Transient Thermo-Mechanical Analysis of Functionally Graded Hollow Circular Cylinders

Thermo-mechanical analysis of functionally graded hollow circular cylinders subjected to axisymmetric mechanical and transient thermal loads is carried out in this study. Thermo-mechanical properties of functionally graded materials (FGM) are assumed to be temperature independent and vary continuously in the radial direction of the cylinder. Employing the Laplace transform, the Galerkin method and series method for ordinary differential equations, solutions for the time-dependent temperature and transient thermo-mechanical stresses are obtained. As an example, a molybdenum/mullite FGM with material properties obeying the exponential law is considered. Effects of heat transfer coefficients and gradient parameters of FGM on the time-dependent temperature and transient thermal stresses are discussed in detail.     

基于TABLEAU的居民电量可视化监测

现阶段,国家电网公司大力推行营配贯通,打造地理信息系统。该系统目前仍存在查询电量信息慢、无法监测大电量用户等问题。提出的模型以营配贯通的思想为立足点,基于国家电网公司推广使用的数据分析软件Tableau,以业务营销系统与GIS系统为数据来源,运用函数将用电量信息与地图相结合,搭建可视化交互界面。解决了GIS系统目前存在的查询用电信息难的问题,不仅为工作人员的日常工作提供了数据上的支持,且做到了对大电量用户的监测报警。     

深井软岩大变形巷道全断面卸压支护技术

针对深井软岩巷道长期大变形的特点,提出以"顶帮高预紧力让压锚索+底板卸压槽"为基础的深部软岩巷道全断面卸压支护技术,保证支护结构在提供高强度支护阻力的同时,能够适应围岩变形,避免被过早破坏。以车集矿28采区轨道巷支护工程为例,采用全断面卸压支护技术最终控制了围岩变形,维护了巷道稳定性。     

考虑实时SOC与动态循环效率的电池损耗评估及储能定容策略

笔者提出一种高精度电池寿命损耗评估模型,该模型能充分挖掘厂家提供数据中的有效信息,从而建立起动态循环效率、放电深度（DOD）与实时荷电状态（SOC）应力等因素之间的映射关系。同时,针对采用更精细化的储能模型所引入的非线性项,提出一种基于滚动McCormick松弛方法的优化求解算法,该算法可将原本包含混合整数非线性规划问题转化为混合整数线性规划问题,从而实现优化问题的数值化求解。最后,通过算例证明所提出的精细化电池寿命模型与滚动McCormick求解算法的合理性和优越性。     

Interlayer Engineering of Molybdenum Trioxide toward High‐Capacity and Stable Sodium Ion Half/Full Batteries

Orthorhombic molybdenum trioxide (MoO₃) is one of the most promising anode materials for sodium‐ion batteries because of its rich chemistry associated with multiple valence states and intriguing layered structure. However, MoO₃ still suffers from the low rate capability and poor cycle induced by pulverization during de/sodiation. An ingenious two‐step synthesis strategy to fine tune the layer structure of MoO₃ targeting stable and fast sodium ionic diffusion channels is reported here. By integrating partially reduction and organic molecule intercalation methodologies, the interlayer spacing of MoO₃ is remarkably enlarged to 10.40 Å and the layer structural integration are reinforced by dimercapto groups of bismuththiol molecules. Comprehensive characterizations and density functional theory calculations prove that the intercalated bismuththiol (DMcT) molecules substantially enhanced electronic conductivity and effectively shield the electrostatic interaction between Na⁺ and the MoO₃ host by conjugated double bond, resulting in improved Na⁺ insertion/extraction kinetics. Benefiting from these features, the newly devised layered MoO₃ electrode achieves excellent long‐term cycling stability and outstanding rate performance. These achievements are of vital significance for the preparation of sodium‐ion battery anode materials with high‐rate capability and long cycling life using intercalation chemistry.     

剁辣椒家常加工对5种农药残留的影响

为研究剁辣椒家常加工过程对农药残留的影响,在实验室模拟沉积农药条件下,通过优化分散固相萃取方法建立了剁辣椒中5种农药的QuEChERS结合液相色谱-串联质谱检测方法,研究了经水洗、晾干、切碎、加盐腌制4道家常加工工序后,吡虫啉、啶虫脒、精甲霜灵、嘧菌酯和苯醚甲环唑5种农药在剁辣椒加工过程中的残留量变化情况。结果表明:剁辣椒中5种农药的残留量随着加工工序的增加而呈下降的趋势,全过程加工因子分别为0.2、0.32、0.23、0.21和0.14。经过剁辣椒家常腌制21 d后5种农药的农药残留的膳食暴露量大大降低,膳食风险指数分别较未加工降低了80.6%、68.7%、76.3%、78.4%、85.9%。而在不同加工工序中不同农药的加工因子变化有差异,这与农药本身的理化特性密不可分,log Kow（辛醇水分配系数）值小的农药（吡虫啉和啶虫脒）,在水洗处理下的残留量少,且冲洗处理较浸泡处理去除农药效果好;而log Kow值大的农药（嘧菌酯和苯醚甲环唑）,在加盐腌制处理下的残留量少,且在剁辣椒腌制的无氧环境中农药降解速率逐渐变缓。因此剁辣椒家常加工过程可以减少农药残留量,提高剁辣椒食用安全性。     

Strained n-Channel Transistors With Silicon Source and Drain Regions and Embedded Silicon/Germanium as Strain-Transfer Structure

We report the demonstration of 55 nm gate length strained n-channel field-effect transistors (n-FETs) having an embedded Si_1-xGe_x structure that is beneath the Si channel region and which acts as a strain-transfer structure (STS). The Si_1-xGe_x STS has lattice interactions with both the silicon source and drain regions and with the overlying Si channel region. This effectively results in a transfer of lateral tensile strain to the Si channel region for electron mobility enhancement. The mechanism of strain transfer is explained. Significant drive current I_on enhancement of 18% at a fixed off-state leakage I_off of 100 nA/mum is achieved, which is attributed to the strain-induced mobility enhancement. Furthermore, continuous downsizing of transistors leads to higher I_on enhancement in the strained n-FETs, which is consistent with the increasing transconductance G_m improvement when the gate length is reduced.     

二通插装溢流阀中节流孔的功能分析

结合二通插装溢流阀的结构原理,对节流孔在溢流阀控制级中的功能进行分类分析,并通过实例对节流孔在实际使用中的功能作了介绍。