期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
盐酸班布特罗多晶型的鉴别 被引量:3
1
作者 华丹宇 杨良衍 周英兰 《中国医药工业杂志》 CAS CSCD 北大核心 1999年第7期315-317,共3页
采用差示扫描显热法和红外光谱分析法,对盐酸班布特罗的多晶型作了鉴别,并就其晶型的转换作了讨论。
关键词 盐酸班布特罗 晶型 差示扫描显热法 红外光谱
下载PDF
Fabrication and Mechanical Properties of 2024 Aluminum Alloy Reinforced by FeNiCrCoAl_3 High Entropy Particles 被引量:2
2
作者 Zhi-Wei Wang Rui-Xiao Zheng +2 位作者 Chao-Li Ma Li-Rong Hao Yang Han 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第5期119-122,共4页
This article mainly discussed bulk material lHvl^ared by powder metallurgy, and the commercial 2024 aluminum alloy powder and FeNiCrCoA13 high entropy alloy powder (both produced by argon gas atomization process) we... This article mainly discussed bulk material lHvl^ared by powder metallurgy, and the commercial 2024 aluminum alloy powder and FeNiCrCoA13 high entropy alloy powder (both produced by argon gas atomization process) were ball-milled for different hours. The prepared powder was consolidated by hot extrusion method. The microstruetures of the milled powder and bulk alloy were examined by X - Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The thermal stability was tested by differential scanning calorimetry (DSC). Mechanical properties of the extruded alloy were examined by Vickers hardness tester and mechanical testing machine. The results show that after milling, the mixed particle sizes and microstructures of the alloy powder change obviously. The compressive strength of the extruded alloy has reached 580 MPa under certain conditions of milling time and composition. 展开更多
关键词 aluminum alloy nanocrystaUine FeNiCrCoA13 high entroy reinforced particle ball milling(BM) the extruded alloy
下载PDF
Preparation and Characterization of TiO_2/Expanded Graphite 被引量:1
3
作者 赖奇 朱世富 +3 位作者 刘国钦 邹敏 李玉峰 罗学萍 《Transactions of Tianjin University》 EI CAS 2010年第2期156-159,共4页
In order to obtain anatase TiO2/expanded graphite with high expansion volume, titania gel was introduced to expandable graphite surface by sol-gel process, and then the composite was expanded and calcined at high temp... In order to obtain anatase TiO2/expanded graphite with high expansion volume, titania gel was introduced to expandable graphite surface by sol-gel process, and then the composite was expanded and calcined at high tempera- ture. The samples were analysed by using scanning electron microscope (SEM), X-ray diffraction(XRD), energy disperse spectroscopy (EDS), and differential scanning calorimetry (DSC). The optimal conditions for preparation are as follows: the molar ratio of tetrabutyl orthotitanate to triethanolamine is 1 : 0.4, and the calcination and expansion temperature is in the range of 650--750 ~C. Under such conditions, the expansion volume of composites could reach 98 mE/g, and the mass loss ratio is less than 5%. The analysis shows that lower temperature and smaller particle size of graphite are helpful to the formation of anatase-type of TiO2, but larger particle size will lead to lower mass loss ratio, and higher temperature and larger particle size will lead to higher expansion volume. 展开更多
关键词 expanded graphite titanium dioxide COMPOSITE PREPARATION
下载PDF
Recovery of high specific area silica and sodium fluoride from sodium hexafluorosilicate 被引量:4
4
作者 徐徽 李贵 +1 位作者 程俊峰 刘卫平 《Journal of Central South University》 SCIE EI CAS 2014年第11期4084-4090,共7页
