光学多稳系统临界现象的平均场理论

本文唯象地提出了一个光学四稳系统的动力学模型，说明在四隐系数的临界点同样具有类二级相变的特征，进一步指出光学多稳系统都有类似的性质，这使得我们在更大范围内得到了光学非线性耗散系统临界点相变共性。     

水产食品熟食品和水产食品气调包装的研究

本文介绍水产食品、烘烤食品和熟食品的气调包装工艺。从混合气体配气比例、塑料包装材料的气体阻隔性、贮藏温度和包装前食品的卫生指标四个方面因素分析食品气调包装的保鲜效果。通过试验取得一些气调包装食品的保质期。     

Hierarchically Porous Multimetal‐Based Carbon Nanorod Hybrid as an Efficient Oxygen Catalyst for Rechargeable Zinc–Air Batteries

The lack of efficient strategies to address the intrinsic activity, site accessibility, and structural stability issues of metal‐carbon hybrid catalysts is restricting their real‐world implementation on the basis of rechargeable zinc–air batteries. Herein, a dual metal–organic frameworks (MOFs) pyrolysis strategy is developed to regulate the intrinsic activity and porous structure of the derived catalysts, where a Fe₂Ni_MIL‐88@ZnCo_zeolitic imidazolate framework (ZIF), with a hierarchically porous structure, multifunctional components, and an integrated architecture, acts as an ideal precursor to obtain multimetal based porous nanorod (FeNiCo@NC‐P). Benefitting from the synergetic effect of the multimetal components, facilitated reactant accessibility, and the well‐retained integrated structure, the resultant FeNiCo@NC‐P catalyst exhibits an oxygen reduction reaction half‐wave potential of 0.84 V as well as an oxygen evolution reaction potential of 1.54 V at 10 mA cm^–2. Furthermore, the practical application of FeNiCo@NC‐P in the zinc–air battery displays a low voltage gap and long‐term durability (over 130 h at a current density of 10 mA cm^–2), which outperforms the commercial noble metal benchmarks. This work not only affords a competitive bifunctional oxygen electrocatalyst for zinc–air batteries but also paves a new way to design and fabricate MOF‐derived materials with tunable catalytic properties.     

Lead‐Free Polycrystalline Ferroelectric Nanowires with Enhanced Curie Temperature

Ferroelectrics are important technological materials with wide‐ranging applications in electronics, communication, health, and energy. While lead‐based ferroelectrics have remained the predominant mainstay of industry for decades, environmentally friendly lead‐free alternatives are limited due to relatively low Curie temperatures (T _C) and/or high cost in many cases. Efforts have been made to enhance T _C through strain engineering, often involving energy‐intensive and expensive fabrication of thin epitaxial films on lattice‐mismatched substrates. Here, a relatively simple and scalable sol–gel synthesis route to fabricate polycrystalline (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ nanowires within porous templates is presented, with an observed enhancement of T _C up to ≈300 °C as compared to ≈90 °C in the bulk. By combining experiments and theoretical calculations, this effect is attributed to the volume reduction in the template‐grown nanowires that modifies the balance between different structural instabilities. The results offer a cost‐effective solution‐based approach for strain‐tuning in a promising lead‐free ferroelectric system, thus widening their current applicability.     

900MHz高频低损耗声表面波滤波器

介绍了在３６°ＹＸＬｉＴａＯ＿３基片上采用镜像阻抗连接换能器结构研究制作出９００ＭＨｚ高频低损耗声表面波滤波器，插入损耗小于５ｄＢ、带外抑制优于５０ｄＢ。     

New and improved approaches for shared-path protection in WDM mesh networks

This paper investigates the problem of dynamic survivable lightpath provisioning in optical mesh networks employing wavelength-division multiplexing (WDM). In particular, we focus on shared-path protection because it is resource efficient due to the fact that backup paths can share wavelength links when their corresponding working paths are mutually diverse. Our main contributions are as follows. 1) First, we prove that the problem of finding an eligible pair of working and backup paths for a new lightpath request requiring shared-path protection under the current network state is NP-complete. 2) Then, we develop a heuristic, called CAFES, to compute a feasible solution with high probability. 3) Finally, we design another heuristic, called OPT, to optimize resource consumption for a given solution. The merits of our approaches are that they capture the essence of shared-path protection and approach to optimal solutions without enumerating paths. We evaluate the effectiveness of our heuristics and the results are found to be promising.     

基于光纤光栅技术的全光纤单纵模激光器研究进展

实现单纵模光纤激光器的技术难点主要在于如何使谐振腔具有高的模式选择性能,以及如何加入适当的窄带滤波器来辅助选频,而光纤光栅技术在光纤激光器的设计与性能优化方面扮演着十分重要的角色。综合论述了近年来国内外利用光纤光栅产生单波长或多波长单纵模全光纤激光器的主要实现技术,并分析其优缺点,最后给出了总结与展望。     

认知无线电网络中次用户平均吞吐量的优化

协作频谱感知的认知无线电网络中,已有研究表明增加参与协作频谱感知的次用户数量能够提高感知性能,进而提高信道吞吐量。然而,由于信道容量的限制,不断增加参与协作感知的次用户数量并不会使信道吞吐量无限提高,反而会使次用户平均可获得的吞吐量不断降低。针对上述问题,该文以次用户平均吞吐量为优化目标,证明多信道条件下,对于任意给定的融合参数,次用户的平均吞吐量是感知时间的凸函数,并提出交叉迭代算法进行2维优化。仿真结果表明,当信噪比为-10 dB时,次用户使用交叉迭代算法获得的平均吞吐量较已有算法可提高20%以上。     

变频调速在空调系统中的应用

针对人们对生活环境的要求和节能技术的推进,介绍变频空调相对于定频空调节能舒适的优势,通过对变频调速的基本原理、压缩机的定子电压与频率关系的论述,详细分析将变频器引入空调系统的工作原理,结果表明变频空调已进入快速发展期,在我国变频空调将成为空调发展的必然趋势。     

新的非平面Flash Memory结构

提出了一种为在低压下工作的具有较快编程速度的新的非平面的flash memory单元结构,该结构采用简单的叠栅结构并只需增加一步光刻制做出这一新的沟道结构.对于栅长为1.2μm flash单元,获得了在Vg＝15V,Vd＝5V条件下编程时间为42μs,在Vg＝-5V,Vs＝8V条件下的擦除时间为24ms的高性能flash单元,这一新结构的编程速度比普通平面型快闪存储器要快很多.这种新结构flash单元在高速应用场合下具有很好的应用前景.