Identification of twist-angle-dependent excitons in WS2/WSe2 heterobilayersOA

Stacking atomically thin films enables artificial construction of van der Waals heterostructures with exotic functionalities such as superconductivity, the quantum Hall effect, and engineered light-matter interactions.In particular, heterobilayers composed of monolayer transition metal dichalcogenides have attracted significant interest due to their controllable interlayer coupling and trapped valley excitons in moiré superlattices. However, the identification of twist-angle-modulated optical tr...     

Running-induced patellofemoral pain fluctuates with changes in patella water content

Abstract

Although increased bone water content resulting from repetitive patellofemoral joint loading has been suggested to be a possible mechanism underlying patellofemoral pain (PFP), there is little data to support this mechanism. The purpose of the current study was to determine whether running results in increases in patella water content and pain and whether 48 hours of rest reduces patella water content and pain to pre-running levels. Ten female runners with a diagnosis of PFP (mean age 25.1 years) participated. Patella water content was quantified using a chemical-shift-encoded water-fat magnetic resonance imaging (MRI) protocol. The visual analog scale (VAS) was used to quantify subjects' pain levels. MRI and pain data were obtained prior to running, immediately following a 40-minute running session, and 48 hours post-running. Pain and patella water content were compared among the 3 time points using one-way ANOVA's with repeated measures. Immediately post-running, persons with PFP reported significant increases in pain and exhibited elevated patella water content. Pain and patella water content decreased to pre-running levels following 48 hours of rest. Our findings suggest that transient changes in patella water content associated with running may, in part, contribute to patellofemoral symptoms.     

关于电矢量和磁矢量的讨论

本文通过对电场强度、电位移、磁感应强度、磁场强度的讨论得知电场强度和电位移不仅与自由电荷有关,而且与极化电荷有关;磁感应强度和磁场强度不仅与传导电流有关,而且与磁化电流有关.     

可控随机非完整Hamilton系统的矩稳定

研究了可控随机非完整Hamilton系统的矩稳定性的条件，通过恰当地选择控制参量u，从而使系统满足稳定性条件，首先，给出可控随机非完整Hamilton系统的运动方程和平衡方程，然后，讨论了可控随机非完整Hamilton系统的均值稳定性的条件。     

稀磁半导体CdS:CO~(2+)光学吸收谱的理论计算

通过对过渡族自由离子ＣＯ２＋光谱的实验值进行半经验的拟合，得到了它的３ｄ电子波函数，并利用晶体场理论，计算了 ＣｄＳ： ＣＯ２＋的光学吸收谱， 计算结果与实验值吻合很好。     

磁性液体密封机理的研究

根据悬浮液的分散团聚理论,提出了磁流变效应的机理,并推导出磁流变液屈服应力公式。根据磁流变流体的磁流变效应,推导出了磁性液体密封压力的计算公式,磁性液体的密封压力与磁性液体的屈服应力、密封结构的长度和间隙相关。采用狭缝式磁流变液流变性能测试系统,测试了现有磁性液体的屈服应力,对已有的磁流体密封装置进行了实验研究,该公式计算结果与实验结果吻合。     

从变质量物体的运动谈起

牛顿运动定律以及由牛顿第二定律推导出的动量定理、动量矩定理、动能定理,只适用于宏观低速的情况下,而且在运动的过程中,物体的质量是恒定不变的。然而在宏观低速的情况下,我们会遇到许多变质量物体运动的问题,在此情况下,牛顿运动定律以及由此推导出的三条基本定理将要做一定的修改,其表达式是不一样的。     

发展战略性新兴产业的研究与思考——以安徽省马鞍山磁性材料产业发展为例

近年来,发展战略性新兴产业方兴未艾,如何结合各地实际培育和发展战略性新兴产业,地方政府进行了一系列的探索和实践.本文深入剖析了安徽省马鞍山市磁性材料产业发展现状及发展瓶颈,提出了马鞍山市磁性材料产业发展要准确定位、拓宽融资渠道、促进自主创新、优化产业发展环境等对策,并认为各地发展战略性新兴产业要注重培育和改造提升两手抓、以创新驱动发展、加强产业载体建设、不断优化产业发展环境.     

1-甲氧基环己硅烷类液晶物的理论研究

运用AM1和PM3两种SCF-MO方法,通过能量梯度全优化计算,给出5种1-甲氧基环己硅烷类液晶化合物(联苯基乙烷类系列)的稳定几何构型、电子结构和生成热、偶极矩、前沿轨道能级等性质,并结合有机电子理论进行了分析和讨论。     

磁场对单电子量子双环基态能量E_((0,0))的影响

给出了单电子量子同心环基态能量E(0,0)随磁场和势垒的变化规律,并对变化规律进行分析.结果表明,单电子量子同心环基态能量随磁场增大而增大,由于磁场的存在,原来的基态能级分裂成三个能级.由于量子同心环中势垒的存在,使得单电子量子同心环基态能量增大,基态能量随势垒的增大而增大.