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Study on Solution Crystallization of Musk Ketone and Musk Xylene
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作者 曲红梅 周立山 +2 位作者 白鹏 杨志才 余国琮 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第4期548-551,共4页
The ternary phase diagrams of musk ketone, musk xylene and various solvent were obtained by calcu- lations. Moreover, the double saturated lines were found to be curve for the first time. The methods to separate eutec... The ternary phase diagrams of musk ketone, musk xylene and various solvent were obtained by calcu- lations. Moreover, the double saturated lines were found to be curve for the first time. The methods to separate eutectic mixtures of musks by solution crystallization were suggested on the basis of these phase diagrams. A new process was proposed to get musk ketone and musk xylene from the eutectics by adding acetonitrile and heptane in turn, which was verified by experiments. Musk xylene with purity of 97.50% and musk ketone with purity of 98.10% were obtained. 展开更多
关键词 musk ketone musk xylene ternary phase diagram solution crystallization
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Stability of Crystal Growth Face and Dissolution Face in Crystallization from Solution under Microgravity
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作者 ZHUZhen-He LUOLin 等 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第1期117-124,共8页
The stability of the shapes of crystal growth face and dissolution face in a two-dimensional mathematical model of crystal growth from solution under microgravity is studied. It is proved that the stable shapes of cry... The stability of the shapes of crystal growth face and dissolution face in a two-dimensional mathematical model of crystal growth from solution under microgravity is studied. It is proved that the stable shapes of crystal growth face and dissolution face do exist, which are suitably shaped curves with their upper parts inclined backward properly.The stable shapes of crystal growth faces and dissolution faces are calculated for various values of parameters, Ra, Pr and Sc. It is shown that the stronger the convection relative to the diffusion in solution is, the more backward the upperparts of the stable crystal growth face and dissolution face are inclined. The orientation and the shape of dissolution face hardly affect the stable shape of crystal growth face and vice versa. 展开更多
关键词 MICROGRAVITY crystal growth from solution two-dimensional model stability of crystal growth face and dissolution face
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Fractal Interpretation of Ultrasonic Crystallization of Solutions
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作者 Valery Katz Slava Katz 《Journal of Mechanics Engineering and Automation》 2016年第1期53-58,共6页
Experiments were performed on the crystallization of a CuSO4 solution upon the action of the temperature gradient with the forming of mono crystals three wedges crystal system (prisms). We found that the fractal dim... Experiments were performed on the crystallization of a CuSO4 solution upon the action of the temperature gradient with the forming of mono crystals three wedges crystal system (prisms). We found that the fractal dimension of crystals equals 2.45, which is consistent with the literature data. Crystal growth is represented as the N-rd translation of each side of the crystal lattice with its own speed and with relation to the formation of similar structures--fractals. A mathematical model of ultrasonic crystallization of a CuSO4 solution was proposed. The model is based on the combined use of differential transport equations of momentum, mass, energy and sound waves and a method of similarity and dimensional analysis. The calculated formulas for the concentration of Ccr, the equivalent diameter of the formed crystals dcr and the intensity of internal energy source Ф, associated with the interaction of crystals with the hydro mechanical, heat and sound fields were obtained. Fractal interpretation of ultrasonic crystallization of the CuSO4 solution was made. It was found that on the growth of crystal size d^r directly affects translation N, i.e., an increase in the number of sets of crystals of infinitely small size e, correspond to the size of the crystal lattice. In turn, translation of crystals depends on the geometry of the crystallizer and the physical parameters of external force fields, acting on the CuSO4 solution. A connection of results of the mathematical modeling with the results of fractal analysis of the ultrasonic crystallization of solutions was established. 展开更多
关键词 Ultrasonic crystallization of solutions physical and mathematical simulation fractal interpretation.
