论文李新亮的共享数据ZhaoR-entropy-2014

COVER Volatile organic compounds (VOCs) cause serious atmospheric pollution, and most of them are harmful to human health. Catalytic oxidation is an efficient method for the removal of VOCs. The key issue is the development of high-performance catalysts. Although transition-metal oxides (MOx) can act as catalysts, their performance is poor because of their low surface areas. High dispersion of Mn+ or MOx can be achieved by the incorporation of Mn+ ions into a framework consisting of high- surface-area mesoporous molecular sieves or loading the MOx onto the surface of a porous material. Mesoporous silicas such as SBA-15 have received much attention as catalysts because of their large pores, thick pore walls, and good hydrothermal stabilities. We synthesized high-surface-area, well- ordered mesoporous Fe-incorporated SBA-15 (Fe-SBA-15) and SBA-15-supported FeOx (FeOx/SBA- 15), using one-step synthetic and incipient wetness impregnation methods, respectively. For a similar Fe surface density and space velocity, the Fe-SBA-15 catalysts showed better activities than the FeOx/ SBA-15 catalysts in the catalytic combustion of toluene. We concluded that the good performance of Fe-SBA-15 is associated with its large surface area, high Fe species dispersion, and good low- temperature reducibility. The cover image shows the fabrication process, pore structure feature, and toluene oxidation pathway of the Fe-SBA-15 and FeOx/SBA-15 catalysts (see the article by Yujuan Zhang et al. on page 3993). Copyright Information For Authors As soon as an article is accepted for publication, authors will be requested to assign copyright of the article (or to grant exclusive publication and dissemination rights) to Science China Press and Springer. This will ensure the widest possible protection and dissemination of information under copyright laws. 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Science China Press and Springer-Verlag Berlin Heidelberg Volume 59 Number 31 November 2014 Vol. 59 No. 31 November 5, 2014 (Published three times every month) Supervised by Chinese Academy of Sciences Sponsored by Chinese Academy of Sciences and National Natural Science Foundation of China Published by Science China Press and Springer-Verlag Berlin Heidelberg Subscriptions China Science China Press, 16 Donghuangchenggen North Street, Beijing 100717, China Email: Fax: 86-10-64016350 North and South America Springer New York, Inc., Journal Fulfillment, P.O. Box 2485, Secaucus, NJ 07096 USA Email: journals-ny Fax: 1-201-348-4505 Outside North and South America Springer Customer Service Center, Customer Service Journals, Haberstr. 7, 69126 Heidelberg, Germany Email: subscriptions Fax: 49-6221-345-4229 Printed by Beijing Artownprinting Co., Ltd., Chuangyeyuan Road, Taihu Town, Tongzhou District, Beijing 101116, China Edited by Editorial Board of Chinese Science Bulletin, 16 Donghuangchenggen North Street, Beijing 100717, China Editor-in-Chief Xiao-Ya Chen CN 11-1785/N 广告经营许可证: 京东工商广字第0429号 邮发代号: 80-214 (英) 国内每期定价: 120元 i CONTENTS CONTENTS | | | Volume 59 Number 31 November 2014 SPECIAL TOPIC: Advanced Catalytic Materials for Environmental Application EDITORIAL 3955 Editorial: advanced catalytic materials for environmental application Junhua Li ARTICLES 3956 The influence of molar ratios of Ce/Zr on the selective catalytic reduction of NOx with NH3 over Fe2O3- WO3/CexZr1xO2 (0 x 1) monolith catalyst Haidi Xu Yi Cao Yun Wang Zhitao Fang Tao Lin Maochu Gong Yaoqiang Chen 3966 The poisoning and regeneration effect of alkali metals deposed over commercial V2O5-WO3/TiO2 catalysts on SCR of NO by NH3 Fengyu Gao Xiaolong Tang Honghong Yi Shunzheng Zhao Tongtong Zhang Dong Li Ding Ma 3973 Selective catalytic reduction of NOx by hydrogen over modified Pd/TiO2-Al2O3 catalyst under lean-burn conditions Kaijiao Duan Zhiming Liu Lei Yuan 3980 Selective catalytic oxidation of ammonia to nitrogen over