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Effects of Coagulation and Ozonation Pretreatments on Biochemical Treatment of Fluid Catalytic Cracking Wastewater
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作者 Ibrah Landi Ali Lu Jun 《Journal of Environmental Protection》 2024年第2期156-172,共17页
Fluid catalytic cracking (FCC) salty wastewaters, containing quaternary ammonium compounds (QACs), are very difficult to treat by biochemical process. Anoxic/oxic (A/O) biochemical system, based on nitrification and d... Fluid catalytic cracking (FCC) salty wastewaters, containing quaternary ammonium compounds (QACs), are very difficult to treat by biochemical process. Anoxic/oxic (A/O) biochemical system, based on nitrification and denitrification reactions, was used to assess their possible biodegradation. Because of the negative effects of high salt concentration (3%), heavy metals and toxic organic matter on microorganisms’ activities, some techniques consisting of dilution, coagulation and flocculation, and ozonation pretreatments, were gradually tested to evaluate chemical oxygen demand (COD), ammonia-nitrogen (ammonia-N) and total nitrogen (TN) removal rates. In this process of FCC wastewater, starting with university-domesticated sludge, the ammonia-N and TN removal rates were worst. However, when using domesticated SBR’s sludge and operating with five-fold daily diluted influent (thus reducing salt concentration), the ammonia-N removal reached about 57% while the TN removal rate was less than 37% meaning an amelioration of the nitrification process. However, by reducing the dilution factors, these results were inflected after some days of operation, with ammonia-N removal decreasing and TN barely removed meaning a poor nitrification. Even by reducing heavy metals concentration with coagulation/flocculation process, the results never changed. Thereafter, by using ozonation pre-treatment to degrade the detected organic matter of di-tert-butylphenol and certain isoparaffins, COD, ammonia-N and TN removal rates reached 92%, 62% and 61%, respectively. These results showed that the activities of the microorganisms were increased, thus indicating a net denitrification and nitrification reactions improvement. 展开更多
关键词 Ammonia-n Anoxic and oxic (A/o) Reactor Coagulation and Sedimentation FCC Wastewater ozone Total nitrogen (Tn)
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Solvent-Free Synthesis of 5-Alkenyl-2,2-butylidene-1, 3-dioxane-4,6-diones under Ultrasonic Irradiation with o-Phthalimide-N-Sulfonic Acid as Catalyst 被引量:1
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作者 Chunhua Lin Zhaohui Xu Weilin Liao 《International Journal of Organic Chemistry》 2013年第4期275-279,共5页
5-Alkenyl-2,2-butylidene-1,3-dioxane-4,6-diones were synthesized by the Knoevenagel condensation reaction of aromatic aldehydes with 2,2-butylidene-1,3-dioxane-4,6-dione using o-phthalimide-N-sulfonic acid as catalyst... 5-Alkenyl-2,2-butylidene-1,3-dioxane-4,6-diones were synthesized by the Knoevenagel condensation reaction of aromatic aldehydes with 2,2-butylidene-1,3-dioxane-4,6-dione using o-phthalimide-N-sulfonic acid as catalyst, without solvent under ultrasonic irradiation. The present method has some notable advantages such as mild reaction conditions, short reaction times, less catalyst dosage and high yields with the green aspects by avoiding toxic catalysts and solvents. Further, the catalyst can be reused for five times without any noticeable decrease in the catalytic activity. 展开更多
关键词 o-Phthalimide-n-Sulfonicacid 5-Alkenyl-2 2-butylidene-1 3-dioxane-4 6-diones Aromatic Aldehydes Knoevenagel Condensation
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Double-Doped Carbon-Based Electrodes with Nitrogen and Oxygen to Boost the Areal Capacity of Zinc-Bromine Flow Batteries
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作者 Xiaoyun Sun Deren Wang +4 位作者 Haochen Hu Xin Wei Lin Meng Zhongshan Ren Sensen Li 《Transactions of Tianjin University》 EI CAS 2024年第1期74-89,共16页
