期刊文献+
共找到109篇文章
< 1 2 6 >
每页显示 20 50 100
Optimization of Synthesis of Spherical Lignosulphonate Resin and Its Structure Characterization 被引量:3
1
作者 范娟 詹怀宇 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第3期407-410,共4页
Calcium lignosulphonate was used to synthesize a spherical lignosulphonate resin in a cheap and non-toxic disperse medium by reversed phase suspension polymerization. The process conditions were optimized by orthog... Calcium lignosulphonate was used to synthesize a spherical lignosulphonate resin in a cheap and non-toxic disperse medium by reversed phase suspension polymerization. The process conditions were optimized by orthogonal experiments. Under .the optxmal conditxons (T=95 ℃, CHCl= 3 mol·L^-1, mHCHO: mCLS=7%, WCLS=50%), globulation took about 20 min and the product was featured with excellent spherical shape, narrow particle size range, 61.20% of water retention capacity, 0.83 mmol·ml^- 1 of total volume exchange capacity and 3.46 mmol·g^- 1 of total exchange capacity. The results of Scanning Electron Micrograph and Scanning Probe Micrograph indicate that spherical lignosulphonate resin has a rugged surface with porous microstructure in the gel skeleton. The average pore size of dry samples was determined to be 10.46 nm. by the BET method. 展开更多
关键词 sphencal lignosulphonate resin process optimization structure characterization
下载PDF
The Effect of Spatial Structure Character of Heat Source on the Ray Path and the Evolution of Wave Energy of Meridional Wave Train
2
作者 徐祥德 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1991年第1期87-98,共12页
This paper studies correlations between the spatial structure character of thermal forcing and deformation and the amplitude of rays of meridional wave train. It is shown that if thermal forcing appears a meridional l... This paper studies correlations between the spatial structure character of thermal forcing and deformation and the amplitude of rays of meridional wave train. It is shown that if thermal forcing appears a meridional linear variation the rays of quasi-stationary planetary wave may propagate along oblique lines and if the meridional variability of heat source has second order term the rays show distinct deformation as a great circular route. Additionally, the inhomogeneous distribution may cause lower frequency oscillations in mid- and low-latitudes. The combination of zonal and meridional wave numbers and distributive character of heat source may form an inverse mechanism of variational trend of generized wave energy, reflecting in some degree the physical process of transition between meridional and zonal flow patterns. 展开更多
关键词 The Effect of Spatial structure character of Heat Source on the Ray Path and the Evolution of Wave Energy of Meridional Wave Train PATH Wave
下载PDF
Effect of Limited Enzymatic Hydrolysis on Structure Characterization of Glycinin
3
作者 Chunhong DUAN Wan SUN +2 位作者 Yunjie LI Yunlong WANG Siyi PAN 《Agricultural Biotechnology》 CAS 2012年第3期52-54,共3页
[ Objective] This study aimed to characterize the structure of soybean glycinin affected by limited enzymatic hydrolysis. [ Method ] The glycinin was limitedly hydrolyzed by alkaline protease; then the SDS-polyacrylam... [ Objective] This study aimed to characterize the structure of soybean glycinin affected by limited enzymatic hydrolysis. [ Method ] The glycinin was limitedly hydrolyzed by alkaline protease; then the SDS-polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (fTIR) and other means were performed to characterize the glyeinin structure changing during the hydrolysis process. [ Result] SDS-PAGE analysis showed that the subunit contem of glycinin significantly decreased after hydrolysis, and acidic subunits were more susceptible to hydrolysis than alkaline subunits. The scanning electron microscopy revealed that the structure of glycinin powder changed greatly after hydrolysis. The I^TIR results showed that the propor- tions of all conformations of glycinin changed greatly during hydrolysis process. In addition, the protein hydrophobicity and sulfhydryl content were also significantly influenced by hydrolysis. [ Conclusion] The enzymatic hydrolysis greatly changed the conformations of glyeinin, and the change was dependent on the degree of hy- drolysis. 展开更多
