有关动物营养与饲料论文选题怎么写
提高双低菜籽皮对反自动物营养价值的研摘要本研究以双低菜籽皮的中性洗涤纤维(NeutralDetergentFiber,NDF)含量为评定指标。采用混合嵌套设计从干式NaOH法(处理时间分别为d1、d2、3d)、尿素氨化法(处理时间分别为1d0、1d5、ZOd)、碱化一氨化复合处理(处理时间分别为15d、ZOd、25d)筛选出最佳处理组及其处理时间;采用L(3‘)正交设计筛选出最佳配比的纤维素酶、B一葡聚糖酶、木聚糖酶和a一淀粉酶处理组;从而得到最佳化学处理组和最佳复合酶制剂处理组。采用扫描电子显微镜(SacunnigEleetrnoMcriosocpe,SEM)技术分析上述最佳处理组处理的双低菜籽皮的结构;并分别以稻草、未处理双低菜籽皮、经最佳化学组处理的双低菜籽皮、经最佳复合酶制剂组处理的双低菜籽皮为粗料配制不同日粮,研究其对湖北麻城黑山羊的生长性能的影响。试验结果如下:与对照组(未处理组)相比,双低菜籽皮经干式Na0H法、尿素氨化法、碱化-氨化复合法处理后中性洗涤纤维(NDF)含量降低,中性洗涤纤维2h4降解率升高。双低菜籽皮经不同化学方法处理后,中性洗涤纤维(NDF)含量组间差异极显著P(<01),中性洗涤纤维2h4降解率组间差异极显著P(<01);双低菜籽皮经同种方法不同时间处理后,时间对NDF含量及中性洗涤纤维24h降解率的影响是极显著(P<01)。就中性洗涤纤维2h4降解率而言,干式NaOH处理组比对照组的分别提高了22%、16%、58,64%,尿素氨化处理组比对照组的分别提高了81%、()7%、巧64%,碱化一氨化复合处理组比对照组的分别提高了88%、04%、79%。双低菜籽皮经不同配比的复合酶制剂处理后NDF含量组间差异不显著P(>005),中性洗涤纤维2h4降解率组间差异不显著P(>005)。与对照组相比,NDF含量均下降,分别降低了15%、59%、56%、81%、42%、57%、%、62%、05%;中性洗涤纤维24h降解率均有所提高,分别提高了07%、89,05%、75%、42%、29%、77%、72%、96%、74%。扫描电镜观察发现处理前后双低菜籽皮的物理结构变化显著。未处理的双低菜籽皮结构紧密,细胞器清晰可见;经过碱化一氨化复合处理之后,薄壁组织膨胀,形成一些“孔穴”结构,并且大部分的细胞器解体脱落:经过复合酶制剂处理后双低菜籽皮表面光滑,“孔穴”结构更加规则,并且细胞器基本完全解体脱落。表明双低菜籽皮经过处理后细胞壁疏松,为瘤胃液的渗透提供有利的条件,从而提高双低当动物营养价值的研究菜籽皮的利用效率。两种处理方法处理的双低菜籽皮组与稻草组相比,山羊的采食量、日增重、料肉比差异显著(P<005);与未处理的双低菜籽皮组相比,差异不显著P(>005),但山羊的采食量和日增重有所提高,料肉比下降。结果表明,双低菜籽皮经碱化一氨化复合法在常温下处理20d后效果最佳;双低菜籽皮的最佳复合酶制剂的配比为纤维素酶38469、B一葡聚糖酶16679、木聚糖酶20009和a一淀粉酶01259(添加比例为在5009双低菜籽皮中的含量)。碱化一氨化复合处理和复合酶制剂处理能够提高双低菜籽皮的营养价值,并且饲喂经最佳处理组处理的双低菜籽皮可以提高山羊的生长性能。关键词:双低菜籽皮;氨化;复合酶制剂;扫描电镜;瘤胃尼龙袋法目录中文摘要···············,····································,·················,·······································……I英文摘要······················································································,····················,··……1111,前言·······························,··················································································……1开发双低菜籽皮饲料的重要性·················,··············································……2双低菜籽皮的特点和营养价值·······························································……3低质粗饲料的处理方法·····,·,··,······,··················,······································……4低质粗饲料在反当动物饲料利用中存在的问题························,··········……5本试验研究的目的和意义·······································································……材料与方法······································,·······························································……1样品的采集·································,·····························································……2处理双低菜籽皮的化学方法·····,·····························································……3处理双低菜籽皮的酶制剂方法,·········,·············································,······……4双低菜籽皮营养成分瘤胃降解率的测定···············································……5扫描电子显微镜分析···············································································……26山羊饲养试验···························································································……7检测指标···································································································……132,8一计算公式与数据处理·······················································,·····················……‘’结果与分析··,·····,·······,··,,,···,····,,······································································……143,1双低菜籽皮的主要成分含量········,··························································一2化学处理双低菜籽皮的成分分析···············································,···········……3复合酶制剂处理双低菜籽皮的成分分析···············································……4扫描电镜分析处理前后双低菜籽皮结构的变化···································……5不同处理饲粮对山羊生长性能的影响···················································……讨论······,···················,···,·····,,,·····················,,····················································……1双低菜籽皮经不同方法处理效果的比较···············································……2不同处理对双低菜籽皮物理结构的影响········,······································……3不同处理饲粮对山羊生长性能的影响··················································,……26结论···,···········,······································································································……28参考文献·······,··················································································,···················……29致谢··········,·····,···,·············,·····,·············································································……35附录······················································································································……36005届硕士学位论文
