Deriving phosphorus atomic chains from few-layer black phosphorus

Phosphorus atomic chains,the narrowest nanostructures of black phosphorus (BP),are highly relevant to the in-depth development of BP-based one-dimensional (1D) nano-electronics components.In this study,we report a top-down route for the preparation of phosphorus atomic chains via electron beam sculpturing inside a transmission electron microscope (TEM).The growth and dynamics (i.e.,rupture and edge migration) of 1D phosphorus chains are experimentally captured for the first time.Furthermore,the dynamic behavior and associated energetics of the as-formed phosphorus chains are further investigated by density functional theory (DFT) calculations.It is hoped that these 1D BP structures will serve as a novel platform and inspire further exploration of the versatile properties of BP.     

Composition and Interface Engineering of Alloyed MoS2xSe2(1–x) Nanotubes for Enhanced Hydrogen Evolution Reaction Activity

Hierarchical MoS_2xSe_2(1?x) nanotubes assembled from several‐layered nanosheets featuring tunable chalcogen compositions, expanded interlayer spacing and carbon modification, are synthesized for enhanced electrocatalytic hydrogen evolution reaction (HER). The chalcogen compositions of the MoS_2xSe_2(1?x) nanotubes are controllable by adjusting the selenization temperature and duration while the expanded (002) interlayer spacing varies from 0.98 to 0.68 nm. It is found that the MoS_2xSe_2(1?x) (x = 0.54) nanotubes with expanded interlayer spacing of 0.98 nm exhibit the highest electrocatalytic HER activity with a low onset potential of 101 mV and a Tafel slope of 55 mV dec^?1. The improved electrocatalytic performance is attributed to the chalcogen composition tuning and the interlayer distance expansion to achieve benefitting hydrogen adsorption energy. The present work suggests a potential way to design advanced HER electrocatalysts through modulating their compositions and interlayer distances.     

可编程控制器在大型球磨机上的应用

可编程控制器在大型球磨机上的应用，对陶瓷工业设备的现代化有着十分重要的意义。利用可编程控制器不但可以控制球磨机的运行，而且还可以对大型球磨机在线监测或定期监测，因此，带有可编程控制器的大型球磨机功能齐全，运行可靠。     

国外高放废物地质处置库地下实验室环境监测与影响评价浅析

系统分析芬兰ONKALO地下实验室环境监测要素和因子,梳理美国尤卡山高放废物处置库环境影响评价工作内容,与我国拟建地下实验室进行对比分析,为我国相关研究及后续处置库环境影响评价提出工作建议。     

IBIS模型的仿真研究与应用分析

光收发一体模块作为光通信的核心器件一直是光通信领域的研究热点.通过阐述IBIS模型与PCB板信号完整性之间的关系,介绍了基于IBIS模型的信号完整性分析的概念及仿真步骤,最后给出了基于IBIS模型的仿真分析在千兆SFP光纤收发器中的成功应用实例.     

青铜文物腐蚀过程的模拟研究

采用地球化学模式程序EQ3/6,研究了青铜器蚀变过程.模拟结果表明,在土壤中常见的Eh和pH及研究区的年平均温度条件下,溶液中铜离子的含量达到一定的浓度时,可以生成赤铜矿(当Cu≈0.0016 mol/L)、孔雀石及黑铜矿(当Cu≈0.0079mol/L)等次生矿物,溶液中Cu的存在形式也发生了变化,即CuCO3(aq)所占的比例不断减小,而Cu2 和CuOH 的含量则相继增高,且Cu2 的增幅大于CuOH .青铜制品中的Cu在不同的Eh和pH条件下腐蚀的产物是不同的.在研究的Eh(-0.2 V～0.7 V)和pH值(5～9.5)范围内,赤铜矿的形成不受氧化-还原电位及酸碱度变化的影响;孔雀石和黑铜矿形成于较高pH值(＞7)和较高的氧化-还原电位(＞0.2 V)条件;而辉铜矿则形成于较低的pH值(＜7)和较低的Eh(＜0.2 V)条件.水-青铜器相互作用的模拟研究结果表明,在作用过程中将依次生成赤铜矿、孔雀石、黑铜矿、白铅矿、锡石及在合金内层残留的自然Cu、Pb和Zn.在这一过程中溶液中Cu和Pb的含量逐渐降低,但Zn的行为则与Cu、Pb相反,即随着合金的溶解在溶液中的含量增加了.在上述模拟结果基础上,建立了青铜器腐蚀的化学作用过程,即青铜器的腐蚀大致可分为两个阶段:第一阶段生成黑铜矿和孔雀石,第二阶段生成白铅矿和锡石等矿物.上述模拟研究结果与现有的测定结果相吻合,同时还揭示了现有的常规研究所不能揭示的腐蚀过程,由此说明不仅可以应用地球化学模式程序来研究青铜器的腐蚀产物,还可以揭示青铜类文物的腐蚀过程及机理.