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Quantitative Prediction of Reduction in Large Pipe Setting Round Process

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Chinese Journal of Mechanical Engineering 2013年第4期26卷 722-729页

作者： ZHAO jun ZHAN Peipei MA Rui zhai Ruixue College of Mechanical Engineering Yanshan University

The control manner during the process to ensure the quality of pipe products mainly relies on the operator’s experience, so it is very necessary to study the setting round process and obtain its spring-back law. The setting round process is shaping an oval section pipe into circular section, so it is difficult to provide a quantificational analysis for its spring-back process because of the curvature inequality of pipe section neutral layer. However, the spring-back law of the circle-oval process can be easily predicted. The experimental method is firstly used to establish the equivalent effect between the setting round process and the circle-oval process. The setting round process can be converted into the circle-oval process. There are two difficulties in the theoretical analysis for the circle-oval process: elastic-plastic bending problem of curved beam; statically indeterminate problem. A quantitative analytic method for the circle-oval process is presented on the basis of combination of the spring-back law of plane curved beam with the element dividing idea in finite element method. The ovality after unloading versus the relative reduction is plotted with analytical and experimental results respectively, which shows a fair agreement. Finally, the method of quantitative prediction of reduction for large pipe setting round is given based on the equivalent effect and the analytical results. Five pipes, which are needed to be set round, are used to carry out experiment so as to verify this method. The results of verification experiment indicates that, in the experimental range, the residual ovality are all under 0.35% after the once only setting round with the theoretical prediction reductions. It is much less than the 1% requirement of pipe standard. Applying the established theoretical analysis is able to correct the pipe ovality with sufficient accuracy, which provides theoretical direction to plant use.

关键词： large pipes setting round circle-oval process spring-back analysis

An Iterative Compensation Algorithm for Springback Control in Plane Deformation and Its Application

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 212-223页

作者： Rui Ma Chunge Wang Ruixue zhai jun Zhao Key Laboratory of Advanced Forging & Stamping Technology and ScienceMinistry of Education of China Yanshan University College of Mechanical Engineering Yanshan University College of Mechanical and Energy Engineering Ningbo Institute of Technology Zhejiang University Key Laboratory of Roll Forming Technology Research

In order to solve the springback problem in sheet metal forming, the trial and error method is a widely used method in the factory, which is time-consuming and costly for its non-direction and non-quantitative. Finite element simulation is an e ective method to predict the springback of complex shape parts, but its precision is sensitive to the simulation model, particularly material model and boundary conditions. In this paper, the simple iterative method is introduced to establish the iterative compensation algorithm, and the convergence criterion of iterative parameters is put forward. In addition, the new algorithm is applied to the V-free bending and stretch-bending processes, and the convergence of curvature and bending angle is proved theoretically and verified experimentally. At the same time,the iterative compensation experiments for plane bending show that, the new method can predict the next compensaantido tnh ev atlaureg ebta cseurdv oatnu trhe ew sitphri tnhgeb earcrko ro fo fe laecshs ttehsat,n s0 o. 5 th%a ta rteh eo btatraigneet db aefntedri n2 g-3 a nitgelrea tiwoitnhs.t Thhei se rrreosre aorf clhe sps rtohpaons e±s 0 a.1%new iterative compensation algorithm to predict springback in sheet metal forming process, where each compensation value depends only on the iteration parameter di erence before and after springback for the same forming process of same material.

关键词： Springback control Iterative compensation algorithm Convergence criterion V-free bending Stretchbending

Development and application of a water pollution emergency response system for the Three Gorges Reservoir in the Yangtze River, China

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Journal of Environmental Sciences 2011年第4期23卷 595-600页

作者： Qiang He Shujuan Peng jun zhai Haiwen Xiao Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Ministry of Education Chongqing University Chongqing 400045 China.

There are many watercraft and production accidents in the Three Gorges Reservoir Area （TGRA） of the Yangtze River in China every year. Accidents threaten the water quality of the 1085 km 2 surface area of the TGRA and millions of local people if oil and chemical leakage were to occur. A water pollution management system for emergency response （WPMS ER） was therefore designed for the management of pollution in this area. An integrated geographic information system （GIS）-based water pollution management information system for the TGRA, called WPMS ER TGRA, was developed in this study. ArcGIS engine was used as the system development platform, and Visual Basic as the programming language. The models for hydraulic and water quality simulation and the generation of body-fitted coordinates were developed and programmed as a dynamically linked library file using Visual Basic, and they can be launched by other computer programs. Subsequently, the GIS-based information system was applied to the emergency water pollution management of a shipwreck releasing 10 tons of phenol into the Yangtze River during two hours. The results showed that WPMS ER TGRA can assist with emergency water pollution management and simulate the transfer and diffusion of accidental pollutants in the river. Furthermore, it can quickly identify the affected area and how it will change over time within a few minutes of an accident occurring.

