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Efficient nitrogen doped porous carbonaceous CO_(2) adsorbents based on lotus leaf

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Journal of Environmental Sciences 2021年第5期33卷 268-278页

作者： Qian Li Shenfang Liu Linlin Wang fangyuan chen Jiawei Shao Xin Hu Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Zhejiang Normal UniversityJinhua 321004China College of Engineering Zhejiang Normal UniversityJinhua 321004China

In this work, the waste biomass lotus leaf was converted into N-doped porous carbonaceous CO_(2) adsorbents. The synthesis process includes carbonization of lotus leaf, melamine post-treatment and KOH activation. For the resultant sorbents, high nitrogen content can be contained due to the melamine modification and advanced porous structure were formed by KOH etching. These samples were carefully characterized by different techniques and their CO_(2) adsorption properties were investigated in detail. These sorbents hold good CO_(2) adsorption abilities, up to 3.87 and 5.89 mmol/g at 25 and 0 °C under 1 bar, respectively. By thorough investigation, the combined interplay of N content and narrow microporous volume was found to be responsible for the CO_(2) uptake for this series of sorbents. Together with the high CO_(2) adsorption abilities, these carbons also display excellent reversibility, high CO_(2)/N 2 selectivity, applicable heat of adsorption, fast CO_(2) adsorption kinetics and good dynamic CO_(2) adsorption capacity. This study reveals a universal method of obtaining N-doped porous carbonaceous sorbents from leaves. The low cost of raw materials accompanied by easy synthesis procedure disclose the enormous potential of leaves-based carbons in CO_(2) capture as well as many other applications.

关键词： CO_(2)capture N-doped porous carbon Biomass materials Melamine KOH activation

Exsolutions of Diopside and Magnetite in Olivine from Mantle Dunite,Luobusa Ophiolite,Tibet,China

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Acta Geologica Sinica(English Edition) 2008年第2期82卷 377-384页

作者： REN Yufeng chen fangyuan YANG Jingsui GAO Yuanhong Key Laboratory of Continental Dynamics of the Ministry of Land and Resources Institute of Geology CAGS Beijing 100037

The exsolutious of diopside and magnetite occur as intergrowth and orient within olivine from the mantle dunite, Luobusa ophiolite, Tibet. The dunite is very fresh with a mineral assemblage of olivine （〉95%）＋ chromite （1%-4%）＋ diopside （〈1%）. Two types of olivine are found in thin sections： one （Fo = 94） is coarse-grained, elongated with development of kink bands, wavy extinction and irregular margins; and the other （Fo = 96） is fine-grained and poly-angied. Some of the olivine grains contain minor Ca, Cr and Ni. Besides the exsolutions in olivine, three micron-size inclusions are also discovered. Analyzed through energy dispersive system （EDS） with unitary analytical method, the average compositions of the inclusions are： Na20, 3.12%-3.84%; MgO, 19.51%-23.79%; Al2O3, 9.33%-11.31%; SiO2, 44.89%-46.29%; CaO, 11.46%-12.90%; Cr2O3, 0.74%-2.29%; FeO, 4.26%- 5.27%, which is quite similar to those of amphibole. Diopside is anhedral f＇dling between olivines, or as micro-inclusions oriented in olivines. Chromite appears euhedral distributed between olivines, sometimes with apparent compositional zone. From core to rim of the chromite, Fe content increases and Cr decreases; and A! and Mg drop greatly on the rim. There is always incomplete magnetite zone around the chromite. Compared with the nodular chromite in the same section, the euhedral chromite has higher Fe3O4 and lower MgCr2O4 and MgAI2O4 end member contents, which means it formed under higher oxygen fugacity environment. With a geothermometer estimation, the equilibrium crystalline temperature is 820℃-960℃ for olivine and nodular chromite, 630℃-770℃ for olivine and euhedral chromite, and 350℃-550℃ for olivine and exsoluted magnetite, showing that the exsolutions occurred late at low temperature. Thus we propose that previously depleted mantle harzburgite reacted with the melt containing Na, Al and Ca, and produced an olivine solid solution added with Na^＋, Al^3＋, Ca^2＋, Fe^3＋, Cr^3＋. With temperature decreasing, t

