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Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): Effect of OH/Al, Si/Al molar ratios and initial pH 被引量:7
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作者 Zhonglian Yang Baoyu Gao +2 位作者 Yan Wang Yaqin Zhao Qinyan Yue 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第11期1908-1916,共9页
An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly- aluminum-silicate-chloride (PASiC) in terms of the residual A1 fractions as a function of ... An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly- aluminum-silicate-chloride (PASiC) in terms of the residual A1 fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual A1 ratio of the composite PASiC coagulant. The main residual A1 sources were the A1 fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00-7.00, while the concentrations of various residual A1 species and the residual A1 ratio of PASiC were minimal at an initial pH range of 7.00-8.00. Under the conditions of OH/AI molar ratio = 2.00 and Si/A1 molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual A1 concentrations. The A1 fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended (filterable) AI fraction was the dominant species, and organic-bound or organo-A1 complex A1 was considered to be the major species of dissolved A1 in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric A1 species dominated the dissolved monomeric A1 fraction. 展开更多
关键词 coagulation performance OH/A1 and Si/AI molar ratio poly-aluminum-silicate-chloride (PAniC) resi0ual AI speclataon residual A1 ratio
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Influence of MgO/MgCl_2 Molar Ratio on Phase Stability of Magnesium Oxychloride Cement 被引量:8
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作者 巴恒静 关辉 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第3期476-481,共6页
Formation, solution and phase change of hydration products in MgO-MgCl2-H2O system was studied with thermodynamics method, and resistance to water immersion and phase change of magnesium oxychloride cement with differ... Formation, solution and phase change of hydration products in MgO-MgCl2-H2O system was studied with thermodynamics method, and resistance to water immersion and phase change of magnesium oxychloride cement with different MgO/MgCl2 molar ratio was experimented. The results show that pH value of immersion solution of cement paste has a remarkable influence on phase stability of hydration products. A higher pH value leads to a lower solubility and a better phase stability of hydration products. When the solution pH value is higher than 10.37, the precipitation of much Mg(OH)2 crystal induces a worse phase stability of hydration products. With the increasing MgO/MgCl2 molar ratio (lower than 6), the more amount of MgO in the hydration products enhances the alkalinity of solution and the phase stability is improved. However, when the MgO/MgCl2 molar ratio is higher than 6 and the excessive MgO exsits in the hydration products, the cement paste may be damaged by the excessive crystallization stress of a great deal of Mg(OH)2 formation. 展开更多
关键词 magnesium oxychloride cement molar ratio phase stability hydration reaction
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Optimization of Cr/Mo molar ratio in FeCoCrMoCBY alloys for high corrosion resistance 被引量:3
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作者 Cheng-jie WANG Qing-jun CHEN Huai-xiao XIA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第12期2663-2672,共10页
The corrosion behavior of bulk metallic glasses(BMGs)(Fe41Co7Cr15Mo14C15B6Y2)100-xCrx(x=0,4,8,12,molar fraction,%)was investigated in1mol/L HCl aqueous solution with electrochemical tests.The electrochemical measureme... The corrosion behavior of bulk metallic glasses(BMGs)(Fe41Co7Cr15Mo14C15B6Y2)100-xCrx(x=0,4,8,12,molar fraction,%)was investigated in1mol/L HCl aqueous solution with electrochemical tests.The electrochemical measurements demonstrate that the passive current density of Fe-based amorphous alloy is reduced by about one order of magnitude,and meanwhile,the stability of passive film can be guaranteed by the Cr/Mo molar ratio.The Mott–Schottky(M–S)curves show that the passive film is the densest when the molar ratio of Cr/Mo is between1.37and1.69.X-ray photoelectron spectroscopy(XPS)analysis was performed to clarify chemical states of elements in the passive films.The results show that the corrosion resistance of the alloy is related to the molar ratio of Cr/Mo.The stability of passive film is determined by the synergistic action of Cr and Mo elements.The main component of the passive film is Cr3+oxide.When the potential is greater than0.5V(vs SCE),Mo6+ions play an important role in keeping the stability of the passive film.The appropriate molar ratio of Cr/Mo can reduce the dissolution rate of the passive film. 展开更多
