用动态拉伸法研究复合材料的力学行为

复合材料是由两种或两种以上物理和化学性质不同的物质组合而成的一种多相固体材料。用高强度、高模量的碳化硅纤维增强镁铝合金基复合材料既保留了镁铝合金的轻质、导热、导电性 ,又充分发挥了增强碳化硅纤维的高强度、高模量 ,获得高比强度、高比模量、导热、导电、热膨胀系数小的金属基复合材料。有关金属基复合材料强化机制的研究 ,目前已作了很多工作[1～ 3 ] 。但现有的研究多限于静态的观察、分析、研究 ,因此研究成果也受到静态特性测试结果的限制。本文应用扫描电子显微镜动态拉伸台对镁铝合金基复合材料进行了动态拉伸试验 ,跟踪…     

钛乳浊釉的扫描电镜研究

乳浊釉即在透明釉中加入乳浊剂 ,使釉中产生细小结晶体、气泡等。透明釉层中存在着密度与釉玻璃不同的微小晶粒 ,分相液滴或微小气泡时 ,入射到透明釉层中的光线遇到与波长相当或更大微粒时 ,光线被粒子表面漫反射 ,使入射光的方向改变 ,透明釉的透明度降低 ,釉层成乳浊状 ,即为乳浊釉。随着市场竞争日趋激烈 ,建筑卫生陶瓷企业越来越重视开发和利用烧后呈色的地方性原料以及工业废渣 ,从而使乳浊釉得到了更为广泛的应用[1] 。目前 ,国内陶瓷企业生产中实际普遍使用的乳浊剂是ＳｎＯ2 、ＺｒＯ2 、ＺｒＳｉＯ4。从经济和乳浊效果来看 ,锡釉…     

Observation of latch-up time evolution in CMOS IC's by means of SEM stroboscopic voltage contrast techniques

SEM stroboscopic voltage contrast techniques allow one to observe with high voltage resolution the temporal and spatial evolution of latch-up phenomena from the firing event to the final condition. In particular, the authors show by means of an example that in a CMOS IC the firing point may be different from the latch-up site in steady state. Only dynamic observations, therefore, allow a complete understanding of latch-up phenomena and an effective correction of IC layout.     

金刚石表面形态及表面金属镀层SEM研究

采用ＳＥＭ方法研究了金刚石表面花纹和缺陷，及金属镀层对金刚石性能的影响，结果表明，金刚石表面花纹对金刚石性能影响不大，金刚石表面缺陷降低金刚石性能，而金刚石表面金属镀层则提高金刚石性能，其中以超声波电镀，真空热蒸镀及化学镀三元合金效果最佳。     

Detection and evaluation of current filaments in MIS sandwich systems by applying mirror electron microscopy (MEM) and scanning electron microscopy (SEM)

Conducting channels form at weak points of an insulating layer by applying a voltage to MIS sandwich systems produced by vacuum evaporation. Local variations of the surface potential caused by the current filaments can be detected by applying MEM and SEM. An evaluation of the filament current is possible by a quantitative contrast interpretation of the corresponding image structures observed in the MEM     

煤储层中微孔隙和微裂隙的扫描电镜研究

煤是由植物遗体转变成的一种极不均一的有机岩石,植物细胞结构不同程度地得以保存。植物原始细胞结构的差异及其保存的完整程度的不同,造成煤储层中孔隙类型、孔隙大小和结构的差异。煤在变质过程中也会改变原有孔隙,并产生新孔隙。煤储层内部的不均一性不仅表现为各种孔隙的发育,还表现为微裂隙的普遍发育,因此,煤是一种多孔隙的物质。煤储层在成煤作用过程伴随有一定量的煤层气形成。煤层气主要储存在煤储层的微孔隙和微裂隙中,其扩散和运移也是在微孔隙和微裂隙中进行的。煤储层中的微孔隙和微裂隙既是煤层气储存的场所,也是煤层气产出的…     

粉煤灰中稀土元素的扫描电镜/能谱特征研究

本文用扫描电镜/能谱仪对贵阳电厂粉煤灰PM10颗粒物中的稀土元素进行了研究,发现贵阳电厂粉煤灰PM10颗粒物中稀土元素以镧系稀土La(镧)、Ce(铈)、Nd(钕)、Dy(镝)、Er(铒)、Yb(镱)为主,伴有Y(钇)和锕系稀土Th(钍),其外形特征为草霉状单颗粒物,粒径大小1~2μm,其化学形态主要为两种或两种以上混合型稀土的独居石(磷铈镧矿)或磷钇矿,以及其类质同象矿物。     

活性炭脱硫剂的SEM研究

活性炭材料是由石墨微晶和无定形炭构成的一种黑色多孔固体，孔隙结构发达，具有巨大的比表面积，对气体、溶液中的无机或有机物质及胶体颗粒等都有很强的吸附能力。以活性炭为脱硫剂吸附烟气中的SO2具有良好的应用前景。     

Fabrication of sub-wavelength antireflective structures in solar cells by utilizing modified illumination and defocus techniques in optical lithography

We demonstrate a simple method, which is combining modified illumination and defocus techniques to fabricate sub-wavelength antireflective structures for solar cells. The optimum pyramid resist and silicon profiles can be obtained after exposure, development and common dry etching processes. The reflection and transmission properties are analyzed by the rigorous coupled-wave analysis in two-dimensional microstructure and find the reflectance is dramatically increased as consideration of all diffraction orders. Therefore, patterning the sub-wavelength texturing structures for eliminating the diffraction order light is important. Patterning sub-wavelength structures should use the short wavelength combining defocus exposure or using a suitable modified illumination exposure system. The optimized pyramid structures are simulated in dosage-focus matrix with different types of light source. Results show the quadrupole modified illumination system with large process latitude is suitable for patterning sub-wavelength pyramid structures.     

数字正交检波技术在主动探测中的应用研究

提出基于光学系统的“猫眼”效应,应用单频调制的连续激光,对扫描式红外热成像目标进行有效探测的新方法。分析了光学系统的后向反射特性,针对回波信号特征,提出利用回波信号的相位信息,采用直接采样的数字正交检波技术实现对低信噪比回波信号的可靠检测,并在外场试验中应用该方案对实际目标回波信号获得了满意的检测结果。