期刊文献+
共找到28篇文章
< 1 2 >
每页显示 20 50 100
Analytical solution of crystal diffraction intensity
1
作者 Wan-Li Shang Ao Sun +13 位作者 Hua-Bin Du Guo-Hong Yang Min-Xi Wei Xu-Fei Xie Xing-Sen Che Li-Fei Hou Wen-Hai Zhang Miao Li Jun Shi Feng Wang Hai-En He Jia-Min Yang Shao-En Jiang Bao-Han Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第11期430-433,共4页
Plasma density and temperature can be diagnosed by x-ray line emission measurement with crystal,and bent crystals such as von Hamos and Hall structures are proposed to improve the diffraction brightness.In this study,... Plasma density and temperature can be diagnosed by x-ray line emission measurement with crystal,and bent crystals such as von Hamos and Hall structures are proposed to improve the diffraction brightness.In this study,a straightforward solution for the focusing schemes of flat and bent crystals is provided.Simulations with XOP code are performed to validate the analytical model,and good agreements are achieved.The von Hamos or multi-cone crystal can lead to several hundred times intensity enhancements for a 200μm plasma source.This model benefits the applications of the focusing bent crystals. 展开更多
关键词 crystal diffraction analytic method x-ray diffraction
原文传递
Improvement of Lattice Parameter Accuracy in Single Crystal XRD Based on a Laser-Induced X-Ray Source
2
作者 LIU Jin WANG Qiannan LI Jiangtao 《高压物理学报》 北大核心 2025年第4期9-15,共7页
The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more... The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for materials.We propose an iterative method for obtaining more precise lattice parameters using the interaction points for the pseudo-Kossel pattern obtained from laser-induced X-ray diffraction(XRD).This method has been validated by the analysis of an XRD experiment conducted on iron single crystals.Furthermore,the method was used to calculate the compression ratio and rotated angle of an LiF sample under high pressure loading.This technique provides a robust tool for in-situ characterization of structural changes in single crystals under extreme conditions.It has significant implications for studying the equation of state and phase transitions. 展开更多
关键词 lattice parameter measurement accuracy single crystal X-ray diffraction iterative algorithm high pressure ratio of compression
在线阅读 下载PDF
Comparison between Double Crystals X-ray Diffraction and Micro-Raman Measurement on Composition Determination of High Ge Content Si_(1-x)Ge_(x) Layer Epitaxied on Si Substrate 被引量:1
3
作者 Lei ZHAO Yuhua ZUO Buwen CHENG Jinzhong YU Qiming WANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第5期651-654,共4页
It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction (DCXRD) and mi... It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction (DCXRD) and micro-Raman measurement, were introduced comparatively to determine x value in Si1-xGex layer, which show that while the two methods are consistent with each other when x is low, the results obtained from double crystals X-ray diffraction are not credible due to the large strain relaxation occurring in Si1-xGex layers when Ge content is higher than about 20%. Micro-Raman measurement is more appropriate for determining high Ge content than DCXRD. 展开更多
关键词 Si1-xGex Ge content Composition determination Double crystals X-ray diffraction (DCXRD) Micro-Raman measurement
在线阅读 下载PDF
Synthesis and Crystal Structures of Schiff Bases Bearing Ferrocenylphenyl Groups
4
作者 YanXU YongFU MaoPingSONG YangJieWU 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第7期863-866,共4页
The Schiff bases bearing ferrocenylphenyl and diferrocenylphenyl groups were synthesized by the reactions of m-ferrocenylaniline with salicylaldehyde or 1, 4-bis (2′-formyl- phenyl)-1, 4-dioxabutane. The title compou... The Schiff bases bearing ferrocenylphenyl and diferrocenylphenyl groups were synthesized by the reactions of m-ferrocenylaniline with salicylaldehyde or 1, 4-bis (2′-formyl- phenyl)-1, 4-dioxabutane. The title compounds were characterized by elemental analysis, IR, 1H NMR and X-ray structural determination. 展开更多
关键词 FERROCENE Schiff base single crystal diffraction synthesis.
