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Computational fluid dynamics simulation of hydrodynamics in the riser of an external loop airlift reactor

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Particuology 2016年第4期14卷 95-101页

作者： Xuedong jiang ning Yang Bolun Yang Department of Chemical Engineering State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China Center for Mesoscience and State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Local hydrodynamics in the riser of an external loop airlift reactor （EL-ALR） are identified and the performances of three drag models are evaluated in computational fluid dynamics simulation. The simulation results show that the Schiller-Naumann drag model underestimated the local gas holdup at lower superficial gas velocity whereas the Tomiyama drag model overestimated that at higher superficial gas velocity. By contrast, the dual-bubble-size （DBS）-local drag model gave more reasonable radial and axial distri-butions of gas holdup in all cases. The reason is that the DBS-local drag model gave correct values of the lumped parameter, i,e., the ratio of the drag coefficient to bubble diameter, for varying operating conditions and radial positions. This ratio is reasonably expected to decrease with increasing superficial gas velocity and be smaller in the center and larger near the wall. Only the DBS-local drag model correctly reproduced these trends. The radial profiles of the axial velocity of the liquid and gas predicted by the DBS-local model also agreed well with experimental data.

关键词： Computational fluid dynamics External loop airlift reactor Drag model Gas holdup Mnltiscale Mesoscale

Analytical solution for the time-fractional heat conduction equation in spherical coordinate system by the method of variable separation

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Acta Mechanica Sinica 2011年第6期27卷 994-1000页

作者： Ting-Hui ning Xiao-Yun jiang School of Mathematics Shandong University 250100 Jinan China

In this paper,using the fractional Fourier law,we obtain the fractional heat conduction equation with a time-fractional derivative in the spherical coordinate *** method of variable separation is used to solve the timefractional heat conduction *** Caputo fractional derivative of the order 0 〈 α≤ 1 is *** solution is presented in terms of the Mittag-Leffler *** results are illustrated graphically for various values of fractional derivative.

关键词： Fractional Fourier law Fractional heat conduction equation - Spherical coordinate system - The separation of variables Mittag-Leffler function

Synthesis and Structural Characterization of a New Hydrogen-bonded Polyrotaxane of [Co(H_2O)_6]_(2+) with 1,1′-(Propane-1,3-diyl)dipyridinium-4-carboxylate

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Chinese Journal of Structural Chemistry 2006年第8期25卷 957-964页

作者： jiang ning-Yi LI Song-Lin Department of Chemistry College of Science Tianjin University Tianjin 300072 China

A new double betaine 1,1′-（propane-1,3-diyl）dipyridinium-4-carboxylate L has been synthesized. Reaction of 1, 1′-（propane-1,3-diyl）dipyridinium-4-carboxylate tetrahydrate 1 with Co（ClO4）2-6H2O leads to the formation of a new Co（Ⅱ） coordination compound, namely [Co（H2O）6]-2H2O-2L-2ClO4 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1. monoclinic, space group C2/c, a = 18.945（4）, b = 7.700（2）, c = l 1.888（2）A,β = 101.67（3）°, V = 1698.3（6） A^3, Z = 4, F（000） = 760.0, Dc = 1.402 g/cm^3, the final R = 0.0607 and wR = 0.1607 for 950 observed reflections （1 〉 2σ（I））; and those for 2： monoclinic, space group P21/c, a = 17.982（1）, b = 15.879 （1）, c = 7.0716（5）/A,β= 100.675（1）°, V= 1984.3（3） ,A^3 Z= 4, F（000） = 1010.0, Dc = 1.631 g/cm^3, the final R = 0.0316 and wR = 0.0896 for 3784 observed reflections （1 〉20（I））. Crystal structure analysis indicates that in 1, molecules of L in a ＂V-shaped＂ conformation are linked to chains sustained by O-H…O hydrogen bonds between carboxylate groups and solvent water molecules. The chains are joined by O-H…O and C-H…O hydrogen bonds to further expand into a three-dimensional structure. For 2, molecules of L in a ＂Z-shaped＂ conformation are linked by hydrogen bonds between carboxylate groups and aqua ligands to form a chain of loops running down the b axis. The （2D→2D） polythreading in compound 2 represents the mode of parallel interpenetration of 2D sheets, having polyrotaxane character.

