Crystal Engineering最新文献

Crystallographic patterns in nature and Turkish art 自然界和土耳其艺术中的晶体图案

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2004.03.001

Hacali Necefoglu

{"title":"Crystallographic patterns in nature and Turkish art","authors":"Hacali Necefoglu","doi":"10.1016/j.cryseng.2004.03.001","DOIUrl":"10.1016/j.cryseng.2004.03.001","url":null,"abstract":"<div>In this paper, crystallographic aspects of ancient, medieval and modern Turkish ornaments are dealt with. Crystallographic patterns (CPs) are considerably different from other patterns. The following are characteristic of CPs: the edge of ornament elements draws the edge of the figure; maximal compactness of the ornament elements; lack of background or transformation of background to ornament elements; minimization of the variety of ornament elements; symmetry is not used for form creation. In the process of the construction of CPs, symmetry appears as a result of combination, not as a means of its formation that is characteristic of other ornaments. Their symmetries are analogous to symmetries of natural objects. The atoms and molecules dispose themselves in crystals just as elements arrange themselves in CPs. In other words, CPs are constructed according to the same principles of crystal formation, i.e. the principle of tight packing. The similarity (isomorphism) of crystals and ornaments enables us to describe the ornaments with structural analysis terms, and the similarity between ornaments and crystal structures can be also used in chemistry education. This will bring an aesthetical aspect to education. An invisible part of nature can be studied as ornament creation. Each newly created CP is the structural scheme of a number of possible compounds. The familiarity with such ornaments and the ability to create them are important for solving compound structures. Similarity of patterns with some crystal structures enables us to reach the following conclusions: mankind may make use of the principles from which nature was created, and he may achieve a resemblance to the creation of nature in ideal; mankind may create nothing whose prototype does not exist in nature.</div>","PeriodicalId":10766,"journal":{"name":"Crystal Engineering","volume":"6 4","pages":"Pages 153-166"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cryseng.2004.03.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78833001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Number patterns in Nature 自然界中的数字模式

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2003.11.004

Jan C.A. Boeyens

引用次数: 8

Raman analysis of red-brown and gray shards from 16th and 17th century Portuguese shipwrecks 对16和17世纪葡萄牙沉船上的红棕色和灰色碎片进行拉曼分析

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2004.04.005

M.A. Legodi, D. de Waal

{"title":"Raman analysis of red-brown and gray shards from 16th and 17th century Portuguese shipwrecks","authors":"M.A. Legodi, D. de Waal","doi":"10.1016/j.cryseng.2004.04.005","DOIUrl":"10.1016/j.cryseng.2004.04.005","url":null,"abstract":"<div>The artifacts under investigation (three red clay shards, two gray clay shards and a red clay teapot) are from the J A Van Tilburg museum at the University of Pretoria (UP). The large red clay shard was recovered from the 1552 Portuguese shipwreck, São João, found in the region of Port Edward, South Africa. The other shards were recovered from the 1622 Portuguese shipwreck, the São João Baptista, which sank around Kenton-on-sea off the South African coast. The results from these are compared to those obtained from the analysis of a red-brown teapot. The oldest of this type of teapot was made in China during the second half of the 18th century. Raman spectroscopy has proven to be a useful tool for qualitative determination of the composition of these clay artifacts. The red clays were characterized by the presence of hematite, kaolin, quartz, amorphous carbon and aluminosilicates. The results of the clay teapot differed from those of red clay shards in that no quartz Raman bands were observed for the clay teapot. The gray clay shards were characterized mainly by the presence of quartz, kaolin, amorphous carbon and aluminosilicates. The presence of mullite in all samples could not be ascertained unambiguously using Raman spectroscopy. The pigments found in the investigated samples are hematite (α-Fe2O3) (for red samples) and amorphous carbon (for both red and gray samples).</div>","PeriodicalId":10766,"journal":{"name":"Crystal Engineering","volume":"6 4","pages":"Pages 287-299"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cryseng.2004.04.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75031458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Number patterns in crystallography 晶体学中的数字模式

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2004.04.003

John S. Rutherford

引用次数: 0

High-pressure-induced structural changes in molecular crystals preserving the space group symmetry: anisotropic distortion/isosymmetric polymorphism 保持空间群对称性的高压诱导分子晶体结构变化:各向异性畸变/等对称多态

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2003.11.005

Elena V. Boldyreva

引用次数: 89

Crystallographic excursion in superspace 超空间中的晶体偏移

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2004.04.001

Gervais Chapuis

{"title":"Crystallographic excursion in superspace","authors":"Gervais Chapuis","doi":"10.1016/j.cryseng.2004.04.001","DOIUrl":"10.1016/j.cryseng.2004.04.001","url":null,"abstract":"<div>After studying more than 100 different samples of calaverite Au1-pAgpTe2 (p < 0.15) three famous mineralogists declared in a well documented 1931 publication the invalidity of the law of rational indices. What could lead them to draw such an extreme conclusion from the observation law of Hauÿ dating from more than two centuries? Their observations remained unexplained for the next forty years. In the 1970's, the room temperature structure of γ-Na2CO3 resisted any attempt for a precise structural analysis. The appearance of satellite reflections was noted on single crystal diffractograms which led to the generalisation of the concept of crystal. This generalisation consisted in using at least four integers to fully characterise each individual diffractions peaks. The theory of periodic crystals in space of higher dimension, i.e. the superspace was then developed to deal with the new experimental observations. Later, a new class of materials called composite crystals and still later, the discovery of quasicrystals only reinforced the validity of the superspace concept to describe any material requiring more than three integers to index their diffraction pattern.What is the essence of superspace to describe crystalline structures? Any crystal structure requesting more than three integers to index its diffraction pattern can be described as a periodic object in superspace with dimension equal to the number of required integer. The structure observed in our real word is a three dimensional cut of the superspace description. In general this cut is irrational and consequently the crystal is aperiodic. Calaverite and γ-Na2CO3 are examples of aperiodic crystals which includes incommensurately modulated crystals, composite and quasi-crystals. Rational cuts are also possible. In this case, the structure is periodic and is usually called a superstructure.</div>","PeriodicalId":10766,"journal":{"name":"Crystal Engineering","volume":"6 4","pages":"Pages 187-195"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cryseng.2004.04.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73962278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

The Mirror of Galadriel: looking at chiral and achiral crystal structures 凯兰崔尔之镜:观察手性和非手性晶体结构

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2003.10.001

H.D. Flack, G. Bernardinelli

引用次数: 24

Structure correlation in bispidine coordination compounds—isomerism and tuneable reactivity 比必定配位化合物的结构相关性——同分异构和可调反应性

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2004.04.002

Peter Comba, Marion Kerscher

引用次数: 15

Aspects of breaking of symmetry through vibrational motions 通过振动运动打破对称性的方面

Crystal Engineering Pub Date : 2003-12-01 DOI: 10.1016/j.cryseng.2004.02.002

J.F. Ogilvie