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TOXICITY OF TWO HERBICIDES 2,4-D DIMETHYLAMINE AND BENSULFURON METHYL TO RICE FIELD CHIRONOMUS KIIENSIS (TOKUNAGA) (DIPTERA:CHIRONOMIDAE)
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作者 Al-Shami S A Che Salmah M R +2 位作者 Siti Azizah M N Abu Hassan A Azmi M 《湿地科学》 CSCD 2006年第4期241-246,共6页
关键词 CHIRONOMIDAE Chironomus kiiensis HERBICIDES 2 4-D dimethylamine Bensulfuron methyl
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Crystal Structure of Dimethylamine 3,5-Dinitrobenzoic Acid Organic Adduct
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作者 ZHU Jun ZHANG Yun CHEN Hao CHE Yun-Xia ZHENG Ji-Min 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第8期1011-1013,共3页
The title adduct (C9H11N3O6, Mr= 257.21) was synthesized and it crystallizes in orthorhombic, space group P212121 with a = 5.8835(19), b =9.517(3), c = 20.399(6) A, V= 1142.2(6) ,A^3 Z = 4, Dc= 1.496 g/cm^3... The title adduct (C9H11N3O6, Mr= 257.21) was synthesized and it crystallizes in orthorhombic, space group P212121 with a = 5.8835(19), b =9.517(3), c = 20.399(6) A, V= 1142.2(6) ,A^3 Z = 4, Dc= 1.496 g/cm^3, F(000) = 536,μ(MoKα) = 0.128 mm^-1, the final R = 0.0396 and wR = 0.0800 for 1047 observed reflections with I 〉 2σ(I). The compound is a 1:1 adduct of dimethylamine and 3,5-dinitrobenzoic acid which are linked by hydrogen bonds to form a two-dimensional network. The dimethylamine is protonated at the nitrogen atom with the proton from the carboxyl of 3,5- dinitrobenzoic acid. 展开更多
关键词 dimethylamine 3 5-dinitrobenzoic acid hydrogen bond crystal structure nonlinear optical
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Synthesis and Crystal Structure Analysis of 2-(3,5-Di-tert-butyl-2-hydroxyphenyl)-2-(3,4- dimethylphenyl) Acetic Acid Dimethylamine Salt
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作者 程杰 成昌梅 +3 位作者 何娟 尚培华 王如骥 赵玉芬 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第4期414-418,共5页
A new compound 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-2-(3,4-dimethylphenyl) acetic acid dimethylamine salt ([NH2(CH3)2][C24H31O3]) was synthesized and structurally determined. It is of monoclinic system, space... A new compound 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-2-(3,4-dimethylphenyl) acetic acid dimethylamine salt ([NH2(CH3)2][C24H31O3]) was synthesized and structurally determined. It is of monoclinic system, space group P21/c with a = 14.731(2), b = 10.1185(10), c = 17.065(2) A^°, β = 98.293(10)° ,Z = 4, V = 2517.0(6)A^°^3, Dc = 1.091 g/cm^3, F(000) = 904 and Mr= 413.58. The dihedral angle defined by two benzene rings is 98.23°. 展开更多
关键词 2-(3 5-di-tcrt-butyl-2-hydraxyphenyl)-2-(3 4-dimethylphenyl) acetic acid dimethylamine salt synthesis X-ray diffraction crystal structure
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Use of Cucurbit [6] Uril as a Modifier in the Electrochemical Determination of Antitumor Platinum (II) Complex: <i>Trans</i>-[PtCl<sub>2</sub>(Dimethylamine) (Isopropylamine)]. Application to Biological Samples
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作者 Carmen S. H. Domínguez Pedro Hernández 《American Journal of Analytical Chemistry》 2013年第6期314-322,共9页
A square wave voltammetry (DPV) method for trans-Pt[Cl2(Dimethylamine)(isopropylamine)] determination is developed. To this end, all the chemical and instrumental variables affecting the determination of trans-Pt[Cl2(... A square wave voltammetry (DPV) method for trans-Pt[Cl2(Dimethylamine)(isopropylamine)] determination is developed. To this end, all the chemical and instrumental variables affecting the determination of trans-Pt[Cl2(Dimethylamine) (isopropylamine)] are optimized. From studies of the mechanisms governing the electrochemical response of trans-Pt[Cl2(Dimethylamine)(isopropylamine)], it was concluded that it was an electrochemically reversible system with an adsorptive oxidation phenomenon. Under optimal conditions, the variation of analytical signal (Ip) with trans-Pt[Cl2(Dimethylamine)(isopropylamine)] concentration was linear in the 0.05 μg·mL-1 to 10 μg·mL-1 range, with a LOD 91 μg·mL-1 of and a LOQ of 303 μg·mL-1, a RSD 1.10% and Er 0.72%. The optimized method was applied to the determination of trans-Pt[Cl2(Dimethylamine)(isopropylamine)] in biological fluids, in human urine and synthetic urine. 展开更多