关键词： 1,1′-(propane-1,3-diyl)dipyridinium-4-carboxylate polyrotaxane hydrogen bonding betaine derivative

Proximity association in polygynous western black crested gibbons(Nomascus concolor jingdongensis):network structure and seasonality

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Zoological Research 2013年第1期34卷 1-8页

作者： zhen-Hua GUAN Bei HUANG Wen-He ning Qing-Yong NI Xue-Long jiang State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoologythe Chinese Academy of SciencesKunming 650223China University of the Chinese Academy of Sciences Beijing 100049China College of Animal Science&Technology Sichuan Agriculture UniversityYa'an Sichuan 625014China

We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network *** spatial proximity changed seasonally and was affected by temperature and *** proximity association was not distributed randomly among *** was one explanation for the social structure,as offspring preferred to maintain close proximity with their *** proximity of infants to mothers decreased with age,and independent offspring had lower proximity to mothers than dependent *** found that the adult male had different proximity relationships with two different adult *** frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the *** avoidance and/or predation protection for dependent infants might explain the proximity relationship *** influenced group proximity association,with individual proximity increasing in the cold months and decreasing in the hot *** proximity decreased in months with higher anthropogenic disturbance.

关键词： Proximity Nomascus concolor Polygynous Social network

A new early warning method for dam displacement behavior based on non-normal distribution function

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Water Science and Engineering 2022年第2期15卷 170-178页

作者： zhen-xiang jiang Hui Chen School of Hydraulic and Ecological Engineering Nanchang Institute of TechnologyNanchang 330099China

Traditional methods for early warning of dam displacements usually assume that residual displacements follow a normal *** assumption deviates from the reality,thereby affecting the reliability of early warning results and leading to misjudgments of dam displacement *** solve this problem,this study proposed an early warning method using a non-normal distribution function.A new early warning index was developed using cumulative distribution function(CDF)*** method of kernel density estimation was used to calculate the CDF values of residual displacements at a single *** copula function was used to compute the CDF values of residual displacements at multiple *** results showed that,with residual displacements in a non-normal distribution,the early warning method proposed in this study accurately reflected the dam displacement behavior and effectively reduced the frequency of false *** method is expected to aid in the safe operation of dams.

关键词： Non-normal distribution Dam displacement Early warning index Kernel density estimation Copula function

Advances in green synthesis and applications of graphene

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Nano Research 2021年第11期14卷 3724-3743页

作者： Qi Yu Jianchao jiang Liyun jiang Qingqing Yang ning Yan Shaanxi Key Laboratory of Catalysis School of Materials Science and EngineeringShaanxi University of TechnologyHanzhong723001China Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore117585Singapore

Green synthesis has grabbed appreciable attention to eliminate the negative effects associated with various chemical processes. Due to the unparalleled electrical, mechanical, thermal and excellent physical properties, graphene, as the thinnest two-dimensional material with high surface area, has the unfathomable potential in the domain of green chemistry in terms of both synthesis and application. In this regard, we present an overview of the research progresses on the greener synthesis of graphene, including micromechanical exfoliation, chemical reduction of graphene oxide (GO), chemical vapor synthesis and popping of GO. Meanwhile, various applications of graphene pertinent to sustainable developments, such as energy storage, catalysis, electrochemistry, fuel cell, supercapacitor and biomedicine have also been highlighted.

关键词： green chemistry graphene synthesis catalysis supercapacitor

Cybersecurity Named Entity Recognition Using Bidirectional Long Short-Term Memory with Conditional Random Fields

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Tsinghua Science and Technology 2021年第3期26卷 259-265页

作者： Pingchuan Ma Bo jiang Zhigang Lu ning Li zhengwei jiang School of Cyber Security University of Chinese Academy of SciencesBeijing 100049China Institute of Information Engineering Chinese Academy of SciencesBeijing 100093China

