Effect of dual-scale microstructure on the toughness of laminar zirconia composites

Numerical study by the finite element method (FEM) is performed to investigate the effect of dual-scale microstructure on the toughness of laminar zirconia composite. The computation is based on the micromechanics constitutive model of polycrystal transformation plasticity developed by Sun et al. [10] where both transformation induced shear and softening effects during autocatalytic transformation are taken into account. The numerical simulation presented in this paper successfully reproduced the experimentally observed two effects of the dual-scale microstructure on the toughness of laminar zirconia composite, i.e., the truncation of the elongated transformation frontal zone that forms in single phase Ce-ZrO₂ and the propagation of the transformation zone along the layers normal to the crack plane. Quantitative analysis on the role of microstructure in transformation toughening of laminar zirconia composite is first carried out in the present work which will provide a starting point for the microstructural design of this novel advanced composite in the future.Presented at the Far East Fracture Group (FEFG) International Symposium on Fracture and Strength of Solids. 4–7 July 1994 in Xi'an, China.     

多灰度级显示器上的曲线绘制

光栅扫描显示器的屏幕是由位置固定的，离散的象素点所组成的，因而在其上生成的曲线只能是实际曲线的某种近似表示，并不是很美观的，例如有曲线的阶梯效应及曲线亮度不均度等问题，该文说明利用多灰度光栅显露器可以在一定程度上解决这些问题，并且用给出的主些算法绘制曲线时，可以较好地解决上述问题，这些算法在动画制作中也可有典型的应用。     

屏蔽暂堵反排解堵效率的实验分析

在一定实验条件下，屏蔽暂堵的反排解堵效率随压差、温度的增大而增大，反排解堵在很短的时间内就可完成。一般的反排解堵率都在60％以上，但反徘不能完全解堵。     

钻速模式动态辨识方法研究

目的：钻进过程是一个复杂的工艺过程，影响钻速的因素错综复杂。为钻井参数优化和实时控制，提出钻速动态模型。方法：对影响钻速的因素进行分析，用系统辨识方法建立钻速模式。结果：利用该方法建立了华北油田岔河集地区的钻速模型，取得满意结果。结论：此动态钻速模式能更准确、科学地描述钻进过程，并在钻井参数最优化、钻井过程的闭环控制等方面具有广阔的应用前景。     

冶金炉渣氮化物容量研究的进展

本文总结了近年冶金炉渣氮酸盐容量的研究方法，氮在炉渣中存在形态与炉渣氧分压的关系，炉渣氮化物容量与温度及炉渣成分的关系，并给出设计钢液脱氮渣系的基本原则。     

单轴-平面W型复合锶铁氧体的制备及其吸波特性研究

用草酸盐共沉淀和微量掺杂法研制六角晶系W型Ni,Zn,Co,Al多元复合锶铁氧体，通过调节Ni2W同Co2W的摩尔比例，可使该种铁氧体易磁化方向从C单轴型向垂于C轴的平面型转化，控制置换锶铁氧体中部分Fe3 的微量掺杂Al3 ，可以调整4πMs值，提高磁晶各向异性场，测试分析了5种不同含Co量的W型复合锶铁氧体粉料涂层的吸波特性，发现其自然共振吸收峰随Co含量增加向低频方向偏移，最高吸收峰可达32．8dB，是适用于电子隐形技术的高品位的微波吸收剂。     

Interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd0.96Zn0.04 Te (211)B substrates by molecular beam epitaxy

Double-crystal x-ray rocking curve (DCRC) and secondary-ion mass-spectroscopy (SIMS) measurements have been performed to investigate the effect of rapid thermal annealing on the interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd_0.96Zn_0.04Te (211)B substrates by molecular beam epitaxy. The sharp satellite peaks of the DCRC measurements on a 100-period HgTe/CdTe (100Å/100Å) superlattice show a periodic arrangement of the superlattice with high-quality interfaces. The negative direction of the entropy change obtained from the diffusion coefficients as a function of the reciprocal of the temperature after RTA indicates that the Hg diffusion for the annealed HgTe/CdTe superlattice is caused by an interstitial mechanism. The Cd and the Hg concentration profiles near the annealed HgTe/CdTe superlattice interfaces, as measured by SIMS, show a nonlinear behavior for Hg, originating from the interstitial diffusion mechanism of the Hg composition. These results indicate that a nonlinear interdiffusion behavior is dominant for HgTe/CdTe superlattices annealed at 190°C and that the rectangular shape of HgTe/CdTe superlattices may change to a parabolic shape because of the intermixing of Hg and Cd due to the thermal treatment.     

PAA-PSF交联复合膜的制备及对低浓度有机醇水溶液反渗透分离性能研究

进行了ＰＡＡ（ＰｏｌｙａｃｒｙｌｉｃＡｃｉｄ）－ＰＳＦ（Ｐｏｌｙｓｕｌｆｏｎｅ）交联复合膜的制备，研究了交联剂、添加剂对膜性能的影响，并通过扫描电镜观察了膜的断面结构．研究了ＰＡＡ－ＰＳＦ交联复合膜对低浓度有机醇类水溶液反渗透分离性能．发现对于１０００×１０－６乙醇水溶液截留率达到６６．２％，透过流束可达０．９×１０－６（ｍ３·ｍ－２·ｓ－１）．随醇的分子量的增加，截留率不断上升，对戊醇的截留率达９４．３％，而透过流束则保持相对稳定．对不同结构醇类的分离性能研究表明，截留率存在有：ｔｅｒｔ－＞ｓｅｃ－＞ｉｓｏ－＞ｎ－的规律．