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synthesis and electrocatalytic applications of flower-like motifs and associated composites of nitrogen-enriched tungsten nitride(W2N3)

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Nano Research 2020年第5期13卷 1434-1443页

作者： sha Tan Brian M.Tackett Qun He Ji Hoon Lee Jingguang G.Chen stanislaus s.Wong Department of Chemistry State University of New York at Stony BrookStony BrookNY 11794-3400USA Department of Chemical Engineering Columbia UniversityNew YorkNY 10027USA Chemistry Department Building 555Brookhaven National LaboratoryUptonNY 11973USA

We have sought to improve the electrocatalytic performance of tungsten nitride through synthetic control over chemical composition and *** particular,we have generated a thermodynamically unstable but catalytically promising nitrogen-rich phase of tungsten via a hydrothermal generation of a tungsten oxide intermediate and subsequent annealing in *** net product consisted of three-dimensional(3D)micron-scale flower-like motifs of W2N3;this architecture not only evinced high structural stability but also incorporated the favorable properties of constituent two-dimensional *** a performance perspective,as-prepared 3D W2N3 demonstrated promising hydrogen evolution reaction(HER)activities,especially in an acidic environment with a measured overpotential value of−101 mV at a current density of 10 mA/cm^*** further enhance the electrocatalytic activity,small amounts of precious metal nanoparticles(such as Pt and Au),consisting of variable sizes,were uniformly deposited onto the underlying 3D W2N3 motifs using a facile direct deposition method;these composites were applied towards the CO2 reduction reaction(CO2RR).A highlight of this series of experiments was that Au/W2N3 composites were found to be a much more active HER(as opposed to either a CO2RR or a methanol oxidation reaction(MOR))catalyst.

关键词： tungsten nitride synthesis composite morphology control electrocatalysis

健康成人动脉粥样硬化斑块易感性和血栓形成的生物标志物变化与极端空气污染水平相关:北京AIRCHD研究

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中华高血压杂志 2019年第4期27卷 399-399页

作者：刘青叶鹏 Xu H Wang T Liu s brook RD Feng B Zhao Q song X Yi T Chen J Zhang Y Wang Y Zheng L Rajagopalan s Li J Huang W

空气污染与心血管事件恶化的病理生理机制尚不完全清楚。该文探讨环境空气污染是否可以触发易损斑块.通过全身炎症途径促进血栓形成。方法:在北京AIRCHD研究中.2014-2016年间对73名健康成年人[年龄(23.3±5.4)岁]进行了随访。研究者使... 详细信息

空气污染与心血管事件恶化的病理生理机制尚不完全清楚。该文探讨环境空气污染是否可以触发易损斑块.通过全身炎症途径促进血栓形成。方法:在北京AIRCHD研究中.2014-2016年间对73名健康成年人[年龄(23.3±5.4)岁]进行了随访。研究者使用线性混合效应模型评估了空气污染物与动脉粥样硬化斑块易损性、血栓形成和炎症相关生物标志物之间的关系,并使用中介效应分析(mediation analyses)探讨涉及的生物学途径。通过受试者工作特征(receiver operating characteristic,ROC)曲线分析评估每种生物标记物预测环境空气污染暴露的能力。

关键词：动脉粥样硬化斑块空气污染物生物标志物血栓形成健康成人北京污染水易感性

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任博克《庄子》英译再讨论

商丘师范学院学报 2019年第7期35卷 1-22页

作者：任博克林明照赖锡三美国芝加哥大学神学院中国台湾大学哲学系中国台湾中山大学

缘起:2019年,任教授将再版《庄子》最新英译,一者将完整译出《庄子》33篇全文,二者针对2009年英译本给予精益求精。中国台湾学者近年与任教授展开了《庄子》核心思想的深入对谈,如今双方希望在任教授最新全译本出版前,能针对其英译背后... 详细信息

缘起:2019年,任教授将再版《庄子》最新英译,一者将完整译出《庄子》33篇全文,二者针对2009年英译本给予精益求精。中国台湾学者近年与任教授展开了《庄子》核心思想的深入对谈,如今双方希望在任教授最新全译本出版前,能针对其英译背后的多重考虑,进行思想细节的切磋琢磨。

关键词：《庄子》工夫论心止于符

Kinetic studies of Electrochemical Oxidation of 1,3-Benzenedithiol

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Chemical Research in Chinese Universities 1993年第3期9卷 231-239页

作者： H.s.Lee X.Q.Yang J.McBreen T.A.skotheim brookhaven National Laboratory Upton NY 11973 U.S.A. Brookhaven National Laboratory Upton NY 11973 U.S.A. Brookhaven National Laboratory Upton NY 11973 U.S.A. Moltech Corporation Stony Brook NY 11790-3350 U.S.A.

