A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in deta...A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in details. The operational principles of different sensors, technical flow of manufacturing, development of software systems of special functions, and the assessments of technical specification were also be introduced. This sensor adopted many new technologies, such as the applications of piezoresistant effect and heat sensitive effect can effectively measure the pressure and temperature, digital signal processing technology was used to extract and treat signals, and resist interference, encapsulation technology was used to keep the normal run of sensor under a harsh environment. Thus, the on-line compound multi-functional temperature/pressure sensor can be applied better to supervise the production of wood-based panels. All technical specifications of the compound multi-functional sensor were tested and the results met the requirements of the equipments.展开更多
Vacuum insulation panels provide unprecedented possibilities for renovating the existing building stock in a manner that reduces the thermal losses through the building envelope. This study is focused on the implement...Vacuum insulation panels provide unprecedented possibilities for renovating the existing building stock in a manner that reduces the thermal losses through the building envelope. This study is focused on the implementation of VIPs （vacuum insulation panels） in energy retrofit projects with rendered outer walls. Particular emphasis is put on reducing the thermal bridges due to mechanical fasteners and at the joints of the panels. These are evaluated through a parametric study of the impact of the thermal conductivity of the joints of the panels and the adjacent insulation layer as well as the material of the fasteners. The study is carried out with 3D FEM （finite element method） simulations software. Furthermore, the moisture conditions in the construction are studied. The dynamic moisture behavior of a wall construction is modeled with a two dimensional FEM model. The long term effects of vapor diffusion are investigated in terms of accumulated moisture and the risk of condensation. The results illustrate that vacuum insulation on the outside of the wall construction does not pose a moisture problem to the construction. The simulations are based on a draft of a new technical solution for the refurbishment of a building that is typical for the great Swedish building program of the 1970s.展开更多
This paper proposes the concept of projection curves based on the theory of CT image reconstruction to probe the internal structure of the working panel prior to formal mining of the working panel.As well as reducing ...This paper proposes the concept of projection curves based on the theory of CT image reconstruction to probe the internal structure of the working panel prior to formal mining of the working panel.As well as reducing costs,this method provides safe and efficient excavation of the working panel.According to the results of the numerical model and the actual working panel,the new method has been proven to be accurate in detecting the location of the fault that extends into the face.Concealed faults of the internal working panel,as well as the start and end points of the fault,can be detected by this method.Engineering practice has proven that the method is highly reliable,has a highly decisive impact on faults for coal mining,and can be used to guide the safe mining of the working panel.展开更多
Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakth...Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry.In this study,a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of ply-wood.The preparation technique of plywood was optimized,and the chemical structure,curing performance,crystallization property and thermal performance of the adhesive were investigated.Results showed that:(1)hot-pressing temperature played a decisive role in the performances of tannin-sucrose composite adhesives and it also had a very significant influence on the water resistance of plywood.(2)The preparation of tannin-sucrose composite adhesive was a process in which sucrose was transformed into furan aldehydes and then made cross-linking reaction with tannin.These composite adhesives could only get good bonding performances when the curing temperature was above 210℃.(3)The optimal plywood preparation technique was:hot-pressing tem-perature of 220℃,hot-pressing time of 1.2 min/mm,m(tannin):m(sucrose)of 60:40,and adhesive loading of 160 g/m^(2).The wet bonding strength in boiling water of the prepared plywood was 0.83 MPa,meeting the strength requirements of Type-I plywood in the standard of GB/T 17657-2013.(4)The curing temperature of tannin-sucrose composite adhesive was further decreased by lowering the temperature during the transformation of sucrose into 5-HMF,which was a key in subsequent research.展开更多
The production of wood-based panel was presented firstly in this paper. Some features of China’s wood-based panel industry were reviewed, including production bases, raw materials and main markets of wood-based panel...The production of wood-based panel was presented firstly in this paper. Some features of China’s wood-based panel industry were reviewed, including production bases, raw materials and main markets of wood-based panel. In addition, the trade flow of wood-based panel was described in the end.展开更多
基金This project was supported by China Postdoctoral Science Funds, Jiangsu Planned Projects for Postdoctoral Research Funds and Northeast Forestry University Research Funds.
