A method utilizing variable depth increments during incremental forming was proposed and then optimized based on numerical simulation and intelligent algorithm.Initially,a finite element method(FEM) model was set up a...A method utilizing variable depth increments during incremental forming was proposed and then optimized based on numerical simulation and intelligent algorithm.Initially,a finite element method(FEM) model was set up and then experimentally verified.And the relation between depth increment and the minimum thickness tmin as well as its location was analyzed through the FEM model.Afterwards,the variation of depth increments was defined.The designed part was divided into three areas according to the main deformation mechanism,with Di(i=1,2) representing the two dividing locations.And three different values of depth increment,Δzi(i=1,2,3) were utilized for the three areas,respectively.Additionally,an orthogonal test was established to research the relation between the five process parameters(D and Δz) and tmin as well as its location.The result shows that Δz2 has the most significant influence on the thickness distribution for the corresponding area is the largest one.Finally,a single evaluating indicator,taking into account of both tmin and its location,was formatted with a linear weighted model.And the process parameters were optimized through a genetic algorithm integrated with an artificial neural network based on the evaluating index.The result shows that the proposed algorithm is satisfactory for the optimization of variable depth increment.展开更多
Formwork construction has been the important and difficult of the construction process, so the design plan is very important. This paper relies on the Shun Ping Yu subordinate Fertgbo bridge rebuilding project, detail...Formwork construction has been the important and difficult of the construction process, so the design plan is very important. This paper relies on the Shun Ping Yu subordinate Fertgbo bridge rebuilding project, detailing the cast-in-place box beam formwork support system safety special construction plan, focuses on box girder formwork design scheme of foundation design, box girder bracket design and box girder formwork design, to provide a reasonable reference for similar projects.展开更多
Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in util...Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in utilizing the technology of gob-side entry retaining in steep coal seams is to safely and effectively prevent caving rock blocks from rushing into the gob-side entry by sliding downwards along levels. Using theoretical analysis and field methods, we numerically simulated the mining process on a fully-mechanized face in a steep coal seam. The stress and deformation process of roof strata has been analyzed, and the difficulty of utilizing the technology is considered and combined with practice in a steep working face in Lvshuidong mine. The feasibility of utilizing the technology of gob-side entry retaining in a steep coal seam has been recognised. We propose that roadways along the left lane offshoot body use a speciallymade reinforced steel dense net to build a dense rock face at the lower head. The results show that the lane offshoot branch creates effective roof control, safe conditions for roadway construction workers, and practical application of steeply inclined gob.展开更多
Against the background of analyzing coal wall stability in 14101 fully mechanized longwall top coal caving face in Majialiang coal mine,based on the torque equilibrium of the coal wall,shield support and the roof stra...Against the background of analyzing coal wall stability in 14101 fully mechanized longwall top coal caving face in Majialiang coal mine,based on the torque equilibrium of the coal wall,shield support and the roof strata,an elastic mechanics model was established to calculate the stress applied on the coal wall.The displacement method was used to obtain the stress and deformation distributions of the coal wall.This study also researched the influence of support resistance,protective pressure to the coal wall,fracture position of the main roof and mining height on the coal wall deformation.The following conclusions are drawn:(1) The shorter the distance from the longwall face,the greater the vertical compressive stress and horizontal tensile stress borne by the coal wall.The coal wall is prone to failure in the form of compressive-shear and tension;(2) With increasing support resistance,the revolution angle of the main roof decreases linearly.As the support resistance and protective force supplied by the face guard increases,the maximum deformation of the coal wall decreases linearly;(3) As the face approaches the fracture position of the main roof,coal wall horizontal deformation increases significantly,and the coal wall is prone to instability;and(4) The best mining height of 14101 longwall face is 3.0 m.展开更多
[Objective] The aims was to construct peak sweet processing suitability evaluation model and determine the suitable varieties of peak sweet processing in chestnut. [Method] ＂Zaofeng＂, ＂Yah Long＂ etc. 15 chestnut v...[Objective] The aims was to construct peak sweet processing suitability evaluation model and determine the suitable varieties of peak sweet processing in chestnut. [Method] ＂Zaofeng＂, ＂Yah Long＂ etc. 15 chestnut varieties in Yan Shan area were taken as research objects and investigated the sensory, physicochemical nutrition and processing indexes. The correlation analysis, principal component analysis and cluster analysis were adopted to simplify and calculate the evaluation index, and set up the mathematical model. [Result] Obvious differences in different varieties of raw materials and products of each index and some indicators existed significant correlation relationship; principal component analysis determined the five principal components： hardness, b value, moisture content, total sugar, browning degree and edible rate or the core indicators of quality evaluation in peak sweet chestnut, and the establishment of products comprehensive value scoring model： Y=0.033 509 hardness ＋0.033 509 b value ＋0.f85 1＇73 moisture content ＋0.208 983 total sugar ＋0.108 499 browning degree ＋0.430 327 ratio of feed, peak sweet chestnut quality and raw material associated model： Y=-1.109＋0.015 ratio of good fruit -0.018 kernel hardness ＋0.008 starch, [Conclusion] Peak sweet chestnut processing suitability evaluation model can provide the basis for chestnut processing and the suitable processing of the chestnut breeding; ＂Yanguang＂, ＂Yan Long＂, ＂Yankui＂, are very suitable, and ＂Zibo＂, ＂Yah Ping＂ are more appropriate for peak sweet processing.展开更多
