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Silvery fullerene in Ag102 nanosaucer

National Science Review 2024年第07期 158-167页

作者： Zhi Wang Yuchen Wang Chengkai Zhang Yan-Jie Zhu Ke-Peng Song Christine M.Aikens Chen-Ho Tung Di Sun School of Chemistry and Chemical Engineering Shandong University Department of Chemistry Kansas State University

Despite the discovery of a series of fullerenes and a handful of noncarbon clusters with the typical topology of Ih-C60, the smallest fullerene with a large degree of curvature, C20, and its other-element counterparts are difficult to isolate experimentally. In coinage metal nanoclusters（NCs）, the first all-gold fullerene, Au32, was discovered after a long-lasting pursuit, but the isolation of similar silvery fullerene structures is still challenging. Herein, we report a flying saucer-shaped 102-nuclei silver NC（Ag102） with a silvery fullerene kernel of Ag32, which is embraced by a robust cyclic anionic passivation layer of（KPO4）10. This Ag32kernel can be viewed as a non-centered icosahedron Ag12encaged into a dodecahedron Ag20, forming the silvery fullerene of Ag12@Ag20. The anionic layer（KPO4）10is located at the interlayer between the Ag32kernel and Ag70shell, passivating the Ag32silvery fullerene and templating the Ag70shell. The ~tBuPhS-and CF3COO-ligands on the silver shell show a regioselective arrangement with the 60 ~tBuPhS-ligands as expanders covering the upper and lower of the flying saucer and 10 CF3COO-as terminators neatly encircling the edges of the structure. In addition, Ag102 shows excellent photothermal conversion efficiency（η） from the visible to near-infrared region（η = 67.1% ± 0.9% at 450 nm, 60.9% ± 0.9% at 660 nm and 50.2% ± 0.5% at 808 nm）, rendering it a promising material for photothermal converters and potential application in remote laser ignition. This work not only captures silver kernels with the topology of the smallest fullerene C20, but also provides a pathway for incorporating alkali metal（M） into coinage metal NCs via M-oxoanions.

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CONSTRUCTING UNIFORM DESIGNS WITH TWO- OR THREE-LEVEL

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Acta Mathematica Scientia 2006年第3期26卷 451-459页

作者：覃红张尚立方开泰 Department of Mathematics Central china Normal University Wuhan 430079China Department of MathematicsHong Kong Baptist UniversityHong KongChina Department of Mathematics Beijing Jiaotong University Beijing 100044China Department of Mathematics Hong Kong Baptist University Hong KongChina

When the number of runs is large, to search for uniform designs in the sense of low-discrepancy is an NP hard problem. The number of runs of most of the available uniform designs is small （≤50）. In this article, the authors employ a kind of the so-called Hamming distance method to construct uniform designs with two- or three-level such that some resulting uniform designs have a large number of runs. Several infinite classes for the existence of uniform designs with the same Hamming distances between any distinct rows are also obtained simultaneously. Two measures of uniformity, the centered L2-discrepancy （CD, for short） and wrap-around L2-discrepancy （WD, for short）, are employed.

关键词： Discrepancy Hadamard matrix Hamming distance uniform design

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Perovskite LaFeO_3 supported bi-metal catalyst for syngas methanation

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Journal of Natural Gas Chemistry 2012年第6期21卷 745-752页

作者： Hong Wang Yuzhen Fang Yuan Liu Xue Bai School of Chemical Engineering Inner Mongolia University of TechnologyHohhot 010062Inner MongoliaChina Tianjin Key Laboratory of Applied Catalysis Science and Engineering Department of Catalysis Science and TechnologySchool of Chemical EngineeringTianjin UniversityTianjin 300072China

