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Facile synthesis of flake-like dihydrate zinc oxalate particles

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International Journal of Minerals,Metallurgy and Materials 2019年第2期26卷 234-240页

作者： Xing Chen Xin Liu kai huang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Global Energy Research Institute Future Science and Technology Park Beijing Key Lab of Green Recycling and Extraction of Metals University of Science and Technology Beijing

Monodispersed dihydrated zinc oxalate(ZnC_2O_4·2H_2O) particles with characteristic morphology were synthesized by aging a mixed solution of zinc nitrate(Zn(NO_3)_2) and sodium oxalate(Na_2C_2O_4) in the presence of a citrate ligand, with an average flat size of approximately 10–15 μm. The important parameters, including the solution pH values and the concentration of the zinc ions and citrate ligand, were investigated using a series of experiments. It is verified that the citrate ligand significantly affects the morphology of zinc oxalate particles, probably via its multiple roles of chelating, dispersing, and selective absorption. Thermodynamic equilibrium of the distribution of zinc species in an aqueous solution of Zn(Ⅱ)-citrate-oxalate-H_2O was estimated to explain the experimental results and to clarify the size and morphological evolution mechanism of the precipitated particles.

关键词： facile synthesis zinc oxalate flaky morphology citrate ligand one-pot synthesis

Reynolds number effect on compressible cylindrical cavity flow

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Chinese Journal of Aeronautics 2020年第2期33卷 456-464页

作者： Kung-Ming CHUNG Yi-xuan huang Kuan-huang LEE Keh-Chin CHANG Aerospace Science and Technology Research Center National Cheng Kung UniversityTainan 711China Department of Aeronautics and Astronautics National Cheng Kung UniversityTainan 701China

Presence of a cavity changes the mean and fluctuating pressure distributions inside and near the *** cylindrical cavity flow,the diameter-to-depth ratio is the dominant *** this study,flow is naturally developed along a flat plate with two different lengths,resulting in different incoming boundary layer thicknesses ahead of the *** effect of Reynolds number based on incoming boundary layer thickness on characteristics of mean and fluctuating pressure distributions is *** sensitive paint was also used to visualize the mean surface pressure *** effect of Reynolds number on the classification of compressible cylindrical cavity flow and self-sustained oscillating frequency is not *** increase in Reynolds number results in a reduction in the value of differential pressure or momentum flux near the rear edge.

关键词： Cavity flow Compressible flow Convection velocity Open cavity Oscillation

Facile synthesis of monodispersed copper oxalate flaky particles in the presence of EDTA

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International Journal of Minerals,Metallurgy and Materials 2018年第7期25卷 762-769页

作者： Xing Chert kai huang Cheng-yan Wang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Lab of Green Recycling and Extraction of Metals University of Science and Technology BeijingBeijing 100083China

Monodispersed copper oxalate paxticles with flaky morphology were prepared via a simple one-pot synthesis method. Scanning electron microscope （SEM）, X-ray diffraction （XRD）, and fourier tza^sform infraJced （FTIR） spectra were used to characterize paxticle mor- phology, size, phase composition, and functional groups. It was found that the presence of ethylenediaminetetzaacetic acid （EDTA） and the solution pH value had strong influence on the morphological and size evolution of the precipitated particles. On the basis of controlled re- lease of copper ions from a Cu2＋-EDTA complex and Weimazn＇s law, a stzategy for the controlled synthesis of monodispersed copper oxa- late paxticles was designed by refemng to the basic mode of the St0ber method. The inherent nature of crystallization to form the flaky solid in the early stage of precipitation as well as the driving force of the long-lasting low supersaturation in the growth stage was proposed to ex- plain the size and morphological evolution of the copper oxalate precipitates. Thermodynamic equilibrium concentrations of copper（II） spe- cies in the Cu（II）-EDTA-oxalate-H20 solution system were calculated to help explain the possible formation mechaNsm of copper oxalate precipitates.

关键词： copper oxalate flaky morphology ethylenediaminetetzaacetic acid one-pot synthesis

An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion

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Petroleum Science 2024年第1期21卷 352-365页

作者： kai-xuan Qiu Jia Li Dong Feng Shi-Ming Wei Gang Lei Jiangmen Laboratory of Carbon Science and Technology Jiangmen529100GuangdongChina The Hong Kong University of Science and Technology(Guangzhou) Guangzhou511400GuangdongChina China University of Geosciences(Beijing) Beijing100083China China University of Petroleum(Beijing) Beijing102249China China University of Geosciences(Wuhan) Wuhan430074HubeiChina Shenzhen Research Institute China University of GeosciencesShenzhen518063GuangdongChina

In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture *** has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture *** addition,most of the existing models are solved analytically based on Laplace transform and numerical ***,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix *** simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the ***,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by ***,a relationship between oil rate and production time in real-time space is *** new model is verified against classical analytical *** the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,***,the new model also has an excellent agreement with the numerical *** model is then applied to two actual tight oil wells completed in western Canada sedimentary *** identifying the flow regime,the solution suitably matches the field production data,and the model parameters are *** these output parameters,we can accurately forecast the production and even estimate the petrophysical properties.

