This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and t...This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and time-consuming computation. The two main parts of the presented methodology are 1) setting up a three-dimensional (3D) model to calculate the electric field based on combining ca- tenary equations with charge simulation method and 2) calculating the hybrid electric field excited by multi-circuit intersecting TLs using coordinate transformation and superposition technique. Examples of different TLs configurations, including a 220 kV single-circuit hori- zontally configured TLs, a 500 kV single-circuit triangularly configured TLs and a combination of the 220 kV TLs and the 550 kV TLs, are illustrated to verify the validity of this methodology. A more complicatal configurations, including a 500 kV double-circuit TLs and two 220 kV single-circuit horizontally configured TLs, are also calculated. Conclusions were drawn from the simulation: 1) The presented 3D model outperforms 2D models in describing the electric field distribution generated by practical HV TLs with sag and span. 2) Coordinate trans- formation and superposition technique considerably simplify the electric field computation for multi-circuit TLs configurations, which makes it possible to deal with complex engineering problems. 3) The electric field in the area covered by multiple intersecting overhead TLs is distorted and the hybrid electric field strength in some partial region increases so sharply that it might exceed the admissible value. 4) The configuration parameters of the TLs and the spatial configuration of multi-circuit TLs, for instance, the height of TLs, the length of span and the intersection angle of multiple circuits, influence the strength and the distribution of hybrid electric field. The influence regularities sum- marized in this paper can be referred by future TL designs to meet the electromagnetic environmental protection regulations.展开更多
To accurately analyze proppant transport in rough intersecting fractures and elucidate the interaction mechanisms among liquid,particles,and rough walls,this study reconstructed a numerical model of fractures in inhom...To accurately analyze proppant transport in rough intersecting fractures and elucidate the interaction mechanisms among liquid,particles,and rough walls,this study reconstructed a numerical model of fractures in inhomogeneous reservoirs with varying brittleness index(BI).Various auto-correlation Gaussian rough fracture models were created using Matlab to assess roughness through the fractal dimension method.This research innovatively combined Boolean operations to establish three-dimensional rough fracture models,incorporating(Computational Fluid Dynamics)CFD-DEM(Discrete Element Method)with a bidirectional method for cosimulation.The proppant transport in fractures was categorized into three zones based on the difference in the turbulent kinetic energy.Artificially induced fracture roughness increases fluid retention and turbulence,causing plugging effects and limiting proppant flow into branch fractures.Additionally,compared with the superior deposition and significant support effects of the spherical proppant,the low-sphericity proppant traveled farther under fracturing fluid,inducing more pronounced plugging near curved fracture intersections;the variation in fracture intersection angles primarily impacted the wall shear stress within the flow field,indicating smaller angles led to higher shear energy at the intersection.Compared with the intersection angle of 30°,the height and area deposited in the 90 branch fracture increased by 52.25%and 65.33%,respectively:notably,injecting proppant from smaller to larger particles(S:M:L)and a low velocity effectively ensured fracture conductivity near the wellbore at joint roughness coefficient(JRC)≥46 while achieving satis-factory placement in the branch fracture,making it a recommended approach.展开更多
Background: Wrist pain is prevalent. Activities such as dexterous sports, prolonged use of personal handheld devices, and extensive desktop keyboard usage are common contributors to wrist pain. Intersection syndrome, ...Background: Wrist pain is prevalent. Activities such as dexterous sports, prolonged use of personal handheld devices, and extensive desktop keyboard usage are common contributors to wrist pain. Intersection syndrome, a form of inflammatory tenosynovitis, occurs at the intersection of the first and second dorsal compartments of the wrist. The first dorsal compartment is comprised of the tendons of abductor pollicis longus and extensor pollicis brevis, while the second dorsal compartment contains the tendons of extensor carpi radialis longus and extensor carpi radialis brevis. Intersection syndrome is diagnosed by pain localized to the dorsoradial forearm, approximately five cm proximal to the wrist joint, which worsens with resisted wrist and thumb extension. To date, the use of hydro dissection with 5% dextrose under ultrasound guidance as a treatment for Intersection syndrome has not been reported. This case report presents the first report on ultrasound-guided hydro dissection as a therapeutic approach for intersection syndrome. Methods: A case report, with informed consent, involving a 32-year-old male athlete. The patient, a hurling player, presented with chronic right wrist pain diagnosed as intersection syndrome. The condition significantly affected his work, sporting activities, and daily living activities. Previous conservative management and physiotherapy had failed to alleviate his symptoms. To confirm the diagnosis, relevant imaging was performed, supplemented by dynamic ultrasound assessment. The procedure was performed aseptically. Continuous ultrasound guidance was employed to ensure accurate needle placement. Once the needle tip position was confirmed, an initial injection of 5 mL of 0.25% chirocaine was administered. 10 mL of 5% dextrose was injected under ultrasound guidance for hydro dissection, with good visualization of the solution’s distribution. Conclusion: Ultrasound-guided hydro dissection has not previously been documented as a treatment option for intersection syndrome. In this case, it proved to be an effective pain-relieving therapy with sustained effect at three-month clinical follow-up. Further studies are required.展开更多