Ensuring a stable power output from renewable energy sources,such as wind and solar energy,depends on the development of large-scale and long-duration energy storage devices.Zinc–bromine fl ow batteries(ZBFBs)have em... Ensuring a stable power output from renewable energy sources,such as wind and solar energy,depends on the development of large-scale and long-duration energy storage devices.Zinc–bromine fl ow batteries(ZBFBs)have emerged as cost-eff ective and high-energy-density solutions,replacing expensive all-vanadium fl ow batteries.However,uneven Zn deposition during charging results in the formation of problematic Zn dendrites,leading to mass transport polarization and self-discharge.Stable Zn plating and stripping are essential for the successful operation of high-areal-capacity ZBFBs.In this study,we successfully synthesized nitrogen and oxygen co-doped functional carbon felt(NOCF4)electrode through the oxidative polymerization of dopamine,followed by calcination under ambient conditions.The NOCF4 electrode eff ectively facilitates effi cient“shuttle deposition”of Zn during charging,signifi cantly enhancing the areal capacity of the electrode.Remarkably,ZBFBs utilizing NOCF4 as the anode material exhibited stable cycling performance for 40 cycles(approximately 240 h)at an areal capacity of 60 mA h/cm^(2).Even at a high areal capacity of 130 mA h/cm^(2),an impressive energy effi ciency of 76.98%was achieved.These fi ndings provide a promising pathway for the development of high-areal-capacity ZBFBs for advanced energy storage systems. 展开更多
关键词 Zinc-bromine fl ow batteries n o co-doping Areal capacity Shuttle deposition Zinc dendrite
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Synthesis of thiopyrano[4″,3″:4′,5′]pyrido[3′,2′:4,5]furo[3,2-d]pyrimidines 被引量:2
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作者 Essam Kh. Ahmed Mohamed A. Ameen 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第6期669-673,共5页
Reactions of the 6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrile derivative 1 withα-halo-carbonyl compounds gave the ortho-substituted intermediates 2a-c which were converted into furo[2,3-b]thiopyrano[4,3-d]pyrid... Reactions of the 6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrile derivative 1 withα-halo-carbonyl compounds gave the ortho-substituted intermediates 2a-c which were converted into furo[2,3-b]thiopyrano[4,3-d]pyridines 3a-c by fusion of a furan moiety under basic conditions.Further cyclization of 3a-c led to a fusion of a pyrimidine ring,yielding the tetracyclic products 6,7 and 8.In addition,condensation of 6 with various aromatic aldehydes afforded the corresponding imines 9a,b.Mannich reaction of 7 gave products 10a,b. 展开更多
关键词 S n-HETERoCYCLES S n o-Heterocyles Furo[2 3-b]thiopyrano[4 3-d]pyridine Thiopyranopyridofuropyrimidines
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CpOGA^(D298N)与核心链霉亲和素Stv13融合表达用于检测蛋白质O⁃GlcNAc修饰
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作者 黎先感 杨明 +4 位作者 鲁莹 李玲 马骞 李静 张连文 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2024年第4期513-519,共7页
氧连接的β-N-乙酰葡萄糖胺修饰(O-GlcNAc修饰)是一种发生在蛋白质丝氨酸、苏氨酸羟基上的一种动态、可逆的翻译后修饰。O-GlcNAc修饰在细胞的许多关键过程中发挥重要作用,也是研究阿尔茨海默病和糖尿病等的重要途径,但是常用于O-GlcNA... 氧连接的β-N-乙酰葡萄糖胺修饰(O-GlcNAc修饰)是一种发生在蛋白质丝氨酸、苏氨酸羟基上的一种动态、可逆的翻译后修饰。O-GlcNAc修饰在细胞的许多关键过程中发挥重要作用,也是研究阿尔茨海默病和糖尿病等的重要途径,但是常用于O-GlcNAc蛋白检测的抗体特异性或者检测分子量范围仍存在问题且耗时(~36 h)过长,对后续研究造成困扰。在本研究中,我们设计构建了产气荚膜梭菌OGA(O-GlcNAcase)突变体(CpOGA^(D298N))与核心链霉亲和素Stv13融合表达质粒pET28a-CpOGA^(D298N)-Stv13。将质粒pET28a-CpOGA^(D298N)-Stv13转化到大肠杆菌BL21(DE3)中进行诱导表达,获得了融合蛋白质CpOGA^(D298N)-Stv13。通过CpOGA^(D298N)特异性结合O-GlcNAc的能力及生物素-亲和素特异性亲和作用,设计了Far-Western blot(Far-WB)用于检测蛋白质O-GlcNAc修饰,利用sOGT(short form O-GlcNAc transferase)、去O-GlcNAc修饰sOGT、细胞裂解液样本及人肝细胞核因子1A(hepatocyte fuclear factor 1A,HNF1A)对该方法进行验证。本研究成功构建了一种蛋白质O-GlcNAc修饰检测方法,耗时相对O-GlcNAc特异性抗体缩短至5~7 h,丰富了蛋白质O-GlcNAc修饰的检测方法,为其后续研究奠定了基础。 展开更多
关键词 氧连接的β-n-乙酰葡萄糖胺修饰 CpoGA^(D298n)-Stv13 生物素 Far-Western blot
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Synthesis, Spectroscopy and X-Ray Crystal Structure of 9-Methyl-3-Thiophen-2-Yl-Thieno [3, 2-e] [1, 2, 4] Triazolo [4, 3-c] Pyrimidine-8-Carboxylic Acid Ethyl Ester
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作者 Nikhath Fathima Mohamed Ziaulla +3 位作者 Afshan Banu Shridhar Ishwar Panchamukhi Imtiyaz Ahmed Khazi Noor Shahina Begum 《American Journal of Analytical Chemistry》 2011年第3期371-375,共5页