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Optimum Kinetic Parameters of Mefenamic Acid Crystallization by PBM
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作者 Serap Cesur Cihan Yaylaci 《Journal of Crystallization Process and Technology》 2012年第3期81-95,共15页
Mefenamic acid (MA) is a high-dose, anti-inflammatory, analgesic agent that is widely prescribed for pain related to menstrual disorders. It has some negative properties, such as a high hydrophobicity with a propensit... Mefenamic acid (MA) is a high-dose, anti-inflammatory, analgesic agent that is widely prescribed for pain related to menstrual disorders. It has some negative properties, such as a high hydrophobicity with a propensity to stick to surfaces, and possess great problems during granulation and tableting. Crystallization kinetics was investigated for mefenamic acid. Availability of data on the kinetics of crystal growth is very important for the development and operation of industrial crystallisation processes. The experiments for the measurement of crystal growth kinetics were carried out using the desupersaturation curve technique based on the measurement of the solution concentration versus time in a seeded isothermal batch experiment. To predict the optimum parameters (b, kb, g, kg) for the nucleation and growth kinetics from the desupersaturation curve obtained, the Population Balance Modelling was used and solved by the method of moments. The initial values for the optimisation problem were estimated by using the approach developed by Garside et al. (1982) [1]. 展开更多
关键词 Industrial crystallization REcrystallization Mefenamic Acid Crystal Growth from solutions crystallization in solutions of Macromolecules Computer Modeling Simulation
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实时研究KDP和DKDP晶体生长边界层的分子结构 被引量:1
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作者 于锡铃 尤静林 +7 位作者 王燕 程振翔 王晶晶 周赫田 余昺鲲 张树君 孙大亮 蒋国昌 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期19-,共1页
When the crystal grows from solution,a sharp variated fluid layer of the solute concentration exists against crystal surface.The sharp variated fluid layer is defined the boundary layer in crystal growth.The molecular... When the crystal grows from solution,a sharp variated fluid layer of the solute concentration exists against crystal surface.The sharp variated fluid layer is defined the boundary layer in crystal growth.The molecular structure of the boundary layers plays a key role in crystal composition,morphology,growth rate and crystal growth mechanism.However,owing to the lacking of suitable probe technique,it is difficult to obtain the information of the moving construction of the boundary layers.Here,the laser Raman Microprobe combining with holographic phase contrast interferometric microphotography is used to probe in situ the molecular structure of the boundary layers during the crystal growth processes of KH 2PO 4(KDP) and KD 2PO 4(DKDP).In supersaturations ranging from 1% to 14%,Raman scattering states at the different positions within the boundary layers have been investigated,and compared with the bands of different concentration solutions alone using laser Raman spectroscopy between 600 and 1350cm -1 .The changes in band parameters of the phosphates within the boundary layers of crystal growth are different from those in solution alone.The influence of the solution concentration on the band parameters of anion phosphate within the layers is nonlinear.With increasing supersaturation,the full width at half height of the P=O 2 symmetric stretch band increases.The new 918(938)cm -1 H(D)O P OH(D) asymmetric stretch,1120(DKDP 1200)cm -1 O P O asymmetric stretch,and extremely weak 1210cm -1 P O H in plane deformation bands appear in the characteristic boundary layers.These new bands show that the cations have direct effects on the phosphate group(aggregates).Under the driving of concentration gradient field of supersaturation,the effects of cations cause the changes of O P O bond angle,atomic charge redistribution,and lead to readjust geometry of anion phosphate group and desolvation.The trend of readjust is close to the geometry of the crystal structure unit and the formation of the cations phosphate crystallization unit. 展开更多
关键词 in situ research growth boundary layer molecular structure solution growing crystal
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氨基酸系列改性TGS晶体研究
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作者 苏根博 贺友平 +1 位作者 姚宏志 史子康 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期106-,共1页
