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Arsenite oxidation by three types of manganese oxides

Journal of Environmental Sciences 2006年第2期18卷 292-298页

作者： feng Xiong-han ZU Yan-qun tan wen-feng LIU Fan College of Resources and Environment Huazhong Agricultural University Wuhan 430070 China College of Resources and Environment Yunnan Agricultural University Kunming 650201 China

Oxidation of As（Ⅲ） by three types of manganese oxides and the effects ofpH, ion strength and tartaric acid on the oxidation were investigated by means of chemical analysis, equilibrium redox, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Three synthesized Mn oxide minerals, bimessite, cryptomelane, and hausmannite, which widely occur in soil and sediments, could actively oxidize As（Ⅲ） to As（Ⅴ）. However, their ability in As（Ⅲ）-oxidation varied greatly depending on their structure, composition and surface properties. Tunnel structured cryptomelane exhibited the highest ability of As （Ⅲ） oxidation, followed by the layer structured birnessite and the lower oxide hausmannite. The maximum amount of As （Ⅴ） produced by the oxidation was in the order （mmol/kg） of cryptomelane （824.2）〉 bimessite （480.4）〉 hausmannite （117.9）, As pH increased from the very low value（pH 2.5）, the amount of As（Ⅲ） oxidized by the tested Mn oxides was firstly decreased, then negatively peaked in pH 3.0 6.5, and eventually increased remarkably. Oxidation of As（Ⅲ） by the Mn oxides had a buffering effects on the pH variation in the solution. It is proposed that the oxidative reaction processes between As （Ⅲ） and biruessite（or cryptomelane） are as follows：（1） at lower pH condition：（MnO2）x＋ H3AsO3 ＋ 0.5H^＋=0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋Mn〉^2＋（MnO2）x-1 ＋ H2O; （2） at higher pH condition：（MnO2）x ＋ H3AsO3 = 0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋ 1.5H^＋＋（MnO2）x-1. MnO. With increase of ion strength, the As（Ⅲ） oxidized by bimessite and cryptomelane decreased and was negatively correlated with ion strength. However, ion strength had little influence on As （Ⅲ） oxidation by the hausmarmite. The presence of tartaric acid promoted oxidation of As（Ⅲ） by birnessite. As for cryptomelane and hansmannite, the same effect was observed when the concentration of tartaric acid was below 4 mmol/L, otherwise the oxidized As（Ⅲ） decreased. These findings are of great significance in improving our understanding

关键词： oxidation of As(Ⅲ) As(Ⅴ) Mn oxides pH ion strength tartaric acid

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Geochemical Characteristics of Trace Elements in Argillans of Alfisols in Central China

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Pedosphere 2015年第3期25卷 415-427页

作者： HUANG Li LIU Fan tan wen-feng WANG Ming-Kuang Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) Ministry of AgricultureHuazhong Agricultural University Department of Agricultural Chemistry Taiwan University

The relationships between the basic properties and trace elements in soil argillans and corresponding matrix soils were studied by sampling from the B horizons of 26 Alfisols in croplands of the subtropical area in Central China. The soil elements(K, Na, Ca,Mg, Mn, Co, Cu, Cr, Cd, Li, Mo, Ni, Pb, Ti, V, and Zn) were extracted by acid digestion and their contents were measured using inductively coupled plasma optical emission spectrometry(ICP-OES). The mean contents of clay and organic matter in the argillans were approximately 1.1 and 1.3 times greater than those in the matrix soils, respectively. The p H values and the contents of P2O5 and bases(K2O, Na2 O, Ca O, and Mg O) in the argillans were higher than those in the corresponding matrix soils. Cu, Cd, Ti, and V were enriched in the argillans. Correlation coefficients and factor analyses showed that Co, Cu, Li, and Zn were bound with phyllosilicates and manganese oxides(Mn-oxides) in the argillans. Cr and Pb were mainly associated with iron oxides(Fe-oxides), while Ni was bound with Mn-oxides. Cd, Ti, and V were chiefly associated with phyllosilicates, but Cr and Mo were rarely enriched in the *** contrast, in the matrix soils, Co and Zn were associated with organic matter and Fe-oxides, Cr existed in phyllosilicates, and Mo was bound to Fe-oxides. Cd, Ti, and V were associated with organic matter. The results of this study suggest that clays, organic matter, and minerals in the argillans dominate the illuviation of trace elements in Alfisols. Argillans might be the active interfaces of elemental exchange and nutrient supply in cropland soils in Central China.

