Hierarchically porous N-doped carbon nanofibers derived from ZIF-8/PAN composites for benzene adsorption

Coupling with electrospinning technique, metal–organic-frameworks (MOFs)-derived porous carbon fibers exhibit a great potential application in the adsorption of volatile organic compounds (VOCs) because of their huge surface area, high porosity, as well as sufficient heteroatom-doped active sites. In this work, the hierarchically porous N-doped carbon nanofibers are obtained after the pyrolysis of zeolite imidazole framework-8 and polyacrylonitrile (ZIF-8/PAN) composite fibers synthesized by electrospinning method. The N-doped carbon nanofibers fabricated in N₂ atmosphere (N-CF-N₂) present an enhanced adsorption capacity of 694 mg/g for benzene because of the synergistic effect of the hierarchically porous structure and the abundant N-species-containing active sites. It is also interesting that the N-doped hierarchical carbon nanofibers fabricated in Ar atmosphere (N-CF-Ar) exhibit a low benzene adsorption as compared with the N-CF-N₂, which can be attributed to the porous structure damage caused by the bombardment of heavy Ar atoms on the pore shells during the pyrolysis. These results not only show a promising application of the as-fabricated N-CF-N₂ in adsorption of VOCs for air purification due to its merit of cost-efficient, large-scale production, and excellent adsorption capacity, but also expand the potential of electrospinning technology and composite fibers in volatile organic gas adsorption.     

变质Mn8Crl耐磨钢弥散组织的形成机制

研究了变质Ｍｎ８Ｃｒｌ耐磨钢弥散处理过程中显微组织、物相硬度及成分的变化。结果表明，通过热处理获得理想弥散组织的条件：首先是奥氏体锰钢中含有适量的强碳化物形成元素，其次是使奥氏体尽可能充分地发生珠光体转变，三是适当控制高温阶段等温温度和时间。     

Al5TiB对Mg-8Zn-4Al-0.3Mn镁合金阻尼性能的影响

研究了变质剂Al5TiB对Mg-8Zn-4Al-O．3Mn镁合金阻尼性能的影响。结果表明：Al5TiB的加入显著细化了Mg-8Zn-4Al-O．3Mn镁合金晶粒，增大了界面面积，提高了合金的界面阻尼。但是，Al5TiB的加入又促进了Al、Zn原子向基体中的扩散，降低了合金的位错阻尼。加入变质剂Al5TiB后Mg-8Zn-4Al-O．3Mn镁合金的阻尼机制主要是界面阻尼和位错阻尼。二者迭加的结果决定了ZA84镁合金的宏观阻尼行为。     

硬质合金与钢的热等静压扩散连接

研究了硬质合金ＹＧ１５Ｃ与４５~＃碳钢的热等静压扩散连接工艺，探讨厂连接温度、压力、保温保压时间、中间夹层及其厚度和连接残余热应力等对接合强度的影响．结果表明：热等静压扩散连接强度强烈依赖于连接温度，受控于连接后因ＹＧ１５Ｃ与４５~＃钢热膨胀失配而产生的残余热应力。采用镍箔作中间夹层可有效地减小残余热应力对连接的影响，显著提高接合强度．     

Flow behavior and microstructure evolution of TB8 alloy during hot deformation process

Hot compression tests of metastable β titanium alloy TB8 were carled out using a Gleeble-1500 thermal simulation testing machine in the temperature range of 750-1 100 ℃, at constant strain rate from 0.01 s^-1 to l S^-1 and with height direction reduction of 60%. Flow stress behavior and microstructure evolution during hot compression of TB8 alloy were investigated. The hyperbolic-sine-type constitutive model of TB8 alloy was obtained to provide basic data for determining reasonable forming process. The results indicate that hot deformation behavior of TB8 alloy is highly sensitive to the temperature and strain rate. An analysis of the flow stress dependence on strain rate and temperature gives a stress exponent of n=3.416 19 and a deformation activation energy of Ω=227.074 4 kJ/mol. According to the deformation microstructure, no dynamic recrystallization happens below r-phase transus temperature and as a result dynamic recovery is the predominant softening mechanism. On the other hand, the main softening mechanism is characterized as dynamic recrystallization at a slow strain rate above r-phase transus temperature.     

原位生成TiC对Al-8Fe合金显微组织的影响

通过XRD，SEM，TEM等手段研究了Al-8Fe常规铸态合金原位生成不同TiC粒子含量时相组成及显微组织的变化，以及Ti同α（Al）基体及Al3Fe相之间的界面关系。结果表明：随着TiC含量的增加，Al-8Fe合金中Al3Fe相及缩松的形貌及尺寸明显发生了变化，TiC与α（Al）基体之间界面干净，而与Al3Fe之间则存在一过渡层。     

3Cr2W8V钢渗硼后热疲劳抗力的研究

３Ｃｒ２Ｗ８Ｖ钢渗硼后热疲劳抗力的研究于长山刘喜明赵宇邬占田（吉林工学院）本文收到日期：１９９７年３月１３日初稿，１９９７年６月１７日修改稿本文联系人：于长山，男，１９３８年３月生，副教授，吉林省长春市（１３００１１）吉林工学院热处理教研室吉林省科技...     

RE对Mg-8Zn-4Al-0.3Mn合金组织的影响

研究了RE对Mg-8Zn-4Al-0．3Mn铸造镁合金显微组织的影响。结果表明：Mg-8Zn-4Al-0．3Mn-χRE铸造镁合金的显微组织主要由口(Mg)基体、φ(Al2Mg5Zn2)相、r(Mg32(Al,Zn)49)相和Mg3Al4Zn2RE相组成。随RE加入量的增加，合金晶界上三元相的形态由半连续网状改变为颗粒状，三元相的分布逐渐变得弥散而均匀。晶界上针状或棒状Mg3Al4Zn2RE相的量也随着RE加入量的增加而增加。加入1．5％的RE可显著细化合金的铸态组织，晶粒大小由120～130μm减小到40-50μm。合金的显微硬度值随着RE加入量的增加而增加。     

基于Cortex-A8的智能视频传感器的设计

视频监控在安全防范系统中有着重要作用。为了提高视频监控系统的智能化水平,设计并实现一种基于Cortex-A8的智能视频传感器。首先,以s5pv210为处理核心,TVP5150为视频采集模块,电源、网口、串口等外围辅助电路为基础,搭建视频传感器的硬件平台;然后,以嵌入式Linux为系统平台,采用TVP5150进行视频解码,Cortex-A8内置MFC进行视频压缩,在Vi Be等算法的基础上实现对检测区域的区域警戒,烟雾检测等;最后,融合硬件与软件为一体,实现智能视频传感器的设计。实验表明,该设计提高了智能视频监控系统检测报警及智能识别的实时性与准确性。     

Cortex-A8和ZigBee构成的智能餐厅系统

本文提出一种基于Cortex-A8和ZigBee的智能餐厅系统设计方案,构建了无人餐厅模型,系统通过ZigBee无线网络连接自助点菜终端、PC主机端、网关端、厨房端、送餐车、清洁车等模块,最终实现了通过Web服务器、CGI接口、云计算平台等方式提供远程订餐服务。经测试,本方案可实现包括自助点菜、送餐、清洁、结算、网页微信订餐等功能。