关键词 Trans-[PtCl2(dimethylamine)(Isopropylamine)] Differential Pulse VOLTAMMETRY (DPV) Square Wave VOLTAMMETRY (SWV) Biological Fluids Human Urine
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Factors influencing the photodegradation of Nnitrosodimethylamine in drinking water
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作者 Bingbing XU Zhonglin CHEN +2 位作者 Fei QI Jimin SHEN Fengchang WU 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2009年第1期91-97,共7页
In order to provide basic data for practical application,photodegradation experiment of Nnitrosodimethylamine(NDMA)in aqueous solution was carried out with a low-pressure Hg lamp.Effects of the initial concentration o... In order to provide basic data for practical application,photodegradation experiment of Nnitrosodimethylamine(NDMA)in aqueous solution was carried out with a low-pressure Hg lamp.Effects of the initial concentration of NDMA,solution pH,dissolved oxygen,and the presence of humic acid on NDMA photodegradation were investigated.NDMA at various initial concentrations selected in this study was almost completely photodegraded by UV irradiation within 20 min,except that at 1.07 mmol/L,NDMA could be photodegraded almost completely in the acidic and neutral solutions,while the removal efficiency decreased remarkably in the alkaline solution.Dissolved oxygen enhanced the NDMA photodegradation,and the presence of humic acid inhibited the degradation of NDMA.Depending on the initial concentration of NDMA,NDMA photodegradation by UV obeyed the pseudo-first-order kinetics.Dimethylamine,nitrite,and nitrate were detected as the photodegradation products of NDMA.^(1)O_(2) was found to be the reactive oxygen species present in the NDMA photodegradation process by UV,based on the inhibiting experiments using tert-butanol and sodium azide. 展开更多
关键词 N-nitrosodimethylamine(NDMA) ultraviolet irradiation degradation kinetic dimethylamine photodegradation product
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Capability of cation exchange technology to remove proven N-nitrosodimethylamine precursors
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作者 Shixiang Li Xulan Zhang +5 位作者 Er Bei Huihui Yue Pengfei Lin Jun Wang Xiaojian Zhang Chao Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第8期331-339,共9页
N-nitrosodimethylamine(NDMA) precursors consist of a positively charged dimethylamine group and a non-polar moiety, which inspired us to develop a targeted cation exchange technology to remove NDMA precursors. In th... N-nitrosodimethylamine(NDMA) precursors consist of a positively charged dimethylamine group and a non-polar moiety, which inspired us to develop a targeted cation exchange technology to remove NDMA precursors. In this study, we tested the removal of two representative NDMA precursors, dimethylamine(DMA) and ranitidine(RNTD), by strong acidic cation exchange resin. The results showed that pH greatly affected the exchange efficiency, with high removal(DMA 〉 78% and RNTD 〉 94%) observed at pH 〈 pk_a-1 when the molar ratio of exchange capacity to precursor was 4. The exchange order was obtained as follows: Ca^(2+)〉 Mg^(2+)〉 RNTD~+〉 K~+〉 DMA~+〉 NH_4~+〉 Na~+. The partition coefficient of DMA~+to Na~+was 1.41 ± 0.26, while that of RNTD~+to Na~+was 12.1 ± 1.9. The pseudo second-order equation fitted the cation exchange kinetics well. Bivalent inorganic cations such as Ca^(2+)were found to have a notable effect on NA precursor removal in softening column test. Besides DMA and RNTD, cation exchange process also worked well for removing other 7 model NDMA precursors. Overall, NDMA precursor removal can be an added benefit of making use of cation exchange water softening processes. 展开更多
关键词 Ion exchange Cation exchange resin N-nitrosamine precursors dimethylamine Ranitidine
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Infrared spectroscopic probing of dimethylamine clusters in an Ar matrix
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作者 Siyang Li Henrik G.Kjaergaard Lin Du 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第2期51-59,共9页
