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CFD analysis of a transfer matrix of exhaust muffler with mean flow and prediction of exhaust noise

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第9期13卷 709-716页

作者： Lian-yun LIU zhi-yong hao Chi LIU Department of Energy Engineering Zhejiang UniversityHangzhou 310027China

A multi-dimensional computational fluid dynamics(CFD) approach was proposed in this study aiming to calculate the transfer matrix of an engine exhaust muffler in the conditions with and without mean *** CFD model of the muffler with absorptive material defined as porous zone was calibrated with the measured noise reduction without mean flow,and was further employed to study the effect of the mean flow on the acoustic performance of the ***,the exhaust acoustical source was derived from the calculated transfer matrices of six different additional acoustic loads obtained by the proposed CFD approach as well as the measured tail noise based on a multiload least squares ***,the exhaust noise was predicted based on Thevenin's *** proposed CFD approach was suggested to be able to predict the acoustic performance of a complex muffler considering mean flow(without and with mean flow) and heat transfer,and provide reasonable results of the exhaust noise.

关键词： Computational fluid dynamics (CFD) Transfer matrix Mean flow Acoustical source Exhaust noise

Experimental validation of sound quality simulation and optimization of a four-cylinder diesel engine

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第5期14卷 341-352页

作者： Jie MAO zhi-yong hao Kang ZHENG Guo-xi JING Department of Energy Engineering Zhejiang University

A novel sound quality simulation approach was proposed to optimize the acoustic performance of a four-cylinder diesel *** element analysis,single-input and multiple-output technology,flexible multi-body dynamics,and boundary element codes were used to acquire the hexahedron-element model,experimental modal frequencies,vibration velocities,and structurally radiated noise of the block,*** simulated modal frequencies and vibration velocities agreed well with the experimental data,which validated the finite-element *** acoustic response showed that considerable acoustic power levels existed in 1500-1900 Hz and 2300-2800 Hz as the main frequency ranges to optimize the block ***,the optimal block is determined in accordance with the novel approach,which reduces the overall value,high-frequency amplitudes,and peak values of acoustic power;thus,the loudness,sharpness,and roughness decline to make the sound quieter,lower-pitched,and smoother,***,the optimal block was cast and *** results reveal that the sound quality of the optimal-block engine is substantially improved as numerically expected,which verifies the effectiveness of the research approach.

关键词： Diesel engine Flexible multi-body dynamics Sound quality simulation Block optimization Sound quality improvement

Preparation of thiophilic paramagnetic adsorbent for separation of antibodies

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Chinese Chemical Letters 2008年第12期19卷 1495-1498页

作者： Ming Qin Chen zhi yong Lin hao Qian College of Material Science and Engineering Huaqiao University Quanzhou 362021 China

The micron-sized microspheres with superparamagnetic property were synthesized with vinyl acetate and divinylbenzene by microsuspension polymerization. After the complete alcoholysis, these hydroxyl-functionalized microspheres were activated by divinylfone and modified with mercaptoethanol to prepare the thiophilic magnetic adsorbent, which was used to specifically isolate immunoglobulin G （IgG） from human serum. This thiophilic magnetic adsorbent performed an evident salt-dependent adsorption behavior for IgG. Due to their salt-promoted adsorption towards IgG under high salt concentration, the absorbed antibodies could be extracted in low salt concentration with high purity.

关键词： Superparamagnetic Thiophilic Microsuspension Immunoglobulin G Isolation

Simulation of α-Al grain formation in high vacuum die-casting Al-Si-Mg alloys with multi-component quantitative cellular automaton method

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China Foundry 2022年第2期19卷 99-108页

作者： yong-zhi hao Hai-dong Zhao Xu Shen Xue-ling Wang Hui-ting Zheng National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

