Electron tomography: An imaging method for materials deformation dynamics

The combination of in-situ and three-dimensional (3D) in transmission electron microscopy (TEM) is one of the emerging topics of recent advanced electron microscopy research. However, to date, there have been only handful examples of in-situ 3D TEM for material deformation dynamics. In this article, firstly, the authors briefly review technical developments in fast tilt-series dataset acquisition, which is a crucial technique for in-situ electron tomography (ET). Secondly, the authors showcase a recent successful example of in-situ specimen-straining and ET system development and its applications to the deformation dynamics of crystalline materials. The system is designed and developed to explore, in real-time and at sub-microscopic levels, the internal behavior of polycrystalline materials subjected to external stresses, and not specifically targeted for atomic resolution (although it may be possible). Technical challenges toward the in-situ ET observation of 3D dislocation dynamics are discussed for commercial structural crystalline materials, including some of the early studies on in-situ ET imaging and 3D modeling of dislocation dynamics. A short summary of standing technical issues and a proposed guideline for further development in the 3D imaging method for dislocation dynamics are then discussed.     

Parametric analyses of evapotranspiration landfill covers in humid regions

Natural soils are more durable than almost all man-made materials. Evapotranspiration （ET） covers use vegetated soil layers to store water until it is either evaporated from the soil surface or transpired through vegetation. ETcovers rely on the water storage capacity of soil layer, rather than low permeability materials, to minimize percolation. While the use of ET covers in landfills increased over the last decade, they were mainly used in arid or semi-arid regions. At present, the use of ET covers has not been thoroughly investigated in humid areas. The purpose of this paper is to investigate the use of ETcovers in humid areas where there is an annual precipitation of more than 800 mm. Numerical analyses were carried out to investigate the influences of cover thickness, soil type, vegetation level and distribution of precipitation on performance of ET covers. Performance and applicability of capillary barriers and a new-type cover were analyzed. The results show that percolation decreases with an increasing cover thickness and an increasing vegetation level, but the increasing trend becomes unclear when certain thickness or LAI （leaf area index） is reached. Cover soil with a large capability of water storage is recommended to minimize percolation. ET covers are significantly influenced by distribution of precipitation and are more effective in areas where rainy season coincides with hot season. Capillary barriers are more efficient than monolithic covers. The new cover is better than the monolithic cover in performance and the final percolation is only 0.5% of the annual precipitation.     

Influence of Cr3+ on yellowish-green UC emission and energy transfer of Er3+/Cr3+/Yb3+ tri-doped zinc silicate glasses

In this paper, we study the influence of Cr³⁺ on yellowish-green upconversion (UC) emission and the energy transfer (ET) of Er³⁺/Cr³⁺/Yb³⁺ tri-doped in SiO₂–ZnO–Na₂O–La₂O₃ (SZNL) zinc silicate glasses under excitation of the 980 nm laser diode (LD). The influence of Cr³⁺ on enhancing the red UC emission of Er³⁺/Cr³⁺/Yb³⁺ tri-doped in SiO₂–ZnO–Na₂O–La₂O₃ zinc silicate glasses under the excitation of 980nm LD was also investigated. The ET processes between Yb³⁺, Cr^3+, and Er³⁺, together with the combination of Yb³⁺-Cr³⁺-Er³⁺, which led to the green UC emission intensity of Er³⁺/Cr³⁺/Yb³⁺ tri-doped in SiO₂–ZnO–Na₂O–La₂O₃ zinc silicate glasses bands centered at ~546 nm have been significantly enhanced. By increasing the concentration of Cr³⁺ from 0 up to 5 mol.%, we can locate the Commission Internationale de l'éclairage (CIE) 1931 (x; y) chromaticity coordinates for UC emissions of Er³⁺/Cr³⁺/Yb³⁺ tri-doped in the central position of the yellowish-green color region of CIE 1931 chromaticity diagram. Besides, the ET processes between the Yb³⁺, Cr³⁺, and Er³⁺ are also proposed and discussed.     

