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Large eddy simulation of transient transport and entrapment of particle during slab continuous casting

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Journal of Iron and Steel Research(International) 2022年第2期29卷 247-262页

作者： Yan-Bin Yin Jiong-ming Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China

To investigate the transient transport and entrapment of argon bubbles and inclusions simultaneously during continuous casting,a 3D large eddy simulation model coupling molten steel flow,solidification and particle motion was constructed.In this model,momentum transfer between molten steel and argon bubbles was performed by two-way coupling.The predicted results indicate that argon bubble injection changed the flow pattern of molten steel and the inclusion motion in the liquid pool.Consequently,the inclusion capture near the solidifying front was changed.In addition,measurements of bubbles and inclusions in the obtained samples were performed by methods of optical microscope examination and galvanostatic electrolysis.The results show a favorable agreement between the model predictions and the measured results,which validate the mathematical model.Furthermore,the predicted results of the inclusion entrapment in the case with argon bubble injection are more compatible with the measurements than those in the case without argon bubble injection.

关键词： Large eddy simulation Slab continuous casting Flow Solidification Argon bubble injection Particle motion Particle entrapment

A Dual-Task Learning Approach for Bearing Anomaly Detection and State Evaluation of Safe Region

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 229-241页

作者： Yuhua yin Zhiliang Liu bin Guo Mingjian Zuo School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Qingdao International Academician Park Research Institute Qingdao 266041China

Predictive maintenance has emerged as an effective tool for curbing maintenance costs,yet prevailing research predominantly concentrates on the abnormal phases.Within the ostensibly stable healthy phase,the reliance on anomaly detection to preempt equipment malfunctions faces the challenge of sudden anomaly discernment.To address this challenge,this paper proposes a dual-task learning approach for bearing anomaly detection and state evaluation of safe regions.The proposed method transforms the execution of the two tasks into an optimization issue of the hypersphere center.By leveraging the monotonicity and distinguishability pertinent to the tasks as the foundation for optimization,it reconstructs the SVDD model to ensure equilibrium in the model’s performance across the two tasks.Subsequent experiments verify the proposed method’s effectiveness,which is interpreted from the perspectives of parameter adjustment and enveloping trade-offs.In the meantime,experimental results also show two deficiencies in anomaly detection accuracy and state evaluation metrics.Their theoretical analysis inspires us to focus on feature extraction and data collection to achieve improvements.The proposed method lays the foundation for realizing predictive maintenance in a healthy stage by improving condition awareness in safe regions.

关键词： Bearing condition monitoring Anomaly detection Safe region Support vector data description

Spatiotemporal Pattern of Cultivated Land Pressure and Its Influencing Factors in the Huaihai Economic Zone, China

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Chinese Geographical Science 2023年第2期33卷 287-303页

作者： LI Yi FANG bin LI Yurui FENG Weilun yin Xu School of Geography Nanjing Normal UniversityNanjing 210023China Research Center of New Urbanization and Land Problem Nanjing Normal UniversityNanjing 210023China Jiangsu Provincial Geographic Information Resources Development and Utilization Cooperative Innovation Center Nanjing 210023China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of SciencesBeijing 100101China School of Geographic Science Hebei Normal UniversityShijiazhuang 050024China

Cultivated land pressure represents a direct reflection of grain security. Existing relevant studies rarely approached the spatiotemporal pattern of cultivated land pressure or the spatial heterogeneity of its influencing factors from the level of economic zones.Taking the Huaihai Economic Zone(HEZ), China for case analysis, this study investigated the spatiotemporal pattern of cultivated land pressure in diverse periods from 2000 to 2018 based on a modified cultivated land pressure index and spatial correlation models. On this basis, it explored the influencing factors of the spatial differentiation of cultivated land pressure in the late stage of the study using geographical detector as well as multi-scale geographically weighted regression model. The results indicated that: 1) in the study period, the global cultivated land pressure index of the study area decreased gradually, but cultivated land pressure increased locally in a significant way, especially in the central and southern Shandong Province;2) the spatial pattern of cultivated land pressure manifested global clustering features. Hot and secondary-hot spots presented a narrowing and clustering trend, whereas cold and secondary-cold spots manifested a spreading and clustering trend;3) average slope, the proportion of non-grain crops, population urbanization rate, and multiple cropping index have significant effects on the spatial differentiation of cultivated land pressure. The former three factors were positively correlated with cultivated land pressure, and the last factor was negatively correlated with cultivated land pressure;and 4) the amount of cultivated land has increased in the central and southern Shandong Province through land consolidation which, nonetheless, failed to improve the grain production. In regards to major grain producing areas similar to the HEZ in China, the authors suggest that great importance should be given to the balance of the quality and quantity of cultivated land, the optimization of agricultural production factors an