In the next few years traffic will happen most of the time.This was triggered by the growing rate of vehicles against the road capacity which is not balance.All the time the congestion in the city of Semarang has occu...In the next few years traffic will happen most of the time.This was triggered by the growing rate of vehicles against the road capacity which is not balance.All the time the congestion in the city of Semarang has occured at peak hours.Congestion also occured in between Teuku Umar and Setia Budi road Jatingaleh because of a plot intersection(Kesatrian intersection,PLN intersection and Jatingaleh intersection)with the Toll Road.Jatingaleh is located in the southern city of Semarang which is a central meeting point between the upper and lower Semarang where the vehicle flows in through a combination of local current and regional traffic,and the flow of vehicles coming in and out from highway.The main cause of the problems that occurred in the area of Jatingaleh is due to the numbers of vehicles movement that occurs at the intersections.With the above issues,it is necessary to analyse the existing conditions and look into some solutions.Before carrying out an analysis a field surveys at peak hours for example morning(06:00 to 08:00 am)and for the afternoon(04:00 to 06:00 pm)should be conducted,then the number of vehicles is counted manually with“short-breakcounting”according to types of vehicles.From the analysis we found that the degree of saturation(DS)is 1.61 between Teuku Umar and Setia Budi road during the morning peak hours and 1.56 during the afternoon peak hours.This means that the capacity of the existing road is no longer able to accommodate the traffic flow.One of the solutions for the congestion that occurs at the intersection of Jatingaleh is to apply the efficiency of the intersection that is not in a plot with a Fly over,Underpass and the combination of Fly Over-Underpass.Base on the flow reduction calculation with 3 comparative modeling it shows that the Fly Over is the most technically efficient to be applied in this research.展开更多
This article explores the intersections of Buddhism,Daoism,and contemporary French literary practice in the study of the everyday(quotidien).Since the 1980s,French literature has increasingly shifted its focus from th...This article explores the intersections of Buddhism,Daoism,and contemporary French literary practice in the study of the everyday(quotidien).Since the 1980s,French literature has increasingly shifted its focus from the exotic to the mundane,engaging with theoretical frameworks developed by scholars such as Henri Lefebvre and Michel de Certeau.Drawing on Buddhist notions of emptiness and dependent arising,as well as Daoist principles of yin-yang interdependence,the article bridges Eastern and Western philosophies to demonstrate the everyday not as a static or trivial backdrop,but as a dynamic and transformative space.It further examines how representations of daily life in the works of Georges Perec and Jacques Roubaud employ the meticulous documentation of mundane details to uncover hidden patterns,rhythms,and structures of human experience.Through literary fieldwork,Perec and Roubaud challenge conventional perceptions of the everyday,unveiling its depth,complexity,and potential for reinvention.展开更多
The intersection is a widely used traffic line structure from the shallow tunnel to the deep roadway,and determining the subsidence hidden danger area of the roof is the key to its stability control.However,applying t...The intersection is a widely used traffic line structure from the shallow tunnel to the deep roadway,and determining the subsidence hidden danger area of the roof is the key to its stability control.However,applying traditional maximum equivalent span beam(MESB)theory to determine deformation range,peak point,and angle influence poses a challenge.Considering the overall structure of the intersection roof,the maximum equivalent triangular plate(METP)theory is proposed,and its geometric parameter calculation formula and deflection calculation formula are obtained.The application of the two theories in 18 models with different intersection angles,roadway types,and surrounding rock lithology is verified by numerical analysis.The results show that:1)The METP structure of the intersection roof established by the simulation results of each model successfully determined the location of the roof’s high displacement zone;2)The area comparison method of the METP theory can be reasonably explained:①The roof subsidence of the intersection decreases with the increase of the intersection angle;②The roof subsidence at the intersection of different roadway types has a rectangular type>arch type>circular type;③The roof subsidence of the intersection