An effective catalyst carrier SiO_(2):Enhancing catalytic and combustion properties of CuFe_(2)O_(4)on energetic components

To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.

Discrimination of Chuanminshen violaceum Sheh et Shen from different regions based on fatty acid profiles of roots and leaves

Objectives:The purpose of this paper was to construct a reliable methodology to discriminate the geographical origins of Chuanminshen violaceum Sheh et Shan planted in different regions in Sichuan,China.Materials and methods:Fatty acid profiles of roots and leaves of C.violaceum planted in various regions of Sichuan Province in China,namely Guangyuan(GY),Langzhong(LZ),Jintang(JT),Bazhong(BZ),and Shuangling(SL),were determined using GC-MS followed by multivariate statistical analyses,including orthogonal partial least-squares discriminant analysis and hierarchical clustering analysis.Results:Leaves of C.violaceum showed the highest contents of hexadecatrienoic acid(3.21 g/kg),linoleic acid(6.62 g/kg),andα-linolenic acid(7.24 g/kg),which were all higher than those contained in roots.Chuanminshen violaceum samples collected from LZ,JT,and GY could be clearly distinguished based on fatty acid profiles of leaves and those collected from LZ,GY,and BZ could be clearly distinguished based on fatty acid profiles of roots.Conclusions:Chemometric method is used as a potential approach for analyses of fatty acid profiles of roots and leaves to control the quality of C.violaceum and their powered products.