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Engineering the Surface Structure of Functional Nanocrystalline Materials and their Corresponding Applications

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Engineering the Surface Structure of Functional Nanocrystall...

FAST IMPLEMENTATION OF ORTHOGONAL EMPIRICAL MODE DECOMPOSITION AND ITS APPLIGA-TION INTO HARMONIC DETECTION

第二届海峡两岸功能材料科技与产业峰会（2015）

作者： qin Kuang yaqi Jiang Zhiyuan Jiang Zhaoxiong Xie State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy MaterialsCollege of Chemistry and Chemical EngineeringXiamen University

The physical and chemical properties of nanocrystalline materials depend on the surface *** with high-energy facets exposed usually show high physical and chemical activities,due to abundant unsaturated coordination atoms and atomic steps and ***,in order to minimize the surface energy of the crystals,the high-energy facets quickly disappeared in the crystal growth ***,controllable synthesis of the nanocrystals exposed with high-energy facets is still a challenging topic.

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 93-98页

作者： qin Yi qin Shuren MAO Yongfang College of Mechanical Engineering Chongqing University Chongqing 400044 China

Since the empirical mode decomposition （EMD） lacks strict orthogonality, the method of orthogonal empirical mode decomposition （OEMD） is innovationally proposed. The primary thought of this method is to obtain the intrinsic mode function （IMF） and the residual function by auto-adaptive band-pass filtering. OEMD is proved to preserve strict orthogonality and completeness theoretically, and the orthogonal basis function of OEMD is generated, then an algorithm to implement OEMD fast, IMF binary searching algorithm is built based on the point that the analytical band-pass filtering preserves perfect band-pass feature in the frequency domain. The application into harmonic detection shows that OEMD successfully conquers mode aliasing, avoids the occurrence of false mode, and is featured by fast computing speed. Furthermore, it can achieve harmonic detection accurately combined with the least square method.

关键词： Empirical mode decomposition Orthogonal empirical mode decomposition Analytic band-pass filtering Binary searching Harmonic detection

One-pot calcination synthesis of Cd_(0.5)Zn_(0.5)S/g-C_(3)N_(4) photocatalyst with a step-scheme heterojunction structure

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Journal of Materials Science & Technology 2020年第21期56卷 206-215页

作者： Dongran qin Yang Xia qin Li Chao Yang Yanmin qin Kangle Lv Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&Hubei Key Laboratory of Catalysis and Materials Science South-Central University for NationalitiesWuhan 430074China

Cd_(0.5)Zn_(0.5)S/g-C_(3)N_(4)(CZS/CN)step-like heterojunction composites were facilely synthesized by annealing a sandwich of cadmium-zinc-thiourea precursors in one *** types of the used raw materials and the preparation procedure were simplified as much as possible in this *** obtained hybrid exhibited enlarged specific surface area and higher separation/transfer efficiency of charge carriers compared to pure Cd_(0.5)Zn_(0.5)S and g–C_(3)N_(4),thus exhibited much enhanced photocatalytic efficiency for dye degradation under visible-light *** interfacial charge-transfer mechanism of the formed step-scheme(Sscheme)heterojunction between Cd_(0.5)Zn_(0.5)S and g–C_(3)N_(4) were carefully investigated and *** work could widen the application prospect of the Cd_(x)Zn_(1-x)S/g-C_(3)N_(4) composite and provide new ideas to the design and fabrication of novel heterojunctions with robust photocatalytic performance.

关键词： Cd_(0.5)Zn_(0.5)S g-C_(3)N_(4) S-scheme heterojunction Photocatalysis Visible light

Demodulation Based on Harmonic Wavelet and Its Application into Rotary Machinery Fault Diagnosis

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Chinese Journal of Mechanical Engineering 2009年第3期22卷 419-425页

作者： MAO Yongfang qin Shuren qin Yi College of Automation Chongqing Univers#y Chongqing 400030 China

The harmonic wavelet transform（HWT） and its fast realization based on fast Fourier transform（FFT） are introduced. Its ability to maintain the same amplitude-frequency feature is revealed. A new method to construct the time-frequency（TF） spectrum of HWT is proposed, which makes the HWT TF spectrum able to correctly reflect the time-frequency-amplitude distribution of the signal. A new way to calculate the HWT coefficients is proposed. By zero padding the data taken out, the non-decimated coefficients of HWT are obtained. Theoretical analysis shows that the modulus of the coefficients obtained by the new calculation way and living at a certain scale are the envelope of the component in the corresponding frequency band. By taking the cross section of the new TF spectrum, the demodulation for the component at a certain frequency band can be realized. A comparison with the Hilbert demodulation combined with band-pass filtering is done, which indicates for multi-components, the method proposed here is more suitable since it realizes ideal band-pass filtering and avoids pass band selecting. In the end, it is applied to bearing and gearbox fault diagnosis, and the results reflect that it can effectively extract the fault features in the signal.

