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Heat transfer analysis of the bent cooling channels in SSRF light-blocked components

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Nuclear Science and Techniques 2012年第6期23卷 321-327页

作者： JIN Jianfeng CHEN Haibo XIAO Weiling cheng wenlong WANG Naxiu Department of Modern Mechanics University of Science and Technology of China Beijing Institute of Space Long March Vehicle Department of Thermal Science and Energy Engineering University of Science and Technology of China Shanghai Institute of Applied Physics Chinese Academy of Sciences

The front end light-blocked components of the third generation of synchrotron radiation facility,which are subjected to high heat load,are cooled with flowing water through the cooling *** convective heat transfer coefficient and the flow resistance(or pressure drop) are two important parameters for evaluating the heat transfer performance of the cooling channels and should be strictly *** this research,two typical bent cooling channels in Shanghai Synchrotron Radiation Facility(SSRF) were modeled and their in-pipe turbulent flows were *** two criteria obtained under different channel water velocities met the SSRF technical *** reduce the total pressure drop,arc transitions were proposed to replace the right angle transitions in the cooling *** the same time,an experiment was performed to measure the convective heat transfer coefficient of a typical bent channel *** experimental results were in good agreement with the simulation ones.

关键词：冷却通道 SSRF 弯曲通道传热分析上海同步辐射装置对流换热系数光阻流动阻力

Matryoshka-caged gold nanorods： Synthesis, plasmonic properties, and catalytic activity

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Nano Research 2016年第2期9卷 415-423页

作者： Wei Xiong Debabrata Sikdar Lim Wei Yap Pengzhen Guo Malin Premaratne Xinyong Li wenlong cheng Department of Chemical Engineering Monash University Clayton VIC 3800 Australia The Melbourne Centre for Nanofabrication 151 Wellington Road Clayton VIC 3168 Australia Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemicals School of Environmental Sciences and Technology Dalian University of Technology Dalian 116024 China Advanced Computing and Simulation Laboratory (AχL) Department of Electrical and Computer Systems Engineering Monash University Clayton VIC 3800 Australia

Matryoshka-caged gold nanorods （mCGNRs） were successfully synthesized by alternating between a seed-mediated silver-coating method and galvanic replacement reactions （GRRs）. As the number of matryoshka layers of the mCGNRs increased, the plasmon resonance peak broadened and was red-shifted, and the catalytic activity towards the reduction of 4-nitrophenol （4-NTP） increased. When mCGNRs with 6 layers were used as nanocatalysts in the reduction of 4-nitrophenol, the reaction rate coefficient was 5.2- and 3.7-times higher than that of the gold-nanorod- and caged-gold-nanorod-catalyzed reductions of 4-nitrophenol, respectively. In addition, the surface-plasmon-resonance-based absorption of light enhanced the catalytic performance of the mCGNRs. With the support of a polyurethane foam, the mCGNRs synthesized in this study can be applied as recydable heterogeneous catalysts for the reduction of 4-nitrophenol.

关键词： matryoshka-caged gold nanorods galvanic replacement reaction 4-nitrophenol catalysis surface plasmon resonance

Recent advances in the rational design of electrocatalysts towards the oxygen reduction reaction

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Chinese Journal of Catalysis 2017年第6期38卷 951-969页

作者： Jianfei Kong wenlong cheng Yancheng Vocational Institute of Health Sciences Yancheng 224000 Jiangsu China Department of Chemical Engineering Faculty of Engineering Monash University Clayton VIC 3800 Australia Melbourne Centre for Nanofabrication Clayton VIC 3168 Australia

The quest for low‐cost yet efficient non‐Pt electrocatalysts for the oxygen reduction reaction(ORR)has become one of the main focuses of research in the field of catalysis,which has implications for the development of the next generation of greener fuel ***,we comprehensively describe the'big picture'of recent advances made in the rational design of ORR electrocatalysts,including molecule‐based,metal‐oxide‐based,metal‐nanomaterial‐based and two‐dimensional *** metals can fabricate molecular electrocatalysts with N4‐macrocycles such as porphyrin‐class compounds and the so‐formed M-N-C active centre plays a crucial role in determining the catalytic performances towards the ***‐IV and‐V Transition metal oxides represent another class of promising alternative of Pt‐based catalysts for the ORR which catalytic activity largely depends on the surface structure and the introduction of surface *** advances in synthesis of metallic nanoparticles(NPs)allow for precise control over particle sizes and shapes and the crystalline facets exposed to enhance the ORR performance of ***‐dimensional materials such as functionalized grapheme or MoS2are emerging as novel electrocatalysts for the *** review covers various aspects towards the design of future ORR electrocatalysts,including the catalytic performance,stability,durability and *** novel electrocatalysts even surpass commercial Pt/C systems,demonstrating their potential to be alternatives in industrial *** the encouraging progress,challenges,which are also described,remain to be overcome before the real‐world application of novel ORR electrocatalysts.

