共查询到20条相似文献，搜索用时 62 毫秒
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以SeO2和硫脲为原料,在水热条件下制得了硒微米球;然后以硒微米球为硒源,在乙醇溶剂热条件下,通过溶解-晶化过程,获得了硒微米棒．粉体用X-射线粉末衍射（XRD）和光学显微镜（OM）进行了表征．硒微米棒的平均直径35μm,长度达毫米级．并用结晶学的观点讨论了硒微米棒的生长机制． 相似文献
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《洛阳师范学院学报》2019,(5):24-26
通过在培养基中添加不同浓度的硒来研究硒对杏鲍菇菌丝生长和营养成分的影响.结果显示,硒浓度在50μg/mL时四个品种杏鲍菇菌丝的生长值和维生素C含量、蛋白质含量、多糖的含量均达到最大且高于对照组.硒浓度在50μg/mL时能提高杏鲍菇菌丝的产量和营养物质的产出. 相似文献
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选用花生种子为试材,研究不同浓度的硒对花生苗期生长及脂肪酶活力的影响.结果表明:在硒浓度为0.5 mg.L-1时,硒对花生种子发芽率和发芽势有较好的促进作用;硒浓度为1.0 mg.L-1时,MDA含量较低,叶绿素含量较高;硒浓度为3.0 mg.L-1时,脂肪酶活力较高,有利于花生的生长发育;硒浓度为5.0 mg.L-1时,对花生根长和POD活性有较好的促进作用.综合分析,低浓度硒能提高花生种子的发芽率,增加发芽势和根长,对花生苗期生长有促进作用,但高浓度(6.0 mg.L-1)时对花生种子的萌发和幼苗生长则有明显的抑制作用. 相似文献
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《常熟理工学院学报》2015,(4)
以β-环糊精为模板剂,采用水热法以L-半胱氨酸盐酸盐还原亚硒酸制备出具有枝状结构的微纳米硒,使用SEM、TEM、XRD对产物进行了表征,探讨了模板剂用量、反应温度、反应时间对硒晶生长的影响.研究表明,上述因素对产物的形貌有着显著的影响,实验确定的优化反应条件下制得的枝状微纳米硒形貌规则属于三方相t-Se0,但结晶度不高. 相似文献
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硒蛋白及其生物学功能 总被引：5，自引：0，他引：5
硒蛋白是人及动物必需微量元素硒的主要功能形式。近年对硒蛋白的研究取得了诸多进展，例如，发现了在细胞增殖过程中具重要作用的硒蛋白硫氧还蛋白还原酶；深人研究了硒蛋白 P 的结构、表达调控、生物学功能等；揭示了硒以硒半胱氨酸形式参与构成酶的活性中心，而硒半胱氨酸本身则为生物合成和参入到蛋白质中的第21种氨基酸；在哺乳动物发现的35种硒蛋白中．已有十几种研究得比较清楚。本文就这些硒蛋白的结构、分布等特点及生物学功能方面的研究现状作一简要综述。 相似文献
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大豆叶面喷硒可明显提高籽粒硒含量,以鼓粒期一次喷施亚硒酸钠水溶液效果最佳,籽粒硒含量最高可比对照提高31.71倍。大豆叶面喷硒对植株生长及产量无不良影响。 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献