关键词 GLYCININ Alkaline proteinase HYDROLYSIS structure characterization
下载PDF
Bio-soft matter derived from traditional Chinese medicine:Characterizations of hierarchical structure,assembly mechanism,and beyond
4
作者 Guiya Yang Yue Liu +4 位作者 Yuying Hu Yue Yuan Yunan Qin Quan Li Shuangcheng Ma 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第6期823-839,共17页
Structural and functional explorations on bio-soft matter such as micelles,vesicles,nanoparticles,aggregates or polymers derived from traditional Chinese medicine(TCM)has emerged as a new topic in the field of TCM.The... Structural and functional explorations on bio-soft matter such as micelles,vesicles,nanoparticles,aggregates or polymers derived from traditional Chinese medicine(TCM)has emerged as a new topic in the field of TCM.The discovery of such cross-scaled bio-soft matter may provide a unique perspective for unraveling the new effective material basis of TCM as well as developing innovative medicine and biomaterials.Despite the rapid rise of TCM-derived bio-soft matter,their hierarchical structure and assembly mechanism must be unambiguously probed for a further in-depth understanding of their pharmacological activity.In this review,the current emerged TCM-derived bio-soft matter assembled from either small molecules or macromolecules is introduced,and particularly the unambiguous elucidation of their hierarchical structure and assembly mechanism with combined electron microscopic and spectroscopic techniques is depicted.The pros and cons of each technique are also discussed.The future challenges and perspective of TCM-derived bio-soft matter are outlined,particularly the requirement for their precise in situ structural determination is highlighted. 展开更多
关键词 Electron microscopy SPECTROSCOPY Traditional Chinese medicine Bio-soft matter Structural characterization
下载PDF
Structural characterization of three acidic polysaccharides from Opuntia dillenii Haw.fruits and their protective effect against hydrogen peroxide-induced oxidative stress in Huh-7 cells
5
作者 Rui Liu Fangxin Chu +1 位作者 Zheng Yan Hanqing Chen 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期1929-1942,共14页
Three novel acidic polysaccharide fractions(OFPP-1,OFPP-2,OFPP-3)with different m olecular weights(803.7,555.1 and 414.5 k Da)were isolated from the peeled Opuntia dillenii Haw.fruits by alkali-extraction,graded alcoh... Three novel acidic polysaccharide fractions(OFPP-1,OFPP-2,OFPP-3)with different m olecular weights(803.7,555.1 and 414.5 k Da)were isolated from the peeled Opuntia dillenii Haw.fruits by alkali-extraction,graded alcohol precipitation and column chromatography.Structural analysis indicated that OFPPs were pectic polysaccharides consisting of rhamnose,arabinose and galactose residues.The backbone of OFPP-1 consisted of a repeating unit→6-α-D-Galp A-(1→2)-α-L-Rhap-(1→with T-α-D-Galp A-(1→6)-α-D-Galp A-(1→4)-α-D-Glcp-(1→,T-β-D-Xylp-(1→6)-α-D-Galp A-(1→4)-α-D-Glcp-(1→or T-α-D-Galp A-(1→3)-α-L-Araf-(1→as the side chains.The backbone of OFPP-2 consisted of a disaccharide repeating unit→2)-α-L-Rhap-(1→4)-β-D-Galp A-(1→with T-β-L-Araf-(1→as the branches substituted at the O-4 position of→2,4)-α-LRhap-(1→.Whereas the backbone of OFPP-3 was→2,4)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-β-L-Araf-(1→or→2,4)-α-L-Rhap-(1→2)-α-L-Rhap-(1→4)-β-D-Galp A-(1→,which was branched at the O-4 position of→2,4)-α-L-Rhap-(1→.Moreover,these three polysaccharide fractions could protect Huh-7 cells against H2O2-induced oxidative stress to different extents by decreasing the MDA content and increasing the SOD,CAT,GSH-Px activities and the GSH level in the Huh-7 cells.These results suggest that OFPPs have the potential to be used as natural antioxidants. 展开更多
关键词 Opuntia dillenii Haw.fruits POLYSACCHARIDE Alkali extraction Structural characterization Oxidative stress
下载PDF
Structural characterization and anti-inflammatory activities of novel polysaccharides obtained from Pleurotus eryngii
6
作者 Han Wang Sai Ma +5 位作者 Alfred Mugambi Mariga Qiuhui Hu Qian Xu Anxiang Su Ning Ma Gaoxing Ma 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期3031-3042,共12页
