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水溶—释放作用对气藏形成的影响——以克拉2气田为例 被引量:18
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作者 王青 张枝焕 +5 位作者 钟宁宁 张水昌 李艳霞 程秀坤 刘洪军 文坚 《天然气工业》 EI CAS CSCD 北大核心 2004年第6期18-21,共4页
以克拉 2气田为例 ,讨论了天然气在地层水中溶解—释放作用对气藏形成的影响 ,估算了因地层抬升所导致的水溶气释放为游离气的量 ,分析了影响水溶气与气藏中游离气组分分馏的主要因素。研究表明 ,天然气在地层水中的溶解—释放作用对克... 以克拉 2气田为例 ,讨论了天然气在地层水中溶解—释放作用对气藏形成的影响 ,估算了因地层抬升所导致的水溶气释放为游离气的量 ,分析了影响水溶气与气藏中游离气组分分馏的主要因素。研究表明 ,天然气在地层水中的溶解—释放作用对克拉 2气田天然气组分分馏起重要的作用 ,主要表现为 :①在地层沉降和抬升过程中 ,由于地层温度、压力的变化 ,地层水选择性溶解和释放天然气组分 ;②在大规模水平挤压过程中 ,C2 + 烃类气体随着边底水的迁移而流失 ;③地层异常高压导致大量C2+ 烃类溶解于地层水中 ,致使气藏中甲烷相对富集。此外 ,水溶气释放对克拉 2气田异常高压的形成也有一定的贡献作用。文章还通过天然气在水中溶解—释放模拟试验 ,分析了甲烷气体在地层水中因压力变化而释放的过程中碳同位素分馏状况。总结了克拉 2气藏水溶气成藏过程及其成藏模式。 展开更多
关键词 气藏 水溶-释放作用 克拉2气田 天然气 异常压力 油气运移
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煤层气甲烷碳同位素的特征及分馏效应 被引量:14
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作者 李五忠 雍洪 李贵中 《天然气工业》 EI CAS CSCD 北大核心 2010年第11期14-16,共3页
煤层气甲烷碳同位素值记录了煤层气成藏和开发过程中的一些有用信息。为此,测试了我国5个典型盆地、不同煤阶的72个煤层气样品的δ13C1,从热演化过程、生物降解作用、解吸吸附过程、水的溶蚀作用4个方面分析了煤层气甲烷同位素的分馏效... 煤层气甲烷碳同位素值记录了煤层气成藏和开发过程中的一些有用信息。为此,测试了我国5个典型盆地、不同煤阶的72个煤层气样品的δ13C1,从热演化过程、生物降解作用、解吸吸附过程、水的溶蚀作用4个方面分析了煤层气甲烷同位素的分馏效应。结论认为:从煤层气的成藏到开发的整个过程,其甲烷同位素的分馏效应是普遍存在的;根据这一特点,可以帮助判断煤层气的气源与成藏过程、判断煤层气井的开发状态及采收率、判断煤层水的活跃程度,从而更加精确地评价煤层气富集的有利目标区。 展开更多
关键词 煤层气 甲烷同位素 分馏效应 热演化 生物降解 解吸 吸附 水溶作用
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中国中西部砂岩天然气大规模聚集机制与成藏效应 被引量:10
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作者 李伟 王雪柯 +3 位作者 张本健 陈竹新 裴森奇 于志超 《石油勘探与开发》 SCIE EI CAS CSCD 北大核心 2020年第4期668-678,共11页
中国中西部大型含油气盆地中天然气大规模富集区具有多种特殊的聚集机制与不同的成藏效应。以天然气成藏地质理论与方法为基础,开展了典型含油气盆地区域地质与构造背景、地层埋藏演化、气藏基本特征、流体地质与地球化学等方面的研究... 中国中西部大型含油气盆地中天然气大规模富集区具有多种特殊的聚集机制与不同的成藏效应。以天然气成藏地质理论与方法为基础,开展了典型含油气盆地区域地质与构造背景、地层埋藏演化、气藏基本特征、流体地质与地球化学等方面的研究。结果认为,喜马拉雅期以来隆升剥蚀所产生的构造抽吸、泥岩吸水、水溶气脱溶、流体封存等地质作用都能形成大规模的天然气聚集,并能形成不同的天然气成藏地质效应。如:大面积的构造抽吸作用与流体封存作用有利于区域性超高压流体的赋存及大规模超高压气田的形成;低砂地比地层中产生的泥岩吸水作用有利于区域性低压、无水气藏等大气区的发育;大面积厚层砂岩中水溶气的脱溶作用不仅能形成大规模的天然气聚集,而且地层水侧向运移产生的水溶气脱溶,会产生区域性有规律的天然气同位素分馏效应,即天然气水溶气运移距离越远,所聚集形成的天然气甲烷碳同位素组成越重。 展开更多
关键词 中国中西部盆地 天然气大规模聚集机制 构造抽吸作用 泥岩吸水作用 水溶气脱溶作用 流体封存作用 天然气成藏
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Anti-tumor Effect and Protective Effect on Chemotherapeutic Damage of Water Soluble Extracts from Hedyotis diffusa 被引量:25
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作者 李瑞 赵浩如 林以宁 《Journal of Chinese Pharmaceutical Sciences》 CAS 2002年第2期54-58,共5页
Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic mater... Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic material, promoting blood circulation and removing blood stasis'.It is a well known Chinese folk-medicine used for the treatment of appendicitis, sore throat, mumps,acne, sebo-rheic dermatitis and various kinds of tumors, such as tumors of digestive tract,carcinoma of liver. It was reported that the MeOH extract of H. diffusa demonstrated a significantantitumor activity and ursolic acid succeeded in being isolated from the MeOH extract as an activecomponent . Shan BN, et al suggested that the direct aqueous extract of H. diffusa hadimmuno-modulating activity and antitumor activity in vitro through stimulating the immune system tokill or engulf tumor cells. But regarding anti-tumor activity in vivo of water soluble extracts fromH. diffusa, no detail was reported. Therefore, we prepared water soluble extracts (H_1 and H_2)from H. diffusa and evaluated their anti-tumor property in vivo experiments as well as protectiveeffect on chemo-therapeutic damage. 展开更多
关键词 hedyotis diffusa water soluble extracts ANTI-TUMOR CHEMOTHERAPY
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A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in aqueous solutions and its applications in binary and ternary aqueous solutions 被引量:1
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作者 杨学民 赵伟洁 +2 位作者 柴国明 郭汉杰 张强 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期626-641,共16页
A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexi... A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexistence theory and verified in four kinds of binary aqueous solutions and two kinds of ternary aqueous solutions. The calculated mass action concentrations of structural units or ion couples in four binary aqueous solutions and two ternary solutions at 298.15 K have good agreement with the reported activity data from literatures after shifting the standard state and concentration unit. Therefore, the calculated mass action concentrations of structural units or ion couples from the developed universal thermodynamic model for ternary and binary aqueous solutions can be applied to predict reaction ability of components in ternary and binary strong electrolyte aqueous solutions. It is also proved that the assumptions applied in the developed thermodynamic model are correct and reasonable, i.e., strong electrolyte aqueous solution is composed of cations and anions as simple ions, H2O as simple molecule and other hydrous salt compounds as complex molecules. The calculated mass action concentrations of structural units or ion couples in ternary and binary strong electrolyte aqueous solutions strictly follow the mass action law. 展开更多