关键词： Analytical solution Unconventional reservoir Variable matrix Simultaneous flow

Sunspot rotation and magnetic transients associated with flares in NOAAAR 11429

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Research in Astronomy and Astrophysics 2017年第8期17卷 47-56页

作者： Jian-Chuan Zheng Zhi-Liang Yang Jian-Peng Guo kai-Ming Guo Hui huang xuan Song Wei-Xing Wan Department of Astronomy Beijing Normal University Beijing 100875 China Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy ofSciences Beijing 100029 China College of Earth Sciences University of Chinese Academy of Sciences Beijing 100049 China

We analyze sunspot rotation and magnetic transients in NOAA AR 11429 during two X-class(X5.4 and X1.3)flares using data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory.A large leading sunspot with positive magnetic polarity rotated *** expected,the rotation was significantly affected by the two *** transients induced by the flares were clearly evident in the sunspots with negative *** were moving across the sunspots with speed of order 3-7 km ***,the trend of magnetic flux evolution in these sunspots exhibited changes associated with the *** results may shed light on understanding the evolution of sunspots.

关键词： sunspots—Sun rotation—Sun magnetic fields

Discrete element modeling of sand behavior in a biaxial shear test

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第9期9卷 1176-1183页

作者： Zhi-yi huang Zhong-xuan YANG Zhen-yu WANG Department of Civil Engineering Zhejiang University Hangzhou 310027 China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310027 China Department of Civil Engineering The University of Hong Kong Hong Kong China

The mechanical behavior of sand is very complex, and depends on factors including confining pressure, density, and drainage condition. A soil mass can be contractive or dilative when subjected to shear loading, and eventually reaches an ultimate state, referred to as the critical state in soil mechanics. Conventional approach to explore the mechanical behavior of sand mainly relies on the experimental tests in laboratory. This paper gives an alternative view to this subject using discrete element method (DEM), which has attracted much attention in recent years. The implementation of the DEM is carried out by a series of numerical tests on granular assemblies with varying initial densities and confining pressures, under different test configurations. The results demonstrate that such numerical simulations can produce correct responses of the sand behavior in general, including the critical state response, as compared to experimental observations. In addition, the DEM can further provide details of the microstructure evolutions during shearing processes, and the resulting induced anisotropy can be fully captured and quantified in the particle scale.

关键词： Granular soil behavior Critical state Microstructure Discrete element method (DEM)

Machine learning with active pharmaceutical ingredient/polymer interaction mechanism:Prediction for complex phase behaviors of pharmaceuticals and formulations

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Chinese Journal of Chemical Engineering 2024年第2期66卷 263-272页

作者： kai Ge Yiping huang Yuanhui Ji Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research School of Chemistry and Chemical EngineeringSoutheast UniversityNanjing 211189China

The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceutical *** this work,a developed machine-learning model efficiently predicts the solubility of APIs in polymers by learning the phase equilibrium principle and using a few molecular *** the few-shot learning framework,thermodynamic theory(perturbed-chain statistical associating fluid theory)was used for data augmentation,and computational chemistry was applied for molecular descriptors'*** results showed that the developed machine-learning model can predict the API-polymer phase diagram accurately,broaden the solubility data of APIs in polymers,and reproduce the relationship between API solubility and the interaction mechanisms between API and polymer successfully,which provided efficient guidance for the development of pharmaceutical formulations.

关键词： Multi-task machine learning Density functional theory Hydrogen bond interaction Miscibility Solubility

Microstructural evolution of Al-Si coating and its influence on high temperature tribological behavior of ultra-high strength steel against H13 steel

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Journal of Iron and Steel Research International 2017年第10期24卷 1048-1058页

作者： Meng-xuan Guo kai-xiang Gao Wu-rong Wang Xi-cheng Wei School of Materials Science and Engineering Shanghai UniversityShanghai 200072China

Al-Si coated ultra-high strength steel（UHSS）has been commonly applied in hot stamping *** influence of austenitizing temperature on microstructure of Al-Si coating of UHSS during hot stamping process and its tribological behavior against H13 steel under elevated temperature were simulatively *** austenitizing temperature of Al-Si coated UHSS and its microstructual evolution were confirmed and analyzed by differential scanning calorimetry and scanning electron microscopy.A novel approach to tribological testing by replicating hot stamping process temperature history was *** show that the hard and stable phases Fe_2Al_5＋FeAl_2 formed on Al-Si coating surface after exposure to 930°C for 5 min,which was found to be correlated to the tribological behavior of *** friction coefficient of coated steel was more stable and higher than that of uncoated *** main wear mechanism of Al-Si coated UHSS was adhesion wear,while abrasive wear was dominant for the uncoated UHSS.

关键词： Hot stamping Al-Si coating Ultra-high strength steel Intermetallic compound Diffusion Friction coefficient Adhesive wear

Past review,current progress,and challenges ahead on the cocktail party problem

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Frontiers of Information Technology & Electronic Engineering 2018年第1期19卷 40-63页

作者： Yan-min QIAN Chao WENG xuan-kai CHANG Shuai WANG Dong YU Tencent AI Lab Tencent Bellevue 98004 USA Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

The cocktail party problem,i.e.,tracing and recognizing the speech of a specific speaker when multiple speakers talk simultaneously,is one of the critical problems yet to be solved to enable the wide application of automatic speech recognition(ASR) *** this overview paper,we review the techniques proposed in the last two decades in attacking this *** focus our discussions on the speech separation problem given its central role in the cocktail party environment,and describe the conventional single-channel techniques such as computational auditory scene analysis(CASA),non-negative matrix factorization(NMF) and generative models,the conventional multi-channel techniques such as beamforming and multi-channel blind source separation,and the newly developed deep learning-based techniques,such as deep clustering(DPCL),the deep attractor network(DANet),and permutation invariant training(PIT).We also present techniques developed to improve ASR accuracy and speaker identification in the cocktail party *** argue effectively exploiting information in the microphone array,the acoustic training set,and the language itself using a more powerful *** optimization ob jective and techniques will be the approach to solving the cocktail party problem.

关键词： Cocktail party problem Computational auditory scene analysis Non-negative matrix factorization Permutation invariant training Multi-talker speech processing