共振多光子电离探测芳香烃污染物对比实验研究

本文用两种不同的方法对同期制备的不同浓度的苯、甲苯、二甲苯及其混合气和摩托车尾气三类样品分别进行了对比实验,实验验证了多光子电离所得实验数据的可靠性及其测量精确性,同时可以看出多光子电离方法所具有的快速、实时在线和多组分同时探测的优越性。     

Soft Robotic-Adapted Multimodal Sensors Derived from Entirely Intrinsic Self-Healing and Stretchable Cross-Linked Networks

Flexible sensing technologies that play a pivotal role in endowing robots with detection capabilities and monitoring their motions are impulsively desired for intelligent robotics systems. However, integrating and constructing reliable and sustainable flexible sensors with multifunctionality for robots remains an everlasting challenge. Herein, an entirely intrinsic self-healing, stretchable, and attachable multimodal sensor is developed that can be conformally integrated with soft robots to identify diverse signals. The dynamic bonds cross-linked networks including the insulating polymer and conductive hydrogel with good comprehensive performances are designed to fabricate the sensor with prolonged lifespan and improved reliability. Benefiting from the self-adhesiveness of the hydrogel, strong interfacial bonding can be formed on various surfaces, which promotes the conformable integration of the sensor with robots. Due to the ionic transportation mechanism, the sensor can detect strain and temperature based on piezoresistive and thermoresistive effect, respectively. Moreover, the sensor can work in triboelectric mode to achieve self-powered sensing. Various information can be identified from the electrical signals generated by the sensor, including hand gestures, soft robot crawling motions, a message of code, the temperature of objects, and the type of materials, holding great promise in the fields of environmental detection, wearable devices, human-machine interfacing, and robotics.     

Facile Synthesis of Medium-Entropy Metal Sulfides as High-Efficiency Electrocatalysts toward Oxygen Evolution Reaction

Developing highly efficient and durable electrocatalysts toward oxygen evolution reaction (OER) is an urgent demand to produce clean hydrogen energy. In this study, a series of medium-entropy metal sulfides (MEMS) of (NiFeCoX)₃S₄ (where X = Mn, Cr, Zn) are synthesized by a facile one-pot solvothermal strategy using molecular precursors. Benefiting from the multiple-metal synergistic effect and the low crystallinity, these MEMS show significantly enhanced electrocatalytic OER activity compared with the binary-metal (NiFe)₃S₄ and ternary-metal (NiFeCo)₃S₄ counterparts. Especially, (NiFeCoMn)₃S₄ delivers a low overpotential of 289 mV at 10 mA cm⁻², a decent Tafel slope of 75.6 mV dec⁻¹ and robust catalytic stability in alkaline medium, outperforming the costly IrO₂ benchmark electrocatalyst and the majority of the reported metal sulfide-based electrocatalysts until now. These MEMS with facile synthesis and excellent electrocatalytic performance bring a great opportunity to design desirable electrocatalysts for practical application.     

Combined Magnetic Imaging and Anisotropic Magnetoresistance Detection of Dipolar Skyrmions

Magnetic skyrmions are localized particle-like nontrivial swirls that are promising in building high-performance topological spintronic devices. The read-out functions in skyrmionic devices require the translation of magnetic skyrmions to electrical signals. Here, combined real-space magnetic imaging and anisotropic magnetoresistance studies on dipolar skyrmions are reported. A single skyrmion chain and single skyrmion are observed using Lorentz transmission electron microscopy imaging. Meanwhile, the field, helicity, and skyrmion count dependence of anisotropic magnetoresistance of the Fe₃Sn₂ nanostructures are obtained simultaneously. These results demonstrate that the anisotropic magnetoresistance of skyrmions is independent of the helicity and proportional to the skyrmion count. This study promotes read-out operations in skyrmion-based spintronic devices.     

真丝云纹印花的前准备工序技术总结

针对真丝云纹印花的难度，总结了设计、放样、画稿、制版四个工序中的重点技术，特别是对电脑分色描稿、计算机电子加网制作黑白片等技术与云纹花样的印制效果进行了探索，对生产具有指导作用。     

含豆渣食品的研究

豆渣含有丰富的食物纤维，本试验将豆渣经过脱腥细化处理，制成湿豆渣糊和干豆渣粉，制成含豆渣的桃酥、面条、猪肉丸子。证明添加一定量的豆渣不会影响这些产品的感官质量，并可提高食品中食物纤维的含量。     

滑水临界车速分析及可能采取的解决措施

轮式车辆或起降的飞机在积水的跑道上行驶或滑行时,会因滑水而导致失去行驶方向,其危害是相当严重的.经过大量的实验分析,并在实验的基础上得出了滑水时的车速u=6.34pkm/h,p为轮胎的充气气压(kPa).本文以实验公式为依据,从水流的流速、动量方程、接地区斜楔内动压大小等因素出发,推导出了临界平衡条件即滑水时的临界车速.并得出了车轮轮胎抗压能力最薄弱处变形斜楔内动压的关系以及水深、胎压、胎宽及车速间的相互作用关系,并据此提出了解决此问题的可能方法.     

一种新的直方图核函数及在图像分类中的应用

基于核方法的支持向量机(SVM)以其良好的推广性在图像分类等领域已经得到广泛应用,运用支持向量机的关键是设计有效的核函数。为克服传统核函数较少融合先验知识的弱点,该文提出基于数据驱动的核函数构建方法;并结合词包(BOW)模型,设计了一种基于TF-IDF规则的加权二次卡方(Weighted Quadritic Chisquared, WQC)距离的直方图核函数;在计算直方图之间距离时充分考虑到不同量化区间的不同区分性能,从而增强核函数对不同类别的区分能力。在Caltech101/256等多个经典图像数据集上的分类实验结果验证了该文方法的有效性。     

激光诱导银纳米颗粒薄膜和微结构

利用可见激光诱导化学沉积方法在玻璃基底上制备纳米银薄膜和微结构。玻璃样品池中装满柠檬酸钠和硝酸银的混合透明溶液,当一束可见连续激光正入射样品池一段时间后,在辐照区域的玻璃内壁上便可以形成一层光亮的银膜。银膜沉积的速度受到激光功率密度、激光波长、辐照时间以及混合溶液的浓度等条件的影响。利用X射线衍射、原子力显微镜和拉曼光谱仪等手段对制备的薄膜的成分、表面形貌和拉曼活性等性质进行了表征和分析。利用此方法制备的银膜具有良好的表面增强拉曼散射活性。同时,利用双光束干涉的方法在玻璃基底上诱导出不同周期的银纳米颗粒光栅。     

非晶碲镉汞薄膜的暗电导与光电导

This paper reports the dark conductivity and photoconductivity of amorphous Hg_(0.78)Cd_(0.22)Te thin films deposited on an Al_2O_3 substrate by RF magnetron sputtering.It is determined that dark conduction activation energy is 0.417 eV for the as-grown sample.Thermal quenching is absent for the as-grown sample during the testing temperature zone,but the reverse is true for the polycrystalline sample.Photosensitivity shows the maximum at 240 K for amorphous thin films,while it is higher for the as-grown ...