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Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles

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Journal of Thermal Science 2025年第1期34卷 24-33页

作者： LIN Yongjie ZHANG Cancan WU Yuting ZHANG Yi LU Yuanwei Key Laboratory of Heat Transfer and Energy Conversion National User-Side Energy Storage Innovation Research and Development CenterBeijing University of Technology

Numerical simulations of the flow and heat transfer characteristics of four shell-and-tube molten salt electric heaters with different perforation rates was ***-and-tube electric heaters have the same geometry and tube arrangement,and all of them use single segmental baffles,but there exist four different baffle openings（φ）,i.e.,0%,2.52%,4.06%,and 6.31%.The results indicated that the reasonable baffle opening could significantly reduce the shell-side pressure drop,effectively decreasing the shell-side flow dead zone *** can eliminate the local high-temperature phenomenon on the surface of electric heating tubes,but the heat transfer coefficient is slightly *** perforated schemes significantly reduce shell-side pressure drop compared to the baseline solution without open *** particular,the φ=6.31% scheme exhibits the optimal performance among all the schemes,with a maximum reduction of up to 50.50% in shell-side pressure drop relative to the unopened holes *** heat transfer coefficient is the highest for φ=0%,exhibiting a range of5.26% to 5.73%,5.14% to 5.99%,and 7.31% to 8.54% higher than φ=2.52%,4.06%,and 6.31%,respectively,within the calculated *** composite index h/（Δp）1/3was higher for all open-hole solutions than that for the unopened-hole *** best overall performance was for φ=6.31%,which improved the composite index by15.29% to 17.18% over the unopened-hole solution.

关键词： molten salt electric heater perforated baffles heat transfer

Synthesis of β-(1→6)-Branched (1→3)-Glucononaoside with Alternate β-and α-Bonds in the Backbone

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Chinese Journal of Chemistry 2003年第12期21卷 1655-1660页

作者：吴自成宁君孔繁祚 research center for eco-environmental Sciences Chinese Academy of Sciences

Lauryl glycoside of β-D-Glcp-(1→3)-[β-D-Glcp-(1→6)-]α-D-Glcp-(1→3)-β-D-Glcp-(1→3)-[β-D-Glcp-(1→6)-]α-D-Glcp-(1→3)-β-D-Glcp-(1→3)-[β-D-Glcp-(1→6)-]β-D-Glcp was synthesized through 3+3+3 strategy. 3-O-Allyl-2,4,6-tri-O-benzoyl-β-D-glucopyranosyl-(1→3)-[2,3,4,6-tetra-O-benzoyl-β-D-glucopyranosyl-(1→6)-] 1,2 -O-isopropylidene-α-D-glucofuranose was used as the key intermediate which was converted to the corresponding trisaccharide donor and acceptor readily.

关键词： oligosaccharide synthesis glucose

Constructing Pr-doped CoOOH catalytic sites for efficient electrooxidation of 5-hydroxymethylfurfural

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Journal of Energy Chemistry 2025年第1期100卷 234-244页

作者： Botao Fan Hao Zhang Bang Gu Feng Qiu Qiue Cao Wenhao Fang School of Chemical Science and Technology Yunnan University National center for International research on Photoelectric and Energy Materials School of Materials and Energy Yunnan University

Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high current ***,a Pr-doped Co（OH）2hexagonal sheet （Pr/Co=1/9,in mole） is synthesized by electrodeposition as highly performant catalyst for 5-hydroxymethylfurfural （HMF） oxidation reaction（HMFOR） to produce 2,5-furandicarboxylic acid （FDCA）.This novel and low-cost catalyst possesses a rather low onset potential of 1.05 V （***） and requires only 1.10 V （***） to reach a current density of 10 mA cm-2for HMFOR,significantly outperforming Co（OH）2benchmark (i.e.,210 mV higher to reach10 m A cm-2).The origin of Pr promotion effect as well as the evolution of CoOOH catalytic sites and HMFOR process has been deeply elucidated by physical characterizations,kinetic experiments,in situ electrochemical techniques,and theoretical *** unique Pr-ameliorated CoOOH active centers enable 100%conversion of HMF,99.6%selectivity of FDCA,and 99.7%Faraday efficiency,with a superior cycling durability toward *** can be one of the most outstanding results for Co-based HMFOR catalysts to date in the *** this work can help open up new horizons for constructing novel and efficient Co-based electrocatalysts by the utilization of lanthanide elements.

