添加Si3N4纳米粒子的镍磷复合锻工艺及镀层性能研究

通过正交试验法确定了镍-磷-Si3N4纳米粒子复合镀最佳施镀工艺,研究了热处理温度对镀层硬度的影响,对镀层的微观结构进行了分析.     

对于真空系统中e型电子枪光斑的调整的研究

电子束蒸发时电子枪光斑能量的均匀,大小,直接影响着靶材的蒸镀情况和膜层的形成及膜层的表面情况等,本文对e型电子枪光斑的调整进行了分析和研究.     

隐身窗帘和太阳能百叶窗

日本科学家研制成功一种被称为“我能看到你,你却看不到我”的隐身窗帘。这种窗帘是在高透明度的高分子聚合物上蒸镀一层极薄的铝膜,具有反射热线的作用。虽然在这种窗帘上蒸镀的铝膜只有几微米厚,但它足能把太阳光中的大部分可见光反射掉,从而使进入室内     

Ni-P-MgO(CuO)纳米、微米复合化学镀层的制备和性质

为了进一步研究化学镀镍磷复合镀层的性能,在研究了镍磷化学复合镀新配方的基础上,在A3钢片表面分别制备了纳米和微米复合材料镀层N i-P-MgO(CuO).用称重法测定厚度;通过10%NaC l溶液测定其耐腐蚀性;GB5935 86标准贴滤纸法测镀层的孔隙率;MH-3硬度仪测定其硬度.结果表明:在最佳施镀条件下,可得到耐磨性、硬度强于A3钢片、N i-P镀层和N i-P-MgO(CuO)纳米复合镀层的微米复合化学镀层,和光亮致密耐腐蚀性强于A3钢片、和N i-P-MgO(CuO)微米复合镀层,与N i-P镀层相当的N i-P-MgO(CuO)纳米复合镀层.     

表面增强红外光谱的研究进展

在表面科学和电化学领域,表面增强红外吸收光谱受到越来越多的关注,这源于其超高的信号灵敏度和简单的表面选律．对表面增强红外吸收光谱的研究主要采用3种光路进行：透射式、克里斯曼内部全反射式和外部全反射式．红外增强材料的制备分为2大类：千法制备和湿法制备,其中干法制备包括真空蒸镀法与电子溅射法,而湿法制备则包括电镀沉积和无电化学沉积,而纳米壳结构对于红外光具有调谐作用．同时,还介绍了表面增强的2种机理．     

镍-磷-纳米二氧化钛化学复合镀工艺及性能研究

本实验用TiCl4水解法制备了纳米TiO2粉体,然后通过微粒最佳加入量实验确定了最佳工艺配方。采用最佳工艺进行施镀,并测量了镀液的寿命,最后对镀层的组织结构及各方面性能进行了测定。实验结果表明,纳米化学复合镀层的各方面性能要优于普通的镍磷镀层和微米化学复合镀层。     

电子束蒸镀金膜表面黑颗粒物问题的研究

分别用钨坩埚和玻璃碳涂层坩埚蒸镀金膜,采用EDS分析金膜表面黑色颗粒的主要成分。对比金膜表面黑色颗粒分布的密度;根据两种坩埚蒸金膜时的物理学特征不同,研究黑色颗粒产生的机理,解释碳玻璃涂层坩埚蒸金黑色颗粒较多的原因;并利用玻璃碳坩埚采取不同的工艺条件进行对比试验,成功减少了金膜表面的黑色颗粒,为教学实验、真空镀膜工艺和集成电路生产领域蒸镀高质量的金膜提供帮助。     

采用电沉积技术制备铋纳米线阵列

采用电沉积技术 ,通过将铋沉积到氧化铝多孔膜的纳米级微孔内 ,制备铋纳米线阵列材料 .实验发现 ,温度对电沉积过程有显著影响 ,镀液中铋以简单 Bi3 离子形式存在有助于金属铋沉积到氧化铝多孔膜的纳米级微孔内 .由于 Bi3 离子在氧化铝模板的纳米级微孔内扩散困难 ,故采取脉冲电沉积工艺 .XRD分析显示 ,通过电沉积工艺制备出了 Bi纳米线材料     

