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有机硅消泡剂和羧化物消泡剂对表面施胶液不同的消泡抑泡效果
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作者 樊国柱 《造纸化学品》 CAS 2011年第B09期33-35,共3页
在消泡剂绝干质量对氧化淀粉绝干质量用量相同的情况下,改变消泡剂用量,研究了有机硅消泡剂和羧化物消泡剂对所配制的表面施胶液的消泡、抑泡效果,探讨了使用这2种消泡剂的利与弊。实验结果表明,在同等用量情况下,有机硅消泡剂消泡抑泡... 在消泡剂绝干质量对氧化淀粉绝干质量用量相同的情况下,改变消泡剂用量,研究了有机硅消泡剂和羧化物消泡剂对所配制的表面施胶液的消泡、抑泡效果,探讨了使用这2种消泡剂的利与弊。实验结果表明,在同等用量情况下,有机硅消泡剂消泡抑泡效果要强于羧化物消泡剂。 展开更多
关键词 有机硅 羧化物 表面施胶液 消泡 抑泡
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通过二羧化物中间体制备苯氧基链烷酸、链烯酸和炔酸及其盐的方法
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《化工中间体导刊》 2005年第15期22-22,共1页
本发明涉及通过二羧化物中间体从含苯氧基的化合物制备苯氧基链烷酸、链烯酸和炔酸及其盐的方法。通过这种方法制备的苯氧基链烷酸,链烯酸和快酸及其盐适合于在向动物给药的经口服或其他途径呈递活性剂的组合物中使用。而且,本发明涉... 本发明涉及通过二羧化物中间体从含苯氧基的化合物制备苯氧基链烷酸、链烯酸和炔酸及其盐的方法。通过这种方法制备的苯氧基链烷酸,链烯酸和快酸及其盐适合于在向动物给药的经口服或其他途径呈递活性剂的组合物中使用。而且,本发明涉及向靶点呈递活性剂,诸如生物或化学活性剂的苯氧基二羧酸及其盐。 展开更多
关键词 苯氧基链烷酸 链烯酸 炔酸 羧化物中间体 制备方法
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日本梨成熟果实中编码1-氨基环丙烷-1-羧化物(ACC)合成酶(PPACS3)的cDNA的克隆和其特征
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作者 AkihiroItai KengiTanabe 邱敦莲 《国外作物育种》 2004年第2期38-39,共2页
植物激素乙烯调节很多生理过程,如种子发芽、果实成熟、脱落和衰老等。已有人详细地介绍过乙烯生物合成路径,在这条路径中,涉及ACC合成酶和ACC氧化酶两种酶。最近有人已从各种植物中分离到编码这两种酶的cDNA和基因组克隆。
关键词 成熟果实 1-氨基环丙烷-1-羧化物合成酶 ACC合成酶 CDNA克隆
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Syntheses and catalytic performances of three coordination polymers with tetracarboxylate ligands
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作者 MEI Zhenzhong WANG Hongyu +2 位作者 KANG Xiuqi SHAO Yongliang GU Jinzhong 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第9期1795-1802,共8页
Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed... Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed hydrothermally using H4adip(H4adip=5,5′-azanediyldiisophthalic acid),phen(phen=1,10-phenanthroline),bipy(bipy=2,2′-bipyridine),bpa(bpa=bis(4-pyridyl)amine),and zinc and cobalt chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffrac-tion analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the orthorhom-bic system Pnna(1 and 2)or P21212(3)space groups.All compounds exhibit 3D frameworks.The catalytic perfor-mances in the Henry reaction of these compounds were investigated.Compound 3 exhibited an effective catalytic activity in the Henry reaction at 70℃.CCDC:2339391,1;2339392,2;2339393,3. 展开更多
关键词 coordination polymer tetracarboxylic acid catalytic properties Henry reaction
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Syntheses,crystal structures,and catalytic properties of three zinc(Ⅱ),cobalt(Ⅱ)and nickel(Ⅱ)coordination polymers constructed from 5⁃(4⁃carboxyphenoxy)nicotinic acid
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作者 LING Weizhong CHEN Xiangyun +2 位作者 LIU Wenjing HUANG Yingkai LI Yu 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第9期1803-1810,共8页
Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been construc... Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been constructed hydrothermally using H_(2)cpna(5-(4-carboxyphenoxy)nicotinic acid),dpea(1,2-di(4-pyridyl)ethane),dpey(1,2-di(4-pyridyl)ethylene),and zinc,cobalt,and nickel chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the triclinic system,space group P1.Compounds 1-3 show 2D layer structures.The catalytic activities in the Knoevenagel condensation reaction of these compounds were investigated.Compounds 1 and 2 exhibit effective catalytic activities in the Knoevenagel condensa-tion reaction at room temperature.For this reaction,various parameters were optimized,followed by the investiga-tion of the substrate scope.CCDC:2335676,1;2335677,2;2335678,3. 展开更多
关键词 coordination polymer dicarboxylic acid catalytic property Knoevenagel condensation reaction
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自密实混凝土及其在印度尼西亚的应用 被引量:8
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作者 王赞芝 江林雁 梁庆昌 《混凝土》 CAS CSCD 北大核心 2011年第6期108-113,共6页