关键词： diopside magnetite exsolution olivine dunite ophiolite Luobusa Tibet

Barite in omphacite-hosted K-feldspar + quartz poly-crystalline aggregates from the Sulu eclogites and its implications

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Chinese Science Bulletin 2007年第21期52卷 2995-3001页

作者： ZENG LingSen LIU FuLai LIANG FengHua chen fangyuan Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

K-feldspar + quartz polycrystalline aggregates were found as sub-millimeter-size inclusions with a pseudomorph after coesite (?) in omphacites from a number of Sulu eclogites. In these aggregates, round or subhedral barites occur as tiny inclusions in either K-feldspar or quartz. Energy dispersive spectroscopy (EDS) analyses show that these barites have (1) 33.86%―41.12% SO3, 0%―34.65% SrO, and 24.12%―63.55% BaO, (2) seemingly negative linear correlations between SrO and BaO, indicating that they are ideal solid solutions of barite (BaSO4) and celestite (SrSO4), and (3) highly variable Sr/Ba molar ratios ranging from 0 to 2.1. Presence of barites in the Sulu eclogites not only indicates oxidation of the subducting continental crust, but also very limited and restricted fluids pre- sented during exhumation of the Sulu UHP eclogites.

关键词：重晶石集料变质作用石英石

Partial melting of deeply subducted continental crust and the formation of quartzofeldspathic polyphase inclusions in the Sulu UHP eclogites

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Chinese Science Bulletin 2009年第15期54卷 2580-2594页

作者： ZENG LingSen LIANG FengHua ASIMOW Paul chen fangyuan chen JJng Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA 91125 USA School of Physics Peking University Beijing 100871 China

Two types of quartzofeldspathic inclusions hosted by omphacite and garnet were identified in the Sulu UHP eclogites. The first consists of albite, quartz, and various amounts of K-feldspar. In contrast, the second consists predominantly of K-feldspar and quartz without any albite. The presence of quart-zofeldspathic inclusions within the UHP mafic eclogites indicates that partial melting occurred in deeply subducted continental crust via mica dehydration melting reactions at an early stage of rapid exhumation. Such a melting event generated hydrous Na-K-Al-Si melts. These melts infiltrated into the mafic eclogite and were captured by recrystallizing garnet or omphacite, which together followed by dehydration and crystallization to form feldspar-bearing polyphase inclusions. Formation of silicate melts within the deeply subducted continental slab not only provides an excellent medium to transport both mobile (LILE) and immobile (HFSE) elements over a large distance, but also induces effective changes in the physical properties of the UHP slab. This process could be a major factor that enhances rapid exhumation of a deeply subducted continental slab.

关键词：超高压榴辉岩大陆地壳深俯冲包裹体部分熔融多相体形快速折返

Improved Breakdown Strength in(Ba_(0.6)Sr_(0.4))_(0.85)Bi_(0.1)TiO_3 Ceramics with Addition of CaZrO_3 for Energy Storage Application

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Journal of Wuhan University of Technology(Materials Science) 2018年第3期33卷 545-551页

作者：汪小红 LI Zhenlin chen fangyuan 高俊雄 Lü Wenzhong School of Optical and Electronic Information Huazhong University of Science and Technology Key Lab of Functional Materials for Electronic Information(B) MOE Huazhong University of Science and Technology

（Ba（0.6） Sr（0.4））（0.85） Bi（0.1） TiO3 ceramics doped with x wt%CaZrO3（x= 0-10） were synthesized by solid-state reaction method. The effects of CaZrO3 amount on the dielectric properties and structure of（Ba（0.6）Sr（0.4））（0.85） Bi（0.1） TiO3 ceramics were investigated. X-ray diffraction results indicated a pure cubic perovskite structure for all samples and that the lattice parameter increased till x=5 and then slightly decreased. A homogenous microstructure was observed with the addition of CaZrO3. Dielectric measurements revealed a relaxor-like characteristic for all samples and that the diffusivity γ reached the maximum value of 1.78 at x=5. With the addition of CaZrO3, the dielectric constant dependence on electric field was weakened, insulation resistivity enhanced and dielectric breakdown strength improved obviously and reached 19.9 k V/mm at x=7.5. In virtue of low dielectric loss（tan d〈0.001 5）, moderate dielectric constant（er 〉1 500） and high breakdown strength（Eb 〉17.5 k V/mm）, the CaZrO3 doped（Ba（0.6）Sr（0.4））0.85 Bi（0.1） TiO3 ceramic is a potential candidate material for high power electric applications.

