非线性项有非线性增长的高阶多点边值问题

本文考虑以下高阶多点边值问题：，其中关于f有非线性增长的情况，利用基于度理论的不动点定理，对上述边值问题建立了存在唯一性定理．     

多元凸函数的一个定理

本文在［１］的基础上．给出了与多元函数中值定理结论类似的一个定理．     

On tertiary exotic characteristic classes

We prove the existence and nontriviality of tertiary exotic characteristic classes extending the results of Peterson and Ravenel for secondary exotic classes.

     

Phase-resolved detection in ion-mobility spectrometry

Throughput has been improved in an ion-mobility spectrometer by means of continuous ion-beam modulation and phase-resolved detection. Conventional ion-mobility spectrometry (IMS) utilizes brief packets of ions for separation in the gas phase. In contrast, this preliminary report outlines a new detection method based on phase resolution and involves monitoring the ion signal continuously, which raises the duty cycle of the instrument from approximately 1% (conventional IMS) to 50%. The greater duty cycle is shown to improve signal-to-noise ratios (S/N). However, the higher S/N levels did not translate into higher sensitivity values when calibration plots were constructed. It is demonstrated that even analytes with small differences in drift times can be modulated at frequencies that maximize the measured phase differences between ions. Phase-resolved signals can be processed with a Fourier transform and chemometric data reduction to simplify identification of the analyte from its phase spectra.     

Cu/Mn/ZrO2 catalyst for alcohol synthesis by Fischer-Tropsch modified elements

A Cu/Mn/ZrO₂ methanol synthesis catalyst modified by Fischer-Tropsch (F-T) element (Ni,Co,Fe) was prepared by an coprecipatation method. The addition of F-T elements had a great effect on the catalyst performance. The higher alcohol selectivity increased greatly compared with that of the Cu/Mn/ZrO₂ catalyst when nickel and cobalt were added, while the addition of iron improved the selectivity tohydrocarbon due to the interaction of the F-T element and the Cu/Mn/ZrO₂ catalyst.     

CoCuY催化体系上MoOx的助剂作用和协同效应的研究

在6MPa的条件下合成气反应的结果表明,为了获得良好的混合醇产率和选择性,铜、钴和钼的协同并存是重要的.CoCuY催化剂上MoO_x的加入显著提高了甲醇和高级醇的产率.在280℃的反应温度下,获得了175g/kg cat/h的混合醇产率,内含45wt%的高级醇.在Mo/CoCuY催化剂中,钴、铜和钼的氧化物之间具有强的相互作用和协同还原效应.XRD的结果表明,在合成气反应中助剂MoO_x的存在稳定了催化剂中的Y_2O_3晶相结构,减少了其无定形分散.     

Building carbohydrates on the dioxanone scaffold: stereoselective synthesis of d-glycero-d-manno-2-octulose

The title compound has been synthesized via two proline-catalyzed aldol addition reactions of 2,2-dialkyl-1,3-dioxan-5-ones: the first addition to 1,3-dithiane-2-carboxaldehyde, followed by reduction to the corresponding diol, protection of the OH groups and dithiane hydrolysis afforded a protected d-ribose that was used in the second aldol addition reaction.     

Evaluating the third and fourth derivatives of spectral data

The problem of differentiating spectral data to yield the third and fourth derivatives is converted into one of solving an integral equation of the first kind. This equation is solved by Tikhonov regularization. The method of General Cross Validation is used to guide the choice of the regularization parameter that keeps noise amplification under control. The performance of this route to third and fourth derivative spectra is demonstrated by applying it to a number of published spectra. A computational problem associated with General Cross Validation has been identified.     

Poly(ethylene oxide) facilitates the characterization of an affinity between strongly basic proteins with DNA by affinity capillary electrophoresis

In order to study kin17 protein-DNA affinity, we have developed a fast and reproducible capillary electrophoresis (CE) analysis of a strongly basic protein: kin17 protein, using a nonpermanent coating based on poly(ethylene oxide) (PEO) to avoid adsorption of kin17. The coating procedure was optimized to provide a residual and stable electroosmotic flow (EOF = 5 x 10(-5) cm(2)/V x s), exhibiting RSD of 0.3% and excellent long-term stability. Good intraday and interday reproducibility of kin17 migration times (0.8 and 0.3% relative standard deviation (RSD), respectively) enabled us to consider that the recovery percentage obtained for kin17 protein was satisfactory (79%). The potential of this PEO-based coating procedure was evaluated for affinity CE method in order to study the affinity of kin17 protein for two single-stranded DNA (ssDNA) models: polydeoxyadenylic acid and polydeoxycytidilic acid (pdA and pdC). Binding constants (1.5 x 10(7) +/- 17% and 1.7 x 10(7) + 25%M(-1)) were evaluated assuming a 1:1 affinity between kin17 and pdA or pdC, respectively.