EPT／BIIR橡胶密封材料制备及其性能

为了探索具备低水蒸气透过系数、低透气系数、低压缩永久变形以及良好耐老化性能的新型橡胶密封材料，鉴于影响并用胶性能的主要因素是共混相容性以及硫化速度，从实现并用胶优势互补角度出发，优选综合性能较好的三元乙丙橡胶（EPT）和溴化丁基橡胶（BIIR），开展了EPT／BIIR共混共硫化技术研究，并开展了DBPMH／HVA-2过氧化物硫化体系在EPT／BIIR并用胶中的应用研究。     

蓝宝石R面上ZnO薄膜的NH3掺杂研究

以NH₃为掺杂源,利用金属有机化学气相沉积(MOCVD)系统在蓝宝石R面上生长出掺氮ZnO薄膜。通过XRD,SEM测量优化了其生长参数,在610℃和在80sccm的NH₃流量下生长出了〈1120〉单一取向的ZnO薄膜。经Hall电阻率测量,得知该薄膜呈现弱p型或高电阻率,并对其光电子能谱进行了研究。     

GC和HPLC分析北豆根多糖的单糖组成的方法比较

采用GC法和HPLC法对北豆根多糖的单糖组成进行分析比较。采用糖腈乙酸酯衍生化—GC法和1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生—HPLC法分别对北豆根多糖的单糖组成进行测定,并评价两种方法的适用性。GC法检测出D-鼠李糖(D-Rha)、D-阿拉伯糖(D-Ara)、D-木糖(D-Xyl)、D-甘露糖(D-Man)、D-葡萄糖(D-Glc)和D-半乳糖(D-Gal);HPLC法检测出D-甘露糖(D-Man)、D-鼠李糖(D-Rha)、D-葡萄糖(D-Glc)、D-阿拉伯糖(D-Ara)、D-半乳糖(D-Gal)、D-木糖(D-Xyl),其中D-阿拉伯糖(D-Ara)和D-半乳糖(D-Gal)的色谱峰重叠。两种方法均检测出6种中性糖组分,对比北豆根多糖的单糖组成分析GC法和HPLC法联用较为适合。     

用鲁米诺-KIO4-Fe(1, 10-phen)32+体系的化学发光法测定痕量铁

本文利用鲁米诺-KIO₄-Fe(1,10-phen)₃²⁺配合物体系产生化学发光反应,建立了测定痕量铁的新的化学发光分析方法.该法以1,10-phen为配位体,铁的检出限为1.6×10^-7g/L,工作曲线响应浓度范围在1×10^-5-1×10^-3g/L.在测定2×10^-4g/L铁的相对标准偏差为3.5%.用于检测工业沉淀BaSO₄中痕量铁获得满意结果.     

声表面波器件用〈110〉取向ZnO薄膜的MOCVD生长

Zn O是具有纤锌矿晶体结构的多功能半导体材料 ,它具有 3 .3 7e V的禁带宽度和高达 60 me V的激子束缚能 ,是很有希望的紫外发光材料 .由于具有 c轴的择优取向性 ,因此目前人们的注意力主要集中在对 c轴取向 Zn O薄膜的特性研究上 [1～ 3] .但其它取向的 Zn O薄膜也可在某些衬底的特定面上 ,通过特定的条件进行生长 ,如〈1 1 0〉取向的 Zn O薄膜可在特定的条件下生长在蓝宝石 R面衬底上[4～ 7] .由于 (1 1 0 )面的 Zn O薄膜具有一些 c轴取向薄膜所不具备或无法比拟的特性 ,如 :机电耦合系数高达6% (C面薄膜的机电耦合系数却不足 1 % )…     

激光驻波场中钠原子沉积图样的理论研究

原子在近共振激光驻波场中受光的作用力汇聚沉积，形成以激光半波长为周期的光栅结构. 利用半经典模型对钠原子束在不饱和驻波场中的运动行为进行了理论研究，用数值方法模拟出在考虑横向温度、纵向速度和自由飞程后钠原子沉积的光栅结构，通过半高宽、对比度对最终沉积图样进行表征，分析了这些因素对沉积的影响，为正在开展的原子光刻实验提供了必要的理论依据. 关键词： 原子沉积 半经典模型 激光驻波场     

激光准直Cr原子束的实验研究

利用多普勒原理对Cr原子束进行横向准直.应用激光感生荧光技术稳定激光器的频率，把激光器的中心频率稳定在偏离Cr原子共振中心频率-5±0.26MHz的位置.根据理论计算出准直激光束的最小尺寸为13.7mm.根据实验数据选择合适的参数，实现利用多普勒原理横向准直Cr原子束，使原子束的横向分布缩小到原来的1/3. 关键词： 激光准直 激光感生荧光稳频 多普勒冷却     

Analysis of Cr atom focusing deposition properties in the double half Gaussian standing wave field

The use of the dipole force on atoms is a new technology that is used to build nanostructures. In this way, a high quality standard nano-grating can be obtained. Based on the semi-classical model, the motion equation is investigated and the trajectories of atoms in double half Gaussian standing wave field are simulated. Compared with the Gaussian standing wave field, the double half Gaussian standing wave can well focus the Cr atoms. In order to obtain this kind of beam, a prism is designed and the experimental result shows that the beam is well generated.     

Structured mirror array for two-dimensional collimation of a chromium beam in atom lithography

Direct-write atom lithography,one of the potential nanofabrication techniques,is restricted by some difficulties in producing optical masks for the deposition of complex structures.In order to make further progress,a structured mirror array is developed to transversely collimate the chromium atomic beam in two dimensions.The best collimation is obtained when the laser red detunes by natural line-width of transition 7S3 → 7P40 of the chromium atom.The collimation ratio is 0.45 vertically(in x axis),and it is 0.55 horizontally(in y axis).The theoretical model is also simulated,and success of our structured mirror array is achieved.     

Broadening of Cr nanostructures in laser-focused atomic deposition

This paper presents the experimental progress of laser-focused Cr atomic deposition and the experimental condition.The result is an accurate array of lines with a periodicity of 212.8±0.2 nm and mean full-width at half maximum as approximately 95 nm.Surface growth in laser-focused Cr atomic deposition is modeled and studied by kinetic Monte Carlo simulation including two events:the one is that atom trajectories in laser standing wave are simulated with the semiclassical equations of motion to obtain the deposition position;the other is that adatom diffuses by considering two major diffusion processes,namely,terrace diffusion and step-edge descending.Comparing with experimental results(Anderson W R,Bradley C C,McClelland J J and Celotta R J 1999 Phys.Rev.A 59 2476),it finds that the simulated trend of dependence on feature width is in agreement with the power of standing wave,the other two simulated trends are the same in the initial stage.These results demonstrate that some surface diffusion processes play important role in feature width broadening.Numerical result also shows that high incoming beam flux of atoms deposited redounds to decrease the distance between adatoms which can diffuse to minimize the feature width and enhance the contrast.