中草药饲料添加剂的作用与开发   总被引：3，自引：0，他引：3  

祝耀德  胡庆平  刘兴隆 《中国兽药杂志》2005,39(10):28-30

中草药饲料添加剂不但能发挥促进动物生长的作用,而且能克服化学添加剂引起的动物产品中药物、激素、微量元素的超标残留.本文简述了中草药饲料添加剂的作用和功效,分析了其研发现状及趋势.  相似文献   

Ultrasonic shear wave velocities of MgSiO3 perovskite at 8 GPa and 800 K and lower mantle composition   总被引：1，自引：0，他引：1  

YD Sinelnikov  G Chen  DR Neuville  MT Vaughan  RC Liebermann 《Science (New York, N.Y.)》1998,281(5377):677-679

Ultrasonic interferometric measurements of the shear elastic properties of MgSiO3 perovskite were conducted on three polycrystalline specimens at conditions up to pressures of 8 gigapascals and temperatures of 800 kelvin. The acoustic measurements produced the pressure (P) and temperature (T) derivatives of the shear modulus (G), namely ( partial differentialG/ partial differentialP)T = 1.8 +/- 0.4 and ( partial differentialG/ partial differentialT)P = -2.9 +/- 0.3 x 10(-2) gigapascals per kelvin. Combining these derivatives with the derivatives that were measured for the bulk modulus and thermal expansion of MgSiO3 perovskite provided data that suggest lower mantle compositions between pyrolite and C1 carbonaceous chondrite and a lower mantle potential temperature of 1500 +/- 200 kelvin.  相似文献