The Preparation of 9-Methyl-3-thiophen-2-yl-thieno [3, 2-e] [1, 2, 4] triazolo [4, 3-c] pyrimi-dine-8-carboxylic acid ethyl ester is described. Elemental analysis, IR spectrum, 1H NMR, 13C NMR and X-ray crystal struct... The Preparation of 9-Methyl-3-thiophen-2-yl-thieno [3, 2-e] [1, 2, 4] triazolo [4, 3-c] pyrimi-dine-8-carboxylic acid ethyl ester is described. Elemental analysis, IR spectrum, 1H NMR, 13C NMR and X-ray crystal structure analyses were carried out to determine the composition and molecular structure of the title compound. There are two independent molecules in the asymmetric unit exhibiting intermolecular C-H…N, C-H…O interactions with additional π-π interaction that further helps in stabilizing the supramolecular structure. The results showed that the proposed method for synthesis is simple, precise and accurate which was further confirmed by crystal structure analysis. 展开更多
关键词 Thieno-Triazolo-Pyrimidine Derivative Characterization X-Ray Crystallographic Analysis C-H…n C-H…o and π-π Weak Interactions
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Facile Fabrication of Hierarchical Porous N/O Functionalized Carbon Derived from Blighted Grains Towards Electrochemical Capacitors 被引量:1
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作者 Chen Zhiyi Wang Zhengluo +3 位作者 Zhao Zhiwei Sun Xuan Hou Linrui Yuan Changzhou 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第4期639-647,共9页
The hierarchical porous N/O co-functionalized carbon(HPNOC)was scalably prepared by using the lowcost and renewable blighted grains as the raw material coupled with mild KHCO_3 activation for electrochemical capacitor... The hierarchical porous N/O co-functionalized carbon(HPNOC)was scalably prepared by using the lowcost and renewable blighted grains as the raw material coupled with mild KHCO_3 activation for electrochemical capacitors(ECs).The elemental N was in situ doped in the obtained HPNOC without any N-containing additives.Remarkably,the obtained HPNOC was endowed with a large specific surface area(about 2 624m^2·g^(-1)),high pore volume(about 1.35cm^3·g^(-1)),as well as high-content N/O functionalization(about 1.9%(in atom)N and about 10.2%(in atom)O.Furthermore,the as-resulted HPNOC electrode with a high mass loading of 5mg·cm^(-2 )exhibited competitive gravimetric capacitances of about 373.6F·g^(-1 )at 0.5A·g^(-1),and even about 260.4F·g^(-1 )at a high rate of 10A·g^(-1);superior capacitance retention of about 98.8%at 1A·g^(-1 )over 10 000consecutive cycles;and high specific energy of about 9.6W·h·kg^(-1 )at a power of 500W·kg^(-1),when evaluated as a promising electrode in 6mol KOH for advanced electrochemical supercapacitors.More encouragingly,the green synthetic strategy we developed holds a huge promise in generalizing for other biomass-derived carbon materials for versatile energy-related applications. 展开更多
关键词 hierarchical porous carbon KHCo3 activation n/o functionalization electrochemical supercapacitors eco-friendly fabrication
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Reactivity Ratios for Microemulsion Copolymeriration of N-butyl Maleimide and Styrene 被引量:1
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作者 You Liang ZHAO Hua Ming LI Peng Sheng LIU (College of Chemistry and Chemical Engineering, Xiangtan University. Xiangtan 411105) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第5期451-452,共2页
The oil-in-water microemulsion containing N-butyl maleimide(NBMI. M_1) and styrene(St, M_2) was prepared. The complexation properties of NBMI and St in microemulsion were investigated by means of 1H-NMR. With the part... The oil-in-water microemulsion containing N-butyl maleimide(NBMI. M_1) and styrene(St, M_2) was prepared. The complexation properties of NBMI and St in microemulsion were investigated by means of 1H-NMR. With the participation of charge-transfer complex(CTC). four reactivity ratios and the relative reactivity of free monomers and CTC were obtained. The result was compared with that measured by Mayo-Lewis method. 展开更多
关键词 n-Butyl maleimide STYREnE charge-transfer complex o/W microemulsion copolymeriation reactivity fation.
