Zhu J.,Zhejiang University of Technology |
Zhu J.,Huzhou Vocational and Technical College |
Mao J.,Zhejiang University of Technology |
Bao S.,Zhejiang University of Technology |
And 2 more authors.
Journal of Pressure Vessel Technology, Transactions of the ASME | Year: 2017
The so-called "in-vessel retention (IVR)" is a basic strategy for severe accident (SA) mitigation of some advanced nuclear power plants (NPPs). The IVR strategy is to keep the reactor pressure vessel (RPV) intact under SA like core meltdown condition. During the IVR, the core melt (â 1/41327 °C) is collected in the lower head (LH) of the RPV, while the external surface of RPV is submerged in the water. Through external cooling of the RPV, the structural integrity is assumed to be maintained within a prescribed period of time. The maximum thermal loading is referred to critical heat flux (CHF) on the inside, while the external surface is considered to perform in the environment of the boiling crisis point (â 1/4130 °C). Due to the high temperature gradients, the failure mechanisms of the RPV is found to span a wide range of structural behaviors across the wall thickness, such as melt-through, creep damage, plastic yielding as well as thermal expansion. Besides CHF, the pressurized core meltdown was another evident threat to the RPV integrity, as indicated in the Fukushima accident on 2011. In illustrating the effects of internal pressures and individual CHF on the failure behaviors, three typical RPVs with geometric discontinuity caused by local material melting were adopted for the comparative study. Through finite-element method (FEM), the RPV structural behaviors were investigated in terms of deformation, stress, plastic strain, creep, and damage. Finally, some important conclusions are summarized in the concluding remark. Such comparative study provides insight and better understanding for the RPV safety margin under the IVR condition. Copyright © 2017 by ASME.
Zhong X.,China Institute of Technology |
Zhou B.,Huzhou Vocational and Technical College
International Review on Computers and Software | Year: 2011
An inter-cluster cooperative node selection scheme with low energy-cost is proposed for the energy -constrained wireless sensor networks. Pre-set an energy threshold first and determine a cooperative node set. Then estimate information of channels between inner-cluster cooperative nodes and cluster head nodes with a blind channel estimation algorithm that requires small amount data. The optimum inner-cluster nodes are selected as the cooperative nodes of the cluster head nodes by considering comprehensively channel states and residual energy. The blind channel estimation is then turn into the unconstrained optimization which is then resolved by quadratic programming iterative weighted method. Theoretical analysis, mathematical models, and simulation results show that the new algorithm can obtain channels information by mean of a few data. © 2011 Praise Worthy Prize S.r.l. - All rights reserved.
Zhou B.,Huzhou Vocational and Technical College |
Kui X.,Huzhou Vocational and Technical College |
Qu Y.,Zhejiang University of Media and Communications
Proceedings - 10th IEEE International Conference on Computer and Information Technology, CIT-2010, 7th IEEE International Conference on Embedded Software and Systems, ICESS-2010, ScalCom-2010 | Year: 2010
The conventional teaching model is broken in Mode CDIO, in which, with the carrier of project, the educational idea based on project-learning and the principle of teaching integration are embodied, and students play main roles well, while faculty play leading rolls. Taking Principle and Application of Single-chip Computer as an example, we expatiate on the implementation of the teaching reform in Mode CDIO and get an improved teaching quality. © 2010 IEEE.
Huang K.,Huzhou Vocational and Technical College |
Zou L.,Fuzhou University
Journal of Natural Disasters | Year: 2014
In order to reduce the earthquake response and prevent collapse with oversize bottom displacement of soft-first story structure, this paper proposed a seismic control system for a soft-first story structure. The structure adopted a semi-active control method with magnetorheological dampers in the soft-first story. Considering the adverse influences of vertical earthquake, this paper established the dynamic model and vibration-control equations of structure under bi-directional coupling earthquake action. The LQR control algorithm was used for the earthquake response analysis of the structure. The analysis results indicated that, the displacement response of the structure concentrates mainly on the flexible bottom layer in the uncontrolled case. For the semi-active control case, the displacements of bottom and top layer, acceleration and overturning moment at each layer are reduced significantly. In particular, the displacement of the bottom layer was reduced by 60% and more. Compared with horizontal earthquake, the seismic responses increased in the case of coupling earthquake. The increase of overturning moment is the most obvious. Therefore, the influence of vertical seismic motion should be considered in high seismic intensity region. The layer stiffness ratio can affect the control effect of the structure more greatly and it should be determined considering the displacement of the bottom, the top acceleration and the overturning moment. The SSI effect can reduce the control effect of structure.
Wang F.,Nanjing University of Science and Technology |
Hou F.D.,China Machinery International Engineering Design and Research Institute Co. East China Branch |
Liu X.Q.,Huzhou Vocational and Technical College
Applied Mechanics and Materials | Year: 2014
Double skin facade has been popular in China since new century. It provides challenges to deal with overheating problems in air cavity and improve energy saving effects in hot summer and cold winter climate zone in China. This paper develops a new ecological facade which includes three key elements: a ventilated double skin facade, a tillandsia usneoides plant curtain and watering. The biological characteristics especially the absorbtivity of tillandsia usneoides were analyzed via SEM scanning photographs. Bud scales and mesophyll cells of tillandsia usneoides are the main tissues to keep water. Then a method to construct an ecological double skin facade using condensation water was introduced. © (2014) Trans Tech Publications, Switzerland.