with weak surrounding rock is significantly larger than that of the intersection with hard surrounding rock.According to the application results of the two theories,the four advantages of the METP theory are compared and clarified in the basic assumptions,mechanical models,main viewpoints,and mechanism analysis.The large deformation inducement of the intersection roof is then explored.The J 2 peak area of the roof drives the large deformation of the area,the peak point of which is consistent with the center of gravity position of the METP.Furthermore,the change in the range of this peak is consistent with the change law of the METP’s area.Hence,this theory clarifies the large deformation area of the intersection roof,which provides a clear guiding basis for its initial support design,mid-term monitoring,and late local reinforcement.展开更多
In this paper,we introduce the normalized L,mixed intersection body and demonstrate how the normalized L_(p) mixed intersection body operator can be used to obtain the polar body operator as a limit.Moreover,we study ...In this paper,we introduce the normalized L,mixed intersection body and demonstrate how the normalized L_(p) mixed intersection body operator can be used to obtain the polar body operator as a limit.Moreover,we study the L_(p)-Busemann-Petty type problem for the normalized L_(p) mixed intersection bodies.展开更多
All-position robots are widely applied in the welding of complicated parts.Welding of intersecting pipes is one of the most typical tasks.The welding seam is a complicated saddle-like space curve,which puts a great ch...All-position robots are widely applied in the welding of complicated parts.Welding of intersecting pipes is one of the most typical tasks.The welding seam is a complicated saddle-like space curve,which puts a great challenge to the pose planning of end-effector.The special robots designed specifically for this kind of tasks are rare in China and lack sufficient theoretical research.In this paper,a systematic research on the pose planning for the end-effectors of robot in the welding of intersecting pipes is conducted. First,the intersecting curve of pipes is mathematically analyzed.The mathematical model of the most general intersecting curve of pipes is derived,and several special forms of this model in degraded situations are also discussed.A new pose planning approach of bisecting angle in main normal plane（BAMNP） for the welding-gun is proposed by using differential geometry and the comparison with the traditional bisecting angle in axial rotation plane（BAARP） method is also analytically conducted.The optimal pose of the welding-gun is to make the orientation posed at the center of the small space formed by the two cylinders and the intersecting curve to help the welding-pool run smoothly.The BAMNP method can make sure the pose vertical to the curve and center between the two cylinders at the same time,therefore its performance in welding-technique is superior to the BAARP method.By using the traditional BAARP method,the robot structure can become simpler and easier to be controlled,because one degree of freedom（DOF） of the robot can be reduced.For the special case of perpendicular intersecting,an index is constructed to evaluate the quality of welding technique in the process of welding.The effect of different combination of pipe size on this index is also discussed.On the basis of practical consideration,selection principle for BAARP and BAMNP is described.The simulations of those two methods for a serial joint-type robot are made in MATLAB,and the simulation results are consistent to the analysis.The mathematical model and the proposed new pose-planning method will lay a solid foundation for future researches on the control and design of all-position welding robots.展开更多
Predicting rock cracking is important for assessing the stability of underground engineering.The effects of the intersecting angle a and the distribution orientation angleβof intersecting fissures on the uniaxial com...Predicting rock cracking is important for assessing the stability of underground engineering.The effects of the intersecting angle a and the distribution orientation angleβof intersecting fissures on the uniaxial compressive strength and the failure characteristics of sandstone containing intersecting fissures are investigated through laboratory experiments and two-dimensional particle flow code(PFC2D).The relationship between the mechanical properties of sandstone and the intersecting angle a and the distribution orientation angleβis analysed.Crack initiation forms and the final failure modes are then categorised and determined via empirical methods.In addition,the cracking processes of intersecting fissures with different a andβvalues are discussed.The results show that variations in the peak stress,peak strain,average modulus,and crack initiation stress of sandstone containing intersecting fissures show a“moth”shape in the space of the a-β-mechanical parameters.Two crack initiation forms are identified:inner tip cracking(usually accompanied by one outer tip cracking)and only outer tips cracking.Two failure modes are observed:(1)the main fracture planes are created at the inner tip and one outer tip,and(2)the main fracture planes are formed at the two outer tips.Two main crack evolution processes of sandstone containing intersecting fissures under uniaxial compression are found.Approaches for quickly determining the crack initiation form and the failure mode are proposed.The combination of the determination equations for the crack initiation form and the failure mode can be used to predict the crack evolution.The approach for determining the crack evolution processes is hence proposed with acceptable precision.展开更多
