广了文［１］及文［２］的证明方法和其中的一些结果．特别是去掉了Ｌｉａｐｕｎｏｖ函数具有无穷小上界的条件。最后举例说明作者所得的新结果有效且优于前人的有关结果．     

Determination of the dynamical behaviour of biological materials during impact using a pendulum device

A pendulum device has been developed to measure contact force, displacement and displacement rate of an impactor during its impact on the sample. Displacement, classically measured by double integration of an accelerometer, was determined in an alternative way using a more accurate incremental optical encoder. The parameters of the Kuwabara-Kono contact force model for impact of spheres have been estimated using an optimization method, taking the experimentally measured displacement, displacement rate and contact force into account. The accuracy of the method was verified using a rubber ball. Contact force parameters for the Kuwabara-Kono model have been estimated with success for three biological materials, i.e., apples, tomatoes and potatoes. The variability in the parameter estimations for the biological materials was quite high and can be explained by geometric differences (radius of curvature) and by biological variation of mechanical tissue properties.     

SYNTHESIS OF 1,2-ACEANTHRYLENEDIONE THROUGH ACYLATION OF ANTHRACENE WITH OXALYL CHLORIDE

Acylation of anthracene and oxalyl chloride in the presence of anhydrous AlCl3 was investigated. Pure 1,2-aceanthrylenedione, which is used as new functional macromolecule, was prepared by extraction and recrystallation. The structure of 1,2-aceanthrylenedione was identified by measure of melting point, GC/MS, FTIR and 1↑HNMR analyses. The influences of various parameters, such as solvent, dosage of catalyst, molar ratio of anthracene to oxalyl chloride, reaction temperature, and reaction time were studied. The anhydrous AlCl3 was found to catalyze the reaction with high yeild and good selectivity. When the reaction temperature is 303K, reaction time is 5h and molar ratio of anthracene to oxalyl chloride is 1：2, the yield and selectivity of 1,2-aceanthrylenedione is 83.8 % and 92.3% respectively.     

Isomerisierung von (all-E)-Cycloviolaxanthin Herstellung und Charakterisierung von (9Z)-und (13Z)-Cycloviolaxanthin

Isomerization of (all-E)-Cycloviolaxanthin. Preparation and Characterization of (9Z)- and (13Z)-Cycloviolaxanthin From (all-E)-cycloviolaxanthin (ex Capsicum annuum), (9Z)- and (13Z)-cycloviolaxanthin were prepared in a highly pure state. The configuration of both isomers was determined by means of UV/VIS, NMR, and CD spectroscopy.     

Anion-/cation-directed reaction routes to polymorphic forms of a pyrazole-type ligand and its coordination compounds with zinc. Key structural differences between polymorphs’

Synthetic paths toward the two polymorphs of a monohydrate, one anhydrous polymorph of 1-carboxamidino-5-hydroxy-3-methylpyrazole (hcmp) and two polymorphs of zinc complexes containing hcmp ligand are presented. By choosing ions which are not part of the final product, it is possible to direct the synthesis toward the particular polymorph. In all three modifications of hcmp, the same hydrogen bonding motif appears, leading to formation of similar molecular chains. Differences arise due to different modes of chain aggregation and the presence of solvent water. Analysis of the crystal packing and the energetic features of hcmp polymorphs is made using the PIXEL model. The thermal decomposition processes are examined using differential scanning calorimetry and thermogravimetry. Analysis of crystal packing in the two polymorphs of zinc complex suggests the key role of the hydrogen bonding capacity of the aqua ligand for the appearance of the two polymorphic forms. In both polymorphs of zinc complex, stacking interactions have an important role. However, the enhanced hydrogen bonding capacity of the aqua ligand influences the formation of multistacking arrangement.     

