检索结果-南通市图书馆

Perchlorate removal using granular activated carbon supported iron compounds: Synthesis, characterization and reactivity

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第11期22卷 1807-1813页

作者： Jianhong Xu Naiyun Gao Yulin Tang Yang deng Minhao sui State Key Laboratory of Pollution Control and Resource Resue Tongji University Shanghai 200092 China Jiangxi University of Science and Technology Ganzhou 341000 China Department of Earth and Environmental Studies Montclair State University Montclair New Jersey 07043 USA

Synthesis and use of the iron compounds supported on granular activated carbon （ICs/GAC） have shown significant environmental implications for perchlorate （ClO4^- ） removal. ICs/GAC was synthesized via hydrolyzing FeSO 4 ·7H2O on GAC, reduced by NaBH 4 solution in polyethylene glycol 6000 and ethanol solution, dried in vacuum condition and exposed to air. Synthesized ICs/GAC was characterized using transmission electron micrograph （TEM）, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy （XPS）. ICs/GAC was determined to be containing a large amount of FeOHSO 4 , Fe2O3 and a small amount of zero-valent iron （ZVI） nanoparticles according to TEM and XPS measurements. Batch static kinetic tests showed that 97% of ClO4^- was removed within 10 hr at 90°C and 86% of ClO4^- was removed within 12 hr at 25°C, at ICs/GAC dosage of 20 g/L. The experimental results also showed that FeOHSO 4 and Fe 2 O 3 nanoparticles have the function of perchlorate adsorption and play important roles in ClO4^- removal. The activation energy （E a ） was determined to be 9.56 kJ/mol.

关键词： perchlorate removal ICs /GAC activation energy synthesis

Advances in the construction of diverse SuFEx linkers

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第6期10卷 226-244页

作者： Daming Zeng Wei-ping deng Xuefeng Jiang Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism School of Pharmacy East China University of Science and Technology Shanghai Key Laboratory of Green Chemistry and Chemical Process School of Chemistry and Molecular Engineering East China Normal University

Sulfur fluoride exchange(SuFEx),a new generation of click chemistry,was first presented by Sharpless,Dong and co-workers in *** to the high stability and yet efficient reactivity of the SⅥ-F bond,SuFEx has found widespread applications in organic synthesis,materials science,chemical biology and drug discovery.A diverse collection of SuFEx linkers has emerged,involving gaseous SO2F2and SOF4hubs;SOF4-derived iminosulfur oxydifluorides;O-,N-and C-attached sulfonyl fluorides and sulfonimidoyl fluorides;and novel sulfondiimidoyl *** review summarizes the progress of these SuFEx connectors,with an emphasis on analysing the advantages and disadvantages of synthetic strategies of these connectors based on the SuFEx concept,and it is expected to be beneficial to researchers to rapidly and correctly understand this field,thus inspiring further development in SuFEx chemistry.

关键词： SuFEx SuFEx linker SVI–F bond synthetic strategy

Microstructure and room-temperature tensile property of Ti-5.7Al-4.0Sn-3.5Zr-0.4Mo-0.4Si-0.4Nb-1.0Ta-0.05C with near equiaxed β grain fabricated by laser directed energy deposition technique

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第6期101卷 308-320页

作者： MengCheng deng Shang sui Bo Yao Liang Ma Xin Lin Jing Chen State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’an 710072China

Near-equiaxed β grain was achieved in the near-α Ti60(Ti-5.7Al-4.0Sn-3.5Zr-0.4Mo-0.4Si-0.4Nb-1.0Ta-0.05C) titanium alloy via laser directed energy deposition(LDED). The microstructural evolution along the building direction and the room-temperature tensile properties along the horizontal and vertical directions(building direction) were systematically studied through SEM and OM. EBSD and XRD were utilized to accurately demonstrate the texture of the α and β phases. The results showed that the α phase presented a low texture intensity, which was ascribed to the weak textured β grain with near-equiaxed morphology, since there are Burgers orientation relationships during the β →α transition. In addition, numerical simulation, combined with the CET curve of Ti60 alloy considering the effect of multi-composition,was utilized to elucidate the formation mechanism of the near-equiaxed β grains. Furthermore, according to the solidification theory, we proposed that the solidification temperature range ΔTfwas more accurate than the growth restriction factor Q in predicting the formation tendency of equiaxed β grain in different titanium alloys. Tensile results showed that the horizontal and vertical samples had similar strength,while the former exhibited larger elongation than the latter. The effect of the near-equiaxed β grain and the internal α phase on mechanical properties were revealed at last.

