Synthesis and photoluminescence properties of wash-board belt-like ZnSe nanostructures

Washboard belt-like zinc selenide （ZnSe） nanostructures are successfully prepared by a simple chemical vapor deposi- tion （CVD） technology without catalyst. The phase compositions, morphologies and optical properties of the nanos- tructures are investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high-resolution transmis- sion electron microscopy （HRTEM） and photoluminescence （PL） spectroscop, respectively. A vapor-liquid mecha- nism is proposed for the formation of ZnSe belt-like structures. Strong PL from the ZnSe nanostructure can be tuned from 462 nm to 440 nm with temperature varying from 1000 ℃ to 1200 ℃, and it is demonstrated that the washboard belt-like ZnSe nanostructures have potential applications in optical and sensory nanotechnology. This method is ex- pected to be applied to the synthesis of other II-VI groups or other group＇s semiconducting materials.     

新型预硫化型重整预加氢催化剂的工业应用

根据重整预加氢工业装置及所需催化剂的特点,通过自主研发的器外预硫化工艺及硫化剂配方开发出了新型预硫化型重整预加氢催化剂DZF-1。在国内某炼油厂500 kt/a重整预加氢装置进行工业应用,表明该催化剂具有简化开工程序、可省去干燥脱水过程、节省器内硫化所需的注硫设施、缩短开工时间、减少环境污染及催化剂硫化完全等优点。与氧化型催化剂硫化相比至少节省24 h开工时间,活化开工时催化剂能够逐级释放H_2S,使循环氢中H_2S含量在理想范围内,整个活化开工过程反应器床层最高温升小于15℃。工业运转表明在其他工艺参数相当条件下,与上周期国内某同类型催化剂相比平均反应温度降低10~15℃。     

北部湾盆地涠西南凹陷富砾型和富砂型湖底扇沉积特征差异分析

北部湾盆地涠西南凹陷在流沙港组一段湖底扇中发现了储量较大的油气资源,为了查找出不同油田湖底扇开发效果差别较大的原因,依据岩心、分析化验资料、测井和地震资料,将研究区湖底扇划分为富砾型和富砂型2种湖底扇,并从岩石学特征、粒度、沉积构造和砂体厚度等沉积特征进行了对比分析。研究认为,古地貌和物源供给类型是造成其沉积特征差异的主要原因。同时总结出了2种湖底扇的沉积模式,重力滑塌是富砂型湖底扇主要的触发机制,构造运动是富砾型湖底扇主要的触发机制。2种湖底扇都具有良好的生储盖组合,但富砾型湖底扇由于物性较差,勘探有利方向是寻找次生孔隙发育带;富砂型湖底扇由于储层物性较好,勘探有利方向是寻找有效圈闭。     

Cherenkov radiation with arbitrary azimuthal mode number excited in a plasma-filled slow-wave waveguide

On the basis of the reference [1], excitation of Cherenkov radiation with arbitrary azimuthal mode number by a thin annular relativistic electron beam in a plasma-filled dielectric-lined slow-wave waveguide is studied in this paper. A determinantal dispersion equation is obtained. This general dispersion equation is valid for arbitrary azimuthal mode number, and the growth rate of the wave is derived from it. Finally, the effects of the background plasma density on the dispersion relation, the background plasma density and the electron beam radius on the growth rate of the wave are presented. Formulas and results offerd in this paper are general, and are of particular value of reference to the beam-wave interaction in azimuthally unsymmetrical slow-wave waveguide.     

Increasing Reliability in Cable-Free Radio LANs Low Level Forwarding in HIPERLAN

Radio LANs are emerging in the computing world. They are supported by distinct configurations: on the one hand radio LANs with base stations and a wired backbone, on the other hand radio LANs implementing Intra-forwarding. Adding a new node in a radio LAN with Intra-forwarding, increases the reliability, while this reliability decreases with ad hoc or hub configurations. This advantage of Intra-forwarding is quantified. Intra-forwarding, as defined in the HIPERLAN standard, is based on a hop-by-hop policy and link check procedures. It is shown how point-to-point packets and broadcast packets are forwarded. The three basic components of Intra-forwarding needed to build and update the Intra-forwarding database are described. The originality of this approach is the use of multipoint relays which enable better scalability. The correctness of the Intra-forwarding protocol is proved and its cost is evaluated.     