动物营养与饲料的成本分析
你的论文准备往什么方向写,选题老师审核通过了没,有没有列个大纲让老师看一下写作方向? 老师有没有和你说论文往哪个方向写比较好?写论文之前,一定要写个大纲,这样老师,好确定了框架,避免以后论文修改过程中出现大改的情况!! 学校的格式要求、写作规范要注意,否则很可能发回来重新改,你要还有什么不明白或不懂可以问我,希望你能够顺利毕业,迈向新的人生。 (一)选题毕业论文(设计)题目应符合本专业的培养目标和教学要求,具有综合性和创新性。本科生要根据自己的实际情况和专业特长,选择适当的论文题目,但所写论文要与本专业所学课程有关。(二)查阅资料、列出论文提纲题目选定后,要在指导教师指导下开展调研和进行实验,搜集、查阅有关资料,进行加工、提炼,然后列出详细的写作提纲。(三)完成初稿根据所列提纲,按指导教师的意见认真完成初稿。(四)定稿初稿须经指导教师审阅,并按其意见和要求进行修改,然后定稿。一般毕业论文题目的选择最好不要太泛,越具体越好,而且老师希望学生能结合自己学过的知识对问题进行分析和解决。不知道你是否确定了选题,确定选题了接下来你需要根据选题去查阅前辈们的相关论文,看看人家是怎么规划论文整体框架的;其次就是需要自己动手收集资料了,进而整理和分析资料得出自己的论文框架;最后就是按照框架去组织论文了。你如果需要什么参考资料和范文我可以提供给你。还有什么不了解的可以直接问我,希望可以帮到你,祝写作过程顺利 毕业论文选题的方法: 一、尽快确定毕业论文的选题方向 在毕业论文工作布置后,每个人都应遵循选题的基本原则,在较短的时间内把选题的方向确定下来。从毕业论文题目的性质来看,基本上可以分为两大类:一类是社会主义现代化建设实践中提出的理论和实际问题;另一类是专业学科本身发展中存在的基本范畴和基本理论问题。大学生应根据自己的志趣和爱好,尽快从上述两大类中确定一个方向。 二、在初步调查研究的基础上选定毕业论文的具体题目在选题的方向确定以后,还要经过一定的调查和研究,来进一步确定选题的范围,以至最后选定具体题目。下面介绍两种常见的选题方法。 浏览捕捉法 :这种方法就是通过对占有的文献资料快速地、大量地阅读,在比较中来确定论文题目地方法。浏览,一般是在资料占有达到一定数量时集中一段时间进行,这样便于对资料作集中的比较和鉴别。浏览的目的是在咀嚼消化已有资料的过程中,提出问题,寻找自己的研究课题。这就需要对收集到的材料作一全面的阅读研究,主要的、次要的、不同角度的、不同观点的都应了解,不能看了一些资料,有了一点看法,就到此为止,急于动笔。也不能“先入为主”,以自己头脑中原有的观点或看了第一篇资料后得到的看法去决定取舍。而应冷静地、客观地对所有资料作认真的分析思考。在浩如烟海,内容丰富的资料中吸取营养,反复思考琢磨许多时候之后,必然会有所发现,这是搞科学研究的人时常会碰到的情形。 浏览捕捉法一般可按以下步骤进行: 第一步,广泛地浏览资料。在浏览中要注意勤作笔录,随时记下资料的纲目,记下资料中对自己影响最深刻的观点、论据、论证方法等,记下脑海中涌现的点滴体会。当然,手抄笔录并不等于有言必录,有文必录,而是要做细心的选择,有目的、有重点地摘录,当详则详,当略则略,一些相同的或类似的观点和材料则不必重复摘录,只需记下资料来源及页码就行,以避免浪费时间和精力。 第二步,是将阅读所得到的方方面面的内容,进行分类、排列、组合,从中寻找问题、发现问题,材料可按纲目分类,如分成: 系统介绍有关问题研究发展概况的资料; 对某一个问题研究情况的资料; 对同一问题几种不同观点的资料; 对某一问题研究最新的资料和成果等等。 第三步,将自己在研究中的体会与资料分别加以比较,找出哪些体会在资料中没有或部分没有;哪些体会虽然资料已有,但自己对此有不同看法;哪些体会和资料是基本一致的;哪些体会是在资料基础上的深化和发挥等等。经过几番深思熟虑的思考过程,就容易萌生自己的想法。把这种想法及时捕捉住,再作进一步的思考,选题的目标也就会渐渐明确起来。
有关动物营养与饲料论文选题怎么写啊
动物营养与饲料的成本分析
扫描版(部分文字乱码)分子生物学技术在动物营养学上的应用及其发展前景(上)摘要:本文从营养与基因表达调控、基因工程、转基因等三个方面综述了分子生物学技术在动物营养学中应用的最新进展,并对动物营养学的发展前景作了展望。自从发现双螺旋结构以来,分子生物学取得了飞跃性的发展,形成了以基因工程为主要内容的的现代分子生物学技术@在生物学、医学等研究中得到广泛的应用,几乎渗透到生命科学的每一个领域,成为研究和揭示生命现象本质和规律的一种重要工具。当前,世界各国都将分子生物学纳入本国科技发展的重点,可以预见,"21世纪将是生命科学的世纪,全世界所共同面临的许多重大问题,诸如饥饿与营养、疾病、能源与环境污染等问题的根本解决,在很大程度上将依赖于分子生物学技术的发展和应用。及时全面的了解和掌握分子生物学理论和技术的发展动态及研究热点,将具有重要的意义。就目前来看,我国动物营养学方面的研究工作基本尚处在机体水平:即在机体水平上研究各种营养素对机体的作用、在机体内的代谢与平衡、影响机体吸收营养素的因素等问题。分子水平方面的研究还刚刚起步,尚处于初级阶段。动物机体的生理病理变化,如生长发育、新陈代谢、遗传变异、免疫与疾病等,就本质而言,都是动物基因的表达调控发生了改变的结果,许多生理现象的彻底阐明,最终需要在基因水平上进行解释,所以动物营养学的各方面研究应与分子生物学技术,尤其是基因工程技术相结合,从分子水平上来解释各种营养素对机体的作用机制、动物机体的生理病理变化等问题,这也是动物营养学今后发展的必然趋势之一。*营养与基因的表达调控随着分子生物学技术不断发展,越来越多与代谢有关的动物基因被克隆和鉴定,人们对营养与基因调控的关系越来越感兴趣。营养与动物基因表达调控的研究已成为当今动物营养学研究的一个热点领域;如何通过改变日粮组成成分来调节体内相关基因的表达,从而使动物体处于最佳生长状况已成为现代动物营养学研究的重点;通过营养对动物基因表达的调控途径及其机制的研究,将为人们如何更加有效地对某些特定有益基因的表达提供理论依据。已有大量证据表明,主要的营养物质如糖、脂肪酸、氨基酸以及一些微量元素(如锌)对动物体内许多基因的表达都有影响。!"!营养对磷酸烯醇式丙酮酸激酶基因表达的调控PEPCK是动物肝和肾中糖元异生作用的关键酶,目前较为研究清楚的是日粮中糖含量对PEPCK基因表达的调控。糖类对PEPCK的调控主要是通过对其启动子的作用,当动物进食含有大量糖类的饲料时,PEPCK的启动了就会关闭,从而导致ABA8C水平大幅度下降,而当禁食或饲喂高蛋白质低糖的饲料时,PEPCK的启动子就会处于打开状态,从而PEPCK水平得到大幅度提高,其具体调控机制大致如下:?556D4(*0)#)等通过对大鼠ABA8C基因的分析表明,ABA8C基因启动子位于1 E+至F#,之间,其中包含了大多数激素调控基因转录所必需的组织特异性调控元件。日粮中糖的含量水平会影响胰岛素、;?GA等激素的相对水平,而胰岛素与;?GA等激素相对水平又会影响到特异性!"#!转录因子的活性,特异性转录因子与$%$&’启动子上的相应调控元件结合与否,又会影响$%$&’基因的表达(,)。现有大量证据表明,$%$&’基因一系列复杂的调控元件中,有包括胰岛素、甲状腺激素、糖皮质激素、视黄酸对$%$&’基因转录的正调控元件和胰岛素对$%$&’基因转录的负控调元件,在上述调控元件中,*+,$调控元件-&%/和$(-0/调控元件是最重要的两种,*+,$对$%$&’基因的诱导和胰岛素对$%$&’基因的抑制作用就是通过这两个调控元件来进行调控的。因此,当进食含大量糖类的饲料时,由于*+,$水平的急剧下降以及胰岛素水平的急剧上升,从而抑制$%$&’基因的表达,导致肝中$%$&’水平大幅度下降,当禁食或饲喂高蛋白低糖的饲料时,则情况恰好相反。!"#营养对脂肪酸合成酶($%&)基因表达的调控1+2是脂肪酸合成的主要限制酶,存在于脂肪、肝脏及肺等组织中,在动物体内起催化丙二酰&3+连续缩合成长链脂肪酸的反应,其活性高低将直接控制着体内脂肪合成的强弱,从而影响整个机体中脂肪的含量。有关营养与1+2基因的表达调控,2!4!&56789-:;;(/曾报道:糖类能诱导1+2基因的转录,而脂肪则抑制这种诱导的表达。&3<=9等(:;;>)试验研究也表明,当给禁食后的成年鼠饲喂含高糖低脂肪的饲料时,1+2基因的表达就增强,而且相应的?@+含量的增加幅度与碳水化合物的摄入量也成正比。糖类对1+2基因表达的影响。为区分活体中激素水平变化的协同作用,13