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DFT Study on Intermolecular Cleavage Reaction of N-(2-Hydroxyphenyl)-phthalamic Acid
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作者 ZHAO Chu-feng TANG Ming-sheng WANG Hong-ming WEI Dong-hui ZHAO Jing ZHANG Shou-ren CAO Shu-xia 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第6期790-792,共3页
The reaction mechanisms of intermolecular cleavage reaction of N-(2-hydroxyphenyl)-phthalamic acid were studied via the density functional theory(DFT). All geometries of the reactant, transition states, and produc... The reaction mechanisms of intermolecular cleavage reaction of N-(2-hydroxyphenyl)-phthalamic acid were studied via the density functional theory(DFT). All geometries of the reactant, transition states, and products were optimized at the B3LYP/6-31G(d, p) level. Vibration analysis was carried out to confirm its identity as transitions' structure, and the intrinsic reaction coordinate method(IRC) was used to search the minimum energy path. Two possible reaction channels are reported in this article. The calculated results indicate that O-cyclization reaction channel has the lower activation barrier, and therefore, it occurs more easier than the other. 展开更多
关键词 Intermolecular decomposition reaction Density functional theory(DFT) o-Cyclization n-Cyclization n-(2-Hydroxyphenyl)-phthalamic acid
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表面In掺杂TiO2的N719/TiO2-Inx%/FTO薄膜电极的光电转换效率 被引量:6
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作者 程辉 姚江宏 曹亚安 《物理化学学报》 SCIE CAS CSCD 北大核心 2012年第11期2632-2640,共9页
采用溶胶-凝胶法制备出In表面修饰的TiO2(TiO2-Inx%)纳米粒子,x%代表在In掺杂的TiO2样品中In3+与In3+和Ti4+离子摩尔百分含量.利用二(四丁基铵)顺式-双(异硫氰基)双(2,2-联吡啶-4,4-二羧酸)钌(II)(N719)作为敏化剂,制备出N719/TiO2/FTO... 采用溶胶-凝胶法制备出In表面修饰的TiO2(TiO2-Inx%)纳米粒子,x%代表在In掺杂的TiO2样品中In3+与In3+和Ti4+离子摩尔百分含量.利用二(四丁基铵)顺式-双(异硫氰基)双(2,2-联吡啶-4,4-二羧酸)钌(II)(N719)作为敏化剂,制备出N719/TiO2/FTO(氟掺杂锡氧化物)和N719/TiO2-Inx%/FTO染料敏化薄膜电极.光电转换效率实验表明,在薄膜电极+0.5mol.L-1LiI+0.05mol.L-1I2的三甲氧基丙腈(MPN)溶液+Pt光电池体系中,N719/TiO2-Inx%/FTO薄膜电极的光电转换效率均高于N719/TiO2/FTO,其中N719/TiO2-In0.1%/FTO的光电转换效率比N719/TiO2/FTO提高了20%.利用X射线衍射(XRD)、X射线光电子能谱(XPS)、漫反射吸收光谱(DRS)、荧光(PL)光谱和表面光电流作用谱确定了TiO2-Inx%样品中In3+离子的存在方式和能带结构;利用表面光电流作用谱研究了N719/TiO2-Inx%/FTO薄膜电极的光致界面电荷转移过程.结果表明,In3+离子在TiO2表面形成O-In-Cln(n=1,2)物种,该物种的表面态能级位于导带下0.3eV处;在光电流产生过程中,O-In-Cln(n=1,2)表面态能级有效地抑制了光生载流子在TiO2-Inx%层的复合,促进了阳极光电流的增加,从而导致N719/TiO2-Inx%/FTO薄膜电极的光电转化效率高于N719/TiO2/FTO,并进一步讨论了光致界面电荷转移的机理. 展开更多
关键词 Tio2-Inx% o-In-Cln (n=1 2)物种 表面敏化 n719 Tio2-Inx% FTo 光电转换效率
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Effects of N doping on photoelectric properties of along different directions of ZnO bulk and nanotube
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作者 郑红梅 房晓勇 +4 位作者 蔡丽霞 尹爱查 金海波 于晓霞 曹茂盛 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第12期339-345,共7页
The electronic structures and optical properties of N-doped Zn O bulks and nanotubes are investigated using the firstprinciples density functional method. The calculated results show that the main optical parameters o... The electronic structures and optical properties of N-doped Zn O bulks and nanotubes are investigated using the firstprinciples density functional method. The calculated results show that the main optical parameters of Zn O bulks are isotropic(especially in the high frequency region), while Zn O nanotubes exhibit anisotropic optical properties. N doping results show that Zn O bulks and nanotubes present more obvious anisotropies in the low-frequency region. Thereinto, the optical parameters of N-doped Zn O bulks along the [100] direction are greater than those along the [001] direction, while for N-doped nanotubes, the variable quantities of optical parameters along the [100] direction are less than those along the[001] direction. In addition, refractive indexes, electrical conductivities, dielectric constants, and absorption coefficients of Zn O bulks and nanotubes each contain an obvious spectral band in the deep ultraviolet(UV)(100 nm~ 300 nm). For each of N-doped Zn O bulks and nanotubes, a spectral peak appears in the UV and visible light region, showing that N doping can broaden the application scope of the optical properties of Zn O. 展开更多
