存在空气阻力情况下的平抛运动轨迹研究

研究了在空气阻力f=-kv情况下,平抛运动水平和竖直方向的运动规律.同时,还用Matlab软件,对此过程进行了模拟,与数学推导的结论相互呼应.     

多枝状γ -MnOOH的低温水热合成与表征

γ-MnOOH multipods were synthesized by a low temperature hydrothermal method. The synthetic procedure is based on the use of PEG200 to reduce KMnO₄ upon controlling the volume of PEG200. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) were used to characterize the products. All pods of them are single crystals, the diameter of each pod is about 40～120 nm and the length is about 800～2 400 nm. A possible formation mechanism was proposed that the intermediate products with a lamellar morphology curled into γ-MnOOH nanorods during the reaction process at first, and then γ-MnOOH multipods formed for the multi-nuclei growth on the tips of the γ-MnOOH nanorods when they were good crystallization.