orderly mesoporous CuFe2O4 with high specific surface area Wenrui Yue Runduo Zhang Ning Liu Biaohua Chen 3987 Influence of interactions between chromium and cerium on catalytic performances of CrOxCeO2/Ti- PILC catalysts for deep oxidation of n-butylamine Shanshan Yang Qinqin Huang Renxian Zhou 3993 Preparation and catalytic performance of Fe-SBA-15 and FeOx/SBA-15 for toluene combustion Yujuan Zhang Jiguang Deng Lei Zhang Hongxing Dai 4003 Different mechanisms between reactions of soot with gaseous and adsorbed NO2 Yexin Zhang Shaojie Chen Qian Li Zhaoliang Zhang Jian Zhang 4008 Mesoporous iron oxide-silica supported gold catalysts for low-temperature CO oxidation Weidong Zhang Xiaofei Lu Weili Zhou Feng Wu Jinjun Li INVITED REVIEW Neuroscience 4014 The neuroprotective effect of L-Theanine and its inhibition on nicotine dependence Yan Zhao Baolu Zhao PROGRESS Cell Biology 4020 Research progress in quantifying the mechanical properties of single living cells using atomic force microscopy Mi Li Lianqing Liu Ning Xi Yuechao Wang REVIEWS Cell Biology 4030 Recent advances in brown adipose tissue biology Yanyan Shen Xiaomeng Liu Meng Dong Jun Lin Qianwei Zhao HyuekJong Lee Wanzhu Jin Neuroscience 4041 New strategies for the repair of spinal cord injury Zhourui Wu Ziru Zhao Yan Yu Xiao Hu Wei Xu Zhili Zeng Yi Eve Sun Liming Cheng Go To Website ii CONTENTS CONTENTS | | | ARTICLES Crop Genetics 4050 Clustered spikelets 4, encoding a putative cytochrome P450 protein CYP724B1, is essential for rice panicle development Min Guo Yi-Hao Yang Min Liu Qing-Cai Meng Xiu-Hong Zeng Ling-Xia Dong Shu-Zhu Tang Ming-Hong Gu Chang-Jie Yan Cell Biology 4060 Role of Ppt1 in multiple stress responses in Candida albicans Kangdi Hu Wanjie Li Jiaxin Gao Qizheng Liu Haitao Wang Yue Wang Jianli Sang Neuroscience 4069 Resting state brain default network in patients with motor aphasia resulting from cerebral infarction Xin Wang Meihao Wang Weizhuo Wang Huiru Liu Jiejie Tao Chuang Yang Jiance Li 4077 Factors affecting the voxel-based analysis of diffusion tensor imaging Jianli Wang Binbin Nie Haitao Zhu Hua Liu Jingjuan Wang Shaofeng Duan Baoci Shan Geology 4086 Quadrapyrgites from the lower Cambrian of South China: growth pattern, post-embryonic development, and affinity Yunhuan Liu Yong Li Tiequan Shao Huaqiao Zhang Qi Wang Jinpeng Qiao 4096 Changes in plant diversity on the Chinese Loess Plateau since the Last Glacial Maximum Shujun Zhao Zhongli Ding 4101 Pollen-inferred Holocene vegetation and climate histories in Taro Co, southwestern Tibetan Plateau Qingfeng Ma Liping Zhu Xinmiao L Yun Guo Jianting Ju Junbo Wang Yong Wang Lingyu Tang 4115 Higher sea surface temperature in the northern South China Sea during the natural warm periods of late Holocene than recent decades Hong Yan Liguang Sun Da Shao Yuhong Wang Gangjian Wei Atmospheric Science 4123 Response of the East Asian summer monsoon to large volcanic eruptions during the last millennium Wenmin Man Tianjun Zhou 4130 Features of tropical cyclone landfalls over East Asia corresponding to three types of Pacific warming decaying phase Yao Ha Zhong Zhong Fluid Mechanics 4137 Entropy and its application in turbulence modeling Rui Zhao Jili Rong Xinliang Li Materials Science 4142 Preparation and optical properties of waterborne acrylic-based cool white coatings Shengjun Cheng Hongjiang Liu Yanfeng Gao 4147 Low melting point nanocrystalline SnAg solder synthesized by a refined chemical reduction method Bingge Zhao Weipeng Zhang Changdong Zou Qijie Zhai Steve F. A. Acquah Yulai Gao Artificial Intelligence 4152 Active set strategy of optimized extreme learning machine Xiao-Jian Ding Bao-Fang Chang ArticleFluid Mechanics Entropy and its application in turbulence modeling Rui ZhaoJili RongXinliang Li Received: 12 October 2013/Accepted: 18 March 2014/Published online: 31 July 2014 ? Science China Press and Springer-Verlag Berlin Heidelberg 2014 AbstractThe entropy concept