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How to Protect the Karst Aquifers?

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地学前缘 2009年第S1期16卷 32-33页

作者： Junbing Pu,Daoxian Yuan,Yongjun Jiang school of Geographical Sciences,southwest university,chongqing 400715,china.

The karst aquifers are the most important water resources in southwest china,where displays the most continuous bare karst around the world and hold about 100 million *** the rapid expansion of the urbanization,development of the industry and agriculture,the groundwater quality has been *** of the karst groundwater increases because of development of intensive *** of nitrate and sulphate increase notably as a result of the large amount of chemical fertilizer used in *** gas, waste water and waste residues produced in the processes of industrialization and urbanization cause groundwater acidification and an increase of pollutants such as nitrogen,phosphate,chloride,

关键词： karst aquifers groundwater quality -contamination protection measures

Single-atom Ni-N_(4) for enhanced electrochemical sensing

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Nano Research 2024年第8期17卷 7658-7664页

作者： Zhuhui Qin Bo Tang Guiru Zhang chongqing Zhu Kun Jiang Bowei Zhang Fu-Zhen Xuan Shanghai Key Laboratory of Intelligent Sensing and Detection Technology East China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety of Ministry of Education East China University of Science and TechnologyShanghai 200237China school of Mechanical and Power engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Theoretical and Computational Photochemistry Ministry of EducationCollege of ChemistryBeijing Normal UniversityBeijing 100875China Interdisciplinary Research Center School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Single-atom catalysts(SACs)attract widespread attention in heterogeneous catalysis due to their maximum atomic utilization efficiency and unique physical and chemical ***,their applications in chemical sensing keep huge potential but remain ***,a Ni-N_(4)-C SAC was synthesized for the trace detection of dopamine(DA)and uric acid(UA).The Ni-N_(4)-C SAC exhibited superior sensing performance compared to the Ni *** detection range for DA and UA were 0.05–75μM and 5–90μM with detection limits of 0.027 and 0.82μM,*** functional theory(DFT)computations indicate that Ni-N_(4)-C has a lower reaction barrier during electrochemical process,indicating that the atomic Ni sites possess higher intrinsic activity than Ni ***,DA and UA show strong potential dependency on the Ni-N_(4)-C catalyst,indicating its applicability for their concurrent *** work extends the application of SACs in chemical sensing.

关键词： single-atom catalysts chemical sensing dopamine uric acid

A contribution to the study of the modified Marschalk reaction:Hydroxymethylation of 6,8-O-dimethyl emodin

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Chinese chemical Letters 2010年第5期21卷 568-571页

作者： Hai Shan Jin,Li Ming Zhao school of chemistry and chemical engineering,Xuzhou Normal university,Xuzhou 221116,china school of chemistry and chemical engineering Xuzhou Normal University Xuzhou 221116 China

Hydroxymethylation of 6,8-O-dimethyl emodin was easily achieved in good yields by the modified Marschalk *** influence of the amount of solvent,base and formaldehyde toward the hydroxymethylation was *** results showed that a relatively dilute reaction solution facilitated the generation of the desired 2-hydromethyl product,while the thick reaction solution benefited the generation of the methylated quinizarins.

关键词： Marschalk reaction Hydroxymethylation Emodin Antitumor activity

Development of Multi-Wavelength Spectral-Correction Method

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Chinese chemical Letters 2000年第10期11卷 893-894页

作者： Hong Wen GAO (school of chemistry and chemical engineering, Anhui university, Hefei 230039) Sch. of Chem. and Chem. engineering Anhui University Hefei 230039 China

This investigation developed a new method for determining metal complex's property containing the stepwise real absorptivity(epsilon) and stability constant (K-m). The correction equation of the multi-wavelength spectral absorption was established for the simultaneous determination of various complexes to give high accuracy for trace analysis. This method was more acceptable in theory and simpler in operation than the classical methods.

关键词： simultaneous determination multi-wavelength spectral-correction complex property

Study of technology on MnSO4 preparation from highferrous manganese spar

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西南师范大学学报(自然科学版) 1999年第5期 566-570页

作者： Hu Debin 1,Li Nianbing 2, Zhang Shengtao 1, Han Lianyi 1 1 College of chemistry and chemical engineering,chongqing university,400044 2 College of chemistry and chemical engineering,southwest china Normal university,400715

Preparation of MnSO 4 from high ferrous manganese spar is studied by *** in traditional ways,such as undesirable increasing of solution viscosity and difficulty in neutralization, are solved *** recovery ratio can be ... 详细信息

关键词： high ferrous manganese spar manganese recovery ratio filtration time

Optical applications of quantum dots in biological system

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Science china chemistry 2011年第8期54卷 1177-1184页

作者： WANG Wei & ZHU Jun-Jie State Key Laboratory of Analytical chemistry for Life Science school of chemistry and chemical engineering, Nanjing university, Nanjing 210093, china State Key Laboratory of Analytical chemistry for Life Science school of chemistry and chemical engineering Nanjing University Nanjing China

This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed.