关键词： cultivated land pressure spatiotemporal pattern influencing factors Huaihai Economic Zone China

Monitoring the change in horizontal stress with multi-wave time-lapse seismic response based on nonlinear elasticity theory

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Petroleum Science 2023年第2期20卷 815-826页

作者： Fu-bin Chen Zhao-Yun Zong Xing-Yao yin School of Geosciences China University of Petroleum East ChinaQingdaoShandong266580China Laoshan Laboratory QingdaoShandong266580China Shandong Provincial Key Laboratory of Deep Oil and Gas QingdaoShandong266580China

Monitoring the change in horizontal stress from the geophysical data is a tough challenge, and it has a crucial impact on broad practical scenarios which involve reservoir exploration and development, carbon dioxide (CO_(2)) injection and storage, shallow surface prospecting and deep-earth structure description. The change in in-situ stress induced by hydrocarbon production and localized tectonic movements causes the changes in rock mechanic properties (e.g. wave velocities, density and anisotropy) and further causes the changes in seismic amplitudes, phases and travel times. In this study, the nonlinear elasticity theory that regards the rock skeleton (solid phase) and pore fluid as an effective whole is used to characterize the effect of horizontal principal stress on rock overall elastic properties and the stress-dependent anisotropy parameters are therefore formulated. Then the approximate P-wave, SV-wave and SH-wave angle-dependent reflection coefficient equations for the horizontal-stress-induced anisotropic media are proposed. It is shown that, on the different reflectors, the stress-induced relative changes in reflectivities (i.e., relative difference) of elastic parameters (i.e., P- and S-wave velocities and density) are much less than the changes in contrasts of anisotropy parameters. Therefore, the effects of stress change on the reflectivities of three elastic parameters are reasonably neglected to further propose an AVO inversion approach incorporating P-, SH- and SV-wave information to estimate the change in horizontal principal stress from the corresponding time-lapse seismic data. Compared with the existing methods, our method eliminates the need for man-made rock-physical or fitting parameters, providing more stable predictive power. 1D test illustrates that the estimated result from time-lapse P-wave reflection data shows the most reasonable agreement with the real model, while the estimated result from SH-wave reflection data shows the largest bias. 2D test illustrates the feasibility of the pr

关键词： Monitoring change in horizontal stress Multi-wave reflection coefficients Nonlinear elasticity theory Time-lapse seismic data

Comprehensive utilization of solid waste resources: Development of wet shotcrete for mines

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International Journal of Minerals,Metallurgy and Materials 2023年第9期30卷 1692-1704页

作者： Yafei Hu Shenghua yin Keqing Li Bo Zhang bin Han School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Ministry of Education of China for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China

The development of solid waste resources as constituent materials for wet shotcrete has significant economic and environmental advantages. In this study, the concept of using tailings as aggregate and fly ash and slag powder as auxiliary cementitious material is proposed and experiments are carried out by response surface methodology(RSM). Multivariate nonlinear response models are constructed to investigate the effect of factors on the uniaxial compressive strength(UCS) of tailings wet shotcrete(TWSC). The UCS of TWSC is predicted and optimized by constructing Gaussian process regression(GPR) and genetic algorithm(GA). The UCS of TWSC is gradually enhanced with the increase of slag powder dosage and fineness modulus, and it is enhanced first and then decreased with the increase of fly ash dosage. The microstructure of TWSC has the highest gray value and the highest UCS when the fly ash dosage is about 120 kg·m^(-3). The GPR–GA model constructed in this study achieves high accuracy prediction and optimization of the UCS of TWSC under multi-factor conditions.

关键词： tailings solid waste wet shotcrete machine learning mix proportion

Numerical simulation and printability analysis of fused deposition modeling with dual-temperature control

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Bio-Design and Manufacturing 2023年第2期6卷 174-188页

作者： Xiaodan Huo bin Zhang Qianglong Han Yong Huang Jun yin The State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310028China Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310028China Department of Mechanical and Aerospace Engineering University of FloridaGainesvilleFL 32611USA

Ideal tissue engineering scaffolds need interconnected pores and high porosity to enable cell survival,migration,proliferation,and differentiation.However,obtaining a high-resolution structure is difficult with traditional one-temperature control fused deposition modeling(FDM).In this study,we propose a dual-temperature control method to improve printability.A numerical model is developed in which the viscosity is a function of temperature and shear rate to study the influence of two different temperature control modes.Quantitative tests are used to assess filament formation and shape fidelity,including one-dimensional filament printing,deposition at corners,fusion,and collapse.By using dual-temperature control,the width of the deposited poly(ε-caprolactone)filament is reduced to 50μm.The comparative results of both the experimental method and numerical simulation suggest that the dual-temperature control FDM can manufacture spatially arranged constructs and presents a promising application in tissue engineering。

关键词： Fused deposition modeling(FDM) Dual-temperature control Filament deposition Printing resolution Viscosity

Abnormal Systemic and Ocular Responses to the Valsalva Manoeuvre in Primary Open-Angle Glaucoma:A Case for Autonomic Failure?

