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1.
Young's modulus of elasticity, transverse strength, extensibility, and load resistance were determined at a series of test temperatures on six groups of laboratory-prepared refractory castables which had ( a ) no heat-treatment, ( b ) heat-treatment at 1050°C., and ( c ) heat-treatment at 1300°C. The data suggested that the alterations in composition that occur with a rise in temperature were related to corresponding changes in modulus of elasticity and strength. The effects of dehydration, conversion of amorphous alumina to γ-alumina, and silica inversions were evident. The cement content and temperature of operation as well as the heat-treatment of the castables affected all these mechanical properties to varying degrees. 相似文献
2.
Direct Method of Preparation of Dodecanesulfonamide Derivatives and Some Surface Properties 总被引:1,自引:1,他引:0
Alkanesulfonamide compounds are known as surfactants because of the presence of –SO2NH– function in their molecule. Thus, they are used in many formulations in the chemical and textile industries and also as
inhibitors of corrosion. Generally, sulfonamide derivatives are prepared using sulfonyl chlorides as the raw material. The
methods often described in the literature involve the use of ammonia gas and pressure. A simple and direct method to prepare
pure alkanesulfonamide derivatives possessing good surface properties is presented in this work. Thus, n-dodecanesulfonyl chlorides obtained by photochemical sulfochlorination of n-dodecane under visible light using sulfuryl chloride were separated from the reaction mixture. These sulfonyl chlorides,
a mixture of primary and secondary isomers, were transformed in one step into N-ethyldodecanesulfonamides, N-ethanoldodecanesulfonamides and the salts of dodecanesulfonamidoacetic acid. After purification on chromatographic column,
the six position isomers of these sulphonamide derivatives were analysed and well separated by gas phase chromatography using
a nonpolar column. Then, gas phase chromatography analysis coupled to mass spectrometry using electronic impact (GC/MS/IE)
was performed to identify the different position isomers. The primary isomers of sulphonamide derivatives were identified
by crossed injection of the compounds obtained by synthesis from the 1-chlorododecane using the Grignard reagent, and identified
by IR, 1H- and 13C-RMN, elementary analysis and GC/MS/IE. Some physico-chemical properties of these sulphonamide derivatives were examined.
The variation of surface tension versus the concentration of both primary and secondary sulphonamide derivatives were studied,
and the critical micellar concentration was determined for the compounds showing surface activity. The foaming power was also
determined by the Bartsch method, and the results obtained were compared to those of a commercial surfactant, the linear alkylbenzenesulfonate.
The stability of the foam formed was also evaluated.
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Amel TazeroutiEmail: |
3.
Taichi Sotani Hiroko Iwakiri Hirotaka Yamada Noritaka Shimosaraya Yu Miyagi Fumio Sanda 《大分子材料与工程》2019,304(9)
The Sonogashira–Hagihara coupling polymerization of ferrocene‐containing l ‐phenylalanine‐derived optically active o‐, m‐, p‐substituted bis(iodophenylene) monomers 1o , 1m , 1p with 1,4‐diethynylbenzene ( 2 ) and 1,4‐diethynyl‐2,5‐bis[2‐(2‐methoxyethoxy)ethoxy]benzene ( 3 ) is carried out to obtain the corresponding polymers consisting of ferrocene, amino acid, and phenyleneethynylene moieties. In the solution state, poly( 1o ‐ 2 ), poly( 1o‐3 ), and poly( 1m ‐ 2 ) exhibit no circular dichroism (CD) signals in N,N‐dimethylformamide (DMF), while poly( 1m‐3 ), poly( 1p ‐ 2 ), and poly( 1p ‐ 3 ) exhibit CD signals assignable to the main chain chromophore, indicating the formation of certain chiral structures. In the solid state, poly( 1o ‐ 2 ), poly( 1o‐3 ), poly( 1m ‐ 2 ), and poly( 1m‐3 ) exhibit CD signals in the solid state, while poly( 1p ‐ 2 ), poly( 1p ‐ 3 ) does not, indicating the different aggregation manners of the polymers in the solution and solid states. The monomer and the polymers exhibit redox properties assignable to the ferrocene moieties. Thermal gravimetry analysis (TGA) measurements reveal that a 30% weight reduction occurs at 500 °C yielding black ferromagnetic solids. 相似文献
4.
