Study on the Relationship between Structure of Supramolecular Ion Material and Performance of Humidity Sensing

相对湿度是许多领域的关键参数，环境湿度与人们的生活密切相关，因此对湿度进行测量和控制是各个领域中值得关注的问题之一. 在前期的研究中，作者制备了一种新型的超分子离子材料（SIM），它是由基于咪唑的双阳离子（如1,10-双（3-甲基咪唑-1-基）癸烷，C10(mim)2）和电活性二阴离子（如2,2\'-连氮基-双（3-乙基苯并噻唑啉-6-磺酸），ABTS）组成的，发现其对湿度具有敏感且快速的响应. 在此基础上，本文制备了6种不同碳链（C4，C6，C8，C10，C12，C14）的咪唑基化合物，发现其中3种（C10，C12，C14）可与ABTS形成水稳定的SIM. 循环伏安法、计时电流法以及石英晶体微量天平表征了这些超分子离子材料的湿度传感性能，发现基于C12的SIM具有最佳的湿度传感性能. 同时，SEM结果显示随着碳链的增加，离子材料的厚度变薄并且形态变得不规则. 因此，作者认为疏水作用和材料比表面积均会影响湿度传感的灵敏度. 本研究为发展新的湿度响应的离子传感材料奠定了基础.Humidity measurement and control is one of the most notable issues in various areas, such as climate, industry, agriculture, electronics, especially human comfort and health. In our previous study, we have found that a new kind of supramolecular ionic material (SIM), consisting of an imidazolium-based dication (e.g., 1,10-bis(3-methylimidazolium-1-yl) decane, C10(mim)2) and electroactive dianionic (e.g., 2,2\'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS), shows ultrasensitive and ultrafast response towards humidity sensing. Herein we prepared six kinds of imidazolium-based dications with different carbon chain lengths (i.e., C4, C6, C8, C10, C12, C14), and found that three of them (i.e., C10, C12, C14) could form water-stable SIM with ABTS. Cyclic voltammetry, chronoamperometry and quartz crystal microbalance were used to characterize the humidity sensing performance of these supramolecular ionic materials. The results show that the C12-based SIM has the best humidity sensing performance compared with the other two kinds of SIM. Moreover, SEM images show that the thickness of the ionic material became thinner with the increase of the carbon chain length. We, thus, conclude that both the hydrophobic interaction and the specific surface area of SIMs would contribute to the performance of humidity response. This paper would lay the foundation for the development of new ionic compound for humidity sensing.This research was supported by the National Natural Science Foundation of China (No. 21475138).作者联系地址：1. 湘潭大学化学学院，环境友好化学与应用教育部重点实验室，湖南 湘潭 411105；2. 北京分子科学国家实验室，中国科学院化学研究所活体分析化学重点实验室，北京 100190Author's Address: 1. Key Laboratory of Environmental Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China; 2. Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, the Chinese Academy of Sciences, Beijing 100190, China通讯作者E-mail：[email protected]

Mathematical model and optimization for underwater friction stir welding of a heat-treatable aluminum alloy

During the friction stir welding (FSW) of heat-treatable aluminum alloys, the welding thermal cycles tend to cause a local softening in the joints and thus lead to a degradation in joint properties. Underwater FSW has been demonstrated to be available for the strength improvement of normal joints. In order to obtain the optimum welding condition for underwater FSW, a 2219-T6 aluminum alloy was underwater friction stir welded and a mathematical model was developed to optimize the welding parameters for maximum tensile strength in the present study. The results indicate that a maximum tensile strength of 360. MPa can be achieved through underwater FSW, higher than the maximum tensile strength obtained in normal condition.</p

Self-hold welding tool and technological method for friction stir and lap welding

本发明公开了一种搅拌摩擦搭接焊接的自持式焊具和工艺方法，属于搅拌摩擦焊技术领域。所述自持式焊具的尺寸根据上搭接板和下搭接板的厚度来确定；搅拌摩擦搭接焊接时，首先将上搭接板和下搭接板从上至下叠放组成搭接结构，并用夹具对其进行紧固定位；然后移动自持式焊具至焊接起始位置，并使其上轴肩低于上搭接板上表面0-0.3mm，随后焊机主轴旋转并沿既定焊接路径对搭接结构实施搅拌摩擦搭接焊接。本发明解决了背部无法放置支撑垫板的搭接结构的搅拌摩擦搭接焊接问题

a cuda-mpi algorithm for the fast fourier transform on the hexagon and its implementation

本文研究六边形区域上快速傅里叶变换(FFTH)的CUDA-MPI算法及其实现.首先,我们通过充分利用CUDA的层次化并行机制及其库函数,设计了FFTH的高效率的CUDA算法.对于规模为3&times;2048~2的双精度复数类型数据,我们设计的CUDA程序与CPU串行程序相比可以达到12倍加速比,如果不计内存和显存之间的数据传输,则加速比可达40倍;其计算效率与CUFFT所提供的二维方形区域FFT程序的效率基本一致.在此基础上,我们通过研究GPU上分布式并行数据的转置与排序算法,优化设计了FFTH的CUDA-MPI算法.在3&times;8192~2的数据规模、10节点&times;6GPU的计算环境下,我们的CUDA-MPI程序与CPU串行程序相比达到了55倍的加速;其效率比MPI并行版FFTW以及基于CUFFT本地计算和FFTW并行转置的方形区域并行FFT的效率都要高出很多.FFTH的CUDA-MPI算法研究和测试为大规模CPU+GPU异构计算机系统的可扩展新型算法的探索提供了参考.In this paper,we study the parallel algorithm based on CUDA and MPI for the Fast Fourier Transform on the hexagon(FFTH) and its implementation.Firstly,we design a CUDA FFTH algorithm by utilizing the hierachical parallelization mechanism and the build-in CUFFT library for classic rectangular FFTs.With respect to the serial cpu program,our CUDA program achieves 12x speedup for 3*2048~2 double-precision complex-to-complex FFTH.If we ignore the PCI between main memory and GPU device memory,around 30x40x speedup can be even achieved.Although the non-tensorial FFTH is much more complicated than the rectangular FFT,our CUDA FFTH program gains the same efficiency as the rectangular CUFFT.Next,efforts are mainly contributed to optimization techniques for parallel array transposition and data sorting,which significantly improve the efficiency of the CUDA-MPI FFTH algorithm.On a 10-node cluster with 60 GPUs,our CUDA-MPI program achieves about 55x speedup with respect to the the serial cpu program for 3*8192~2 complex-to-complex double-precision FFTH,and it is more efficient than the MPI parallel FFTW.Our research on the CUDA-MPI algorithm for FFTH is beneficial to the exploration and development of new parallel algorithms on large-scale CPU-GPU heterogeneous computer systems