自密实混凝土被称为近几十年中混凝土建筑技术最具革命性的发展。为了在中国进一步推广和更好地使用自密实混凝土,介绍了采用自密实混凝土改进混凝土结构性能(即耐久性与可靠性)的趋势以及自密实混凝土在印度尼西亚高层建筑和大跨桥梁... 自密实混凝土被称为近几十年中混凝土建筑技术最具革命性的发展。为了在中国进一步推广和更好地使用自密实混凝土,介绍了采用自密实混凝土改进混凝土结构性能(即耐久性与可靠性)的趋势以及自密实混凝土在印度尼西亚高层建筑和大跨桥梁中的应用情况。由于其高流动性,自密实混凝土适合于浇筑施工困难地方和复杂截面形式,尤其是钢筋布置很密的地方。采用自密实混凝土还能减少灌注大尺寸混凝土构件所需要的时间,例如建筑物的底部或基础的灌注。自密实混凝土也会减小施工现场由于混凝土振捣产生的噪音。随着掺合剂技术在使用新一代聚羧化物基超增塑剂方面的发展,现在自密实混凝土可以大规模商业化生产,并成功地在印度尼西亚和世界各地应用。 展开更多
关键词 自密实混凝土 高性能混凝土 羧化物基超增塑剂
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Synthesis of cyclic carbonates from epoxides and CO_2 in acetonitrile via the synergistic action of BMIMBr and electrogenerated magnesium 被引量:2
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作者 钮东方 吴志娟 +3 位作者 张历朴 杜荣斌 徐衡 张新胜 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第7期1076-1080,共5页
Using 1-butyl-3-methyl-imidazolium bromide (BM1MBr) as the supporting electrolyte and magne- sium as the sacrificial anode, a new and highly efficient electrochemically catalytic route was devel- oped for the synthe... Using 1-butyl-3-methyl-imidazolium bromide (BM1MBr) as the supporting electrolyte and magne- sium as the sacrificial anode, a new and highly efficient electrochemically catalytic route was devel- oped for the synthesis of cyclic carbonates from epoxides and CO2. Based on the cooperative action of BMIMBr and an electrogenerated magnesium salt obtained under a N2 atmosphere, CO2 reacted with a wide range of epoxides to readily generate cyclic carbonates in moderate to excellent yields under mild conditions. 展开更多
关键词 Electrogenerated magnesium saltlmidazolium bromideCarbon dioxideEpoxideCarboxylationCyclic carbonate
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Advances in Toxicology of Nε-(carboxymethyl)-lysine(CML) 被引量:1
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作者 张振华 孙建霞 +2 位作者 白卫滨 欧仕益 邱瑞霞 《Agricultural Science & Technology》 CAS 2013年第10期1403-1408,共6页
Advanced glycation end-products (AGEs) are products of non-enzymatic glycation of proteins, lipids or nucleic acids and other macromolecules. To be spe- cific, Nε-(carboxymethyl)-Iysine (CML) is one of the most... Advanced glycation end-products (AGEs) are products of non-enzymatic glycation of proteins, lipids or nucleic acids and other macromolecules. To be spe- cific, Nε-(carboxymethyl)-Iysine (CML) is one of the most important components of AGEs, which is wildly distributed in the body and can be formed in vivo or in food processing and heating processes. Previous studies have shown that CML is a ma- jor immunological epitope in AGEs and plays an important role in diabetes and its complications, as well as in the development and progression of aging. This review summarized recent advances in major source, toxicological hazard and control mea- sures of CML. 展开更多
关键词 Nε-(carboxymethyl)-Iysine (CML) Source TOXICOLOGY Control
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Cathode made of compacted silver nanoparticles for electrocatalytic carboxylation of 1-phenethyl bromide with CO_2 被引量:5
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作者 杨恒攀 吴腊霞 +1 位作者 王欢 陆嘉星 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第7期994-998,共5页
Silver nanoparticles prepared by the direct reduction of AgNO3 in aqueous solution were compacted into coins and used as the cathode for the electrocatalytic carboxylation of 1-phenethyl bromide with CO2. The influenc... Silver nanoparticles prepared by the direct reduction of AgNO3 in aqueous solution were compacted into coins and used as the cathode for the electrocatalytic carboxylation of 1-phenethyl bromide with CO2. The influences of the working electrode, charge, current density and temperature were investigated. Under optimized conditions, 98% yield of 2-phenylpropionic acid was obtained. The reaction was performed under very mild conditions and no added catalyst was required in the electrolyte. Yields that varied from moderate to excellent were also achieved with other benzyl bromides. This electrode has good stability and reusability, and the yield and selectivity of 2-phenylpropionic acid could be maintained during reuse for 10 times. 展开更多