Al-Si-Mg alloys are the most commonly used material in high vacuum die-casting(HVDC),in which the morphology and distribution ofα-Al grains have important effect on mechanical properties.A multi-component quantitative cellular automaton(CA)model was developed to simulate the microstructure and microsegregation of HVDC Al-Si-Mg alloys with different Si contents(7%and 10%)and cooling rates during *** grain number and average grain size with electron backscatter diffraction(EBSD)analysis were used to verify the *** relationship between grain size and nucleation order as well as nuclei density was investigated and *** is found that the growth of grains will be restrained in the location with higher nuclei *** influence of composition and cooling rate on the solute transport reveals that for AlSi7Mg0.3 alloy the concentration of solute Mg in liquid is higher at the beginning of eutectic *** comparison between simulation and experiment results shows that externally solidified crystals(ESCs)have a significant effect for samples with high cooling rate and narrow solidification interval.

关键词： Al-Si-Mg alloys high vacuum die-casting cellular automaton α-Al grains external solidification crystals

Sound quality evaluation of high-speed train interior noise by adaptive Moore loudness algorithm

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第9期18卷 690-703页

作者： Le LUO, Xu ZHENG zhi-yong hao Wen-qiang DAI Wen-ying YANG Department of Energy Engineering Zhejiang University Hangzhou 310027 China

An online experiment to acquire the interior noise of a China Railways High-speed （CRH） train showed that it wasmainly composed of middle-low frequency components and could not be described properly by linear or A-weighted soundpressure level （SPL）. Thus, the appropriate way to evaluate the high-speed train interior noise is to use sound quality parameters,and the most important is loudness. To overcome the disadvantages of the existing loudness algorithms, a novel signal-adaptiveMoore loudness algorithm （AMLA） based on the equivalent rectangular bandwidth （ERB） spectrum was introduced. The valida-tion reveals that AMLA can obtain higher accuracy and efficiency, and the simulated dark red noise conforms best to thehigh-speed train interior noise by loudness and auditory assessment. The main loudness component of the interior noise is below27.6 ERB rate （erbr）, and the sound quality of the interior noise is relatively stable between 300-350 km/h. The specific loudnesscomponents among 12-15 erbr stay invariable throughout the acceleration or deceleration process while components among20-27 erbr are evidently speed related. The unusual random noise is effectively identified, which indicates that AMLA is anappropriate method for sound quality assessment of the high-speed train under both steady and transient conditions.

关键词： High-speed train Sound quality evaluation Equivalent rectangular bandwidth (ERB) spectrum Adaptive Mooreloudness algorithm (AMLA) Unusual random noise

Transurethral seminal vesiculoscopy in the diagnosis and treatment of persistent or recurrent hemospermia： a single- institution experience

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Asian Journal of Andrology 2009年第5期11卷 566-570,I0002页

作者： zhi-yong Liu Ying-hao Sun Chuan-Liang Xu Jian-Guo Hou Xu Gao Xin Lu Hua-Mao Ye Lin-Hui Wang Xiao-Feng Gao Shanghai Changhai Hospital the Second Military Medical University Shanghai 200433 China

The diagnosis and treatment of hemospermia presents significant difficulty, especially if it persists or recurs. In this retrospective study, we assessed whether transurethral seminal vesiculoscopy is feasible and effective in the diagnosis and treatment of hemospermia. To address this complex condition, we report our experience in a population of patients treated with transurethral seminal vesiculoscopy. From February 2006 to July 2008, 72 hemospermic patients underwent transurethral seminal vesiculoscopy examination and treatment at our urology center. Transurethral seminal vesiculoscopy was performed by a 7-F or 8-F rigid ureteroscope. The endoscopic procedure was conducted through the normal anatomic route of the seminal tracts. In this series, the mean follow-up period was 21.7 months. Definite diagnosis was made for 93.1% patients, and 94.4% patients were cured or showed a decrease in their symptoms. Postoperative complications were not observed in the study. Our study proves that transurethral seminal vesiculoscopy is effective in the diagnosis and treatment of hemospermia with minimal complication.

