体外产气法评定膨化微贮玉米秸秆的营养价值

试验旨在对膨化微贮、黄贮、常规玉米秸秆的体外降解参数进行测定,对膨化微贮、黄贮、常规玉米秸秆的营养价值进行评定。选用三头装有永久性瘤胃瘘管的草原红牛作为瘤胃液的供体,采用体外产气法测定膨化微贮、黄贮、常规玉米秸秆体外培养24 h的产气量(GP)、发酵液的pH、氨态氮浓度(NH3-N)、微生物蛋白浓度(MCP)及挥发性脂肪酸含量(VFA)。结果表明:三种玉米秸秆体外发酵的pH、氨态氮浓度、挥发性脂肪酸的含量没有显著差异(P>0.05),但膨化微贮玉米秸秆的产气量>黄贮玉米秸秆>常规玉米秸秆(P<0.05),膨化微贮玉米秸秆的24 h体外发酵的微生物蛋白浓度显著高于常规玉米秸秆(P<0.05),膨化微贮玉米秸秆的乙酸/丙酸显著高于常规玉米秸秆(P<0.05)。试验结果表明,膨化微贮玉米秸秆的营养价值大于黄贮玉米秸秆,黄贮玉米秸秆大于常规玉米秸秆。

美国输出“娱乐化”文化产品的审视与思考

扩张主义一直是美国核心文化的重要组成部分。对外文化扩张则作为美国实践对外扩张主义的主要切入口,成为美国对外进行价值观传播的主要战略手段。通过对外输出"娱乐化"文化产品,美国在推销美国式民主、争取民意人心方面收获巨大。面对美国的文化扩张,我们要理性地对待,并努力从加强自身文化建设入手来抵制西方价值观的侵蚀。媒体工作者要肩负起时代赋予的责任,对内重视维护和弘扬我国的优秀本土文化,对外主打"文化牌",巧用"娱乐化"文化产品,积极传播我国的优秀文化和文明。

Parametric study of thermo-hydro-mechanical response of claystone with consideration of steel corrosion

In this paper,the thermo-hydro-mechanical(THM)response of claystone is studied via a series of parametric studies,considering the evolution of mechanical properties and deformation behavior of corroded steel.The numerical simulations are performed by using a coupled THM finite element code and two different constitutive models:a visco-elastoplastic model for geological formation and a von Mises type model for steel liner.The mechanical properties and deformation behavior of corroded steel are described in a conceptual model.Finally,a disposal tunnel supported by a steel liner is studied and a series of parametric studies is defined to demonstrate the corrosion effects of steel liner on the THM response of the claystone.The comparison of different numerical calculations exhibits that the volumetric expansion related to corrosion products has an important impact on the stress and displacement fields in the claystone surrounding the disposal tunnel.However,the evolutions of temperature and liquid pressure in the claystone are essentially controlled by its THM properties and independent of the steel corrosion.

膨化微贮玉米秸秆对肉牛生产性能及血液生化指标的影响

选用体质量相近的(354.83±16.11)kg西门塔尔杂交母牛18头,随机分为3组,每组6头。3组试验动物饲粮的精料相同,粗料比为膨化微贮、黄贮、干玉米秸秆。结果表明:(1)膨化微贮玉米秸秆组的日增重显著大于黄贮、干玉米秸秆组(P<0.05),且黄贮与干玉米秸秆组之间无显著性差异(P>0.05)。膨化微贮玉米秸秆组的干物质采食量极显著大于黄贮组,黄贮组极显著大于干玉米秸秆组(P<0.01)。(2)各组肉牛血清中总蛋白(TP)、球蛋白(GLB)、葡萄糖(GLU)、谷丙转氨酶(ALT)、总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、丙二醛(MDA)含量无显著性差异(P>0.05)。膨化微贮玉米秸秆组的白蛋白(ALB)含量显著高于干玉米秸秆组(P<0.05),黄贮和膨化微贮玉米秸秆组的谷草转氨酶(AST)含量极显著高于干玉米秸秆组(P<0.01)。结果表明,膨化微贮玉米秸秆组肉牛的生产性能高于黄贮和干玉米秸秆组,且对血液中大多数的生理指标无显著影响。