关键词： Bioconversion

Acute and chronic effects of tributyltin on the Chinese rare minnow(Gobiocypris rarus)

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Science China Chemistry 2003年第3期46卷 243-251页

作者：周群芳江桂斌刘稷燕 research center for eco-environmental Sciences Chinese Academy of Sciences

The acute (12 h) and chronic (7 or 14 d) effects of tributyltin chloride (TBT) on a new type of test fish, the Chinese rare minnow (Gobiocypris rarus), have been studied. High accumula-tion of the pollutant in the fish muscle and obvious changes in hepatosomatic index and gonad somatic index were observed after exposure. The ultrastructural findings show a series of patho-logical changes existing in the exposed gill cells and hepatocytes, which demonstrates the toxicity effects of tributyltin compounds on aquatic organisms. The results clearly show that the Chinese rare minnow is a new sensitive test fish material, whose exposure system is suitable for the exten-sive organometallic toxicity studies.

关键词： tributyltin Chinese rare minnow toxicology

Effects of acid deposition on terrestrial ecosystems and their rehabilitation strategies in China

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Journal of environmental Sciences 2002年第2期14卷 227-233页

作者： FENG Zong\|wei, MIAO Hong, ZHANG Fu\|zhu, HUANG Yi\|zong (research center for eco\|environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. E\|mail: FZW@***) research center for eco-environmental Sciences Chinese Academy of Sciences 北京 100085

South China has become the third largest region associated with acid deposition following Europe and North America, the area subject to damage by acid deposition increased from 1.75 million km 2 in 1985 to 2.8 million km 2 in 1993. Acid deposition has caused serious damage to ecosystem. Combined pollution of acid rain and SO 2 showed the obvious multiple effects on crops. Vegetable was more sensitive to acid deposition than foodstuff crops. Annual economic loss of crops due to acid deposition damage in eleven provinces of south China was 4.26 billion RMB Yuan. Acid deposition caused serious damage to forest. Annual economic loss of wood volume was about 1.8 billion RMB Yuan and forest ecological benefit loss 16.2 billion in eleven provinces of south China. Acid deposition in south China was typical “sulfuric acid type”. According to the thoughts of sustainable development, some strategies were brought forward as follows: (1) enhancing environmental management, specifying acid\|controlling region, controlling and abating the total emission amount of SO 2; (2) selecting practical energy technologies of clean coal, for example, cleansing and selecting coal, sulfur\|fixed\|type industrial briqutting, abating sulfur from waste gas and so on; (3) developing other energy sources to replace coal, including water electricity, atomic energy and the new energy such as solar energy, wind energy and so on; (4) in acid deposition region of south China, selecting acid\|resistant type of crop and tree to decrease agricultural losses, planting more green fertilizer crops, using organic fertilizers and liming, in order to improve buffer capacities of soil.

关键词： acid rain agriculture forestry economic loss rehabilitation strategies

Hydrological eco-service of rubber plantations in Hainan Island and its effect on local economic development

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Journal of environmental Sciences 2003年第5期15卷 701-709页

作者： JIANG Ju sheng , WANG Ru song (research center for eco environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. research center for eco-environmental Sciences Chinese Academy of Sciences 北京 100085

The impacts of economic forest on global environmental change(GEC) are one of the hot issues in environmental study. Based on the 3 year observation data and 40 year climate data, GEC and analysis of the hydrological dynamic characteristics of rubber plantations and estimate of the water balance in the rubber plantations in Hainan Island were made. The results showed that the rainfall intercepted by the canopy of the plantations accounted for 11 45% of the annual rainfall, the total runoff for 23 71%, the total evaporation and transpiration for 63 24%, the soil moisture storage for 1 6%. Analysis of the 40 year rainfall data in the 19 counties of Hainan Island during 1951—1990 showed that the large scale substitution of the natural vegetation with the rubber plantations had no significant effect on the local rainfall in Hainan Island. The main reasons are (1) 80% of the rainfall in Hainan is brought by typhoons; (2) the proportion of 11 6% rubber plantations in total forest coverage in Hainan is not enough to influence the local rainfall in Hainan Island; and (3) although the rubber plantation is artificial vegetation, it has the similar function to the tropical rain forest. Analysis of the total water resource and total GDP of Hainan in 1997 showed that the economic benefit resulted from the water resource was 1 0 RMB Yuan/m 3 The value of hydrological of the rubber plantation in Hainan was 113 9 million RMB Yuan/a when compared with the tropical rain forest. The paper reaches conclusion that the hydrological eco service function of rubber plantation has been enhanced after transformed from natural vegetation, which includes the natural service and powerful social service.

