硫酸/盐酸比例和Al~(3+)含量对铝箔隧道孔生长的影响

研究了硫酸/盐酸比例、温度和Al3+含量对高纯铝箔隧道孔生长的影响,发现随着硫酸浓度增加,温度对隧道孔极限长度和孔径的影响减小,在本文条件下隧道孔生长的临界温度最低可降低到35℃。在电解液中一定含量的Al3+可以避免铝箔表面形成大孔,从而改善隧道孔分布均匀性。     

谈影响钻孔灌注桩承载力的因素

根据目前我国钻孔灌注桩的特点，从施工工艺方面，对控制沉渣、孔壁泥层过厚的问题进行了探讨，提出了合理、有效的措施，以确保桩基础承载力的正常发挥。     

Preparation and gas-sensing characteristics of nanocrystalline spinel zinc ferrite thin films

Zinc ferrite is a promising sensor material. In this paper, thin films of nanocrystalline zinc ferrite were deposited on alumina substrates by nebulization of a 0.01-M solution of a mixture of ZnCl/sub 2/ and FeCl/sub 3/ in ethanol (Zn:Fe=1:2) followed by pyrolysis and annealing in flowing air. The resulting films were characterized by X-ray diffraction and scanning electron microscopy, and the gas-sensing properties of as-deposited films were also investigated.     

NMR structure and mutagenesis of the FADD (Mort1) death-effector domain

When activated, membrane-bound receptors for Fas and tumour-necrosis factor initiate programmed cell death by recruiting the death domain of the adaptor protein FADD to the membrane. FADD then activates caspase 8 (also known as FLICE or MACH) through an interaction between the death-effector domains of FADD and caspase 8. This ultimately leads to the apoptotic response. Death-effector domains and homologous protein modules known as caspase-recruitment domains have been found in several proteins and are important regulators of caspase (FLICE) activity and of apoptosis. Here we describe the solution structure of a soluble, biologically active mutant of the FADD death-effector domain. The structure consists of six antiparallel, amphipathic alpha-helices and resembles the overall fold of the death domains of Fas and p75. Despite this structural similarity, mutations that inhibit protein-protein interactions involving the Fas death domain have no effect when introduced into the FADD death-effector domain. Instead, a hydrophobic region of the FADD death-effector domain that is not present in the death domains is vital for binding to FLICE and for apoptotic activity.     

Crystallographic shear planes in nanocrystalline SnO2 thin films by high-resolution transmission electron microscopy

Atomic structures of crystallographic shear planes (CSPs) in nanocrystalline thin films of semiconductor SnO₂ were investigated by high-resolution electron microscopy. The films were prepared by electron beam evaporation in high vacuum (10^–6 torr) and followed by annealing in synthetic air at 700 °C for 1–2 H. CSPs with the displacement vector of [1/2 0 1/2] were observed in the planes parallel to (¯101), (110) and (¯3¯21). Most of the CPSs were found to terminate or interact with each other within SnO₂ crystallites. Partial dislocations exist at terminal places of CSPs or along intersecting lines of CSPs. CSP steps were also observed. Structural models of these defects have been proposed. Based on analysis of experimental data, it has been suggested that the Sn/O ratio at CSPs which are not parallel to their displacement vector, at cores of partial dislocations and at CSP steps, is higher than that of the perfect structure, that is, these defects are able to provide extra free electrons with the films.     

Preparation of Pb(Zr0.52Ti484848)O3 thin films on silicon-on-insulator substrates by excimer laser deposition combined with rapid thermal annealing

In this paper we report the fabrication of ferroelectric Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films on Si-on-Insulator (SOI) substrates with and without an electrode by pulsed excimer laser deposition combined with rapid thermal annealing. Based on the structural and interfacial characteristics analysis by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), cross-sectional transmission electron microscopy (XTEM) and automatic spreading resistance measurement (ASR), the film structure and orientation were revealed to be dependent on the annealing time and annealing temperature as well as deposition temperature. From RBS spectra and XTEM observation it is shown that the PZT thin films did not interact with the top silicon layers of SOI and that the composition of the film was similar to the target. The ASR measurements showed that the electrical properties of PZT/SOI as well as PZT/Pt/SOI were abrupt, and that the electrical properties of the SOI substrates were still good after the PZT growth.     

半导体激光器用铷D2线光电流谱稳频

本文报导了用铷原子７８００Ａ光电流谱来稳定半导体激光器的工作，在光电流谱线的中部发现了有利于稳频的凹陷，将半导体激光器频率锁定在凹陷的中央，估算的频率稳定度为１ＭＨｚ。     

建立数据库用微机进行钻井液设计

为了更好地指导现场钻井液施工,利用微机建立有关数据库和相应的设计软件,根据地质、工程的要求和井下情况进行钻井液设计,其特点是资料全面、程序运行可靠且操作简便,设计符合现场情况,施工顺利。在千12区块,用微机设计的109口井与人工设计的75口井相比,钻井速度提高,井下复杂情况减少,提高了经济效益。     

无机添加剂的浓度及pH值对纺锤形α－Fe_2O_3晶貌的影响

本文以高浓度Ｆｅ３＋盐溶液为原料，采用沸腾回流的强迫水解法研究了无机添加剂浓度及反应液初始ｐＨ值对产物纺锤形α－Ｆｅ２Ｏ３晶貌的影响。结果表明，添加剂浓度和反应液初始ｐＨ值对纺锤形α－Ｆｅ２Ｏ３的轴比具有明显的影响，并且当添加剂浓度增加到一定值时，纺锤形α－Ｆｅ２Ｏ３出现解体。