We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Th...We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Then, the smoothly blending of two cylinders whose axes are non-coplanar is realized by taking intersecting line of conical surface as axes.展开更多
This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal forming.The devel...This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal forming.The developed methodology has three major steps:subdivision of B-spline surfaces,detection of protrusions and depressions,and recognition of geometric features for sheet metal forming domain.The input geometry data format of the part is based on an IGES CAD surface model represented in the form of trimmed B-spline surfaces.Each surface is classified or subdivided into different curvature regions with the aid of curvature property surfaces obtained by using symbolic computation of B-spline surfaces.Those regions satisfying a particular geometry and topology relation are recognized as protrusion and depression(DP) shapes.The DP shapes are then classified into different geometric features using a rule-based approach.A verified feasibility study of the developed method is also presented.展开更多
This paper focuses on the simulation analysis of stripe formation and dynamic features of intersecting pedestrian flows.The intersecting flows consist of two streams of pedestrians and each pedestrian stream has a des...This paper focuses on the simulation analysis of stripe formation and dynamic features of intersecting pedestrian flows.The intersecting flows consist of two streams of pedestrians and each pedestrian stream has a desired walking direction.The model adopted in the simulations is the social force model, which can reproduce the self-organization phenomena successfully. Three scenarios of different cross angles are established. The simulations confirm the empirical observations that there is a stripe formation when two streams of pedestrians intersect and the direction of the stripes is perpendicular to the sum of the directional vectors of the two streams. It can be concluded from the numerical simulation results that smaller cross angle results in higher mean speed and lower level of speed fluctuation. Moreover, the detailed pictures of pedestrians＇ moving behavior at intersections are given as well.展开更多
We investigate the construction of four-family N= 1 supersymmetric Pati-Salam models from Type IIA T^(6)×Z_(2) Z_(2) orientifold with intersecting D6-branes. Utilizing the deterministic algorithm introduced in He...We investigate the construction of four-family N= 1 supersymmetric Pati-Salam models from Type IIA T^(6)×Z_(2) Z_(2) orientifold with intersecting D6-branes. Utilizing the deterministic algorithm introduced in He W, Li T and Sun R(2021 ar Xiv: hep-th/2112.09632), we obtain 274 types of models with three rectangular tori and distinct gauge coupling relations at string scale,while 6 types of models with two rectangular tori and one tilted torus. In both cases, there exists a class of models with gauge coupling unification at string scale. In particular, for the models with two rectangular tori, one tilted torus and gauge coupling unification, the gaugino condensations are allowed, and thus supersymmetry breaking and moduli stabilization are possible for further phenomenological study.展开更多
Let Cnk denote the set of all t -subsets of an n -set. Assume A ∈ Cnk and B∈Cn.b (A,B) is called a cross-2-intersecting family if |A∩B|≥2 for any A∈A, B∈B.In this paper, the best upper bounds of the cardinalitie...Let Cnk denote the set of all t -subsets of an n -set. Assume A ∈ Cnk and B∈Cn.b (A,B) is called a cross-2-intersecting family if |A∩B|≥2 for any A∈A, B∈B.In this paper, the best upper bounds of the cardinalities for non-empty cross-2-intersecting families of a- and i- subsets are obtained for some n and b . A new proof for a Frankl-Tokushige theorem [6] is also given.展开更多
To improve the hit probability of tank at high speed,a prediction method of projectile-target intersection based on adaptive robust constraint-following control and interval uncertainty analysis is proposed.The method...To improve the hit probability of tank at high speed,a prediction method of projectile-target intersection based on adaptive robust constraint-following control and interval uncertainty analysis is proposed.The method proposed provides a novel way to predict the impact point of projectile for moving tank.First,bidirectional stability constraints and stability constraint-following error are constructed using the Udwadia-Kalaba theory,and an adaptive robust constraint-following controller is designed considering uncertainties.Second,the exterior ballistic ordinary differential equation with uncertainties is integrated into the controller,and the pointing control of stability system is extended to the impact-point control of projectile.Third,based on the interval uncertainty analysis method combining Chebyshev polynomial expansion and affine arithmetic,a prediction method of projectile-target intersection is proposed.Finally,the co-simulation experiment is performed by establishing the multi-body system dynamic model of tank and mathematical model of control system.The results demonstrate that the prediction method of projectile-target intersection based on uncertainty analysis can effectively decrease the uncertainties of system,improve the prediction accuracy,and increase the hit probability.The adaptive robust constraint-following control can effectively restrain the uncertainties caused by road excitation and model error.展开更多