Sodium fluoride and high specific area silica were synthesized by using sodium hexafluorosilicate(Na2Si F6) and sodium carbonate decahydrate(Na2CO3·10H2O). The influencing factors of react temperature, contact ti... Sodium fluoride and high specific area silica were synthesized by using sodium hexafluorosilicate(Na2Si F6) and sodium carbonate decahydrate(Na2CO3·10H2O). The influencing factors of react temperature, contact time, sodium dodecyl sulfate(SDS) and molar ratio of Na2 Si F6 to Na2CO3·10H2O were investigated. The optimum process involves the reaction of 0.075 mol Na2 Si F6 and 150 m L, 0.225 mol Na2CO3·10H2O(molar ratio of 1:3) at 85 °C for 90 min, and 2.0×10-3 mol sodium dodecyl sulfate(SDS) as additive. The results show that the purities of Si O2 and Na F at extraction yields of 96.5% and 98.0% are 91.0% and 98.6%, respectively. The obtained Si O2 were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared ray(FTIR), differential scanning calorimetry and thermogravimetric analysis(DSC-TGA), N2 absorption/desorption(BET) and laser particle size analyzer. The result demonstrates that Si O2 particles have a high BET surface area of 103 m2/g, and a mean grain size of 985 nm. 展开更多
关键词 recovery sodium hexafluosilicate sodium fluoride silica
下载PDF
Characterization of calcium deposition induced by Synechocystis sp. PCC6803 in BG11 culture medium 被引量:7
5
作者 闫华晓 韩作振 +8 位作者 赵辉 周仕学 迟乃杰 韩梅 寇小燕 张艳 徐琳琳 田晨晨 秦松 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第3期503-510,共8页
Calcium carbonate (CaCO3) crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 (inoculated BG11). In this study, the features of calcium carbonate d... Calcium carbonate (CaCO3) crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 (inoculated BG11). In this study, the features of calcium carbonate deposition were investigated. Inoculated BGll in different calcium ion concentrations was used for the experimental group, while the BGll culture medium was used for the control group. The surface morphologies of the calcium carbonate deposits in the experimental and control groups were determined by scanning and transmission electron microscopy. The deposits were analyzed by electronic probe micro-analysis, Fourier transform infrared spectrum, X-ray diffraction, thermal gravimetric analysis and differential scanning calorimetry. The results show that the surfaces of the crystals in the experimental group were hexahedral in a scaly pattern. The particle sizes were micrometer-sized and larger than those in the control group. The deposits of the control group contained calcium (Ca), carbon (C), oxygen (O), phosphorus (P), iron (Fe), copper (Cu), zinc (Zn), and other elements. The deposits in the experimental group contained Ca, C, and O only. The deposits of both groups contained calcite. The thermal decomposition temperature of the deposits in the control group was lower than those in the experimental group. It showed that the CaCO3 deposits of the experimental group had higher thermal stability than those of the control group. This may be due to the secondary metabolites produced by the algae cells, which affect the carbonate crystal structure and result in a close-packed structure. The algae cells that remained after thermal weight loss were heavier in higher calcium concentrations in BGll culture media. There may be more calcium- containing crystals inside and outside of these cells. These results shall be beneficial for understanding the formation mechanism of carbonate minerals. 展开更多
关键词 Synechocystis sp. PCC6803 preferred orientation BIOMINERALIZATION calcium carbonate thermal stability
下载PDF
Effects of solution treatment on mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy 被引量:4
6
作者 YU Cheng YIN Deng-feng +1 位作者 ZHENG Feng YU Xin-xiang 《Journal of Central South University》 SCIE EI CAS 2013年第8期2083-2089,共7页
Mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy after solution treatments were investigated by means of optical microscopy (OM), tensile test, hardness measurement and electrical conductivity test,... Mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy after solution treatments were investigated by means of optical microscopy (OM), tensile test, hardness measurement and electrical conductivity test, differential scanning calorimetric (DSC), energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transition electron microscopy (TEM), respectively The results show that both tensile strength and hardness increase first and then decrease with temperature at constant holding time of 30 min with maximum strength and hardness appearing at 520 ℃. Tensile strength, hardness and elongation of samples treated at 520 ℃ for 30 min are 566 MPa (σb), 512 MPa (σ0.2), HB 148 and 8.23% (δ), respectively. There are certain amount of fine T1 (AI2CuLi) phase dispersing among AI substrates according to TEM images. This may result in mixed fracture morphology with trans-granular and inter-granular delamination cracks observed in SEM images. 展开更多
关键词 Al-Li-Cu-Mg-Ag alloy solution treatment microstructure mechanical properties
下载PDF
Preparation and Characterization of Gelatins from Two Sudanese Edible Insects 被引量:1
7
作者 A. A. Mariod S. I. Abdelwahab +3 位作者 M. Y. Ibrahim S. Mohan M. Abd Elgadir N. M. Ain 《Journal of Food Science and Engineering》 2011年第1期45-55,共11页
Gelatins extracted from two edible insects Aspongubus viduatus (melon bug) and Agonoscelis pubescens (sorghum bug) were studied. The two insects showed 27.0 and 28.2% crude protein, respectively. Extraction of gel... Gelatins extracted from two edible insects Aspongubus viduatus (melon bug) and Agonoscelis pubescens (sorghum bug) were studied. The two insects showed 27.0 and 28.2% crude protein, respectively. Extraction of gelatin using hot water gave high yield followed by mild acid and distilled water extraction, respectively. SDS-PAGE pattern showed low molecular weight chains, and the two gelatins contained protein with molecular weight of 40 kDa as main component. The differential scanning calorimetry thermograms results confirm no difference between extraction methods concerning the extracted gelatin quality. FTIR spectra of melon and sorghum bug gelatins were similar and the absorption bands were situated in more than 6 bands in melon bug gelatin and only 6 bands in sorghum bug gelatin. Amide II bands of gelatins from both melon and sorghum bug appeared at around 1554 cm^-1, while Amide I bands (1734-1632 cmt) appeared only in melon bug method 2 (MB2) and melon bug method3 (MB3). Microstructures of the insect gelatin examined with the scanning electron microscope showed that melon bug exhibited the finest gelatin network with very small voids. Melon bug gelatin showed finer structure with smaller protein strands and voids than sorghum bug gelatin. 展开更多
关键词 Aspongopus viduatus agonoscelis pubescens GELATIN differential scanning calorimetry fourier transform infrared spectroscopy sodium dodecyl sulphate gel electrophoresis.
下载PDF
A Pd-Fe-B/γ-Al2O3 Amorphous Alloy Catalyst for Hydrogenation of Chloronitrobenzene to Chloroaniline
8
作者 Langsong Si Yajuan Zhao Xing Huang Dandan Li Yuxiang Wang 《Journal of Chemistry and Chemical Engineering》 2010年第9期28-33,共6页
A Pd-Fe-B/γ-Al2O3 amorphous alloy catalyst was prepared by impregnation and chemical reduction with borohydrine aqueous solution. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microsc... A Pd-Fe-B/γ-Al2O3 amorphous alloy catalyst was prepared by impregnation and chemical reduction with borohydrine aqueous solution. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), differential scanning calorimetry(DSC) and elecdes design suite(EDS) and was used for catalytic hydrogenation of 5-nitro-2-chloro-2', 4'-dimethylbenzenesulfonanilide (NCD). The amorphous alloy catalyst shows significantly high activity and selectively for hydrogenation of NCD to 5-Amino-2-chloro- 2', 4'-dimethyibenzenesuifonanilide (ACD). 展开更多
关键词 Amorphous alloy catalytic hydrogenation Pd-Fe-B/γ-Al2O3 supported catalyst.