关键词： harmonic wavelet transform time-frequency spectrum demodulation rotary machinery fault diagnosis

New advances in coal structure model

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International Journal of Mining Science and Technology 2018年第4期28卷 541-559页

作者： qin Zhihong School of Chemical Engineering China University of Mining & Technology

Although human beings have come to understand and utilize coal for a very long history, no theoretical breakthrough in the study of coal structure has been made, which still needs continuous efforts of coal chemical workers. Based on the viewpoint of ‘vague/clear', the species classification and accurate analysis on coal were conducted by using the natural clustering all-component separation method. A more systematic and detailed coal embedded structure model theory which is suitable for coal of all ranks was developed from the previous one and a more complete theoretical system about the component and structure of coal was constructed. The whole establishment process of the theory was summarized and some of the main support data and analysis test results, including TEM, AFM, FTIR, GC/MS, MALDI/TOF/MS, DART/MSD, fractal analysis and so on were provided. The coal embedded structure theory fully considers both the identity and the particularity of all-rank coal, reflects the coal component and structure in the full range of coal rank, solves the systematic cognitive problem of coal component and structure on macro and micro level, and provides a valuable and meaningful theoretical approach for the coal processing and conversion technology.

关键词： Coal structure Embedded structure model Theory construction All group components separation Coal of all coal ranks

Energy flow characteristics of friction-induced nonlinear vibrations in a water-lubricated bearing-shaft coupled system

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Acta Mechanica Sinica 2021年第4期37卷 679-704,I0003页

作者： Li qin Hongling qin Jing Tang Xing Key Laboratory of Metallurgical Equipment and Control Technology School of Machinery&AutomationWuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory of Hydroelectric Machinery Design&Maintenance Three Gorges UniversityYichang 443002China Maritime Engineering Group CMEESchool of EngineeringFaculty of Engineering&Physical SciencesUniversity of SouthamptonSouthampton SO 171BJUK

Based on the energy flow theory of nonlinear dynamical system,the stabilities,bifurcations,possible periodical/chaotic motions of nonlinear water-lubricated bearing-shaft coupled systems are investigated in this *** is revealed that the energy flow characteristics around the equlibrium point of system behaving in the three types with different friction-para-mters.(a)Energy flow matrix has two negative and one positive energy flow factors,constructing an attractive local zero-energy flow surface,in which free vibrations by initial disturbances show damped modulated oscillations with the system tending its equlibrium state,while forced vibrations by external forces show stable oscillations,(b)Energy flow matrix has one negative and two positive energy flow factors,spaning a divergence local zero-energy flow surface,so that the both free and forced vibrations are divergence oscillations with the system being unstable,(c)Energy flow matrix has a zero-energy flow factor and two opposite factors,which constructes a local zero-energy flow surface dividing the local phase space into stable,unstable and central subspace,and the simulation shows friction self-induced unstable vibrations for both free and forced *** a set of friction parameters,the system behaves a periodical oscillation,where the bearing motion tends zero and the shaft motion reaches a stable limit circle in phase space with the instant energy flow tending a constant and the time averaged one tending *** simulations have not found any possible chaotic motions of the *** is discovered that the damping matrices of cases(a),(b)and(c)respectively have positive,negative and zero diagonal elements,resulting in the different dynamic behavour of system,which gives a giderline to design the water-lubricated bearing unit with expected performance by adjusting the friction parameters for applications.

关键词： Nonlinear friction-induced vibrations Nonlinear energy flows Nonlinear water-lubricated bearing-shaft systems Bifucation friction parameters Energy flow matrices Periodical oscilation

Homologous temperature of olivine: Implications for creep of the upper mantle and fabric transitions in olivine

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Science China Earth Sciences 2016年第6期59卷 1138-1156页

作者： WANG qin State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing University

