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nacre

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nacre n.1.珠母貝,珍珠母。2.真珠層；真珠質。

n. 1.珠母貝,珍珠母。 2.真珠層；真珠質。 “feldspath nacre“ 中文翻譯：   冰長石同“nacre thickness“ 中文翻譯：   珠層厚度“nacre velvet“ 中文翻譯：   珠光絲絨“moiré nacre“ 中文翻譯：   珠光波紋綢“nacrasa“ 中文翻譯：   刻卡加“nacrae tablet“ 中文翻譯：   (治小兒發育不全及抗癲癇藥) 珠層片“nacred“ 中文翻譯：   adj. 有珍珠層的；似珍珠(質)的。 “nacozari de garcia“ 中文翻譯：   納科薩里德加西亞“nacreddin“ 中文翻譯：   納克爾丁“nacozari“ 中文翻譯：   納科札里“nacrelli“ 中文翻譯：   納克雷利“nacoyo“ 中文翻譯：   納科約

nacred

Application as widely used all over the world , it is a good substitute for asbestos in construction industry , an ideal filling material for paint , dope , rubber and plastic , and its application goes as far as to manyother fields like electric welding , fire retardant , electronic products , oil well drilling and nacre dye 經加工成云母粉還有較好地滑動性和較強的附著力。由于云母和云母粉本身的性能，主要有如下用途：日用化工原料云母陶瓷原料油漆添料塑料和橡膠添料建筑材料用于焊條藥皮的保護層用于鉆井泥漿填加劑等。

To avoid the effects of cosmetics and perfume , pearls should be the last thing a woman puts on before going out and the first thing she takes off after returning home . also , pearls are quite soft , so for the longest - lasting pearls choose those with thick nacre that can help them withstand wear over time . the best way to care for pearls is to wear them often because the body s natural oils keep them lustrous 從報導的實例來看，由于珍珠緊貼人的頸部，它的有效成分可以經摩擦進入人體，珍珠對體液分泌有一定吸收能力，皮膚對珍珠中所含藥物成分也有吸收，乃至影響局部患處，起消炎治療作用至于能治療神經衰弱癥，是因為珍珠具有鎮驚安神作用，但珍珠項鏈如何起安神作用還值得具體研究。

Based on these results , main attentions are paid to the microstructure of nacre according to the study of x - ray diffraction m scanning electron microscopy , transmission electron microscopy and micro - raman spectra , and attentions also to the organic matrix especially the carotenoids in nacre according to in situ study of resonance raman spectra 在此基礎上，重點采用x -射線衍射、掃描電子顯微鏡、透射電子顯微鏡及顯微拉曼光譜等對珍珠層的微結構進行了較詳細的研究，同時采用拉曼光譜對珍珠層中的有機質特征進行了原位分析研究。

In this paper , the nacre of hyriopsis cumingii ( lea ) which is one of the main freshwater pearl - forming mollusk in china is studied emphatically , as compared with the nacre of three species of saltwater pearl - forming mollusks , pinctada martensii ( dunker ) , pinctada maxima ( jameson , and peteria penguin ( roding ) . the basic characteristics of nacreous and prismatic layers are understood by powder x - ray diffraction analysis , trace elements analysis , amino acid composition of protein and differential thermal analysis 本文以我國主要育珠蚌淡水三角帆蚌貝殼珍珠層為重點研究對象，以三種海水育珠貝馬氏珍珠貝、企鵝珍珠貝及大珠母貝貝殼珍珠層為對比研究對象，首先通過粉末x -射線衍射、微量元素分析、蛋白質氨基酸分析及差熱分析對珍珠層及其與之密切共生的棱柱層的基本特征進行了初步研究。

Main conclusions of this work are drawn as follows : 1 ) in nacre of hyriopsis cumingii ( lea ) shell , the aragonite crystallites exist two kinds of orientation , one . which is generally accepted , is the c axis of aragonite perpendicular to nacreous layers , the second , which is proposed in this paper , is the [ 012 ] axis of aragonite perpendicular to nacreous layers 本文所獲得的主要成果有： 1 )明確提出三角帆蚌珍珠層中文石晶體的擇優取向除了存在公認的其c軸垂直珍珠層面外，還存在其[ 012 ]軸垂直珍珠層面的新取向。

3 ) in shell of hyriopsis cumingii ( lea ) , the prismatic layers and the nacreous layers are all composed of aragonite minerals , and aragonite crystallites in prismatic layers show obviously preferential orientation of [ 012 ] axis perpendicular to the shell layers , so it is considered that the orientation of aragonite crystallites in prismatic layers perhaps play an important role in deciding the orientation of aragonite crystallites in nacre and acts as one of template to resulting the formation of aragonite with [ 012 ] orientation perpendicular to nacreous layers in nacre 3 )與海水貝殼明顯不同的是，三角帆蚌棱柱層礦物相與珍珠層一樣皆為文石相，同時查明棱柱層中文石晶體具[ 012 ]軸垂直殼層面的明顯的擇優取向。本文認為，三角帆蚌棱柱層中文石晶體的擇優取向可能對珍珠層中文石晶體的擇優取向存在模板導向的作用，導致珍珠層[ 012 ]定向的文石晶體的形成。