关键词 bulk metallic glasses corrosion resistance passive film electrochemical measurement Cr/Mo molar ratio
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Silica-alumina molar ratio and some factors effect on the synthesis of zeolites from fly ash 被引量:2
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作者 SUN Yue-zhi FU Ke-ming +1 位作者 ZHU Hong ZHU Tian-lin 《Journal of Coal Science & Engineering(China)》 2009年第4期430-433,共4页
In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, whi... In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, which is hydrothermally treated at about 104 ℃, and the liquid/solid ratio was controlled at 6:1. In order to control Si/Al molar ratio, SiO2 or Al2O3 powers were added to the fly ash. The results of XRD and SEM show that the alkali melted can activate fly ash and eliminate its quartz and mullite, along with the improvement of Si/Al molar ratio and alkalinity. In addition, zeolite Na-A changes into sodalite gradually, and nepheline is the synthesized intermediate product. Those results were discussed on the basis of a formation mechanism of zeolite from fly ash. 展开更多
关键词 fly ash ZEOLITE hydrothermal treatment Si/Al molar ratio
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Effects of temperature and initial molar ratio of Na_2O to Al_2O_3 on agglomeration of fine Al(OH)_3 seed in synthetic Bayer solution 被引量:1
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作者 张斌 陈启元 +1 位作者 李洁 尹周澜 《Journal of Central South University of Technology》 2008年第6期786-790,共5页
Fine Al(OH)3 crystals were aggregated from supersaturated aluminate solution in the batch reaction tanks. By means of laser particle size analyzer and scanning electron microscopy, the influences of temperature and ... Fine Al(OH)3 crystals were aggregated from supersaturated aluminate solution in the batch reaction tanks. By means of laser particle size analyzer and scanning electron microscopy, the influences of temperature and initial molar ratio of Na2O to Al2O3 (aK) on agglomeration of fine seed in Bayer process were investigated. The results show that agglomeration is almost finished in 8 h, and seeds with size less than 2 μm are easily aggregated together, and almost disappear in 8 h under the optimal process conditions. In the aluminate solution with the same moderate initial aK, when the reaction temperature reaches 75 ℃, the secondary nucleation does not occur, and the effect of agglomeration is better. And at the same reaction temperature, when the initial aK is 1.62, the initial supersaturation of aluminate solution is moderate, the binders on the surfaces of the seed are enough to maintain the agglomeration process, and the agglomeration degree is better. From SEM images, agglomeration mainly occurs in the fine particles, the combinations among the fine particles are loose and the new formed coarse crystal shapes are irregular. 展开更多
关键词 sodium aluminate Bayer process screen separation AGGLOMERATION initial molar ratio of Na2O to Al2O3
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Molar ratio induced crystal transformation from coordination complex to coordination polymers
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作者 Peng Meng Qian-Cheng Luo +7 位作者 Aidan Brock Xiaodong Wang Mahboobeh Shahbazi Aaron Micallef John McMurtrie Dongchen Qi Yan-Zhen Zheng Jingsan Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第4期539-543,共5页
Coordination complex of a copper cyanurate(Cu(Ⅱ)-CA) was transformed into coordination polymers upon the stimulus of extra Cu(Ⅱ) through “directed Ostwald ripening”. By increasing the molar ratio of Cu(Ⅱ) to CA, ... Coordination complex of a copper cyanurate(Cu(Ⅱ)-CA) was transformed into coordination polymers upon the stimulus of extra Cu(Ⅱ) through “directed Ostwald ripening”. By increasing the molar ratio of Cu(Ⅱ) to CA, we obtained two coordination polymers with selective coordination sites: Cu(Ⅱ)-κ N(HCA)κ NCu(Ⅱ) and Cu(Ⅱ)-κ N(HCA)κ O-Cu(Ⅱ), which display disparate magnetic interactions. 展开更多
关键词 molar ratio dependent crystal transformation Copper cyanurate Ostwald ripening Molecular magnetism One-dimensional chain
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Mechanistic investigation on the Hg^(0)elimination ability of MnO_(x)-CeO_(x)nanorod adsorbents:effects of Mn/Ce molar ratio