提高双低菜籽皮对反自动物营养价值的研摘要本研究以双低菜籽皮的中性洗涤纤维(NeutralDetergentFiber,NDF)含量为评定指标。采用混合嵌套设计从干式NaOH法(处理时间分别为d1、d2、3d)、尿素氨化法(处理时间分别为1d0、1d5、ZOd)、碱化一氨化复合处理(处理时间分别为15d、ZOd、25d)筛选出最佳处理组及其处理时间;采用L(3‘)正交设计筛选出最佳配比的纤维素酶、B一葡聚糖酶、木聚糖酶和a一淀粉酶处理组;从而得到最佳化学处理组和最佳复合酶制剂处理组。采用扫描电子显微镜(SacunnigEleetrnoMcriosocpe,SEM)技术分析上述最佳处理组处理的双低菜籽皮的结构;并分别以稻草、未处理双低菜籽皮、经最佳化学组处理的双低菜籽皮、经最佳复合酶制剂组处理的双低菜籽皮为粗料配制不同日粮,研究其对湖北麻城黑山羊的生长性能的影响。试验结果如下:与对照组(未处理组)相比,双低菜籽皮经干式Na0H法、尿素氨化法、碱化-氨化复合法处理后中性洗涤纤维(NDF)含量降低,中性洗涤纤维2h4降解率升高。双低菜籽皮经不同化学方法处理后,中性洗涤纤维(NDF)含量组间差异极显著P(<01),中性洗涤纤维2h4降解率组间差异极显著P(<01);双低菜籽皮经同种方法不同时间处理后,时间对NDF含量及中性洗涤纤维24h降解率的影响是极显著(P<01)。就中性洗涤纤维2h4降解率而言,干式NaOH处理组比对照组的分别提高了22%、16%、58,64%,尿素氨化处理组比对照组的分别提高了81%、()7%、巧64%,碱化一氨化复合处理组比对照组的分别提高了88%、04%、79%。双低菜籽皮经不同配比的复合酶制剂处理后NDF含量组间差异不显著P(>005),中性洗涤纤维2h4降解率组间差异不显著P(>005)。与对照组相比,NDF含量均下降,分别降低了15%、59%、56%、81%、42%、57%、%、62%、05%;中性洗涤纤维24h降解率均有所提高,分别提高了07%、89,05%、75%、42%、29%、77%、72%、96%、74%。扫描电镜观察发现处理前后双低菜籽皮的物理结构变化显著。未处理的双低菜籽皮结构紧密,细胞器清晰可见;经过碱化一氨化复合处理之后,薄壁组织膨胀,形成一些“孔穴”结构,并且大部分的细胞器解体脱落:经过复合酶制剂处理后双低菜籽皮表面光滑,“孔穴”结构更加规则,并且细胞器基本完全解体脱落。表明双低菜籽皮经过处理后细胞壁疏松,为瘤胃液的渗透提供有利的条件,从而提高双低当动物营养价值的研究菜籽皮的利用效率。两种处理方法处理的双低菜籽皮组与稻草组相比,山羊的采食量、日增重、料肉比差异显著(P<005);与未处理的双低菜籽皮组相比,差异不显著P(>005),但山羊的采食量和日增重有所提高,料肉比下降。结果表明,双低菜籽皮经碱化一氨化复合法在常温下处理20d后效果最佳;双低菜籽皮的最佳复合酶制剂的配比为纤维素酶38469、B一葡聚糖酶16679、木聚糖酶20009和a一淀粉酶01259(添加比例为在5009双低菜籽皮中的含量)。碱化一氨化复合处理和复合酶制剂处理能够提高双低菜籽皮的营养价值,并且饲喂经最佳处理组处理的双低菜籽皮可以提高山羊的生长性能。关键词:双低菜籽皮;氨化;复合酶制剂;扫描电镜;瘤胃尼龙袋法目录中文摘要···············,····································,·················,·······································……I英文摘要······················································································,····················,··……1111,前言·······························,··················································································……1开发双低菜籽皮饲料的重要性·················,··············································……2双低菜籽皮的特点和营养价值·······························································……3低质粗饲料的处理方法·····,·,··,······,··················,······································……4低质粗饲料在反当动物饲料利用中存在的问题························,··········……5本试验研究的目的和意义·······································································……材料与方法······································,·······························································……1样品的采集·································,·····························································……2处理双低菜籽皮的化学方法·····,·····························································……3处理双低菜籽皮的酶制剂方法,·········,·············································,······……4双低菜籽皮营养成分瘤胃降解率的测定···············································……5扫描电子显微镜分析···············································································……26山羊饲养试验···························································································……7检测指标···································································································……132,8一计算公式与数据处理·······················································,·····················……‘’结果与分析··,·····,·······,··,,,···,····,,······································································……143,1双低菜籽皮的主要成分含量········,··························································一2化学处理双低菜籽皮的成分分析···············································,···········……3复合酶制剂处理双低菜籽皮的成分分析···············································……4扫描电镜分析处理前后双低菜籽皮结构的变化···································……5不