空间导航的测量及其在认知老化中的应用

空间导航是日常生活所必需的高级认知功能,参与空间导航的海马及内嗅皮层等脑区易受到老化的影响并导致结构萎缩或功能紊乱。早期研究多利用动物实验、纸笔测验、现实环境等实验范式考察老年人的空间导航老化特点。由于具有与现实环境相似的场景、兼容磁共振成像扫描以及导航者可以与场景交互等优点,虚拟现实技术被越来越多地被应用到空间导航的老化研究中,并进一步揭示了海马等内侧颞叶脑区在空间导航老化中的重要作用

Measurement of spatial navigation and application research in cognitive aging

空间导航是日常生活所必需的高级认知功能,参与空间导航的海马及内嗅皮层等脑区易受到老化的影响并导致结构萎缩或功能紊乱。早期研究多利用动物实验、纸笔测验、现实环境等实验范式考察老年人的空间导航老化特点。由于具有与现实环境相似的场景、兼容磁共振成像扫描以及导航者可以与场景交互等优点,虚拟现实技术被越来越多地被应用到空间导航的老化研究中,并进一步揭示了海马等内侧颞叶脑区在空间导航老化中的重要作用。</p

Welding with trailing extrusion device for friction stir welding and welding with trailing extrusion method thereof

本发明属于搅拌摩擦焊领域，具体地说是一种用于搅拌摩擦焊的随焊挤压装置及其随焊挤压方法，装置包括支座、支撑臂、施力弹簧和挤压轮，支座通过螺栓与搅拌摩擦焊机的静止轴套相连接，使该装置固定于焊机上；支撑臂呈L型，与施力弹簧一起，通过销轴与支座相连接；挤压轮连接在L型支撑臂的末端，通过主轴向下移动向被焊工件施加压力。采用本发明的随焊挤压装置焊接宽度较大或较小的金属板材，能够有效降低卡具的制造成本，简化焊前装卡过程，增大焊具的施焊空间，从而保证了焊缝的优质成形并拓宽了搅拌摩擦焊技术的应用范围

Thermal-mechanical coupled simulation on residual stress and distortion of high-strength aluminum alloy sheet after friction stir welding

针对航空领域中常用的7B04高强铝合金,基于剪切摩擦生热理论,建立了适用于薄板搅拌摩擦焊(FSW)过程的自适应热源模型,利用有限元软件MSC.Marc建立了FSW过程的热力耦合有限元模型,并通过子程序二次开发,将建立的热源模型载入到有限元模型中,对7B04铝合金薄板的FSW过程进行瞬态热力耦合模拟。预测并分析了FSW过程中铝合金板材内部的温度分布与演化、焊接接头附近区域的残余应力分布及板材的最终变形情况,通过开展FSW工艺试验从温度场和残余应力两方面对模型的可靠性和模拟结果的准确性进行了验证。此外,利用经过验证的有限元模型对搅拌头机械载荷在残余应力和变形中的影响作用进行了深入分析

一种搅拌摩擦焊焊具在高转速焊接中的应用

本发明公开了一种搅拌摩擦焊焊具在高转速焊接中的应用，属于搅拌摩擦焊领域。所述焊具由夹持体、轴肩和搅拌针所构成，轴肩的端面为内凹型,且在该内凹端面上加工有螺旋槽结构。焊接中，焊具的旋转速度为3500-50000r/min，焊接速度为5-2000mm/min，焊具轴线方向与被焊母材表面法线方向的夹角为0-3°。本发明解决了当前高转速搅拌摩擦焊工艺所面临的焊接载荷大、焊接成本高、焊接效率低、可适用范围窄等问题

Bu2SnO催化反应耦合法清洁合成苯氨基甲酸甲酯

加压条件下,对反应耦合法清洁合成苯氨基甲酸甲酯（MPC）的催化剂进行了筛选,对反应工艺优化、催化剂的循环使用和表征等方面进行了研究。在筛选的催化剂中,Bu2SnO是较为理想的催化剂。在反应物碳酸二甲酯（DMC）和二苯基脲（DPU）的摩尔比为10∶1,催化剂Bu2SnO的用量为2%,160℃时,反应2h,MPC的收率达到98%,远高于文献结果（77%）。催化剂Bu2SnO循环使用4次后,催化活性基本不变。对反应前后的Bu2SnO进行了FTIR、XPS和XRD表征,结果表明,反应后从釜液中用水作沉淀剂絮凝沉淀出的催化剂绝大部分仍为Bu2SnO,并可能含有其他微量未水解的催化剂中间体