关键词： Laser directed energy deposition Near-αtitanium alloy Equiaxedβgrain Room-temperature tensile property

Dimethylacetamide-promoted Direct Arylation Polycondensation of 6,6’-Dibromo-7,7’-diazaisoindigo and(E)-1,2-bis(3,4-difluorothien-2-yl)ethene toward High Molecular Weight n-Type Conjugated Polymers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2019年第11期37卷 1099-1104页

作者： Kai Guo Yu Jiang Ying sui Yun-Feng deng Yan-Hou Geng School of Materials Science and Engineering Tianjin University Tianjin 300072 China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Tianjin Key Laboratory of Molecular Optoelectronic Science Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China

A highly efficient and eco-friendly protocol for the synthesis of an alternating copolymer poly(7,7'-diazaisoindigo-alt-(E)-1,2- bis(3,4-difluorothien-2-yl)ethene)(PAIID-4FTVT) via direct arylation polycondensation (DArP) is presented. Through detailed study, we found that the inhibitory effect of 7,7'-diazaisoindigo on DArP stemmed from the coordination of N atom with catalyst can be overcome by using dimethylacetamide (DMAc) as the co-solvent. Thus, PAIID-4FTVT with number-average molecular weight (Mn)>100kDa was synthesized via DArP by optimizing the content of DMAc. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy revealed that PAIID-4FTVT was defect-free. Top gate and bottom contact (TG/BC) organic thin-film transistors (OTFTs) were fabricated to characterize the semiconducting properties of the polymers. PAIID-4FTVT displayed unipolar n-type characteristics with the electron mobility (μe) strongly dependent on Mn. The highest μe up to 0.25 cm^2·V^-1 s^-1 was achieved with the high molecular weight sample.

关键词： Direct arylation polycondensation Conjugated polymer 7,7-Diazaisoindigo Organic thin-film transistor Electron mobility

Distribution and deposition of polycyclic aromatic hydrocarbons in precipitation in Guangzhou, South China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第5期21卷 654-660页

作者： HUANG Deyin PENG ping'an XU Yigang deng Yunyun deng Hongmei State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control Guangdong Institute of Eco-environment and Soil Sciences Guangzhou 510650 China Graduate University of Chinese Academy of Sciences Beijing 100039 China Key Laboratory of lsotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Polycyclic aromatic hydrocarbons （PAHs） were measured in precipitation from March to August 2005 in Guangzhou, South China. Fourteen PAHs were studied, and their total concentrations varied from 616.6 to 3486.7 ng/L in dissolved phase and from 403.8 to 3125.5 ng/L in particulate phase. The estimated deposition loading of PAHs was 3568 ug/m^2 during the monitoring period. The deposition of PAHs was a potential source for Pearl River comparing with the contents of surface water. In addition, the high concentration in precipitation here implied that PAHs pollution was a potential environmental problem in Guangzhou. Most precipitation concentrations of PAHs in March （the last month in winter in Guangzhou） were higher than in the other months （in rainy season）. PAHs inclined to be adsorbed to particulate phase with the increase of molecular weight in rainwater. Combustion of fossil fuel and biomass might be the major source of PAHs, while the direct leakage or volatilization from petroleum products might be insignificant.

关键词： polycyclic aromatic hydrocarbons distribution coefficient deposition flux precipitation Guangzhou

Species Composition, Richness and Aboveground Biomass of Natural Grassland in Hilly-Gully Regions of the Loess Plateau, China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2014年第11期13卷 2527-2536页

作者： deng Lei SHANGGUAN Zhou-ping State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University