Objective： To develop a novel method of spinal pedical stereotaxy by reverse engineering and rapid prototyping techniques, and to validate its accuracy by experimental and clinical studies. Methods： A 3D reconstruc...Objective： To develop a novel method of spinal pedical stereotaxy by reverse engineering and rapid prototyping techniques, and to validate its accuracy by experimental and clinical studies. Methods： A 3D reconstruction model for the desired lumbar vertebra was generated by using the Mimics 10.11 software, and the optimal screw size and orientation were determined using the reverse engineering software. Afterwards, a drill template was created by reverse engineering principle, whose surface was the antitemplate of the vertebral surface. The drill template and its corresponding vertebra were manufactured using the rapid prototyping technique. Results： The accuracy of the drill template was confinned by drilling screw trajectory into the vertebral biomodel preoperatively. This method also showed its ability to customize the placement and size of each screw based on the unique morphology of the lumbar vertebra.The drill template fits the postural surface of the vertebra very well in the cadaver experiment. Postoperative CT scans for controlling the pedicle bore showed that the personalized template had a high precision in cadaver experiment and clinical application. No misplacement occurred by using the personalized template. During surgery, no additional computer assistance was needed. Conclusions： The authors have developed a novel drill template for lumbar pedicle screw placement with good applicability and high accuracy. The potential use of drill templates to place lumbar pedicle screws is promising, Our methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the lumbar spine.展开更多
Objective： To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique. Methods： Pelvis image data were obtained from threedimensional C...Objective： To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique. Methods： Pelvis image data were obtained from threedimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The threedimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the threedimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction （total reduction, half reduction and non-reduction） were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws. Results： Accurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate. Conclusion： The navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.展开更多
文摘A method utilizing variable depth increments during incremental forming was proposed and then optimized based on numerical simulation and intelligent algorithm.Initially,a finite element method(FEM) model was set up and then experimentally verified.And the relation between depth increment and the minimum thickness tmin as well as its location was analyzed through the FEM model.Afterwards,the variation of depth increments was defined.The designed part was divided into three areas according to the main deformation mechanism,with Di(i=1,2) representing the two dividing locations.And three different values of depth increment,Δzi(i=1,2,3) were utilized for the three areas,respectively.Additionally,an orthogonal test was established to research the relation between the five process parameters(D and Δz) and tmin as well as its location.The result shows that Δz2 has the most significant influence on the thickness distribution for the corresponding area is the largest one.Finally,a single evaluating indicator,taking into account of both tmin and its location,was formatted with a linear weighted model.And the process parameters were optimized through a genetic algorithm integrated with an artificial neural network based on the evaluating index.The result shows that the proposed algorithm is satisfactory for the optimization of variable depth increment.
文摘Formwork construction has been the important and difficult of the construction process, so the design plan is very important. This paper relies on the Shun Ping Yu subordinate Fertgbo bridge rebuilding project, detailing the cast-in-place box beam formwork support system safety special construction plan, focuses on box girder formwork design scheme of foundation design, box girder bracket design and box girder formwork design, to provide a reasonable reference for similar projects.
文摘Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in utilizing the technology of gob-side entry retaining in steep coal seams is to safely and effectively prevent caving rock blocks from rushing into the gob-side entry by sliding downwards along levels. Using theoretical analysis and field methods, we numerically simulated the mining process on a fully-mechanized face in a steep coal seam. The stress and deformation process of roof strata has been analyzed, and the difficulty of utilizing the technology is considered and combined with practice in a steep working face in Lvshuidong mine. The feasibility of utilizing the technology of gob-side entry retaining in a steep coal seam has been recognised. We propose that roadways along the left lane offshoot body use a speciallymade reinforced steel dense net to build a dense rock face at the lower head. The results show that the lane offshoot branch creates effective roof control, safe conditions for roadway construction workers, and practical application of steeply inclined gob.