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作者 Shujie Gao Xiaoxiang Wang +3 位作者 Yaolin Wang Kai Zhu Changxing Hu Dong Ye 《Waste Disposal and Sustainable Energy》 EI CSCD 2024年第2期185-196,共12页
Mercury pollution is created by coal combustion processes in multi-component systems.Adsorbent injection was identified as a potential strategy for capturing Hg^(0)from waste gases,with adsorbents serving as the prima... Mercury pollution is created by coal combustion processes in multi-component systems.Adsorbent injection was identified as a potential strategy for capturing Hg^(0)from waste gases,with adsorbents serving as the primary component.The hydro-thermal approach was used to synthesize a series of MnO_(x)-CeO_(x)nanorod adsorbents with varying Mn/Ce molar ratios to maximize the Hg^(0)capture capabilities.Virgin CeO,had weak Hg elimination activity;<8%Hg^(0)removal efficiency was obtained from 150℃to 250℃.With the addition of MnOr,the amount of surface acid sites and the relative concentration of Mn4+increased.This ensured the sufficient adsorption and oxidation of Hg while overcoming the limitations of restricted adsorbate-adsorbent interactions caused by the lower surface area,endowing MnO_(x)-CeO_(x)with increased Hg^(0)removal capac-ity.When the molar ratio of Mn/Ce reached 6/4,the adsorbent's Hg^(0)removal efficiency remained over 92%at 150℃and 200℃.As the molar ratio of Mn/Ce grew,the adsorbent's Hg^(0)elimination capacity declined due to decreased surface area,weakened acidity,and decreased activity of Mn^(4+);<75%Hg^(0)removal efficiency was reached between 150℃and 250℃for virgin MnOx.Throughout the overall Hg'elimination reactions,Mn4+and O.were in charge of oxidizing Hg^(0)to Hg^(0),with Ce^(4+)acting as a promoter to aid in the regeneration of Mn^(4+),Because of its limited adaptability to flue gas components,further optimization of the MnO_(x)-CeO_(x)nanorod adsorbent is required. 展开更多
关键词 Hg^(0)capture MnO_(x)-CeO_(x)nanorods Mn/Ce molar ratio Acid properties Redox behaviors
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Low-Cost Preparation of Boron Nitride Ceramic Powders 被引量:1
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作者 李端 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第3期534-537,共4页
The amorphous boron nitride ceramic powders were prepared at 750-950 ℃ by the low-cost urea route, and the effects of preparation temperatures, molar ratios of the raw materials and oxidation treatment on the composi... The amorphous boron nitride ceramic powders were prepared at 750-950 ℃ by the low-cost urea route, and the effects of preparation temperatures, molar ratios of the raw materials and oxidation treatment on the composition, structure and surface morphology of the products were investigated through FT-IR, XRD and SEM. The results show that the products ceramize and crystallize gradually with the increase of the temperature. When the molar ratio and reaction temperature are 3:2 and 850 ℃, respectively, the products have high purity, compact structure and nice shape. The oxidation treatment at 450 ℃ will not impair the composition and structure of boron nitride but effectively remove the impurities. 展开更多
关键词 LOW-COST urea route boron nitride ceramic molar ratios of the raw materials preparation temperatures oxidation treatment
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High Performance of Fly Ash Derived Li <sub>4</sub>SiO<sub>4</sub>-Based Sorbents for High Temperature CO<sub>2</sub>Capture
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作者 Shenggen Wu Xiaoli Liang +1 位作者 Qi Zhang Guiru Zhang 《Journal of Encapsulation and Adsorption Sciences》 2021年第1期1-17,共17页
It is urgent to develop excellent solid CO<sub>2</sub> sorbents with higher sorption capacity, simpler synthetic process, better thermal stability and lower costs of synthesis in CO<sub>2</sub>... It is urgent to develop excellent solid CO<sub>2</sub> sorbents with higher sorption capacity, simpler synthetic process, better thermal stability and lower costs of synthesis in CO<sub>2</sub> capture and storage technologies. In this work, a number of Li<sub>4</sub>SiO<sub>4</sub>-based sorbents synthesized by lithium carbonate with three different kinds of fly ashes in various molar ratios were developed. The results indicate that the Li<sub>2</sub>CO<sub>3</sub>:SiO<sub>2</sub> mole ratio used in the sorbents synthesis significantly affects the CO<sub>2</sub> absorption properties. The sorption capacity increased with the excess of Li<sub>2</sub>CO<sub>3</sub> first and then decreased when the excessive quantity was beyond a certain amount. The experiments found that