关于粒子加速器人身辐射安全联锁系统设计原则的建议

本文讨论了在粒子加速器上的联锁系统设计中应遵循的一些原则,其中建立隔离区、“失效导致安全(Fail-safe)”,使用“硬件”、“多重联锁”、设置急停开关等是最重要的。     

Theory and design of a tapered line distributed photodetector

We present the theory and design of a tapered line distributed photodetector (TLDP). In the previously demonstrated velocity-matched distributed photodetector (VMDP), high electrical bandwidth is achieved by proper termination in the input end to absorb reverse traveling waves, sacrificing one-half of the quantum efficiency. By utilizing the tapered line structure and phase matching between optical waves and microwaves in our analyzed structure, a traveling-wave photodetector is more realizable and ultrahigh bandwidth can be attained due to removal of the extra input dummy load that sacrifices one-half of the total quantum efficiency. To investigate the advantages of TLDP over VMDP, we calculate their electrical bandwidth performances by using an analytic photodistributed current model. We adopted low-temperature-grown (LTG) GaAs-based metal-semiconductor-metal (MSM) traveling-wave photodetectors as example unit active devices in the analytic bandwidth calculation for their high-speed and high-power performances. Both VMDP and TLDP in our simulation are assumed to be transferred onto glass substrates, which would achieve high microwave velocity/impedance and make radiation loss negligible. The simulated bandwidth of a properly designed LTG GaAs MSM TLDP is /spl sim/325 GHz, which is higher than the simulated bandwidth of the LTG GaAs MSM VMDP with an open-circuit input end (/spl sim/240 GHz) and is almost comparable to the simulated bandwidth of an input-terminated LTG GaAs MSM VMDP (/spl sim/330 GHz). This proposed method can be applied to the design of high-bandwidth distributed photodetectors for radio-frequency photonic systems and optoelectronic generation of high-power microwaves and millimeter waves.     

A random switching method for HPWM full-bridge inverter

To overcome the problem of unequal switching loss in power switches, in conventional hybrid pulse width modulation (HPWM) full-bridge inverters, a random switching method for HPWM full-bridge inverters is proposed. The proposed method equalizes switching losses of the four switches, while also providing good output performance     

A network management architecture for robust packet routing in meshoptical access networks

We describe an architecture for an optical local area network (LAN) or metropolitan area network (MAN) access. The architecture allows for bandwidth sharing within a wavelength and is robust to both link and node failures. The architecture can be utilized with an arbitrary, link-redundant mesh network (node-redundancy is necessary only to handle all node failures), and assumes neither the use of a star topology nor the ability to embed such a topology within the physical mesh. Reservation of, bandwidth is performed in a centralized fashion at a (replicated) head end node, simplifying the implementation of complex sharing policies relative to implementation on a distributed set of routers. Unlike a router, however, the head end does not take any action on individual packets and, in particular, does not buffer packets. The architecture thus avoids the difficulties of processing packets in the optical domain while allowing for packetized shared access of wavelengths. We describe the route construction scheme and prove its ability to recover from single link and single node failures, outline a flexible medium access protocol and discuss the implications for implementing specific policies, and propose a simple implementation of the recovery protocol in terms of state machines for per-link devices     

用硫酸铁铵容量法测定钛精矿中二氧化钛含量

样品在过氧化钠熔融、水浸取及盐酸酸化后，在盐酸和硫酸介质中，隔绝空气，用金属铝将钛(Ⅳ)还原至钛(Ⅲ)，以硫氰酸盐为指示剂，用硫酸铁铵标准溶液滴定。     

首钢外购焦炭质量恶化后的高炉生产实践

针对焦炭质量劣化的状况，高炉操作以活跃炉缸为主，从上下部调剂入手，采取疏导煤气、控制合理的实际风速和鼓风动能、缓解焦炭在高温区的粉化等措施，有效地改善了高炉的顺行状况，并逐步恢复高炉指标。     

尿素解吸废液及甲醇残液联合处理工艺的应用

安阳化学工业集团公司(以下简称安化集团)现有2套200 kt/a尿素装置及1套60 kt/a甲醇装置.尿素及甲醇装置在生产过程中会产生大量的尿素解吸废液和甲醇残液,废液中的氨氮(NH3-N)含量和化学需氧量(CODCr)较高,给该公司废水的达标排放带来很大压力.