基金provided by the Priority Academic Program Development of Jiangsu Higher Education Institutions,the Graduate Students of Jiangsu Province Innovation Program (No.CXZZ13_0948)the National Natural Science Foundation of China (No.51304202)the Natural Science Foundation of Jiangsu Province (No.BK20130190)
文摘Against the background of analyzing coal wall stability in 14101 fully mechanized longwall top coal caving face in Majialiang coal mine,based on the torque equilibrium of the coal wall,shield support and the roof strata,an elastic mechanics model was established to calculate the stress applied on the coal wall.The displacement method was used to obtain the stress and deformation distributions of the coal wall.This study also researched the influence of support resistance,protective pressure to the coal wall,fracture position of the main roof and mining height on the coal wall deformation.The following conclusions are drawn:(1) The shorter the distance from the longwall face,the greater the vertical compressive stress and horizontal tensile stress borne by the coal wall.The coal wall is prone to failure in the form of compressive-shear and tension;(2) With increasing support resistance,the revolution angle of the main roof decreases linearly.As the support resistance and protective force supplied by the face guard increases,the maximum deformation of the coal wall decreases linearly;(3) As the face approaches the fracture position of the main roof,coal wall horizontal deformation increases significantly,and the coal wall is prone to instability;and(4) The best mining height of 14101 longwall face is 3.0 m.
基金Supported by the Forestry Public Welfare Industry Research Special Fund Project of China(201304708)
文摘[Objective] The aims was to construct peak sweet processing suitability evaluation model and determine the suitable varieties of peak sweet processing in chestnut. [Method] ＂Zaofeng＂, ＂Yah Long＂ etc. 15 chestnut varieties in Yan Shan area were taken as research objects and investigated the sensory, physicochemical nutrition and processing indexes. The correlation analysis, principal component analysis and cluster analysis were adopted to simplify and calculate the evaluation index, and set up the mathematical model. [Result] Obvious differences in different varieties of raw materials and products of each index and some indicators existed significant correlation relationship; principal component analysis determined the five principal components： hardness, b value, moisture content, total sugar, browning degree and edible rate or the core indicators of quality evaluation in peak sweet chestnut, and the establishment of products comprehensive value scoring model： Y=0.033 509 hardness ＋0.033 509 b value ＋0.f85 1＇73 moisture content ＋0.208 983 total sugar ＋0.108 499 browning degree ＋0.430 327 ratio of feed, peak sweet chestnut quality and raw material associated model： Y=-1.109＋0.015 ratio of good fruit -0.018 kernel hardness ＋0.008 starch, [Conclusion] Peak sweet chestnut processing suitability evaluation model can provide the basis for chestnut processing and the suitable processing of the chestnut breeding; ＂Yanguang＂, ＂Yan Long＂, ＂Yankui＂, are very suitable, and ＂Zibo＂, ＂Yah Ping＂ are more appropriate for peak sweet processing.
基金This project was supported by China Postdoctoral Science Foundation （20080431420） and Yunnan Natural Science Foundation （2008CD210）.
文摘Objective： To develop a novel method of spinal pedical stereotaxy by reverse engineering and rapid prototyping techniques, and to validate its accuracy by experimental and clinical studies. Methods： A 3D reconstruction model for the desired lumbar vertebra was generated by using the Mimics 10.11 software, and the optimal screw size and orientation were determined using the reverse engineering software. Afterwards, a drill template was created by reverse engineering principle, whose surface was the antitemplate of the vertebral surface. The drill template and its corresponding vertebra were manufactured using the rapid prototyping technique. Results： The accuracy of the drill template was confinned by drilling screw trajectory into the vertebral biomodel preoperatively. This method also showed its ability to customize the placement and size of each screw based on the unique morphology of the lumbar vertebra.The drill template fits the postural surface of the vertebra very well in the cadaver experiment. Postoperative CT scans for controlling the pedicle bore showed that the personalized template had a high precision in cadaver experiment and clinical application. No misplacement occurred by using the personalized template. During surgery, no additional computer assistance was needed. Conclusions： The authors have developed a novel drill template for lumbar pedicle screw placement with good applicability and high accuracy. The potential use of drill templates to place lumbar pedicle screws is promising, Our methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the lumbar spine.
文摘Objective： To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique. Methods： Pelvis image data were obtained from threedimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The threedimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the threedimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction （total reduction, half reduction and non-reduction） were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws. Results： Accurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate. Conclusion： The navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.
