AR箭图一类连通分支的结构

给出了代数闭域上基连通有限维代数A的AR箭图中带有方向圈及不含有DT_r周期模且除投射-内射模外所含元均是左稳定模的一类连通分支的结构。     

Carbon Nitride Nanowire Bundle and Tubes：Solid-state Synthesis,Characterization and Photoluminescent Properties

Graphite-like carbon nitride nanowire bundles were synthesized from melamine via the solid state thermolysis at relatively low temperature(400 °C).Hexagonal carbon nitride tubes were prepared for the first time by heating the nanowire bundles at 550 °C in argon atmosphere.The forming process of tubes and transformation of the molecular structures from s-triazine rings to tri-s-triazine units were analyzed.The blue and yellow-green emission photoluminescent(PL) properties of the products were investigated in...     

科普展上的法国展品

 今年八月上旬在军事博物馆举办的科普展会上,来自法国的展台尤其受到人们的关注,展台上只是用简单的管子、砂子、玻璃、木板等用具,生动地展现出科学道理,观众通过简单的互动便可了解到如摩擦、压力、振动等知识。这给中国观众带来了耳目一新的感受,也给动辄用大展览大制作的国内展商们以很好的启发。