关键词： Oxygen reduction reaction Electrocatalyst Nanomaterial Molecular electrocatalyt Two‐dimensional material

Application study of a correction method for a spacecraft thermal model with a Monte-Carlo hybrid algorithm

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Chinese Science Bulletin 2011年第13期56卷 1407-1412页

作者： cheng wenlong LIU Na LI Zhi ZHONG Qi WANG AiMing ZHANG ZhiMin HE ZongBo Department of Thermal Science and Energy Engineering University of Science and Technology of China Hefei 230027 China Research and Development Center China Academy of Space Technology Beijing 100094 China Beijing Institute of Spacecraft System Engineering Chinese Academy of Space Technology Beijing 100094 China

The correction of a thermal model for a thermally controlled satellite in ground test conditions is studied using a Monte Carlo hybrid ***,the global and local parameters are summarized according to sensitivity analyses on uncertain parameters,and then the model correction is treated as a parameter optimization problem to be solved with a hybrid ***,the correction of the thermal model is completed using a layered correction *** sensitivity analysis showed that the effective emissivities across the multi-layer insulation (MLI) and the emissivities of the thermal control coating are global parameters,while the contact heat transfer coefficients are local *** correction,the deviations between the calculated and test values were all within ± 3 ℃.The final results prove that the method in this study is superior to traditional methods and satisfies the requirements for thermal model correction.

关键词：校正方法混合算法热模型蒙特卡洛航天器敏感性分析应用模型修正

Hydrodynamic Characteristics of Undular Tidal Bores in the Qiantang River Based on Field Observations

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China Ocean Engineering 2024年第3期38卷 505-518页

作者： ZHANG Shu-yu PAN Cun-hong ZHANG Shen-yang LI Ruo-hua cheng wenlong XIE Dong-feng Zhejiang Tongji Vocational College of Science and Technology Hangzhou 311231China Zhejiang Institute of Hydraulics and Estuary Hangzhou 310020China

Understanding the undular tidal bores in the Qiantang River is essential for effective river management and *** breaking tidal bores have been studied extensively, reports on undular tidal bores in the Qiantang Riverremain limited. Furthermore, observed data on undular tidal bores fulfilling the requirements of short measurementtime intervals, and spring, medium, and neap tide coverage, and providing detailed data for the global vertical stratificationof flow velocity are quite limited. Based on field observations at Qige in the Qiantang estuary, we analyzedthe characteristics of undular tidal bores. The results showed that the flooding amplitude (a) of the first wave isalways larger than its ebbing amplitude (b). Moreover, the vertical distribution of the maximum flood velocity exhibitesthree shapes, influenced by the tidal range, while that of the maximum ebb velocity exhibites a single shape. Duringthe initial phase of the flood tide in the spring and medium tides, the upper water body experiences multiple oscillatingchanges along the flow direction, corresponding to the alternating process of the crest and trough of the tide levelupon the arrival of the tidal bore. The tidal range is a crucial parameter in tidal bore hydrodynamics. By establishingthe relationship between hydrodynamic parameters and tidal range, other hydrodynamic parameters, such as the tidalbore height, maximum flood depth–averaged velocity, maximum flood stratified velocity at the measurement points,and duration of the flood tide current, can be effectively predicted, thereby providing an important reference for rivermanagement and maintenance.

关键词： tidal bores Qiantang Estuary tidal bore height tidal bore velocity propagation speed

Self-Assembled Plasmonic Pyramids from Anisotropic Nanoparticles for High-Efficient SERS

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Journal of Analysis and Testing 2017年第4期1卷 335-343页

作者： Wenjuan Yang Kae Jye Si Pengzhen Guo Dashen Dong Debabrata Sikdar Malin Premaratne wenlong cheng Department of Chemical Engineering Faculty of EngineeringMonash UniversityClaytonVIC 3800Australia The Melbourne Centre for Nanofabrication 151 Wellington RoadClaytonVIC 3168Australia Advanced Computing and Simulation Laboratory(AvL) Department of Electrical and Computer Systems EngineeringFaculty of EngineeringMonash UniversityClaytonVIC 3800Australia Department of Chemistry Faculty of Natural SciencesImperial College LondonExhibition RoadSouth KensingtonLondon SW72AZUK

Surface-enhanced Raman scattering(SERS)substrates play important roles for the enhancement of inelastic scattering *** substrates such as roughened electrodes and colloidal aggregates suffer from well-known signal reproducibility issues,whereas for current dominant two-dimensional planar systems,the hot spot distributions are limited by the zero-,one-or two-dimensional *** introduction of a three-dimensional(3D)system such as a pyramid geometry breaks the limitation of a single Cartesian SERS-active area and extends it into the z-direction,with the tip potentially offering additional benefits of strong field enhancement and high ***,current 3D pyramidal designs are restricted to film deposition on prepared pyramid templates or self-assembly in pyramidal molds with spherical building blocks,hence limiting their SERS ***,we report on the fabrication of a new class of low cost and well-defined plasmonic nanoparticle pyramid arrays from different anisotropic shaped nanoparticles using combined top-down lithography and bottom-up self-assembly *** pyramids exhibit novel optical scattering properties that can be exploited for the design of reproducible and sensitive SERS *** SERS intensity was found to decrease drastically in accordance with a power law function as the focal planes move from the apex of the pyramid structure towards the *** comparison to sphere-based building blocks,pyramids assembled from anisotropic rhombic dodecahedral gold nanocrystals with numerous sharp tips exhibited the strongest SERS *** Abstract Macroscale pyramidal array films with plasmonic tunability as a new class of SERS substrate for sensitive detection of chemicals.

