FeSi2Ti相重构对工业硅中杂质酸洗行为的影响

为了强化酸洗提纯多晶硅技术,本工作通过FeSi2Ti相重构来提高酸洗的除杂能力。研究结果发现,经Si-Fe-Ti合金精炼之后,工业硅中的主要杂质相由原来的Si-Fe-Al、Si-Al-Fe和Si-Ti-Fe相转变成FeSi2Ti、Si-Ti-F...陕西省“无机高纯硅材料产业创新链”科技项目(2017TSCXL-GY-06-02)~

3D-printed integrative probeheads for magnetic resonance

射频探头前端作为核磁共振设备的核心部件之一，极大程度的决定着系统实验性能的优劣。探头前端通常由射频线圈、射频电路及样品检测管道等部分组成。现有的射频线圈制作技术主要是通过手工或机械手段按照所需的线圈形状进行绕制。但是，当线圈结构较为复杂、不规则，或体积尺寸较小时，常规绕制方法便难以满足结构设计和制造的精度需求，因此造成线圈性能的劣化，增大检测区域的射频场不均匀性，对核磁共振检测产生负面影响。本研究中，利用3D打印熔融沉积制造或光敏树脂选择性固化技术精确加工出一体化磁共振探头前端，使用常温液态金属填充线圈模型管路形成射频线圈，搭建出稳定的一体化磁共振射频探头。利用高精度3D打印和液态金属灌注技术制备出包含有射频线圈和定制化样品管道结构在内的一体化磁共振射频探头前端，克服了传统磁共振三维微型线圈成型困难、与样品腔匹配程度差等问题，提高了探头的信噪比，为定制化的磁共振检测提供了新思路。 该工作由厦门大学电子科学与技术学院陈忠教授、游学秋副研究员和孙惠军高级工程师共同指导完成，博士研究生谢君尧为论文第一作者。厦门大学电子科学与技术学院黄玉清高级工程师、王忻昌副教授、倪祖荣助理教授、硕士研究生张德超，化学化工学院杨朝勇教授、博士研究生李星锐，萨本栋微米纳米科学技术研究院陈宏教授为合作作者。【Abstract】Magnetic resonance (MR) technology has been widely employed in scientific research, clinical diagnosis and geological survey. However, the fabrication of MR radio frequency probeheads still face difficulties in integration, customization and miniaturization. Here, we utilized 3D printing and liquid metal filling techniques to fabricate integrative radio frequency probeheads for MR experiments. The 3D-printed probehead with micrometer precision generally consists of liquid metal coils, customized sample chambers and radio frequency circuit interfaces. We screened different 3D printing materials and optimized the liquid metals by incorporating metal microparticles. The 3D-printed probeheads are capable of performing both routine and nonconventional MR experiments, including in situ electrochemical analysis, in situ reaction monitoring with continues-flow paramagnetic particles and ions separation, and small-sample MR imaging. Due to the flexibility and accuracy of 3D printing techniques, we can accurately obtain complicated coil geometries at the micrometer scale, shortening the fabrication timescale and extending the application scenarios.The work is supported by the National Natural Science Foundation of China (Grants U1632274, 11761141010, U1805261, 11475142, 22073078, and 61801411), and China Postdoctoral Science Foundation (2017M622075).研究工作得到国家自然科学基金、中国博士后科学基金等项目支持

基于小波分解的同步带传动噪声特性研究

同步带传动噪声可以分为啮合冲击噪声、横向振动噪声、空气流动噪声和摩擦噪声，每种噪声所处的具体频段不同。为了研究汽车同步带噪声信号的频率分布特性，首先，理论分析了同步带传动各种噪声的频域分布情况；然后，针对ZA型汽车同步带进行变转速变张紧力试验；最后，基于小波分解的分析方法，得出同步带传动噪声信号的频段分布特性。结果表明，随着转速的增加，啮合冲击噪声增加，同步带传动噪声源中啮合冲击噪声能量比重增加，啮合冲击噪声主要集中在高频段，横向振动噪声主要集中在低频段。研究为汽车发动机的减振降噪提供了依据

转速对多楔带三轮传动系统噪声的影响规律研究

为了研究转速对多楔带三轮传动系统噪声大小的影响规律，以6PK多楔带为例，基于声阵列原理搭建了多楔带三轮传动系统噪声测试试验装置，得到了不同转速下三轮传动系统中声压的时域信号和噪声声压分布云图。随着转速的增加，多楔带三轮传动系统中的噪声大小逐渐增加。多楔带横向振动引起的低频噪声随着转速的增加逐渐增大，通过多普勒激光测振仪测量得出多楔带横向振动噪声的增加是由于多楔带横向振动幅值的增大引起的；通过噪声声压云图可以看出，多楔带与带轮之间摩擦引起的高频摩擦噪声大小随着转速的增加而增大；当多楔带三轮传动系统发生共振时，传动系统的噪声明显增加

Nursing experience of dressing change at home for a patient with heart failure complicated with pressure injuries (1例心力衰竭合并压力性损伤患者居家换药心得体会)

This paper summarized the nursing experience of dressing change at home for a patient with heart failure complicated with pressure injuries. The nursing strategy included professional wound evaluation, dressing change, position management, health education, nutrition support, and blood sugar control through the management of lifestyle and diet, creating a good condition for wound healing. (本文总结1例心力衰竭合并压力性损伤患者的居家换药体会。通过规范的伤口评估与换药处理、患者体位管理、健康宣教、营养支持以及从生活习惯和饮食结构等方面进行血糖控制, 为创面愈合创造良好的条件。

Nursing experience of dressing change at home for a patient with heart failure complicated with pressure injuries (1例心力衰竭合并压力性损伤患者居家换药心得体会)

This paper summarized the nursing experience of dressing change at home for a patient with heart failure complicated with pressure injuries. The nursing strategy included professional wound evaluation, dressing change, position management, health education, nutrition support, and blood sugar control through the management of lifestyle and diet, creating a good condition for wound healing. (本文总结1例心力衰竭合并压力性损伤患者的居家换药体会。通过规范的伤口评估与换药处理、患者体位管理、健康宣教、营养支持以及从生活习惯和饮食结构等方面进行血糖控制, 为创面愈合创造良好的条件。