Byoung‐Jik Jeong Mi‐Ri Joung Jin‐Seong Kim Sahn Nahm Ji‐Won Choi Seong‐Ju Hwang 《Journal of the American Ceramic Society》2013,96(12):3742-3746
A homogeneous Bi12TiO20 phase was developed in a specimen that was calcined at 700°C without the formation of a secondary phase. A small amount of the Bi12TiO20 phase melted during sintering and assisted the densification of the specimen. The Bi2O3 and Bi8TiO14 secondary phases were found in all specimens. All the specimens that were sintered at temperatures ≥775°C exhibited high relative densities above 98% of the theoretical density. The Q × f value of the Bi12TiO20 ceramics was influenced by the grain size. The Bi12TiO20 ceramics sintered at 800°C for 5 h showed promising microwave dielectric properties of εr = 41, Q × f = 10 400 GHz, and τf = ?10.8 ppm/°C. 相似文献
5.
Megakaryocytes are large hematopoietic cells present in the bone marrow cavity, comprising less than 0.1% of all bone marrow cells. Despite their small number, megakaryocytes play important roles in blood coagulation, inflammatory responses, and platelet production. However, little is known about changes in gene expression during megakaryocyte maturation. Here we identified the genes whose expression was changed during K562 leukemia cell differentiation into megakaryocytes using an Affymetrix GeneChip microarray to determine the multifunctionality of megakaryocytes. K562 cells were differentiated into mature megakaryocytes by treatment for 7 days with phorbol 12-myristate 13-acetate, and a microarray was performed using RNA obtained from both types of cells. The expression of 44,629 genes was compared between K562 cells and mature megakaryocytes, and 954 differentially expressed genes (DEGs) were selected based on a p-value < 0.05 and a fold change >2. The DEGs was further functionally classified using five major megakaryocyte function-associated clusters—inflammatory response, angiogenesis, cell migration, extracellular matrix, and secretion. Furthermore, interaction analysis based on the STRING database was used to generate interactions between the proteins translated from the DEGs. This study provides information on the bioinformatics of the DEGs in mature megakaryocytes after K562 cell differentiation. 相似文献
6.
Microstructural and Microwave Dielectric Properties of Bi12GeO20 and Bi2O3‐Deficient Bi12GeO20 Ceramics
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Xing‐Hua Ma Sang‐Hyo Kweon Sahn Nahm Chong‐Yun Kang Seok‐Jin Yoon Young‐Sik Kim Won‐Sang Yoon 《Journal of the American Ceramic Society》2016,99(7):2361-2367
Bi12GeO20 ceramics sintered at 800°C had dense microstructures, with an average grain size of 1.5 μm, a relative permittivity (εr) of 36.97, temperature coefficient of resonance frequency (τf) of ?32.803 ppm/°C, and quality factor (Q × f) of 3137 GHz. The Bi12‐xGeO20‐1.5x ceramics were well sintered at both 800°C and 825°C, with average grain sizes exceeding 100 μm for x ≤ 1.0. However, the grain size decreased for x > 1.0 because of the Bi4Ge3O12 secondary phase that formed at the grain boundaries. Bi12‐xGeO20‐1.5x (x ≤ 1.0) ceramics showed increased Q × f values of >10 000 GHz, although the εr and τf values were similar to those of Bi12GeO20 ceramics. The increased Q × f value resulted from the increased grain size. In particular, the Bi11.6GeO19.4 ceramic sintered at 825°C for 3 h showed good microwave dielectric properties of εr = 37.81, τf = ?33.839 ppm/°C, and Q × f = 14 455 GHz. 相似文献
7.
Young-Keun Kim Hyo-Jin Kang Young-Wook Jang Su-Bin Lee Seung-Min Lee Ki-Suck Jung Jin-Kook Lee Mi-Ra Kim 《International journal of molecular sciences》2008,9(12):2745-2756
We have synthesized soluble TiOPc derivatives containing alkoxy groups for use as additives in dye-sensitized solar cells (DSSCs). The DSSC devices containing these TiOPc derivatives exhibited short-circuit current densities of 8.49~10.04 mA/cm2 and power conversion efficiencies of 2.73~3.62 % under AM 1.5 illumination and 100 mW/cm2 irradiation. 相似文献
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9.
