超立方体网络中基于局部安全信息的广播容错路由研究

针对具有错误节点和故障链路的超立方体网络,改进了一种算法实现可靠的容错广播路由。在没有安全结点的不安全的超立方体网络中,将网络分成一系列最大安全子立方体,根据提出的故障链路处理方法和选择广播路由的准则,改进了基于局部安全信息的广播路由算法。证明了根据文中算法,这些最大安全子立方体在满足文中要求的情况下,仍有可能实现可靠的广播路由,有效地提高了信息路由的可靠性。提供了实例介绍文中算法的原理和优点。     

电动负载模拟器的CMAC神经网络复合控制

为增强电动负载模拟器的自适应能力以抵抗系统的非线性、时变参数及运动扰动的影响,提出利用小脑模型神经网络(CMAC)与PID的并联进行控制与调节的控制方法。利用PID控制保证系统的初始稳定性,在小脑模型神经网络引入速度信号和误差信号构成二维参考输入,使系统具有很好的自适应消扰能力,减小了多余力矩的影响。仿真证明了该方法的可行性和有效性,收到了很好的控制效果。     

形式Laurent级数域上交错Oppenheim展开的研究

该文介绍了形式Laurent级数域上交错Oppenheim展开的算法,得到了该展开中数字的强(弱)大数定理、中心极限定理和重对数率,并且研究了这些级数部分和的逼近的度.     

Damping Properties of Blends Based on EVM

The mechanical and damping properties of blends of ethylene-vinyl acetate rubber (VA content >40% wt) (EVM)/ethylene-propylene-diene copolymer (EPDM) and EVM/nitrile butadiene rubber (NBR), both with 1.4 phr BIPB (bis (tert-butyl peroxy isopropyl) benzene) as curing agent, were investigated by dynamic mechanical analysis (DMA). The effect of added polyvinyl chloride (PVC), amido donor N-cyclohexyl-2-benzothiazole sulfonamide (CZ), and dicumyl peroxide (DCP) as a substitute curing agent, on the damping and mechanical properties of both rubber blends were studied. The results showed that in EVM/EPDM/PVC blends, EPDM was immiscible with EVM and could not expand the damping range of EVM at low temperature. PVC was miscible with EVM and dramatically improved the damping property of EVM at high temperature while keeping good mechanical performance. In EVM/NBR/PVC blends, PVC was partially miscible with EVM/NBR blends and remarkably widened the effective damping temperature range (EDTR) from 41.1°C for EVM/NBR to 62.4°C. Curing agents BIPB and DCP had a similar influence on EVM/EPDM blends. DCP, however, dramatically raised the height of tan δ peak of EVM/NBR = 80/20 and expanded its EDTR to 64.9°C. CZ had no obvious influence on the EVM/EPDM blends cured with BIPB. However, a small content of CZ enlarged the tan δ peak of EVM/NBR = 80/20 in both height and width, but at the cost of a deterioration of mechanical performance.     

Influence of Sulfur on Cure Kinetics of Natural Rubber/Sulfur/N-t-butylbenzothiazole-2-sulfenamide (TBBS) System Studied by Rubber Processing Analyzer

Based on the cure characteristics of the Natural Rubber/Sulfur/N–t–butylbenzothiazole– 2–sulfenamide (NR/S/TBBS) system, a kinetic model with induction, curing, and overcure periods was chosen to simulate the cure reaction of this system. Cure-curves reflecting the development of torque were recorded as a function of cure time for NR compounds by a rubber processing analyzer. The cure curves were then non-linear fitted. The results show that the simulated curves fit well with the experimental curves. Rate constant K ₂ for formation of activated crosslink precursors is much higher than rate constant K ₆ for crosslink degradation under the same cure condition. Reaction activation energy E ₂ and E ₆ calculated from K ₂ and K ₆ through the Arrhenius equation showed that E ₆ is higher than E ₂. The increase of sulfur dosage led to the decrease of E ₆ and E ₂, but E ₆ decreased more evidently.     