关键词 Zn o nTs n-doped Zn o electronic structure optical properties first-principles theory
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Stereoselective Addition of N-Alkylhydroxylamines to α,β-Unsaturated Nitro Compounds
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作者 Ai Jun LI Ji Cheng CHU +2 位作者 Hong Sheng GUO Xue Qin ZHOU Dong Zhi LIU 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第7期859-862,共4页
N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted additio... N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted addition mechanism was provided to explain the difference. 展开更多
关键词 n-Alkylhydroxylamines o-alkylhydroxylamines concerted addition mechanism α β-unsaturated nitro compounds stereoselectivity.
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A new triterpene saponin from Panax japonicus C.A.Meyer var major(Burk.) C.Y.Wu et K.M.Feng 被引量:4
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作者 Hong Zhao Lin Shi +3 位作者 Jia Qing Cao Wei Li Xia Wen Yu Qing Zhao 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第10期1216-1218,共3页
One new Iriterpene saponin was isolated from Panaxjaponicus C. A. Meyer var major (Burk.) C. Y. Wu et K. M. Feng, and established as oleanolic acid 3-O-[β-D-glucopyranosyl-(1 →2)-β-D-glucuronopyranosyl-6'-O-n-... One new Iriterpene saponin was isolated from Panaxjaponicus C. A. Meyer var major (Burk.) C. Y. Wu et K. M. Feng, and established as oleanolic acid 3-O-[β-D-glucopyranosyl-(1 →2)-β-D-glucuronopyranosyl-6'-O-n-butyl ester] which showed mod- erate antitumor activities against the A2780 cells and OVCAR-3 cells. Its structure was established by means of spectral data, particularly NMR, including HSQC and HMBC techniques. 展开更多
关键词 oleanolic acid 3-o-[β-D-glucopyranosyl-(1 2)-β-D-glucuronopyranosyl-6'-o-n-butyl ester] Antitumor Panax japonicus C. A.Meyer vat major (Burk) C Y wu et K. M Feng Triterpene saponin
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RESEARCH ON CONFORMATION OF CAPROLACTAM AND ITS ALKYL DERIVATIVES
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作者 蒋尚信 《Journal of China Textile University(English Edition)》 EI CAS 1995年第2期32-38,共7页
Caprolactam is treated with dimethyl sulfate in benzene medium under conditions of various molar ratios to yield two different methylatcd products. The homogeneous reaction of caprolactam with dimethyl sulfate without... Caprolactam is treated with dimethyl sulfate in benzene medium under conditions of various molar ratios to yield two different methylatcd products. The homogeneous reaction of caprolactam with dimethyl sulfate without any medium can only givc one methylated derivative. In a similar condition to that mentioned above, the reaction of caprolactam with diethylsulfate forms also one product, O-ethyl caprolactim. In this articlc NMR spectrum is applied to further identify the molecular structures of two methylated derivatives held by predecessors, and, applied the chemical shift reagent to induce the NMR and combined the field scanning and decoupling method to confirm the classification of signals, as a consequence the preferred conformation of caprolactam and its alkyl derivatives are proposed. 展开更多
关键词 ALKYLATIon CAPRoLACTAM o-methyl caprolactim n-methyl CAPRoLACTAM o-ethyl caprolactim chemical shift REAGEnT nMR spectrum.