同处理饲粮对山羊生长性能的影响···················································……讨论······,···················,···,·····,,,·····················,,····················································……1双低菜籽皮经不同方法处理效果的比较···············································……2不同处理对双低菜籽皮物理结构的影响········,······································……3不同处理饲粮对山羊生长性能的影响··················································,……26结论···,···········,······································································································……28参考文献·······,··················································································,···················……29致谢··········,·····,···,·············,·····,·············································································……35附录······················································································································……36005届硕士学位论文
有关动物营养与饲料论文选题怎么写呀
提高双低菜籽皮对反自动物营养价值的研摘要本研究以双低菜籽皮的中性洗涤纤维(NeutralDetergentFiber,NDF)含量为评定指标。采用混合嵌套设计从干式NaOH法(处理时间分别为d1、d2、3d)、尿素氨化法(处理时间分别为1d0、1d5、ZOd)、碱化一氨化复合处理(处理时间分别为15d、ZOd、25d)筛选出最佳处理组及其处理时间;采用L(3‘)正交设计筛选出最佳配比的纤维素酶、B一葡聚糖酶、木聚糖酶和a一淀粉酶处理组;从而得到最佳化学处理组和最佳复合酶制剂处理组。采用扫描电子显微镜(SacunnigEleetrnoMcriosocpe,SEM)技术分析上述最佳处理组处理的双低菜籽皮的结构;并分别以稻草、未处理双低菜籽皮、经最佳化学组处理的双低菜籽皮、经最佳复合酶制剂组处理的双低菜籽皮为粗料配制不同日粮,研究其对湖北麻城黑山羊的生长性能的影响。试验结果如下:与对照组(未处理组)相比,双低菜籽皮经干式Na0H法、尿素氨化法、碱化-氨化复合法处理后中性洗涤纤维(NDF)含量降低,中性洗涤纤维2h4降解率升高。双低菜籽皮经不同化学方法处理后,中性洗涤纤维(NDF)含量组间差异极显著P(<01),中性洗涤纤维2h4降解率组间差异极显著P(<01);双低菜籽皮经同种方法不同时间处理后,时间对NDF含量及中性洗涤纤维24h降解率的影响是极显著(P<01)。就中性洗涤纤维2h4降解率而言,干式NaOH处理组比对照组的分别提高了22%、16%、58,64%,尿素氨化处理组比对照组的分别提高了81%、()7%、巧64%,碱化一氨化复合处理组比对照组的分别提高了88%、04%、79%。双低菜籽皮经不同配比的复合酶制剂处理后NDF含量组间差异不显著P(>005),中性洗涤纤维2h4降解率组间差异不显著P(>005)。与对照组相比,NDF含量均下降,分别降低了15%、59%、56%、81%、42%、57%、%、62%、05%;中性洗涤纤维24h降解率均有所提高,分别提高了07%、89,05%、75%、42%、29%、77%、72%、96%、74%。扫描电镜观察发现处理前后双低菜籽皮的物理结构变化显著。未处理的双低菜籽皮结构紧密,细胞器清晰可见;经过碱化一氨化复合处理之后,薄壁组织膨胀,形成一些“孔穴”结构,并且大部分的细胞器解体脱落:经过复合酶制剂处理后双低菜籽皮表面光滑,“孔穴”结构更加规则,并且细胞器基本完全解体脱落。表明双低菜籽皮经过处理后细胞壁疏松,为瘤胃液的渗透提供有利的条件,从而提高双低当动物营养价值的研究菜籽皮的利用效率。两种处理方法处理的双低菜籽皮组与稻草组相比,山羊的采食量、日增重、料肉比差异显著(P<005);与未处理的双低菜籽皮组相比,差异不显著P(>005),但山羊的采食量和日增重有所提高,料肉比下降。结果表明,双低菜籽皮经碱化一氨化复合法在常温下处理20d后效果最佳;双低菜籽皮的最佳复合酶制剂的配比为纤维素酶38469、B一葡聚糖酶16679、木聚糖酶20009和a一淀粉酶01259(添加比例为在5009双低菜籽皮中的含量)。碱化一氨化复合处理和复合酶制剂处理能够提高双低菜籽皮的营养价值,并且饲喂经最佳处理组处理的双低菜籽皮可以提高山羊的生长性能。关键词:双低菜籽皮;氨化;复合酶制剂;扫描电镜;瘤胃尼龙袋法目录中文摘要···············,····································,·················,·······································……I英文摘要······················································································,····················,··……1111,前言·······························,··················································································……1开发双低菜籽皮饲料的重要性·················,··············································……2双低菜籽皮的特点和营养价值·······························································……3低质粗饲料的处理方法·····,·,··,······,··················,······································……4低质粗饲料在反当动物饲料利用中存在的问题························,··········……5本试验研究的目的和意义·······································································……材料与方法······································,·······························································……1样品的采集·································,·····························································……2处理双低菜籽皮的化学方法·····,·····························································……3处理双低菜籽皮的酶制剂方法,·········,·············································,······……4双低菜籽皮营养成分瘤胃降解率的测定···············································……5扫描电子显微镜分析···············································································……26山羊饲养试验···························································································……7检测指标···································································································