Amines have many atmospheric sources and their clusters play an important role in aerosol nucleation processes. Clusters of a typical amine, dimethylamine(DMA), of different sizes were measured with matrix isolation... Amines have many atmospheric sources and their clusters play an important role in aerosol nucleation processes. Clusters of a typical amine, dimethylamine(DMA), of different sizes were measured with matrix isolation IR(infrared) and NIR(near infrared)spectroscopy. The NIR vibrations are more separated and therefore it is easier to distinguish different sizes of clusters in this region. The DMA clusters, up to DMA tetramer, have been optimized using density functional methods, and the geometries, binding energies and thermodynamic properties of DMA clusters were obtained. The computed frequencies and intensities of NH-stretching vibrations in the DMA clusters were used to interpret the experimental spectra. We have identified the fundamental transitions of the bonded NH-stretching vibration and the first overtone transitions of the bonded and free NH-stretching vibration in the DMA clusters. Based on the changes in vibrational intensities during the annealing processes, the growth of clusters was clearly observed. The results of annealing processes indicate that DMA molecules tend to form larger clusters with lower energies under matrix temperatures, which is also supported by the calculated reaction energies of cluster formation. 展开更多
关键词 Matrix isolation Infrared(IR) spectroscopy dimethylamine clusters Aerosol nucleation
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An alternate aqueous phase synthesis of the Pt3Co/C catalyst towards efficient oxygen reduction reaction 被引量:2
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作者 Jinjing Huang Chen Ding +2 位作者 Yongqiang Yang Gang Liu Wen-Bin Cai 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第12期1895-1903,共9页
Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction(ORR)for the application in low temperature fuel cells and beyond,thus their facile and green synthesis is h... Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction(ORR)for the application in low temperature fuel cells and beyond,thus their facile and green synthesis is highly demanded.Herein we initially report an alternate aqueous phase one-pot synthesis of such catalysts(containing nominally ca.20 wt.%Pt)based on dimethylamine borane(DMAB)reduction.The as-obtained electrocatalyst(denoted as Pt3Co/C-DMAB)is compared with the ones obtained by NaBH4 and N2H4·H2O reduction(denoted as Pt3Co/C-NaBH4 and Pt3Co/C-N2H4·H2O,respectively)as well as a commercial Pt/C,in terms of the structure and electrocatalytic property.It turns out that Pt3Co/C-DMAB exhibits the highest ORR performance among all the tested samples in an O2-saturated 0.1 mol/L HClO4,with the mass activity(specific activity)ca.4(6)times as large as that for Pt/C.After 10000 cycles of the accelerated degradation test,the half-wave potential for ORR on Pt3Co/C-DMAB decreases only by 4 mV,in contrast to 24 mV for that on Pt/C.Pt3Co/C-NaBH4 or Pt3Co/C-N2H4·H2O shows a specific activity comparable to that for Pt3Co/C-DMAB,but a mass activity similar to that for Pt/C.ICP-AES,TEM,XRD and XPS characterizations indicate that Pt3Co nanoparticles are well-dispersed and alloyed with a mean particle size of ca.3.4±0.4 nm,contributing to the prominent electrocatalytic performance of Pt3Co/C-DMAB.This simple aqueous synthetic route may provide an alternate opportunity for developing efficient practical electrocatalysts for ORR. 展开更多
关键词 ORR electrocatalyst Pt–Co alloy Aqueous phase synthesis dimethylamine borane Structure and property
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Preparation and Characterization of Single Crystals of MAPO-43 Molecular Sieve 被引量:1
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作者 JianJunLI GuoDongLI ChunYuXI JieShengCHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第5期615-618,共4页
Large single crystals of MAPO-43 molecular sieve have been synthesized hydrothermally using dimethylamine as the template. The typical molar composition of the starting mixture was 1.0P2O5 : 0.54Al2O3: 0.8MgO: 8.5CH3... Large single crystals of MAPO-43 molecular sieve have been synthesized hydrothermally using dimethylamine as the template. The typical molar composition of the starting mixture was 1.0P2O5 : 0.54Al2O3: 0.8MgO: 8.5CH3NHCH3: 0.68HF: 180H2O. The sample was characterized by XRD, TGA, DTA and IR. 展开更多
关键词 MAPO-43 single crystal dimethylamine hydrothermal synthesis.
