水合磷酸钴铵晶体材料的低热固相法合成及表征

以CoCl2.6H2O和(NH4)3PO4.3H2O为原料,在适量表面活性剂聚乙二醇(PEG-400)的存在下,在室温(R.T.)研磨反应混合物进行固相反应,将反应混合物在不同的温度(80℃,60℃,R.T.)保温陈化4 h,用水洗去混合物中可溶性的无机盐,在110℃下烘干2 h,得到一水合磷酸钴铵晶体材料。用XRD,IR,SEM及TG/DTA对产物进行了表征。结果表明,3种不同保温温度均得到具有正交晶系物相,空间群为Pmn21(31)的片状(NH4)3CoPO4.H2O晶体材料。     

石膏基植物纤维板的吸水性及防水措施

从石膏晶体结构、植物纤维结构及石膏基植物纤维板的显微结构与材料特性出发,探讨了石膏基植物纤维板的吸水原理,以及相应的防水措施。总结了国内外有关石膏与植物纤维耐水性研究工作的现状,阐释了石膏植物纤维板耐水方面的应用特点。     

多岩性储集层暂堵压裂缝高扩展特征试验研究

针对多岩性组合储集层的裂缝高度扩展问题,通过制备不同岩性的人工试样,并开展了室内压裂物理模拟试验,同时加入暂堵剂,分析不同岩性差异、射孔位置及排量下的水力压裂缝高扩展特征,创新了试样压后三维裂缝重构方法。结果表明：不同岩性组合试样下的主要缝高截止机制由岩石力学性质所决定,高杨氏模量岩层会阻挡缝高穿层。当层间力学性质差异较小时,裂缝发生转向扩展突破,缝高发生穿层;当层间力学性质差异较大时,裂缝扩展限制于同一岩层,缝高难以突破岩层界面。低排量下,缝高截止于应力区分界面,暂堵压裂后,裂高继续延伸突破高应力区;高排量下,裂缝沿最小主应力横向扩展,加入暂堵剂发生,裂缝转向形成新的裂缝。当射孔位置居上时,试样缝高倾向于向上扩展,暂堵压裂后形成新的起裂点;射孔位置居下,缝高扩展贯穿整个试样,暂堵压裂后形成相平行的新裂缝。研究结果为多岩性组合储集层现场压裂方案设计提供了室内试验指导。     

中间相沥青基介孔炭的表征及其用作锂离子电池负极材料的电化学性能

以中间相沥青为碳源、CaCO_3为模板,制备中间相沥青基介孔炭(MPMC)。采用XRD、SEM、TEM等手段表征所制介孔炭的结构和形貌,并将其用作锂离子电池的负极材料,测试电化学性能。结果表明,所制MPMC具有丰富的介孔结构和较大的比表面积及孔体积,随着CaCO_3质量分数的增加,MPMC的比表面积和孔体积先增加后减小,当CaCO_3的质量分数为70%时,所制MPMC的比表面积和孔体积最大;MPMC用作锂离子电池负极材料具有良好的电化学性能,能有效提高锂离子电池的可逆比容量,具有良好的循环稳定性和倍率性能。     

制冷背心用于隔绝式防护服中的传热模型研究

采用芯材为石蜡,壁材为密胺树脂,相变温度为35.66℃,相变潜热为158.7J/g的微胶囊相变材料制备制冷背心原理样衣,与隔绝式防护服配套使用,并委托中国人民解放军北京防化研究院生理评价试验中心对制冷背心进行生理评价试验。在室温36℃,相对湿度60%的条件下,测定穿着隔绝式防护服配有制冷背心前后的人体胸温、手温、腿温和肛温等参数随穿着时间的变化关系;结合人体产热,散热经验式与伍德科克人体散热理论建立模型,探讨人体穿着隔绝式防护服配有制冷背心前后人体平均体温随穿着时间的变化关系,并对如何提高人体着装舒适度和延长隔绝式防护服穿着生理时限进行综合分析。结果表明：穿着隔绝式防护服配有制冷背心前后,人体胸温、背温、手温、腿温和肛温明显下降;通过建模计算分析,穿着隔绝式防护服配有制冷背心前后的人体平均体温随穿着时间的变化关系计算值与实验测试结果吻合,变化趋势一致;在相同条件下,穿着配有制冷背心的隔绝式防护服过程中,人体体温较穿着未配有制冷背心的隔绝式防护服有所下降,上升幅度较小。     

药型罩材料对EFP水中运动特性影响研究

针对药型罩材料对爆炸成型弹丸（EFP）水中运动特性的影响问题,本文利用ANSYS/LS-DYNA有限元分析软件,基于紫铜材料EFP水中侵彻试验基础,结合相关理论研究仿真对比分析了不同密度材料（10号钢、钽及铝）、同密度材料（纯铁、10号钢、20号钢）以及高密度材料（钽、钨）所形成EFP的水中侵彻情况,找出药型罩材料性能对EFP水中速度衰减的影响.结果表明,密度对EFP水中侵彻过程具有至关重要的影响,EFP形状一定的条件下密度越高则存速能力越强,若密度相近则衰减规律趋于一致,且钽、钨等重金属药型罩在水中聚能战斗部的应用具有广阔前景.     