关键词 ElectrocatalysisElectrocarboxylationCarbon dioxideBenzyl bromidesSilver nanoparticles
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Photo‐catalyzed sequential dearomatization/carboxylation of benzyl o‐halogenated aryl ether with CO_(2) leading to spirocyclic carboxylic acids
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作者 Yaping Yi Chanjuan Xi 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第7期1652-1656,共5页
Photo‐catalyzed tandem dearomatization/carboxylation of benzyl o‐halogenated aryl ether with CO_(2) was achieved,which affords spirocyclic carboxylic acids under mild conditions.The reaction has good functional grou... Photo‐catalyzed tandem dearomatization/carboxylation of benzyl o‐halogenated aryl ether with CO_(2) was achieved,which affords spirocyclic carboxylic acids under mild conditions.The reaction has good functional group tolerance with high yields.Mechanism studies indicate that the transformation was realized via intramolecular radical addition and nucleophilic addition. 展开更多
关键词 Photocatalysis Carbon dioxide DEAROMATIZATION CARBOXYLATION Spiro compounds
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Microwave-Assisted Decarboxylation of Sodium Oleate and Renewable Hydrocarbon Fuel Production 被引量:5
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作者 Wang Yunpu Liu Yuhuan +3 位作者 Ruan Rongsheng Wen Pingwei Wan Yiqin Zhang Jinsheng 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第3期19-27,共9页
The carboxyl terminal of sodium oleate has a stronger polarity than that of oleic acid;this terminal is more likely to be dipole polarized and ionically conductive in a microwave field.Sodium oleate was used as the mo... The carboxyl terminal of sodium oleate has a stronger polarity than that of oleic acid;this terminal is more likely to be dipole polarized and ionically conductive in a microwave field.Sodium oleate was used as the model compound to study the decarboxylation of oleic acid leading to hydrocarbon formation via microwave-assisted pyrolysis technology.The pyrolysis gas,liquid,and solid products were precisely analyzed to deduce the mechanism for decarboxylation of sodium oleate.Microwave energy was able to selectively heat the carboxyl terminal of sodium oleate.During decarboxylation,the double bond in the long hydrocarbon chain formed a p-πconjugated system with the carbanion intermediate.The resulting p-πconjugated system was more stable and beneficial to the pyrolysis reaction(decarboxylation,terminal allylation,isomerization,and aromatization).The physical properties of pyrolysis liquid were generally similar to those of diesel fuel,thereby demonstrating the possible use of microwaves for controlling the decarboxylation of sodium oleate in order to manufacture renewable hydrocarbon fuels. 展开更多
关键词 microwave radiation sodium oleate conjugated system DECARBOXYLATION HYDROCARBON
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Synthesis of Some Aminopicolinic Acids
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作者 Ramadan A. Bawa Ahela M. Beatty 《Journal of Chemistry and Chemical Engineering》 2012年第4期372-377,共6页
Some aminopicolinic acid derivatives have been synthesized and fully characterized. These pyridine derivatives were 4-aminopicolinic acid, 4-(4-aminophenylethynyl) picolinic acid and 4-(3-aminophenylethynyl) picol... Some aminopicolinic acid derivatives have been synthesized and fully characterized. These pyridine derivatives were 4-aminopicolinic acid, 4-(4-aminophenylethynyl) picolinic acid and 4-(3-aminophenylethynyl) picolinic acid. In addition to these compounds, other substituted picolinic acids were made throughout the synthetic paths. 展开更多
关键词 Aminopicolinic acid Sinogoshira coupling reaction synthetic paths.
