查询词典 polytype

The formation mechanism of the screw structures on the surfaces of polytype crystals is discussed according to the theoretical model of anionic coordination polyhedron growth units.

本文用负离子配位多面体生长基元理论模型讨论了多型性晶体表面螺旋结构的形成，提出在多型性晶体中配位多面体呈层状分布，配位多面体的面为层的边界，上、下层负离子配位多面体不是呈镜象对称的，在三方晶系和六方晶系的晶体中是沿晶轴a、b错开，上、下两层负离子配位多面体体呈交叉对应，从而达到稳定平衡。

XRD results sho wed that the fabricated Si-SiC composites were composed of α-SiC,β- SiC an d Si. The polytype of SiC was related to the reaction-heat during the sintering .

XRD结果表明Si-SiC复相陶瓷的主晶相为α-SiC，β-SiC和游离Si，不同晶型SiC的出现与试样烧结过程中Si/C反应的放热过程有关。

The experimental results show that the content of SiC in RBSC increases with carbon content while α-SiC is chosen as a filler. However, the residual carbon would appear in specimens when the carbon content exceeds 30% by weight. Using carbon felt, the reaction-formed SiC particles are small and uniform in size and distribution. However, when carbon felt is impregnated with phenol resin, the reaction-formed SiC is nonuniform in size and distribution. X-ray diffraction shows that the fabricated RBSC is composed of α-SiC,β-SiC, and free Si. The polytype of SiC is related to the reaction-heat during sintering.

结果表明：选用α-SiC+C粉的混合物作为生坯，SiC相的体积分数随生坯中wC的增加而增加，但过大的wC将使硅化后的试样出现残碳；选用碳毡作为生坯，反应烧结碳化硅的显微组织特点是C／Si反应生成的碳化硅颗粒均匀细小，并呈线状分布在游离硅中；浸渍过树脂的碳毡硅化处理后的显微组织特点是反应生成的碳化硅颗粒粗大且呈不均匀分布。X射线衍射结果也表明，反应烧结碳化硅陶瓷由游离Si、α-SiC、β-SiC组成，试样中不同晶型碳化硅的出现与C／Si反应的放热过程有关。

Key words: SiC monocrystals;temperature gradient;growth rate;polytype;enlarged growth

作者简介：李现祥（1977－），男，博士研究生，研究方向：半导体材料。

In-situ formation fibrous polytype AIN composite ceramic material was prepared from AlN-Y_2O_3-SiO_2 system. In comparison with AlN ceramics, both bending strength and fracture toughness of the composite material are much bettered.

本文采用AlN-Y_2O_3-SiO_2，系制备出原位生长纤维状AlN多型体陶瓷复合材料，对其显微结构和生长机制进行了观察和研究，并测量其力学性能。

It indicates that the different parts of the cattle-egg stone samples in different colours all mainly compose of pyrophyllite, coexisted by two kinds of polytype of monoclinic and triclinic pyrophyllite, and the average crystal structural formula is Al4.04 Si7.89 Al0.11O204. The aggregation of pyrophyllite arranges with no direction, and the crystal size of the single pyrophyllite crystal in the weathering skin is a little bigger than that in the basal part.

结果表明，不同颜色牛蛋石样品的不同部位皆以叶腊石为主要成分，并以叶腊石的单斜和三斜两种多型共存，其平均晶体结构化学式为Al4.04[Si7.89Al0.11O20]4；其叶腊石集合体呈无定向排列，风化皮中叶腊石单晶的粒度略大于基体中的。

In the biotechnology area, we has set up polytype Handson yeast express system which owned freedom intellectual property rights, including:(1) URA3 - defective nutrition host cell strain HU-II;(2) secretion and intracellylar expressing plasmid carrier pMPT-01、pMPT-02;(3) a platform for semi-works

在生物技术领域：建立了拥有自主知识产权、较为完善的多型汉逊酵母表达系统，包括：（1）URA3 -营养缺陷型宿主细胞株HU-II；（2）分泌型和胞内型表达质粒载体pMPT-01、pMPT-02；（3）汉逊酵母细胞电穿孔转化操作程序及多拷贝、稳定化整合转化子筛选程序；（4）中试生产规模的发酵和纯化平台。

It is found that there is a mineral association, micro-crystal muscovite and phengite, in this deposit. The mineral assemblage contains about 80% micro-crystal muscovite and about 20% phengite. Their crystallinity is very high and their polytype is 2M1. Both of them are dioctahedral because the d and b of micro-crystal muscovite and phengite are 0.1502 nm, 0.9012 nm and 0.1505 nm, 0.9030 nm, respectively. For their d and b are larger than those of common muscovite, the reason why Fe(superscript 2+)+Fe(superscript 3+) and Mg(superscript 2+) are high in the ore is that Al(superscript 3+) in the octahedron is replaced by Fe(superscript 2+)+Fe(superscript 3+) and Mg(superscript 2+), and this is a phengite series mineral association formed through isomorphic replacement.

该矿物组合中的微晶白云母和多硅白云母结晶度高，多型为2M1，其含量分别为80%和20%左右；二者都属二八面体型白云母类矿物，但d060和b值偏大，微晶白云母的d060=0.1502nm，b=0.9012nm，多硅白云母的d060=0.1505nm，b=0.9030nm；微晶白云母矿铝含量较低、铁镁含量较高，其原因是白云母晶体铝氧八面体中的Al离子被Fe、Mg等离子所取代，这一矿物组合是通过矿物类质同象作用所形成一种多硅白云母系列矿物。

Keywords: wagnerite new polytype; prismatine; volatile; sillimanite; Larsemann Hills

中文关键词：氟磷镁石新多型；柱晶石；挥发分；夕线石；南极拉斯曼丘陵

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。