Skin collagen fiber-based radar absorbing materials

By using skin collagen fiber (CF) as raw material,Schiff base structure containing CF (Sa-CF) was synthesized through CF-salicylaldehyde reaction.Then a novel radar absorbing material (Fe-Sa-CF) was prepared by chelating reaction between Sa-CF and Fe 3+.The coaxial transmission and reflection method was used to analyze the complex permittivity and complex magnetic permeability of these CF-based materials,and the radar cross section (RCS) method was used to investigate their radar absorbing properties in the frequency range of 1.0-18.0 GHz.Experimental results indicated that the conductivity of CF increased from initial 1.08×10-11 to 2.86×10-6 S/cm after being transferred into Fe-Sa-CF,and its dielectric loss tangent (tanδ) in the frequency range of 1.0-17.0 GHz also increased.These facts suggest that the Fe-Sa-CF is electric-loss type radar absorbing material.In the frequency range of 3.0-18.0 GHz,Sa-CF (1.0 mm in thickness) exhibited somewhat radar absorbing property with maximum radar reflection loss (RL) of-4.73 dB.As for Fe-Sa-CF,the absorbing bandwidth was broadened,and the absorbing intensity significantly increased in the frequency range of 1.0-18.0 GHz where a maximum radar RL of-9.23 dB was observed.In addition,the radar absorbing intensity of Fe-Sa-CF can be further improved by increasing membrane thickness.When the thickness reached to 2.0 mm,the RL values of Fe-Sa-CF were-15.0-18.0 dB in the frequency range of 7.0-18.0 GHz.Consequently,a kind of novel radar absorbing material can be prepared by chemical modification of collagen fiber,which is characterized by thin thickness,low density,broad absorption bandwidth and high absorption intensity.     

粉煤灰/壳聚糖复合材料处理高浊水的研究

为解决高浊水除浊问题,使用酸改性粉煤灰与壳聚糖按照不同质量比制备成的复合材料对高浊水进行处理。通过单因素实验和正交试验得出了粉煤灰与壳聚糖复合材料投加量、搅拌时间、pH和废水初始浊度对除浊性能的影响以及各因素综合作用对除浊率的影响。单因素实验结果表明：当粉煤灰与壳聚糖质量比为6:1时,其除浊率可达到93.78%;当复合材料CWF3投加量为0.6 g时,其除浊率可达到73.52%;当搅拌时间为30 min时,其除浊率可达到90.28%;当pH=6时,其除浊率可达到84.50%;当初始浊度为300 NTU时,其除浊率可达到95.67%。正交试验结果表明,当粉煤灰与壳聚糖质量比为6:1,最佳组合条件为投加量0.7 g、搅拌时间35 min、废水初始pH=7、废水初始浊度350 NTU。酸改性粉煤灰负载壳聚糖后具有更强的亲和能力,且价格便宜,可以弥补单独使用粉煤灰或壳聚糖的不足,可用于对大规模废水进行处理。     

Synthesis of the 3D porous carbon-manganese oxide (3D-C@MnO) nanocomposite and its supercapacitor behavior study

A 3D porous carbon-manganese oxide ([email protected]) nanocomposite is successfully synthesized via a thermal plasma deposition method. The chemical bonds and compositions, phase structures, surface morphologies, etc. of as-obtained [email protected] nanocomposite were characterized by the various equipment, such as X-ray diffractometer, X-ray photoelectron spectroscopy, and electron microscopes. The electrochemical performances of the [email protected] nanocomposite electrode showed a specific capacitance of 780 F g^?1 at a current density of 2 A g^?1 and a capacitance retention rate of 99% after 5000 charge-discharge cycles at a high current density of 10 A g^?1. These excellent capacitive performances may be attributed to the encapsulation of MnO nanoparticles by porous carbon sheets in the [email protected] MnO nanocomposite structure. It is believed that the carbon-encapsulated MnO nanoparticles can be protected from a volume deformation during the charge adsorption/desorption cycle and can be electrically improved by the encapsulated carbon sheets, resulting in better overall capacitive performance. In addition, this study also demonstrates the practical applicability by assembling a supercapacitor using the as-obtained [email protected] nanocomposite to glow a light emitting diode.     

浅谈水泥稳定碎石基层的质量控制

通过对基层的设计、试验、施工等各个环节的控制，提高水泥稳定碎石基层的强度，控制其裂缝的产生，从而保证工程质量。