关键词： water pollution emergency emergency response management information system the Three Gorges Reservoir

An Effective Platform for SARS-CoV-2 Prevention by Combining Neutralization and RNAi Technology

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Chinese Journal of Polymer Science 2023年第3期41卷 327-333,I0005页

作者： jun-xiang Zhou Xue Yin Hao-jun Liang Department of Polymer Science and Engineering Hefei National Research Center for Physical Sciences at the Microscale iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) University of Science and Technology of China

At present,the coronavirus disease 2019(COVID-19)pandemic is a global health *** all over the globe are urgently looking forward to an effective solution to prevent the spread of the epidemic and avoid more casualties at an early *** this study,we establish an effective platform for the prevention of SARS-CoV-2 by combining the neutralization strategy and RNAi *** protect normal cells from infection,the customized cells are constructed to stably express viral antigenic receptor ACE2 on the cell *** modified cells are used as bait for inducing the viral *** transcription and replication activities of viral genome are intercepted subsequently by the intracellular sh RNAs,which are complementary to the viral gene fragments.A pseudotyped virus reconstructed from the HIV lentivirus is utilized as a virus model,by which we validate the feasibility and effectiveness of our strategy in *** work establishes an initial model and lays the foundation for future prevention and treatment of various RNA viruses.

关键词： SARS-CoV-2 Neutralization ACE2 RNAi Pseudotypedvirus

Recovery of PET-quenched Fluorescent Conjugated Polymers with Aza-15-crown-5 as Pendant Groups on Interaction with Ions

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Chinese Journal of Polymer Science 2014年第3期32卷 371-376页

作者：曹靖 jun-xiang Feng 吴诗 College of Chemistry Xiangtan University School of Pharmacy Hubei University of Science and Technology

Novel conjugated polymers with aza-15-crown-5 as pendant groups, P1 were synthesized by the Sonogashira coupling reaction. The polymer P1 was found to show fluorescence en-hancement response towards Ba2＋. The gradual recovery and turning-point of emission intensity of polymers appeared in the addition of Ba2＋, which provided good evidence for the fluorescence amplification mechanism of conjugated polymers.

关键词： Conjugated polymer Fluorescence recovery,

GSM-MRF based classification approach for real-time moving object detection

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 250-255页

作者： xiang PAN Yi-jun WU Institute of Information and Communication Engineering Zhejiang University Hangzhou 310027 China

Statistical and contextual information are typically used to detect moving regions in image sequences for a fixed *** this paper,we propose a fast and stable linear discriminant approach based on Gaussian Single Model(GSM)and Markov Random Field(MRF).The performance of GSM is analyzed first,and then two main improvements corresponding to the drawbacks of GSM are proposed:the latest filtered data based update scheme of the background model and the linear classification judgment rule based on spatial-temporal feature specified by *** results show that the proposed method runs more rapidly and accurately when compared with other methods.

关键词： Moving object detection Markov Random Field (MRF) Gaussian Single Model (GSM) Fisher Linear Discriminant Analysis (FLDA)

A Novel Design of a Pre-separation Panel Structure to Protect Against the Impact of an Explosion in an Aircraft Plenum Chamber

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Acta Mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zongxing Liu xiang Yang jun Liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COMAC Shanghai Aircraft Design and Research Institute Shanghai 201210China

To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast ***,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage ***,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation ***,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact *** calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the *** residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged *** results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.

关键词： Pre-separation panel structure Explosive response Residual strength Aircraft plenum chamber Least risk bomb location

Effect of Particle Size on Target Sintering Behavior of Cubic ITO Nanopowders

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Journal of Wuhan University of Technology(Materials Science) 2020年第6期35卷 1098-1103页

作者： zhai Xiaoyu PENG xiang MA Yunqian LIU Ting LIU Jiaxiang Beijing Key Laboratory of Electrochemical Process and Technology for Materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically *** experimental results show that the relative density of ITO green bodies decreases with the increase of ITO particle *** the particle size is 10.7 nm,the relative density of ITO green bodies rises to the maximum value of 56.6%.The resistivity declines exponentially with the increase of particle size,which satisfies the exponential equation of R=exp(-41.823 × d).When the particle size is 41.6 nm,the resistivity reaches the minimum value of 0.8 Ω·*** relative density of ITO target decreases with the increase of particle *** particles can increase the driving force of densification in initial *** mobility,caused by grain boundary scattering,will increase due to the increase of particle size or the decrease of grain boundary *** the particle size is 10.7 nm,the target with compact grain stacking and low porosity shows a maximum relative density of 99.25%,and the resistivity reaches the minimum value of 0.34×10^-3 Ω·cm.

关键词： indium tin oxide nanoparticles particle size indium tin oxide target relative density resistivity

Tumor-suppressor effects of chemical functional groups in an in vitro co-culture system

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Frontiers of Materials Science 2014年第2期8卷 136-141页

作者： Su-Ju xu Fu-zhai CUI xiang-Dong KONG Institute of Biomaterials and Marine Biological Resources College of Life Sciences Zhejiang Sci-Tech University Hangzhou 310018 China Institute of Regenerative Medicine and Biomimetic Materials School of Materials Science and Engineering Tsinghua University Beijing 100084 China

Liver normal cells and cancer cells co-cultured on surfaces modified by different chemical functional groups, including mercapto （-SH）, hydroxyl （-OH） and methyl （-CHz） groups. The results showed that different cells exhibited changes in response to different surfaces. Normal cells on -SH surface exhibited the smallest contact area with mostly rounded morphology, which led to the death of cancer cells, while cancer cells could not grow on -CH3 groups, which also died. In the co-culture system, the -CH3 group exhibited its unique effect that could trigger the death of cancer cells and had no effects on normal cells. Our findings provide useful information on strategies for the design of efficient and safe regenerative medicine materials.

关键词： tumor suppressor chemical functional group co-culture system regen-erative medicine material