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Adsorption of Pharmaceutical Contaminants from Aqueous Solutions Using N,O-Carboxymethyl Chitosan/Polyethylene Oxide (PEO) Electrospun Nanofibers
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作者 Amna Hassan Issa Khierallah Ilse Ileana Cardenas Bates +1 位作者 Bruno Chabot André Lajeunesse 《Journal of Materials Science and Chemical Engineering》 2021年第11期15-38,共24页
Residues of pharmaceutical and direct metabolites discharged into the aquatic environment have become a challenge for wastewater treatment facilities due to their increase in concentration and their different physicoc... Residues of pharmaceutical and direct metabolites discharged into the aquatic environment have become a challenge for wastewater treatment facilities due to their increase in concentration and their different physicochemical properties. These emerging contaminants are daily detected in surface water and wastewater discharged by municipalities. To remediate the contaminated water, various methods are currently used including primary, secondary, and tertiary advanced treatments. However, some economic and environmental limitations have forced the scientific community to develop alternative disinfection processes to purify wastewater. As such, the adsorption strategy represents a “green” low-cost and effective solution to remove pollutants from water. In this study, a nanomaterial made of N,O-carboxymethyl chitosan (N,O-CMCS) was prepared using chitosan (CS) and monochloroacetic acid under various conditions. N,O-CMCS electrospun was synthetized with the copolymer polyethylene oxide (PEO) to create nanofiber membranes showing a better specificity toward diversified contaminants depending on the pH of medium. The developed adsorbent was used to remove fluoxetine (FLX) from aqueous solutions. The new nanomaterial was characterised using FTIR, NMR, and SEM techniques. Sorption batch tests were carried out using high-performance liquid chromatography and ultraviolet diode array detector (HPLC-UV DAD) under controlled pH experimental conditions to determine the contaminant removal capacity of the nanomaterial. The promising adsorption results obtained with N,O-CMCS/PEO nanofibers are among the best ones obtained so far in comparison to other commercial and synthetized adsorbents tested for FLX’s adsorption. Kinetic experiments were also performed to investigate effects of contact times on the FLX adsorption. Experimental results were fitted to both common kinetic models pseudo-first and second order. The latter kinetic model described the best the sorption on surface. It revealed a possible chemisorption mechanism with electrostatic bounding for N,O-CMCS/PEO nanofibers. 展开更多
关键词 n o-Carboxymethyl Chitosan Electrospinning nanofibers ADSoRPTIon Pharmaceuticals
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A Kinetic Evidence for the Nitroxyl Radicals Recycling Mechanism in the Photostabilizing Process of HALS 被引量:3
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作者 XiaoXuanLIU XingHongZHANG +3 位作者 GuangGuoWU JianWenYANG ZhaoHuaZENG YongLieCHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第10期1085-1088,共4页
The photoinduced bulk polymerization of a reactive-hindered amine light stabilizers (r-HALS), 4-acryloyl-2, 2, 6,6-tetramethylpiperidinyl (ATMP), was performed at 80 C by using a DPC technique. An unique periodic expo... The photoinduced bulk polymerization of a reactive-hindered amine light stabilizers (r-HALS), 4-acryloyl-2, 2, 6,6-tetramethylpiperidinyl (ATMP), was performed at 80 C by using a DPC technique. An unique periodic exponential attenuation-type oscillating curve was found when the polymerization was carried out in air, but this phenomenon was not found in nitrogen. It is supposed that this unique kinetic performance may be attributed to nitroxyl radicals that are produced in situ from the oxidation of ATMP. ATMP polymer with narrow polydispersity (d = 1.03) can be obtained by photoinduced solution polymerization of ATMP. The signal detected in ESR may be assigned to the nitroxyl radicals in the matrix of ATMP polymer. Since this kind of recycling of nitroxyl radicals is well documented for the photostabilizing mechanism of HALS, the present results may serve as a kinetic evidence for this mechanism. 展开更多
关键词 Photopolymerization kinetics reactive-HALS (r-HALS) periodic exponential attenuation-type oscillating cycle photostabilizing mechanism nitroxyl radicals (>n-o).