文摘A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in details. The operational principles of different sensors, technical flow of manufacturing, development of software systems of special functions, and the assessments of technical specification were also be introduced. This sensor adopted many new technologies, such as the applications of piezoresistant effect and heat sensitive effect can effectively measure the pressure and temperature, digital signal processing technology was used to extract and treat signals, and resist interference, encapsulation technology was used to keep the normal run of sensor under a harsh environment. Thus, the on-line compound multi-functional temperature/pressure sensor can be applied better to supervise the production of wood-based panels. All technical specifications of the compound multi-functional sensor were tested and the results met the requirements of the equipments.
文摘Vacuum insulation panels provide unprecedented possibilities for renovating the existing building stock in a manner that reduces the thermal losses through the building envelope. This study is focused on the implementation of VIPs （vacuum insulation panels） in energy retrofit projects with rendered outer walls. Particular emphasis is put on reducing the thermal bridges due to mechanical fasteners and at the joints of the panels. These are evaluated through a parametric study of the impact of the thermal conductivity of the joints of the panels and the adjacent insulation layer as well as the material of the fasteners. The study is carried out with 3D FEM （finite element method） simulations software. Furthermore, the moisture conditions in the construction are studied. The dynamic moisture behavior of a wall construction is modeled with a two dimensional FEM model. The long term effects of vapor diffusion are investigated in terms of accumulated moisture and the risk of condensation. The results illustrate that vacuum insulation on the outside of the wall construction does not pose a moisture problem to the construction. The simulations are based on a draft of a new technical solution for the refurbishment of a building that is typical for the great Swedish building program of the 1970s.
基金supported by the National Natural Science Foundation of China general Projects(No.51174193)the Youth Fund Project of the National Natural Science Foundation of China(No.51004102)the National High Technology Research and Development Program of China(No.2012AA062101)
文摘This paper proposes the concept of projection curves based on the theory of CT image reconstruction to probe the internal structure of the working panel prior to formal mining of the working panel.As well as reducing costs,this method provides safe and efficient excavation of the working panel.According to the results of the numerical model and the actual working panel,the new method has been proven to be accurate in detecting the location of the fault that extends into the face.Concealed faults of the internal working panel,as well as the start and end points of the fault,can be detected by this method.Engineering practice has proven that the method is highly reliable,has a highly decisive impact on faults for coal mining,and can be used to guide the safe mining of the working panel.
文摘Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry.In this study,a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of ply-wood.The preparation technique of plywood was optimized,and the chemical structure,curing performance,crystallization property and thermal performance of the adhesive were investigated.Results showed that:(1)hot-pressing temperature played a decisive role in the performances of tannin-sucrose composite adhesives and it also had a very significant influence on the water resistance of plywood.(2)The preparation of tannin-sucrose composite adhesive was a process in which sucrose was transformed into furan aldehydes and then made cross-linking reaction with tannin.These composite adhesives could only get good bonding performances when the curing temperature was above 210℃.(3)The optimal plywood preparation technique was:hot-pressing tem-perature of 220℃,hot-pressing time of 1.2 min/mm,m(tannin):m(sucrose)of 60:40,and adhesive loading of 160 g/m^(2).The wet bonding strength in boiling water of the prepared plywood was 0.83 MPa,meeting the strength requirements of Type-I plywood in the standard of GB/T 17657-2013.(4)The curing temperature of tannin-sucrose composite adhesive was further decreased by lowering the temperature during the transformation of sucrose into 5-HMF,which was a key in subsequent research.
文摘The production of wood-based panel was presented firstly in this paper. Some features of China’s wood-based panel industry were reviewed, including production bases, raw materials and main markets of wood-based panel. In addition, the trade flow of wood-based panel was described in the end.