Binding interaction analysis of the active site and its inhibitors for neuraminidase (N1 subtype) of human influenza virus by the integration of molecular docking, FMO calculation and 3D-QSAR CoMFA modeling

Recently, the worldwide spread of A/H5N1 avian influenza with high virulence has highlighted the potential threat of human influenza pandemic. Tamiflu and Relenza are currently the only two anti-influenza drugs targeting the neuraminidase (NA) enzyme of human influenza virus. Reports of the emergence of drug resistance further make the development of new potent anti-influenza inhibitors a priority. The X-ray crystallographic study of A/H5N1 avian influenza NA subtypes (Russell, R. J. Nature 2006, 443, 45-49) has demonstrated that there exist two genetically distinct groups, group-1 (N1, N4, N5 and N8) and group-2 (N2, N3, N6, N7 and N9), whose conformations are substantially different. The detailed comparison of their active sites has established, heretofore, the most accurate and solid molecular basis of structure and mechanism for the development of new anti-influenza drugs. In the present study, a three-dimensional structure of N1 subtype of human influenza type A virus (N1hA) has been generated by homology modeling using the X-ray crystallographic structure of N1 subtype of avian influenza virus (N1aA) as the template. Binding interaction analysis between the active site and its inhibitors has been performed by combining ab initio fragment molecular orbital (FMO) calculations and three-dimensional quantitative structure-activity relationship with comparative molecular field analysis (3D-QSAR CoMFA) modeling. Integrated with docking-based 3D-QSAR CoMFA modeling, molecular surface property (electrostatic and steric) mapping and FMO pair interaction analysis, a set of new receptor-ligand binding models and bioaffinity predictive models for rational design and virtual screening of more potent inhibitors of N1hA are established. In addition, the flexibility of the loop-150 of N1hA and N1aA has been examined by a series of molecular dynamics simulations.     

Fabrication of controllable graphene aerogel with superior adsorption capacity for organic solvents

Controllable graphene aerogel with relative homopores was fabricated with the assistance of block copolymer (P123) and vacuum drying. Thermogravimetric analysis was conducted to obtain the optimum temperature for template removal. The Brunauer–Emmett–Teller method, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction were performed to characterise the obtained aerogel. Results showed that P123 was successfully removed on the surface, and a controlled multi-level porous structure was generated. The optimum ratio of GO and P123 was 1:4 (ca. 2.5 mg/ml), and the adsorption capacities of the produced aerogels for methylene blue, oils and organic solvents were excellent and superior to those aerogels fabricated by traditional approaches. Adsorption kinetics were also further studied.     

CoH生成热力学函数的量子力学计算

用B3LYP/SDD密度泛函方法计算了CoH的微观性质、CoH(g)、CoD(g)和CoT(g)的能量(E)和熵(S),进而计算Co与H2、D2、T2反应的△H(-)、△G(-)、△S(-).CoH分子的基电子状态为三重态,Re、D(-)0、ωe分别为1.52nm、277.84 kJ/mol和1321 cm-1,与实验值基本一致.在固态分子的E和S的计算中,以气态分子计算得到的总能量中的振动能Ev代替固态能量,以总熵中的电子振动熵SEv代替固态熵.导出了Co与氢同位素气体反应的△H(-)、△G(-)、△S(-)及平衡氢压力与温度的关系.CoH的室温下平衡离解压力很低,表明CoH是一种稳定的氢化物,这与CoH分子的D(-)0很大的实验事实一致.     

A noncooperative power control game in multi-access fading channels with quality of service (QoS) constraints

In this paper, a game-theoretic analysis for the resource allocation policies in fading multiple-access channels (MACs) in the presence of statistical quality of service (QoS) constraints in the form of limitations on the buffer length is performed. We employ effective capacity, which provides the maximum constant arrival rate that a given process can support while satisfying statistical buffer constraints, to measure the throughput for each user. We assume that the channel side information (CSI) is available at both the receiver and the transmitters, and the transmitters are selfish, rational with certain QoS and average power constraints. Without the aid of the receiver, we show that there is always a unique admissible Nash equilibrium of the noncooperative power control game, for which numerical results at low signal-to-noise ratios (SNRs) have been provided. The Nash equilibrium of the power control game is proved to be always inside the rate region where successive decoding techniques are used at the receiver.     

Introduction of click chemistry to carotenoids

We describe the synthesis of carotenoid derivatives via the azide–alkyne click reaction and optimize the conditions for these sensitive molecules. After finding the mildest conditions possible for the reaction we were able to use the click reaction for the synthesis of PEG–carotenoid conjugates starting from carotenoid pentynoates and PEG azides.