FA-Li<sub>4</sub>SiO<sub>4</sub>_0.6, CFA-Li<sub>4</sub>SiO<sub>4</sub>_0.4, HCl/CFA-Li<sub>4</sub>SiO<sub>4</sub>_0.3 presented the best sorption ability among these fly ash derived Li<sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;">SiO</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> samples, and the corresponding weight gain was 28.2 wt%, 25.1 wt% and 32.5 wt%, respectively. The three sorbents with the optimal molar ratio were characterized using various morphological </span><span style="font-family:Verdana;">characterization techniques and evaluated by thermogravimetric analysis </span><span style="font-family:Verdana;">for their capacity to chemisorb CO<sub>2</sub> at 450<sup></sup></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&deg</span></span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">C</span><span style="font-family:Verdana;"> - 650<sup></sup></span><span style="font-family:Verdana;"><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&deg</span></span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">C</span><span style="font-family:Verdana;">, diluted CO<sub>2</sub> (10%, 20%) and in presence of water vapor (12%). The adsorption curve of FA- Li<sub>4</sub>SiO<sub>4</sub>_0.6 at different temperatures was simulated with the Jander-Zhang model to explore the influence of carbon dioxide diffusion on adsorption reaction. Further experiments showed that the adsorbent had a good sorption capacity in a lower partial pressure of CO<sub>2</sub> and the presence of steam enhanced the mobility of Li<sup>+</sup>. What’s more, FA-Li<sub>4</sub>SiO<sub>4</sub>_0.6, CFA-Li<sub>4</sub>SiO<sub>4</sub>_0.4 and HCl/CFA-Li<sub>4</sub>SiO<sub>4</sub>_0.3 particles showed satisfactory sorption capacity in fixed-bed reactor and excellent cyclic sorption stability during 10 sorption/ desorption cycles.</span></span></span></span> 展开更多
关键词 Fly Ash Lithium Orthosilicates molar ratios CO2 Capture
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Chemical equilibrium controlled synthesis of polyoxymethylene dimethyl ethers over sulfated titania 被引量:18
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作者 Huaju Li Huanling Song +2 位作者 Feng Zhao Liwei Chen Chungu Xia 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第2期239-244,共6页
The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers (DMMn) were investigated over sulfated titania in order to reveal the decisive factor controlling the react... The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers (DMMn) were investigated over sulfated titania in order to reveal the decisive factor controlling the reaction. The results showed that the molar ratio of adjacent DMMn products in equilibrium solution had the same value, which depended absolutely on the reaction temperature. Meanwhile, the reactions had the same DMMn products distributions under varied reaction conditions. The equilibrium constants of the related step-wise reactions for DMMn formation were equal, which were calculated based on the bulk compositions of the reaction solution. And thus, the selectivity to DMMn was mainly controlled by the chemical equilibrium, i.e., thermodynamic control. In brief, the present results provide some guidance for future synthesis of DMMn. 展开更多
关键词 polyoxymethylene dimethyl ethers sulfated titania chemical equilibrium reaction kinetic molar ratio
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Formation and Characteristics of Acrylonitrile/Urea Inclusion Compound
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作者 邹均庭 王雨松 +2 位作者 庞文民 石磊 鲁非 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第2期198-202,I0004,共6页
The formation process and composition of the acrylonitrile/urea inclusion compounds (AN/UIC) with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry (DSC) and X-ra... The formation process and composition of the acrylonitrile/urea inclusion compounds (AN/UIC) with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It is suggested that DSC can determine the guest/host ratio and the heat of decomposition. Meanwhile, the guest/host ratio and heat of decomposition are obtained, which are 1.17 and 5361.53 J/mol, respec- tively. It is suggested AN molecules included in urea canal lattice may be packed flat against each other. It is found that the formation of AN/UIC depends on the aging time. XRD results reveal that once AN molecules enter urea lattice, AN/UIC are formed, which possess the final structure. When AN molecules are sufficient, the length of AN molecular arrays in urea canals increases as aging time prolonging until urea tunnels are saturated by AN. 展开更多
