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Nano Research 2021年第11期14卷 4063-4072页

作者： Anchun Tang Chubin wan Xiaoyu hu Xin Ju School of Mathematics and Physics University of Science and Technology BeijingBeijing100083China

Ni/ZnO nano-sponges have been successfully synthesized through optimized annealing of Ni/Zn-based organic framework (Ni/Zn-MOF). The annealed MOF provides the stable carbon structure with 3D interconnection and prevents structural collapse during the charging and discharging process. The annealing causes the incorporation of intrinsic Ni^(3+) in the surface of NiO nanoparticles, providing more reaction active sites. The oxygen vacancies in ZnO and heterostructure interfaces between NiO and ZnO promote the charge transformation. Based on the aforementioned advantages, the Ni/ZnO nanocomposites exhibit excellent electrocatalytic performances for supercapacitors. The specific capacitance can reach to 807 F·g^(−1) at 1 A·g^(−1) in the studied electrodes. After 5,000 cycles at 10 A·g^(−1), the cyclic stability remains excellent at 86% of the initial capacitance. Moreover, the as-prepared asymmetric supercapacitor exhibits a high energy density of 30.6 W·h·kg^(−1) at power density of 398 W·kg^(−1). This study is expected to provide new insights into exploring the potential mechanism of catalyst action.

关键词： metal-organic frameworks ZnO-based nano-sponges surface vacancies supercapacitor electrochemical performance

higher-Twist Effect in Pion Parton Distribution

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Chinese Physics Letters 2021年第4期38卷 34-39页

作者： Lihong wan Jianhong Ruan Department of Physics East China Normal UniversityShanghai 200241China

A higher-twist modified parton evolution equation is used to evolve the initial valence quark distributions in pions,which are derived based on light-front quantization via BLFQ *** results are consistent with the valence quark distributions of the E615 experiment,and the pion structure function of the h1 *** structure function data highlight the necessity for a higher-twist modification in the small x *** with some other models are also given.

关键词： experiment. twist quark

Enhancement of sludge gravitational thickening with weak ultrasound

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Frontiers of Environmental Science & Engineering 2012年第5期6卷 753-760页

作者： Panyue ZhANG Tian wan Guangming ZhANG School of Environment Science and Engineering Hunan UniversityChangsha 410082China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China

Gravitational thickening is the prevailing method to reduce sludge volume but the process is slow and usually requires addition of polyelectrolyte（s）. This paper investigated the potential benefits of sonication on enhancing the sludge gravitational thickening with very low energy dose, so called ＂weak ultrasound＂. Results showed that weak sonication significantly changed the sludge settlability and the main mechanism was release of the loosely bounded extracellular polymeric substances. The changes in sludge behaviors by sonication were strongly influenced by power density and sonication duration. Lower sound frequency was slightly better than higher frequency. Weak sonication （〈 680 ***1 DS） improved the sludge gravitational thickening while high ultrasonic energy deteriorated the process. Considering both the sludge thickening efficiency and energy con- sumption the optimum conditions were 0.15 W. mL-l, 7 s, and 25 khz. Under such conditions, the energy dose was only 155 ***-1 DS, much lower than literature reports, and the sludge settling time was shortened from 24 h to 12 h. Weak sonication could substitute expensive poly- electrolyte coagulant for sludge thickening. Combination of weak sonication and polyelectrolyte could further reduce the settling time to 6 h. The final water content of the thickened sludge was not changed after sonication or polyelectrolyte addition.

关键词： activated sludge sonication settlability dryweight extracellular polymeric substances polyelectrolyte

A mass and energy estimation for the hydrogen utilization in the iron-making process

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Science China(Technological Sciences) 2011年第7期54卷 1655-1660页

作者： wan ho KIM Dong Joon MIN Department of Materials Science and Engineering YONSEI University

The possibility of using hydrogen to lower CO 2 emissions in the iron-making process was confirmed by the heat and mass balances in the blast furnace operation. The mass and heat balances for hydrogen utilization in the blast furnace were estimated by using the basic concept of RIST operating diagram. In this study, the RIST operating diagram was modified to be suitable for representing the operation with respect to hydrogen, where the RIST operating diagram is a graphical representation of heat and mass balance in blast furnace operation. RIST operating diagram was applied here to some individual parameters of interest such as h 2 injection in blast furnace process to reduce coke (carbon consumption). It was observed that the point W moved to the right in the RIST operating diagram under the condition of increasing hydrogen injection at tuyere, which originates from the contribution of gas composition (O/h 2 ) equilibrated with Fe/FeO at a certain temperature. Point P also moved downward due to heat requirement with respect to hydrogen utilization, by which the new RIST operating diagram for hydrogen utilization was able to be constructed. Under the condition of hydrogen injection, the expected overall carbon consumption in the blast furnace decreased due to the contribution of hydrogen.