……132,8一计算公式与数据处理·······················································,·····················……‘’结果与分析··,·····,·······,··,,,···,····,,······································································……143,1双低菜籽皮的主要成分含量········,··························································一2化学处理双低菜籽皮的成分分析···············································,···········……3复合酶制剂处理双低菜籽皮的成分分析···············································……4扫描电镜分析处理前后双低菜籽皮结构的变化···································……5不同处理饲粮对山羊生长性能的影响···················································……讨论······,···················,···,·····,,,·····················,,····················································……1双低菜籽皮经不同方法处理效果的比较···············································……2不同处理对双低菜籽皮物理结构的影响········,······································……3不同处理饲粮对山羊生长性能的影响··················································,……26结论···,···········,······································································································……28参考文献·······,··················································································,···················……29致谢··········,·····,···,·············,·····,·············································································……35附录······················································································································……36005届硕士学位论文
饲料安全与畜产品质量研究饲用抗生素的替代技术(如药用植物及提取物、抗菌肽等),在保证动物高效生产的前提下,采用无抗生素的绿色饲料,生产安全的畜产品。研究影响猪、鸡肉质性状形成的分子机理、代谢途径、影响因素,通过有效的营养调控,生产优质的畜产品。单胃动物营养与饲料在重点掌握本领域及相关领域国内外研究动态、研究热点、研究进展及行业发展趋势的基础上,本研究方向主要从事猪、鸡等单胃动物营养需要以及与单胃动物相关的营养与饲料、营养生理、营养调控、营养与免疫、营养与环境的研究和新型饲料与饲料添加剂的开发与安全性评价。通过相关专题理论的学习和学位论文试验设计、课题实施、论文撰写等环节,培养从事单胃动物营养与饲料研究和生产的高级专业人才。反刍动物营养与饲料结合我国奶牛饲养的条件,通过奶牛营养参数和饲料营养价值评定、优质粗饲料生产和科学利用技术、日粮营养平衡技术,奶牛高效、精细化饲养管理和营养检测技术,同时开展奶牛营养与代谢调控等前瞻性研究,应用系统整体营养调控指导思想来解决当前我国奶牛生产存在的奶牛单产低,奶质差和营养代谢病多的问题。通过本方向的研究最终形成适合不同区域或不同养殖模式的标准化奶牛饲养技术规范。动物行为福利与环境本方向主要研究集约化生产条件下畜禽异常行为产生的机制、影响动物福利的因素,以及有利于机体健康、生产性能提高的畜禽养殖新工艺的探索。动物分子营养与饲料生物技术本研究方向主要从事营养素与基因之间的相互作用(包括营养与营养素之间、营养素与基因之间、基因与基因之间的相互作用)及其对机体健康影响的规律和机制,利用现代生物技术开发新的饲料资源,提高饲料的利用营养价值及转化率,降低饲料中的抗营养因子和毒素及生产成本,节省饲料等方面的研究。饲料与畜产品IT技术研究饲料配制与畜产品生产过程中的数据电脑管理和安全质量的数字化监控体系。通过对饲料—养殖—畜产品—消费者流程中的每个环节、每项措施、每个成分进行危害评估及关键控制点的分析检验,对整个生产链全过程制定可操作规范体系,使原料供应、加工生产、包装运输、销售消费都能在统一的操作规范下进行,从而保证畜产品的安全性。
扫描版(部分文字乱码)分子生物学技术在动物营养学上的应用及其发展前景(上)摘要:本文从营养与基因表达调控、基因工程、转基因等三个方面综述了分子生物学技术在动物营养学中应用的最新进展,并对动物营养学的发展前景作了展望。自从发现双螺旋结构以来,分子生物学取得了飞跃性的发展,形成了以基因工程为主要内容的的现代分子生物学技术@在生物学、医学等研究中得到广泛的应用,几乎渗透到生命科学的每一个领域,成为研究和揭示生命现象本质和规律的一种重要工具。当前,世界各国都将分子生物学纳入本国科技发展的重点,可以预见,"21世纪将是生命科学的世纪,全世界所共同面临的许多重大问题,诸如饥饿与营养、疾病、能源与环境污染等问题的根本解决,在很大程度上将依赖于分子生物学技术的发展和应用。及时全面的了解和掌握分子生物学理论和技术的发展动态及研究热点,将具有重要的意义。就目前来看,我国动物营养学方面的研究工作基本尚处在机体水平:即在机体水平上研究各种营养素对机体的作用、在机体内的代谢与平衡、影响机体吸收营养素的因素等问题。分子水平方面的研究还刚刚起步,尚处于初级阶段。动物机体的生理病理变化,如生长发育、新陈代谢、遗传变异、免疫与疾病等,就本质而言,都是动物基因的表达调控发生了改变的结果,许多生理现象的彻底阐明,最终需要在基因水平上进行解释,所以动物营养学的各方面研究应与分子生物学技术,尤其是基因工程技术相结合,从分子水平上来解释各种营养素对机体的作用机制、动物机体的生理病理变化等问题,这也是动物营养学今后发展的必然趋势之一。*营养与基因的表达调控随着分子生物学技术不断发展,越来越多与代谢有关的动物基因被克隆和鉴定,人们对营养与基因调控的关系越来越感兴趣。营养与动物基因表达调控的研究已成为当今动物营养学研究的一个热点领域;如何通过改变日粮组成成分来调节体内相关基因的表达,从而使动物体处于最佳生长状况已成为现代动物营养学研究的重点;通过营养对动物基因表达的调控途径及其机制的研究,将为人们如何更加有效地对某些特定有益基因的表达提供理论依据。已有大量证据表明,主要的营养物质如糖、脂肪酸、氨基酸以及一些微量元素(如锌)对动物体内许多基因的表达都有影响。!"!营养对磷酸烯醇式丙酮酸激酶基因表达的调控PEPCK是动物肝和肾中糖元异生作用的关键酶,目前较为研究清楚的是日粮中糖含量对PEPCK基因表达的调控。糖类对PEPCK的调控主要是通过对其启动子的作用,当动物进食含有大量糖类的饲料时,PEPCK的启动了就会关闭,从而导致ABA8C水平大幅度下降,而当禁食或饲喂高蛋白质低糖的饲料时,PEPCK的启动子就会处于打开状态,从而PEPCK水平得到大幅度提高,其具体调控机制大致如下:?556D4(*0)#)等通过对大鼠ABA8C基因的分析表明,ABA8C基因启动子位于1 E+至F#,之间,其中包含了大多数激素调控基因转录所必需的组织特异性调控元件。日粮中糖的含量水平会影响胰岛素、;?GA等激素的相对水平,而胰岛素与;?GA等激素相对水平又会影响到特异性!"#!转录因子的活性,特异性转录因子与$%$&’启动子上的相应调控元件结合与否,又会影响$%$&’基因的表达(,)。现有大量证据表明,$%$&’基因一系列复杂的调控元件中,有包括胰岛素、甲状腺激素、糖皮质激素、视黄酸对$%$&’基因转录的正调控元件和胰岛素对$%$&’基因转录的负控调元件,在上述调控元件中,*+,$调控元件-&%/和$(-0/调控元件是最重要的两种,*+,$对$%$&’基因的诱导和胰岛素对$%$&’基因的抑制作用就是通过这两个调控元件来进行调控的。因此,当进食含大量糖类的饲料时,由于*+,$水平的急剧下降以及胰岛素水平的急剧上升,从而抑制$%$&’基因的表达,导致肝中$%$&’水平大幅度下降,当禁食或饲喂高蛋白低糖的饲料时,则情况恰好相反。!"#营养对脂肪酸合成酶($%&)基因表达的调控1+2是脂肪酸合成的主要限制酶,存在于脂肪、肝脏及肺等组织中,在动物体内起催化丙二酰&3+连续缩合成长链脂肪酸的反应,其活性高低将直接控制着体内脂肪合成的强弱,从而影响整个机体中脂肪的含量。有关营养与1+2基因的表达调控,2!4!&56789-:;;(/曾报道:糖类能诱导1+2基因的转录,而脂肪则抑制这种诱导的表达。&3<=9等(:;;>)试验研究也表明,当给禁食后的成年鼠饲喂含高糖低脂肪的饲料时,1+2基因的表达就增强,而且相应的?@+含量的增加幅度与碳水化合物的摄入量也成正比。糖类对1+2基因表达的影响。为区分活体中激素水平变化的协同作用,13