通过钯催化的Buchwald-Hartwig反应合成了三种新型的氟代四苯基联苯二胺衍生物N,N'-二苯基-N,N--二(2,4-二氟苯基)-[1,1’-联苯]-4,4’-二胺(TFTPB1),N,N’-二苯基-N,N’-二(3,4-二氟苯基)-[1,1’-联苯]-4,4’-二胺(TFTPB2)和N,N’-二苯基-N,N... 相似文献
10.
Synthesis,Characterization, and Antileukemic Properties of Naphthoquinone Derivatives of Lawsone
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Ryuta Inagaki Masayuki Ninomiya Prof. Kaori Tanaka Prof. Mamoru Koketsu 《ChemMedChem》2015,10(8):1413-1423
Naphthoquinones are considered privileged structures for anticancer drug molecules. The Heck reaction of 2‐hydroxy‐1,4‐naphthoquinone (lawsone) with 1‐bromo‐3‐methyl‐2‐butene offered easy access to lapachol. Several naturally occurring linear and angular heterocyclic quinoids (α‐lapachone, β‐lapachone, dunnione, and related analogues) were prepared from lapachol. Furthermore, we demonstrated that the synthetic naphthoquinones inhibit cell proliferation in human leukemia HL‐60 cells. In particular, angular‐type derivatives were found to possess moderate cytotoxicity and to elevate the levels of intracellular glutathione disulfide (GSSG). Our work highlights the significant potential of naturally occurring angular‐series naphthoquinones as antileukemic agents. 相似文献
11.
Summary
A series of nylons with long alkylene segments between amide groups were newly prepared by step-heating melt-polycondensation
of 1,lS-octadecanedicarboxylic acid with various diamines. The prepared polyamides were characterized carefully. The results
show that many properties of the prepared nylons change regularly with the length of methylene segments in diamines. In addition,
nylon 2 20 has a relatively low molecular weight and much different melting and thermal decomposition behaviors in comparison
with other nylons.
Received: 21 June 2OO2/Revised version: 18 September 2002/ Accepted: 18 September 2002
Correspondence to Deyue Yan E-mail: dyyan@mail.sjtu.edu.cn Tel: 0086-21-54742863 Fax: 0086-21-54741297 相似文献
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13.
Several disperse dyes, derivatives of 4-N, N-dialkylaminoazobenzene having acetylamino, carbamyl, phthalimide or naphthalimide substituents have been prepared. Their spectral properties and reaction to heat were determined, and their usefulness was evaluated in terms of the sublimation fastness. It was found that the dyes containing a benzamide system with an unsubstituted NH group, similar to that in phthalimide and naphthalimide derivatives, show a high sublimation fastness due to their ability to associate. 相似文献
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15.
Fluorene Derivatives with Multi-addressable Properties: Synthesis,Characterization, and Reactivity
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Refat El-Sayed Ismail I. Althagafi Saleh A. Ahmed 《Journal of surfactants and detergents》2017,20(4):933-945
A series of novel fluorene derivatives were synthesized from the target compound N-octadecyl-9-oxo-9H-fluorene-4-carboxamide (3), which led to new functionalized five- and six-membered heterocyclic derivatives via reaction with various reagents. The synthesized compounds were allowed to react with propylene oxide to afford unique surface-active properties. The chemical structures of the newly synthesized compounds were elucidated and confirmed by spectroscopic and analytical tools. The synthesized compounds have good surface activity and the biological degradation of these fluorene-based surfactants was greater than 96% after 7 days. 相似文献
16.