在线阅读 下载PDF
Crystal Type Iof Azilsartan Polymorphs: Preparation and Analysis
5
作者 Yuhua Ge Tingting Li Jingjing Cheng 《Journal of Crystallization Process and Technology》 2016年第1期1-10,共10页
Azilsartan (2-ethoxy-1-([2’-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl)-1H-benzimidazole-7-carboxylic acid) is a new angiotensin II receptor antagonist used in the treatment of hypertension. This pa... Azilsartan (2-ethoxy-1-([2’-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl)-1H-benzimidazole-7-carboxylic acid) is a new angiotensin II receptor antagonist used in the treatment of hypertension. This paper describes the preparation of type I crystal and its single crystal diffraction data, the comparison of the powder diffraction data for both type I and II crystals as well as their stability and solubility in methanol. 展开更多
关键词 Azilsartan Single crystal diffraction Powder diffraction SOLUBILITY STABILITY
在线阅读 下载PDF
Growth and characterizations of CdGeAs2single crystal by descending crucible with rotation method 被引量:5
6
作者 Wei Huang Bei-Jun Zhao +4 位作者 Shi-Fu Zhu Zhi-Yu He Bao-Jun Chen Jing-Jing Tang Wei-Jia Liu 《Rare Metals》 SCIE EI CAS CSCD 2014年第2期210-214,共5页
By the method of descending crucible with rotation, crack-free CdGeAs2single crystals of U15 mm 950 mm were grown in a furnace with three independen heating zones after optimizing the temperature field, and the descen... By the method of descending crucible with rotation, crack-free CdGeAs2single crystals of U15 mm 950 mm were grown in a furnace with three independen heating zones after optimizing the temperature field, and the descending and rotational speed to meet the need of CdGeAs2crystal growth. The properties of as-grown crysta were characterized by a variety of techniques. The results of X-ray diffraction(XRD) show that there are two cleavage faces, which are(110) and(101). The peaks are in high intensity and good symmetry, which demonstrates that the crystal is integral in structure and well crystallized. The energy-dispersive spectrometry results indicate that the wafer of the CdGeAs2crystal is closer to the stoichiometry The IR transmittance of the wafer is *48.6 % at 5.5 lm, and the maximum value is up to 51.6 % in the range of2.3–18.0 lm. Etch pits of(001) face are observed and the density of the etch pits is evaluated to be 1 9 105cm-2. 展开更多
关键词 CdGeAs2 crystal crystal growth X-ray diffraction IR transmittance
原文传递
Solvent-free Synthesis and Crystal Structure of 2,2'-Dialkyl Bis(3-methyl-6,7- dihydrobenzofuran-4(5H)-one) Derivatives 被引量:1
7
作者 丁泽鉴 张锋 +3 位作者 徐天笑 王文彬 金蕾 黄年玉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第7期1124-1129,共6页
A series of 2,2'-dialkyl bis(3-methyl-6,7-dihydrobenzofuran-4(5H)-one) derivatives was prepared through H2SO4·SiO2 catalyzed condensation reaction under solvent-free conditions as potential anti-tumor agents... A series of 2,2'-dialkyl bis(3-methyl-6,7-dihydrobenzofuran-4(5H)-one) derivatives was prepared through H2SO4·SiO2 catalyzed condensation reaction under solvent-free conditions as potential anti-tumor agents. All of them were characterized by ESI-MS, IR and NMR spectra. Meanwhile, the single crystal of the target compound (4b), C24H28O4, was also obtained and determined by X-ray crystallography. Crystal data: triclinic system, space group P , a = 8.463(10), b = 9.612(11), c = 13.828(15) , α = 74.29(5), β = 80.93(5), γ = 69.90(3)°, V = 1014(2) 3, Z = 2, F(000) = 408, Dc = 1.246 g/cm3, μ = 0.084 mm?1, R = 0.0883 and wR = 0.2440 for 4616 independent reflections (Rint = 0.1200) and 3490 observed ones (I 〉 2σ(I)). 展开更多