TGS (triglycine sulfate) is a pyroelectric crystal material which has an excllent pyroelectricity.The LATGS,a kind of doped TGS crystal,in which L α alanine (LA) substitues for glycine partially and induces an intern... TGS (triglycine sulfate) is a pyroelectric crystal material which has an excllent pyroelectricity.The LATGS,a kind of doped TGS crystal,in which L α alanine (LA) substitues for glycine partially and induces an internal bias in TGS resulting in permanently poled single domain crystal,becomes the comprehensively used pyroelectric material. Based on the study which was about the locked polarization in LATGS,we select many kinds of aminoacids which have a strong polarity group and a unsymmetry atom to dope into TGS crystals.The aninoacids are LB (L asparagine),LL (L lysine),LH (L histidine) and LG (L glutamid acid).The saturated solutions for above four crystals growth are prepared by TGS doped with different aminoacids in water. Transparent crystals up to several centinetres in size have been grown by circling plate method and the reversible rotation rate of the platform with the crystal was about 90 r/min.There was a prefered growth in the b axis direction,with a growth rate of the b axis of about 1.0-1.2mm/day.The concentrations of aminoacids doped in TGS crystals were determined by a liquid chromatography,the concentrations of different aminoacids are about 10 -3 . It shows that the lattice parameters ( a,b and V )of TGS doped with aminoacids are significant longer than that of pure TGS crystal. We conclude that the pyroelectic cofficient,pyroelectric merit and the locked polarization of four TGS crystals,especially,the internal bield ( E b ) of LLTGS is larger than the LATGS,so that the LLTGS crystal is a promising pyroelectrc material for infrared detector. 展开更多
关键词 TGS crystal pyroelectric material crystal growth from solution
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氯酸钠晶体生长动力学的研究
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作者 陈万春 刘道丹 马文漪 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期30-,共1页
Sodium chlorate is a no coloured,no smell and no poisonous transparent crystal with the formula of NaClO 3.Its structure belongs to the cubic( T 23)class and exhibits optical activity.The space group is P 2 13 and the... Sodium chlorate is a no coloured,no smell and no poisonous transparent crystal with the formula of NaClO 3.Its structure belongs to the cubic( T 23)class and exhibits optical activity.The space group is P 2 13 and there are four molecules per cubic unit cell with a =0.6570nm.We chose the crystal as a research system based on two reasons:(1)since the crystal structure belongs to the cubic class,the crystal faces,such as(100),(010),(001)are possessed of homogeneity,it is the suitable system for studying kinetics of crystal growth;(2)since the solubility of the NaClO 3 is higher in the H 2O and the crystal could be grown from low temperature solution,this is a suitable system for studying a influence of gravity on the boundary layer characteristics of the crystal growth under the microgravity condition. 展开更多
关键词 growth kinetics NaClO 3 crystal in situ observation crystal growth from solution growth mechanism
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Phase Diagram, Growth and Optical Property of the LaBWO_6 Crystal 被引量:2
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作者 孙传祥 林州斌 +2 位作者 张莉珍 黄溢声 王国富 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第7期1088-1092,共5页
The phase diagram, growth and optical property of LaBWO6 crystal are reported. LaBWO6 crystal melts congruently at 1078 ℃. Based on the pseudo-ternary phase diagram of LaBWO6-(Li2WO4/LiF) -B203, the LaBWO6 crystals... The phase diagram, growth and optical property of LaBWO6 crystal are reported. LaBWO6 crystal melts congruently at 1078 ℃. Based on the pseudo-ternary phase diagram of LaBWO6-(Li2WO4/LiF) -B203, the LaBWO6 crystals have been firstly grown by the flux method. LaBWO6 crystal crystallizes in the orthorhombic system, space group P222 with a = 4.1, b = 10.31 and c = 21.71 A. LaBWO6 Crystal exhibits high transparency in a range from 327 to 1100 nm. The absorption edge of the crystal in the UV range is at 293 nm. The SHG efficient of LaBWO6 crystal is 0.3 times as large as that of the KDP crystal. 展开更多
关键词 tungstem borate compound crystal growth from solution optical properties
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Growth and Solvent Effects of a Promising Nonlinear Optical Sodium Paranitrophenolate Dihydrate (NO_2-C_H_4-ONa·2H_2O) Single Crystal 被引量:1
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作者 B.Milton Boaz A.Leyo Rajesh +1 位作者 S.Xavier Jesu Raja S.Jerome Das 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期505-508,共4页
Sodium paranitrophenolate dihydrate (NPNa·2H2O) is an excellent semiorganic nonlinear optical (NLO) material, crystallizes both in water and methanol with high degree of transparency. Good optical quality single ... Sodium paranitrophenolate dihydrate (NPNa·2H2O) is an excellent semiorganic nonlinear optical (NLO) material, crystallizes both in water and methanol with high degree of transparency. Good optical quality single crystals of dimension upto 18 mm×6 mm×3 mm are obtained by isothermal solvent evaporation technique. The solubility of the crystal in different solvents was measured gravimetrically. The single crystals of NPNa·2H2O show variation in physical properties and growth rate in different solvents. Methanol or ethanol solution yields crystals of bipyramidal shape with clear morphology. However, methanol grown crystal is exhibiting improved hardness parameters and possesses excellent thermal stability as compared to water grown crystals. The effects of solvent on hardness parameter along with thermal and optical properties of NPNa·2H2O was revealed in this paper. 展开更多
