基于差示扫描量热法的火工品材料选型研究

通过综合分析差示扫描量热法(DSC)图谱及动力学数据,进行火工品中药剂外包覆材料的选型研究。采用DSC测试炸药与不同涂敷层材料在不同升温速率的热性质,利用Ozawa法和DSC曲线对比法,对几种涂敷层材料进行分析。炸药与丙烯酸清漆混合后,DSC曲线表观性征、峰温以及反应的活化能变化最小;炸药与快速固化剂混合后,峰温及活化能变化影响居中,DSC曲线表观性征在升温速率大时有较大变化;炸药与硅橡胶混合后,DSC曲线表观性征、峰温以及反应的活化能变化最大。从而确定丙烯酸清漆为最合适的炸药包覆材料。     

基于VHSE结构表征的TAP亲和活性预测及选择特异性分析

应用氨基酸描述子VHSE(Principal component score vector of hydrophobic, steric, and electronic properties)对613个抗原9肽进行结构表征, 在此基础上, 采用支持向量机结合逐步回归变量筛选方法, 成功建立了抗原肽抗原处理相关转运蛋白(Transporter associated with antigen processing, TAP)亲和活性预测模型, 最优线性支持向量机模型的R2, Q2和R2ext分别为0.7386, 0.7270和0.6057. 模型结果分析表明, 影响TAP亲和活性的首要因素是电性, 其次是立体和疏水性质; 底物9肽的P1(N端)及P2, P7和P9(C端)位氨基酸物化性质对TAP亲和活性有重要影响, 而P3, P4, P5和P6位对模型贡献相对较小, P8位则与活性无关. 依据最优模型对模拟点突变9肽的TAP亲和活性的预测结果, 并结合变量载荷分析, 对TAP底物选择特异性进行了分析和总结.     

The Sharkovski? Theorem for spaces of measurable functions

We formulate a generalization of the so-called Random Sharkovski? Theorem from paper by Jan Andres, which is the randomized version of the classical Sharkovski? Theorem. We use the method of transformation to deterministic case involving the Kuratowski-Ryll-Nardzewski selection theorem, which allows us to omit the assumption of completeness of the incorporated measurable space. Moreover, we formulate an analogue of the Sharkovski? Theorem for spaces of measurable functions and for Lp-spaces.     

The effects of a new selection operator on the performance of a genetic algorithm

In this study, the new back controlled (BCSO) selection operator for genetic algorithm (GA) is presented. In the first stage, six existing operators and the BCSO were applied to the traveling salesman and space truss benchmark problems. An analysis of the results of the benchmark problems was made for each of the seven selection operators. In the second stage, the BCSO, the Roulette Wheel, dominant selection the hybrid II and operators were used to determine the fittest beam section has been used. In this stage, the cost of beam for a 18.3 m span developed by Mid-Atlantic States Pre-stressed Concrete Committee for Economic Fabrication and using a genetic algorithm the cost of a beam using BCSO were compared. It was determined that the beam produced using the proposed BCSO selection operator would be lower than those obtained with the existing selection operators. Also the determined beam cost is compares favourably with the average cost of a beam sold by the precast industry in the USA.     

Protograph bit-interleaved coded modulation: A bandwidth-efficient design paradigm for 6G wireless communications

Bit-interleaved coded modulation (BICM) has attracted considerable attention from the research community in the past three decades, because it can achieve desirable error performance with relatively low implementation complexity for a large number of communication and storage systems. By exploiting the iterative demapping and decoding (ID), the BICM is able to approach capacity limits of coded modulation over various channels. In recent years, protograph low-density parity-check (PLDPC) codes and their spatially-coupled (SC) variants have emerged to be a pragmatic forward-error-correction (FEC) solution for BICM systems due to their tremendous error-correction capability and simple structures, and found widespread applications such as deep-space communication, satellite communication, wireless communication, optical communication, and data storage. This article offers a comprehensive survey on the state-of-the-art development of PLDPC-BICM and its innovative SC variants over a variety of channel models, e.g., additive white Gaussian noise (AWGN) channels, fading channels, Poisson pulse position modulation (PPM) channels, and flash-memory channels. Of particular interest is code construction, constellation shaping, as well as bit-mapper design, where the receiver is formulated as a serially-concatenated decoding framework consisting of a soft-decision demapper and a belief-propagation decoder. Finally, several promising research directions are discussed, which have not been adequately addressed in the current literature.     