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Visible‐light photoredox‐catalyzed carboxylation of benzyl halides with CO_(2):Mild and transition‐metal‐free
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作者 Ke Jing Ming‐Kai Wei +5 位作者 Si‐Shun Yan Li‐Li Liao Ya‐Nan Niu Shu‐Ping Luo Bo Yu Da‐Gang Yu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第7期1667-1673,共7页
The visible‐light photoredox‐catalyzed carboxylation of benzyl chlorides and bromides with CO_(2) has been reported.With inexpensive organic dyes as photocatalysts and amines as electron donors,this carboxylation pr... The visible‐light photoredox‐catalyzed carboxylation of benzyl chlorides and bromides with CO_(2) has been reported.With inexpensive organic dyes as photocatalysts and amines as electron donors,this carboxylation proceeds well in the absence of sensitive organometallic reagents,transition metal catalysts,or metallic reductants.A wide range of commercially available and inexpensive benzyl halides undergo such carboxylation to give valuable aryl acetic acids,including several pharmaceutical molecules and drug precursors,in moderate to high yields.Moreover,this reaction features mild reaction conditions(one atmospheric pressure of CO_(2) and room temperature),broad substrate scope,good functional group tolerance,easy scalability,and low catalyst loading,thus providing an efficient approach for the assembly of aryl acetic acids. 展开更多
关键词 Carbon dioxide Visible‐light photoredox catalysis CARBOXYLATION Aryl acetic acids Benzyl halides
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Permeabilization of Escherichia coli with ampicillin for a whole cell biocatalyst with enhanced glutamate decarboxylase activity 被引量:2
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作者 Weirui Zhao Sheng Hu +5 位作者 Jun Huang Piyu Ke Shanjing Yao Yinlin Lei Lehe Mei Jinbo Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第7期909-913,共5页
The activity of whole-cell biocatalysts is strongly compromised by the cell envelope, which is a permeability harrier against the diffusion of substrates and products. Although common chemical or physical permeahiliza... The activity of whole-cell biocatalysts is strongly compromised by the cell envelope, which is a permeability harrier against the diffusion of substrates and products. Although common chemical or physical permeahilization methods used in cultured cells enhance cell permeability, these methods inevitably add several extra processing steps after cell cultivation, as well as impede large scale processing. To increase membrane permeability and cell- bound glutamate decarboxylase (GAD) activity of recombinant Escherichia coil (BL21 (DE3)-pET28a-gadB) cells without the need for an additional permeabilization step, we investigated the permeabilizing effects of adding cell wall synthesis inhibitors or suffactants to the culture media. Ampidllin was the most effective at improving cell-bound GAD activity of the BL21 (DE3)-pET28a-gadB, although it decreased the cell biomass yield. The best permeabilization effect was observed using an ampicillin concentration of 5 pg. ml-1. Using this concentration, the cell hiomass did decrease by 40.58%, but the cell-bound GAD activity of BL21 (DE3)-pET28a-gadB and total cell-bound GAD activity per milliliter of culture was enhanced by 6.24- and 3.64-fold, respectively. Treatment ofBL21 (DE3)-pET28a-gadB cells with 5 tag.ml 1 ampicillin resulted in structural changes to the cell envelope, but did not substantially affect GAD expression. By entrapping the ampicillin-treated cells in an open pore gelation matrix, which is a polymer derived from polyvinyl alcohol (PVA), alginate, and boric acid, the transfor- mation rate of γ-aminobutyric acid (GABA) at the 10th cycle produced by immobilized and permeabilized cells remained 46% of the first cycle. GAD activity of the immobilized, permeabilized cells remained over 90% after 30 days of storage at 4 ℃. 展开更多
关键词 γ-Aminobutyric acidAmpicillinEscherichio. coilGlutamate decarboxylasePermeabilization
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Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems 被引量:8
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作者 Bernd Tieke 《Science China Chemistry》 SCIE EI CAS 2004年第4期311-319,共9页
