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Journal of Hydrodynamics 1991年第2期3卷 1-4页

作者： zhai, da-xi Zhao, Han-zhong Huazhong Univ of Science and Technology Wuhan China

In this paper, an iteration method is presented to calculate the steady noseparation flow past a circular cylinder with brokenline-shaped velocity profile. At each iteration step, the streamlines of the last step are considered as equivorticity lines to determine the new flow field. The iterative process is stopped when certain convergence criterion is reached. Several examples are given which show the effectiveness of the method.

关键词： Fluid Mechanics Hydrodynamics Mathematical Techniques Piecewise Linear Techniques Stream Flow

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外流问题的外边界条件设计

水动力学研究与进展（A辑） 2002年第6期17卷 709-719页

作者：李勇李向群翟大熙北京大学力学与工程科学系北京100087

粘性外流计算原则上要求在无限大的外空间进行 ,巨大的计算区要求巨大的计算机资源。本文利用一般绕流问题在远区流动尺度大 ,因而雷诺数大的特点对远外处的流动近似地用位势流代替 ,从而在较小的流体边界条件上建立了“开边界条件” ,... 详细信息

粘性外流计算原则上要求在无限大的外空间进行 ,巨大的计算区要求巨大的计算机资源。本文利用一般绕流问题在远区流动尺度大 ,因而雷诺数大的特点对远外处的流动近似地用位势流代替 ,从而在较小的流体边界条件上建立了“开边界条件” ,由此大大缩小了计算工作量。

关键词： N-S方程开边界条件势流理论

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复杂异相射流计算收敛的一个办法

水动力学研究与进展（A辑） 2004年第z1期19卷 833-837页

作者：翟大熙李向群安亦然北京大学北京100871

　水下高速可压缩气体射流的两相流计算不易收敛,本文提出按水的密度设计一种理想气体,然后与燃气一起按两相气体混合流进行计算取得成功。这一办法对一相基本静止的情况时实用的。

关键词：射流两相流水下推进

Defect Engineering with Rational Dopants Modulation for High-Temperature Energy Harvesting in Lead-Free Piezoceramics

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NANO-MICRO LETTERS 2025年第1期17卷 1-15页

作者： xi, Kaibiao Guo, Jianzhe Zheng, Mupeng Zhu, Mankang Hou, Yudong Beijing Univ Technol Coll Mat Sci & Engn Key Lab Adv Funct Mat Minist Educ Beijing 100124 Peoples R China

High temperature piezoelectric energy harvester (HT-PEH) is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors. However, simultaneously excellent performances, including high figure of merit (FOM), insulation resistivity (rho) and depolarization temperature (T-d) are indispensable but hard to achieve in lead-free piezoceramics, especially operating at 250 degrees C has not been reported before. Herein, well-balanced performances are achieved in BiFeO3-BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping. Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization, regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole, comprehensive excellent electrical performances (T-d = 340 degrees C, rho(250) (degrees C) > 10(7) Omega cm and FOM2(50 degrees C) = 4905 x 10(-15 )m(2) N-1) are realized at the solid solubility limit of manganese ions. The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250 degrees C with high energy conversion efficiency (eta = 11.43%). These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements, paving a new way in developing self-powered wireless sensors working in HT environments.

关键词： Lead-free piezoceramic Defect engineering Dopants modulation High-temperature Piezoelectric energy harvester

Influence of misting system on the thermal environment and thermal comfort of seated people in semi-outdoor space in xi’an,China

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Frontiers of Architectural Research 2024年第3期13卷 668-681页

作者： Xu xie Zhen Sun xi Zhu Shengkai Zhao Zun Wang Yongchao zhai College of Architecture Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Green Building Xi’an University of Architecture and TechnologyXi’an 710055China

In summer,factors such as solar radiation could make semi-outdoor spaces uncomfortable,and the use of misting systems for evaporative cooling is a low-energy improvement *** investigate the impact of misting system on the thermal environment and thermal comfort of seated people improvement,a field study was conducted at a semi-outdoor cafeteria in xi’*** results indicated that the misting system was capable of reducing the ambient air temperature by 2.4-4.9℃and increasing the relative humidity by 17.1%-17.8%.Participants in misting condition reported lower thermal sensation and higher thermal acceptability,thermal preference,humidity sensation,humidity preference and humidity *** no misting condition,the upper SET*limit acceptable to 80%of the population was 28.5℃.However,in the misting condition,the acceptable percentage of participants in each SET)interval was more than 90%.When SET)was 22.1-23.7℃,the improvement in human thermal comfort through misting system was not *** SET)was 23.7-28.5℃,the misting system significantly improve human thermal ***,two control temperature thresholds of the misting system were provided according to the relationship between 80%,the maximum(89.3%)acceptable percentage and the air temperature,which were 30.1℃and 26.5℃,respectively.