关键词 universal thermodynamic model mass action concentration activity ternary aqueous solution binary aqueous solution ion and molecule coexistence theory structural units ion couples components
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Treatment of Dimethoate Aqueous Solution by Using Ultrasonic Airlift Loop Reactor 被引量:8
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作者 刘越男 金栋 +1 位作者 吕效平 韩萍芳 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第3期361-364,共4页
Ultrasonic airlift loop reactor (UALR) shows potential and wide application for wastewater treatment. In this paper the performance and efficiency of UALR in dimethoate degradation were presented. The effects of O3 ... Ultrasonic airlift loop reactor (UALR) shows potential and wide application for wastewater treatment. In this paper the performance and efficiency of UALR in dimethoate degradation were presented. The effects of O3 flow rate, ultrasonic intensity and initial concentration of dimethoate on degradation rate were investigated. UALR imposed a synergistic effect combining sonochemical merit with high O3 transfer rate. The results showed that UALR not only increased degradation rate, but also was better than the simole sum of degradation by O3 and ultrasound separately. Under the operation conditions of O3 flow of 0.34 m^3·h^-1, ultrasonic intensity 3.71 W.cm^-2, and initial concentration of dimethoate at 20 mg·L^- 1, the degradation rate of dimethoate increased to 80%. UALR seems an advisable choice for treating organic wastewater and this process may have wide application prospect in industry. 展开更多
关键词 DIMETHOATE ULTRASOUND airlift loop reactor O3 synergistic effect DEGRADATION
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Salt-Water Dynamics in Soils: II. Effect of Precipitation on Salt-Water Dynamics 被引量:6
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作者 YOUWEN-RUI MENGFAN-HUA 《Pedosphere》 SCIE CAS CSCD 1992年第4期289-306,共18页
Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity s... Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensiometers. The results show that in the profile of whole silty loam soil, the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water; and in the profile with an intercalated bed of clay or with a thick upper layer of clay, the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil. In case of soil water being supplemented by precipitation, the evaporation of groundwater in the soil columns reduced, resulting in a great decline of salt accumulation from soil profile to surface soil. The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer. The direct infiltration depth of precipitation was less than 1 m in general, but water pressure transfer could go up to groundwater surface directly. 展开更多
关键词 groundwater evaporation precipitation infiltration salt-water dynamics salt-leaching surface runoff
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Volumetric and Viscometric Studies of 4-Aminobutyric Acid in Aqueous Solutions of Salbutamol Sulphate at 308.15, 313.15 and 318.15K 被引量:4
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作者 K. Rajagopal S.S. Jayabalakrishnan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第5期796-804,共9页
Density (ρ) and viscosity (η) measurements were carried out for 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·L-1 aqueous salbutamol sulphate at T=308.15,313.15 and 318.15K.The measured values of dens... Density (ρ) and viscosity (η) measurements were carried out for 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·L-1 aqueous salbutamol sulphate at T=308.15,313.15 and 318.15K.The measured values of density and viscosity were used to estimate some important parameters such as apparent molar volume Vφ,limiting apparent molar volume Vφ0,transfer volume △Vφ0,hydration number Hn,second derivative of infinite dilution of partial molar volume with temperature 2Vφ0/T2,viscosity B-coefficients,variation of B with temperature dB/dT,free energy of activation per mole of solvent △μ10* and solute △μ20*,activation entropy △S20* and activation enthalpy △H20* of the amino acids.These parameters have been interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution. 展开更多