Mlcrolasers based on silica microspheres

Light can be confined efficiently in the high-Q, small-volume whispering-gallery-modes observed in silica microspheres. By coupling these microspheres to eroded optical fibers and fiber tips, direct mapping of the whispering-gallery modes has been achieved and the mode numbers have been assessed. The properties of these modes have allowed us to obtain laser action with very low thresholds in Nd-doped silica microspheres. Further projects in the field of non-linear optics and cavity quantum electrodynamics are described.     

基于自适应控制电路实现的宽带高性能频率源

基于自适应控制技术,在宽带捷变频频率合成器的设计方案中同时引入自动调节滤波电路和带温度预校准功能的自动电平控制电路,有效降低了输出信号杂散,提高了输出信号的功率平坦度, 相比传统的利用分段滤波方式实现的宽带频率源,减小了模块体积。文中不仅详细介绍了这2个电路的实现过程,还从易于工程实现的角度出发,着重介绍了一些能有效降低调试工作量的方法。设计所得的频率合成器输出频率1 000 MHz~1 900 MHz,步进2 MHz,在–45 ℃~ +85 ℃的温度范围内,实现了杂散抑制优于–70 dBc,输出功率10 dBm±0.3 dBm的技术指标。     

我国浮式生产储油装置的研制与开发

我国自主研制了8艘浮式生产储油装置(FPSO)。依托这8艘FPSO,成功开发了10个海上油田,其中7个为年产油100×104m3以上的油田。在FPSO研制过程中,共申请了12项专利,制定了多项技术标准。FPSO的研制促进了相关学科的发展与人才培养,FPSO已成为海洋石油开发的战略性技术。目前中国海油3 900多万吨油当量的年产量中,75%的产能依靠FPSO支持。在研制FPSO过程中,已掌握了FPSO设计、建造的许多关键技术,并取得了多单元复杂系统总体优化设计技术、大型浮体浅水效应技术**、抗冰设计方法和抗强台风永久性系泊系统设计技术等4项核心技术的重大突破。这些关键技术与核心技术的掌握和突破,以及它们的成功应用,使FPSO在我国海洋石油工业发展进程中起到了关键作用。我国已成为世界上使用FPSO最多的国家之一,也是设计与建造FPSO最多的国家之一。我国的FPSO总体技术已达到当今国际先进水平。     

CNG汽车加气站国产设备使用情况研究（I）

CNG汽车加气站设备是加气站安全高效运行的物质基础。通过调查研究及理论分析，咨询专家，查阅标准文献，借签国外先进技术水平，客观分析了国产CNG汽车加气站设备的现状，并从设备的技术性、可靠性、安全性、可维修性和经济性等方面找出了与国外同类设备的差距，进而得出改进建议：①加强CNG汽车加气站设备关键技术攻关力度；②加强CNG汽车加气站设备专用检验设备的开发研究迫在眉睫；③严把压力容器类设备制造资格关；④加快制订和完善CNG汽车加气站设备国家标准的步伐；⑤选择储气形式应因地制宜；⑥尽快建立区域性的CNG汽车加气站设备维修服务企业和设备操作维护人员培训基地；⑦ CNG汽车加气站关键设备的国产化率亟待进一步提高；⑧加强行业管理，形成集团化生产。最后分析了CNG汽车加气站设备选型及安全风险评价基本原则，以及 CNG汽车加气站设备技术水平改进的关键系统和关键部件。     

CNG汽车加气站国产设备使用情况研究(I)

CNG汽车加气站设备是加气站安全高效运行的物质基础。通过调查研究及理论分析,咨询专家,查阅标准文献,借签国外先进技术水平,客观分析了国产CNG汽车加气站设备的现状,并从设备的技术性、可靠性、安全性、可维修性和经济性等方面找出了与国外同类设备的差距,进而得出改进建议:①加强CNG汽车加气站设备关键技术攻关力度;②加强CNG汽车加气站设备专用检验设备的开发研究迫在眉睫;③严把压力容器类设备制造资格关;④加快制订和完善CNG汽车加气站设备国家标准的步伐;⑤选择储气形式应因地制宜;⑥尽快建立区域性的CNG汽车加气站设备维修服务企业和设备操作维护人员培训基地;⑦CNG汽车加气站关键设备的国产化率亟待进一步提高;⑧加强行业管理,形成集团化生产。最后分析了CNG汽车加气站设备选型及安全风险评价基本原则,以及CNG汽车加气站设备技术水平改进的关键系统和关键部件。