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OPTICAL EFFECTS AND MICROSTRUCTURE OF BURIED INSULATOR LAYER FORMED BY O^+ AND N^+ CO-IMPLANTATION
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作者 俞跃辉 林成鲁 +2 位作者 朱文化 邹世昌 卢江 《Journal of Electronics(China)》 1992年第1期88-97,共10页
The microstructure and optical properties of a buried layer formed by O<sup>+</sup>(200keV,1.8×10<sup>18</sup>/cm<sup>2</sup>)and N<sup>+</sup>(180 keV,4×10<... The microstructure and optical properties of a buried layer formed by O<sup>+</sup>(200keV,1.8×10<sup>18</sup>/cm<sup>2</sup>)and N<sup>+</sup>(180 keV,4×10<sup>17</sup>/cm<sup>2</sup>)co-implantation and annealed at 1200℃for 2 h have been investigated by Auger electron,IR absorption and reflection spectroscopicmeasurements.The results show that the buried layer consists of silicon dioxide and SiO<sub>x</sub>(x【 2)and the nitrogen segregates to the wings of the buried layer where it forms an oxynitride.Bydetail theoretical analysis and computer simulation of the IR reflection interference spectrum,therefractive index profiles of the buried layer were obtained. 展开更多
关键词 optical effects MICRoSTRUCTURE BURIED insulator layer o^+ and n^+ co-implantation
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ent-Kaurene Diterpenoids from Isodon adenanthus
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作者 项伟 韩全斌 +2 位作者 黎胜红 纳智 孙汉董 《Acta Botanica Sinica》 CSCD 2003年第11期1383-1386,共4页
Three new ent-kaurene diterpenoids, adenanthins N, 0 and P (1-3), and four known diterpenoids, leucophyllin E (4), glabcensin C (5), adenanthin A (6), leucophyllin B (7), together with a highly unsaturated fatty acid,... Three new ent-kaurene diterpenoids, adenanthins N, 0 and P (1-3), and four known diterpenoids, leucophyllin E (4), glabcensin C (5), adenanthin A (6), leucophyllin B (7), together with a highly unsaturated fatty acid, 9,16-dioxo-10,1 2,14-octadeca-trienoic acid (8), were isolated from Isodon adenanthus (Diels) Kudo. The structure of compound 4 was revised accordingly. Compound I showed significant cytotoxic activity against K562 cells with IC50 = 0.45 mug/mL. 展开更多
关键词 Isodon adenanthus LABIATAE ent-kaurenoids adenanthins n o and P
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Extracellular O-linked β-N-acetylglucosamine: Its biology and relationship to human disease 被引量:2
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作者 Mitsutaka Ogawa Koichi Furukawa Tetsuya Okajima 《World Journal of Biological Chemistry》 CAS 2014年第2期224-230,共7页
The O-linked β-N-acetylglucosamine(O-GlcNAc)ylation of cytoplasmic and nuclear proteins regulates basic cellular functions and is involved in the etiology of neurodegeneration and diabetes. Intracellular O-GlcNAcylat... The O-linked β-N-acetylglucosamine(O-GlcNAc)ylation of cytoplasmic and nuclear proteins regulates basic cellular functions and is involved in the etiology of neurodegeneration and diabetes. Intracellular O-GlcNAcylation is catalyzed