关键词 X-ray diffraction crystal structure bis(2-tetrahydrobenzofuranyl)alkane cytotoxic activity synthesis
在线阅读 下载PDF
Synthesis,Crystal Structure and Cytotoxic Activities of 1-(Prop-2-yn-1-yl)-7,8-dihydro-1H-benzo[d][1,3]-thiazine-2,5(4H,6H)-dione Derivatives 被引量:1
8
作者 王文彬 张凡 +3 位作者 何祥 孟志慧 黄年玉 邹坤 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第4期656-662,共7页
The important synthetic precursor(Ⅲ), 1-(prop-2-yn-1-yl)-7,8-dihydro-1Hbenzo[d][1,3]thiazine-2,5(4H,6H)-dione(C(11)H(11)NO2S), was prepared through a three-component reaction, which was further transferre... The important synthetic precursor(Ⅲ), 1-(prop-2-yn-1-yl)-7,8-dihydro-1Hbenzo[d][1,3]thiazine-2,5(4H,6H)-dione(C(11)H(11)NO2S), was prepared through a three-component reaction, which was further transferred into cytotoxic triazoles by alkylation and "click" synthesis in satisfactory yields of 87%^95%. Their structures were characterized by IR, H-RESI-MS and NMR analysis. Meanwhile, the crystal of Ⅲ was obtained and determined by X-ray single-crystal diffraction. Crystal data: orthorhombic system, space group P212121, a = 5.189(4), b = 8.661(6), c = 23.498(17) A, V = 1056.2(13) A^3, Z = 4, F(000) = 464, Dc = 1.392 g/cm^3, μ =0.284 mm^-1, R = 0.0637 and wR = 0.1668 for 8182 independent reflections(R(int) = 0.1580) and 2166 observed ones(I 〉 2σ(I)). 展开更多
关键词 X-ray diffraction crystal structure 7 8-dihydro-1H-benzo[d][1 3]thiazine-2 5(4H 6H)-dione cytotoxic activity triazole
在线阅读 下载PDF
Synthesis, Characterization and Crystal Structure of Bis[1 -meth oxy-2,2,2-tris-(pyrazol-1 -yl-KN2)ethane]-coppe r(Ⅱ) Bis-perchlorate
9
作者 Ganna Lyubartseva Sean Parkin +1 位作者 Shamiso Ngongoni Uma Prasad Mallik 《Journal of Chemistry and Chemical Engineering》 2016年第5期207-211,共5页
Bis[1-methoxy-2,2,2-tris-(pyrazol-l-yl-KN2)ethane]-copper(Ⅱ) bis-perchlorate (2) was synthesized by reacting of pyrazole based tripodal scorpionate ligand 1-methoxy-2,2,2-tris(pyrazol-1-yl)ethane (1) with c... Bis[1-methoxy-2,2,2-tris-(pyrazol-l-yl-KN2)ethane]-copper(Ⅱ) bis-perchlorate (2) was synthesized by reacting of pyrazole based tripodal scorpionate ligand 1-methoxy-2,2,2-tris(pyrazol-1-yl)ethane (1) with copper(Ⅱ) perchlorate hexahydrate in methanol, acetonitrile and water mixture as solvent. Slow evaporation of the filtered reaction mixture in air produced blue color block crystals suitable for single crystal X-ray diffraction study of the title complex. Compound 2 crystallizes in the monoclinic space group P21/n with unit cell parameters, α = 8.1269(1) ,A, b = 21.8348(2)A, c = 9.1522(1) A, a = γ= 90° , β = 99.7611 (4)°. The structure of the compound was characterized by IR Spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. 展开更多
关键词 PYRAZOLE tripodal ligand scorpionate ligand single crystal X-ray diffraction.