湿润气候区带膨润土垫ET封顶的性能分析

ET(evapotranspiration,腾发)封顶目前主要用于少雨地区的填埋场,本文考虑1500mm的年降雨量,分析一种加膨润土垫(GCL)的新型土工复合ET封顶在湿润地区的工作性能。建立渗流-腾发耦合模型,计算此新型ET封顶和典型单层土ET封顶的地表径流量、地表蒸发量、植被蒸腾量、最终透水量,对比分析两种ET封顶内的水分运移规律及其工作性能。结果表明:新型ET封顶产生的地表径流总量多于典型单层土ET封顶;新型ET封顶通过膨润土垫的低渗透性使上部土层能够储存更多的水分用于后期腾发,其腾发量大于典型单层土ET封顶,尤其是在降雨高峰期更为明显;在该地区,总厚度1.2m的典型单层土ET封顶并不能有效阻止水分渗透到填埋场中,而新型ET封顶能够满足设计要求。     

南宁夏季室内热舒适与空调能耗分析

以问卷调查和实测数据为基础,采用新有效温度ET*探讨了南宁地区夏季室内热舒适性及其对空调能耗的影响.得到当地居民可接受的室内热舒适温湿度范围;并给出空调能耗与当地热舒适要求的变化关系.该地区在确定室内参数时不必过多关注相对湿度,主要考虑室内温度对人体热舒适性和空调能耗的影响.     

Application of MIKE SHE modelling system to set up a detailed water balance computation

Estimation of total water balance is a substantial issue for watershed modelling in order to simulate the major components of the hydrological cycle to determine the stress of different anthropogenic activities on the available water resources within a catchment. In this context, the fully distributed physically based MIKE SHE modelling system was used to simulate the individual hydrological components of the total water balance for the Paya Indah Wetlands (PIW) watershed in the west of Peninsular Malaysia. Results reveal that the overall water balance is predominantly controlled by climate variables. Application of the model to the PIW watershed provides detailed estimation of the total water balance for a first‐order catchment in which actual evapotranspiration (ET) represents approximately 65 and 58%, while overland flow (OL) to the PIW lake system represents 12.38 and 12.3% of the total rainfall during the calibration and validation periods, respectively. The difference of the inflow and outflow was taken as storage in depth. Overall, the model gives a reasonable output of total error of less than 1% of the total rainfall, which in turn indicates that the interaction among components is satisfactorily sustained.     

基于ET的水资源与水环境综合规划研究（I）-理论

本文总结了水资源规划的六个模式，全面综述了水资源规划发展思路，深入阐述了基于ET的水资源与水环境综合规划理论内涵和五大调控机制，提出了综合规划的四个原则、五大目标、决策思路和技术路线，系统建立起基于ET的区域水资源与水环境综合规划研究框架。     

Impact of the condition of storage of tartaric acid solutions on the production and stability of glyoxylic acid

The production and stability of glyoxylic acid was followed during the storage of tartaric acid solutions under various conditions. The solutions were prepared both with and without ethanol. Quantification of glyoxylic acid and other oxidation products, including hydrogen peroxide and formic acid, were performed using ion exclusion chromatography. Glyoxylic acid was only detected in tartaric acid samples that had been stored outdoors and sunlight was identified as the critical component of outdoor storage that allowed its formation. The hydrogen peroxide and glyoxylic acid generated under these conditions were of limited stability due to their reaction with each other to produce formic acid. The concentration of the glyoxylic acid was greatly increased when ethanol was omitted from the sample matrix. Copper(II) enhanced the stability of glyoxylic acid but slowed its production. The reaction pathway responsible for the sunlight-induced production and subsequent stability of glyoxylic acid is discussed.     

金属表面裂纹涡流检测系统

针对现实生活中由于金属裂纹引发的众多灾难性事故,研究设计了一种结构简单、灵敏度高而且便于携带的金属表面裂纹涡流检测装置.该装置应用涡流探伤的基本原理,采用磁性材料,制作了一种精细的涡流传感器,用于前端提取微弱的裂纹信号;后台应用单片机控制电路,处理提取的滤波、放大、A/D转换等信号,最后由单片机驱动声、光报警,显示裂纹缺陷的相对大小,实现了防患于未然的目的.     

PROFIBUS-DP技术在淮钢棒材生产线中的应用

简述电气系统的配置，着重介绍了SIEMENS公司PROFIBUS－DP总线技术在该生产线中的应用，阐述了主站PLC与从站直流调速系统6RA70，交流调速系统6SE70以及远程ET200M的PROFIBUS－DP网络的构成，就从站的交直流速系统的网络数据结构和参数过程数据以及使用STEP7编程软件对PROFIBUS－DP总线的组态方法等作了说明。