关键词： clay cutan organic matter phyllosilicates soil element

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Elemental Composition and Geochemical Characteristics of Iron-Manganese Nodules in Main Soils of China

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Pedosphere 2006年第1期16卷 72-81页

作者： tan wen-feng LIU Fan LI Yong-Hua HU Hong-Qing HUANG Qiao-Yun College of Resources and Environment Huazhong Agricultural University Wuhan 430070 （China）. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101（China）

Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of iron-manganese nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-manganese nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-manganese nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-manganese nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-manganese nodules were divided into four groups: 1) Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-manganese nodules.

关键词： elemental composition geochemical characteristics iron-manganese nodule soil

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Effect of Cobalt-Doped Framework on Formation of Todorokite from Layered Manganese Oxides with Mg^(2+)/Co^(2+) Ions as Template

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Pedosphere 2011年第6期21卷 730-737页

作者： CUI Hao-Jie LIU Fan tan wen-feng feng Xiong-Han Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 （China） Key Laboratory of Subtropical Agricultural Resources and Environment Ministry of Agriculture Huazhong Agricultural University Wuhan 430070 （China）

Cobalt （Co） exists in significant quantities in naturally occurring manganese （Mn） oxides and alters the growth of Mn oxide crystals. Four-layered Mn oxides, Na-buserite （Na-bus） and three Co-doped Na-buserite samples prepared from oxidation of Mn（OH）2 with 5%, 10%, and 20% Co/（Mn ＋ Co） molar ratios （5Co-Na-bus, 10Co-Na-bus, and 20Co-Na-bus）, were used to prepare todorokite, a common Mn oxide on the Earth＇s surface, using Mg2＋/Co2＋ ions as a template. The results showed that todorokites could be obtained by reflux treatment of Mg2＋-exchanged non-doped Na-buserite and three Co-doped Na-buserites at atmospheric pressure. However, the formation of todorokites was prohibited by reflux treatment of Co2＋-exchanged Na-bus, 5Co-Na-bus, and 10Co-Na-bus samples. Instead, todorokite was obtained by the reflux treatment of Co2＋-exchanged 20Co-Na-bus samples under atmospheric pressure. X-ray photoelectron spectroscopy analysis showed that doped Co existed as Co3＋ in the MnOs layers of doped Na-buserites. The amount of substituted Co3＋ in the MnO6 layers may play a key role in the conversion of buserite to todorokite using Co2＋ ions as a template.

关键词： Mn oxide Na-buserite reflux treatment transformation tunnel structure

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Ecological functions of biochar

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Journal of Integrative Agriculture 2019年第7期18卷 1473-1473页

作者： tan wen-feng LIN Qi-mei Guest Editor College of Resources and Environment Huazhong Agricultural University Wuhan 430070 P.R.China Guest Editor College of Resource and Environment China Agricultural University Beijing 100193 P.R.China

Biochar has been widely applied as a soil amendment in many parts of the world,which can enhance soil organic carbon (SOC) sequestration and nutrient availability beyond the fertilizer *** in poly-condensed aromatic C... 详细信息

关键词： nutrient availability Biocharcoal Soil improver

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李鸿章签订《中俄密约》中的两个问题

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历史档案 1999年第4期12卷 119-122,127页

作者：谭文凤

《中俄密约》是李鸿章与俄国外交大臣罗拔诺甫、财政大臣维特于１８９６年６月３日在莫斯科签订的，又称中俄《御敌互相援助条约》。沙俄通过该条约掠取了中国东北的路权，加重了中华民族危机。笔者认为李鸿章作为中俄谈判的全权代表、... 详细信息

《中俄密约》是李鸿章与俄国外交大臣罗拔诺甫、财政大臣维特于１８９６年６月３日在莫斯科签订的，又称中俄《御敌互相援助条约》。沙俄通过该条约掠取了中国东北的路权，加重了中华民族危机。笔者认为李鸿章作为中俄谈判的全权代表、条约的签订者，有着不可推卸的责任。但我?（共5页)

关键词：李鸿章《中俄密约》总理衙门《议定书》俄国清政府张之洞外交政策翁同和《马关条约》

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Effect of Shock Absorbers’ Deformation on RLG’s Bias Temperature Modeling

Effect of Shock Absorbers’ Deformation on RLG’s Bias Tempe...

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第26届中国控制与决策会议

作者： tan wen-feng HU Chun-sheng WANG Xing-shu College of Optoelectronic Science and Engineering National University of Defense Technology

ISBN: (纸本)9781479937097

The deformation of shock absorbers has a great impact on gyro bias output during the system-level temperature modeling of gyro bias. In this paper, two ways of shock absorbers’ effect on gyro bias output are proposed: change of the Earth’s rotation component and slow movement of IMU apperceived by gyro. This paper analyzes the change of the Earth’s rotation component caused by the change of gyro’s sensitive axis. The effect of IMU’s slow movement is estimated. A method on how to place the gyro to weaken the impact of shock absorbers’ deformation is proposed. The effect of shock absorbers’ deformation on bias’ temperature model and accuracy of temperature compensation is analyzed through simulation.