The effects of temperature and multifunctional sodium carboxylate additives on the phase composition and morphology of calcium oxalate (CaOxa) crystals grown in silica gel system were systematically investigated using... The effects of temperature and multifunctional sodium carboxylate additives on the phase composition and morphology of calcium oxalate (CaOxa) crystals grown in silica gel system were systematically investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and Fourier-transform infrared spectra (FT-IR). The sodium carboxylates investigated include: monocarboxylate sodium acetate (NaAc), disodium tartrate (Na2tart), trisodium citrate (Na3cit), and the disodium salt of ethylenediaminetetraacetic acid (Na2edta). The temperature range was from 7°C to 67°C. The crystallization temperature affects the phase compositions, the growth rate, and the morphology of CaOxa. First, the logarithm of the percentage of calcium oxalate dihydrate (COD) formed at a certain temperature (T) is proportional to the reciprocal of temperature (1/T). Second, the weight of CaOxa crystals decreases as decreasing the temperature. At a given temperature, the ability of the sodium carboxylates to induce COD follows the order: Na2edta Na3cit Na2tart NaAc. Third, the multicarboxylates can decrease the surface area of calcium oxalate monohydrate (COM). It makes the edges and tips of COM crystals blunt and oval. All the three changes, an increase of the content of COD, a decrease of the weight of CaOxa crystals, and a decrease of the surface area of COM crystals, can inhibit the formation of CaOxa stones. These results support the clinical use of citrates and may be helpful in elucidating the mechanisms of the formation of CaOxa calculus. Keywords calcium oxalate - sodium carboxylate - gel - urinary calculi - crystallization - biomineralization 展开更多
关键词 calcium oxalate sodium carboxylate GEL urinary calculi CRYSTALLIZATION BIOMINERALIZATION
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Mechanism of palladium-catalyzed decarboxylative cross-coupling between cyanoacetate salts and aryl halides 被引量:5
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作者 JIANG YuanYe FU Yao LIU Lei 《Science China Chemistry》 SCIE EI CAS 2012年第10期2057-2062,共6页
Recently we reported Pd-catalyzed decarboxylative cross-coupling of cyanoacetate salts with aryl halides and triflates. This reaction shows good functional group tolerance and is useful for the synthesis of-aryl nitri... Recently we reported Pd-catalyzed decarboxylative cross-coupling of cyanoacetate salts with aryl halides and triflates. This reaction shows good functional group tolerance and is useful for the synthesis of-aryl nitriles. To elucidate the mechanism for this reaction, we now carry out a density functional theory study on the cross-coupling of potassium cyanoacetate with bromobenzene. Our results show that the decarboxylation transition state involving the interaction of Pd with the-carbon atom has a very high energy barrier of +34.5 kcal/mol and therefore, must be excluded. Decarboxylation of free ion (or tight-ion-pair) also causes a high energy increase and should be ruled out. Thus the most favored decarboxylation mechanism corresponds to a transition state in which Pd interacts with the cyano nitrogen. The energy profile of the whole catalytic cycle shows that decarboxylation is the rate-determining step. The total energy barrier is +27.5 kcal/mol, which is comprised of two parts, i.e. the energy barrier for decarboxylation and the energy cost for transmetallation. 展开更多
关键词 PALLADIUM catalytic DECARBOXYLATION MECHANISM density functional theory
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Synthesis of aziridines by visible-light induced decarboxylative cyclization of N-aryl glycines and diazo compounds
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作者 Yong Liu Xichang Dong +1 位作者 Guojun Deng Lei Zhou 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第2期199-202,共4页
A visible-light induced decarboxylative aza-Darzens reaction between N-aryl glycines and diazo compounds was developed, which affords various mono-substituted aziridines in good yields.
关键词 visible light diazo compound DECARBOXYLATION aza-Darzens reaction
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Transition metal-catalyzed decarboxylative cross-coupling reactions 被引量:13
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作者 SHANG Rui LIU Lei 《Science China Chemistry》 SCIE EI CAS 2011年第11期1670-1687,共18页
Transition metal-catalyzed decarboxylative cross-coupling reactions have recently emerged as a new and important category of organic transformations that find versatile applications in the construction of carbon-carbo... Transition metal-catalyzed decarboxylative cross-coupling reactions have recently emerged as a new and important category of organic transformations that find versatile applications in the construction of carbon-carbon and carbon-heteroatom bonds. The use of relatively cheap and stable carboxylic acids to replace organometallic reagents enables the decarboxylative cross-coupling reactions to proceed with good selectivities and functional group tolerance. In the present review we summarize the various types of decarboxylative cross-coupling reactions catalyzed by different transition metal complexes. The scope and applications of these reactions are described. The challenges and opportunities in the field are discussed. 展开更多
关键词 DECARBOXYLATION cross-coupling reaction transition metal CATALYSIS organic synthesis
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