有关动物营养与饲料论文题目怎么写
提高双低菜籽皮对反自动物营养价值的研摘要本研究以双低菜籽皮的中性洗涤纤维(NeutralDetergentFiber,NDF)含量为评定指标。采用混合嵌套设计从干式NaOH法(处理时间分别为d1、d2、3d)、尿素氨化法(处理时间分别为1d0、1d5、ZOd)、碱化一氨化复合处理(处理时间分别为15d、ZOd、25d)筛选出最佳处理组及其处理时间;采用L(3‘)正交设计筛选出最佳配比的纤维素酶、B一葡聚糖酶、木聚糖酶和a一淀粉酶处理组;从而得到最佳化学处理组和最佳复合酶制剂处理组。采用扫描电子显微镜(SacunnigEleetrnoMcriosocpe,SEM)技术分析上述最佳处理组处理的双低菜籽皮的结构;并分别以稻草、未处理双低菜籽皮、经最佳化学组处理的双低菜籽皮、经最佳复合酶制剂组处理的双低菜籽皮为粗料配制不同日粮,研究其对湖北麻城黑山羊的生长性能的影响。试验结果如下:与对照组(未处理组)相比,双低菜籽皮经干式Na0H法、尿素氨化法、碱化-氨化复合法处理后中性洗涤纤维(NDF)含量降低,中性洗涤纤维2h4降解率升高。双低菜籽皮经不同化学方法处理后,中性洗涤纤维(NDF)含量组间差异极显著P(<01),中性洗涤纤维2h4降解率组间差异极显著P(<01);双低菜籽皮经同种方法不同时间处理后,时间对NDF含量及中性洗涤纤维24h降解率的影响是极显著(P<01)。就中性洗涤纤维2h4降解率而言,干式NaOH处理组比对照组的分别提高了22%、16%、58,64%,尿素氨化处理组比对照组的分别提高了81%、()7%、巧64%,碱化一氨化复合处理组比对照组的分别提高了88%、04%、79%。双低菜籽皮经不同配比的复合酶制剂处理后NDF含量组间差异不显著P(>005),中性洗涤纤维2h4降解率组间差异不显著P(>005)。与对照组相比,NDF含量均下降,分别降低了15%、59%、56%、81%、42%、57%、%、62%、05%;中性洗涤纤维24h降解率均有所提高,分别提高了07%、89,05%、75%、42%、29%、77%、72%、96%、74%。扫描电镜观察发现处理前后双低菜籽皮的物理结构变化显著。未处理的双低菜籽皮结构紧密,细胞器清晰可见;经过碱化一氨化复合处理之后,薄壁组织膨胀,形成一些“孔穴”结构,并且大部分的细胞器解体脱落:经过复合酶制剂处理后双低菜籽皮表面光滑,“孔穴”结构更加规则,并且细胞器基本完全解体脱落。表明双低菜籽皮经过处理后细胞壁疏松,为瘤胃液的渗透提供有利的条件,从而提高双低当动物营养价值的研究菜籽皮的利用效率。两种处理方法处理的双低菜籽皮组与稻草组相比,山羊的采食量、日增重、料肉比差异显著(P<005);与未处理的双低菜籽皮组相比,差异不显著P(>005),但山羊的采食量和日增重有所提高,料肉比下降。结果表明,双低菜籽皮经碱化一氨化复合法在常温下处理20d后效果最佳;双低菜籽皮的最佳复合酶制剂的配比为纤维素酶38469、B一葡聚糖酶16679、木聚糖酶20009和a一淀粉酶01259(添加比例为在5009双低菜籽皮中的含量)。碱化一氨化复合处理和复合酶制剂处理能够提高双低菜籽皮的营养价值,并且饲喂经最佳处理组处理的双低菜籽皮可以提高山羊的生长性能。关键词:双低菜籽皮;氨化;复合酶制剂;扫描电镜;瘤胃尼龙袋法目录中文摘要···············,····································,·················,·······································……I英文摘要······················································································,····················,··……1111,前言·······························,··················································································……1开发双低菜籽皮饲料的重要性·················,··············································……2双低菜籽皮的特点和营养价值·······························································……3低质粗饲料的处理方法·····,·,··,······,··················,······································……4低质粗饲料在反当动物饲料利用中存在的问题························,··········……5本试验研究的目的和意义·······································································……材料与方法······································,·······························································……1样品的采集·································,·····························································……2处理双低菜籽皮的化学方法·····,·····························································……3处理双低菜籽皮的酶制剂方法,·········,·············································,······……4双低菜籽皮营养成分瘤胃降解率的测定···············································……5扫描电子显微镜分析···············································································……26山羊饲养试验···························································································……7检测指标···································································································……132,8一计算公式与数据处理·······················································,·····················……‘’结果与分析··,·····,·······,··,,,···,····,,······································································……143,1双低菜籽皮的主要成分含量········,··························································一2化学处理双低菜籽皮的成分分析···············································,···········……3复合酶制剂处理双低菜籽皮的成分分析···············································