化学复合镀液中Al2O3微粒分散剂研究

研究用于Ni-P/Al2O3化学复合镀液的Al2O3悬浮液分散剂.将140 nm的α-Al2O3干粉与表面活性剂溶液混合,采用高速机械搅拌和超声波分散Al2O3悬浮液.通过分光光度计测定悬浮液吸光度,用PdCl2测试镀液稳定性;通过孔隙率试验和结合力试验测试化学复合镀层性能,用SEM和EDS测试镀层形貌和化学成分.试验结果表明,阴离子型表面活性剂与非离子型表面活性剂复配,对Al2O3悬浮液的分散稳定有较好的协同效果,适宜的复配分散剂组成为：20 mg/L十二烷基硫酸钠,150 mg/L Tween-80,80 mg/L聚乙二醇.用其配置2 g/L纳米Al2O3悬浮液,静置24 h后吸光度为1.595.该悬浮液配置的镀液稳定性试验时间为165 s,镀速为16.5μm/h.复合镀层中Al2O3粒子呈弥散状分布,Al2O3含量为0.77%.镀层光亮、致密.孔隙率为0.06个/cm2.结合力符合GB/T13913-92标准.该复配分散剂适应于Ni-P/Al2O3化学复合镀液.     

EuFeO3/Eu3Fe5O12混合相纳米颗粒制备及其可见光光催化性质研究

用溶胶-凝胶法制备出EuFeO₃纳米颗粒,通过调节蒸胶温度控制Eu₃Fe₅O₁₂相的生成,X射线衍射测试结果表明当蒸胶温度升高到140℃时,样品会出现EuFeO₃和Eu₃Fe₅O₁₂的混合相.并且随着蒸胶温度的升高,样品的磁性逐渐增强,但可见光下对有机染料罗丹明B的催化降解效率逐渐减弱.当在光催化反应中加入少量H₂O₂后,由于存在非均相芬顿反应,罗丹明B的降解效率有了进一步的提高.     

News and Notices

The 3M Company has claimed a breakthrough in magnetic tape technology by the development of what they call High Energy tapes.     

胶带的色偏振原理及其在演示实验中应用

日常用透明胶带以其各向异性可作为实验室中的简易波晶片来使用,再结合两片偏振片,即可用来探究光学中色偏振现象的各种规律。通过出射光光强、颜色、纯度等各种属性对胶带样品厚度、两偏振片偏振方向的夹角、胶带的拉伸方向与偏振片偏振方向夹角,以及观察角度之间的依赖关系,即可得出胶带的双折射性质;出射光颜色与胶带厚度的关系;出射光色纯度与偏振片角度的关系;出射光颜色与实验者观察角度的关联,并很好地与有关理论符合。将不同层数的胶带黏贴在两片偏光薄片之间以组成不同颜色的色块,即可应用上述规律自制一种创新的趣味性色偏振演示实验仪器。     

不同格式录像带的视频编辑技巧

重点介绍处理不同格式录像带上的视频编辑技巧。     

录像观摩在"中学化学教学论"教学中的作用

录像观摩在中学化学教学论教学中是训练学生化学教学技能不可缺少的一环,同时它还可以加深学生对化学教学原理和方法的认识.教师应开动脑筋,想方设法丰富录像资料,并将录像观摩灵活运用于中学化学教学论的课堂教学中.     

THE DEVON ETV SERVICE

The Devon Educational Television Service was established more than 10 years ago by the former Plymouth Educational Authority. In the production of its own television programmes the aim is to avoid competition with BBC or IBA and to concentrate on topics with a local flavour or to augment national programmes with local material. The provision of material on video cassettes is a service now covering the whole country, as is the 35mm slide, slide/tape and multi‐media pack service. Recent examples give some idea of the range of subjects covered.

Audio tapes are produced in co‐operation with several county advisory teams. Films produced for local needs have found national and international markets. Active support is given to CSE Mode 3 studies in film and television. A working party set up to examine the role of DETVS found that the Service has become an integral and valuable part of the resource network of the county     

录像带的正确选购使用与保管

阐述了录像带的选购、使用和保管方法，既可选购优质录像带，又可避免或减少不必要的损失。     

The Rôle of Tape and Record in Music Teaching

Owing to the acoustic dimension of music the technical media used in music teaching which serve to store and reproduce sounds, namely tapes and records, are of particular significance. Differences between tape and record in the quality of sound reproduction are few, and are primarily due to the type of tape-recorder and gramophone used. The preparation for sound reproduction must not take too much time and this argument favours the use of the record. But the fact that the musical examples needed for one teaching unit usually have to be collected from a great number of records, which is cumbersome and time-consuming, seems to recommend a combined system as the best solution. The production of efficient teaching aids for music in the form of tapes and records ought to be improved. Commercial firms produce records of musical examples; others produce educational records containing musical examples as well as spoken explanations. There are other records sampling musical quotations for a certain field of study.     

A fast motion estimation algorithm for mobile communications

The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder’s performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware.     

A fast motion estimation algorithm for mobile communications

The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder's performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware.