神話0814
辣木树,又称鼓槌树、山葵树,属于辣木树科,为多年生常绿小乔木至大乔木,现已知共有14种,供食用栽培的有印度辣木树和非洲辣木树两种品种。 辣木树原产于非洲东北部和印度北部的次喜玛拉雅山麓、红海沿岸等自然条件极其恶劣的地方。辣木树是2012年来在欧美新兴的一种保健植物(食品),号称高钙、高蛋白质、高纤维、低脂质,并且具有增强体力、治疗贫血、抑制病菌、驱除寄生虫等功效。
馋猫爱鱼鱼
、稀土元素的意义��稀土元素是从比较稀少的矿物中发现的,“土”原指不溶于水的物质,故称稀土。英文Rare Earth Element(简写RE或R)。��稀土家族是来自镧系的15个元素,加上与镧系相关密切的钪和钇共17种元素。它们是:镧、铈、镨、钕、钷、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥、钪、钇。你若想用中文呼唤这个家族的某个成员,不用管那贴在一旁的“金”,直接喊边上的“名”,包你八九不离十。稀土是一个神奇的家族。天然的稀土元素常常是结伴同行,人们必须想方设法才能把它们分离。人类在认知稀土的早期,常常在得到某种稀土元素时,却不知道还有别的“顽皮”的元素隐藏其中,或者无法将不愿分手的伙伴分开。比如“镧”就是在“铈”中发现的,它的名字“La”就是希腊语“隐藏”一词的缩写。 “镨钕”在希腊语中意为“双生子”,“镨钕”是在“镧”中间发现的,而40年以后,它们才得以被分离成两个元素,所以一个就叫“镨”,另一个则取名“钕”。还有,“钐”是在“镨钕”中发现的,“钆”又是在“钐”中发现的……。由于特殊的原子结构,稀土家族的成员非常的活泼,且个个身手不凡,魔力无边。它们与其他元素结合,便可组成品类繁多、功能千变万化、用途各异的新型材料,且性能翻番提高,被称作当代的“工业味精”。如:在超音速飞机中应用含稀土的АЦР1和ЖП207合金,可在400℃以下长期工作,它是现今高温性能最好的合金之一,它的持久强度比一般铝合金可提高1~2倍;钢中加入稀土后,制成的薄料横向冲击韧性提高50%以上,耐腐蚀性能提高60%,而每吨钢只要加稀土300克左右,作用十分显著,真可谓四两拨千斤;稀土添加在酸性纺织染料中,可以提高上染率、调整染料和纤维的亲和力、提高染色牢度、改善纤维的色泽、外观质量及手感柔软度、并可节约染料及减少环境污染和减轻劳动强度等;稀土元素可以提高植物的叶绿素含量、增强光合作用、促进根系的发育和对养分的吸收。还能促进种子萌发、促进幼苗生长,还具有使作物增强抗病、抗寒、抗旱的能力;用稀土钷作热源,可为真空探测和人造卫星提供辅助能量。钷电池可作为导弹制导仪器及钟表的电源,此种电池体积小,能连续使用数年之久。在今天的世界上,无论是航天、航空、军事等高科技领域,还是人们的日常生活用品,无论工业、农牧业、还是化学、生物学、医药,稀土的应用及其作用几乎是无所不在,无所不能。二、稀土元素的组成 (Rare Earth Element)周期系ⅢB族中原子序数为21、39和57~71的17种化学元素的统称。其中原子序数为57~ 71的15种化学元素又统称为镧系元素。稀土元素包括钪、钇、镧、铈、镨、钕、钷、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥。通常把镧、铈、镨、钕、钷、钐、铕称为轻稀土元素;钆、铽、镝、钬、铒、铥、镱、镥、钇称为重稀土元素。稀土元素是历史遗留下来的名称,通常把不溶于水的固体氧化物叫做土,而在18世纪 ,这17种元素都是很稀少的尚未被大量发现,因而得名为稀土元素。现已查明,它们并不稀少,特别是中国的稀土资源十分丰富,有开采价值的储量占世界第一位。从1794年芬兰J加多林从瑞典斯德哥尔摩附近的于特比镇发现钇开始,一直到1947年美国JA马林斯基从铀的裂变产物中分离出钷,共经历150多年。已经发现的稀土矿物有250种以上,最重要的有氟碳铈镧矿[(Ce,La)FCO3]、独居石[CePO4,Th3(PO4)4]、磷钇石(YPO4)、黑稀金矿[(Y,Ce,Ca) (Nb,Ta,Ti)2O6]、硅铍钇矿(Y2FeBe2Si2O10)、褐帘石[(Ca,Ce)2(Al,Fe)3Si3O12]、铈硅石[(Ce,Y,Pr)2Si2O7·H2O]。 周期表中IIIB族钪、钇和镧系元素之总称,包括钪(Sc)、钇(Y)、镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钷(Pm)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Tb)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)。其中钷是人造放射性元素。在自然界中主要矿物有独居石、铈硅石、铈铝石、黑稀金矿和磷酸钇矿。因其天然丰度小,又以氧化物或含氧酸盐矿物共生形式存在,故得名。他们都是很活泼的金属,性质极为相似,常见化合价+3,其水合离子大多有颜色,易形成稳定的配化合物。溶剂萃取和离子交换是目前分离稀土的较好方法。镧、铈、镨、钕等轻稀土金属,由于熔点较低,在电解过程可呈熔融状态在阴极上析出,故一般均采用电解法制取。可用氯化物和氟化物两种盐系,前者以稀土氯化物为原料加入电解槽,后者则以氧化物的形式加入。常用的氯化物体系为KCl-RECl3他们在工农业生产和科研中有广泛的用途,在钢铁、铸铁和合金中加入少量稀土能大大改善性能。用稀土制得的磁性材料其磁性极强,用途广泛。在化学工业中广泛用作催化剂。稀土氧化物是重要的发光材料、激光材料。 稀土元素的制备稀土元素的制备是一个相当复杂的过程,首先利用化学处理从氟碳铈镧矿或独居石中获得稀土氯化物或氧化物的混合物,然后再进行单一稀土元素的分离和提取,方法有:①溶剂萃取法。利用稀土元素在水和有机溶剂中分配的不同 ,将稀土的盐类与有机相及水相多次接触,不断地进行再分配而将它们一一分离,此法具有规模大和连续生产的优点。②离子交换法。利用稀土元素与离子交换剂结合的稳定程度不同将它们一一分离。这是分离某些高纯的稀土元素最有效的方法。此法的缺点是规模小,生产周期长。稀土金属的制备方法有:①金属热还原法。常用钙、锂、钠、镁等金属做还原剂,还原稀土金属的卤化物。②熔盐电解法。可电解稀土卤化物与碱金属、碱土金属卤化物的熔盐。进一步纯制可采用真空熔炼法、真空蒸馏法、电迁移法和区域熔炼法。稀土元素的早期应用只限于混合稀土金属与铁形成合金制打火石,硝酸铈用于浸泡汽油灯纱罩。后来用途大为开拓,在炼钢中用作脱氧剂和脱硫剂,用于铸造球墨铸铁。在玻璃工业中用作抛光粉以及玻璃脱色和玻璃着色,用于制彩色陶瓷器皿。稀土-钴硬磁材料具有高剩磁、高矫顽力等优点 。稀土氧化物用作彩色电视荧光粉、日光灯用三基色荧光粉以及激光材料。稀土氯化物用于制造微球分子筛,用于石油催化裂化的催化剂等。
苹果香蕉最爱
随着经济水平的不断发展,人们的消费、生产方式日趋多样,城市生活垃圾的产生也日益增多。Along with the continuously develop of the economy level, people's consumption,mode of production is gradually diverse, city life garbage of the creation also increases increasingly.在众多的城市生活垃圾处理方法里,生活垃圾堆肥法不失为一个很好的处理方法。Live the garbage fertilizer method and don't lose to a good processing method in numerous city the life the garbage processing method.垃圾堆肥法就是利用微生物的活动将垃圾中的易腐有机质分解,转变为富含有机质和氮、磷、钾等营养元素的有机质肥料。The garbage fertilizer method is the activity that makes use of microorganism the easy 腐 in the garbage the organic quality resolve, changing in to enrich organic quality fertilizer of imply the nourishment chemical elements, such as the machine quality and nitrogen,磷 and potassium...etc..高品质的堆肥是一种良好的有机肥料,也是一种良好的土壤改良剂和调节剂,对土壤理化性质的改良和农作物品质的改善具有积极的意义,在农业生产应用上具有广阔的前景。The high-quality fertilizer is a kind of good organic fertilizer, is also a kind of good soil improver with regulate, have aggressive meaning to the improvement of the soil physics and chemistry property and the improvement of the farm crop quality, produce an application in the agriculture up have vast of foreground.因此,应用堆肥法来处理富含有机质的城市生活垃圾以生产堆肥是城市生活垃圾资源化处理的一个重要方向,是人们研究的一个热点。Therefore, the application fertilizer method to handle to enrich the city life garbage of imply the machine quality with produce fertilizer is an important direction that the city lives the garbage recycling processing, is people research of a is a little bit hot.在本文中,主要介绍了生活垃圾堆肥的关键技术和堆肥的主要成分、养分并对其在农业生产应用中对环境产生的积极影响和负面效应进行了相关的阐述。Mainly introduced the key technique of the living garbage fertilizer and the main composition,nutrient of the fertilizer to combine in this text as to it's in the agriculture the production the application to environment creation of the aggressive influence and negative effect carried on elaborating relatedly.