关键词： hydrogen carbon consumption (CO2 emission) mass and heat balances RIST operating diagram blast furnace

Effects of nitrate concentration on biological hydrogen production by mixed cultures

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Frontiers of Environmental Science & Engineering 2009年第4期3卷 380-386页

作者： Bo wanG Wei wan Jianlong wanG Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

The effects of nitrate on fermentative hydrogen production and soluble metabolites from mixed cultures were investigated by varying nitrate concentrations from 0 to 10 g N/L at 35℃ with an initial ph of *** results showed that the substrate degradation rate,hydrogen production potential,hydrogen yield,and average hydrogen production rate initially increased with increasing nitrate concentrations from 0 to 0.1 g N/L,while they decreased with increasing nitrate concentrations from 0.1 to 10 g N/*** maximum hydrogen production potential of 305.0 mL,maximum hydrogen yield of 313.1 mL/g glucose,and maximum average hydrogen production rate of 13.3 mL/h were obtained at a nitrate concentration of 0.1 g N/*** soluble metabolites produced by the mixed cultures contained only ethanol and acetic acid(hAc)without propionic acid(hPr)and butyric acid(hBu).This study used the Modified Logistic model to describe the progress of cumulative hydrogen production in batch tests.A concise model was proposed to describe the effects of nitrate concentration on average hydrogen production rate.

关键词： nitrogen source biohydrogen fermentative hydrogen production quantitative kinetic model

Source-specific risk assessment for cadmium in wheat and maize:Towards an enrichment model for China

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Journal of Environmental Sciences 2023年第3期125卷 723-734页

作者： Zhong Zhuang Qiqi wang Siyu huang Andrea Giovanna NinoSavala Yanan wan huafen Li Andreas h.Schweiger Andreas Fangmeier Jürgen Franzaring Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation Key Laboratory of Plant-Soil Interactions of the Ministry of EducationCollege of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001China Institute of Landscape and Plant Ecology University of Hohenheim70599 StuttgartGermany

Cadmium (Cd) pollution of agricultural soil is of public concern due to its high potential toxicity and *** study aimed to reveal the risk of Cd accumulation in soil and wheat/maize systems,with a specific focus on the source-specific ecological risk,human health risk and Cd enrichment *** this we investigated more than 6100 paired soil and grain samples with 216 datasets including soil Cd contents,soil ph and grain Cd contents of 85 sites from *** results showed that mining activities,sewage irrigation,industrial activities and agricultural practices were the critical factors causing Cd accumulation in wheat and maize cultivated ***,mining activities contributed to a higher Cd accumulation risk in the southwest China and Middle Yellow River regions;sewage irrigation influenced the Cd accumulation in the North China *** addition,the investigated sites were classified into different categories by comparing their soil and grain Cd contents with the Chinese soil screening values and food safety values,*** enrichment models were developed to predict the Cd levels in wheat and maize *** results showed that the models exhibited a good performance for predicting the grain Cd contents among safe and warning sites of wheat (R2=0.61 and 0.72,respectively);while the well-fitted model for maize was prone to the overestimated sites (R2=0.77).This study will provide national viewpoints for the risk assessments and prediction of Cd accumulation in soil and wheat/maize systems.

关键词： Ecological risk Enrichment models Cadmium health risk assessment Pollution sources

SYNThESIS AND ChARACTERIZATION OF A NOVEL DOPANT (C3-ABSA) FOR SYNThESIZING TUBULAR POLYANILINE

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Chinese Journal of Polymer Science 2001年第1期19卷 65-70页

作者： hong-jin Qiu Mei-xiang wan Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

4-(3-(4-((4-Nitrophenyl)azo)phenyloxy)propyl)aminobenzene sulfonic acid (C3-ABSA) was synthesized by the reaction of 3-bromide-1-(4-((4-nitrophenyl)azo)phenyloxy)propane (B3) with sodium p-aminobenzene sulfonic acid (ABSA) and acidification with hydrochloric acid. The C3-ABSA was characterized by FTIR, h-1-NMR and second ion mass spectrum (SIMS). The molecular formula of dehydrated C3-ABSA was estimated to be ca. C21h20O6N4S by SIMS. Its decomposition temperature was measured by TGA to be ca. 232 degreesC. It was found that tubular polyaniline (PANI) with a conductivity of 1.1 S/cm at room temperature was successfully synthesized by in-situ doping polymerization in the presence of C3-ABSA as a dopant.