Network texts have become important carriers of cybersecurity information on the *** texts include the latest security events such as vulnerability exploitations,attack discoveries,advanced persistent threats,and so *** cybersecurity entities from these unstructured texts is a critical and fundamental task in many cybersecurity ***,most Named Entity Recognition(NER)models are suitable only for general fields,and there has been little research focusing on cybersecurity entity extraction in the security *** this end,in this paper,we propose a novel cybersecurity entity identification model based on Bidirectional Long Short-Term Memory with Conditional Random Fields(Bi-LSTM with CRF)to extract security-related concepts and entities from unstructured *** model,which we have named XBi LSTM-CRF,consists of a word-embedding layer,a bidirectional LSTM layer,and a CRF layer,and concatenates X input with bidirectional LSTM *** extensive experiments on an open-source dataset containing an office security bulletin,security blogs,and the Common Vulnerabilities and Exposures list,we demonstrate that XBi LSTM-CRF achieves better cybersecurity entity extraction than state-of-the-art models.

关键词： security blogs Long Short-Term Memory(LSTM) Named Entity Recognition(NER)

Thermoelectric properties of Bi0.5Sb1.4-xNaxIn0.1Te3 alloys

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Rare Metals 2019年第12期38卷 1187-1192页

作者： Yue-zhen jiang Xing-Kai Duan School of Electronic Engineering Jiujiang UniversityJiujiang 332005China School of Mechanical and Materials Engineering Jiujiang UniversityJiujiang 332005China

The Bi(0.5)Sb(1.4-x)NaxIn(0.1)Te3(x=0.02-0.20)alloys were fabricated by high vacuum melting and hotpressing *** phase structures and morphology of the bulk samples were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM),*** of In and Na co-doping on the electrical and thermal transport properties were studied from room temperature to 500 *** coefficient of the Bi(0.5)Sb(1.5)Te3 can be enhanced by substituting Sb with In and Na at near room *** electrical conductivity of the In and Na co-doped samples is lower than that of the Bi(0.5)Sb(1.5)Te3 alloy from room temperature to 500 *** and Na co-doping of appropriate percentage optimizes the thermal conductivity of the Bi(0.5)Sb(1.5)Te3 *** minimum value of thermal conductivity of Bi(0.5)Sb(1.36)Na(0.04)In(0.1)Te3 alloy is 0.45 W·m^(-1) K^(-1) at 323 *** leads to a great improvement in the thermoelectric figure of merit(zT).The maximum zT value reaches 1.42 at 323 K.

关键词： Microstructure Co-doping Thermal conductivity Electrical properties

Cronkhite-Canada syndrome with steroid dependency: A case report

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World Journal of Clinical Cases 2021年第14期9卷 3466-3471页

作者： Dan jiang Guo-Du Tang Ming-Yu Lai zhen-ning Huang Zhi-Hai Liang Department of Gastroenterology The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND Cronkhite-Canada syndrome(CCS)is a rare nonhereditary disease characterized by chronic diarrhoea,diffuse gastrointestinal polyposis and ectodermal *** lethality of CCS can be up to 50%if it is untreated or if treatment is delayed or *** than 35%of the patients do not achieve long-term clinical remission after corticosteroid administration,with relapse occurring during or after the cessation of glucocorticoid *** optimal strategy of maintenance therapy of this disease is *** SUMMARY A 47-year-old man presented to the hospital with a 3-mo history of frequent watery diarrhoea,accompanied by macular skin pigmentation that included the palms and soles,and onychodystrophy of the fingernails and *** and colonoscopy revealed numerous polyps in the stomach and *** other possibilities were ruled out by a series of examinations,CCS was diagnosed and treated with *** patient took prednisone for more than 1 year before achieving complete resolution of his symptoms and endoscopic *** patient was then given prednisone 5 mg/d for 6 mo of maintenance *** clinical improvement and polyp regression,prednisone was *** mo after the discontinuation of prednisone,the diarrhoea and gastrointestinal polyps ***,the patient was given the same dose of prednisone,and complete remission was achieved *** It is necessary to extend the duration of prednisone maintenance therapy for *** is still effective when readministered after *** endoscopy at intervals of 1 year or less is recommended to assess mucosal disease activity.

关键词： Cronkhite-Canada syndrome Endoscopy Prednisone Relapse Maintenance therapy Case report