Natural polysaccharides named PEP-0.1-1,PEP-0-1 and PEP-0-2 from edible mushroom species Pleurotus eryngii were obtained in the present study.Results showed that molecular weights of these polysaccharides were 3235,20... Natural polysaccharides named PEP-0.1-1,PEP-0-1 and PEP-0-2 from edible mushroom species Pleurotus eryngii were obtained in the present study.Results showed that molecular weights of these polysaccharides were 3235,2041 and 23933 Da,respectively.Further,structural characterization revealed that PEP-0.1-1 had a→4-α-D-Glcp-1→backbone and contained→4)-α-D-Glcp and→4)-β-D-Glcp reducing end groups.PEP-0-1 backbone contained→4-α-D-Glcp-1→and→6-α-3-O-Me-D-Galp-1→,and the side chains containedα-D-Glcp,β-D-Manp-1→andα-D-Glcp-3→.However,PEP-0-2 backbone consisted of→4-α-DGlcp-1→and→6-α-3-O-Me-D-Galp-(1→6)-α-D-Galp-1→while the side chains containedα-D-Glcp andβ-D-Manp-1→.Biological activity analysis was then carried out and found that all these polysaccharides could significantly suppress the relative mRNA expression of toll-like receptor 4,nitric oxide(NO),tumor necrosis factor-α,interleukin(IL)-1βand IL-6 in lipopolysaccharide(LPS)-induced inflammation of RAW264.7 cells,as well as the over secretion of the above cell cytokines.Moreover,Western blotting analysis revealed that all these purified fractions displayed significant inhibition effects on the expression of c-Jun N-terminal kinases protein induced by LPS in mitogen activated protein kinase pathway,along with the relieving on the inhibition effect of LPS on IκB-αprotein expression.In summary,the information generated by the present study could provide a theoretical basis for the exploration of novel healthy food materials from edible mushroom with antiinflammation activities. 展开更多
关键词 Pleurotus eryngii POLYSACCHARIDES Structural characterization Anti-inflammatory activity
下载PDF
Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review
7
作者 Enning Zhou Qiangqiang Li +2 位作者 Dan Zhu Gang Chen Liming Wu 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1135-1151,共17页
Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether ... Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile. 展开更多
关键词 Food allergens Protein structural characterization Immunogenicity evaluation Food processing modification
下载PDF
Solvothermal Synthesis and Characterization of [TM(1,2-dap)3]HgSb2Se5(TM = Co,Fe)with a Chain Structure 被引量:2
8
作者 赵丽佳 赵日格吐 +1 位作者 韩文静 白音孟和 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第8期1222-1230,共9页
One organic-decorated quanternaery [TM(1,2-dap)3]Hg Sb2Se5(1,2-dap = 1,2-dianinopropane, TM = Co(1), Fe(2)) compound has been solvothermally synthesized. The compounds crystallize in triclinic space group P 1,... One organic-decorated quanternaery [TM(1,2-dap)3]Hg Sb2Se5(1,2-dap = 1,2-dianinopropane, TM = Co(1), Fe(2)) compound has been solvothermally synthesized. The compounds crystallize in triclinic space group P 1, with a = 11.248(6), b = 11.542(7), c = 12.180(12) A, V =1268.7(16) A^3, Z = 2, F(000) = 1010 for 1 and a = 11.311(5), b = 11.558(5), c = 12.180(9) A, V =1276.5(12) A^3, Z = 2, F(000) = 1008 for 2. The crystal structure consists of one-dimensional anionics chains composed of Hg Se4 tetrahedra and SbSe3 trigonal pyramids sharing corners and[TM(dap)3]^2+ cations. The [HgSb2Se+5^2-]∞ anionic chains run along the [001] direction, and are surrounded by the [TM(dap)3]^2+ cations. Meanwhile, 8-ring [Hg2Sb2Se4] and 6-ring [HgSb2Se2] are alternately found. The compounds were structurally characterized by elemental analysis,thermogravimetric analysis, infrared spectroscopy and UV-Vis diffuse reflectance spectroscopy. 展开更多
关键词 quaternary chalcogenidoantimonate solvothermal synthesis crystal structure characterization
下载PDF
Structure elucidation and in vitro rat intestinal fermentation properties of a novel sulfated glucogalactan from Porphyra haitanensis 被引量:3
9
作者 Peilin Chen Lu Liu +4 位作者 Zirun Cheng Yi Zhang Baodong Zheng Xiaoke Hu Hongliang Zeng 《Food Science and Human Wellness》 SCIE CSCD 2023年第2期596-606,共11页