The electrochemical oxidation of 1, 3-benzenedithiol was investigated in a 0. 100 mol/L tetrabutylammonium perchlorate/acetonitrile electrolyte. The electrochemical techniques used were potential sweep, bulk electrolysis, rotating disc and the potential step method. The combination of the techniques yielded the number of electrons transferred per molecule, the reaction order, the transfer coefficient, the diffusion coefficient and concentration of dithiol anions, the standard heterogeneous rate constant as well as the formal potential and equilibrium constant of the preceeding dissociation reaction. This paper also illustrates the methods for studying the electrode kinetics of reactions which (a) involve a chemical reaction preceeding the electron-transfer process, (b) have insoluble polymer products, and (c) are totally irreversible.

关键词： Electrochemical oxidation 1,3-Benzenedithiol Electrode kinetics Organ-ic disulfide

Hydrothermal fabrication of selectively doped organic assisted advanced ZnO nanomaterial for solar driven photocatalysis

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Journal of Environmental sciences 2015年第8期27卷 248-255页

作者： K.Namratha K.Byrappa s.Byrappa P.Venkateswarlu D.Rajasekhar B.K.Deepthi Center for Material science and Technology Vijnan Bhavan Manasagangotri P.B.No 21 University of Mysore Department of Materials science and Engineering Stony Brook University Department of Chemistry Sri Venkateswara University

Hydrothermal fabrication of selectively doped（Ag＋＋ Pd3＋） advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions（autogeneous; 150°C）.Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, UV–Vis spectroscopy and scanning electron microscopy（sEM）. The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye,Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.

关键词： Hydrothermal technique Gluconic acid surface modification selectively doped ZnO Photocatalytic degradation

Evolution of Morphology and structure During Crystallization and Melting in syndiotactic Polypropylene

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应用化学 2001年第5期18卷 280-288页

作者： Zhi-Gang WANG Benjamin s.HsIAO Charles C.HAN state University of New York at stony brook Department of ChemistryStony BrookNY 11794-3400 Polymers Division and Center for Neutron Research National Institute of Standards and TechnologyGaithersburgMD 20899

structure and morphology development during isothermal crystallization and subsequent melting of syndiotactic polypropylene(sPP) was studied by time-resolved simultaneous small-angle X-ray scattering(sAXs) and wide-angle X-ray diffraction(WAXD) methods with synchrotron radiation and differential scanning calorimetry(DsC). The time and temperature dependent parameters such as long period, L , crystal lamellar thickness, l c, amorphous layer thickness, l a, scattering invariant, Q , crystallinity, X c, lateral crystal sizes, L 200 and L 020 , and unit cell parameters a and b were extracted from sAXs and WAXD profiles. Decreasing long period and crystal thickness indicate that thinner secondary crystal lamellae are formed. The decreases in unit cell parameters a and b during isothermal crystallization process suggest that crystal perfection takes place. The changes in the morphological parameters (the invariant, Q , crystallinity, X c, long period, L , and the crystal thickness, l c) during subsequent melting were found to follow a two-stage melting process, corresponding to the dual endotherm behavior in the DsC scan. We conclude that the dual melting peaks are due to the melting of secondary and primary lamellae(first peak) and the subsequent recrystallization-melting process(second peak). Additional minor endothermic peak located at the lowest temperature was also detected and might be related to melting of secondary, thinner and defective lamellae. WAXD showed that during melting, thermal expansion was greater along the b axis than that along the a axis.