关键词 DENSITY standard partial molar volume hydration ntnZnber relative viscosity B-COEFFICIENT activation parameters
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Controls of Soluble Al in Experimental Acid Sulfate Conditions and Acid Sulfate Soils 被引量:1
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作者 LINCHUXIA M.D.MELVILLE 《Pedosphere》 SCIE CAS CSCD 1997年第2期97-102,共6页
The controls of soluble Al concentration were examined in three situations of acid sulfate conditions: 1)experimental acid sulfate conditions by addition of varying amounts of Al(OH)3 (gibbsite) into a sequenceof H2SO... The controls of soluble Al concentration were examined in three situations of acid sulfate conditions: 1)experimental acid sulfate conditions by addition of varying amounts of Al(OH)3 (gibbsite) into a sequenceof H2SO4 solutions; 2) experimental acid sulfate conditions by addition of the same sequence of H2SO4solutions into two non-acid sulfate soil samples with known amounts of acid oxalate extractable Al; and3) actual acid sulfate soil conditions. The experiment using gibbsite as an Al-bearing mineral showed thatincrease in the concentration of H2SO4 solution increased the soluble Al concentration, accompanied bya decrease in the solution pH. Increasing amount of gibbsite added to the H2SO4 solutions also increasedsoluble Al concentration, but resulted in an increase in solution pH. Within the H2SO4 concentration rangeof 0.0005~0.5 mol L-1 and the Al(OH)3 range of 0.01~0.5g (in 25 mL of H2SO4 solutions), the input ofH2SO4 had the major control on soluble Al concentration and pH. The availability of Al(OH)3, however, wasresponsible for the spread of the various sample points, with a tendency that the samples containing moregibbsite had a higher soluble Al concentration than those containing less gibbsite at equivalent pH levels.The experimental results from treatment of soil samples with H2SO4 solutions and the analytical results ofacid sulfate soils also showed the similar trend. 展开更多
关键词 acid sulfate conditions acid sulfate soils GIBBSITE soluble Al
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Adsorption,Oxidation and Complexation of Water-So-Inble Organic Snbstances in Soils 被引量:3
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作者 DING CHANG-PUInstitute of Sozl Sczence, Academza Sznica, P. O. Boz 82i, Nalzjzng 210008 (China) ) 《Pedosphere》 SCIE CAS CSCD 1995年第2期171-178,共8页
A greater part of water-solnble organic substances, accounting for 6070To of the total, could be adsorbedby soils, which included strongly and weekly reducing substances, positively and negatively charged substancesan... A greater part of water-solnble organic substances, accounting for 6070To of the total, could be adsorbedby soils, which included strongly and weekly reducing substances, positively and negatively charged substancesand substances containing amido. There existed a tendency of decrease in adsorption of the negativelycharged organic substances by the soil from South China to North China, with expression as Coulombianadsorption. A simultaneous reduction of iron and manganese appeared with clear voltammetric behavioursupon oxidation of water-soluble organic substances. Complexation of organic ligands with ferrons iron andmanganous manganese was proved by differential pulse voltammetric method, with disappearance of oxidationpeaks of ferrous iron and manganous manganese at 0.00 V and 0.35 V and occurrence of Fe`+-complex andMn ̄2+ -complex at 0.75 V and 1.2 V respectively, whose peak potentials shifted backward. 展开更多
关键词 ADSORPTION COMPLEXATION OXIDATION voltammetric behaviour water-solube organic substances
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Adsorption Behavior of a Water-soluble Porphyrin at the Glass-water Interface as Studied by Synchronous Total Internal Reflection Fluorescence Spectroscopy
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作者 MinNaYAO YaoQunLI 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第1期109-111,共3页
Total internal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) at the glass-water... Total internal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS4-) and diprotonated (H2TPPS2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface. 展开更多
关键词 Total internal reflection fluorescence synchronous fluorescence water- soluble porphyrin pH dependence glass-water interface.
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Adsorption of phenol from water by ultrafine coal powders
