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。     

Photothermal Heating-Assisted Superior Antibacterial and Antibiofilm Activity of High-Entropy-Alloy Nanoparticles

Antibacterial elements and non-contact heating abilities have been proven effective for antibacterial and antibiofilm activities, but it remains a challenge to integrate both within one material. Herein, assisted by the high-entropy effect, FeNiTiCrMnCu_x high-entropy alloy nanoparticles (HEA-NPs) with excellent photothermal heating properties for boosting antibacterial and antibiofilm performances are synthesized. Benefitting from the synergetic effect of copper ions released and thermal damage by the HEA-NPs, more reactive oxygen species (ROS) are generated, leading to the rupture of the cell membranes and the eradication of the biofilms. As a result, the antibiofilm efficiency (400 µg mL⁻¹) of the mostly optimized FeNiTiCrMnCu_1.0 HEA-NPs in the marine nutrient medium, which is the worst-case scenario for the antimicrobial material, can be improved from 81% to 97.4% under 30 min solar irradiation (1 sun). The present study demonstrates a new strategy for effectively treating marine microorganisms that cause biofouling and microbial corrosion using HEA-NPs with photothermal heating characteristics as an antibacterial auxiliary.     

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。     

昆虫目标雷达散射截面积特征辅助跟踪算法

害虫迁飞具有规模大、突发性强的特点,会导致病虫害异地大爆发,粮食产量下降,造成重大的经济损失。昆虫雷达是监测迁飞性害虫的一种有效手段。昆虫目标的雷达散射截面积(RCS)较小,回波能量弱,在保证高检测率的同时会带来高虚警率问题,进而导致在目标跟踪的数据关联环节,易受虚假量测的影响出现关联错误。幅度特征辅助跟踪算法利用目标与噪声点迹的幅度差异,可以有效提高目标与噪声的识别度,改善跟踪性能,但是其需要已知目标的RCS起伏模型作为先验信息来计算幅度似然比。因此,该文基于Ku波段高分辨昆虫雷达外场实测昆虫回波数据,分析了昆虫目标的RCS起伏特性,得出Gamma分布可以较好地拟合昆虫目标的RCS统计分布,并将其作为先验信息,推导出Gamma起伏目标在高斯白噪声背景下的幅度似然比。通过在不同信噪比、不同量测噪声及不同起伏模型参数下的仿真结果及性能指标分析,验证了相比于概率数据互联滤波算法(PDAF)算法,目标RCS特征辅助的跟踪算法可以有效提高昆虫目标的跟踪精度。      

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.     

AND:Rubrene发光层的有机电致白光器件

利用9,10-bis(2-naphthyl) anthracene(AND)掺杂rubrene作为器件单一发光层,研制成功单层白光器件。器件在电流密度为140mA/cm2时,电流效率达到5.93cd/A;当电压为21V时,该器件达到最高亮度9300cd/m2。器件发光色坐标为(0.32,0.40),且随着电压的变化发光色度始终处于白光区。这种器件的白色发射是来源于AND(蓝色发射)和rubrene(橙色发散)的混合发射。与此同时,AND和rubrene二者之间会发生Frster能量传递。     

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。