窦平平:探求摧毁问题的答案

<正>女性建筑师1作为一名女性建筑师,国内外的女性建筑师中。你最钦佩哪一位?欣赏的建筑师很多,好像基本都是男性。近来关注一位加拿大女建筑师,Lateral Office的洛拉·谢泼德(Lola Sheppard),她的设计扎根于地广人稀又极度寒冷的地区,注重对资源和物流的分析,从基础设施着眼,采用类型化思维,最后的设计在尺度和物质层面非常微小,而力度和效应很大,非常有启发。如恩设计的胡如珊女士,有敏锐细腻的洞察力,有对文化和传统的执着,也有对市场和资源的判断力,呈     

Tunable features of magnetoelectric transformers - [letters]

We have found that magnetostrictive FeBSiC alloy ribbons laminated with piezoelectric Pb(Zr,Ti)O₃ fiber can act as a tunable transformer when driven under resonant conditions. These composites were also found to exhibit the strongest resonant magnetoelectric voltage coefficient of 750 V/ cm-Oe. The tunable features were achieved by applying small dc magnetic biases of -5 les H_dc les 5 Oe. The features include 1) a high voltage gain of -55 les V_gain les 55; and 2) a large current-to-voltage conversion of -2000 les alpha_I-V les 2000 (V/A). The tunable transformer features can be attributed to large changes in the piezomagnetic coefficient and permeability of the magnetostrictive phase under H_dc.     

Superior ultra-thin nanoporous g-C3N4 photocatalyst embedded with S quantum dots: a non-metal Z-scheme visible-light composite

Journal of Materials Science - The replacing and surpassing of some functions of traditional metal-based photocatalysts by low-cost and high-efficiency non-metal semiconductor materials have become...     

Structural Optimization Design of a Typical Adhesive Bonded Honeycomb-Core Sandwich T-joint in Side Bending Using Multi-Island Genetic Algorithm

Applied Composite Materials - Sandwich structure T-joints are increasingly broadly applied in aviation and aerospace industries due to the need for lightweight design. This paper deals with the...     

虾青素油对核桃油抗氧化性及货架期的影响

向核桃油中添加虾青素油,采用Schaal烘箱法,以过氧化值和酸价为指标,优化了虾青素油添加量,同时考察了适量虾青素油对核桃油皂化值、碘值等理化指标和维生素E、多酚含量以及脂肪酸组成的影响,并根据Arrhenius经验公式对核桃油的货架期进行预测。结果表明:虾青素油添加量为2%时,核桃油多酚、维生素E含量分别为未添加的1. 5、3. 17倍,能显著增强核桃油的抗氧化能力,对抑制酸败也有一定效果。在虾青素油添加量为2%时,核桃油在20℃的货架期与对照相比延长了16 d以上;当核桃油中添加0. 02%TBHQ和2%虾青素油时,其20℃的货架期为480 d,与单独添加0. 02%TBHQ的核桃油相比延长了48 d。因此,通过添加适量的虾青素油,可有效增强核桃油的抗氧化性,延长核桃油的货架期。     

超临界CO2中马来酸酐和乙酸乙烯酯的共聚合

以超临界CO<,2>为反应介质进行了马来酸酐(MA)和乙酸乙烯酯(VAc)的共聚合,制备了不同结构的MA和VAc共聚物[P(MA-co-VAc)],研究了该聚合及产物的性能.结果表明:单体配比和反应压力对产物的形态影响较大,当n(VAc)/n(MA)为1:1,反应压力大于或等于15 MPa时,可制得P(MA-co-VA...     

Giant Piezoelectricity of Ternary Perovskite Ceramics at High Temperatures

Here, novel ferroelectric ceramics of (0.95 ? x)BiScO₃‐xPbTiO₃‐0.05Pb(Sn_1/3Nb_2/3)O₃ (BS‐xPT‐PSN) of complex perovskite structure are reported with compositions near the morphotropic phase boundary (MPB), and which exhibit a piezoelectric coefficient d₃₃ = 555 pC N^?1, a large‐signal coefficient $d_{33}^{?}$ ≈ 1200 pm V^?1 at room temperature, and a high Curie temperature T_C of 408 °C. More interestingly, this ternary system exhibits a giant and stable piezoelectric response at 200 °C with a large‐signal $d_{33}^{?}$ ≈ 2500 pm V^?1, matching that of the costly relaxor‐based piezoelectric single crystals at room temperature. The mechanisms of such giant piezoelectricity and its characteristic temperature dependence are attributed to the spontaneous polarization rotation and extension under an electric field and the MPB‐related phase transition. The findings reveal that the BS‐xPT‐PSN ceramics constitute a new family of high‐performance piezoelectric materials suitable for electromechanical transducers that can be operated at high temperatures (at 200 °C, or higher).     

第三辑：独立建筑师——戴璞：对自己的实践时刻保持警惕

“80后”是我国依法执行计划生育后出生的一代人,多为独生子女,面临的生活、成长、文化发展问题曾受到社会的担忧。他们在变革的社会中成长起来,承担着来自现实和心理上的双重压力。轻狂、张扬、离经叛道、“垮掉的一代”等都曾是大众贴在80后身上的标签。如今,首批80后已迈进30岁门槛,而立之年,首批80后是否已独立起来？     

低时延传输的ERDQN数据调度算法

针对车载网络、远程医疗、工业控制等领域需要低时延、高可靠性的网络传输应用场景,提出了一种经验回放的DQN(experience replay DQN,ERDQN)数据传输调度算法。该算法的主要目的和任务是降低网络时延和提高网络传输的稳定性。ERDQN算法在最后期限感知的传输协议(deadline-aware transport protocol, DTP)的基础上优化了发送端的排队策略,充分考虑了数据块的优先级和截止日期(Deadline),将其作为计算进入等待队列顺序的重要因素,解决了数据块丢失Deadline的问题,降低了网络传输的排队延迟;同时在拥塞控制方面以当前时刻网络传输状态为特征向量,预测下一时刻网络传输状态参数,并赋予不同的奖励因子进行评估,通过ERDQN网络的迭代学习,自动调整到适合当前网络传输的最优参数,在后续的网络链路传输过程中,平均传输速率高且稳定,缓解了网络拥塞和传输不稳定的问题,降低了网络传输时延。实验结果表明ERDQN算法的平均排队时延和传输时延远远低于传统拥塞控制算法(Reno算法),在质量系数(quality of experience, QoE)方面远远高于传统的拥塞控制算法,能够最大程度减少网络传输速率波动、降低丢包率,提供稳定可靠的传输。     

基于VMD-SVD的拉曼分布式光纤测温系统降噪方法

针对分布式光纤测温系统，其产生的包含温度信息的后向拉曼散射信号极其微弱，因此极易被白噪声掩盖的问题。本文设计了一种基于VMD SVD联合降噪算法，并提出通过对构造的仿真信号做降噪对比实验，以更优的降噪性能指标选取该算法的重要参数。实验表明，将该联合算法及EMD、VMD、EMD-SVD算法分别用于多组测试信号降噪时，VMD-SVD降噪算法相较于EMD算法有均有15 dB以上提升，相较于VMD算法有均有9 dB以上的提升，最后相较于EMD-SVD算法也均有1 dB以上提升，最后将上述算法应用于分布式光纤测温系统测量的多组后向拉曼散射信号降噪时，VMD-SVD降噪算法也能最有效的消除该信号的白噪声，为后续高质量测温奠定基础。