关键词： breakdown strength dielectric properties relaxor characteristic energy storage (Ba Sr) TiO3

Quantitative Analysis of the Effectiveness of Antigen-and Polymerase Chain Reaction-Based Combination Strategies for Containing COVID-19 Transmission in a Simulated Community

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Engineering 2023年第9期28卷 234-242页

作者： Qiangru Huang Yanxia Sun Mengmeng Jia Ting Zhang fangyuan chen Mingyue Jiang Qing Wang Luzhao Feng Weizhong Yang School of Population Medicine and Public Health Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China School of Arts and Sciences Beijing Institute of Fashion TechnologyBeijing 100105China

The number of coronavirus disease 2019(COVID-19)cases continues to surge,overwhelming healthcare systems and causing excess mortality in many *** of infectious populations remains a key strategy to contain the COVID-19 outbreak,delay the exponential spread of the disease,and flatten the epidemic *** the Omicron variant outbreak as a background,this study aimed to evaluate the effectiveness of testing strategies with different test combinations and frequencies,analyze the factors associated with testing effectiveness,and optimize testing strategies based on these influencing *** developed a stochastic,agent-based,discrete-time susceptible–latent–infectious–recovered model simulating a community to estimate the association between three levels of testing strategies and COVID-19 *** testing and its combination strategies were more efficient than polymerase chain reaction(PCR)-related *** testing also showed better performance in reducing the demand for hospital beds and intensive care unit *** delay in the turnaround time of test results had a more significant impact on the efficiency of the testing strategy compared to the detection limit of viral load and detection-related *** main advantage of antigen testing strategies is the short turnaround time,which is also a critical factor to be optimized to improve PCR *** modifying the turnaround time,the strategies with less frequent testing were comparable to daily *** choice of testing strategy requires consideration of containment goals,test efficacy,community prevalence,and economic *** study provides evidence for the selection and optimization of testing strategies in the post-pandemic era and provides guidance for optimizing healthcare resources.

关键词： COVID-19 Antigen testing PCR testing Testing strategies

In situ integration of efficient photocatalyst Cu1.8S/ZnxCd1-xS heterojunction derived from a metal-organic framework

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Chinese Chemical Letters 2020年第10期31卷 2795-2798页

作者： Dongpeng Zhang Pengfei Wang fangyuan chen Kelei Mu Yi Li Haitao Wang Zhijun Ren Sihui Zhan MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China School of Energy and Environmental Engineering Hebei University of TechnologyTianjin 300401China Department of Chemistry Tianjin UniversityTianjin 300072China

The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still ***,a novel strategy was developed to synthesize non-noble metal co-catalyst/solid solution heterojunctions using metal-organic frameworks(MOFs)as a precursor *** adjusting the content of MOFs,a series of Cu1.8S/ZnxCd1-xS heterojunctions were obtained,and the Cu1.8S(3.7%)/Zn0.35Cd0.65S sample exhibits a maximum hydrogen evolution rate of 14.27 mmol h^(-1) g^(-1) with an apparent quantum yield of 3.7%at 420 nm under visible-light ***,the relationship between the heterojunction and photocatalytic activity were investigated by detailed characterizations and density functional theory(DFT)calculations,which reveal that loading Cu1.8S can efficiently extend the light absorption,meanwhile,the electrons can efficiently transfer from Zn0.35Cd0.65S to Cu1.8S,thus resulting more photogenerated electrons participating in surface *** result can be valuable inspirations for the exploitation of advanced materials using rationally designed nanostructures for solar energy conversion.