Dynamic recrystallization(DRX)is of great significance for the thermomechanical processing and microstructural regulation of TiAl intermetallics.However,the underlying DRX mechanism remains poorly understood.In this s...Dynamic recrystallization(DRX)is of great significance for the thermomechanical processing and microstructural regulation of TiAl intermetallics.However,the underlying DRX mechanism remains poorly understood.In this study,an Avrami kinetics model for DRX was established,which was capable of predicting the DRX fraction accurately.In addition,the effect of Al_(2)O_(3)short fiber on the DRX mechanisms of TiAl matrix composite during the isothermal compression was investigated for the first time.The re-sults showed that other than inhibiting DRX by particles in the TiAl matrix composites,the addition of Al_(2)O_(3)short fiber accelerated a novel DRX process,which was induced by twinning and twin intersec-tions(TDRX).Thus,this composite exhibited a higher DRX rate than that of the as-cast TiAl monolithic alloy.The origin of the twin intersection and TDRX for the composite was revealed.The stress concentration near the Al_(2)O_(3)fiber was above the critical shear stress for twinning and thus was favorable for the formation of twinning and twin intersections.The high stored strain energy at the regions of twins and twin intersections provided the driving force for TDRX.TDRX accelerated the grain refinement in the TiAl matrix near the Al_(2)O_(3)fiber.The present findings would provide a new perspective on DRX mechanisms,and provide the scientific guidance for optimizing the microstructures of TiAl matrix composites.展开更多
This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of elect...This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of electron backscattered diffraction investigations showed that the activated twins were primarily{1012}tension twins,and 60°<1010>boundaries formed due to twin–twin intersections under different strain rates.Isolated twin variants with 60°<1010>boundaries transformed into new grains through lattice rotations at a low strain rate(0.01 s^(−1)).At a high strain rate(10 s^(−1)),the regions surrounded by subgrain boundaries through high-density dislocation arrangement and the 60°<1010>boundaries transformed into new grains via dynamic recrystallization.展开更多
The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the anal...The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the analytic expression of them. Finally, with computer programming language, it gives a program to generate the intersection in several different cases.展开更多
The celebrated Erdos-Ko-Rado theorem states that given n≥2k,every intersecting k-uni-n-1 form hypergraph G on n vertices has at most(n-1 k-1)edges.This paper states spectral versions of the Erd6s-_Ko--Rado theorem:le...The celebrated Erdos-Ko-Rado theorem states that given n≥2k,every intersecting k-uni-n-1 form hypergraph G on n vertices has at most(n-1 k-1)edges.This paper states spectral versions of the Erd6s-_Ko--Rado theorem:let G be an intersecting k-uniform hypergraph on n vertices with n≥2k.Then,the sharp upper bounds for the spectral radius of Aα(G)and 2*(G)are presented,where Aα(G)=αD(G)+(1-α).A(G)is a convex linear combination of the degree diagonal tensor D(G)and the adjacency tensor A(G)for 0≤α<1,and Q^(*)(G)is the incidence Q-tensor,respectively.Furthermore,when n>2k,the extremal hypergraphs which attain the sharp upper bounds are characterized.The proof mainly relies on the Perron-Frobenius theorem for nonnegative tensor and the property of the maximizing connected hypergraphs.展开更多
In order to establish the groove model for intersecting structures of circular tubes,mathematical model of the intersecting line is established by the method of analytic geometry,and parametric equations are thus dete...In order to establish the groove model for intersecting structures of circular tubes,mathematical model of the intersecting line is established by the method of analytic geometry,and parametric equations are thus determined.The dihedral angle,groove angle and actual cutting angle for any position of the intersecting line are derived as well.In order to identify groove vectors for two pipes,a new analytical method,i.e.coplanarity of vectors,is further proposed to complete the groove model.The established model is virtually verified by programming and simulation calculation in the MATLAB environment.The results show that groove vectors of intersecting structures simulated by MATLAB are consistent with the theoretical groove model,indicating that the theoretical groove model established in this paper is accurate,and further proves that the proposed coplanarity of vectors for solving groove vectors is correct and feasible.Finally,a graphical user interface(GUI)is developed by MATLAB software to independently realize functions such as model drawing,variable calculation and data output.The research outcome provides a theoretical foundation for the actual welding of circular intersecting structures,and lays an essential basis for weld bead layout and path planning.展开更多
基金Project supported by Scientific Research Foundation of State Key Laboratory of Power Transmission Equipment ＆ System Security and New Technology （2007DA1051271 2204）, Natural Science Foundation of Chongqing Municipality （cstc201 ljjA20009）.