Nonparametric Approach to Analysis of Space-Time Data on Earthquake Occurrences

Abstract

As an alternative to traditional, parametric approaches, we suggest nonparametric methods for analyzing spatial and temporal data on earthquake occurrences. Nonparametric techniques are particularly adaptive to anomalous behavior in the data and provide a new way of accessing a variety of different types of information about the way in which both intensity and magnitude of events evolve in time. They can be employed to estimate the spatial trajectory of event clusters as a function of time, and to define quiescent and active periods. The latter application suggests new approaches to forecasting high magnitude events. Our methods are founded on multivariate techniques for curve and surface estimation, particularly in contexts where curves or surfaces are unbounded at points or along lines.     

Structure and magnetic properties of LaFe11.5−xCoxSi1.5C0.2 compounds for magnetic refrigeration near room temperature

The influence of cobalt on the microstructural, magnetic and magnetocaloric properties of LaFe_11.5−xCo_xSi_1.5C_0.2 (x=0.50–0.85) compounds was investigated. The ingots were prepared by using a vacuum induction melting furnace. Before annealing, a large amount of 1:13 phase was distinctly observed. Nearly single 1:13 phase was obtained after annealing at 1353 K for only 3 days. The easy formation of 1:13 phase in the annealing process could be attributed to carbon doping. The Curie temperature (T_C) increases linearly with increasing the cobalt content. Although the maximum magnetic entropy changes of the compounds decrease rapidly when T_C rises from 275 to 298 K, and it decreases mildly when T_C continues to rise. Two composite refrigerants based on the compounds are proposed. Their entropy changes remains approximately constant over the temperature range from 266 to 292 K and 289 to 309 K.     

Characterization of Er-doped fluoride glass ceramics waveguides containing LaF3 nanocrystals

Highly Er³⁺-doped fluoride glass ceramics planar waveguides containing LaF₃ nanocrystals have been fabricated by physical vapor deposition (PVD). The solubility of Er³⁺ in the segregated nanocrystals can reach 30 mol% which is much larger than the value found in LaF₃-oxide glass ceramics. A quantitative analysis of the photoluminescence of the 1.54 μm emission band of Er³⁺ ions has demonstrated that erbium ions are partitioned in both crystals and vitreous phase. The short lifetime (2.2 ms) measured for erbium incorporated in LaF₃ crystal lattice is a consequence of concentration quenching while the lifetime is close to 10 ms in the glassy phase. The emission bandwidth has been found to be greater than that of the precursor glass (71 nm at the half-height width). The high Er³⁺ concentration and spectral width could make this nanostructured fluoride material suitable for planar amplifier in the C telecommunication band.     

基于模糊DEA的ERP系统选型方法

提出了一种基于模糊数据包络分析的企业资源计划系统选型方法.以系统的实施复杂性、预计实施成本、功能匹配度和系统供应商的企业形象等作为主要评价指标,运用模糊集相关理论争方法对系统选型过程中的不确定性进行刻画和描述,对候选系统的相对有效性进行客观评价,解决了系统选型过程中的不确定性和模糊性问题.并通过实证研究说明了该方法的应用.     

Selection,Expression and Purification of Human Abzyme Containing Selenium with Type Ⅰ Thyroxine Deiodinase Activity

Single-chain fragment variable(ScFv) antibodies with the substrate binding sites were obtained by repetitive selections from a semi-synthetic phage display antibody library against two haptens——thyroxine(T4) and O-methyl-T4(O-CH3-T4).The positive phage clones were determined by ELISA and then cloned into vector pET30a(+).The recombined plasmids were identified by DNA sequence analysis and transformed into E.coli BL21(DE3).The expressed proteins were isolated,purified,identified by Western blot analysis,and ...