Samarium oxide forms a ceramic of medium strength and density (6.0) when it is fired at 1300°C. When it is fired at 1500°C., its density is increased to 7.4 but it loses its stability toward boiling water. X-ray data are given concerning the structure of the oxide as received and at 1300°C. and of the reaction product of Sm203 with water. Gadolinium oxide forms a ceramic of somewhat higher density (7.0) at 1300° than does Sm2 O3 ; at 1500°C. its density is slightly higher (7.6) whereas its stability toward water is unchanged. Data concerning both oxides include density, shrinkage, moduli of elasticity and of rupture, linear thermal expansion, differential thermal analysis, and specific heat as well as X-ray data. Results are given of a brief survey of the reaction products obtained when Sm2 O3 and Gd2 O3 are heated at 1500°C. in equimolecular quantities with Al2 O3 , BaO, CaO, CdO, Fe2 O3 , HfO2 , MgO, SO2 , SrO, ThO2 , and ZrO2 . X-ray data for the following rare-earth oxides as received and after calcination at 1400°C. are given: ceria, praseodymia, neodymia, europia, dysprosia, holmia, erbia, thulia, and ytterbia. 相似文献
17.
Hamdy S. El-Sheshtawy Awatef S. Assran Ahmed M. AbouBaker 《Polycyclic Aromatic Compounds》2019,39(1):1-13
Synthesis of four N-(heterocyclic)-9-aminoacridine derivatives was investigated. The synthesized compounds, N-thiazolyl-9-aminoacridine (AC1), N-(1,3,4-thiadiazolyl)-9-aminoacridine (AC2), N-(5-methyl-1,3,4-thiadiazolyl)-9-aminoacridine (AC3), and N-(5-phenyl-1,3,4-thiadiazolyl)-9-aminoacridine (AC4) were characterized by FT-IR, 1H NMR, mass-spectral, and elemental analysis. Amine-imine tautomerism was suggested by density functional theory (DFT) calculations. The optimized structures were obtained using B3LYP/6–311++G(d,p) level of theory. The UV–Vis absorption spectra were measured in various organic solvents. The synthesized compounds AC1–AC4 exhibit absorption spectra characteristic of typical donor–acceptor compounds. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) analysis have been used to explain the internal charge transfer (ICT) phenomena within the molecules. Also, simulated UV spectra were calculated using TD-DFT (B3LYP/6–311++G(d,p) and the results were compared with the experimental values. 相似文献
18.
以5-溴靛红和2,5-二溴吡啶为原料,合成了2,8-二溴-11H-吡啶并[2,1-b]喹唑-11-酮(Ⅱ),再通过Suzuki偶联反应在分子两侧用三芳胺等供电子基团进行了修饰,合成了3个喹唑啉酮衍生物,收率在68%~85%,其结构经1HNMR、13CNMR和MS确证。通过UV-Vis、FL测试考察了其光学性能,用循环伏安法和理论计算考察了其电化学性质。结果表明:在喹唑啉酮母体分子两侧接入供电子基团延长了分子的π共轭体系,增加了喹唑啉酮母体两侧的空间位阻,减少了分子间的π-π堆积,两侧的供电子基团与喹唑啉酮母体形成了推挽结构,有利于分子内的电子转移,减少电子由基态到激发态的跃迁能,其中接入三芳胺基团的2,8-双(4-(二苯基氨基)苯基)-11H-吡啶并[2,1-b]喹唑-11-酮(Ⅲa)的能带隙(Egap)最小,为2.2533 eV,而未修饰的喹唑啉酮母环(Ⅰ)的能带隙Egap为2.7231 eV。喹唑啉酮化合物的能带隙具有明显优势,该类化合物是一类潜在的三阶非线性光学功能材料。 相似文献
19.
J. Feitelson 《Israel journal of chemistry》1970,8(2):241-252
The fluorescence quantum yields of tryptophan, 3-methylindole and 3-β-hydroxyethylindole were investigated as a function of temperature in a variety of polar and non polar solvents. Similar quantum yields and “activation energies” were found for the different systems. It was concluded that the same collisional solvent deactivation is responsible for the decrease in quantum yield with temperature irrespective of solvent system used. A notable exception is water where a different mechanism is indicated. The quenching of the indole chromophore fluorescence by a variety of specific agents both attached to the ring by an ethylene bridge and in homogeneous solution was also studied. It was found that potential proton donating groups were good quenching agents, the effect being much greater for groups carrying a positive charge. Polarization by a neighboring group also enhanced the quenching ability of any specific group. It was concluded that an excited state charge transfer complex is probably involved as a first step in the quenching process. 相似文献