下载PDF
Performances of lithium manganese oxide prepared by hydrothermal process
9
作者 孔龙 李运姣 +3 位作者 张鹏 黄海花 叶万奇 李春霞 《Journal of Central South University》 SCIE EI CAS 2014年第4期1279-1284,共6页
A simple hydrothermal process followed by heat treatment was applied to the preparation of spinel Li1.05Mn1.95O4. In this process, electrolytic manganese dioxide(EMD) and LiOH·H2O were used as starting materials.... A simple hydrothermal process followed by heat treatment was applied to the preparation of spinel Li1.05Mn1.95O4. In this process, electrolytic manganese dioxide(EMD) and LiOH·H2O were used as starting materials. The physiochemical properties of the synthesized samples were investigated by thermogravimetry-differential scanning calorimetry(TG-DSC), X-ray diffractometry(XRD), and scanning electronic microscopy(SEM). The results show that the hydrothermally synthesized precursor is an essential amorphous. The precursor can be easily transferred to spinel powders with a homogeneous structure and a regularly-shaped morphology by heat treatment. Li1.05Mn1.95O4 powder obtained by heat treating the precursor at 430 °C for 12 h and then calcining at 800 °C for 12 h shows an excellent cycling performance with an initial charge capacity of 118.2 mA·h·g-1 obtained at 0.5C rate and 93.8% of its original value retained after 100 cycles. 展开更多
关键词 lithium ion batteries LiMn2O4 hydrothermal method heat treatment
下载PDF
Pebax/TSIL blend thin film composite membranes for CO_2 separation 被引量:2
10
作者 Zhongde Dai Lu Bai +3 位作者 Karoline Navik Hval Xiangping Zhang Suojiang Zhang Liyuan Deng 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第5期538-546,共9页
In this study a thin film composite (TFC) membrane with a Pebax/Task-specific ionic liquid (TSIL) blend selective layer was prepared. Defect-flee Pebax/TSIL layers were coated successfully on a polysulfone ultrafi... In this study a thin film composite (TFC) membrane with a Pebax/Task-specific ionic liquid (TSIL) blend selective layer was prepared. Defect-flee Pebax/TSIL layers were coated successfully on a polysulfone ultrafiltration porous support with a poly- dimethylsiloxane (PDMS) gutter layer. Different parameters in the membrane preparation (e.g. concentration, coating time) were investigated and optimized. The morphology of the membranes was studied by scanning electron microscopy (SEM), while the thermal properties and chemical structures of the membrane materials were investigated by thermo-gravimetric ana- lyzer (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The CO2 separation performance of the membrane was evaluated using a mixed gas permeation test. Experimental results show that the incorpora- tion of TSIL into the Pebax matrix can significantly increase both C02 permeance and CO2/N2 selectivity. With the presence of water vapor, the membrane exhibits the best CO2/N2 selectivity at a relative humidity of around 75%, where a CO2 permeance of around 500 GPU and a CO2/N2 selectivity of 46 were documented. A further increase in the relative humidity resulted in higher CO: permeance but decreased COIN2 selectivity. Experiments also show that CO2 permeance decreases with a CO2 partial pressure increase, which is considered a characteristic in facilitated transport membranes. 展开更多
关键词 CO2 capture thin film composite membrane task specific ionic liquids Pebax post combustion
原文传递
Intermetallic phase formation and evolution during homogenization and solution in Al-Zn-Mg-Cu alloys 被引量:10
11
作者 LI ChunMei CHEN ZhiQian +2 位作者 ZENG SuMin CHENG NanPu CHEN TianXiao 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第11期2827-2838,共12页