Long Z.X.,Institute of Urban Construction of Hangzhou Polytechnic |
Fan X.,Huzhou Vocational and Technical College
Applied Mechanics and Materials | Year: 2013
In order to analyze reliability for strength of pre-stressed pipe pile welded joints in common construction activities, perform checking calculation to welded joint strength in various construction activities with the weld check formula in consideration of the influence coefficient of the eccentrically loaded end plate, compare with the shear strength of the pipe pile end plate porthole and the tensile strength of the steel bar pier head, and analyze from overall safety of pipe pile application before obtain the conclusion: the strength of the weld joint made according to relative codes is far more than the strength of the weak part of the pipe pile, but some severe weld defects will make weld joint become the first part to be damaged. One recommendation is increase the joint strength between the anchorage hole of the pipe pile end plate and the pre-stressed steel bar pier head; the other is to make the new welding construction specifications for pipe pile joint, improve requirements to joint welding construction, reduce welding duration, reduce working strength and improve welding quality stability. © (2013) Trans Tech Publications, Switzerland.
Zhang S.,Huzhou Vocational and Technical College |
Zhang Y.,Huzhou Vocational and Technical College
Lecture Notes in Electrical Engineering | Year: 2015
To characterize the unblockability degree of one network, the authors explored the concept of network accessibility and proposed one approach for calculating the network accessibility index. The proposed approach considers network characteristics to help overcome the shortcomings of previous approaches to the calculation of accessibility measures. The proposed accessibility index can reflect the accessibility level of networks and has many potential uses. The index can serve as a guide in the design of transit networks and in the allocation of network flow. © Springer International Publishing Switzerland 2015.
Zhili X.,Huzhou Vocational and Technical College
Advance Journal of Food Science and Technology | Year: 2015
The study attempts to apply the virtual reality technology in food processing teaching, to analyze the algorithm in food processing, to improve the teaching quality and efficiency in order to save manpower and material resources. The development of virtual reality technology opens a new road to the progress of the food industry continuously, the development of virtual technology provides the technical support for efficient food processing methods, In the food processing teaching process, it can be effective to improve the teaching quality and efficiency combining virtual technology with food processing teaching, using the way of virtual animation and simulation. © Maxwell Scientific Organization, 2015.
Yu Z.,Huzhou Vocational and Technical College |
Zhou B.,Huzhou Vocational and Technical College
Applied Mechanics and Materials | Year: 2012
The conductive plastic is widely used in making sensitive materials such as angular displacement sensors with high-precision. The resistive film of the sensor is formed by spraying and its quality has a close relationship with the resistance liquid' density, spraying pressure and time, and drying temperature and time. We draw a conclusion from experiments that for the conductive plastic with carbon fillers, the optimal linearity is obtained under a pressure of 0.5-0.6Mpa in 6-8 seconds and the best abrasion resistance is obtained at a drying temperature of 175°C in 4 minutes when the liquid resistance contains 15% carbon. While for the conductive plastics with metal fillers, the optimal linearity is obtained under a pressure of 0.7-0.8Mpa in 5-6 seconds, and the best abrasion resistance is obtained at a drying temperature of 165°C in 4 minutes when the liquid resistance contains 6% metal fillers. The research results have some guiding significance in improving performance and lowering cost.
Huang F.,Zhejiang University |
Wang X.,Environmental Information Center |
Lou L.,Source Point |
Zhou Z.,Huzhou Vocational and Technical College |
Wu J.,Zhejiang University
Water Research | Year: 2010
Understanding the spatial distribution and apportioning the sources of water pollution are important in the study and efficient management of water resources. In this work, we considered data for 13 water quality variables collected during the year 2004 at 46 monitoring sites along the Qiantang River (China). Fuzzy comprehensive analysis categorized the data into three major pollution zones (low, moderate, and high) based on national quality standards for surface waters, China. Most sites classified as "low pollution zones" (LP) occurred in the main river channel, whereas those classified as "moderate and high pollution zones" (MP and HP, respectively) occurred in the tributaries. Factor analysis identified two potential pollution sources that explained 67% of the total variance in LP, two potential pollution sources that explained 73% of the total variance in MP, and three potential pollution sources that explained 80% of the total variance in HP. UNMIX was used to estimate contributions from identified pollution sources to each water quality variable and each monitoring site. Most water quality variables were influenced primarily by pollution due to industrial wastewater, agricultural activities and urban runoff. In LP, non-point source pollution such as agricultural runoff and urban runoff dominated; in MP and HP, mixed source pollution dominated. The pollution in the small tributaries was more serious than that in the main channel. These results provide information for developing better pollution control strategies for the Qiantang River. © 2009 Elsevier Ltd. All rights reserved.