was introduced into the turbulence modeling strategy in the present work. First, the turbulent boundary-layer was described from the point of energy dissipation. Based on the theoretical analysis and direct numerical simulations, the relationship between the entropy increment and viscosity dissipation was systemat- ically investigated. Then, an entropy function fswas pro- posed to distinguish the turbulent boundary-layer from the external fl ow. This function is universal, independent of the infl ow conditions or any specifi c turbulence model. With this function, a new version of delayed-detached-eddy simulation method SDES was constructed and verifi ed with the supersonic boundary-layer fl ow and the cavity-ramped fl ow. Initial results showed that this method could suc- cessfully avoid the modeled stress depletion problem inherited from the original DES method. KeywordsEntropy ? Turbulence boundary-layer ? Turbulence modeling ? RANS/LES hybrid method 1 Introduction Entropy, in addition to energy, is an essential physical quantity in thermodynamics. It serves as a measure of the irreversibility of a process and a criterion describing the thermal equilibrium of a system. Because of its general features, the entropy concept has been extended to many other fi elds, such as thermodynamic optimization and computational techniques 16. As for the turbulent fl ow, McEligot et al. 7 concluded that about two-thirds or more of entropy generation occurs in the turbulent boundary-layer and they examined the effects of Reynolds number and streamwise pressure gra- dients on entropy generation. Moore et al. 8 and other researchers 9, 10 developed a series of numerical models for the turbulent entropy production terms. Recently, Zhao et al. 11 systematically investigated the characteristics of entropy increment in turbulent boundary-layer based on direct numerical simulation (DNS) data. With this concept, they revised the length scale of BaldwinLomax model, enhancing its robustness for complex fl ows. They further proposed an entropy-based shielding function to safely preserve the RANS resolved region in the boundary-layer and constructed a new version of delayed-detached-eddy simulation method SDES to avoid the modeled stress depletion (MSD) problem 12. Although the recent achievements have revealed another potential capability of entropy in turbulence modeling, the defi nition of entropy expression for turbulent boundary-layer is still not com- prehensive. This paper continues to extend the competence of the entropy concept for both compressible and incom- pressible fl ows and revisits the SDES method in particular. Virtually, all fl ows of practical engineering interests are turbulent. Due to the irregular motion of turbulence, the transportations of mass, momentum, and energy are enhanced, while extra-energy is dissipated. In the near-wall region, as for the fi erce turbulent fl uctuation and wall fri- cation, a portion of mechanical energy is irreversibly transformed into internal energy, i.e., the entropy increases. Following McEligot et al. 7, we here defi ne turbulence R. Zhao (1 where cv = R/(c - 1) is the specifi c heat at constant volume, R is the gas constant, c = 1.4 is the specifi c heat ratio, and T, p, and q are the local temperature, pressure, and density, respectively, subscript ? means the quantity in the far fi eld. For incompressible fl ows, s can be expressed by Ds cvln T T1 :2 On the other hand, the balance equation of s is written as follows 9: ds 1 q o oxj ?qj T ?dt dsc w qTdt dsT U qTdt dsl ;3 where qj k oT oxj is the heat transfer, k lcR c?1Pr is the thermal conductivity, Pr = 0.7 is the laminar Prandtl number, w k T oT oxj oT oxj ? , U l 2 oui oxj ouj oxi ?2 , and l is the molecular viscosity. On the right side of Eq. (3), the fi rst term dscis the thermal conductive term, whose value may be either neg- ative or positive. The other two terms stand for the entropy