关键词 ACRYLONITRILE Urea inclusion compound molar ratio Heat of decomposition Formation process
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Higher alcohol synthesis over Cu-Fe composite oxides with high selectivity to C_(2+)OH 被引量:12
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作者 Zhenghong Bao Kang Xiao +5 位作者 Xingzhen Qi Xinxing Wang Liangshu Zhong Kegong Fang Minggui Lin Yuhan Sun 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第1期107-113,共7页
Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product... Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity (GHSV) on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon. 展开更多
关键词 higher alcohol synthesis SYNGAS Cu-Fe composite oxides molar ratio GHSV
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Laboratory-scale study of the suppression of PCDD/F emission during coal and MSW co-incineration 被引量:4
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作者 LU Sheng-yong YAN Jian-hua LI Xiao-dong NI Ming-jiang CEN Ke-fa 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第6期762-767,共6页
The experimental test of co-incinerating Chinese raw municipal solid waste (MSW) and coal in a laboratory-scale tubular reactor was first reported in present study, and the emission of normal gas components and the ... The experimental test of co-incinerating Chinese raw municipal solid waste (MSW) and coal in a laboratory-scale tubular reactor was first reported in present study, and the emission of normal gas components and the effects of the S/Cl molar ratio or coal mixing percentages on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs) emission were investigated and discussed. The results indicated that OCDD was the only PCDD homologues since others like TCDD-HpCDD was hardly detected, while as the categories of PCDF homologues were comparatively much more general. The amount of PCDD was much larger than that of PCDF in all operating conditions. Since ZPCDF/∑PCDD〈〈1, the dominant role of the precursor formation was proven in our experimental conductions. With increasing the coal addition to MSW (from 0 to 16%), PCDD and PCDF were reduced considerably. Coal and MSW may suppress the PCDD/F emissions efficiently (over 95%) during the MSW incineration process. The PCDD/F suppression results of the present study could be helpful guidance to the industrial application of Chinese MSW and auxiliary coal co-incineration processes. The PCDD/F stack emission data of two industrial incinerators using co-incineration technology in China seem to have a great positive reduction of PCDDs/Fs. 展开更多
关键词 co-incineration PCDDs/Fs SUPPRESSION S/Cl molar ratio
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Characteristics of nutrients in the Jiulong River and its impact on Xiamen Water, China 被引量:3
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作者 陈宝红 暨卫东 +4 位作者 陈金民 林彩 黄海宁 霍云龙 纪贤标 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第5期1055-1063,共9页
Water samples were collected at 20 sites on 4 occasions in 2009 (twice in May, and once in both August and November) along the Jiulong River, South China to examine how nutrient inputs from the Jiulong River could a... Water samples were collected at 20 sites on 4 occasions in 2009 (twice in May, and once in both August and November) along the Jiulong River, South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water. Samples were analyzed for nitrite (NO2-N), nitrate (NO3-N), ammonium (NH4-N), phosphate (PO4-P), silicate (SiO3-Si), salinity, and temperature, to determine the nutrient and trophic status of the river. The results indicate that nutrients are derived mainly from river runoff. NO3-N was the main form of DIN in most parts of the river. In addition, NO3-N, DIN, and SiO3-Si behave conservatively. There is a surplus of DIN and SiO3-Si in the river, and PO4-P is a limitation on phytoplankton growth. The concentration of DIN is typically above 0.60 mg/dm3, and higher than 1.00 mg/dm3 in most parts of the river. The concentration of PO4-P is typically above 0.02 mg/dm3, while the concentration of SiO3-Si is higher than 1.00 rag/din3. Between 2003 and 2008, samples were collected 3 times per year (May, August and November) at 27 sites in the Xiamen Water and analyzed for NO2-N, NO3-N, NH4-N, PO4-P, salinity, and temperature. We discovered that the Jiulong River was the key source of DIN into the Xiamen Water, but not PO4-P, indicating the reason of the N/P molar ratio imbalance in the Xiamen Water. In the future, the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied. 展开更多
关键词 NUTRIENT molar ratio EUTROPHICATION N enrichment the Jiulong River
