Organocatalytic Radical Involved Oxidative Cross‐Coupling of N‐Hydroxyphthalimide with Benzylic and Allylic Hydrocarbons

The cross‐coupling reaction between N‐hydroxyphthalimide and various benzylic and allylic hydrocarbons was realized through an organocatalytic radical‐mediated process involving C(sp³) O bond formation using tert‐butyl hydroperoxide (t‐BuOOH) as an oxidant and tetra‐n‐butylammonium iodide [(n‐Bu]₄NI] as a catalyst, during which the phthalimide N‐oxyl (PINO) radical and benzylic and allylic radicals were generated in situ and underwent the selective radical/radical cross‐coupling reaction. This novel method provides a convenient metal‐free approach to the synthesis of O‐alkylated hydroxy imides under mild reaction conditions.

     

Progress in Technologies of Vanadium‐Bearing Titanomagnetite Smelting in PanGang

The smelting of vanadium‐bearing titanomagnetite by blast furnace was very difficult because the content of TiO₂ of blast furnace slag could amount to 20‐25%. After long term development and continuous improvement, special intensified smelting technologies for vanadium‐bearing titanomagnetite by blast furnace were obtained and improved gradually. With the improvement of beneficiated material and equipment, smelting intensity has been increasing gradually and the highest comprehensive smelting intensity that is fuel comsumption per unit useful volume per day reached 1.45t/(m³·d). Technical‐and‐economic indexes of blast furnace have also been increasing remarkably. The highest monthly utilization coefficient exceeded 2.7t/(m³·d) on the condition that the burden total ferrum grade was only about 50%.     

Development and Application of Magnetic Segregation Feeder in Sintering Machine

The size segregation of sintering materials in a chute flow is utilized to prepare well‐bedded feedstock for sintering quality improving, and magnets are installed below the chute to enhance size segregation. By the braking role of magnetic force, the particles of different sizes which poured down to sloping chute are separated:the coarse particles drop to the far‐side of the sloping chute and the fine particles drop near the sloping chute. As the sintering pallet is continuously moving, the coarse particles are distributed into the lower portions and the fine particles are aggregated on the top of the layer..By using the non‐contacting magnetic force,the technique of magnetic segregation feeding overcomes a series of defects such as adhering and wearing in the existing segregation feeding devices. and the device is characterized by simple structure, easy operation, no need of energy,and safety, etc. Discrete element method (DEM) simulations are carried out to explore the optimal arrangement of the magnets.The simulations show that proper magnetic field can significantly enhance the segregation,and the simulation results are in good agreement with the experiments and industrial systems designed with consultation to the results.Depend on those,the technique of magnetic segregation feeding have been developed and applied in the three sintering line of Baoshan Iron & Steel Co., Ltd..The results of industrial application show that the distributions of particles, carbon and FeO in sintering layer have been remarkably improved. In guaranteeing to the quality of sintering ore materials, the productivity of sintering strand raised 2.1% and the fuel ratio decreased 1.7%.     

多出救点、多物资、多救助点的救灾物资调拨模型研究

在自然灾害或其它突发事件发生以后,国家需要根据其破坏程度启动相应等级的应急响应并调拨救灾物资进行紧急救援。衡量救援效果的两个最通常的指标是应急时间和应急成本,目前大部分的物资调拨模型都是单一物资唯一受灾点以多目标规划为主,直接考虑救灾的出救点对灾害发生地的救援物资调拨与路径问题。但在实际的救灾过程中,面对紧急的灾害事件,受灾点的物资的需求都是多样的,灾害救助点很有可能也是多个,并且首先应该是在最短的允许时间内将救灾物资调运到现场,而成本与此目标相比要次之,它需要结合灾害发生时的现实情况做出最优决策。为此,文章结合实际的救灾物资调拨情况,给出了一种多出救点、多物资以及多救助点约束条件下,受灾点需求物资到达时间最短的物资调拨模型,并通过实验验证了可行性。     

一种Ka波段三路波导功率分配/合成器的设计

提出了一种波导三路功分器结构,该功分器采用E面T型缝隙耦合结构来实现功分比的调节。通过调节耦合缝隙以及感性膜片,使输入阻抗匹配并且实现等功率同相位的三路功分输出。为了实现功率合成,采用对称的两个三路功分器进行背靠背级联实现功率合成网络,仿真结果显示出良好的驻波效果和极低的插损。最终对加工出的实物进行测量,在32.5~36 GHz频段内实现了输出功率幅度不平衡度小于0.5 dB的良好效果。通过背靠背连接两个功分器实现了在33.3~35.3 GHz带宽内插损小于0.3 dB的功率分配/合成网络。     

高密度PBGA组件的模态试验与仿真研究

为探索高密度板级组件的动态特性,设计了带菊花链的PBGA(塑封焊球阵列)组件,采用模态试验和有限元仿真方法分别获得PBGA组件的模态参数,分析了不同固支方式对PBGA组件一阶固有频率的影响.研究了边6点固支条件下各阶阵型特性并提出了元器件抗振布局设计的原则,结果表明:6螺钉支撑将显著提高组件的一阶固有频率,从两螺钉的1...     

基于HyperLynx的断路器状态监测无线节点PCB信号完整性分析

信号完整性问题在断路器状态监测无线节点PCB板设计中越来越明显,解决其信号完整性问题越来越重要.本文利用HyperLynx软件针对PCB板产生的反射和串扰问题进行布线前建模仿真和PCB布线后仿真分析后,将反射产生的过冲幅值降低至约100 mV,将串扰产生的过冲幅值控制在约60 mV.仿真结果表明,建立的反射、串扰模型适...     

偏压条件对光耦合器总剂量辐照效应的影响

通过对不同偏压条件对光耦合器总剂量辐照效应的影响进行研究,结果发现随着总剂量的增加,光耦合器电流转换率CTR会降低60％ ～ 80％,且输入低电流时光耦合器总剂量辐照损伤更严重,其原因可能是输入低电流时光耦合器内部发光二极管辐照过程中更容易产生非发光陷阱所致.     

基于HyperLynx的断路器状态监测无线节点PCB设计

断路器状态监测无线节点PCB设计中遇到的高频高速信号产生的信号完整性问题越来越突出.使用IBIS模型和Hyperlynx仿真软件对该节点PCB板布线进行仿真,仿真结果表明经过手工调整布线后PCB板的信号传输产生的近端串扰约为400 mV,而自动生成PCB布线设计产生的近端串扰约为1 000 mV,满足不了高速PCB设计...     

浅谈建筑技术科学与生态人居环境建设

本文阐述了建筑技术科学在创造良好的生态人居环境过程中的重要性,并具体介绍了相关的建筑科学技术方法。