production terms. dsTrepresents the entropy generation due to heat transfer across fi nite temperature gradients, while dslrepresents the local entropy generation by the viscous dissipation. These two positive terms apply to both compressible and incompressible Newtonian fl uids 9. As the term dscincludes the second derivative of T which may cause numerical singularity at the adiabatic wall, we sim- ply neglect this term at this step. By combing Eq. (3) with (1) or (2) (depending on the fl ow condition), the entropy increment caused by the viscous dissipation can be deduced as follows: Dsvis dsl dsT dsl ? Ds U U w ? Ds:4 For turbulent fl ows, Eq. (4) is Reynolds-averaged and the turbulent terms are modeled with the Moore model 8: D? svis 1 lt=l?U 1 lt=l?U 1 kt=k?w ? D? s ? U ? U a?w ? D? s; 5 in which a lPrtltPr lPrtltPrt, Prt = 0.9 is turbulent Prandtl number, ltis the turbulent viscosity, and the instantaneous variables in ? U, ? w, D? s are replaced with the corresponding averaged one, respectively. When the potential fl ows pass the wall, the mechanical energy is dissipated to zero due to the viscous frication. Naturally, the value of D? svisat the wall is directly related to infl ow speeds, i.e., it varies orders of magnitude from the low-speed fl ows to hypersonic fl ows. In order to obtain D? svisnormalized for modeling convenience, the following procedures are taken. For adiabatic boundary-layer fl ows, the maximum entropy increment could be expressed as follows 13: Dsmax cvln p1 pw ?1 c ? 1 2 Ma2 1 ?c? ;6 where the subscript w means the quantity at the wall. Since p?pwin general, we simplify Eq. (6) and assume Dsmax as follows: Dsmax cvln 1 c ? 1 2 Ma2 1 ?c :7 With D? svisnormalized by Dsmax(Eq. (7), a novel entropy concept, named entropy increment ratio ? svis, is proposed: ? svis D? svis Dsmax ? U ? U a?w ? D? s Dsmax :8 ? svisrepresents the viscous dissipation rate of per unit mechanicenergy,whosebehaviorissystematically investigated based on the DNS data (Table 1). Figure 1 compares the profi les of ? svisand the streamwise velocity ? u normal to the wall with different infl ow Mach numbers. The profi le of ? svisdepicts a consistent trend as that of the velocity? u,andtheboundary-layerregioniswell represented by ? svis0. Moreover, the value of ? svis Table 1 Simulation conditions for the boundary-layer fl ows (DNS) MaReTw/T?Tw/Tr Case 10.75.0 9 1041.0981.003 Case 22.256.35 9 1051.90.961 Case 362.0 9 1066.980.878 Ma infl ow Mach number, Re Reynolds number per inch, Twwall temperature, T? infl ow temperature, and Trrecovery temperature 4138Chin. Sci. Bull. (2014) 59(31):41374141 123 approaches unity toward the wall. This character is convenientastheweakdependenceofmodelsor physical parameters on fl ow conditions is always desired. Remember that entropy may also increase in other regions, such as the areas where shock waves and detached vortex exist. To avoid this defect, an entropy function is proposed to confi ne the predicted turbulent boundary-layer near the wall: fs 1:0 ? tanh ? svis=l3 s ?; 9 where lsis the length-scale ratio, which is designed to be less than 1.0 in the boundary-layer and increase quickly in the external fl ows. We construct lsfollowing the spirit of DES97 14, but with minor revision: ls Csfa1;a2d=CDESD;? svis0:05; d=CDESD;otherwise, ? 10 in which Cs= 0.12 is an empirical constant, f(a1,a2) is an anisotropic function recommended by Scotti et al. 15, d is the distance normal to the wall, CDES= 0.65, and D is the grid spacing defi ned by D = max(Dx, Dy, Dz). The distributions of ? u, ? svisand fsare investigated in the 24? supersonic compression corner fl ow (DNS) 11. As Fig. 2 indicates, the general velocity criterion (? u/U? 95 % or 99 %) fails to denote the boundary-layer range, especially in the corner area where the velocity is decel- erated by shocks. Comparatively, the turbulent boundary- layer predicted by ? svisand fsbased on the viscosity dissi