关键词：间规聚丙烯结晶熔化晶体结构 DCs sAXs WAXD

structural characterization of carboxyl cellulose nanofibers extracted from underutilized sources

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science China(Technological sciences) 2019年第6期62卷 971-981页

作者： ZHAN ChengBo sHARMA Priyanka R. GENG LiHong sHARMA sunil K. WANG RuiFu JOsHI Ritika HsIAO Benjamin s. Department of Chemistry Stony Brook University Stony Brook NY 11794-3400 USA National Engineer Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing Engineering of Ministry of Education South China University of Technology Guangzhou 510640 China

Two different chemical methods, TEMPO-oxidation and nitro-oxidation, were used to extract carboxyl cellulose nanofibers(CNFs) from non-wood biomass sources(i.e., jute, soft and hard spinifex grasses). The combined TEMPO-oxidation and homogenization approach was very efficient to produce CNFs from the cellulose component of biomass;however, the nitrooxidation method was also found to be effective to extract CNFs directly from raw biomass even without mechanical *** effect of these two methods on the resulting cross-section dimensions of CNFs was investigated by solution small-angle Xray scattering(sAXs), transmission electron microscopy(TEM) and atomic force microscopy(AFM). The UV-Vis spectroscopic data from 0.1 wt% TEMPO-oxidized nanofiber(TOCNF) and nitro-oxidized nanofiber(NOCNF) suspensions showed that TOCNF had the highest transparency(> 95%) because of better dispersion, resulted from the highest carboxylate content(1.2 mmol/g). The consistent scattering and microscopic results indicated that TOCNFs from jute and spinifex grasses possessed rectangular cross-sections, while NOCNFs exhibited near square cross-sections. This study revealed that different oxidation methods can result in different degrees of biomass exfoliation and different CNF morphology.

关键词： cellulose nanofibers TEMPO-oxidation nitro-oxidation sAXs microscopy jute spinifex

Missing data and the accuracy of Bayesian phylogenetics

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植物分类学报 2008年第3期46卷 307-314页

作者： John J. WIENs Daniel s. MOEN Department of Ecology and Evolution Stony Brook University Stony Brook NY 11794-5245 USA

The effect of missing data on phylogenetic methods is a potentially important issue in our attempts to reconstruct the Tree of Life. If missing data are truly problematic, then it may be unwise to include species in an analysis that lack data for some characters (incomplete taxa) or to include characters that lack data for some species. Given the difficulty of obtaining data from all characters for all taxa (e.g., fossils), missing data might seriously impede efforts to reconstruct a comprehensive phylogeny that includes all species. Fortunately, recent simulations and empirical analyses suggest that missing data cells are not themselves problematic, and that in-complete taxa can be accurately placed as long as the overall number of characters in the analysis is large. How-ever, these studies have so far only been conducted on parsimony, likelihood, and neighbor-joining methods. Although Bayesian phylogenetic methods have become widely used in recent years, the effects of missing data on Bayesian analysis have not been adequately studied. Here, we conduct simulations to test whether Bayesian analyses can accurately place incomplete taxa despite extensive missing data. In agreement with previous studies of other methods, we find that Bayesian analyses can accurately reconstruct the position of highly incomplete taxa (i.e., 95% missing data), as long as the overall number of characters in the analysis is large. These results suggest that highly incomplete taxa can be safely included in many Bayesian phylogenetic analyses.

关键词：贝叶斯定理系统发生学数据缺失准确度

NUCLEAR DEALIGNMENT IN GAsEs

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Nuclear science and Techniques 1993年第3期4卷 146-150页

作者：朱升云 M.H. Rafailovich C.Alonso-Arias s.Vajda G.D.sprouse China Institute of Atomic Energy.Beijing 102413 state University of New York Stony Brook New York 11794 USA

The nuclear dealignment is studied during the slowing down process and after thermolization in different gases by the time differential perturbed angular distribution method. A large fraction of the initial nuclear alignment following the nuclear reaction can be preserved in gases with large moments of inertia, but only a small fraction in monoatomic gases such as the noble gases. The plunger experiment shows that the nuclear dealignment occurs during the slowing down process and not after thermolization.

关键词： Nuclear dealignment Gases Time differential perturbed angular distribution