In order to study the characteristics of species composition, richness and aboveground biomass of natural grasslands, and then ifnd out the relations between species richness and aboveground productivity of the communities and possible mechanisms to form the relations, four typical grassland communities （Artemisia capillaries （AC）, Thymus quinquecostatus （TQ）, Stipa bungeana （SB） and Stipa grandis （SG）） along with a succession sequence in hilly-gully regions of the Loess Plateau, China, were investigated by ifeld survey and laboratory analysis. The results were summarized as follows：Different succession stages had different species compositions as well as different proportions of plant life forms and photosynthetic types, and Asteraceae, Poaceae and Leguminosae were their dominant species as well as their dominant perennial herb species;and different succession stages had signiifcantly different species richness and aboveground biomasses. There were many relation patterns （linear positive correlation, unrelated relations and unimodal relations） between the species richness and aboveground biomass in different succession stages and a signiifcant unimodal relation between the species richness and aboveground biomass in all the grassland communities and the highest species diversity appeared at a moderate level of productivity. The results suggest the unimodal relations in all the grassland communities are accumulative results of the relations in each succession stage.

关键词： life forms photosynthetic types productivity species diversity

Rapid determination of pharmaceuticals from multiple therapeutic classes in wastewater by solid-phase extraction and ultra-performance liquid chromatography tandem mass spectrometry

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2009年第24期54卷 4633-4643页

作者： sui Qian HUANG Jun deng ShuBo YU Gang POPs Research Centre Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

A new analytical method utilizing ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) has been developed to determine 16 pharmaceuticals from 8 therapeutic classes in wastewater: bezafibrate, clofibric acid, carbamazepine, caffeine, chloramphenicol, diclofenac, gemfibrozil, indomethacin, ketoprofen, mefenamic acid, metoprolol, nalidixic acid, N,N-diethyl-metatoluamide, propranolol, sulpiride and trimethoprim. Key parameters of MS/MS, UPLC and solid phase extraction (SPE) were optimized. In general, recovery of target pharmaceuticals was over 70% for the wastewater effluent samples and 50% for the influent samples. The effects of matrix suppression, loss during the pretreatment as well as instrument variability were successfully corrected by two internal standards, and acceptable relative recovery was obtained. Target compounds were quantitatively analyzed using multiple reaction monitoring (MRM) mode, and the detection limits ranged from 0.3 to 20 ng/L. A detailed study, matrix effect in effluent wastewater was also present. The method was applied to detecting pharmaceuticals in the wastewater from three wastewater treatment plants (WWTPs) in Beijing, China and the results demonstrated that most target compounds were detectable in both the influent and effluent, with the mean concentrations ranging from 20.5 to 5775.6 ng/L and 4.6 to 418.6 ng/L, respectively.

关键词：高效液相色谱串联质谱法固相萃取废水药品快速测定治疗污水处理厂

在线全文

学校读者我要写书评

暂无评论

新冠疫情背景下苏宁易购的利润表研究

江苏商论 2025年第1期 11-14,52页

作者：隋佳轩杨西平西藏民族大学陕西咸阳712082

随着资本市场的不断发展和各种财务指标分析的完善,中国的财务分析方法日趋成熟,尤其是利润表方面的分析,与其有关的研究成果逐渐趋向于完善。由于苏宁易购在电商行业占据了极其重要的地位,所以利润表分析能够更清晰地披露苏宁易购在发... 详细信息

随着资本市场的不断发展和各种财务指标分析的完善,中国的财务分析方法日趋成熟,尤其是利润表方面的分析,与其有关的研究成果逐渐趋向于完善。由于苏宁易购在电商行业占据了极其重要的地位,所以利润表分析能够更清晰地披露苏宁易购在发展战略中所出现的问题。因此,利润表分析尤其重要,所以文本将从利润表的角度对苏宁易购进行分析。

关键词：利润表苏宁易购财务分析

Determination of hydroxyl radical in Fenton system

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2009年第10期20卷 1235-1240页

作者： Yan Fen Fang An ping deng Ying ping Huang Alan G. MacDiarmid Research Institute for Renewable Energy China Three Gorges University Yichang 443002 China

Under visible light illumination, 2,3-diaminophenazine （DAPN） was generated from the oxidation of o-phenylenediamine （OPDA） in Fe^3＋/H2O2 solution. Hydroxyl radical （＊OH） produced in this system was determined by directly measuring the concentration of DAPN. In comparison with the traditional methods, the determination is more accurate and simple.

关键词： Determination o-Phenylenediamine *OH Fenton