This study was to investigate the structure and rat fecal microbial fermentation properties of a polysaccharide fraction(PHP2)isolated from the red marine alga Porphyra haitanensis.PHP2 was characterized as a sulfated... This study was to investigate the structure and rat fecal microbial fermentation properties of a polysaccharide fraction(PHP2)isolated from the red marine alga Porphyra haitanensis.PHP2 was characterized as a sulfated glucogalactan,with a hypothetical backbone structure of→4)Gα(1→6)G4 Sβ(1→4)Glc(1→and a side chain of Man(1→6)Glc.PHP2 had an irregular spherical chain conformation.The 16 S r RNA sequence analysis revealed that PHP2 modulated the rat fecal micro-flora composition,with a similar effect to inulin,changing the dominant genus(Lactobacillus and Escherichia-Shigella)and promoting the growth of organisms that degrade sulfur-containing polysaccharides,such as Desulfovibrio,Ruminococcaceae_UCG-005,and Ruminococcus_2.PHP2 can promote production of acetic,propionic and butyric acid by rat fecal micro-flora.Prediction of metabolic function suggested that PHP2 could modulate cholesterol metabolism.The sulfated glucogalactan fermentation behavior may be associated with its monosaccharide composition,chain branching and chain conformation.PHP2 appeared to have considerable potential as functional food,and was associated with sulfur-containing polysaccharides in general. 展开更多
关键词 Porphyra haitanensis structure characterization Fecal microflora Short-chain fatty acids Metabolic function prediction POLYSACCHARIDE
下载PDF
Micro-and Nano-structure Characterization of Isotropic Pyrocarbon Obtained via Chemical Vapor Deposition in Hot Wall Reactor
10
作者 Kezhi Li,Dongsheng Zhang,Lingjun Guo and Hejun Li State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi an 710072,China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2010年第12期1133-1138,共6页
The hot wall reactor was used to deposit isotropic pyrocarbon. The density of the product was measured by Archimedes method. The fracture morphology and texture of the product were investigated by scanning electron mi... The hot wall reactor was used to deposit isotropic pyrocarbon. The density of the product was measured by Archimedes method. The fracture morphology and texture of the product were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Raman spectroscopy was also applied to characterizing the structure of the product. The results show that the density of the product is about 1.31 g/cm^3. The pyrocarbon consists of granular particles with the size of about 1.5 μm under SEM images. Under TEM images, the pyrocarbon is composed of irregular grains and onion-like particles are also detected. The orientation angle (180 deg.) of pyrocarbon reveals its isotropic character. The ID/IG ratio in Raman spectrum is about 1.2, indicating the isotropic feature of the product qualitatively. 展开更多
关键词 Isotropic pyrocarbon Chemical vapor deposition structure characterization Onion-like pyrocarbon
原文传递
A facile method for fabrication of nano-structured Ni-Al_2O_3 graded coatings: Structural characterization 被引量:1
11
作者 Arash YAZDANI Taghi ISFAHANI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第1期77-87,共11页
Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings w... Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings were fabricated using powdermixtures with a wide range of Ni/Al2O3mass ratio varying from1:1to plain Ni.XRD,SEM and TEM techniques were employed tostudy the structural characteristics of the coatings.It was found that the composition of the starting mixture strongly affects the Al2O3content and the microstructure of the final coating.Mixtures containing higher contents of Al2O3yield higher volume fractions of theAl2O3particles in the coating.Though Ni-Al2O3composite coatings with about50%of Al2O3particles were successfully deposited,well-compacted and free of cracks and/or voids coatings included less than20%(volume fraction)of Al2O3particles which weredeposited from powder mixtures with Ni/Al2O3mass ratios of4:1or higher.Moreover,mechanical and metallurgical bondings arethe main mechanisms of the adhesion of the coating to the Al substrate.Finally,functionally graded composite coatings withnoticeable compaction and integrity were produced by deposition of two separate layers under identical coating conditions. 展开更多