B . main use : as widely used all over the world , it is a good substitute for asbestos in construction industry , an ideal filling material for paint , dope , rubber and plastic , and its application goes as far as to many other fields like electric welding , fire retardant , electronic products , oil well drilling and nacre dye 天然云母粉廣泛應用于絕緣絕熱油漆塑料橡膠陶瓷石油鉆井電焊條化妝品宇航等領域中，超細云母粉作塑料涂料油漆橡膠等功能性填料，可提高其機械強度，增強韌性附著力抗老化及耐腐蝕型等。

And also , these two crystal orientations varying with the different positions in the same nacre of shells clearly shows the structurally inhomogeneities of nacre . these results offer new insight into the study of the nacre formation 對同一三角帆蚌貝殼珍珠層，文石晶體的這兩種擇優取向的程度隨殼結構位置的變化而變化，反映了三角帆蚌珍珠層結構的不均勻性，為研究珍珠層的成因提供了新的思路。

The experiments show that nacre , a type of natural nano - bioceramic material , when used as bone implant for reconstruction of bone defects , is not only biocompatible and biodegradable , but also osteoconductive and osteoinductive 本文根據國外文獻有關利用珍珠層作為骨植入材料的研究報道，就珍珠層的生物相容性和可降解性，及其所具有的骨誘導和骨傳導作用的動物臨床實驗結果，進行了綜合分析和論述。

This suggestion not only provides new scientific evidence for the nacre used as pharmaceutical and hygienical products , but also is of significance to the bleaching of pearl so as to increase the quality and the commercial value of pearls 該研究成果為擴大珍珠及珍珠層在藥用及保健品等領域的應用提供了科學依據，并對珍珠的漂白進而提高其商業價值具有重要的現實意義。

Finally , the effects of carotenoids in nacres or pearls on their commercial value , and the formation mechanism of nacres are discussed preliminarily in terms of the previous works and the results done in this paper 最后在總結前人及本文工作資料的基礎上，對珍珠及珍珠層中類胡蘿卜素的存在對珍珠(層)價值和質量的影響及珍珠層的形成過程兩個問題進行了初步探討。

Compare a 5mm freshwater cultured pearl with a 10mm south sea cultured pearl and the difference in the amount of nacre is obvious . the difference in luster is as clearly visible as the difference in the pearl sizes 所以當光線照射到珍珠上以后，一部分被表面反射，而另一部分則進入珍珠內部，被另一層珍珠層反射，當然，還會有一部分再進入到更深的珍珠層。

Nacre is one of the general construction units of mollusk shells , thoroughly studying on it can provide insight not only into the pearl - culture , but also into fabrication of advanced organic - inorganic composite materials 珍珠層是軟體動物硬殼中普遍發育的一種結構單元，對其進行深入研究可為人工培育珍珠及制造現代有機-無機復合材料提供科學依據。

3 aa very round ( less than 5 % gradation ) ; good luster , good nacre ( . 35 of total nacre or better ) ; 80 - 90 % inclusion free surface ; good / excellent matching ; top 20 % of a pearl farm ' s harvest 3 aa非常圓（少于5 %的那部份的等級） ，良好的光澤，良好的珠層（ 0 . 35或以上的珠層含量） ， 80 % - 90 %的表皮光潔度，好/極好的匹配，珠農收成中最好的20 %部份。

2 ) the carotenoids successfully probed in nacre by in situ resonance raman spectra , are considered one of the most important factors responsible for the coloration of nacre and pearl 2 )采用共振拉曼光譜首次成功地原位探測到三角帆蚌及馬氏珍珠貝珍珠層中類胡蘿卜素的存在，并提出類胡蘿卜素是珍珠層致色的重要原因之一。

The quality of pearls is judged by the orient , which is the soft iridescence caused by the refraction of light by the layers of nacre , and lustre , the reflectivity and shine of the surface 珍珠的價值主要由它的光澤顏色大小有無表面的缺陷和形狀來決定的，其中光澤為最重要的因素。其特有的光澤是光

1 aaa perfect round ; excellent luster ; thick nacre ( . 7 of total nacre or better ) ; 95 % inclusion free surface or better ; excellent matching ; top 1 % of a pearl farm ' s harvest 1 aaa圓度極高，極好的光澤，厚的珠層（ 0 . 7或以上的珠層含量） ， 95 %的表皮光潔度或更高，極好的匹配，珠農收成中最好的1 %部份。

2 aa + perfect round ; excellent luster ; thick nacre ( . 5 of total nacre or better ) ; 90 - 95 % inclusion free surface ; excellent matching ; top 5 % of a pearl farm ' s harvest 圓度極高，極好的光澤，厚的珠層（ 0 . 5或以上的珠層含量） ， 90 - 95 %的表皮光潔度，極好的匹配，珠農收成中最好的5 %部份。

As an oyster creates a pearl , the layers of nacre do not always adhere smoothly . sometimes spots and bubbles can appear in the layering process 由于光的反射，使珍珠看起來明亮有光澤由于光線的透射，使珍珠看起來晶瑩剔透由于折射，光線會生產干涉現象，從而產生了變幻不定的色彩。