蜂窝移动定位系统定位精度提高算法的研究进展

提高蜂窝移动定位系统的定位精度是定位技术在CDMA系统中广泛应用的关键。针对提高移动定位精度算法的研究,分别从基本定位算法、非视距传播误差消除算法、抗多径干扰时延估计和抗多址干扰算法、数据融合定位方法等几个方面进行了详细的分析和讨论,综述了该领域的最新研究进展,提出了自己的观点。最后对移动定位精度提高算法研究的未来进行了展望。     

羟基硅酸镁纳米管负载非晶态Co-B催化环己烯氢甲酰化

采用浸渍化学还原法制备羟基硅酸镁纳米管(MgSNTs)负载非晶态钴硼催化剂(Co-B/MgSNTs)。应用X衍射技术(XRD),透射电子显微镜(TEM),X射线光电子能谱仪(XPS),元素分析(ICP)和比表面积(BET)分析等手段对催化剂进行了表征。研究了催化剂对于环己烯氢甲酰化反应的催化活性及循环使用。研究结果表明,具有高比表面积(250 m2·g-1)、较强耐受性和稳定性的MgSNTs可以有效的分散金属粒子,防止活性中心团聚和流失,催化环己烯的转化率为75.8%,醛的选择性为65.8%,实验重复3次以上,催化剂依然保持良好的催化活性和选择性。     

一种节能无线传感器网络

针对无线传感器网络节点能量受限制问题,提出一种节能网络,把监测环境中通电电缆的磁能转化为电能,实现节点能量的自给。采集的能量采用双边调谐阻抗网络传输,通过设计原副边回路参数,令其回路发生谐振来降低自身损耗;组网模式上,用节能静态网络模型代替能耗大的动态组网方式,结合需要,通过切换节点的工作方式来降低能耗。实验证明,能量采集模块一个工作周期采集的能量为10.93 mJ,能够满足传感网络节点工作周期的最大能耗4.68 mJ,验证了节能传感网络可以实现能量自給。     

Co‐Interlayer Engineering toward Efficient Green Quasi‐Two‐Dimensional Perovskite Light‐Emitting Diodes

With respect to three‐dimensional (3D) perovskites, quasi‐two‐dimensional (quasi‐2D) perovskites have unique advantages in light‐emitting devices (LEDs), such as strong exciton binding energy and good phase stability. Interlayer ligand engineering is a key issue to endow them with these properties. Rational design principles for interlayer materials and their processing techniques remain open to investigation. A co‐interlayer engineering strategy is developed to give efficient quasi‐2D perovskites by employing phenylbutylammonium bromide (PBABr) and propylammonium bromide (PABr) as the ligand materials. Preparation of these co‐interlayer quasi‐2D perovskite films is simple and highly controllable without using antisolvent treatment. Crystallization and morphology are readily manipulated by tuning the ratio of co‐interlayer components. Various optical techniques, including steady and ultrafast transient absorption and photoluminescence spectroscopies, are used to investigate their excitonic properties. Photoluminescence quantum yield (PLQY) of the perovskite film is dramatically improved to 89% due to the combined optimization of exciton binding energy and suppression of trap state formation. Accordingly, a high current efficiency of 66.1 cd A^?1 and an external quantum efficiency of 15.1% are achieved for green co‐interlayer quasi‐2D perovskite LEDs without using any light out‐coupling techniques, indicating that co‐interlayer engineering is a simple and effective approach to develop high‐performance perovskite electroluminescence devices.     

Emission Wavelength Tuning via Competing Lattice Expansion and Octahedral Tilting for Efficient Red Perovskite Light-Emitting Diodes

The band-edge electronic structure of lead halide perovskites (ABX₃) is composed of the orbitals of B and X components and can be tuned through the composition and structure of the BX₆ octahedron. Although A-site cations do not directly contribute to near-edge states, the bandgap of 3D metal halide perovskites can be affected by A-cations through BX₆ octahedron tilting or lattice size variation. Here, as confirmed by the Rietveld refinement results of X-ray diffraction characterization, the competition between lattice expansion and octahedral tilting is identified for the first time in emission wavelength tuning when introducing a large A-site cation (C₂H₅NH₃⁺, EA⁺) into 1-naphthylmethylammonium iodide-passivated CsPbI₃ system. The former dominates spectral redshift, while the latter leads to a blueshift of emission peak, which broadens the way to tune the emission wavelength. In addition, excess cations can also passivate the perovskites, leading to a photoluminescence (PL) quantum yield as high as 61%, increased average PL lifetime of 74.7 ns, and a high radiative and non-radiative recombination ratio of 15.7. Eventually, spectral-stable deep-red perovskite light-emitting diode with a maximum external quantum efficiency of 17.5% is realized, which is one of the highest efficiencies without using any light outcoupling and anti-solvent techniques.