关键词 metal matrix composite Ni-Al2O3 graded coating structural characterization
下载PDF
The structural characteristics of dietary fibers from Tremella fuciformis and their hypolipidemic effects in mice 被引量:9
12
作者 Shanshan Zhang Xinle Xu +1 位作者 Xu Cao Tingting Liu 《Food Science and Human Wellness》 SCIE CSCD 2023年第2期503-511,共9页
In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X... In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X-ray diffraction analysis(XRD)and scanning electron microscopy(SEM).We analyzed their lipidlowering properties in vitro(water holding,oil holding swelling cholesterol and sodium cholate binding capacitises)and the hypolipidemic effects in mice.The results showed that tremella dietary fibers presented the infrared absorption spectrum characteristics of polysaccharides and the characteristic diffraction peaks of cellulose type I.SEM results indicated that the surface of insoluble dietary fiber(IDF)was porous,while the soluble dietary fiber(SDF)was relatively compact and spongy.IDF exhibited significantly higher water holding,oil holding,and swelling binding capacities than the corresponding SDF.However,SDF exhibited significantly higher viscosity than IDF.The results showed tremella dietary fibers were significant in swelling,water holding and oil holding,cholesterol and bile acids.In vivo experiment results in mice indicated that SDF has the best effect on hyperlipidemia mice than IDF and total dietary fiber(TDF).SDF showed that the total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)contents dropped by 28.33%,18.65%,and 48.97%,respectively,while high density lipoprotein cholesterol(HDL-C)content increased by 43.80%.Compared with the high-fat control(HCM)group,the arteriosclerosis index(AI)and liver index(LI)of the SDF group mice showed significant differences,indicating that SDF has a good auxiliary effect of lowering blood lipids.The administration of tremella fibers improved the lipid metabolism disorderly situation of hyperlipidemia mice.These results provide a reference for further research and rational development of T.fuciformis. 展开更多
关键词 Tremella fuciformis Dietary fiber Structural characterization Hypolipidemic effects
下载PDF
Studies on a Novel Characteristic Atom-pair Holographic Code Applied to Quantitative Structure-chromatographic Retention Relationship of Organic Compounds 被引量:1
13
作者 ZHOU Peng TIAN Fei-Fei +1 位作者 WANG Jiao-Na LI Zhi-Liang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第11期1337-1342,共6页
6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond len... 6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond lengths in the molecule. On the basis of them, a novel molecular coding technique: characteristic atom-pair holographic code (CAHC), is obtained. To some extent, this method exhibits a large number of benefits at the same time. For example, it can calculate 2D molecular topological descriptor easily, operate without difficulty and possess definite physicochemical meaning of 3D molecular structural characterization methods, and may fetch the complicated information of molecule, etc. Therefore, it is appropriate for the study on quantitative structure-property/activity relationship (QSPR/QSAR) of medicines and biological molecules. We attempt in this paper to utilize the method of CAHC to the quantitative prediction of reversed-phase liquid chromatogram (RPLC) retention data of 33 purine derivatives and 24 steroids. The fitting multiple correlation coefficient R2, cross-validated multiple correlation coefficient Q2 and predicted ability Q^2 pred over test set's samples of obtained partial least-square (PLS) regression model are respectively 0.990, 0.893 and 0.977, 0.897, 0.941. 展开更多
关键词 characteristic atom-pair holographic code quantitative structure-chromatographic retention relationship characterization of molecular structure partial least-square regression
下载PDF
Characterization of Interface State Density of Ni/p-GaN Structures by Capacitance/Conductance-Voltage-Frequency Measurements 被引量:1
14