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作者 刘转年 周安宁 +1 位作者 杨帆 金奇庭 《Journal of Coal Science & Engineering(China)》 2007年第1期99-103,共5页
Seven Shenfu coal powders different in particle size obtained by sieving and ball milling were used to probe their adsorption properties to phenol from water. The results show that the kinetics of phenol on coal powde... Seven Shenfu coal powders different in particle size obtained by sieving and ball milling were used to probe their adsorption properties to phenol from water. The results show that the kinetics of phenol on coal powders follow the second-order adsorption kinetic model well. Adsorption processes are governed by film diffusion and the kinetic parameters and the effective diffusion coefficients were calculated through plotting. Adsorption capacities to phenol increase exponentially with decreasing of diameter of coal powders. The phenol adsorption equilibrium for coal powder with d50 of 9.30 μm can be described in terms of Freundlich isotherm, while for ultrafine coal powders with d50 of 4.28 and 4.82 μm fit Langmuir isotherm well. 展开更多
关键词 ultrafine coal powders PHENOL ADSORPTION
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Molecular Dynamics Simulation Study of CIF in Water: Halogen Bonding Interaction in Liquid
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作者 Yu-feng Ye Cen-feng Fu Shan-xi Tian 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第1期25-28,I0001,共5页
Does the halogen bonding interaction co-exist in liquid when it competes with the hydrogen bonding interaction? The classical molecular dynamics simulations for the solvation properties of CLF molecule in water are p... Does the halogen bonding interaction co-exist in liquid when it competes with the hydrogen bonding interaction? The classical molecular dynamics simulations for the solvation properties of CLF molecule in water are performed with the Lennard-Jones plus Coulomb electrostatic potential parameters that are optimized with ab initio interaction energy calculations for the pre-reactive H2O-CLF complex. We find that the halogen bonding interactions occur between O and CL atoms and have the comparable strength and population with respect to the hydrogen bonding interactions of C1...H. 展开更多
关键词 Halogen bonding interaction Molecular dynamics simulation C1F molecule Hydrogen bonding interaction Aqueous solution
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Effect Mechanism of Structure-Changed Water on Heat Stability of Lysozyme 被引量:1
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作者 赵林 谭欣 《Transactions of Tianjin University》 EI CAS 2003年第3期177-179,共3页
Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The ... Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The results obtained by differential scanning calorimetry (DSC) showed that the thermal denaturation temperature of lysozyme had been elevated 8.47 K through hydration of lysozyme with processed water whose structure had been changed so it was called "structured water" compared to ordinary water. The reason is that structured water changed the dipole moment of water molecules and easily formed cyclic water hexamer or cage-like water hexamer, so that the interacting force of maintaining three-dimensional conformation of lysozyme could be reinforced. 展开更多
关键词 LYSOZYME heat stability structured water water molecule clusters
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Abatement of Arsenite from Water by Glow Discharge Electrolysis
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作者 Patil Dilip Bhaskar Chafle Dilip Marotrao 《Journal of Environmental Science and Engineering(A)》 2012年第7期880-885,共6页
Glow discharge electrolysis provides an alternative method for the removal of arsenite from water. Glow discharge electrolysis of aqueous solution containing arsenite is studied under altemating current altemating cur... Glow discharge electrolysis provides an alternative method for the removal of arsenite from water. Glow discharge electrolysis of aqueous solution containing arsenite is studied under altemating current altemating current (50 Hz) discharge. It is found that arsenite [As(III)] get converted to arsenate [As(V)]. The yield is studied with various parameters such as discharge current, duration of discharge and pH (2-10). The results are interpreted on the basis of interaction of the OH and eaq (produced consequent to the interaction of H2O+ and e with water at the surface of the solution) with arsenite [As(III)] through the intermediate oxidation state, namely [As(IV)]. 展开更多
关键词 Glow discharge electrolysis arsenite removal interaction of OH and e surface interaction.