在线阅读 下载PDF
Effects of doping Fe cations on crystal structure and thermal expansion property of Yb_2Mo_3O_(12)
10
作者 Ying-Zhi Cheng Xiu-Yu Sun +3 位作者 Xiao-Ling Xiao Xiang-Feng Liu Li Xue Zhong-Bo Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第7期1600-1606,共7页
Crystal structures and thermal expansion properties of Yb2-xFexMo3O12(x=0.0,0.6,1.0,1.1,1.4) solid solutions have been studied by X-ray powder diffraction(XRPD) at different temperatures.Rietveld analysis of the X... Crystal structures and thermal expansion properties of Yb2-xFexMo3O12(x=0.0,0.6,1.0,1.1,1.4) solid solutions have been studied by X-ray powder diffraction(XRPD) at different temperatures.Rietveld analysis of the XRPD data shows that Yb2-xFexMo3O12 solid solutions adopt orthorhombic structure and have variable thermal expansion coefficients controlled by the ratio of Yb^3+ to Fe^3+.Yb2Mo3O12 shows anisotropic negative thermal expansion property,induced by the reductions in average Yb-O-Mo angle and average apparent Mo2-O bond length with increasing temperatures.As more Yb^3+ substituted by Fe^3+,the linear thermal expansion coefficients of Yb2-xFexMo3O12 increase from negative to positive.A near-zero thermal expansion coefficient of 0.55×10^-6K^-1 for Yb0.6Fe1.4Mo3O12 is observed in the temperature range of 573-873 K. 展开更多
关键词 Negative thermal expansion crystal structure X-ray diffraction Rietveld method Molybdate
原文传递
Asymmetric dynamic phase holographic grating in nematic liquid crystal
11
作者 任常愚 石宏新 +3 位作者 艾延宝 尹向宝 王丰 丁红伟 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期105-109,共5页
A new scheme for recording a dynamic phase grating with an asymmetric profile in C60-doped homeotropically aligned nematic liquid crystal(NLC) was presented.An oblique incidence beam was used to record the thin asym... A new scheme for recording a dynamic phase grating with an asymmetric profile in C60-doped homeotropically aligned nematic liquid crystal(NLC) was presented.An oblique incidence beam was used to record the thin asymmetric dynamic phase holographic grating.The diffraction efficiency we achieved is more than 40%,exceeding the theoretical limit for symmetric profile gratings.Both facts can be explained by assuming that a grating with an asymmetric saw-tooth profile is formed in the NLC.Finally,physical mechanism and mathematical model for characterizing the asymmetric phase holographic grating were presented,based on the photo-refractive-like(PR-like) effect. 展开更多
关键词 nematic liquid crystal asymmetric phase grating diffraction efficiency photorefractive effect
原文传递
Spectroscopic studies of gel-grown lanthanum malonate crystals
12
作者 Varghese Mathew Sabu Jacob +1 位作者 Lizymol Xavier K.E.Abraham 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第3期245-249,共5页
Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectrosco... Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectroscopy (FTIR) and fourier transform (FT) Raman studies confirmed the presence of functional groups in the title compound. The optical band gap energy of the material was extracted from diffuse reflectance spectrum. 展开更多
关键词 lanthanum malonate crystal growth X-ray diffraction analysis DRS studies FTIR and FT Raman studies rare earths
原文传递
Syntheses and Crystal Structures of Pyridyl Substituted Dibenzo[b,e]-[1,4]diazepin-1-one Derivatives
13
作者 汪芳明 鲍丹 +3 位作者 王明 李明峻 陈立庄 韩光范 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第2期179-184,共6页
A new series of 11-pyridyl substituted dibenzo-diazepin-l-one derivatives 1 was synthesized by a two step cyclocondensation reaction. All the compounds were characterized by IR, MS, and H NMR. And crystals of la and l... A new series of 11-pyridyl substituted dibenzo-diazepin-l-one derivatives 1 was synthesized by a two step cyclocondensation reaction. All the compounds were characterized by IR, MS, and H NMR. And crystals of la and lb were obtained and determined by X-ray single-crystal diffraction. Crystal data of la: C48H52N607, monoclinic system, space group C2/c, a = 28.39(4), b = 9.275(12), c = 16.84(2) A, β = 104.98(3)°, V= 4284(10) A3, Z= 4, F(000) = 1752, Dc = 1.279 g/cm3, R = 0.0603, and wR = 0.1314. Crystal data of 1b: C24H21N30, monoclinic system, space group P21/c, a = 11.625(5), b = 19.055(9), c = 8.741(4) A, fl = 95.547(6)°, V= 1927.2(15) A3, Z = 4, F(000) = 776, Dc = 1.266 g/cm3, R = 0.0494, and wR = 0.1287. 展开更多
关键词 X-ray diffraction crystal structure benzodiazepine synthesis
在线阅读 下载PDF
Thiocyanate-controlled Copper(Ⅱ)-L-arginine Complex:Synthesis,Crystal Structure and Characterization
14
