Low packing density self-assembled superstructure of octahedral Pt3Ni nanocrystals

We present a structural study of Pt(3)Ni nanoctahedron superlattice, prepared through both drop-casting and controlled solvent evaporation approaches. In this superlattice system containing ～10.6 nm side-length Pt(3)Ni nanoctahedra, we observed a body-centered cubic (bcc) packing structure in both local superlattices and statistically averaged superlattice ensembles using transmission electron microscopic tomography and grazing-incidence small-angle X-ray scattering techniques, respectively. Within the superstructure, it was directly observed that nanoctahedra are orientated along the superstructure axes through sharing their vertices. We found that this arrangement of a bcc superstructure with nanoctahedra connecting through their vertices is dependent on neither the processing pathway nor the substrate under our experimental conditions. With such a very low packing density and ultrahigh surface area, this type of self-organized superstructure possesses unique features for future applications.     

电流变减振器的参数估计与减振性能研究

本文对研制的多层极板式电流变减振器进行了正弦和随机激励实验，发现这种减振器在低频时减振效果非常明显，在高电场时减振器表现出明显的非线性特性，减振器还具有移频特性，即减振器的刚度在电场作用下发生变化。为了比较，对一种滑动极板减振器进行了对比实验。最后用递归最小平方法估计了减振器的粘性阻尼和库仑阻尼，估计时考虑了刚度的变化，估计的结果与实验结果一致。     

Al18B4O33W/Mg复合材料制备方法及其对材料性能及界面的影响

综述了硼酸铝晶须增强镁基复合材料的研究概况,着重介绍了该复合材料的制备方法、性能、界面行为以及制备工艺对其影响,并对硼酸铝晶须增强镁基复合材料当前研究当中存在的一些问题以及某些需要深入研究的方向进行了探讨.     

MgO/La2O3CO3复合材料对磷酸盐的吸附特征

采用水热法制备了MgO/La2 O2 CO3复合材料(ML).采用X射线衍射仪和扫描电子显微镜对其结构及表面形貌进行了表征,利用Zeta电位仪测定了其零点电位点,并探究了接触时间、初始磷酸盐浓度和初始pH对磷酸盐吸附效果的影响.结果 表明,ML呈现板块状堆叠而成的层状结构,零点电位点为4.52.准二级动力学模型和Fre...     

光面爆破合理炮孔密集系数的研究

通过分析光面爆破机理，从最优成缝的原则和最优破碎块度两方面分析了光爆中最优炮孔密集系数的取值。计算结果表明，岩石的最优炮孔密集系数为０．９５～１．２０，合理范围在０．７～１．３之间，这与模型试验和工业试验的结果相吻合。文中有关公式和数据可供施工中参考。     

Torsion sensor based on two cascaded long period fiber gratings fabricated by CO2 laser pulse irradiation and HF etching technique respectively

A novel torsion sensor is proposed, which is composed of one long period fibre grating and one asymmetrically corrugated long period fibre grating based on the high-frequency CO₂ laser pulses technology and burning fibre coating and etching cladding technology, respectively. By combing the advantages of the two aforementioned elements, a sensitivity of 331.7 and 310.3 pm/(rad/m) towards clockwise and anticlockwise direction, respectively, is reached in the experiments.     

气测录井资料在泌阳凹陷稠油区钻井中的导向及评价作用

针对泌阳凹陷稠油区油层埋藏浅、成岩性差、地层相变严重、非均质性强的特点,在分析该区稠油形成原因和气测异常特征的基础上,认为在该稠油区钻大斜度井及水平井时,应用气测录井进行地质导向具有反应速度快、抗污染能力强、可有效恢复岩性剖面的优势。根据该稠油区气测录井的全烃和甲烷特征,结合钻时及相关录井资料,以XD1井大斜度定向井为例,阐述了适用于该稠油区的气测录井的地质导向和油层解释方法。实际应用情况表明,气测录井结合钻时进行该稠油区钻井过程中的地质导向,比使用LWD等先进装备具有开发成本低、技术上简便可靠的特点,且效果较好。     

R410A冷凝器性能的仿真

以往通过经验公式法对空调器性能进行仿真,只在局部范围内精度较高,本文通过分段多项式法对替代工质R410A进行了物性计算.仿真结果精度较高,误差小于2%,且适用范围广.     

聚苯并咪唑在高温质子交换膜燃料电池中的应用研究进展

简要介绍了一类高性能聚合物—聚苯并咪唑的制备方法及其在高温质子交换膜燃料电池中的应用研究进展;阐述了磷酸掺杂聚苯并咪唑膜的质子传导机理,探讨了磷酸掺杂率对聚苯并咪唑膜的力学强度和质子导电率等性能的影响规律;并对今后磷酸掺杂聚苯并咪唑质子交换膜研究领域需要解决的关键问题进行了讨论.