关键词： diagnosis hemospermia transurethral seminal vesiculoscopy treatment

STRUCTURE OF NOVEL DICOPPER（Ⅱ） COMPLEX Cu2 （oxpn）（NCS）2 （H2O）(oxpn=N,N'-bis（3-aminopropyl） oxamido)

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Chinese Journal of Structural Chemistry 1991年第2期 143-146页

作者： Yao Xin-Kan Wang Hong-GenCentral Laboratory, Nankai University, Tianjin 300071Liao Dai-Zheng Zhang zhi-yong hao Song-Qi Jiang Zong-Hui Wang Geng-LinDepartment of Chemistry, Nankai University,Tian jin 300071

C10H10Cu2N6O4S2,Mr = 475. 41,monoclinic,space group P2/c,a = 8. 531 (2),b= 6. 870(1) ,c= 14. 463(2) A ,β=93. 84 (2), V= 845. 7 A3,Z=2,D = 1. 866 g·cm-3,μ=27. 799cm-1,F(000) = 484,R=0. 071. The molecules possesse basically a planar structure ,with the two aquamolecules displaced 2. 75 A to opposite sides of this plane and being at the apexpositions of the square pyramidal coordination of the two Cu atoms, respectively, the two carbonyls of the oxamide show the "trans-form".

关键词： Cu oxpn H2O oxpn=N,N aminopropyl oxamido bis NCS COMPLEX Cu2

Deciphering the role of ultra-low-loaded rhodium in NiFe-MIL-53 for superior oxygen evolution reaction

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Journal of Energy Chemistry 2025年第1期100卷 77-86页

作者： Jinzhi Jia Jinhua Zhang Kailu Guo Lanyue Zhang Gening Du hao You Junfeng Huang Mudong Tu Hua Li yong Peng Wei Dou Cailing Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering School of Materials and Energy Lanzhou University College of Chemistry and Chemical Engineering Luoyang Normal University

Designing highly active and stable electrocatalysts of oxygen evolution reaction （OER） is one of the crucial *** this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium（Rh@NiFe-MIL-53）,is successfully prepared via the hydrothermal ***-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active *** importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe（OH）2after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@***,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center （εd）,accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining ***,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity （240 mV） with a small Tafel slope of 48.2 mV dec-1and long-term durability (over1270 h at 10 m A cm-2and 110 h at 200 mA cm-2).This work presents a new perspective on designing highly efficient OER electrocatalysts.

关键词： NiFe-MIL-53 Rh Electrochemical reconstruction Catalytic mechanism Oxygen evolution reaction

全血和滤纸干血AS-PCR体系的缓冲液研究

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中国新药杂志 2016年第24期25卷 2876-2880页

作者：侯志勇曾皓月杨会勇林俊生王立强解放军211医院哈尔滨150080 华侨大学生物医学学院泉州362021

目的:研制一种以全血和滤纸干血为模板的等位基因特异性PCR(allele-specific polymerase chain reaction,AS-PCR)体系的缓冲液。方法:采用血样直接作为模板,通过引入错配碱基对AS-PCR的特异性进行改进,研制一种新型缓冲液HPEC[p H 9.5,M... 详细信息

目的:研制一种以全血和滤纸干血为模板的等位基因特异性PCR(allele-specific polymerase chain reaction,AS-PCR)体系的缓冲液。方法:采用血样直接作为模板,通过引入错配碱基对AS-PCR的特异性进行改进,研制一种新型缓冲液HPEC[p H 9.5,Mg2+3.5 mmol·L^(-1),海藻糖2.5μmol·L^(-1),(NH4)2SO49.6mmol·L^(-1),Tween-20 0.01%],对包含单核苷酸多态性位点(single nucleotide polymorphisms,SNPs)的目的片段进行扩增。结果:该方法成功地实现了以血样和滤纸干血为模板的AS-PCR基因分型。结论:此缓冲液省去了扩增前基因组的提取和纯化,简化了操作过程,降低DNA污染机会和检测技术的复杂性。

关键词：缓冲液全血扩增基因诊断