201 research outputs found

    Study on prevention of mildew and adsorption of mycotoxin with nano-ZnO and its complexes

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    饲料霉变并由此造成的霉菌毒素污染问题是一个全球性问题,对畜牧生产和 人类健康构成了巨大危害,尽管人们采取了各种防霉措施,但饲料作物在田间、 收割、贮存、加工等诸多环节受到不同程度的霉菌毒素污染。目前,防止饲料霉 变的最有效途径是在饲料中添加防霉剂和毒素吸附剂,高效、低毒、成本低、具 有广谱抗菌和霉菌毒素吸附能力的抗菌剂和吸附剂是今后的主要发展趋势。 本文采用均匀沉淀法,以NaOH和Na2CO3为联合沉淀剂制备了不同尺寸的 纳米氧化锌,考察了焙烧温度对纳米氧化锌尺寸大小的影响。实验结果表明,随 着焙烧温度的提高,生成的纳米氧化锌有烧结团聚现象,尺寸就变大,其中以 300℃焙烧所得...Moldy feed and the resulting mycotoxin contamination problem is a global problem, it has caused great Against to livestock production and human healt h. Though people have been doing many things for mold, the fodder crops are still polluted by mycotoxin in different levels when they are in the field or being reped and storaged. At present, the most effective way to prevent the feed to be moldy...学位:理学硕士院系专业:化学化工学院化学系_物理化学(含化学物理)学号:2052006115197

    知识经济的表现形式探析

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    知识经济不是抽象的、虚幻的经济形态,有其具体的、实实在在的表现形式。在宏观层面、中观层面和微观层面上都可以一一列举知识经济的表现形式。以知识经济的表现形式衡量我国的经济现状,可以看出我国的经济尚不具备转入知识经济新形态的基础和条件。但是,我国充分意识知识经济的挑战及其带来的机遇却是十分必要的

    双对称五对角矩阵逆特征问题

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    主要研究双对称五对角矩阵逆特征问题的可解性.给出了在给定两个互异实数λ,μ和两个n维对称或反对称向量x,y的情况下,构造一个n阶双对称五对角阵A,使得(λ,x),(μ,y)是A的两个特征对的方法.还给出了两个数值例子.国家自然科学基金( 10271099) 资

    債券基金投資知識平台之建立

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    [[abstract]]投資債券基金的收益穩定、流通性高,近年來國人投資該類基金的比例越高,從2008年投資境內債券基金的人數為17K到2013年77K,成長了346.6%。金額由2008年的773G元到2013年1466G元,成長率達89.63%。雖說比例顯著提升,但選擇基金時知識不足。本研究重新分類、整理,歸納對債券基金影響的因素,如殖利率、違約率、經濟發展強弱、匯率強弱等等因素,依這些因素建置以債券基金為知識庫-債券投資推論系統BIKS(Bond Investment Knowledge system),透過BIKS系統以及使用者輸入的狀況,推薦投資者一個較中立、客觀的第三方建議,供投資者做為參考。 為測試BIKS的系統知識的有效性,我們設計出三種實驗情境,並由BIKS系統得出的結果,該結果與專家進行評估跟分析,發現專家大方向的意見與BIKS得出來的結果是一致的,初步的結果認為BIKS的結果有相當高的實用性。[[sponsorship]]中國文化大學[[conferencetype]]國際[[conferencedate]]20150529~20150530[[booktype]]電子版[[conferencelocation]]台北市, 台

    Enrichment of Heavy Metals by Casuarina equisetifolia of Different Stand Ages

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    为认识木麻黄(Casuarina equisetifolia)防护林带重金属消减效应,利用电感耦合等离子体质谱(ICP-MS)测定了福建省平潭国有防护林场林龄分别为5,15,20,30年的木麻黄小枝、细根、凋落物及林地土壤中5种重金属(Cr、Cu、Zn、Cd和Pb)的含量.结果表明:平潭木麻黄林地土壤重金属Cr、Cu、Zn、Pb、Cd含量均低于福建省土壤和福建海岸带土壤的重金属含量背景值,未发现重金属污染;木麻黄Cr、Cd和Zn的平均含量高出普通植物的正常值范围,木麻黄中重金属含量依Zn>Cr>Pb>Cu>Cd顺序降低;木麻黄细根中的重金属含量最高,且细根对重金属的富集系数也最高;木麻黄对Cr、Cu、Zn、Cd的富集系数均大于1;木麻黄细根中Zn、Cu元素含量显著正相关;小枝对Cr、Cd和Pb,细根对Zn的富集系数均与林龄极显著正相关;木麻黄现存生物量中,Cr、Cu、Zn、Cd和Pb的现存储量分别为3.06~3.46 kg/hm2,1.14~1.57kg/hm2,11.67~12.57 kg/hm2,0.05~0.09 kg/hm2和0.45~1.84 kg/hm2,且主要存在于根和树干中;随着林龄的增加,木麻黄积累大量的重金属,并达到其峰值.综上所述,木麻黄防护林在防风固沙的同时,能够吸收富集大量的重金属,对海岸带的重金属污染具有明显的消减作用.Casuarina equisetifolia is the key species in the seashore shelter belt in Fujian Province.It is necessary to assess enrichment of heavy metals by C. equisetifolia.Concentrations of heavy metals,including Cr,Cu,Zn,Cd and Pb,in branchlet,fine root,litter and soil of C.equisetifolia in 4 ages( 5,15,20,30 a) were determined.There was no heavy metal pollution in the shelter belt soil. The results showed that the content of the heavy metals in C. equisetifolia could be ranked from high to low as Zn>Cr>Pb>Cu>Cd.The heavy metal content of the fine root was significantly higher than the other parts,and the concentration coefficient of the fine root was also the highest in C. equisetifolia.There was a significant positive correlation between the content of Zn and Cu in the fine root. The concentration coefficients of Cr,Cd,Pb in branchlet,and the concentration coefficient of Zn in the fine root were significantly correlated with stand age.Existing reserves of Cr,Cu,Zn,Cd and Pb were 3. 06-3. 46 kg / hm2,1. 14-1. 57 kg/hm2,11. 67-12. 57 kg/hm2,0. 05-0. 09 kg/hm2,0. 45-1. 84 kg/hm2. Heavy metals mainly existed in the root and trunk.C. equisetifolia had the capability of accumulating heavy metals during growth,and the potential to reduce heavy metal pollution.国家自然科学基金(41176090);; 国家科技支撑计划(2009BADB2B0302
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