关键词： eco service rubber plantation hydrological function Hainan Island

Investigation of Mixed Chiral Selectors of Different Metal Ion-L-Alanine Complex and β-Cyclodextrin on the Chiral Separation of Dansyl Amino Acids with Capillary Electrophoresis

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Chinese Journal of Chemistry 2003年第11期21卷 1478-1484页

作者：郑志侠屈锋林金明 research center for eco-environmental Sciences Chinese Academy of Sciences

Chiral separation of dansyl amino acids by capillary electrophoresis using mixed selectors of Mn(II)- L -alanine complex and β -cyclodextrin ( β -CD) was studied. Resolution was considerably superior to that obtained by using either Mn(II)- L -alanine complex or β -CD alone. The effects of separation parameters,such as pH value of buffer solution,capillary temperature,the concentration of Mn(II)- L -alanine complex,the types of CD and ligand on the migration times and resolutions were investigated. Six different transition metal complexes, Cu(II), Zn(II),Co(II),Ni(II),Hg(II) and Cd(II)- L -alanine complexes have been employed and compared with Mn(II) complex. Differences in retention and selectivity were found. The substitution of Cu(II),Zn(II),Co(II) and Ni(II) for Mn(II) resulted in a better chiral resolution while Hg(II) and Cd(II) showed poorer resolution abilities. The chiral separation mechanism was also discussed briefly.

关键词： chiral separation ligand-exchange capillary electrophoresis dansyl amino acids β-cyclodextrin

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil

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Journal of environmental Sciences 2002年第4期14卷 524-529页

作者： YE Chang ming, WANG Xing jun, ZHENG He hui (research center for eco environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. research center for eco-environmental Sciences Chinese Academy of Sciences 北京 100085

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil SDBS (sodium dodecylbenzene sulfonate) mixtures and soil HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half life of acetochlor and butachlor in soil alone, soil SDBS mixtures and soil HA mixtures were 4.6d, 6.1d and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2 methyl 6 ethylaniline for acetochlor, and hydroxybutachlor and 2,6 diethylaniline for butachlor.

关键词： acetochlor butachlor soil biodegradation kinetics degradation products

Adsorption-desorption behavior of acetochlor to soils in the presence of some environmental substances

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Journal of environmental Sciences 2002年第2期14卷 269-276页

作者： YE Chang ming, LEI Zhi fang (research center for eco environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. research center for eco-environmental Sciences Chinese Academy of Sciences 北京 100085

The behavior of herbicide acetochlor adsorption desorption to soil in the presence of humic acid (HA), anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant hexadecyltrimethyl ammonium bromide (HDAB) and NH 4NO 3 as a chemical fertilizer was studied. Observed acetochlor adsorption isotherm were well described using Freundlich isotherm equation, from which the desorption isotherm equation has been deduced. The deduced equation can more directly describe acetochlor desorption process. The results showed that the enhance of acetochlor adsorption capacity by solid HA was greater than by soluble HA. The presence of NH 4NO 3 can slightly enhance acetochlor adsorption to soil by comparison with that measured in NH 4NO 3 free solution. In soil water system, surfactant acetochlor interaction is very complex, and the surfactant adsorptions as well as acetochlor adsorption need to be considered. When acetochlor soil suspensions contained lower concentration SDBS or HDAB (40 mg/L), K f for acetochlor adsorption was decreased in comparison to that measured in SDBS or HDAB free solution. When acetochlor soil suspensions contained higher concentration SDBS or HDAB (corresponding 1400 mg/L or 200 mg/L), K f for acetochlor adsorption was increased in comparison to that measured in SDBS or HDAB free solution.

关键词： adsorption desorption acetochlor humic acid surfactants ammonium nitrate soil