关键词： polyaniline microtubules sulfonic acid dopant conductivity

Advances in the Transition Metal-Free C—h Trifluoromethylation

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Chinese Journal of Chemistry 2022年第21期40卷 2582-2594页

作者： Demao Chen Jianwen Jiang Jie-Ping wan Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education College of Chemistry and Chemical EngineeringJiangxi Normal UniversityNanchangJiangxi 330022China.

Trifluoromethyl group is one of the most frequently available and promising functional groups in pharmaceutical,agrochemical as well as material *** synthetic methods for the synthesis of trifluoromethyl functionalized compounds by trifluoromethylation reactions occupies significant position in modern organic *** the other hand,as a typical tool of sustainable synthesis,transition metal-free synthesis possesses unique advantages in atom economy,easy product purification as well as excellent ***,transition metal-free trifluoromethylation reactions constitute the most important approaches for accessing trifluoromethylated ***,the advances in the transition metal-free C—h trifluoromethylation reactions are reviewed for the first *** to the updated state-of-art,both the catalytic reactions by conventional heating chemistry and the more sustainable photocatalysis are included,covering the trifluoromethylation reactions of C(sp^(3))–h bond,aromatic C(sp^(2))–h bond as well as the non-aromatic C(sp^(2))–h bond in different substrates over the last five years(2017—2021).

关键词： C-h bond Trifluoromethylation Transition metal-free Thermochemistry Photocatalysis

Using a novel adsorbent macrocyclic compound cucurbit[8]uril for Pb^(2+) removal from aqueous solution

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Journal of Environmental Sciences 2016年第12期28卷 3-12页

作者： Xuzhuo Sun Bo Li Dongjin wan Ning wang School of Chemical and Chemical Engineering Henan University of Technology

In this study, cucurbit[8]uril （CB[8]） was utilized as a kind of new adsorbent to remove Pb^2＋ ions from aqueous solution. With the solution ph increased from 2 to 6, the removal efficiency of adsorption increased from 55.6% to 74.5%correspondingly. The uptake of Pb^2＋ increased rapidly in the initial 30 min, and then the adsorption rate became slower. The Pseudo-second order model could be used to interpret the adsorption kinetics satisfactorily; and the rate determining step in Pb^2＋ adsorption onto CB[8] was the external mass transfer step. Equilibrium isotherm study reveals that the Langmuir model gave a better fitting result than Freundlich model. The maximum adsorption capacity calculated by the Langmuir model was 152.67 mg/g for 298 K, 149.70 mg/g for 313 K and 136.42 mg/g for 323 K, respectively. The adsorption is a spontaneous process of exothermic nature. The effect of the adsorbent dosage and the influences of solution ph and co-existing cations were also investigated. The CB[8] was synthesized and characterized by 1h NMR, IR, ESI-MS spectra, SEM-EDAX, Zeta-potential and BET-analysis. The adsorption mechanism was due to the coordination between CB[8] molecule and Pb^2＋ ions.

关键词： Cucurbituril Adsorption Kinetics Equilibrium Pb^2+

“I want to Feel That I Live in China”:Imaginaries and hospitality in International Students’(mis-)Encounters at a Top Chinese University

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Frontiers of Education in China 2020年第4期15卷 588-620页

作者： Fred DERVIN Anu hÄRKÖNEN Mei YUAN Ning ChEN wan ZhANG Faculty of Educational Sciences University of HelsinkiHelsinki 00014Finland Turku University of Applied Sciences Faculty of Educational SciencesUniversity of HelsinkiHelsinki 00014Finland School of Education Minzu University of ChinaBeijing 100081China School of Experimental Art Tianjin Academy of Fine ArtsTianjin 300141China

Research on international students’experiences abroad has tended to rely on models of adjustment,integration and/or acculturation to describe their(mis-)encounters with different kinds of people(e.g.,co-nationals,locals and other international students).This paper proposes to use the more fluid concepts of imaginaries and hospitality,leaving behind stages and phases of adaption and acculturation,and focusing on the influence of the Structure on their *** on a discursive pragmatic analysis of interview data with 20 international students at a top Chinese university,the authors review how the students describe the kind of hospitality experienced at this institution and the influence that it has on their(mis-)***,differentialist and essentialist imaginaries(static and fixed views of Chineseness)are often used to justify the lack of encounters and the“segregation”and somewhat“positive discrimination”that they ***,the paper shows that,amongst others,the institutional hospitality management for international students leads to closed contexts of encounters and feelings of *** the study serves as a case study and cannot be generalized to the many and varied experiences of international students in other universities in China,some recommendations are made to solve,at least in part,misconceptions about what interculturality and hospitality entail in the internationalization of higher education.

关键词： study abroad imaginaries interculturality hospitality international students culturalism