骨质疏松实验模型形态观察与计量分析

随着老年型社会的出现 ,作为老年性疾病之一的骨质疏松发病率和死亡率呈上升趋势 ,已成为危害老年人健康的大问题。骨质疏松症 (Ｏｓｔｅｏｐｏｒｏｓｉｓ)主要指骨量和骨细胞的减少 ,骨皮质变薄 ,骨矿化和化学成分不正常的一种代谢性疾病 ,使骨组织的正常载荷功能发生变化 ,骨折危险度增加。本文报道了大鼠骨质疏松模型的建立及其形态学的观察和图像分析及计量方法的测定 ,这在本模型的应用资料中尚不多见。材料与方法取清洁级雌性大鼠 ,无菌条件下摘除双侧卵巢 ;阴性对照组切除双侧一小块脂肪。 5日后取存活健康大鼠 2 4只 ,随机分为 3组 …     

振荡神经网络的建模与动态联想记忆

本文提出一种全程耦合映射格子式的振荡神经网络模型，该模型具有丰富的非线性动力学行为，在其联想记忆的数值模拟中，观察到同步振荡和时空混沌现象。该网络的动态特性有助于区分具有相同吸引子的不同模式。     

应用于极紫外光刻系统多层膜的研究进展

极紫外光刻是采用波长为13.5nm的极紫外光作为光源,实现半导体集成电路工艺22纳米以及更窄线宽节点的主要候选光刻技术。性能优越稳定的多层膜技术是构建整个极紫外光刻系统的重要技术之一。从高反射率,波长匹配,控制面形以及稳定性和寿命方面总结了极紫外光刻系统中多层膜的性能要求和最新的研究进展,叙述了制备高性能多层膜的方法和沉积设备,讨论了多层膜制备技术还存在的问题和发展的方向。     

溶胶凝胶法制备钼掺杂氧化锌薄膜及性质研究

利用溶胶凝胶法在Al₂O ₃衬底上制备出了c轴择优取向的钼掺杂氧化锌（MZO）透明导电薄膜,研究了钼的掺杂量(0~1 at%)对钼掺杂氧化锌薄膜光电性能的影响。研究结果表明：所制备的薄膜为六方纤锌矿型结构且表面平整、致密,通过高温真空退火,MZO薄膜的电阻率明显降低,且随着钼含量的增加,MZO薄膜的电阻率呈现出先减小后增大的趋势,当钼含量为0.4at.%时,获得最小电阻率为0.13 Ωcm。薄膜在近红外区域(800~2000 nm)的平均透过率大于85%,这可以有效地拓宽光电器件的光谱范围。     

Preparation of broadband antireflective coating by sol-gel method

A sol-gel method for the preparation of silica coating that varied in refractive index is developed. Silicon dioxide sol is obtained by hydrolysis and co-condensation reactions occurred in acid-catalyzed system. Surface morphology, refractive index, and transmission spectrum of the samples are studied. The results of transmission spectra of single-sided coatings show that the average transmittance of the samples increases about 4% compared with the uncoated one in the spectra range from 400 to 1 200 nm in the case of vertical incidence. For the double-sided coating the maximum transmittance is 99% at the wavelength of 840 nm.     

Study of aluminum coating prepared by PVD used as anti-corrosion in liquid lead-bismuth

Liquid metals-such as lead （Pb） or lead-bismuth （PbBi） are used as reactor core coolants for accelerator driven systems （ADS） proposed for high-level radioactive waste transmutation. Compatibility of steels with liquid PbBi is a key problem because steels are attacked by dissolution of the components in PbBi, so it has to form a stable coating on steel surface. There are many methods to prepare anti-corrosion coatings on steel, such as hot dipping, pack cementation, plasma spaying, and physical vapor deposition （PVD）. Compared with other methods, the PVD method is easy to control the thickness of the coating and the obtained coatings are dense which is crucial to the anti-corrosion ability of the coatings. In this letter, PVD aluminum coatings are developed on the surface of T91 steel and different heat-treatment atmosphere is used to adjust the microstructure, aluminum content, and the phase of the coatings. It is found that the coatings have good adherence ability with steel. The aluminum content and the phase of the coating can be adjusted by the heat-treatment atmosphere. Corrosion tests are performed in oxygen-saturated liquid PbBi at 550 ℃ for 1 000 h, the phase and composition of the coating do not change drastically. All the results indicate that the PVD is a useful method to prepare coatings on the surface of steel used in liquid PbBi.     

新型薄膜材料在激光能量／功率计应用中的新进展

介绍了目前新型薄膜材料在激光能量／功率计应用中的最新试验研究进展。最近从实验中发现多种新型材料的薄膜具有光热辐射感生热电电压,对这种基于各向异性塞贝克效应的感生电压的性质进行详细的研究,发现并证明此类薄膜具有响应光谱宽、响应速度快、在有效范围内线性好等优点,可以应用于激光能量／功率计。     

基于混沌的扩频通信

针对混沌信号具有的随机性、宽带性、似噪声以及对初始条件的极端敏感性的特点，本文用混沌序列取代扩频通信系统中的伪随机码，在提出并实现一种混沌网络同步化法的基础上，实现了语音、文字和图像的码分多址的扩频通信。用Ｌｏｒｅｎｚ混沌系统对同步和通信的仿真结果表明了本文所述方法的有效性和可靠性。进一步指出了这种通信方式具有简便性和自然的保密性的优点。     

248 nm高反膜抗激光损伤性能

用电子束蒸发法在熔融石英基底上沉积了适用于248nm的HfO2/SiO2高反膜,为提高其抗激光损伤能力,设计并制备了两种保护层,一种是在常规高反膜系的基础上镀制二分之一波长厚度的SiO2保护层,另一种是用Al2O3/MgF2做保护层。测试了3种高反膜样品的激光损伤情况,通过损伤形貌的变化分析了两种保护层使抗激光损伤能力提高的原因以及存在的问题。