关键词： Self-assembly Pyramid Plasmonics Shape anisotropy Surface-enhanced Raman scattering

Single-cell transcriptome atlas reveals spatiotemporal developmental trajectories in the basal roots of moso bamboo (Phyllostachys edulis)

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Horticulture Research 2023年第8期10卷 59-71页

作者： Zhanchao cheng Changhong Mu Xiangyu Li wenlong cheng Miaomiao Cai Chongyang Wu Jutang Jiang Hui Fang Yucong Bai Huifang Zheng Ruiman Geng Junlei Xu Yali Xie Yuping Dou Juan Li Shaohua Mu Jian Gao Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo&Rattan Science and Technology International Center for Bamboo and RattanBeijing 100102China

Roots are essential for plant growth and *** is a large Poaceae perennial with 1642 species ***,little is known about the transcriptional atlas that underpins root cell-type ***,we set up a modified protocol for protoplast preparation and report single-cell transcriptomes of 14279 filtered single cells derived from the basal root tips of moso *** identified four cell types and defined new cell-type-specific marker genes for the basal *** reconstructed the developmental trajectories of the root cap,epidermis,and ground tissues and elucidated critical factors regulating cell fate *** to in situ hybridization and pseudotime trajectory analysis,the root cap and epidermis originated from a common initial cell lineage,revealing the particularity of bamboo basal root *** further identified key regulatory factors for the differentiation of these cells and indicated divergent root developmental pathways between moso bamboo and ***,PheWOX13a and PheWOX13b ectopically expressed in Arabidopsis inhibited primary root and lateral root growth and regulated the growth and development of the root cap,which was different from WOX13 orthologs in *** together,our results offer an important resource for investigating the mechanism of root cell differentiation and root system architecture in perennial woody species of Bambusoideae.

关键词： inhibited roots bamboo

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高孔隙率泡沫金属相变材料储能、传热特性

太阳能学报 2007年第7期28卷 739-744页

作者：程文龙韦文静中国科学技术大学热科学和能源工程系合肥230027

以高孔隙率泡沫金属材料作为骨架制备而成的新型复合相变储能材料的导热系数将大大高于相变材料本身的导热系数,在储能过程中具有更好的传热效果。给出了较通用的高孔隙率泡沫金属材料等效导热系数的估算公式,并利用准稳态方法建立了复... 详细信息

以高孔隙率泡沫金属材料作为骨架制备而成的新型复合相变储能材料的导热系数将大大高于相变材料本身的导热系数,在储能过程中具有更好的传热效果。给出了较通用的高孔隙率泡沫金属材料等效导热系数的估算公式,并利用准稳态方法建立了复合相变材料在凝固过程的数值模型,对其凝固过程的传热特性进行了理论分析。以铝—石蜡和铜—石蜡复合材料作为研究对象。分析表明,采用复合储能材料可以使得其传热性能得到很大提高,但是也会使复合材料的储能能力有所降低。提出了一种平衡储能能力和传热性能的方法,当泡沫金属处于平衡孔隙率时,在传热性能得到极大提高的同时也使得其储能能力降低不多。同时,分析得到了外部换热环境对储能能力、传热性能以及平衡孔隙率的影响,即较大的对流换热时,若要取得适当的储能能力和传热性能,则需要较小的孔隙率。

关键词：泡沫金属多孔介质相变准稳态法热阻

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油井传热瞬态导热函数的高精度近似解

化工学报 2013年第5期64卷 1561-1565页

作者：程文龙年永乐中国科学技术大学热科学和能源工程系安徽合肥230027

瞬态导热函数是注蒸汽油井热采过程中分析井筒传热的关键函数。目前常用的的瞬态导热函数以及相应的近似解都忽略井筒热容等参数的影响,但在注汽时间较短时井筒热容对传热影响很明显,因此在注蒸汽初期误差较大。新的瞬态导热函数近似解... 详细信息

瞬态导热函数是注蒸汽油井热采过程中分析井筒传热的关键函数。目前常用的的瞬态导热函数以及相应的近似解都忽略井筒热容等参数的影响,但在注汽时间较短时井筒热容对传热影响很明显,因此在注蒸汽初期误差较大。新的瞬态导热函数近似解是在考虑了井筒热容的瞬态导热函数的基础上建立的,可以更好地适用于注蒸汽初期。研究结果表明,新的瞬态导热函数近似解形式简单、应用方便,比传统的近似解具有更广的适用性和更高的计算精度,因此有较好的工程实用性。

关键词：井筒传热瞬态导热函数井筒热容近似解