作者 范广 邓玲娟 +3 位作者 马占营 李小博 张引莉 孙家娟 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第1期100-106,共7页
A novel thiocyanate-controlled copper(Ⅱ)-L-arginine complex with the formula of Cu(Arg)(SCN)2(1,Arg:L-arginine) has been obtained from aqueous solution and structurally characterized by single-crystal X-ray ... A novel thiocyanate-controlled copper(Ⅱ)-L-arginine complex with the formula of Cu(Arg)(SCN)2(1,Arg:L-arginine) has been obtained from aqueous solution and structurally characterized by single-crystal X-ray diffraction method.Crystal data:orthorhombic,space group P212121,a = 6.0156(5),b = 12.1905(11),c = 18.4203(16) A°,V = 1350.8(2) A°3,Z = 4,μ = 1.933mm^(-1),F(000) = 724,S = 1.084,the final R = 0.0410,wR = 0.0754 for 1893 observed reflections with I 〉 2σ(I),and R = 0.0559,wR = 0.0820 for all reflections.In addition,elemental analysis,IR,TG-DTG and magnetism characterization are presented. 展开更多
关键词 L-arginine copper complex crystal structure single-crystal X-ray diffraction
在线阅读 下载PDF
Synthesis, characterization, spectroscopic and crystallographic investigation of Cobalt(Ⅲ) schiff base complex with two perpendicular diamine coumarin ligands
15
作者 Imen Ketata Lassad Mechi +3 位作者 Taicir Ben Ayed Michal Dusek Vaclav Petricek Rached Ben Hassen 《Open Journal of Inorganic Chemistry》 2012年第2期33-39,共7页
New transition metal complex of Cobalt(III) of the ligand (E)-3-(1-(2-aminoethylimino)ethyl)-4-hydroxy-2H-chromen-2-one, derived from condensation of ethylene diamine with 3-acetyl-4-hydroxy-chromene-2-one have been s... New transition metal complex of Cobalt(III) of the ligand (E)-3-(1-(2-aminoethylimino)ethyl)-4-hydroxy-2H-chromen-2-one, derived from condensation of ethylene diamine with 3-acetyl-4-hydroxy-chromene-2-one have been synthesized by reaction of cobalt(III) salt and the ligand, in amounts equal to metal-ligand molar ratio of 1:2. Both the Schiff base and the complex of Co(III) were characterized by IR, UV-Vis, 1H NMR- and 13C NMR-spectroscopy techniques. Single crystal X-ray diffraction investigation, at low temperature T = 120 K, shows that the cobalt complex is triclinic P-1, a = 10.426(5) ?, b = 11.3234(2) ?, c = 15.729(5) ?, α(°) = 70.102(4), β(°) = 86.049(4), γ(°) = 82.497(4), Z = 2, and its structure consists of isolated [Co(III)(C13H13N2O3)2]+ complex cations with distorted octahedral geometry, ClO-4 counter anions, acetone solvent and water molecules. The crystal cohesion is stabilized by hydrogen bonds between ligands and water molecules, and ionic interactions between complex cations and counter anions. 展开更多
关键词 Hydroxycoumarin Derivative Co^(Ⅲ) Complex ^(1)H NMR UV-VISIBLE Single crystal X-Ray diffraction
在线阅读 下载PDF
Siderochelins with anti-mycobacterial activity from Amycolatopsis sp. LZ149 被引量:1
16
作者 LU Chun-Hua YE Fang-Wen SHEN Yue-Mao 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2015年第1期69-72,共4页
Three new compounds, namely siderochelins D (2), E (3), and F (4), together with one known siderochelin A (1), were isolated from Amycolatopsis sp. LZ149 and elucidated by spectroscopic analyses includinglD- a... Three new compounds, namely siderochelins D (2), E (3), and F (4), together with one known siderochelin A (1), were isolated from Amycolatopsis sp. LZ149 and elucidated by spectroscopic analyses includinglD- and 2D-NMR and X-ray single crystal diffraction. Compounds 1-3 showed antibacterial activity against Mycobacterium smegmatis. 展开更多
关键词 Amvcolatopsis sp. LZ149 Siderochelin Bioassay-guided Mycobacterium smegmatis X-ray single crystal diffraction
原文传递
On the Mechanism of Condensation between 5-Amino-4, 6-dichloro- 2-methylpyrimidine and 1-Acetyl-2-imidazolin-2-one
17
作者 Bin SU Hui LI +1 位作者 Meng Shen CAI Zhong Jun LI 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第3期207-210,共4页
The condensation reaction between 5-amino-4, 6-dichloro-2-methylpyrimidine and 1-acetyl-2-imidazolin-2-one using POCl3 as solvent gave 4, 6-dichloro-2-methyl-5-(1-acetyl-tetra- hydro-imidazo-2-ylidene)-aminopyrimidine... The condensation reaction between 5-amino-4, 6-dichloro-2-methylpyrimidine and 1-acetyl-2-imidazolin-2-one using POCl3 as solvent gave 4, 6-dichloro-2-methyl-5-(1-acetyl-tetra- hydro-imidazo-2-ylidene)-aminopyrimidine predominantly and 4, 6-dichloro-2-methyl-5-{1-[1-(2- oxo-tetrahydro-imidazolyl)]-acetyene}-aminopyrimidine as by-product. No 4, 6-dichloro-2- methyl-5-(1-acetyl-2-imidazolin-2-yl)-aminopyrimidine was found. The result indicated an esterifi- cation-addition-elimination mechanism. 展开更多
关键词 MOXONIDINE X-ray single crystal diffraction GHMBC.