文摘This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and time-consuming computation. The two main parts of the presented methodology are 1) setting up a three-dimensional (3D) model to calculate the electric field based on combining ca- tenary equations with charge simulation method and 2) calculating the hybrid electric field excited by multi-circuit intersecting TLs using coordinate transformation and superposition technique. Examples of different TLs configurations, including a 220 kV single-circuit hori- zontally configured TLs, a 500 kV single-circuit triangularly configured TLs and a combination of the 220 kV TLs and the 550 kV TLs, are illustrated to verify the validity of this methodology. A more complicatal configurations, including a 500 kV double-circuit TLs and two 220 kV single-circuit horizontally configured TLs, are also calculated. Conclusions were drawn from the simulation: 1) The presented 3D model outperforms 2D models in describing the electric field distribution generated by practical HV TLs with sag and span. 2) Coordinate trans- formation and superposition technique considerably simplify the electric field computation for multi-circuit TLs configurations, which makes it possible to deal with complex engineering problems. 3) The electric field in the area covered by multiple intersecting overhead TLs is distorted and the hybrid electric field strength in some partial region increases so sharply that it might exceed the admissible value. 4) The configuration parameters of the TLs and the spatial configuration of multi-circuit TLs, for instance, the height of TLs, the length of span and the intersection angle of multiple circuits, influence the strength and the distribution of hybrid electric field. The influence regularities sum- marized in this paper can be referred by future TL designs to meet the electromagnetic environmental protection regulations.
文摘To accurately analyze proppant transport in rough intersecting fractures and elucidate the interaction mechanisms among liquid,particles,and rough walls,this study reconstructed a numerical model of fractures in inhomogeneous reservoirs with varying brittleness index(BI).Various auto-correlation Gaussian rough fracture models were created using Matlab to assess roughness through the fractal dimension method.This research innovatively combined Boolean operations to establish three-dimensional rough fracture models,incorporating(Computational Fluid Dynamics)CFD-DEM(Discrete Element Method)with a bidirectional method for cosimulation.The proppant transport in fractures was categorized into three zones based on the difference in the turbulent kinetic energy.Artificially induced fracture roughness increases fluid retention and turbulence,causing plugging effects and limiting proppant flow into branch fractures.Additionally,compared with the superior deposition and significant support effects of the spherical proppant,the low-sphericity proppant traveled farther under fracturing fluid,inducing more pronounced plugging near curved fracture intersections;the variation in fracture intersection angles primarily impacted the wall shear stress within the flow field,indicating smaller angles led to higher shear energy at the intersection.Compared with the intersection angle of 30°,the height and area deposited in the 90 branch fracture increased by 52.25%and 65.33%,respectively:notably,injecting proppant from smaller to larger particles(S:M:L)and a low velocity effectively ensured fracture conductivity near the wellbore at joint roughness coefficient(JRC)≥46 while achieving satis-factory placement in the branch fracture,making it a recommended approach.
文摘Background: Wrist pain is prevalent. Activities such as dexterous sports, prolonged use of personal handheld devices, and extensive desktop keyboard usage are common contributors to wrist pain. Intersection syndrome, a form of inflammatory tenosynovitis, occurs at the intersection of the first and second dorsal compartments of the wrist. The first dorsal compartment is comprised of the tendons of abductor pollicis longus and extensor pollicis brevis, while the second dorsal compartment contains the tendons of extensor carpi radialis longus and extensor carpi radialis brevis. Intersection syndrome is diagnosed by pain localized to the dorsoradial forearm, approximately five cm proximal to the wrist joint, which worsens with resisted wrist and thumb extension. To date, the use of hydro dissection with 5% dextrose under ultrasound guidance as a treatment for Intersection syndrome has not been reported. This case report presents the first report on ultrasound-guided hydro dissection as a therapeutic approach for intersection syndrome. Methods: A case report, with informed consent, involving a 32-year-old male athlete. The patient, a hurling player, presented with chronic right wrist pain diagnosed as intersection syndrome. The condition significantly affected his work, sporting activities, and daily living activities. Previous conservative management and physiotherapy had failed to alleviate his symptoms. To confirm the diagnosis, relevant imaging was performed, supplemented by dynamic ultrasound assessment. The procedure was performed aseptically. Continuous ultrasound guidance was employed to ensure accurate needle placement. Once the needle tip position was confirmed, an initial injection of 5 mL of 0.25% chirocaine was administered. 10 mL of 5% dextrose was injected under ultrasound guidance for hydro dissection, with good visualization of the solution’s distribution. Conclusion: Ultrasound-guided hydro dissection has not previously been documented as a treatment option for intersection syndrome. In this case, it proved to be an effective pain-relieving therapy with sustained effect at three-month clinical follow-up. Further studies are required.