by a single O-GlcNAc transferase, O-GlcNAc transferase(OGT). Recently, an atypical O-GlcNAc transferase, extracellular O-linked β-N-acetylglucosamine(EOGT), which is responsible for the modification of extracellular O-GlcNAc, was identified. Although both OGT and EOGT are regulated through the common hexosamine biosynthesis pathway, EOGT localizes to the lumen of the endoplasmic reticulum and transfers GlcNAc to epidermal growth factor-like domains in an OGT-independent manner. In Drosophila, loss of Eogt gives phenotypes similar to those caused by defects in the apical extracellular matrix. Dumpy, a membrane-anchored apical extracellular matrix protein, was identified as a major O-GlcNAcylated protein, and EOGT mediates Dumpy-dependent cell adhesion. In mammals, extracellular O-GlcNAc was detected on extracellular proteins including heparan sulfate proteoglycan 2, Nell1, laminin subunit alpha-5, Pamr1, and transmembrane proteins, including Notch receptors. Although the physiological function of O-GlcNAc in mammals has not yet been elucidated, exome sequencing identified homozygous EOGT mutations in patients with Adams-Oliver syndrome, a rare congenital disorder characterized by aplasia cutis congenita and terminal transverse limb defects. This review summarizes the current knowledge of extracellular O-GlcNAc and its implications in the pathological processes in Adams-Oliver syndrome. 展开更多
关键词 Extracellular o-linked β -n-acetylglucosamine noTCH Adams-oliver syndrome
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基于同位素特征的华北平原菜地N_2O排放监测中取样时间的探讨 被引量:2
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作者 房福力 李玉中 《植物营养与肥料学报》 CAS CSCD 北大核心 2016年第4期978-987,共10页
【目的】为了长期监测土壤释放N_2O的通量和同位素变化规律,了解产生N_2O的微生物过程,提高对N_2O排放量和排放系数估计的准确性,需要对N_2O的日变化规律做深入研究,以便获得具有代表性的取样时间点及密闭时间。【方法】采用田间原位试... 【目的】为了长期监测土壤释放N_2O的通量和同位素变化规律,了解产生N_2O的微生物过程,提高对N_2O排放量和排放系数估计的准确性,需要对N_2O的日变化规律做深入研究,以便获得具有代表性的取样时间点及密闭时间。【方法】采用田间原位试验对华北平原的莴苣菜地进行了N_2O排放监测,选取N_2O排放高峰期即施肥灌溉后5 6 d为监测时间段,采用静态气体箱收集土壤释放的N_2O气体,结合气相色谱和质谱技术测定N_2O的含量及其同位素值(δ^(15)N-N_2O,δ^(18)O-N_2O和SP)。试验设2种取样间隔,即2 h和10 min,分别对N_2O日变化规律和密闭时间进行研究。【结果】1)在莴苣菜地N_2O排放高峰期内,N_2O通量日变化范围为34.65 131.45μg/(m^2·h),最大和最小的通量分别发生在13:00和次日5:00,9:00的N_2O通量为83.66μg/(m^2·h),与日通量平均值82.81μg/(m^2·h)相接近。N_2O通量产生日变化的原因与土壤温度有关,相关分析表明,N_2O通量与地下5 cm处土壤温度呈显著正相关(R2=0.82,P<0.01),而与土壤充水孔隙度(WFPS)无显著相关性。2)24 h内,δ^(15)Nbulk-N_2O和δ^(18)O-N_2O随着时间呈现先降低后增加的变化趋势,变化范围分别为-31.22‰-11.09‰和-7.45‰-0.68‰;SP值随时间呈现先增加后降低的变化趋势,变化范围为16.13‰26.41‰。N_2O各个同位素值随时间的变化表明产生N_2O的微生物过程随之变化,但SP值在9:00 17:00较稳定,变化范围为23.26‰26.21‰,极显著高于其他时刻(P<0.01),表明硝化作用在这一时间段内对N_2O的产生起主导作用。3)扣箱40min后,N_2O含量、δ15N-N_2O和SP值都达到稳定状态,因此选取40 min作为单次观测N_2O含量和同位素变化的密闭时间。4)24 h内N_2O通量加权SP值为22.54‰。根据前人总结的规律,本研究中N_2O主要由细菌硝化作用产生,且估计60.92%的N_2O来自于细菌硝化作用,39.08%的N_2O来自于反硝化作用。【结论】华北平原莴苣菜地的N_2O通量和同位素值具有较大的日变化,综合N_2O通量和同位素值,建议选取9:00作为观测莴苣菜地N_2O排放通量和同位素特征值变化规律的时刻,建议静态气体箱密闭时间为40 min。 展开更多
关键词 n_2o通量 δ-(15)n-n_2o δ-(18)o-n_2o SP 日变化
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