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Low-Temperature Selective Catalytic Reduction of NO with NH_3 over Fe–Ce–O_x Catalysts 被引量:5
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作者 Yan Sun Ying Guo +1 位作者 Wei Su Yajuan Wei 《Transactions of Tianjin University》 EI CAS 2017年第1期35-42,共8页
In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of ... In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of NO using NH<sub>3</sub>. We investigated the effects of Fe/Ce molar ratio, the gas hourly space velocity (GHSV), the stability and SO<sub>2</sub>/H<sub>2</sub>O resistance of the catalysts. The results showed that the FeCe(1:6)O<sub> x </sub> (Ce/Fe molar ratio is 1:6) catalyst, which has some ordered parallel channels, exhibited good SCR performance. The FeCe(1:6)O<sub> x </sub> catalyst had the highest NO conversion with an activity of 94-99% at temperatures between 200 and 300 °C at a space velocity of 28,800 h<sup>−1</sup>. The NO conversion for the FeCe(1:6)O<sub> x </sub> catalyst also reached 80-98% between 200 and 300 °C at a space velocity of 204,000 h<sup>−1</sup>. In addition, the FeCe(1:6)O<sub> x </sub> catalyst demonstrated good stability in a 10-h SCR reaction at 200-300 °C. Even in the presence of SO<sub>2</sub> and H<sub>2</sub>O, the FeCe(1:6)O<sub> x </sub> catalyst exhibited good SCR performance. 展开更多
关键词 Fe-Ce-O x Low-temperature selective catalytic reduction Fe/Ce molar ratio Gas hourly space velocity Stability SO2/H2O resistance
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Direct synthesis of hydrogen peroxide over Pd nanoparticles embedded between HZSM-5 nanosheets layers 被引量:3
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作者 Guozhu Liu Hairui Liang +2 位作者 Yajie Tian Bofeng Zhang Li Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第10期2577-2586,共10页
Direct synthesis of hydrogen peroxide(DSHP)was studied over Pd loaded on HZSM-5 nanosheets(Pd/ZN).Pd nanoparticles with average size of ca.4.3 nm were introduced into the adjacent nanosheet layers(thickness of ca.2.9 ... Direct synthesis of hydrogen peroxide(DSHP)was studied over Pd loaded on HZSM-5 nanosheets(Pd/ZN).Pd nanoparticles with average size of ca.4.3 nm were introduced into the adjacent nanosheet layers(thickness of ca.2.9 nm)by impregnation method.Pd/ZN with theoretical Si/Al molar ratio of 25 showed the highest selectivity for H2O2 among the prepared catalysts,together with highest formation rate of H2O2(38.0 mmol·(g cat)^-1·h^-1),1.9 times than that of Pd supported on conventional HZSM-5 zeolite(Pd/CZ-50).Better catalytic performance of nanosheet catalysts was attributed to the promoted Pd dispersion which promoted H2 dissociation,more BrΦnsted acid sites and stronger metal-support interaction which inhibited the dissociation of O-O bond in H2O2.The embedded structure sufficiently protected the Pd nanoparticles by space confinement which restrained the Pd leaching,leading to a better catalytic stability with 90%activity retained after 3 cycles,which was almost 3 times than that of Pd/CZ-50(30.4%activity retained). 展开更多
关键词 HZSM-5 nanosheets Palladium catalyst Silica/alumina molar ratio Metal-support interaction Direct synthesis of hydrogen peroxide
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Production of polyhydroxybutyrate by the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 被引量:2
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作者 才金玲 魏莹 +2 位作者 赵宇鹏 潘光华 王广策 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期620-626,共7页
The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of ... The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation (8.10±0.09 g/L) and PHB production (1.11±0.13 g/L and 14.62%±2.25% of the cell dry weight) were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH^-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration (7.65±0.05 g/L) was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB (5.03±0.18 g/L and 66.93%± 1.69% of the cell dry weight) was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation (8.77±0.58 g/L) and PHB production (6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight) was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield. 展开更多
关键词 POLYHYDROXYBUTYRATE Rhodovulum sulfidophilum nitrogen source carbon source carbon tonitrogen molar ratio
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Influence of Reaction Conditions on Methanol Synthesis and WGS Reaction in the Syngas-to-DME Process 被引量:2
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作者 Ligang Wang Deren Fang +3 位作者 Xingyun Huang Shigang Zhang Yue Qi Zhongmin Liu 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2006年第1期38-44,共7页