文摘In the next few years traffic will happen most of the time.This was triggered by the growing rate of vehicles against the road capacity which is not balance.All the time the congestion in the city of Semarang has occured at peak hours.Congestion also occured in between Teuku Umar and Setia Budi road Jatingaleh because of a plot intersection(Kesatrian intersection,PLN intersection and Jatingaleh intersection)with the Toll Road.Jatingaleh is located in the southern city of Semarang which is a central meeting point between the upper and lower Semarang where the vehicle flows in through a combination of local current and regional traffic,and the flow of vehicles coming in and out from highway.The main cause of the problems that occurred in the area of Jatingaleh is due to the numbers of vehicles movement that occurs at the intersections.With the above issues,it is necessary to analyse the existing conditions and look into some solutions.Before carrying out an analysis a field surveys at peak hours for example morning(06:00 to 08:00 am)and for the afternoon(04:00 to 06:00 pm)should be conducted,then the number of vehicles is counted manually with“short-breakcounting”according to types of vehicles.From the analysis we found that the degree of saturation(DS)is 1.61 between Teuku Umar and Setia Budi road during the morning peak hours and 1.56 during the afternoon peak hours.This means that the capacity of the existing road is no longer able to accommodate the traffic flow.One of the solutions for the congestion that occurs at the intersection of Jatingaleh is to apply the efficiency of the intersection that is not in a plot with a Fly over,Underpass and the combination of Fly Over-Underpass.Base on the flow reduction calculation with 3 comparative modeling it shows that the Fly Over is the most technically efficient to be applied in this research.
基金funded by Sichuan International Studies University within the framework of the research project“Oulipian Experimentalism and Spatial Structure in the Travel Narratives of Jacques Roubaud”(sisu202008).
文摘This article explores the intersections of Buddhism,Daoism,and contemporary French literary practice in the study of the everyday(quotidien).Since the 1980s,French literature has increasingly shifted its focus from the exotic to the mundane,engaging with theoretical frameworks developed by scholars such as Henri Lefebvre and Michel de Certeau.Drawing on Buddhist notions of emptiness and dependent arising,as well as Daoist principles of yin-yang interdependence,the article bridges Eastern and Western philosophies to demonstrate the everyday not as a static or trivial backdrop,but as a dynamic and transformative space.It further examines how representations of daily life in the works of Georges Perec and Jacques Roubaud employ the meticulous documentation of mundane details to uncover hidden patterns,rhythms,and structures of human experience.Through literary fieldwork,Perec and Roubaud challenge conventional perceptions of the everyday,unveiling its depth,complexity,and potential for reinvention.
基金Project(52204164)supported by the National Natural Science Foundation of ChinaProject(2021QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,China。
文摘The intersection is a widely used traffic line structure from the shallow tunnel to the deep roadway,and determining the subsidence hidden danger area of the roof is the key to its stability control.However,applying traditional maximum equivalent span beam(MESB)theory to determine deformation range,peak point,and angle influence poses a challenge.Considering the overall structure of the intersection roof,the maximum equivalent triangular plate(METP)theory is proposed,and its geometric parameter calculation formula and deflection calculation formula are obtained.The application of the two theories in 18 models with different intersection angles,roadway types,and surrounding rock lithology is verified by numerical analysis.The results show that:1)The METP structure of the intersection roof established by the simulation results of each model successfully determined the location of the roof’s high displacement zone;2)The area comparison method of the METP theory can be reasonably explained:①The roof subsidence of the intersection decreases with the increase of the intersection angle;②The roof subsidence at the intersection of different roadway types has a rectangular type>arch type>circular type;③The roof subsidence of the intersection with weak surrounding rock is significantly larger than that of the intersection with hard surrounding rock.According to the application results of the two theories,the four advantages of the METP theory are compared and clarified in the basic assumptions,mechanical models,main viewpoints,and mechanism analysis.The large deformation inducement of the intersection roof is then explored.The J 2 peak area of the roof drives the large deformation of the area,the peak point of which is consistent with the center of gravity position of the METP.Furthermore,the change in the range of this peak is consistent with the change law of the METP’s area.Hence,this theory clarifies the large deformation area of the intersection roof,which provides a clear guiding basis for its initial support design,mid-term monitoring,and late local reinforcement.
基金Supported by the Postgraduate Scientific Research Innovation Project of Hunan Province (CX20231033)。
文摘In this paper,we introduce the normalized L,mixed intersection body and demonstrate how the normalized L_(p) mixed intersection body operator can be used to obtain the polar body operator as a limit.Moreover,we study the L_(p)-Busemann-Petty type problem for the normalized L_(p) mixed intersection bodies.