LaFeO3 perovskite supported Ni and Ni-Fe catalysts were prepared and applied to methanation reaction of syngas. Two preparation methods were employed. One was one-step citrate complexing method, and the other was a two step method using citrate complexing method to produce LaFeO3 and followed by loading nickel oxide on it with impregnation. The structure evolution of the sample as prepared was investigated by XRD, TPR and TEM techniques. For the former, the chemical composites of the calcined sample are NiO-Fe2O3/LaFe1-xNixO3. After reduction and reaction of CO methanation, its composites convert to Fe-Ni@Ni/LaFeO3-La2O2CO3, in which Fe-Ni@Ni is metal particles in nano-size composed of nickel core and Fe-Ni alloy shell. For the latter, the chemical composites of the calcined sample are NiO/LaFeO3; and after reduction and reaction of CO methanation, its chemical composites change to Ni/LaFeO3. Ni/LaFeO3 catalyst is a little more active, while Fe-Ni@Ni/LaFeO3-La2O2CO3 is much more stable and shows very good resistance to carbon deposition. In this work it is aimed to show that the structure and composites of the catalysts can be tailored using perovskite-type oxide as precursor with different preparing method or preparing condition. Therefore, it is a promising route to prepare supported bi-metal catalysts in nano-size for a lot of metals with desired catalytic performances.

关键词： perovskite bi-metal nickel iron syngas methanation

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Lipid Biomarkers and Their Stable Carbon Isotopes in Ancient Seep Carbonates from SW Taiwan, china

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Acta Geologica Sinica(English Edition) 2019年第1期93卷 167-174页

作者： GUAN Hongxiang XU Lanfang WANG Qinxian CHEN Duofu WU Nengyou MAO Shengyi Key Laboratory of Gas Hydrate Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology University of Chinese Academy of Sciences Shanghai Engineering Research Center of Hadal Science and Technology College of Marine Sciences Shanghai Ocean University

Four massive brecciated, chimney-like, and slender pipe network carbonate samples(JA-4, JA-5, JX-8 and BG-12) were collected from southwestern Taiwan, which were suggested to have formed as a result of anaerobic oxidization of methane(AOM). Considering that the environmental conditions of the carbonates precipitation and the sources of carbon and organic matter need to be further declared, molecular fossils and compound-specific carbon isotopic investigations of the carbonates were conducted in this study. According to lipid biomarkers of 2,6,10,15,19-pentamethyleicosane(PMI) and squalane diagnostic to methanotrophic archaea, as well as the extremely low δ^(13)C values(as low as -1^(13).4‰) detected in samples JA-4, JA-5 and JX-8, these carbonates were revealed to be a result of AOM. Based on the varied δ^(13)C values of characteristic archaea biomarkers in specific samples, biogenic methane was proposed to be responsible for the formation of samples JA-4 and JA-5, whereas a mixed carbon source of ^(13)C-depleted methane and ^(13)C-enriched residual CO_2 from methanogenesis was suggested for the carbonate of JX-8 due to the co-occurrence of a highly positive δ^(13) C_(carb) value(+8‰) and a moderate ^(13)C depletion of PMI. The low content of AOM-related biomarkers and the absence of indicators for ANME-2 suggested that these carbonates were formed in weak seep settings. By comparison, no typical lipid biomarkers for methanotrophic archaea was detected in carbonate BG-12. The short-chain and long-chain n-alkanes accounted for 30% and 45% of all hydrocarbons, respectively, with a CPI value of 1.2, suggesting that the n-alkanes were derived from both marine organisms and terrestrial inputs. A low thermal maturity could be revealed by the incomplete equilibrium value of the C^(31)αβ 22S/(22S+22R) ratio(0.5), and the carbonate BG-12 was probably deposited in a suboxic condition indicated by a value of Pr/Ph ratio(2.5).

关键词： methane seeps lipid biomarkers anaerobic oxidation of methane weak seep settings

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Risk estimation and prediction of the transmission of coronavirus disease-2019(COVID-19)in the mainland of china excluding Hubei province

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Infectious Diseases of Poverty 2020年第4期9卷 146-147页

作者： Hui Wan Jing-An Cui Guo-Jing Yang Jiangsu Key Lab for NSLSCS School of Mathematical SciencesNanjing Normal UniversityNanjingChina Department of Mathematics School of ScienceBeijing University of Civil Engineering and ArchitectureBeijingChina Hainan Medical University Haikou571199China Swiss Tropical and Public Health Institute Socinstrasse 57BaselCH-4002Switzerland University of Basel BaselSwitzerland