A series of CuO-ZnO catalysts (with different Cu/Zn molar ratios) were prepared, and evaluated under the reaction conditions of syngas-to-dimethyl ether (DME) with three sorts of feed gas and different space veloc... A series of CuO-ZnO catalysts (with different Cu/Zn molar ratios) were prepared, and evaluated under the reaction conditions of syngas-to-dimethyl ether (DME) with three sorts of feed gas and different space velocity. The catalysts were characterized by X-ray diffraction (XRD) and temperatureprogrammed reduction (TPR). The experiment results showed that the reaction conditions of syngas-to- DME process greatly affected the methanol synthesis and WGS reaction. The influence caused by Cu/Zn molar ratio was quite different on the two reactions; increasing of percentage of CO2 in feed gas was unfavorable for catalyst activity, and also inhibited both reactions; enhancement of reaction space velocity heavily influenced the performance of the catalyst, and the benefits were relatively less for methanol synthesis than for the WGS reaction. 展开更多
关键词 copper zinc Cu/Zn molar ratio METHANOL dimethyl ether water gas shift reaction SYNGAS DEHYDRATION
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Dimethoxymethane production via CO_(2)hydrogenation in methanol over novel Ru based hierarchical BEA 被引量:2
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作者 Waqar Ahmad Fan Liang Chan +3 位作者 Abhijit Shrotri Yayati Naresh Palai Huanting Wang Akshat Tanksale 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第3期181-189,I0006,共10页
Dimethoxymethane(DMM),a diesel blend fuel,is being researched with high interest recently due to its unique fuel properties.It is commercially produced via a two step-process of methanol oxidation to make formaldehyde... Dimethoxymethane(DMM),a diesel blend fuel,is being researched with high interest recently due to its unique fuel properties.It is commercially produced via a two step-process of methanol oxidation to make formaldehyde,followed by its condensation with methanol.This study presents a one-pot method of DMM synthesis from methanol mediated carbon dioxide hydrogenation over novel heterogeneous catalysts.The effect of catalyst pore structure was investigated by synthesizing 3 wt%Ru over novel hierarchical zeolite beta(HBEASX)and comparing against Ru doped commercial zeolite beta(CBEA)and desilicated hierarchical zeolite beta(HBZDS).The results showed that 3%Ru/HBEASX provided the best activity for DMM production due to its large average pore size.It also showed the decisive role of SiO_(2)/Al_(2)O_(3)molar ratio,with SiO_(2)/Al_(2)O_(3)=75 providing the highest DMM yield of 13.2 mmol/gcat.LMeOH with ca.100%selectivity.The activity of 3%Ru/HBEAS3 after 5 recycle steps demonstrated the reusability of this catalyst. 展开更多
关键词 DIMETHOXYMETHANE Methanol solvent CO_(2)hydrogenation Hierarchical BEA SiO_(2)/Al_(2)O_(3)molar ratio Ru catalysts
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Hydrothermal Synthesis,Structure and Characterization of a New 2D Co(Ⅱ) Coordination Polymer Based on Flexible Double Imidazole Derivative and Oxalate 被引量:1
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作者 LIU Lian-li HUANG Jing-jing WANG Xiu-li LIU Guo-cheng YANG Song MU Bao 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第6期942-946,共5页
A 1D supramolecular compound [dmbbbi](1) and a 2D cobalt coordination polymer [Co(dmbbbi)(ox)] 2(2) [dmbbbi=1,1-(1,4-butanediyl)bis(5,6-dimethylbenzimidazole),ox=oxalate],C48H52Co2N8O8,were obtained under ... A 1D supramolecular compound [dmbbbi](1) and a 2D cobalt coordination polymer [Co(dmbbbi)(ox)] 2(2) [dmbbbi=1,1-(1,4-butanediyl)bis(5,6-dimethylbenzimidazole),ox=oxalate],C48H52Co2N8O8,were obtained under hydrothermal conditions by tuning the molar ratio of the reactants.The crystal structure analysis reveals that in compound 1,the adjacent dmbbbi molecules connect with each other via hydrogen bonds to form a 1D supramolecular chain.In compound 2,two crystallographically independent Co2+ ions show the same six-coordination mode.Each Co2+ ion is coordinated by four oxygen atoms from two ox anions and two nitrogen atoms from two cis-dmbbbi ligands.The adjacent Co2+ ions are bridged by ox anions to generate an infinite 1D zigzag chain,which is extended by pairs of dmbbbi ligands to form a 2D honeycomb-like(6,3) network.Moreover,the thermal stability and the electrochemical property of compound 2 were studied. 展开更多
关键词 Hydrothermal synthesis Crystal structure molar ratio Double imidazole derivative
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