The effects of major alloy element contents of Zn, Mg, Cu in Al-Zn-Mg-Cu alloys on the formation and evolution of intermetallic phases during casting, homogenization and solution treatment have been investigated throu... The effects of major alloy element contents of Zn, Mg, Cu in Al-Zn-Mg-Cu alloys on the formation and evolution of intermetallic phases during casting, homogenization and solution treatment have been investigated through using X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. Experimental results showed that a relatively higher Zn content with lower Mg and Cu contents was beneficial to the formation of MgZn2 phase instead of the A12CuMg phase, which resulted in the unicity of the intermetallics in the A1 matrix, and that the MgZn2 phase was easier for diffusion and dissolution during homogenization and solution than the Al2CuMg phase. Additionally, the results of the first-principles calculations gave support for explaining the experimental phenomena. A larger absolute value of formation enthalpy and a smaller value of binding energy of the MgZn2 phase, as compared with the Al2CuMg phase, give it priority to precipitate during casting and make it easier to re-dissolve during homogenization and solution treatment. What's more, higher elastic constants with severe anisotropy of Young's modulus make undissolved blocks of AI^CuMg phase act as crack initiation, which degrade the perfor- mance of the materials. 展开更多
关键词 intermetallic phases HOMOGENIZATION SOLUTION FIRST-PRINCIPLES Al alloys
原文传递
Preparation and characterization of Al/B/Fe_2O_3 nanothermites 被引量:7
12
作者 SHEN LianHua LI GuoPing +2 位作者 LUO YunJun GAO Kun GE Zhen 《Science China Chemistry》 SCIE EI CAS 2014年第6期797-802,共6页
A sol-gel synthetic approach combined with an ultrasonic method was utilized to prepare Al/B/Fe2O3 nanothermites.The structure and properties of the prepared nanothermites were characterized by thermogravimetric analy... A sol-gel synthetic approach combined with an ultrasonic method was utilized to prepare Al/B/Fe2O3 nanothermites.The structure and properties of the prepared nanothermites were characterized by thermogravimetric analysis,differential scanning calorimetry,scanning electron microscopy,X-ray diffraction,and an impact sensitivity test.The results verified that the nano-aluminum and the micro-boron were uniformly dispersed in the pores of the iron oxide gel.The heat of the prepared Al/B/Fe2O3 nanothermites was 1.3 times that of the simple physically mixed sample.In addition,the heat of the combustion test showed that these materials were indeed energetic.Small-scale safe experiments also showed that the prepared materials through sol-gel were relatively insensitive to standard impact. 展开更多
关键词 SOL-GEL nanothermites energetic materials PROPERTIES
原文传递
Synthesis of functionalized triphenylene discotic liquid crystals and the influence of unsaturated periphery on mesomorphism 被引量:1
13
作者 ZHAO KeQing ZHOU Hui +4 位作者 YU WenHao HU Ping WANG BiQin MONOBE Hirosato SHIMIZU Yo 《Science China Chemistry》 SCIE EI CAS 2011年第10期1576-1583,共8页
Twelve triphenylene discogens with unsaturated periphery (abbreviated as C18H6(OC5H11)6-x(OR)x(x=1,2,3), R=-C3H6CH==CH2(a),-C3H6C≡CH(b),-C2H4OCH==CH2(c)) were synthesized and characterized. The thermotropic liquid cr... Twelve triphenylene discogens with unsaturated periphery (abbreviated as C18H6(OC5H11)6-x(OR)x(x=1,2,3), R=-C3H6CH==CH2(a),-C3H6C≡CH(b),-C2H4OCH==CH2(c)) were synthesized and characterized. The thermotropic liquid crystal prop-erties were studied by using polarized optical microscopy, differential scanning calorimetry and X-ray diffractometry. The results showed that all triphenylenes exhibited hexagonal columnar mesophase. The thermotropic studies showed that series a (alkene periphery) exhibited higher clearing points than the corresponding series b (alkyne periphery), while series c (vinyloxy periphery) exhibited highest clearing points and widest mesophase temperature ranges. We also found that the symmetric discogens sym-C18H6(OC5H11)3(OR)3 displayed higher melting points and clearing points than the asymmetric ones asym-C18H6(OC5H11)3(OR)3. 展开更多
关键词 discotic liquid crystal TRIPHENYLENE functional periphery hexagonal columnar mesophase mesomorphism engineering
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部