关键词： quantum dots optical application biological system

Preparation of new sunscreen materials Ce_(1-x)Zn_xO_(2-x) via solid-state reaction at room temperature and study on their properties

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Rare Metals 2010年第2期29卷 149-153页

作者： WU Wenwei, LI Shushu, LIAO Sen, XIANG Feng, and WU Xuehang school of chemistry and chemical engineering, Guangxi university, Nanning 530004, china school of chemistry and chemical engineering Guangxi University Nanning China

Superfine cerium-zinc oxides Ce1-xZnxO2-x with x = 0, 0.1, 0.3, 0.5, and 1.0 were obtained by grinding Ce（SO4）2·4H2O, ZnSO4·7H2O and NH4HCO3 under the condition of surfactant PEG-400 being present at room temperature, washing the mixture with water to remove soluble inorganic salts, drying at 80°C, and *** precursor and its calcined samples were characterized using thermogravimetry and differential thermal analyses（TG/DTA）, UV-vis absorption spectroscopy, X-ray powder diffraction（XRD）, and scanning electron microscopy（SEM）.The results showed that superfine Ce1-xZnxO2-x behaved as an excellent UV-shielding *** ZnO-doped CeO2 can facilitate the formation of crystalline state *** catalytic ability of products used in air oxidation of castor oil was *** results showed that the catalytic abilities of products decreased with increasing zinc amount.

关键词： cerium oxide zinc oxide solid-state reaction UV absorbency catalytic properties

One-dimensional metal phosphonates based on 6-phosphononicotinic acid:A structural and magnetic study

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Science china chemistry 2010年第10期53卷 2112-2117页

作者： WANG PengFei, DUAN Yan & ZHENG LiMin State Key Laboratory of Coordination chemistry Coordination chemistry Institute, school of chemistry and chemical engineering, Nanjing university, Nanjing 210093, china State Key Laboratory of Coordination chemistry Coordination chemistry Institute School of Chemistry and Chemical Engineering Nanjing University Nanjing China

The reactions of 6-phosphononicotinic acid (pnaH3) and metal salts result in three new compounds, namely, M(pnaH)-(H2O)3·H2O [M = Co(Ⅱ) (1), Ni(Ⅱ) (2), Zn(Ⅱ) (3)]. These compounds are isostructural and contain 21 helical chains made up of corner-sharing {MO5N} octahedra and {PO3C} tetrahedra. The chains are further connected by extensive hydrogen bonds to form a three-dimensional supramolecular structure. Magnetic studies reveal that dominant antiferromagnetic interactions are mediated in both 1 and 2. Interestingly the dehydrated compound 1 shows metamagnetic behavior at low temperature.

关键词： carboxylate-phosphonate coordination polymer magnetic property metamagnetism

MORPHOLOGY AND PROPERTIES OF LINEAR LOW-DENSITY POLYETHYLENE HIGHLY LOADED WITH ALUMINUM HYDROXIDE

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Chinese Journal of Polymer Science 2002年第3期20卷 253-259页

作者： Gen-lin Wang Ping-kai Jiang Zi-kang Zhu Jie Yin school of chemistry and chemical engineering Shanghai Jiaotong university Shanghai 200240 china school of chemistry and chemical engineering Shanghai Jiaotong University 上海 200240

An experimental study was carried out to investigate the effects of isopropoxy tri(dioctyl pyrophosphoryl) titanate coupling agent on the mechanical performance, rheological property and microstructures of polyethylene highly loaded with aluminum hydroxide (Al(OH)(3)) composite, It was found that the addition of coupling agent results in reduced tensile strength and increased percentage elongation of the filled systems. Silane crosslinkable polyethylene substituting for polyethylene as matrix improves the tensile strength of the composite, while the percentage elongation of the composite still remains at a desired level. Melt viscosity of the composite will be improved by addition of titanate coupling agent. Microstructures of the composites were also studied by means of the scanning electron microscopy (SEM) technique. SEM micrographs reveal that finer dispersion of Al(OH)(3) will be obtained upon treatment of titanate and a transition from brittle to tough fracture takes place before and after silane crosslinking structure is introduced into polyethylene highly filled with Al(OH)(3) composite.

关键词： polyethylene aluminum hydroxide organic titanate silane crosslink