关键词： shock absorbers bias temperature modeling

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Experimental demonstration of 220-GHz terahertz signals wireless transmission over 4.6 km

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Science China(Information Sciences) 2025年第1期68卷 386-388页

作者： Yi WEI Jianjun YU Mingxu WANG Xiongwei YANG Qiutong ZHANG Jingwen tan Bing ZHANG Ying WU Yang HAN Peng TIAN wen ZHOU Kaihui WANG feng ZHAO State Key Laboratory of ASIC and System Key Laboratory for Information Science of Electromagnetic Waves (MoE)School of Information Science and Technology Fudan University School of Electronic Engineering Xi'an University of Posts and Telecommunications

The advancement of terahertz (THz) communication technology drives the evolution of wireless communication systems,offering novel pathways and technical means for the development of future 6G communication *** wireless communication systems are often constrained by bandwidth limitations of electronic devices in high frequency ***,THz communication technology leverages the characteristics of electromagnetic waves to transcend these limitations,enabling communication athigher frequencies and wider bandwidths.

关键词：

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不同锰氧化度水钠锰矿的XPS研究

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中南大学学报（自然科学版） 2012年第2期43卷 776-782页

作者：赵巍刘凡冯雄汉谭文峰西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室陕西杨凌712100 中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室陕西杨凌712100 华中农业大学农业部亚热带农业资源与环境重点开放实验室湖北武汉430070

为了了解水钠锰矿八面体空位的具体分布状况以及表面化学性质,采用X线光电子能谱技术（XPS）对不同锰氧化度水钠锰矿表面Mn与O元素的化学状态进行研究;探讨水钠锰矿结构中空位的分布状况,并建立结构模型。研究结果表明：在高真空测试环... 详细信息

为了了解水钠锰矿八面体空位的具体分布状况以及表面化学性质,采用X线光电子能谱技术（XPS）对不同锰氧化度水钠锰矿表面Mn与O元素的化学状态进行研究;探讨水钠锰矿结构中空位的分布状况,并建立结构模型。研究结果表明：在高真空测试环境下,在不同锰氧化度水钠锰矿结构中,Mn存在饱和配位和不饱和配位2种化学状态,其含量（摩尔数分数,下同）分别为83.79%-91.69%和8.31%-17.21%;对于锰氧化度较高的水钠锰矿,不饱和配位Mn的含量较小;O以晶格氧、羟基氧和水分子中氧3种化学状态存在,其含量分别为50.44%-65.05%,24.90%-39.27%和8.07%-12.63%;对于锰氧化度较高的水钠锰矿,结构中羟基氧的含量较大;当水钠锰矿沿（110）方向上含Mn^3＋的MnO6八面体链中Mn^3＋含量增大时,结构中空位含量相应减少。

关键词：锰氧化度水钠锰矿 X线光电子能谱空位分布结构模型

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Catalytic production of high-energy-density spiro polycyclic jet fuel with biomass derivatives

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Journal of Energy Chemistry 2025年第2期101卷 760-768页

作者： wen-Jing Zhang Yan-Cheng Hu Yan-Hong tan Jia Li Ning Li Jing-Pei Cao School of Chemical Engineering and Technology China University of Mining and Technology CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

High-energy-density（HED） fuel（*** used JP-10 and RJ-4）,featuring compact 3D polycyclic structure with high strain,is of critical importance for volume-limited military aircraft,since their high density and combustion heat can provide more propulsion *** reduce the reliance on petroleum source,it is highly desirable to develop renewable alternatives for the production of strained polycyclic HED fuel,but which remains a big challenge because of the inaccessibility caused by the high strain,We herein demonstrate a three-step catalytic route towards highly strained C17and C18spirofuel with biomass *** process includes catalytic aldol condensation of renewable cyclohexanone/cyclopentanone with benzaldehyde,catalytic spiro Diels-Alder（D-A） reaction of aldol adduct with isoprene,and catalytic *** key spiro D-A reaction is enabled by the catalysis of heterogeneous Lewis acidic ionic *** chloroaluminate IL,formed by benign urea and AICl3,exhibits good catalytic performance and reusability for this *** eventual hydrodeoxygenation（HDO）over Pd/C and H-Y produces strained tricyclic spirofuel with density>0.93 g/mL,combustion heat>41 MJ/L and freezing point <-40℃,which are better than the properties of tactical fuel ***,it is anticipated that the as-prepared renewable fuels have the potential to replace traditional petroleum-derived HED fuels.

关键词： Biomass derivatives Cycloaddition High-energy-density Lewis acidic ionic liquid Spiro polycyclic fuel

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