浅谈电力工程施工中的质量管理

电力工程施工质量管理是企业决策者和广大安全工作者都要思考的一个问题,且直接关系到电力施工企业的生存发展,本文浅谈影响电力工程质量的主要因素,并提出电力工程施工中的质量控制措施。     

Sequence similarity analysis of non-self CTL epitopes and mouse proteins using sequence alignment

This research analyzed amino acid sequence similarity between non-self T cell epitopes recognized by mouse antibodies and mouse proteins. Using sequence alignment,we found that only 8 of 1 108 epitopes are highly similar to mouse protein sequences. The result shows that non-self T cell epitopes are not similar or have little similarity to mouse protein sequences. Furthermore,reviewing the related literature,we also found that the eight epitopes would trigger immune responses in some particular environment,which are ignored by T cells in normal condition. The result suggests that no or low-similarity peptide vaccines can reduce the chance of collateral cross-reactions and enhance the antigen-specific immune response to vaccine.     

Photocatalytic activity of TiO<Subscript>2</Subscript> sensitized by CdS quantum dots under visible-light irradiation

In this paper, CdS quantum dots sensitized TiO2 composite powders (QD-CdS/TiO2) were synthesized by impregnating TiO2 powder into CdS sol with different concentrations. X-ray diffraction pattern (XRD) shows the crystal structures of CdS and TiO2 are cubic phase and anatase phase separately in QD- CdS/TiO2 powder samples; the crystal size of CdS in QD- CdS/TiO2 is about 3-7 nm, while TiO2 crystal size is about 20 nm. With increasing CdS content in QD-CdS/TiO2 composite, the UV-Vis absorption spectrum shifted to the longer wavelength lines, exhibiting obvious quantum size effect. The fluorescence intensity of QD-CdS/TiO2 irradiated by blue light is weaker than that of pure CdS. When the molar ratio of CdS and TiO2 is about 1∶2, the QD-CdS/TiO2 powder has the best catalytic properties under visible-light irradiation, and the degradation rate of rhodamine B (RhB) is up to 92.2% within 60 min.     

Coordinating production and recycling decisions with stochastic demand and return

In this paper, the joint production and recycling problem is investigated for a hybrid manufacturing and remanufacturing system where brand-new products are produced in the manufacturing plant and recycled products are remanufactured into as-new products in the remanufacturing facility. Both the brand-new products and remanufactured products are used to satisfy customer demands. Returns of used products that are recycled from customers are assumed to be stochastic and nonlinearly price-dependent. A mathematical model is proposed to maximize the overall profit of the system through simultaneously optimizing the production and recycling decisions, subject to two capacity constraints — the manufacturing capacity and the remanufacturing capacity. Based on Lagrangian relaxation method, subgradient algorithm and heuristic algorithm, a solution approach is developed to solve the problem. A representative example is presented to illustrate the system, and managerial analysis indicates that the uncertainties in demand and return have much influence on the production and recycling policy. In addition, twenty randomly produced examples are solved, and computational results show that the solution approach can obtain very good solutions for all examples in reasonable time.     

Learnability of multi-instance multi-label learning

Multi-instance multi-label learning(MIML) is a new machine learning framework where one data object is described by multiple instances and associated with multiple class labels.During the past few years,many MIML algorithms have been developed and many applications have been described.However,there lacks theoretical exploration to the learnability of MIML.In this paper,through proving a generalization bound for multi-instance single-label learner and viewing MIML as a number of multi-instance single-label learning subtasks with the correlation among the labels,we show that the MIML hypothesis class constructed from a multi-instance single-label hypothesis class is PAC-learnable.     

Hydrothermal synthesis and photoluminescence behavior of CeO<Subscript>2</Subscript> nanowires with the aid of surfactant PVP

Well-crystalline CeO₂ nanowires were prepared via a surfactant-assisted hydrothermal process. Reaction temperature and reaction time were changed for the determination of optimal synthesis parameters. The as-obtained products were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and field emission scanning electron microscopy (FESEM). The results show that single crystal CeO₂ nanowires with high yield and good uniformity can be obtained hydrothermally at 180°C for 12 h with the aid of 2.0 g surfactant (polyvinyl pyrrolidone, PVP). The role of PVP was then discussed and a possible growth mechanism was proposed. Moreover, room temperature photoluminescence (PL) spectra were obtained for these CeO₂ nanowires, which are believed to be related to the abundant defects in these nanostructures.     

Biomimetic fluorapatite films for conservation of historic calcareous stones

Fluorapatite protective films were prepared on marble substrates using a biomimetic method. By mimicking the mineralization mechanism of enamel, phosphorus and fluorine were introduced on the surface of the marble substrate. In the presence of a biological template, namely collagen, an integrated fluorapatite film was produced and the marble substrate was entirely covered. The prepared fluorapatite films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The performances of the fluorapatite films were evaluated by color changes, capillary water absorption, and acid resistance tests. The results revealed that the fluorapatite films had good compatibility with the marble substrate; the physical properties such as color and capillary water adsorption of the marble substrates were unchanged. The fluorapatite films also had good acid resistance and were stable even in heavy acid rain.     

A numerical method to simulate the coupled oscillations of flexible structures in flowing fluids

A numerical method is developed to simulate the coupled phenomena in a fluid-flexible-structure system. Specifically, a two-dimensional panel method is used to calculate the hydrodynamic forces and a modal superposition method is adopted to solve the governing equation of an Eulerian beam. The stability boundary of a single flexible beam in a uniform flow is calculated and compared with previous results to verify the validity of the code. The flow-induced flapping of a single and two flexible bodies for S=1.0, U*=7.0 are investigated. For the flow-induced vibration of a single beam, the oscillation frequency is close to the secondary natural frequency of a cantilever. For two parallel flexible beams, they oscillate in phase when the non-dimensional separating distance H<0.25. When H>0.25, the out-of-phase mode occurs with a jump in frequency. When H>1, the interaction between the two beams decouples and the frequency and forces of each beam revert to behavior associated with a single beam in the same flow. Simulations of coupled-flapping of two tandem flexible structures proved that the drag acting on the upstream body is reduced while for that downstream drag is obviously increased when the structures are closely arranged. The numerical results obtained in the present work are qualitatively consistent with early experimental results.     

Radioprotectors from pyrodextrins

Cornstarch heated in the range of 230–280°C depolymerized into pyrodextrins characterized by two-component EPR signals of relatively stable free radicals. These thermally generated radicals could serve as efficient scavengers for free radicals generated from pyrodextrins with the 200 Gy dose of γ-radiation. The most efficient traps/scavengers were produced from cornstarch at 250–280°C. IR data indicated incorporation of the OH groups to the pyrodextrins. These groups most probably originated from the OH· radicals formed by the radiolysis of water. EPR spectra provided evidence for trapping free radicals generated by γ-irradiation and for their subsequent annihilation on contact with pyrodextrins. Water affected radical processes occurring in pyrodextrins caused by γ-irradiation.     

Automatic identification of use cases from codes: A user’s goal driven approach

Based on the different roles played by base flow and alternative flow in the process to achieve user’s goals, we have found that loop structure is frequently used to implement alternative flow and/or to connect different use cases. This paper presents an approach to identify base flows and alternative flows of different use cases by traversing control flow graph in which back edges are eliminated. The effectiveness of the approach is verified by identification of the use case structure of an ATM system. The workload of human intervention of the approach is relatively slight, and the manner of human intervention closely follows the usual process of software comprehension.