Spatiotemporal mapping of microscopic strains and defects to reveal Li-dendrite-induced failure in all-solid-state batteries

Solid-state electrolytes (SSEs) are key to the success and reliability of all-solid-state lithium batteries, potentially enabling improvements in terms of safety and energy density over state-of-the-art lithium-ion batteries. However, there are several critical challenges to their implementation, including the interfacial instability stemming from the dynamic interaction of as-formed dendritic lithium during cycling. For this work, we emphasize the importance of studying the spatial distribution and temporal evolution of strains and defects in crystalline solid-state electrolytes at the micro-scale, and how this affects dendrite growth. A proof-of-principle study is demonstrated using the synchrotron radiation based micro Laue X-ray diffraction method, and a custom-developed in-situ cycling device. Defects and residual strains are mapped, and the evolution of intragranular misorientation is observed. The feasibility of using this technique is discussed, and recommendations for micro-strain engineering to address the Li/SSEs interfacial issues are given. Also, work directions are pointed out with the consideration of combining multi-techniques for “poly-therapy”.     

Urinary mercury in people living near point sources of mercury emissions

As part of the European Mercury Emissions from Chlor Alkali Plants (EMECAP) project, we tested the hypothesis that contamination of ambient air with mercury around chlor alkali plants using mercury cells would increase the internal dose of mercury in people living close to the plants. Mercury in urine (U-Hg) was determined in 225 individuals living near a Swedish or an Italian chlor alkali plant, and in 256 age- and sex-matched individuals from two reference areas. Other factors possibly affecting mercury exposure were examined. Emissions and concentrations of total gaseous mercury (TGM) around the plants were measured and modeled. No increase in U-Hg could be demonstrated in the populations living close to the plants. This was the case also when the comparison was restricted to subjects with no dental amalgam and low fish consumption. The emissions of mercury to air doubled the background level, but contributed only about 2 ng/m(3) to long-term averages in the residential areas. The median U-Hg levels in subjects with dental amalgam were 1.2 microg/g creatinine (micro/gC) in Italy and 0.6 microg/gC in Sweden. In individuals without dental amalgam, the medians were 0.9 microg/gC and 0.2 microg/gC, respectively. The number of amalgam fillings, as well as chewing, fish consumption, and female sex were associated with higher U-Hg. The difference between the countries is probably due to higher fish consumption in Italy, demethylated methyl mercury (MeHg) being partly excreted in urine. Post hoc power calculations showed that if the background mercury exposure is low it may be possible to demonstrate an increase in U-Hg of as little as about 10 ng/m(3) as a contribution to ambient mercury from a point source.     

基于0.35μm CMOS工艺的APD器件仿真分析

提出了一种基于0.35μm CMOS工艺的、具有p+/n阱二极管结构的雪崩光电二极管(APD),器件引入了p阱保护环结构.采用silvaco软件对CMOS-APD器件的关键性能指标进行了仿真分析.仿真结果表明:p阱保护环的应用,明显降低了击穿电压下pn结边缘电场强度,避免了器件的提前击穿.CMOS APD器件的击穿电压为9.2V,工作电压下响应率为0.65 A/W,最大内部量子效率达到90％以上,响应速度能够达到6.3 GHz,在400～900 nm波长范围内,能够得到很大的响应度.     

REPLY TO VAN ROOTSELAAR'S CRITICISMS OF MY THEORY OF THINGS

Van Rootselaar criticizes some points in my theory of things for being allegedly trivial, others for being mistaken. While some results are indeed mathematically trivial they are not so philosophically. As for the mistakes, some arc undoubtedly there, most can be corrected easily, and others require changes that have been introduced in the final version of the theory. The rest arc not mistakes but misunderstandings, perhaps unavoidable given the brevity of the original paper.     

磁钢感应加热的不稳定性

磁钢的居里等温面,是钢加热时从铁磁性状态向顺磁性状态转变、冷却时则反之的第二级相变面。磁钢感应加热时,居里等温面磁导率的急剧变化及其空间位置的改变将导致感应电流密度和释热源的空间再分布,在一定条件下,这将引起居里相变面不稳定,会随着时间和空间产生波动,断开成独立的区段。     

Orthogonal ligation to spherical polymeric microparticles: Modular approaches for surface tailoring

Modular ligation strategies for the functionalization of polymeric microspheres provide new perspectives for their applications in material science. In the current trend article we highlight variable synthetic procedures for generating functional microspheres via orthogonal modular conjugation chemistries. An overview of the different surface chemistries available is provided, followed by surface-sensitive characterization techniques relevant for the microparticles. Finally, we explore future trends in modular orthogonal modification approaches on microparticles and provide an outlook on the perspectives that the field of surface-modification of polymeric microparticles holds.     

基于谓词逻辑的原型系统生成方法研究

本文采用面向对象思想和模型驱动技术,提出一种基于谓词逻辑的原型系统生成方法.该方法以模型为基本元素,通过对静态模型和动态模型信息实施约束抽取和迭代精化等操作生成原型系统.在生成过程中遵循信息对等原则,并引入谓词逻辑使转换过程建立在牢固的数学基础之上,更能够保证原型系统的正确性和完整性,更易于处理需求变化对系统造成的影响...     

ZnO压敏防雷芯片工频耐受与通流能力的相关性

为了研究ZnO压敏防雷芯片的工频过电压耐受特性和8/20μs通流能力的相关性,在生产线上抽取同批次产品进行工频过电压耐受试验和8/20μs通流能力试验。研究结果表明:工频过电压老化后会使压敏电阻的通流能力下降,但经过8/20μs雷电流峰值20 kA冲击后,压敏电阻的工频过电压耐受能力会增强,在冲击15次左右时达到最大值,随着冲击次数的增多,工频过电压耐受能力会降低。     

基于μC/OS-Ⅱ和LwIP的嵌入式Web服务器实现

采用以ARM Codex-M3为内核的32位微控制器LPC1768,利用其内置以太网控制器搭建web服务器.web服务器以μC/OS-Ⅱ为操作系统,并在其基础上,成功移植了LwIP协议栈,通过该协议栈,实现了HTTP(超文本传输协议)服务.文中介绍了该系统的硬件设计和软件开发过程,涉及μC/OS-Ⅱ的移植、LwIP协议...     

高功率窄线宽2.1 μm光学参量振荡器

报道了一种基于氧化镁掺杂的周期性极化铌酸锂的高功率、窄线宽的2.1μm近简并单谐振光学参量振荡器.该光学参量振荡器使用一台自行搭建的近基模调Q线偏振Nd:YAG激光器作为抽运源,抽运光经过聚焦后二次抽运四镜驻波腔结构的周期性极化铌酸锂光学参量振荡器,实现了稳定的高功率和高光束质量2.1μm激光输出.利用体光栅作为输出镜,在重复频率为10 k Hz时,产生的2.1μm激光线宽小于2 nm,最高功率为8.4 W,水平方向和竖直方向的光束质量因子M2分别为3.8和4.1.