……4扫描电镜分析处理前后双低菜籽皮结构的变化···································……5不同处理饲粮对山羊生长性能的影响···················································……讨论······,···················,···,·····,,,·····················,,····················································……1双低菜籽皮经不同方法处理效果的比较···············································……2不同处理对双低菜籽皮物理结构的影响········,······································……3不同处理饲粮对山羊生长性能的影响··················································,……26结论···,···········,······································································································……28参考文献·······,··················································································,···················……29致谢··········,·····,···,·············,·····,·············································································……35附录······················································································································……36005届硕士学位论文
我也不清楚你熟悉那些方面的,或者你想写那些方面的都不太清楚。给你些选题你自己参考参考下。影响毕节地区饲料质量安全的因素及对策的研究 香鱼幼鱼饲料蛋白需要及膨化加工的研究 陕西省饲料产品质量安全面临的问题与对策研究 刺参幼参饲料原料选择与蛋白质营养需求的研究 饲料蛋白质、脂肪水平与投喂频率对大黄鱼幼鱼生长和饲料利用的影响 中国饲料安全现状分析及监督管理策略 C饲料公司进入油脂业的模式及运作研究 近红外光谱分析技术在饲料品质快速检测中的应用研究 大黄鱼膨化饲料溶失率及对水环境中氮、磷含量的影响 荆州地区猪场饲料真菌的调查 中华鳖对低蛋白和红鱼粉饲料利用的研究 影响我国饲料质量安全的因素及对策的研究 斑节对虾饲料鱼粉替代研究及商品饲料环境安全性评价 基于作业与标准的饲料行业成本管理 山羊饲料养分瘤胃降解规律的研究 中国奶牛饲料利用现状及发展前景 饲料企业产品质量控制 不同能量饲料的组成差异及瘤胃降解特性的比较研究 饲料中脂肪与蛋白质水平对大口黑鲈生长、体组成、非特异性免疫和血液学的影响 山羊常用饲料瘤胃降解率的研究 黄颡鱼幼鱼对饲料中蛋白、能量、钙、磷和脂肪酸需要量 家蚕颗粒人工饲料育的研究 我国饲料粮消耗现状分析与猪、鸡饲料粮需求预测 小鼠不同发育阶段饲喂高能饲料对若干生理指标的影响 半滑舌鳎和漠斑牙鲆饲料性能的研究
动物营养与饲料的成本分析
有关动物营养与饲料论文选题方向怎么写
提高双低菜籽皮对反自动物营养价值的研摘要本研究以双低菜籽皮的中性洗涤纤维(NeutralDetergentFiber,NDF)含量为评定指标。采用混合嵌套设计从干式NaOH法(处理时间分别为d1、d2、3d)、尿素氨化法(处理时间分别为1d0、1d5、ZOd)、碱化一氨化复合处理(处理时间分别为15d、ZOd、25d)筛选出最佳处理组及其处理时间;采用L(3‘)正交设计筛选出最佳配比的纤维素酶、B一葡聚糖酶、木聚糖酶和a一淀粉酶处理组;从而得到最佳化学处理组和最佳复合酶制剂处理组。采用扫描电子显微镜(SacunnigEleetrnoMcriosocpe,SEM)技术分析上述最佳处理组处理的双低菜籽皮的结构;并分别以稻草、未处理双低菜籽皮、经最佳化学组处理的双低菜籽皮、经最佳复合酶制剂组处理的双低菜籽皮为粗料配制不同日粮,研究其对湖北麻城黑山羊的生长性能的影响。试验结果如下:与对照组(未处理组)相比,双低菜籽皮经干式Na0H法、尿素氨化法、碱化-氨化复合法处理后中性洗涤纤维(NDF)含量降低,中性洗涤纤维2h4降解率升高。双低菜籽皮经不同化学方法处理后,中性洗涤纤维(NDF)含量组间差异极显著P(<01),中性洗涤纤维2h4降解率组间差异极显著P(<01);双低菜籽皮经同种方法不同时间处理后,时间对NDF含量及中性洗涤纤维24h降解率的影响是极显著(P<01)。就中性洗涤纤维2h4降解率而言,干式NaOH处理组比对照组的分别提高了22%、16%、58,64%,尿素氨化处理组比对照组的分别提高了81%、()7%、巧64%,碱化一氨化复合处理组比对照组的分别提高了88%、04%、79%。双低菜籽皮经不同配比的复合酶制剂处理后NDF含量组间差异不显著P(>005),中性洗涤纤维2h4降解率组间差异不显著P(>005)。与对照组相比,NDF含量均下降,分别降低了15%、59%、56%、81%、42%、57%、%、62%、05%;中性洗涤纤维24h降解率均有所提高,分别提高了07%、89,05%、75%、42%、29%、77%、72%、96%、74%。扫描电镜观察发现处理前后双低菜籽皮的物理结构变化显著。未处理的双低菜籽皮结构紧密,细胞器清晰可见;经过碱化一氨化复合处理之后,薄壁组织膨胀,形成一些“孔穴”结构,并且大部分的细胞器解体脱落:经过复合酶制剂处理后双低菜籽皮表面光滑,“孔穴”结构更加规则,并且细胞器基本完全解体脱落。表明双低菜籽皮经过处理后细胞壁疏松,为瘤胃液的渗透提供有利的条件,从而提高双低当动物营养价值的研究菜籽皮的利用效率。两种处理方法处理的双低菜籽皮组与稻草组相比,山羊的采食量、日增重、料肉比差异显著(P<005);与未处理的双低菜籽皮组相比,差异不显著P(>005),但山羊的采食量和日增重有所提高,料肉比下降。结果表明,双低菜籽皮经碱化一氨化复合法在常温下处理20d后效果最佳;双低菜籽皮的最佳复合酶制剂的配比为纤维素酶38469、B一葡聚糖酶16679、木聚糖酶20009和a一淀粉酶01259(添加比例为在5009双低菜籽皮中的含量)。碱化一氨化复合处理和复合酶制剂处理能够提高双低菜籽皮的营养价值,并且饲喂经最佳处理组处理的双低菜籽皮可以提高山羊的生长性能。关键词:双低菜籽皮;氨化;复合酶制剂;扫描电镜;瘤胃尼龙袋法目录中文摘要···············,····································,·················,·······································……I英文摘要······················································································,····················,··……1111,前言·······························,··················································································……1开发双低菜籽皮饲料的重要性·················,··············································……2双低菜籽皮的特点和营养价值·······························································……3低质粗饲料的处理方法·····,·,··,······,··················,······································……4低质粗饲料在反当动物饲料利用中存在的问题························,··········……5本试验研究的目的和意义·······································································……材料与方法······································