0 IntroductionAt present,photoelastic technology is widely used to measure the stress and thestress distribution of machinery parts models.In order to measure the stress and stressdistribtuion of machinery parts on the spot,we have to apply interference priciple ofreflective polarized light.What the interference principle of reflective polarized light is:stick proper isotropism transparent,the same thickness membrane on the
Nitrided- iron nanometer powder is prepared by thermal chemical vapor- phase reaction method,using Fe Cl2 · n H2 O and NH3 as starting material.The physical properties of the powder is measured by means of XRD,XPS,TEM,VSM etc,and physical phase shape, size and magneticpropertiesof the powderis also characterized.Experimentresults show ni- trided- iron ultrafine powder of uniform,high pure,chain- of- spherical and high magnetics can be prepared by improving synthesis reaction instrument.The physical property index of the powder prepared in this instrumentis preferable to Tanaka′s same study results.