最后,对上述问题提出相应的对策和建议,如改变传统的堆肥方法,与其他生活垃圾处理方法相结合;End, to the above-mentioned problem put forward correspond of counterplan and suggestion, such as change a traditional fertilizer method, with other life garbage processing the method combine together;对土壤中的重金属的防治;To the prevention and cure of the heavy metals in the soil;对堆肥进行深加工,制成高效系列有机-无机复合混肥等。Carry on to the fertilizer to process deeply, make into efficiently series is organic-have no machine compound to mix fatty etc..尽管当前的堆肥理论和技术还不是很完善,但堆肥却很有市场前景,堆肥法应该值得大力普及和推广。Though the current fertilizer theories and technique aren't just very perfect, but the fertilizer have the market foreground very much, the fertilizer method should be worthy of strongly universal with expansion.
为君俏颜
With the level of economic development, people's consumption, production methods are becoming more diverse, MSW has produced the increase. In many urban waste disposal methods, MSW composting is a good approach. Garbage disposal method is the use of microbial activity will refuse the perishable organic matter decomposition into rich in organic matter and nitrogen, phosphorus, potassium and other nutrients, organic fertilizer. High quality compost is a good organic fertilizer, is a good soil conditioner and the regulator, on the physical and chemical properties of soil improvement and the improvement of crop quality with positive implications. the application of agricultural production has bright prospects. Therefore, Application composting method to deal with the organic-rich MSW composting is the production of MSW resources processing a important direction is that people are a hot research. In this paper, mainly on the MSW composting technology and the key to composting of the major components, Nutrient and its application in agricultural production on the environment and the positive impact of the negative effect of the relevant exposition. Finally, the above problems and corresponding countermeasures, such as changes in the traditional composting method, and other waste disposal methods life combined; of the heavy metals in soil control; Composting of deep processing, made a series of high-efficiency organic-inorganic compound fertilizers, and so on. Although the current theory and the composting technology is not perfect, but compost is very good market prospects, composting deserves to be and to popularize.
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