作者 Zhi-Fu Zhu He-Qiu Zhang +4 位作者 Hong-Wei Liang Xin-Cun Peng Ji-Jun Zou Bin Tang Guo-Tong Du 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第9期82-86,共5页
For the frequency range of I kHz-lOMHz, the interface state density of Ni contacts on p-GaN is studied using capacitance-voltage (C-V) and conductance-frequency-voltage (G-f-V) measurements at room temperature. To... For the frequency range of I kHz-lOMHz, the interface state density of Ni contacts on p-GaN is studied using capacitance-voltage (C-V) and conductance-frequency-voltage (G-f-V) measurements at room temperature. To obtain the real capacitance and interface state density of the Ni/p-GaN structures, the effects of the series resistance (Rs) on high-frequency (SMHz) capacitance values measured at a reverse and a forward bias are investigated. The mean interface state densities obtained from the CHF-CLF capacitance and the conductance method are 2 ×1012 e V-1 cm-2 and 0.94 × 1012 eV-1 cm-2, respectively. Furthermore, the interface state density derived from the conductance method is higher than that reported from the Ni/n-GaN in the literature, which is ascribed to a poor crystal quality and to a large defect density of the Mg-doped p-GaN. 展开更多
关键词 GaN characterization of Interface State Density of Ni/p-GaN structures by Capacitance/Conductance-Voltage-Frequency Measurements NI
下载PDF
Structure and Semiconducting Character of a Polymeric Iodoplumbate Coordination Complex
15
作者 宋德生 刘长春 +2 位作者 陈恒隽 苏东坡 傅志勇 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第8期1142-1146,共5页
A new polymeric iodoplumbate complex [Zn(DMF)6][Pb2I6] 1 has been prepared and characterized by elemental analysis and single-crystal X-ray analysis. Its structure contains infinite iodoplumbate chains constructed b... A new polymeric iodoplumbate complex [Zn(DMF)6][Pb2I6] 1 has been prepared and characterized by elemental analysis and single-crystal X-ray analysis. Its structure contains infinite iodoplumbate chains constructed by the [PbI5] subunit. EHT crystal orbital calculation and the experimental results show that this material is an unconventional semiconductor and the electrical character is associated with its structural feature. 展开更多
关键词 iodoplumbate coordination polymer structure and characterization semiconducting property
下载PDF
A DIACETYLENE CONTAINING α-NITRONYL NITROXIDE——SYNTHESIS,CRYSTAL STRUCTURE AND MAGNETIC CHARACTERIZATION
16
作者 De Qing ZHANG Wen Sheng ZhOU~a Dao Ben ZHU Institute of Chemistry,Academia Sinica,Beijing 100080 a.Dept,of Physics,Peking University,Beijing 100871 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第4期287-288,共2页
The mono-α-nitronyl nitroxide substituted diacetylene was synthesized and its structure was established by EA,FAB-MS,IR,ESR and x-ray diffraction analysis.Using the Extracting Sample Magnetometer,its magnetic propert... The mono-α-nitronyl nitroxide substituted diacetylene was synthesized and its structure was established by EA,FAB-MS,IR,ESR and x-ray diffraction analysis.Using the Extracting Sample Magnetometer,its magnetic properties was investigated,and the results indicate that this compound possesses antiferromagnetic properties. 展开更多
关键词 NITRONYL NITROXIDE SYNTHESIS CRYSTAL structure AND MAGNETIC characterIZATION A DIACETYLENE CONTAINING
下载PDF
ELECTRONIC STRUCTURE AND BOND CHARACTER OF COMPLEXES OF RARE EARTH CHLORIDES WITH CROWN ETHERS
17
作者 李振祥 周清廉 +5 位作者 胡宁海 倪嘉缵 任镜清 黎乐民 赵井泉 徐光宪 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第4期241-245,共5页
A series of lanthanide complexes LnCl_3·L(Ln=La,Pr,Nd;L=15-C-5 or 18-C-6)have been synthesized and their molecular configuration,electronic structure and bond character have been studied by XPS and quantum chemic... A series of lanthanide complexes LnCl_3·L(Ln=La,Pr,Nd;L=15-C-5 or 18-C-6)have been synthesized and their molecular configuration,electronic structure and bond character have been studied by XPS and quantum chemical calculation.The calculated results are in good agreement with that obtained in the experiments.Three Cl atoms are on the same side of Ln in LnCl_3·15-C-5 and the crown ring on the other side.forming a complex molecule with coordination number 8.LnCl_3·15-C-5 is easily hygroscopic in air because of its unsaturated coordination,which differs sharply from the stable Ln(NO_3)_3·15-C-5 com- plex of coordination number 11.The HOMO and neighboring occupied MOs are composed of Cl 3p and O2p, and the LUMO and neighboring unoccupied MOs are composed of Ln orbitals.The level structure easily pro- duces Ln3d satellite in XPS caused by L→Ln charge transfer transition.Due to the coordination,the absolute values of the charge are decreased at Ln and O atoms,but increased at Cl atoms,which is in agreement with XPS results. 展开更多