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Current Medical Science 2023年第2期43卷 376-383页

作者： bin-bin LIU Bo-wen ZHAO Fei-peng WU Tian HU yin ZHAO Hong ZHANG Department of Ophthalmology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

Objective This study aimed to examine the association of primary open-angle glaucoma(POAG)with autonomic dysfunction by assessing the differences in systemic and ocular responses to an autonomic provocation test,the Valsalva manoeuvre(VM),between POAG patients and normal subjects.Methods Forty POAG and forty control subjects were subjected to the VM.Systemic and ocular parameters were measured at baseline,phase 2,and phase 4 of the VM(VM2 and VM4),where VM2 and VM4 are sympathetic and parasympathetic nervous activation states,respectively.Heart rate variability was used to assess the autonomic nervous activity,among which the high-frequency component(HF)and the low-frequency(LF)/HF ratio were used as indices of parasympathetic and sympathetic activation,respectively.Results POAG patients demonstrated higher sympathetic activation(LF/HF ratio median:2.17 vs.1.53,P=0.000)than controls at baseline and exhibited attenuated sympathetic and parasympathetic responses(a smaller change in LF/HF and HF values)during the VM than controls.During VM,the intraocular pressure(IOP),mean blood pressure(MAP),mean ocular perfusion pressure(MOPP),and the Schlemm’s canal area(SCAR)increased from baseline to VM2 and then decreased from VM2 to VM4 in both the POAG and control groups(all P<0.05).However,when we compared the changes above,the fluctuations in IOP,MAP,and MOPP were more pronounced in POAG than in controls(all P<0.05),while the changes in amplitudes of SCAR were smaller in POAG(P<0.05).Furthermore,from VM2 to VM4,the choroid thickness(ChT)in the POAG group was significantly decreased,while it was unchanged in normal subjects(P=0.258).A regression analysis showed a significant correlation of the baseline LF/HF with IOP change values(ΔIOP)from baseline to VM2 in POAG(R^(2)=0.147,P=0.014).Conclusion Patients with POAG showed more pronounced fluctuations in IOP,MAP,MOPP and ChT during the VM than controls.These reactions could be associated with autonomic dysfunction in POAG.

关键词： primary open-angle glaucoma Valsalva manoeuvre autonomic dysfunction intraocular pressure Schlemm’s canal

Photo-triggered Intramolecular Radical Tandem Regioselective Alkylation/Cyclization of 1,6-Dienes with Redox-Active Esters Enabled by an EDA Complex

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Chinese Journal of Chemistry 2023年第1期41卷 37-42页

作者： bin Sun Lan Ling Xiaohui Zhuang Lulu Yang Jieli yin Can Jin Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals Zhejiang University of TechnologyHangzhouZhejiang 310014China College of Pharmaceutical Sciences Zhejiang University of TechnologyHangzhouZhejiang 310014China

A photocatalyst-and metal-free radical tandem alkylation/cyclization between 1,6-dienes and redox-active esters has been devel-oped,affording a series of N-aryl pyrrolidine-2-ones in moderate to good yields.The transformation is driven by the formation of an electron-donor-acceptor(EDA)complex and a subsequent single electron transfer(SET)process.This photocatalyst-free protocol features excellent regioselectivity,mild conditions and broad substrate scope,providing a facile access to 3-alkyl-3,4-dimethyl-1-phe-nylpyrrolidin-2-one.

关键词： Alkylation Cyclization EDA Complex Pyrrolidone Photocatalysis

Is it inflammatory linear verrucous epidermal nevus or linear psoriasis？

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Chinese Medical Journal 2013年第9期126卷 1794-1795页

作者： yin bin Department of Dermatovenereology West China Hospital Sichuan UmversityChengdu Sichuan 610041 China

To the editor： Inflammatory linear verrucous epidermal nevus （ILVEN） is an epidermal nevus reflecting genetic mosaicism.1It resembles linear psoriasis clinically and histologically, and there are no generally accepted pathognomonic features.2 Therefore differentiation of the two diseases has always been difficult in clinical settings.

关键词：镶嵌现象一氧化氮胰岛素银屑病痣