轮胎原料胶体的热解特性研究

提出热解可以作为废旧轮胎资源化处理的重要途径,选择轮胎原料胶体为对象,对其进行热重实验和固定床热解实验.结果表明:样品的失重温度区间在200~500℃之间,总失重率约为66%.热解实验发现,热解气主要由甲烷、氢气和二氧化碳组成;热解油的主要组成为单环芳香烃苯系物和含量高达19.77%的D-柠檬烯等较高价值的化合物.     

长白山重点国有林区森林资源动态分析--以临江林业局为例

以临江林业局为例,分析了1977—2008年长白山重点国有林区森林资源动态变化情况,并提出今后森林资源经营管理的建议.结果表明:临江林业局林业用地面积和有林地面积均呈先下降后上升趋势,林地利用效率逐渐提高.1977—1997年,天然林面积逐年大幅减少,减少率约为37%,而后逐年上升;阔叶林蓄积所占比例大幅减少,针叶林蓄积比例大幅增加,针阔混交林蓄积占比趋向合理;1987年,中龄林面积和蓄积比例均很大;2008年林分各龄组面积和蓄积占比趋向合理.     

大规模MIMO系统中的双向搜索天线选择算法

大规模MIMO(Massive MIMO)拥有众多天线,如果按照传统的方式配备等量的射频链路,势必会大幅度增加硬件成本及系统复杂度.天线选择技术能够在不损害多天线系统优势的前提下,使射频链路成本明显下降.天线选择的主要方法其思想是在全部天线中选出部分天线传输数据,从而使射频链路成本不再成为限制因素,在实际的无线信道中,信道状态变化多样,为了达到所需性能指标,通信系统需要选择不同数目的天线进行数据传输,而现有的天线选择算法往往只适用于固定天线数的场景.本文针对多变的信道状态,基于递增选择算法与递减选择算法提出了双向搜索天线选择算法,能够灵活应对不同的天线数需求,并且保持了较低的计算复杂度.     

Burn-resistant behavior and mechanism of Ti14 alloy

The direct-current simulation burning method was used to investigate the burn-resistant behavior of Ti14 titanium alloy. The results show that Ti14 alloy exhibits a better burn resistance than TC4 alloy (Ti–6Al–4V). Cu is observed to preferentially migrate to the surface of Ti14 alloy during the burning reaction, and the burned product contains Cu, Cu₂O, and TiO₂. An oxide layer mainly comprising loose TiO₂ is observed beneath the burned product. Meanwhile, Ti₂Cu precipitates at grain boundaries near the interface of the oxide layer, preventing the contact between O₂ and Ti and forming a rapid diffusion layer near the matrix interface. Consequently, a multiple-layer structure with a Cu-enriched layer (burned product)/Cu-lean layer (oxide layer)/Cu-enriched layer (rapid diffusion layer) configuration is formed in the burn heat-affected zone of Ti14 alloy; this multiple-layer structure is beneficial for preventing O₂ diffusion. Furthermore, although Al can migrate to form Al₂O₃ on the surface of TC4 alloy, the burn-resistant ability of TC4 is unimproved because the Al₂O₃ is discontinuous and not present in sufficient quantity.     

基于GCRN的矿岩可爆性分级模型及其应用

为了准确反映岩体可爆性等级,构建了由弹性波阻抗、坚固性系数、平均裂隙距和标准爆破漏斗炸药单耗4个因素组成的评价体系,采用改进的灰色关联分析法对传统的岩体可爆性等级划分标准进行优化。利用灰色关联相对贴近度(GCRN)来反映各可爆性等级之间的差别,确定各可爆性等级对应的灰色关联相对贴近度区间,以此划分新的岩体可爆性等级。采用基于GCRN的矿岩可爆性分级模型对武钢资源集团公司程潮矿业有限公司东、西区矿体的可爆性级别进行评价,评价结果与实际情况基本一致,表明利用灰色关联相对贴近度来划分矿岩可爆性等级的方法是可行的。     

Corrosion behavior of low alloy steels in a wet–dry acid humid environment

The corrosion behavior of corrosion resistant steel (CRS) in a simulated wet–dry acid humid environment was investigated and compared with carbon steel (CS) using corrosion loss, polarization curves, X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe micro-analysis (EPMA), N₂ adsorption, and X-ray photoelectron spectroscopy (XPS). The results show that the corrosion kinetics of both steels were closely related to the composition and compactness of the rust, and the electrochemical properties of rusted steel. Small amounts of Cu, Cr, and Ni in CRS increased the amount of amorphous phases and decreased the content of γ-FeOOH in the rust, resulting in higher compactness and electrochemical stability of the CRS rust. The elements Cu, Cr, and Ni were uniformly distributed in the CRS rust and formed CuFeO₂, Cu₂O, CrOOH, NiFe₂O₄, and Ni₂O₃, which enhanced the corrosion resistance of CRS in the wet–dry acid humid environment.     

Investigations of a nanostructured FeMnSi shape memory alloy produced via severe plastic deformation

Low-cost iron-based shape memory alloys (SMAs) show great potential for engineering applications. The developments of new processing techniques have recently enabled the production of nanocrystalline materials with improved properties. These developments have opened avenues for newer applications for SMAs. The influence of severe plastic deformation induced by the high-speed high-pressure torsion (HSHPT) process on the microstructural evolution of an Fe–Mn–Si–Cr alloy was investigated. Transmission electron microscopic analysis of the alloy revealed the existence of nanoscale grains with an abundance of stacking faults. The high density of dislocations characteristic of severe plastic deformation was not observed in this alloy. X-ray diffraction studies revealed the presence of ε-martensite with an HCP crystal structure and γ-phase with an FCC structure.     

《电子政务与信息技术》网络课程的设计与创新

《电子政务与信息技术》网络课程开发的目的是为国家公务员提供全面、优质、便捷的在线信息化培训．目前,该课程已基本完成,正处于试播阶段．本文主要总结《电子政务与信息技术》网络课程的设计和技术创新．     

马铃薯淀粉渣制取草酸的研究

研究了以马铃薯淀粉渣为原料,采用水解一氧化的方法制取草酸的最佳反应条件：当用硫酸浸泡４ｈ,硝酸／淀粉渣质量比为２．３７—２．４５,氧化反应温度６５－７５℃,反应时间５—６ｈ,草酸二水合物收率＞６５％。该法工艺简单,成本低廉,有较高的经济和社会效益。     

乌索酸的一般药理学实验研究

对乌索酸进行一般药理学研究．按药理学研究方法观察乌索酸对动物精神活动、神经系统、心血管系统、呼吸系统的影响．结果表明ig UA22,11,5．5mg/kg对猫的心率、血压、心电图及呼吸均无明显改变;ig UA240,120,60mg/kg对小鼠的精神、神经系统亦无影响．提示：乌索酸对动物无明显毒、副作用。