The homologues temperature of a crystalline material is defined as T/Tm, where T is temperature and Tm is the melting （solidus） temperature in Kelvin. It has been widely used to compare the creep strength of crystalline materials. The melting temperature of olivine system, （Mg,Fe）2SiO4, decreases with increasing iron content and water content, and increases with confining pressure. At high pressure, phase transition will lead to a sharp change in the melting curve of olivine. After calibrating previous melting experiments on fayalite （Fe2SiO4）, the triple point of fayalite-Fe2SiO4 spinel-liquid is determined to be at 6.4 GPa and 1793 K. Using the generalized means, the solidus and liquidus of dry olivine are described as a function of iron content and pressure up to 6.4 GPa. The change of T/Tm of olivine with depth allows us to compare the strength of the up- per mantle with different thermal states and olivine composition. The transition from semi-brittle to ductile deformation in the upper mantle occurs at a depth where T/Tm of olivine equals 0.5. The lithospheric mantle beneath cratons shows much smaller T/Tm of olivine than orogens and extensional basins until the lithosphere-asthenosphere boundary where T/Tm 〉 0.66, suggesting a stronger lithosphere beneath cratons. In addition, T/Tm is used to analyze deformation experiments on olivine. The results indicate that the effect of water on fabric transitions in olivine is closely related with pressure. The hydrogen-weakening effect and its relationship with T/Tm of olivine need further investigation. Below 6.4 GPa （〈200 kin）, T/TIn of olivine controls the transition of dislocation glide from [100] slip to [001] slip. Under the strain rate of 10-12-10-15 s-1 and low stress in the upper mantle, the [100]（010） slip system （A-type fabric） becomes dominant when T/TIn〉 0.55-0.60. When T/Tm〈 0.55-0.60, [001] slip is easier and low T/Tm favors the operation of [001]（100） slip system （C-type fabric）. This is consistent with

关键词： Olivine Homologous temperature Lattice preferred orientation Water Seismic anisotropy Upper mantle

Fraction Distribution and Risk Assessment of Heavy Metals in Soils around the Mining Area in Zhijin

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Asian Agricultural Research 2015年第12期7卷 69-73,76页

作者： yaqi JIA Zhen YANG Dan GENG qin DENG Di WU Guizhou Provincial Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment Guizhou Normal University

The pollution characteristics of Cd,Cr,Cu,Zn,Ni and Hg in agricultural soil around coal mining area were studied. After longterm mining activity,the soil around mining area was polluted by 6 elements to different degrees. Especially for Cd,its concentration was 3. 2times that of the National Soil Environmental Quality Standard Ⅱ. The values suggest that the contamination degree from strong to weak in soil is in the order of Hg > Cu > Cr > Zn > Ni > Cd. BCR sequential extraction results show that the order of average percentage about weak acid soluble fraction( F1) is that Cd > Ni > Zn > Cu > Hg > Cr,the order of 6 heavy metals available fraction( F1 + F2 + F3) is that Cu( 56. 89) > Cd( 50. 95) > Ni( 41. 52) > Zn( 35. 06) > Hg( 23. 04) > Cr( 4. 88). The RAC results indicate that soils were in a moderate potential ecological risk by pollution of Cd,and at the same time,Cu,Zn,Ni,Hg should be noted.

关键词： Heavy metals Chemical form Geoaccumulation index Risk assessment code

基于4G技术的工程结构无线振动测试系统节点设计

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太原学院学报（自然科学版） 2025年第1期43卷 38-46页

作者：秦乐余沛信阳学院土木工程学院河南信阳464000

结构振动测试是大型土木工程结构健康监测的有效保障,传统振动测试存在布线困难、低频率信号拾取困难、通信速率底、易受到测试现场条件限制等问题。以4G技术为研究对象,提出了一种基于4G技术的工程结构无线振动测试系统节点设计方案,... 详细信息

结构振动测试是大型土木工程结构健康监测的有效保障,传统振动测试存在布线困难、低频率信号拾取困难、通信速率底、易受到测试现场条件限制等问题。以4G技术为研究对象,提出了一种基于4G技术的工程结构无线振动测试系统节点设计方案,通过节点工作原理介绍及各个模块的功能特性分析,研究了标准振动台性能对比测试和基于有线及无线的结构振动对比试验。结果表明:节点传感器的线性度误差为0.29%,且在短距离以及超远距离测试条件下,试验结构的各阶频率测试结果均与有线加速度传感器的测试结果一致,表明节点在测试精度和数据高速率传输等方面具有较大优势,解决了中远及超远距离中工程数据传输问题,具有一定的工程实用性,在土木工程健康监测和工程强震观测领域具有广泛的应用前景。

关键词： 4G通信技术无线振动测试节点灵敏度脉动自由衰减