在线阅读 下载PDF
A Reflectron Time-of-Flight Mass Spectrometer with a Nano-Electrospray Ionization Source for Study of Metal Cluster Compounds
18
作者 吴小虎 谢华 +3 位作者 刘志凌 苏海峰 林水潮 唐紫超 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第4期401-406,I0001,共7页
An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-o... An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the "ionization" process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20(PPhpy2)10Cl2](SbF6)4, where PPhpy2=bis(2- pyridyl)phenylphosphine, and [AuaAg2(C)L6](BF4)4, where L=2-(diphenylphosphino)-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds. 展开更多
关键词 Nano-electrospray ionization source Ion transmission and focus system Reflectron time-of-flight mass spectrometer Metal cluster compounds Single crystal X-ray diffraction
在线阅读 下载PDF
New Iboga‑Type Indole Alkaloids from Tabernaemontana divaricata 被引量:1
19
作者 Xiang-Mei Li Xian-Jun Jiang +4 位作者 Guo-Zhu Wei Li-Hua Ren Li-Xia Wang Xue-Lian Cheng Fei Wang 《Natural Products and Bioprospecting》 CAS 2019年第6期425-429,共5页
Two hitherto unknown iboga-type indole alkaloids,namely(3R)-7,19-di-epi-3-methoxytabernoxidine(1)and(3R,19R)-19-hydroxy-3-(2-oxopropyl)voacangine(2),together with eight known alkaloids(3-10),were isolated from the twi... Two hitherto unknown iboga-type indole alkaloids,namely(3R)-7,19-di-epi-3-methoxytabernoxidine(1)and(3R,19R)-19-hydroxy-3-(2-oxopropyl)voacangine(2),together with eight known alkaloids(3-10),were isolated from the twigs and leaves of Tabernaemontana divaricata.Their structures were established on the basis of spectroscopic data interpretation,single crystal X-ray diffraction analysis and circular dichroism spectrum. 展开更多
关键词 Tabernaemontana divaricata Iboga-type indole alkaloid Single crystal X-ray diffraction
在线阅读 下载PDF
Structural, Optical, and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Spray Pyrolysis Technique 被引量:1
20
作者 K.Usharani A. R.Balu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2015年第1期64-71,共8页
Thin films of zinc-doped cadmium oxide with different Zn-doping levels(0, 2, 4, 6, and 8 at%) were deposited on glass substrates by employing an inexpensive, simplified spray technique using perfume atomizer at rela... Thin films of zinc-doped cadmium oxide with different Zn-doping levels(0, 2, 4, 6, and 8 at%) were deposited on glass substrates by employing an inexpensive, simplified spray technique using perfume atomizer at relatively low substrate temperature(375 °C) compared with the conventional spray method. The effect of Zn doping on the structural,morphological, optical, and electrical properties of the films was investigated. XRD patterns revealed that all the films are polycrystalline in nature having cubic crystal structure with a preferential orientation along the(1 1 1) plane irrespective of Zn-doping level. Zn-doping level causes a slight shift in the(1 1 1) diffraction peak toward higher angle. The crystallite size of the films was found to be in the range of 28–37 nm. The band gap value increases with Zn doping and reaches a maximum of 2.65 eV for the film coated with 6 at% Zn doping and for further higher doping concentration it decreases.Electrical studies indicate that Zn doping causes a reduction in the resistivity of the films and a minimum resistivity of15.69 X cm is observed for the film coated with 6 at% Zn. 展开更多
关键词 Semiconductors Thin films crystal structure Optical properties X-ray diffraction
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部