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Cationized Melamine-formaldehyde Resin for Improving the Wet Strength of Paper
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作者 HuaShan Wang LuMing Yang +3 位作者 YuFang Liu KaiWen Mou YiZe Li RuiTao Cha 《Paper And Biomaterials》 2016年第1期56-62,共7页
In this work, melamine-formaldehyde resin was cationized by adding modifiers so that the fibers closely bonded to improve their usability and the wet strength of paper was greatly improved. Triethanolamine and dimethy... In this work, melamine-formaldehyde resin was cationized by adding modifiers so that the fibers closely bonded to improve their usability and the wet strength of paper was greatly improved. Triethanolamine and dimethylamine were added to modify the melamine-formaldehyde resin,respectively.The mechanism of the cationized resin was explored and the possible chemical reactions were deduced. It was concluded that,with the use of triethanolamine,the most optimum product was obtained by hydroxymethylation for 30 min with a temperature of 85℃ and p H of 9. 0 where n( melamine) ∶ n( formaldehyde) ∶ n( methanol) ∶ n( triethanolamine) was 100 ∶ 330 ∶ 450 ∶ 15. With the combined use of dimethylamine and methanol,the optimal product was acquired by condensation for 30 min at a temperature of 50℃ and p H of 2. 0 at melamine, formaldehyde, methanol, and dimethylamine molar ratio of100∶ 330∶ 350∶ 20. With the only use of dimethylamine,the optimal product was obtained by condensation at melamine,formaldehyde,dimethylamine molar ratio of 100∶ 330∶ 10. The wet tensile strength of fruit-bagging paper was improved by adding cationized melamine-formaldehyde resin. The zeta potential,charge density,and conductivity of the melamine-formaldehyde resin were also studied. 展开更多
关键词 cationized melamine-formaldehyde resin wet tensile strength fruit-bagging paper TRIETHANOLAMINE dimethylamine
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Adsorptive Removal of Heavy Metals from Aqueous Solution with Environmental Friendly Material—Exhausted Tea Leaves
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作者 Bindra Shrestha Jagjit Kour Kedar Nath Ghimire 《Advances in Chemical Engineering and Science》 2016年第4期525-540,共16页
In this study adsorptive removal of Pb(II) and Cu(II) from aqueous solution by using environmental friendly natural polymers present in exhausted tea leaves has been studied. The biosorbent was modified with dimethyla... In this study adsorptive removal of Pb(II) and Cu(II) from aqueous solution by using environmental friendly natural polymers present in exhausted tea leaves has been studied. The biosorbent was modified with dimethylamine to introduce N-functional groups on the surface of adsorbent. The modified adsorbent was characterized by elemental analysis, zeta potential analysis, SEM, DRFTIR, XRD and TG/DTA analysis to conform the modification. Adsorption capacity of the adsorbent was determined as the function of pH of the solution, initial concentration of the solution and contact time. The adsorption experiments were performed using batch experiments. The maximum adsorption capacities of the adsorbent were found to be 91.68 and 71.20 mg/g for Pb(II) and Cu(II), respectively. To minimize the process cost, regeneration of the biosorbent and recovery of metal ions was explored by desorption study. The results indicate that the adsorbent holds great potential for the sequestration of Pb(II) and Cu(II) from their aqueous solution. Hence the modified exhausted tea leaves (MTL) have been investigated as a new cost effective and efficient biosorbent for removal of Pb(II) and Cu(II) from their aqueous solution. 展开更多
关键词 Natural Polymer BIOSORBENT Heavy Metals dimethylamine Exhausted Tea Leaves
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