关键词： Misting system Thermal environment Thermal response Acceptable temperature Control strategy

The Effect of the Gap Ratio on the Flow and Heat Transfer over a Bluff Body in Near-Wall Conditions

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Fluid Dynamics & Materials Processing 2022年第1期18卷 109-130页

作者： Shaohua zhai Guannan xi School of Mechanical Engineering Nantong UniversityNantong226019China School of Mechanical Engineering Nantong Institute of TechnologyNantong226019China

In order to study the effect of different gap ratios on the thermofluid-dynamic field around a bluff body located in proximity to a heated wall,a series of experiments and numerical simulations have been *** former were carried out using an open circulating water tank experimental platform and a single cylinder and square column as geometrical models(their characteristic length being D).The latter were based on the well-known SIMPLE algorithm for incompressible *** results show that the gap ratio is an important factor affecting the wake characteristics of near-wall bluff *** the gap ratio is small,the influence of the wall on the bluff body wake is *** an increase in the gap extension,periodic vortex shedding is enabled and heat transfer is strengthened accordingly;in addition,the vortex shedding period is larger for the square *** square column displays hysteresis compared with the cylinder at the same gap ratio(the critical gap ratio of cylinder is 0.2~0.4,while that of square column is 0.40.6).

关键词： Transition flow gap ratio near-wall flow characteristic enhanced heat transfer

Type Synthesis of Walking Robot Legs

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Chinese Journal of Mechanical Engineering 2018年第1期31卷 53-65页

作者： da xi Feng Gao State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

Walking robots use leg structures to overcome obstacles or move on complicated terrains. Most robots of current researches are equipped with legs of simple structure. The specific design method of walking robot legs is seldom studied. Based on the generalized-function(GF) set theory, a systematic type synthesis process of designing robot legs is introduced. The specific mobility of robot legs is analyzed to obtain two main leg types as the goal of *** synthesis problem is decomposed into two stages, actuation and constraint synthesis by name,corresponding to the combinatorics results of linear Diophantine equations. Additional restrictions are discussed to narrow the search range to propose practical limb expressions and kinematic-pair designs. Finally, all the fifty-one leg structures of four subtypes are carried out, some of which are chosen to make up robot prototypes, demonstrating the validity of the method. This paper proposed a novel type synthesis methodology, which could be used to systematically design various practical robot legs and the derived robots.

关键词： Type synthesis Robot leg GF set Number synthesis Linear Diophantine equation

Mechanistic insight into the synergy between nickel single atoms and nanoparticles on N-doped carbon for electroreduction of CO2

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Journal of Energy Chemistry 2025年第1期100卷 327-336页

作者： Mingdong Sun Wenwen Guan Cailing Chen Chao Wu xiaoling Liu Biao Meng Tao Chen Yu Han Jun Wang Shibo xi Yu Zhou State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University Advanced Membranes and Porous Materials Center Physical Sciences and Engineering Division King Abdullah University of Science and Technology Institute of Sustainability for Chemicals Energy and Environment A*STAR (Agency for Science Technology and Research) College of Materials Science and Engineering Sichuan University

The synergy of single atoms （SAs） and nanoparticles （NPs） has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction （CO2RR）;however,the rationalization of the SAs/NPs proportion remains one challenge for the catalyst ***,a Ni2+-loaded porous poly（ionic liquids）(PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer,1-allyl-3-vinylimidazolium chloride,was pyrolyzed to prepare the Ni,N co-doped carbon materials,in which the proportion of Ni SAs and NPs could be facilely modulated by controlling the annealing *** catalyst Ni-NC-1000 with a moderate proportion of Ni SAs and NPs exhibited high efficiency in the electrocatalytic conversion of CO2into *** Ni K-edge X-ray absorption near-edge structure （XANES） spectra and theoretical calculations were conducted to gain insight into the synergy of Ni SAs and *** charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni SAs resulted in the electron-enriched Ni SAs active *** the electroreduction of CO2,the coexistence of Ni SAs and NPs strengthened the CO2activation and the affinity towards the key intermediate of*COOH,lowering the free energy for the potential-determining*CO2→*COOH step,and therefore promoted the catalysis efficiency.