Background In December 2019,an outbreak of coronavirus disease(later named as COVID-19)was identified in Wuhan,china and,later on,detected in other parts of *** aim is to evaluate the effectiveness of the evolution of interventions and self-protection measures,estimate the risk of partial lifting control measures and predict the epidemic trend of the virus in the mainland of china excluding Hubei province based on the published data and a novel mathematical *** A novel COVID-19 transmission dynamic model incorporating the intervention measures implemented in china is ***-19 daily data of the mainland of china excluding Hubei province,including the cumulative confirmed cases,the cumulative deaths,newly confirmed cases and the cumulative recovered cases between 20 January and 3 March 2020,were archived from the National Health Commission of china(NHCC).We parameterize the model by using the Markov Chain Monte Carlo(MCMC)method and estimate the control reproduction number(Rc),as well as the effective daily reproduction ratio-Re(t),of the disease transmission in the mainland of china excluding Hubei *** The estimation outcomes indicate that Rc is 3.36(95%CI:3.20–3.64)and Re(t)has dropped below 1 since 31 January 2020,which implies that the containment strategies implemented by the Chinese government in the mainland of china are indeed effective and magnificently suppressed COVID-19 ***,our results show that relieving personal protection too early may lead to a prolonged disease transmission period and more people would be infected,and may even cause a second wave of epidemic or *** calculating the effective reproduction ratio,we prove that the contact rate should be kept at least less than 30%of the normal level by April,*** To ensure the pandemic ending rapidly,it is necessary to maintain the current integrated restrict interventions and self-protection measures,including travel restriction

关键词： COVID-19 Risk estimation and prediction Intervention measure Contact tracing Control reproduction number Effective daily reproduction ratio Mathematical model

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Co/CeO_2 for ethanol steam reforming:effect of ceria morphology

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Journal of Rare Earths 2013年第6期31卷 565-571页

作者：王红张丽娟李淼刘源白雪 School of Chemical Engineering Inner Mongolia University of Technology Tianjin Key Laboratory of Applied Catalysis Science and Engineering Department of Catalysis Science and TechnologySchool of Chemical EngineeringTianjin University

Nanorods （NR） and nanoparticles （NP） of ceria were prepared by hydrothermal synthesis method and used as catalyst support to load cobalt for steam reforming of ethanol （SRE）. The catalysts were characterized by using temperature programmed reduction, X-ray diffraction, transmission electron microscopy and thermal analysis techniques. CeO2 NP had relatively smaller particle size and larger surface area, and CeO2 NR could form more oxygen vacancies. For SRE reaction, Co/CeO2 NP was more active and exhibited a little better anti-sintering ability, while Co/CeO2 NR showed obviously better anti-carbon deposition ability. The larger surface area and higher dispersion of cobalt oxide resulted in the higher activity for Co/CeO2 NP catalyst. Meanwhile, the stronger interaction between cobalt species and ceria was attributed to the better anti-sintering ability for Co/CeO2 NP. The improvement of the anti-carbon deposition for Co/CeO2 NR was owing to the generation of oxygen vacancies from the ceria nanorods.

关键词： morphology ceria cobalt ethanol steam reforming rare earths

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Development of Public Housing Post-reform china

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china & World Economy 2017年第4期25卷 60-77页

作者： Jie Chen Lingzhen Yao Hongwei Wang Professor School of Public Economics and Administration Shanghai University of Finance and Economics China Professor Shanghai Lixin University of Finance and Accounting China

This paper explores the dynamic nature of the transformation of public housing regimes in urban china since the abolishment of the urban welfare housing system in the late 1990s. We summarize the latest progress in the development of public housing in post- reform china and investigate the driving forces behind these developments. A close examination of the public rental housing program in Shanghai helps to show that the recent revival of public housing in Chinese cities is mostly driven by the desire for economic growth. We conclude that the state provision of housing could be a short-run state remedy to alleviate economic imbalance and social inequality. However, in the long run china needs to seek more effective solutions to solve the low-income population＇s housing affordability problems.