关键词 ELECTRONIC structure AND BOND character OF COMPLEXES OF RARE EARTH CHLORIDES WITH CROWN ETHERS CI THAN
下载PDF
STUDY ON SYNTHESIS,CHARACTERIZATION AND STRUCTURE OF A NEW RARE EARTH COORDINATION COMPOUND WITH BENZOIC ACID
18
作者 段治邦 金钟声 +1 位作者 胡宁海 倪嘉缵 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第2期81-86,共6页
In this paper,a new rare earth benzoate coordination compound,[TbL_3(HL)(H_2O)]_2 (HL=C_7H_6O_2=benzoic acid) is synthesized and characterized by elemental analysis DTA,TG,DTC,and IR spectra.The title compound crystal... In this paper,a new rare earth benzoate coordination compound,[TbL_3(HL)(H_2O)]_2 (HL=C_7H_6O_2=benzoic acid) is synthesized and characterized by elemental analysis DTA,TG,DTC,and IR spectra.The title compound crystallizes in triclinic,space.group P with a=9.148(1),b=11.460(2), c=13.506(2);α=112.76(1),β=91.83(1),γ=91.99(1)°;Z=1;V=1303.3.The final R factor is 0.0235.The rare earth ion is nine-coordinated to form a distorted monocapped square antiprism. 展开更多
关键词 STUDY ON SYNTHESIS characterIZATION AND structure OF A NEW RARE EARTH COORDINATION COMPOUND WITH BENZOIC ACID
下载PDF
SYNTHESIS,CHARACTERIZATION AND CRYSTAL STRUCTURES OF η~5-CH_3C_5H_4)M(CO)_2NO AND(η~5-CH_3C_5H_4)M(μ_3-NH)(μ_2-NO)(μ_2-CO)Fe_2(CO)_6(M=Mo or W)
19
作者 Wen Hua SUN Shi Yan YANG +1 位作者 Yuan Ci YIN Lanzhou Institute of Chemical Physics Chinese Academy of Sciences,Lanzhou 730000 Kai Bei YU Zhong Yuan ZHOU Chengdu Center of Analysis and Test Chinese Academy of Sciences,Chengdu 610015 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第3期263-266,共4页
Synthesis of complexes(η;-CH;C;H;)M(CO);NO(M=Mo,I;M=W,II)and clusters(η;-CH;C;H;)M(μ;-NH)(μ;-NO) (μ;-CO)Fe;(CO);(M=Mo,III:M=W,IV),based on the reaction of (η;-C5;)M(CO);Cl with Na[Fe(CO);NO... Synthesis of complexes(η;-CH;C;H;)M(CO);NO(M=Mo,I;M=W,II)and clusters(η;-CH;C;H;)M(μ;-NH)(μ;-NO) (μ;-CO)Fe;(CO);(M=Mo,III:M=W,IV),based on the reaction of (η;-C5;)M(CO);Cl with Na[Fe(CO);NO] at room tem-perature,have been demonstrated,The crystal structures of II and IV arealso presented. 展开更多
关键词 Fe M=Mo or W CH3C5H4)M AND M SYNTHESIS characterIZATION AND CRYSTAL structureS OF CO)Fe2 MO NO NH
下载PDF
Structural characterizations andα-glucosidase inhibitory activities of four Lepidium meyenii polysaccharides with different molecular weights
20
作者 Luan Wen Zhou-Wei Wu +3 位作者 Li-Wu Lin Abdulbaset Al-Romaima Xing-Rong Peng Ming-Hua Qiu 《Natural Products and Bioprospecting》 CSCD 2023年第1期568-576,共9页
Four polysaccharides(MCPa,MCPb,MCPc,MCPd)were obtained from Lepidium meyenii Walp.Their structures were characterized by chemical and instrumental methods including total sugar,uronic acid and protein content determi-... Four polysaccharides(MCPa,MCPb,MCPc,MCPd)were obtained from Lepidium meyenii Walp.Their structures were characterized by chemical and instrumental methods including total sugar,uronic acid and protein content determi-nation,UV,IR and NMR spectroscopy,as well as monosaccharide composition determination and methylation analy-ses.Four polysaccharides were a group of glucans with different molecular weights ranging from 3.12 to 14.4 kDa,and shared a similar backbone chain consisting of(1→4)-glucose linkages with branches attached to C-3 and C-6.Furthermore,bioactivity assay showed that MCPs had concentration-dependent inhibitory activity onα-glucosidase.MCPb(Mw=10.1 kDa)and MCPc(Mw=5.62 kDa)with moderate molecular weights exhibited higher inhibitory activ-ity compared with MCPa and MCPd. 展开更多
关键词 Lepidium meyenii POLYSACCHARIDE Molecular weight Structural characterization α-Glucosidase inhibition
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部