关键词 solution grown crystals Semiorganic NLO material Solvent effect Absorption spectra Hardness parameters
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MORPHOLOGY OF POLYBUTADIENE “SHISH KEBABS”
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作者 徐洋 周恩乐 +1 位作者 余赋生 钱保功 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第1期1-8,共8页
Shish kebab structure of cis-1 , 4-polybutadiene has been obtained by quiescent solution crystallization at suitable temperature. The morphology and growth mechanism of formation of shish kebab structure have been stu... Shish kebab structure of cis-1 , 4-polybutadiene has been obtained by quiescent solution crystallization at suitable temperature. The morphology and growth mechanism of formation of shish kebab structure have been studied in detail.The higher the molecular weight the faster the sample crystallizes. 展开更多
关键词 Morphology of polymers POLYBUTADIENE Shish kebab solution crystallization
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大尺寸KDP晶体生长
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作者 GAO Zhang-shou LI Yi ping +2 位作者 ZENG Hong WANG Sheng lai SUN Xun 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期116-117,共2页
KDP and its deuterated analog DKDP (K (D x H 1- x ) 2PO 4) are the first ch oice materials in the fabrication of optical switcher and frequency converter fo r inertial confinement fusion study.In the past years,the gr... KDP and its deuterated analog DKDP (K (D x H 1- x ) 2PO 4) are the first ch oice materials in the fabrication of optical switcher and frequency converter fo r inertial confinement fusion study.In the past years,the growth technique has b een d eveloped greatly.Large aperture crystals can be grown with various methods,such as,temperature decreasing,solution circular flow,and rapid growth method,which i ntend to reduce the cost of production and satisfy the requirement of ICF.As to rapid growth method,much attention has been paid to solution stability and the K DP crystal qualities of this method which has been proved that high speed can be obtained.LLNL has grown KDP crystal with dimension of 57mm×57mm×55mm,260 kil ogram in 59 days.This method is very different from conventional method for grow ing KDP crystal in three directions uniformly.In addition to the growth of the pyramidal faces,rapid crystallization from supersaturated solution results in si gnificant growth of prismatic faces.Inclusions of growth solution and incorporat ion of metal impurities will occur in the prism sector as prism extends very muc h by this method.Fast growth needs high supersaturation(10%—30%),so the grow th condition,such as ,raw materials,apparatus,temperature lowing proceed should be controlled very strictly.In order to improve the utilization of KDP crystal g rown by point seed method,we developed 4 vessels circular technique on the bas e of 3 vessels circular technique recently. 展开更多
关键词 KDP crystal nonlinear optical crystal rapid growth crystal growth from solution
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块状晶体生长中的输运现象——从数值的非线性分析到工艺的改进
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作者 C.W.Lan (Department of Chemical Engineering National Taiwan University,Taipei,Taiwan 10617) (Tel (Fax):886 2 2363 3917 Email:lan@ruby.che.ntu.edu.tw) 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期8-8,共1页
The quality of substrate crystals is critical to the performance of devices used in electronic and optoelectronic applications.These bulk crystals are mostly grown from the melt or solution,with a well controlled soli... The quality of substrate crystals is critical to the performance of devices used in electronic and optoelectronic applications.These bulk crystals are mostly grown from the melt or solution,with a well controlled solidification or supersaturation,which is affected significantly by the heat and mass flows.Particularly,in the melt growth,the interface kinetics is so fast that the growth is mainly controlled by the transport processes.Hence,the intricate coupling of heat and mass transfer and melt flow strongly influences the grown crystal quality,but its analysis and control is not a trivial task.For most materials,such as semiconductors and oxides,a detailed analysis of the transport processes through experiments is extremely difficult due to the long growth period at high temperature.Therefore,numerical simulation is inevitable.For the past ten years,crystal growth modeling has become one of the most active research fields in materials processing.Indeed,as long as the melt crystal growth of semiconductors remains a mainstay of the microelectronics industry,its modeling continues to be important.In this talk,the role of transport phenomena in bulk crystal growth and their detailed nonlinear analysis are illustrated through our research work over the years.Particular interests will be paid to the zone melting and Bridgman crystal growth.The control of convection and interface shape through external forces,such as rotation,magnetic fields,and vibration will be discussed.Interface instability leading to“pit formation”and interface breakdown due to thermal and solutal flows will also be illustrated. 展开更多
关键词 crystal growth from melt crystal growth from solution mass transport heat transport