关键词： Co-catalyst Cu1.8S/Zn0.35Cd0.65S Density functional theory(DFT) Charge separation and transfer

Gliadin nanoparticles stabilized by sodium carboxymethyl cellulose as carriers for improved dispersibility,stability and bacteriostatic activity of Natamycin

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Food Bioscience 2023年第3期53卷 887-895页

作者： Zhaojun Ban fangyuan chen Lingling Liu Shuang Zhang Lijun Wang Hongpeng Wang Luyin Wang Yi Zhu Zhejiang Provincial Key Laboratory of Chemical and Biological Processing Technology of Farm Products Zhejiang Provincial Collaborative Innovation Center of Agricultural Biological Resources Biochemical ManufacturingSchool of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhou310023China School of Environmental and Natural Resources Zhejiang University of Science and TechnologyHangzhou310023China Aksu Youneng Agricultural Technology Co. LtdAksu843001China

There is increasing interest in the development of Natamycin(Nata)containing ingredients appropriate as substitutes for chemical food preservatives,due to its safe and efficient antimycotic *** work reported that gliadin(Gli)could effectively perform as nano-vehicles to enhance Nata’s water dispersibility and ***-Gli nanoparticles(NPs)were prepared by adjusting the solution pH and anti-solvent method using the amphiphilicity of *** encapsulation rate of NPs could reach 85.5%,and the loading rate was 8.6%.Nata-Gli/CMC nanocomposite system was prepared using sodium carboxymethylcellulose(CMC)as an *** with the Nata-Gli NPs,the spherical structure of the particles with CMC addition is more apparent and more *** bacteriostatic properties of the Nata-Gli/CMC nanocomposite system against Penicillium expansum were tested in vitro and in *** results in vitro results confirmed that the application of Nata-Gli/CMC nanocomposite system improved the water dispersibility of natamycin and thus enhanced the bacteriostatic activity of *** results in vivo indicated that Nata-Gli/CMC nanocomposite system reduced the occurrence of rot and mildew in inoculated *** findings provide an effective strategy to provide a new idea for applying Nata and provide a reference for developing the post-harvest colloidal delivery system.

关键词： Natamycin Gliadin nanoparticles Antifungal Kumquat

A Scenario-Based Evaluation of COVID-19-Related Essential Clinical Resource Demands in China

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Engineering 2021年第7期7卷 948-957页

作者： Ting Zhang Qing Wang Zhiwei Leng Yuan Yang Jin Yang fangyuan chen Mengmeng Jia Xingxing Zhang Weiran Qi Yunshao Xu Siya chen Peixi Dai Libing Ma Luzhao Feng Weizhong Yang School of Population Medicine and Public Health Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Division of Infectious Diseases Chinese Center for Disease Control and PreventionBeijing 102206China Department of Respiratory and Critical Care Medicine The Affiliated Hospital of Guilin Medical UniversityGuilin 541001China

The coronavirus disease 2019(COVID-19)pandemic is a global crisis,and medical systems in many countries are overwhelmed with supply shortages and increasing demands to treat patients due to the surge in cases and severe *** study aimed to assess COVID-19-related essential clinical resource demands in China,based on different scenarios involving COVID-19 spreads and *** used a susceptible–exposed–infectious–hospitalized/isolated–removed(SEIHR)transmission dynamics model to estimate the number of COVID-19 infections and hospitalizations with corresponding essential healthcare resources *** found that,under strict non-pharmaceutical interventions(NPIs)or mass vaccination of the population,China would be able to contain community transmission and local outbreaks ***,under scenarios involving a low intensity of implemented NPIs and a small proportion of the population vaccinated,the use of a peacetime–wartime transition model would be needed for medical source stockpiles and preparations to ensure a normal functioning healthcare *** implementation of COVID-19 vaccines and NPIs in different periods can influence the transmission of COVID-19 and subsequently affect the demand for clinical diagnosis and *** increased proportion of asymptomatic infections in simulations will not reduce the demand for medical resources;however,attention must be paid to the increasing difficulty in containing COVID-19 transmission due to asymptomatic *** study provides evidence for emergency preparations and the adjustment of prevention and control strategies during the COVID-19 *** also provides guidance for essential healthcare investment and resource allocation.

关键词： COVID-19 Transmission dynamics model Clinical resource demands Vaccination