Wet Green‐State Joining of Alumina Ceramics Without Paste

A new technique for the green‐state joining of alumina ceramics without paste has been developed. Wet alumina green body, gelcast by PIBM (a copolymer of isobutylene and maleic anhydride) gel system, is used as a parent green body. The joining process involves integrating two wet green bodies in a gelling state, followed by drying and sintering. For example, wet green bodies after aging 10 h were joined, and the joint region of the dried and sintered sample exhibited a homogeneous microstructure without defects or an interlayer. The flexural strength of the joined sample (468.5 ± 62.9 MPa) was nearly equivalent to that of a monolithic sample (470.6 ± 27.4 MPa). The joining mechanism was discussed on the basis of interaction among PIBM molecular chains. The proposed joining technique is simple and promising for producing advanced ceramics with large sizes and/or complicated shapes.     

低硫微合金钢中MnS析出及晶内铁素体形成研究

采用真空感应炉冶炼Al-Si-Mn-Ti复合脱氧的低硫微合金钢,通过热力学计算对钢液凝固过程中Mn S析出规律进行分析,运用带X射线能谱分析仪的场发射扫描电镜对夹杂物形貌、尺寸和成分以及Mn S在复合氧化物上的析出形态进行分析。结果表明:Mn S的析出主要受液相中Mn、S含量和液相温度控制。Mn-Si,Mn-Ti,Al-Mn-Ti,Al-Mn-Si复合氧化物都能作Mn S析出的核心,Mn S在硅锰氧化物表面呈镶嵌状析出,在钛锰氧化物表面呈包裹状析出,还可溶解在铝钛锰和铝硅锰氧化物的内部。诱发IGF形核的复合夹杂物尺寸为2~3μm。     

地下储气库注采管柱气密封螺纹接头优选

为解决国内地下储气库井注采管柱气密封螺纹接头选用混乱且适用性不清的问题,首先对现有标准和气密封试验数据进行统计比对分析,发现各种气密封螺纹接头的拉伸效率相同,但其压缩效率差异大且现有标准已不适用于储气库注采管柱气密封螺纹接头的选择,认为注采管柱气密封螺纹接头的选择必须考虑管柱载荷的交变;然后结合2口储气库井注采工况,基于管柱力学理论计算获得2种规格注采管柱的最大拉伸载荷和最大压缩载荷,对比已选用的气密封螺纹接头,重点研究了接头拉伸效率、压缩效率与管柱载荷之间的关系,提出了注采管柱气密封螺纹接头优选判据;进一步利用全尺寸实物复合加载试验机对2种规格注采管柱进行多周次气密封循环试验,试验结果证实了上述判据的合理性。所提出的优选判据不仅可以作为气密封螺纹接头优选的基本依据,而且还可以作为储气库井注采管柱设计的依据,并纳入了中国石油天然气行业标准。     

电力电子设备热设计的分析及应用

针对可再生能源的发展，风机变流器和并网逆变器的广泛应用，提出了电力电子设备热设计的分析及应用，通过名热设计方法使元器件、零部件、设备等在低于规定的热环境中工作，以提高可靠性。     

我国银行业营业收入结构失衡的成因及对策

对我国银行业的营业收入结构、主要特征及其成因分析显示,银行垄断是造成目前我国银行业利润持续高增长的最主要原因,也给我国经济发展带来了较大负面影响。只有深化利率市场化改革,采取鼓励和引导更多民间资本进入银行业等政策措施,才能逐步破除银行垄断,实现金融对我国经济发展的促进作用。     

Preparation and characterization of fly ashes and polyaniline core/shell microspheres

To modify the surface of fly ashes (FAs), conductive polyaniline (PANI) layer were chemically grafted on the surface of the self-assembled monolayer (SAM) coated FA particles, resulting in SAM-FAs/PANI composites. The surface functionalization of FAs with amino groups was found to play an important role in the formation of the well-defined core/shell structure. The composites possess good conductivity, average specific capacitance and good magnetic properties at room temperature. Moreover, the conductivity stability and thermal stability of SAM-FAs/PANI composites were clearly improved. The resulting composites were characterized by using wide-angle X-ray diffraction analysis, Fourier transform IR spectroscopy, UV–vis spectroscopy, thermogravimetric analysis, and scanning electron microscopy.     

新型聚羧酸系保塑剂的性能研究

针对混凝土坍落度损失较快问题,研制了一种梯形结构聚羧酸系保塑剂,对该保塑剂的性能研究结果表明,在低掺量时具有高坍落度保持能力,其混凝土工作性好,与水泥适应性良好,与减水剂复配后效果明显优于单掺.掺入保塑剂后,可明显减缓水泥早期水化放热速率,有利于提高混凝土的抗裂性.     

Excel的相对引用、绝对引用和混合引用

利用Excel电子表格处理软件的特点将会计、统计等工作人员从传统的工作模式中解放出来,利用计算机进行数据录入、统计计算,帮助他们减少繁琐的重复计算,减轻会计核算的工作量,降低成本,轻松实现电算化。     

基于数字化改造提高安全播出保障能力的实践

通过"数字化工作区"建设,本台的业务水平和技术保障能力都有了极大提高,重点介绍了"数字化工作区"建设方案和实施的成功经验,供同行参考借鉴。     

人际信息交互中低功耗网络发现应用研究

无线人际信息交互网络围绕人际信息交互的特点展开。重点关注无线通信中的网络发现中的能耗问题,利用IEEE802.15.4网络的超帧结构,提出了一种通过变换超帧参数实现的低功耗网络发现算法,分析了该算法的能耗与时间约束的关系。最后,在硬件平台上开发了电子名片应用以测试网络发现算法的有效性。