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Crystals based on solid solution of Ag_(1-x) Tl_xBr_(1-x) I_x for the manufacturing of IR fibers 被引量:1
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作者 Alexandr Korsakov Liya Zhukova +1 位作者 Dmitrii Salimgareev Vladislav Zhukov 《Chinese Optics Letters》 SCIE EI CAS CSCD 2015年第9期6-8,共3页
For the development of fiber optics for the range from 0.2 to 50.0 μm, one needs light-stable, nonhygroscopic, ductile crystals that would be transparent within this spectral range and have a lack of cleavage, and fr... For the development of fiber optics for the range from 0.2 to 50.0 μm, one needs light-stable, nonhygroscopic, ductile crystals that would be transparent within this spectral range and have a lack of cleavage, and from which the flexible infrared (IR) fibers are extruded. The crystals based on solid solutions of silver and monadic thallium haides meet the conditions listed above. Consequently, by differential thermal and x ray analyses, we study the TIBr-TII phase diagram using the crystals with optimal compositions, which we grow ourselves. We also manu- facture light-stable nanocrystalline IR fibers that are transparent at longer wavelengths compared with AgC1-AgBr fibers. 展开更多
关键词 I_x for the manufacturing of IR fibers Crystals based on solid solution of Ag IR
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The feasibility of coating by cooling crystallization on ibuprofen naked tablets
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作者 Fatima Mameri Ouahiba Koutchoukali +3 位作者 Mohamed Bouhelassa Anne Hartwig Leila Nemdili Joachim Ulrich 《Frontiers of Chemical Science and Engineering》 SCIE EI CAS CSCD 2017年第2期211-219,共9页
Sugar spray coating is a frequently used process in the pharmaceutical industry. However, this process presents the disadvantage to form an amorphous coating around the active ingredient. A crystalline coating formed ... Sugar spray coating is a frequently used process in the pharmaceutical industry. However, this process presents the disadvantage to form an amorphous coating around the active ingredient. A crystalline coating formed on the surface of a tablet is highly desirable. Recently, a new process of coating by cooling crystallization has been developed and applied on bisacodyl pastilles obtained by melt crystallization. In this work, we investigated the feasibility of coating by cooling crystallization on ibuprofen "naked tablets" manufactured by compression. In the first part of this work, the solubility and the metastable zone width have been determined experimentally for the coating solution because they are essential factors for any crystallization process. In the second part, the coating process is investigated on the operating conditions that affect the surface morphology and the crystal growth rate. These experimental conditions include concentration of the coating solution, degree of sub-cooling, agitation speed, retention time, and surface properties of the naked ibuprofen tablets. The results show that naked tablet coating by cooling crystallization is feasible and can be applied in the pharmaceutical industry. 展开更多
关键词 COATING solution crystallization ibuprofen tablets SUCROSE
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Doped GaSe crystals for laser frequency conversion 被引量:2
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作者 Jin Guo Ji-Jiang Xie +8 位作者 Dian-Jun Li Gui-Long Yang Fei Chen Chun-Rui Wang Lai-Ming Zhang Yury M Andreev Konstantin A Kokh Gregory V Lanskii Valery A Svetlichnyi 《Light(Science & Applications)》 SCIE EI CAS CSCD 2015年第1期47-58,共12页
In this review,we introduce the current state of the art of the growth technology of pure,lightly doped,and heavily doped(solid solution)nonlinear gallium selenide(GaSe)crystals that are able to generate broadband emi... In this review,we introduce the current state of the art of the growth technology of pure,lightly doped,and heavily doped(solid solution)nonlinear gallium selenide(GaSe)crystals that are able to generate broadband emission from the near infrared(IR)(0.8 mm)through the mid-and far-IR(terahertz(THz))ranges and further into the millimeter wave(5.64 mm)range.For the first time,we show that appropriate doping is an efficient method controlling a range of the physical properties of GaSe crystals that are responsible for frequency conversion efficiency and exploitation parameters.After appropriate doping,uniform crystals grown by a modified technology with heat field rotation possess up to 3 times lower absorption coefficient in the main transparency window and THz range.Moreover,doping provides the following benefits:raises by up to 5 times the optical damage threshold;almost eliminates two-photon absorption;allows for dispersion control in the THz range independent of the mid-IR dispersion;and enables crystal processing in arbitrary directions due to the strengthened lattice.Finally,doped GaSe demonstrated better usefulness for processing compared with GaSe grown by the conventional technology and up to 15 times higher frequency conversion efficiency. 展开更多
关键词 frequency conversion GASE solid solution crystal THZ
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