,·······························································……1样品的采集·································,·····························································……2处理双低菜籽皮的化学方法·····,·····························································……3处理双低菜籽皮的酶制剂方法,·········,·············································,······……4双低菜籽皮营养成分瘤胃降解率的测定···············································……5扫描电子显微镜分析···············································································……26山羊饲养试验···························································································……7检测指标···································································································……132,8一计算公式与数据处理·······················································,·····················……‘’结果与分析··,·····,·······,··,,,···,····,,······································································……143,1双低菜籽皮的主要成分含量········,··························································一2化学处理双低菜籽皮的成分分析···············································,···········……3复合酶制剂处理双低菜籽皮的成分分析···············································……4扫描电镜分析处理前后双低菜籽皮结构的变化···································……5不同处理饲粮对山羊生长性能的影响···················································……讨论······,···················,···,·····,,,·····················,,····················································……1双低菜籽皮经不同方法处理效果的比较···············································……2不同处理对双低菜籽皮物理结构的影响········,······································……3不同处理饲粮对山羊生长性能的影响··················································,……26结论···,···········,······································································································……28参考文献·······,··················································································,···················……29致谢··········,·····,···,·············,·····,·············································································……35附录······················································································································……36005届硕士学位论文
你的论文准备往什么方向写,选题老师审核通过了没,有没有列个大纲让老师看一下写作方向? 老师有没有和你说论文往哪个方向写比较好?写论文之前,一定要写个大纲,这样老师,好确定了框架,避免以后论文修改过程中出现大改的情况!! 学校的格式要求、写作规范要注意,否则很可能发回来重新改,你要还有什么不明白或不懂可以问我,希望你能够顺利毕业,迈向新的人生。 (一)选题毕业论文(设计)题目应符合本专业的培养目标和教学要求,具有综合性和创新性。本科生要根据自己的实际情况和专业特长,选择适当的论文题目,但所写论文要与本专业所学课程有关。(二)查阅资料、列出论文提纲题目选定后,要在指导教师指导下开展调研和进行实验,搜集、查阅有关资料,进行加工、提炼,然后列出详细的写作提纲。(三)完成初稿根据所列提纲,按指导教师的意见认真完成初稿。(四)定稿初稿须经指导教师审阅,并按其意见和要求进行修改,然后定稿。一般毕业论文题目的选择最好不要太泛,越具体越好,而且老师希望学生能结合自己学过的知识对问题进行分析和解决。不知道你是否确定了选题,确定选题了接下来你需要根据选题去查阅前辈们的相关论文,看看人家是怎么规划论文整体框架的;其次就是需要自己动手收集资料了,进而整理和分析资料得出自己的论文框架;最后就是按照框架去组织论文了。你如果需要什么参考资料和范文我可以提供给你。还有什么不了解的可以直接问我,希望可以帮到你,祝写作过程顺利 毕业论文选题的方法: 一、尽快确定毕业论文的选题方向 在毕业论文工作布置后,每个人都应遵循选题的基本原则,在较短的时间内把选题的方向确定下来。从毕业论文题目的性质来看,基本上可以分为两大类:一类是社会主义现代化建设实践中提出的理论和实际问题;另一类是专业学科本身发展中存在的基本范畴和基本理论问题。大学生应根据自己的志趣和爱好,尽快从上述两大类中确定一个方向。 二、在初步调查研究的基础上选定毕业论文的具体题目在选题的方向确定以后,还要经过一定的调查和研究,来进一步确定选题的范围,以至最后选定具体题目。下面介绍两种常见的选题方法。 浏览捕捉法 :这种方法就是通过对占有的文献资料快速地、大量地阅读,在比较中来确定论文题目地方法。浏览,一般是在资料占有达到一定数量时集中一段时间进行,这样便于对资料作集中的比较和鉴别。浏览的目的是在咀嚼消化已有资料的过程中,提出问题,寻找自己的研究课题。这就需要对收集到的材料作一全面的阅读研究,主要的、次要的、不同角度的、不同观点的都应了解,不能看了一些资料,有了一点看法,就到此为止,急于动笔。也不能“先入为主”,以自己头脑中原有的观点或看了第一篇资料后得到的看法去决定取舍。而应冷静地、客观地对所有资料作认真的分析思考。在浩如烟海,内容丰富的资料中吸取营养,反复思考琢磨许多时候之后,必然会有所发现,这是搞科学研究的人时常会碰到的情形。 浏览捕捉法一般可按以下步骤进行: 第一步,广泛地浏览资料。在浏览中要注意勤作笔录,随时记下资料的纲目,记下资料中对自己影响最深刻的观点、论据、论证方法等,记下脑海中涌现的点滴体会。当然,手抄笔录并不等于有言必录,有文必录,而是要做细心的选择,有目的、有重点地摘录,当详则详,当略则略,一些相同的或类似的观点和材料则不必重复摘录,只需记下资料来源及页码就行,以避免浪费时间和精力。 第二步,是将阅读所得到的方方面面的内容,进行分类、排列、组合,从中寻找问题、发现问题,材料可按纲目分类,如分成: 系统介绍有关问题研究发展概况的资料; 对某一个问题研究情况的资料; 对同一问题几种不同观点的资料; 对某一问题研究最新的资料和成果等等。 第三步,将自己在研究中的体会与资料分别加以比较,找出哪些体会在资料中没有或部分没有;哪些体会虽然资料已有,但自己对此有不同看法;哪些体会和资料是基本一致的;哪些体会是在资料基础上的深化和发挥等等。经过几番深思熟虑的思考过程,就容易萌生自己的想法。把这种想法及时捕捉住,再作进一步的思考,选题的目标也就会渐渐明确起来。