8-R-9苄基-9H-嘌呤衍生物的合成研究

采用 (Ph3 P) 2 PdCl2 为催化剂 ,DMF为溶剂 ,对 8 碘 9 苄基 9H 嘌呤与有机锡试剂RSnBu3 (R=乙烯基、2 噻吩基、2 呋喃基、苯乙炔基和苯基等 )之间的Stille偶合反应进行了研究 ,合成出了5种 8位取代的嘌呤衍生物。在反应温度为 80℃ ,n(8 碘 9 苄基 9H 嘌呤 )∶n (RSnBu3 )∶n〔(Ph3 P) 2 PdCl2 〕 =1 0∶1 2∶0 0 5的较佳工艺条件下 ,产品收率 4 1%～ 91%。用1H NMR、13 C NMR和MS对产物进行了表征     

应用计算机实现选矿自动化

本文就太钢尖山铁矿计算机控制系统的硬件构成，顺控系统的软件编制、模拟调试以及现场调试等方面展开论述。     

黄沙坪矿浮选程控自动给药机的原理及应用

介绍了湖南黄沙坪铅锌矿浮选程控自动给药机的工作原理、系统配置及功能。现场使用表明，浮选程控自动给药机比人工加药降低药剂耗量9－10个百分点。     

化学沉积Ni-P及Ni-Cu-P合金镀层晶化行为的比较

利用DSC和XRD对化学沉积Ni-P及Ni-Cu-P合金镀层的晶化行为进行了比较研究，结果表明：低磷Ni-P镀层直接转变为稳定相Ni3P,而低磷（高铜）Ni-Cu-P镀层则经生成亚稳中间相Ni5P2后再向稳定相Ni3P转变，高磷非晶态Ni-12.1%P(质量分数，下同）和Ni-17.96%Cu-9.29%P合金镀层均先形成亚稳中间相Ni5P2和Ni12P5后，再转变为稳定相Ni3P,但Ni-Cu-P合金镀层转变为亚稳相的温度比Ni-P镀层的高。     

Atmospheric and low pressure shadow masked MOVPE growth of InGaAs(P)/InP and (In)GaAs/(Al)GaAs heterostructures and quantum wells

The shadow masked growth technique is presented as a tool to achieve thickness and bandgap variations laterally over the substrate during metalorganic vapor phase epitaxy. Lateral thickness and bandgap variations are very important for the fabrication of photonic integrated circuits, where several passive and active optical components need to be integrated on the same substrate. Several aspects of the shadow masked growth are characterized for InP based materials as well as for GaAs based materials. Thickness reductions are studied as a function of the mask dimensions, the reactor pressure, the orientation of the masked channels and the undercutting of the mask. The thickness reduction is strongly influenced by the mask dimensions and the reactor pressure, while the influence of the orientation of the channels and the amount of undercutting is only significant for narrow mask windows. During shadow masked growth, there are not only thickness variations but also compositional variations. Therefore, we studied the changes in In/Ga and As/P ratios for InGaAs and InGaAsP layers. It appears that mainly the In/Ga-ratio is responsible for compositional changes and that the As/P-ratio remains unchanged during shadow masked growth.     

Electrostatic polymer processing of isotactic poly(4-methyl-1-pentene) fibrous membrane

Isotactic poly(4-methyl-1-pentene) (P4M1P) is a widely used polymer in industrial applications and specifically, in medical products. Producing micro- or nanofibers would expand the usefulness of P4M1P to a broad range of medical applications. The choice and quality of solvent for the solution used for electrospinning can have a dramatic effect on the spinnability of fibers and on their morphological appearance. In this study, four solvent systems: cyclohexane, cyclohexane/acetone mixture, cyclohexane/dimethyl formamide (DMF) mixture and cyclohexane/acetone/DMF mixture have been investigated. As demonstrated by FE-SEM, electrospun fibers with different morphologies including round, twisted with a roughened texture, curled and twisted-ribbon shapes were formed. The fiber shape and morphology depended strongly on the type and amount of non-solvent used.     

大空域机动巡航导弹的模糊PID控制器设计

针对大空域机动巡航导弹下降转平飞过程中出现的强非线性特点．在俯仰通道设计了模糊PID双模控制方案。以高度误差和该误差变化量为输入．以高度误差为阀限．在高度误差较大时采用响应迅速的模糊控制器．较小时采用稳态精度较高的PID控制器。最后通过仿真表明通过该方案所控制的弹道符合方案弹道．满足设计指标要求。     

基于ISO质量体系认证在线计量数据智能统计和查询

ISO质量体系认证标准要求对计量数据进行计算和评价。公司的信息管理系统可以自动计算统计参数，并可以方便的进行分析和查询，提高企业工作效率，改善产品质量。论文为国家自然科学基金“现代制造质量控制、溯源中若干理论问题与技术基础的研究”(项目号：59735120)中的一部分。     

Channelling studies on the lattice location of B atoms in graphite

In order to obtain information on the lattice location of B atoms in graphite, channelling experiments have been performed at room temperature with a proton beam of an energy of 0.65-0.77 MeV for the 〈0 0 0 1〉 axial channel in highly oriented pyrolytic graphite (HOPG) crystals doped with 0.32 at.% B. The B atoms are detected by measuring α-particles which are emitted as a result of a nuclear reaction ¹¹B(p,α)αα. It is clearly demonstrated that most of B atoms are shadowed behind the 〈0 0 0 1〉 C atomic rows. Taking account of the already reported experimental results on a change of lattice parameters by B-doping, it is concluded that most of B atoms are located at substitutional sites. It is also observed that B-doping introduces lattice strain on the c-plane. In addition, the presence of a small portion of interstitial B atoms is suggested.