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Chemical Interaction UO2Cl2 with α-and β-Amino Acids in Aqueous and Organic Solution
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作者 Aibassov Erkin Zhakenovich Kenzhaliev Bagdaulet Kenzhalievich2 +4 位作者 Tussupbaev Nessipbay Kuandykovich Berkinbaeva Ainura Chukmanova Marzhan Iskhakova Renata Bulenbayev Maxat Zhumabaevich 《Journal of Chemistry and Chemical Engineering》 2014年第7期751-756,共6页
This paper presents the results of the search of biologically active uranium compounds such as amino acids. We first received and examined X-ray and IR (infrared radiation) spectroscopy of uranium complexes with α-... This paper presents the results of the search of biologically active uranium compounds such as amino acids. We first received and examined X-ray and IR (infrared radiation) spectroscopy of uranium complexes with α- and β-amino acids in aqueous and organic solution. We proposed a method for direct synthesis of complex organic compounds of uranium chloride UO2Cl2 with α- andβ-amino acids for the synthesis of drugs for the treatment of cancer. 展开更多
关键词 X-ray and IR spectroscopy bioorganic chemistry of uranium synthesis of complex organic compounds of UO2Cl2 with α- and β-amino acids.
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Molecular Dynamics Simulation of Effect of Salt on the Compromise of Hydrophilic and Hydrophobic Interactions in Sodium Dodecyl Sulfate Micelle Solutions 被引量:1
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作者 高健 任瑛 葛蔚 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第4期654-660,共7页
The presence of salt has a profound effect on the size,shape and structure of sodium dodecyl sulfate(SDS)micelles.There have been a great number of experiments on SDS micelles in the presence and absence of salt to st... The presence of salt has a profound effect on the size,shape and structure of sodium dodecyl sulfate(SDS)micelles.There have been a great number of experiments on SDS micelles in the presence and absence of salt to study this complex problem.Unfortunately,it is not clear yet how electrolyte ions influence the structure of micelles.By describing the compromise between dominant mechanisms,a simplified atomic model of SDS in presence of salt has been developed and the molecular dynamics(MD)simulations of two series of systems with different concentrations of salt and charges of ion have been performed.Polydispersity of micelle size is founded at relatively high concentration of SDS and low charge of cation.Although the counter-ion pairs with head groups are formed,the transition of micelle shape is not observed because the charge of cation is not enough to neutralize the polar of micelle surface. 展开更多
关键词 molecular dynamics simulation COMPROMISE sodium dodecyl sulfate SALT MICELLE
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Effects of elevated CO_2 on the photosynthesis and nitrate reductase activity of Pyropia haitanensis(Bangiales,Rhodophyta) grown at different nutrient levels 被引量:2
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作者 刘春香 邹定辉 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第2期419-429,共11页
Pyropia haitanensis, a commercially important species, was cultured at two CO2 concentrations (390× 10^-6 and 700× 10^-6 (parts per million)) and at low and high nutrient levels, to explore the effect of... Pyropia haitanensis, a commercially important species, was cultured at two CO2 concentrations (390× 10^-6 and 700× 10^-6 (parts per million)) and at low and high nutrient levels, to explore the effect of elevated CO2 on the species under nutrient enrichment. Results show that in CO2-enriched thalli, relative growth rate (RGR) was enhanced under nutrient enrichment. Elevated CO2 decreased phycobiliprotein (PB) contents, but increased the contents of soluble carbohydrates. Nutrient enrichment increased the contents of chlorophyll a (Chl a) and PB, while soluble carbohydrate content decreased. CO2 enrichment enhanced the relative maximum electronic transport rate and light saturation point. In nutrient-enriched thalli the activity of nitrate reductase (NRA) increased under elevated CO2. An instantaneous pH change in seawater (from 8.1 to 9.6) resulted in reduction of NRA, and the thalli grown under both elevated CO2 and nutrient enrichment exhibited less pronounced reduction than in algae grown at the ambient CO2. The thermal optima of NRA under elevated CO2 and/or nutrient enrichment shifted to a lower temperature (10-15 ℃) compared to that in ambient conditions (20℃). We propose that accelerated photosynthesis could result in growth increment. N assimilation remained high in acidified seawater and reflected increased temperature sensitivity in response to elevated CO_2 and eutrophication. 展开更多