关键词： Single atom catalyst Synergy effect Carbon catalyst Electrocatalysis

Deaggregation of long chain alkyl β-naphthoic acid ester with β-CD and α-CD:A mimic way to remove excessive fat from fatty liver

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Chinese Chemical Letters 2008年第6期19卷 720-724页

作者： Chun xi zhai Hai Ning Gu da Yong Sang Juan Tian Qi Zhong Zhou Department of Chemistry Zhejiang University Hangzhou 310027 China

The deaggregating ability of β-CD and α-CD against the aggregated n-hexadecyl β-naphthoate （A16） and n-dodecyl β-naphthoate （A12） depended not only on the aggregating tendency of A16 and A12 but also on the initial concentration of the aggregated A16 or A12. The inclusive ability of β-CD with the substrates is greater than that of α-CD under hydrophobiclipophilic interaction.

关键词： Deaggregation Aggregation Coaggregation Critical aggregating concentration

FUBP3 mediates the amyloid-β-induced neuronal NLRP3 expression

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Neural Regeneration Research 2025年第7期20卷 2068-2083页

作者： Jing Yao Yuan Li xi Liu Wenping Liang Yu Li Liyong Wu Zhe Wang Weihong Song The National Clinical Research Center for Geriatric Disease Xuanwu HospitalCapital Medical UniversityBeijingChina Department of Neurology The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan ProvinceChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina Department of Pediatrics The Second Affiliated Hospital and Yuying Children’s HospitalKey Laboratory of Alzheimer’s Disease of Zhejiang ProvinceInstitute of AgingWenzhou Medical UniversityWenzhouZhejiang ProvinceChina Oujiang Laboratory(Zhejiang Laboratory for Regenerative Medicine Visionand Brain Health)WenzhouZhejiang ProvinceChina

Alzheimer's disease is characterized by deposition of amyloid-β,which forms extracellular neuritic plaques,and accumulation of hyperphosphorylated tau,which aggregates to form intraneuronal neurofibrillary tangles,in the *** NLRP3 inflammasome may play a role in the transition from amyloid-βdeposition to tau phosphorylation and *** NLRP3 is primarily found in brain microglia,and tau is predominantly located in neurons,it has been suggested that NLRP3 expressed by microglia indirectly triggers tau phosphorylation by upregulating the expression of pro-inflammatory ***,we found that neurons also express NLRP3 in vitro and in vivo,and that neuronal NLRP3 regulates tau *** biochemical methods,we mapped the minimal NLRP3 promoter and identified FUBP3 as a transcription factor regulating NLRP3 expression in *** primary neurons and the neuroblastoma cell line Neuro2A,FUBP3 is required for endogenous NLRP3 expression and tau phosphorylation only when amyloid-βis *** the brains of aged wild-type mice and a mouse model of Alzheimer's disease,FUBP3 expression was markedly increased in cortical *** analysis suggested that FUBP3 plays a role in neuron-mediated immune *** also found that FUBP3 trimmed the 5′end of DNA fragments that it bound,implying that FUBP3 functions in stress-induced *** findings suggest that neuronal NLRP3 may be more directly involved in the amyloid-β-to–phospho-tau transition than microglial NLRP3,and that amyloid-βfundamentally alters the regulatory mechanism of NLRP3 expression in *** that FUBP3 was only expressed at low levels in young wild-type mice and was strongly upregulated in the brains of aged mice and Alzheimer's disease mice,FUBP3 could be a safe therapeutic target for preventing Alzheimer's disease progression.

关键词： 5′end trimming Alzheimer's disease amyloid-beta amyloid-β-dependent transcription FUBP3 inflammasome inflammation neuron NLRP3 tau transcription factor