一种基于多模板的超宽带信道估计算法

该文针对码片率抽头间隔的脉冲超宽带(IR-UWB)系统离散信道,提出一种基于帧(frame)级采样速率的多模板信道估计算法。在该算法中引入了若干个复合信道参数,每个复合信道参数都是几个独立信道参数的线性组合。利用极大似然准则和从多个模板中获得的帧级采样数据,可以先获得所有复合信道参数的极大似然估计值。然后联合由不同模板得到的复合信道参数估计值,得到每个独立的信道参数的极大似然估计。通过仿真,验证了该方法的可行性。     

电力系统短期负荷预测中非线性模型的研究与应用

介绍了时间序列分析中的一类非线性模型-SETAR模型的特点及其建 模，将这一模型应用于电力系统的短期日负荷预报。这种模型可以描述一些非 线性的时间序列，在负荷序列波动较大时仍能进行很好的预测，实例计算结果 表明预测精度满足要求，证实了将这一模型应用于电力系统短期负荷预测是可 行的。     

高效、节能、低污染的新型连续电弧炉

世界上第1台高效节能型连续电弧炉（环形竖炉）已在希腊投入运行,由于连续加料及炉料被炉子排出的废热气连续加热,所以其运行成本只有普通电弧炉的42%,另外的优点是：排出的烟尘非常少、低噪音、低电压闪变以及低的电能消耗。     

谈饭店行业冷凝水的回收

介绍了回收冷凝水的技术基础及在饭店行业如何具体应用等方面的基本知识。     

我国发展燃气轮机的问题及途径

论述了大功率燃气轮机在我国的应用条件及开发燃机所存在的问题,以及在设计及制造大功率,高性能燃气轮机方面需突破的技术难题和可行的解决方案,涉及了开发大流量高压比压气机,大焓降涡轮,降低有害排放量,解决高温叶片的材料,冷却,保护涂层及单晶叶片铸造等主要问题,并确认了一些关键的制造技术。     

Efficient visible light driven photocatalytic removal of NO with aerosol flow synthesized B, N-codoped TiO2 hollow spheres

In this study, we demonstrate that aerosol assisted flow synthesized B, N-codoped TiO(2) photocatalyst possesses superior photocatalytic activity to pure and single element doped counterparts on the degradation of NO in a flow system under both simulated solar light and visible light irradiation. Characterization results revealed that B, N-codoped TiO(2) photocatalyst was composed of hollow microspheres. Boron and nitrogen were in the form of Ti-O-B and N-Ti-O structures, respectively. The introduction of B and N into the TiO(2) lattice could effectively tune the band gap of TiO(2) and extend its optical response to the visible-light region. The synergistic effect of B and N codoping on visible light driven photocatalytic activity enhancement of TiO(2) was discussed on the basis of experimental results.     

Synthesis and characterization of Fe-Co binary ferrospinel nanospheres via one-step nonaqueous solution pathway

Fe-Co binary ferrospinel (CoFe₂O₄) nanospheres were synthesized by a facile nonaqueous solution route. X-ray diffraction (XRD) and electron diffraction (ED) showed that the obtained nanospheres had the cubic spinel structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the samples consisted of abundant uniform CoFe₂O₄ nanospheres with the particle size in the range of 35-40 nm. The magnetic properties of the sample were measured by using a vibrating sample magnetometer (VSM) at room temperature, which showed that the nanospheres exhibited a typical ferromagnetic behavior.     

Determination of antibacterial properties and cytocompatibility of silver-loaded coral hydroxyapatite

In this study, silver-loaded coral hydroxyapatites (SLCHAs) were used as scaffolds for bone tissue engineering. The SLCHAs were prepared by surface adsorption process and ion-exchange reaction between Ca²⁺ of coral hydroxyapatite (CHA) and Ag⁺ of silver nitrate with different concentrations at room temperature. The properties of the composite SLCHAs were investigated by inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscropy (SEM) equipped with backscattered electron detector (BSE), and energy-dispersive X-ray spectrometer (EDS). The SEM images showed that the morphology of the SLCHAs depended on the content of Ag⁺, and the silver ions were uniformly distributed on the surface of SLCHAs. The ICP-AES results demonstrated that the silver content of the SLCHAs decreased along with the decrease of the concentration of silver nitrate. The SLCHAs were found effective against Escherichia coli and Staphylococcus aureus by antibacterial test. Mouse embryonic pre-osteoblast cells (MC3T3-E1) were used to test the cytocompatibility of SLCHAs, CHA, and pure coral. Cell morphology and cell proliferation were studied with SEM, laser scanning confocal microscope (LSCM), and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay after 1, 3, and 5 days of culture. The results indicated the cell morphology and proliferation on the scaffolds of Ag⁺ (13.6 μg/ml)/CHA and Ag⁺ (1.7 μg/ml)/CHA were better than that on Ag⁺ (170 μg/ml)/CHA. In addition, adhesion of MC3T3-E1 on the scaffolds showed that the confluent cells showed fusiform shape and arranged tightly on the scaffolds. All the results showed that the antibacterial SLCHAs would have potential clinical application as the scaffolds for bone tissue engineering.     

含氟高分子生物材料的表面改性研究进展

含氟高分子材料因具有优异的稳定性和物理机械性能而成为目前研究和应用广泛的医用生物材料,但是,生物相容性的不足影响和限制了其作为体内长期植入材料的应用。因此,提高含氟高分子材料的生物相容性,尤其是通过表面改性的方法提高其生物相容性是一项有意义的研究课题。分别从改性手段和改性物质两方面综述了近年来国内外含氟高分子生物材料表面改性的研究发展。     

液氢温区下单温区双管道绝热支撑的热-结构耦合研究分析

以液氢温区下的单温区低温双管道为研究对象,对其进行了热流分析,建立了数学模型及几何模型,采用有限元方法进行了热-结构耦合分析求解,分析了不同壁厚下漏热、应力及形变的变化规律,和不同隔热孔径下的漏热、应力及形变的变化规律.研究结果表明:壁厚减小,漏热值减少,绝热支撑总体应力增加,支撑形变增大;相同壁厚下,隔热孔孔径增大,...