关键词 Pyropia haitanensis PHOTOSYNTHESIS nitrate assimilation elevated CO2 EUTROPHICATION
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Effect of β-Cyclodextrin Upon the Sol-gel Transition of Methylcellulose Solutions in the Presence of Sodium Dodecyl Sulfate
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作者 Hua-yu Li Xiang Hao +3 位作者 Yong-jun Xie Hai-yang Yang He Liu Jian-hui Luo 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第2期242-248,I0004,共8页
The sol-gel transition temperature of methylcellulose (MC) solution in the presence of sodium dodecyl sulfate (SDS) as well as the mixtures of SDS and β-cyclodextrin (β-CD) was mea- sured, and the effect of th... The sol-gel transition temperature of methylcellulose (MC) solution in the presence of sodium dodecyl sulfate (SDS) as well as the mixtures of SDS and β-cyclodextrin (β-CD) was mea- sured, and the effect of the two competing interactions, the hydrophobic interaction between SDS and MC and the inclusion interaction between SDS and β-CD, upon the sol-gel transition of MC solution was studied. It has been found that the inclusion interaction between SDS and β-CD is much greater than the hydrophobic interaction between SDS and MC. As a result, in the coexistence of SDS and β-CD, the sol-gel transition temperature of MC solution keeps the same value, independent of the concentration of SDS in solution on con- dition that the concentration of SDS is less than β-CD. Our experimental results not only suggest that the effect of SDS upon the sol-gel transition of MC solution can be screened by β-CD completely but also indicate the inclusion ratio of SDS to β-CD can be determined quantitatively by using rheological measurement. The inclusion ratio of SDS to β-CD is 1:1, which is in good agreement with the inclusion ratio of SDS to β-CD in the presence of poly(vincyl pyrrolidone) determined by the viscosity measurement but is critically different from the inclusion ratio of SDS to β-CD in the presence of the oppositely charged polyelec-trolyte by using the rheological measurement, mainly due to the reason that the mechanism of the interaction between SDS and MC is critically different from the mechanism of the interaction between SDS and the oppositely charged polyelectrolyte. 展开更多
关键词 METHYLCELLULOSE Sodium dodecyl sulfate Β-CD Sol-gel transition Inclusion interaction
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Sorption of norfloxacin from aqueous solutions by activated carbon developed from Trapa natans husk 被引量:5
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作者 XIE HuiJun LIU WeiFeng +2 位作者 ZHANG Jian ZHANG ChengLu REN Liang 《Science China Chemistry》 SCIE EI CAS 2011年第5期835-843,共9页
The low-cost activated carbon was prepared from a renewable aquatic plant residue,Trapa natans husk,and tested for its ability to remove norfloxacin (NOR) from aqueous solutions. Physical and chemical properties of th... The low-cost activated carbon was prepared from a renewable aquatic plant residue,Trapa natans husk,and tested for its ability to remove norfloxacin (NOR) from aqueous solutions. Physical and chemical properties of the Trapa natans husk activated carbon (TAC) were characterized. TAC has a large surface area of 1274 m2/g and mesoporous structure. Carboxylic and hydroxyl groups contributed to the sorption of NOR onto TAC but they were not the most important factors in the sorption process. The rates of adsorption followed the pseudo-second-order kinetics and the overall rate of NOR uptake was controlled by both external mass transfer and intro particle diffusion during the entire adsorption period. The equilibrium data fitted well with the Freundlich and Tempkin models and the sorption was found to be a favorable process. The adsorption of NOR by TAC was strongly dependent on the solution pH. Electrostatic interaction and hydrophobic interaction were proposed to be the principal NOR sorption mechanism. 展开更多
关键词 NORFLOXACIN Trapa natans husk activated carbon adsorption kinetic and isotherms
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