关键词： china housing policy housing regime public housing

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Petrology and Geochemistry of the Dangqiong Ophiolite,Western Yarlung-Zangbo Suture Zone,Tibet,china

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Acta Geologica Sinica(English Edition) 2019年第2期93卷 344-361页

作者： XU Xiangzhen YANG Jingsui XIONG Fahui GUO Guolin CARMA(Center for Advanced Research on Mantle) Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of Geology Chinese Academy of Geological Sciences State Key Laboratory Breeding Base of Nuclear Resources and Environment East China Institute of Technology

The Dangqiong ophiolite, the largest in the western segment of the Yarlung-Zangbo Suture Zone(YZSZ)ophiolite belt in southern Tibet, consists of discontinuous mantle peridotite and intrusive mafic rocks. The former is composed dominantly of harzburgite, with minor dunite, locally lherzolite and some dunite containing lenses and veins of chromitite. The latter, mafic dykes(gabbro and diabase dykes), occur mainly in the southern part. This study carried out geochemical analysis on both rocks. The results show that the mantle peridotite has Fo values in olivine from 89.92 to 91.63 and is characterized by low aluminum contents(1.5–4.66 wt%) and high Mg# values(91.06–94.53) of clinopyroxene. Most spinels in the Dangqiong peridotites have typical Mg# values ranging from 61.07 to 72.52, with corresponding Cr# values ranging from 17.67 to 31.66, and have TiO2 contents from 0 to 0.09%, indicating only a low degree of partial melting(10–15%). The olivine-spinel equilibrium and spinel chemistry of the Dangqiong peridotites suggest that they originated deeper mantle(>20 kbar). The gabbro dykes show N-MORB-type patterns of REE and trace elements. The presence of amphibole in the Dangqiong gabbro suggests the late-stage alteration of subduction-derived fluids. All the lherzolites and harzburgites in Dangqiong have similar distribution patterns of REE and trace elements, the mineral chemistry in the harzburgites and lherzolites indicates compositions similar to those of abyssal and forearc peridotites, suggesting that the ophiolite in Dangqiong formed in a MOR environment and then was modified by late-stage melts and fluids in a suprasubduction zone(SSZ) setting. This formation process is consistent with that of the Luobusa ophiolite in the eastern Yarlung-Zangbo Suture Zone and Purang ophiolite in the western Yarlung-Zangbo Suture Zone.

关键词： gabbro mantle peridotite Dangqiong ophiolite Yarlung-Zangbo Suture Zone Tibet

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Stability of C-regularized Semigroups

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Acta Mathematica Sinica,English Series 2004年第5期20卷 821-828页

作者： MiaoLI QuanZHENG DepartmentofMathematics SichuanUniversityChengdu610064P.R.China DepartmentofMathematicsCentralchina(Huazhong)NormalUniversity Wuhan430079P.R.China

Let T=(T(t))_(t≥0)be a bounded C-regularized semigroup generated by A on a Banach space X and R(C)be dense in *** show that if there is a dense subspace Y of X such that for every x ∈ Y,σ_u(A,Cx),the set of all points λ ∈ iR to which(λ-A)^(-1)Cx can not be extended holomorphically,is at most countable and σ_r(A)∩ iR=(?),then T is stable.A stability result for the case of R(C)being non-dense is also *** results generalize the work on the stability of strongly continuous semigroups.

关键词： C-regularized semigroups Generators Stable Hille-Yosida space

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CRITERIA FOR AN ANALYTIC FUNCTION BELONGING TO THE Q_K SPACES

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Acta Mathematica Scientia 2009年第1期29卷 33-44页

作者：乌兰哈斯 Department of Mathematics Shantou University

The author gives a mild integral condition in a nondecreasing function K : [0, ∞) → [0, ∞), which is sufficient and the best possible to ensure that f is a Bloch function if and only if f belongs to QK, a Mbius-invariant space of functions analytic in the unit disk. Their contributions are slight improvements of known results, and the proofs presented here are independently developed. The corresponding results for meromorphic case are also given.

关键词： Areally mean q-valent circumferentially mean q-valent QK spaces

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