基金supported by National Nautural Science Foundation of China(Grant No.50775002)Key Science and Technology Research Program of Beijing Municipal Commission of Education of China(Grant No.KZ200910005003)
文摘All-position robots are widely applied in the welding of complicated parts.Welding of intersecting pipes is one of the most typical tasks.The welding seam is a complicated saddle-like space curve,which puts a great challenge to the pose planning of end-effector.The special robots designed specifically for this kind of tasks are rare in China and lack sufficient theoretical research.In this paper,a systematic research on the pose planning for the end-effectors of robot in the welding of intersecting pipes is conducted. First,the intersecting curve of pipes is mathematically analyzed.The mathematical model of the most general intersecting curve of pipes is derived,and several special forms of this model in degraded situations are also discussed.A new pose planning approach of bisecting angle in main normal plane（BAMNP） for the welding-gun is proposed by using differential geometry and the comparison with the traditional bisecting angle in axial rotation plane（BAARP） method is also analytically conducted.The optimal pose of the welding-gun is to make the orientation posed at the center of the small space formed by the two cylinders and the intersecting curve to help the welding-pool run smoothly.The BAMNP method can make sure the pose vertical to the curve and center between the two cylinders at the same time,therefore its performance in welding-technique is superior to the BAARP method.By using the traditional BAARP method,the robot structure can become simpler and easier to be controlled,because one degree of freedom（DOF） of the robot can be reduced.For the special case of perpendicular intersecting,an index is constructed to evaluate the quality of welding technique in the process of welding.The effect of different combination of pipe size on this index is also discussed.On the basis of practical consideration,selection principle for BAARP and BAMNP is described.The simulations of those two methods for a serial joint-type robot are made in MATLAB,and the simulation results are consistent to the analysis.The mathematical model and the proposed new pose-planning method will lay a solid foundation for future researches on the control and design of all-position welding robots.
基金supported by the National Key R&D Program of China(Grant No.2018YFC1504802)the National Natural Science Foundation of China(Grant No.52074042)the Basic Research and Frontier Exploration Project of Chongqing,China in 2018(Grant No.cstc2018jcyj AX0453)。
文摘Predicting rock cracking is important for assessing the stability of underground engineering.The effects of the intersecting angle a and the distribution orientation angleβof intersecting fissures on the uniaxial compressive strength and the failure characteristics of sandstone containing intersecting fissures are investigated through laboratory experiments and two-dimensional particle flow code(PFC2D).The relationship between the mechanical properties of sandstone and the intersecting angle a and the distribution orientation angleβis analysed.Crack initiation forms and the final failure modes are then categorised and determined via empirical methods.In addition,the cracking processes of intersecting fissures with different a andβvalues are discussed.The results show that variations in the peak stress,peak strain,average modulus,and crack initiation stress of sandstone containing intersecting fissures show a“moth”shape in the space of the a-β-mechanical parameters.Two crack initiation forms are identified:inner tip cracking(usually accompanied by one outer tip cracking)and only outer tips cracking.Two failure modes are observed:(1)the main fracture planes are created at the inner tip and one outer tip,and(2)the main fracture planes are formed at the two outer tips.Two main crack evolution processes of sandstone containing intersecting fissures under uniaxial compression are found.Approaches for quickly determining the crack initiation form and the failure mode are proposed.The combination of the determination equations for the crack initiation form and the failure mode can be used to predict the crack evolution.The approach for determining the crack evolution processes is hence proposed with acceptable precision.
文摘We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Then, the smoothly blending of two cylinders whose axes are non-coplanar is realized by taking intersecting line of conical surface as axes.
文摘This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal forming.The developed methodology has three major steps:subdivision of B-spline surfaces,detection of protrusions and depressions,and recognition of geometric features for sheet metal forming domain.The input geometry data format of the part is based on an IGES CAD surface model represented in the form of trimmed B-spline surfaces.Each surface is classified or subdivided into different curvature regions with the aid of curvature property surfaces obtained by using symbolic computation of B-spline surfaces.Those regions satisfying a particular geometry and topology relation are recognized as protrusion and depression(DP) shapes.The DP shapes are then classified into different geometric features using a rule-based approach.A verified feasibility study of the developed method is also presented.
基金Project supported by the National Natural Science Foundation of China(Grant No.61233001)the Fundamental Research Funds for the Central Universities,China(Grant No.2017JBM014)
文摘This paper focuses on the simulation analysis of stripe formation and dynamic features of intersecting pedestrian flows.The intersecting flows consist of two streams of pedestrians and each pedestrian stream has a desired walking direction.The model adopted in the simulations is the social force model, which can reproduce the self-organization phenomena successfully. Three scenarios of different cross angles are established. The simulations confirm the empirical observations that there is a stripe formation when two streams of pedestrians intersect and the direction of the stripes is perpendicular to the sum of the directional vectors of the two streams. It can be concluded from the numerical simulation results that smaller cross angle results in higher mean speed and lower level of speed fluctuation. Moreover, the detailed pictures of pedestrians＇ moving behavior at intersections are given as well.
基金supported by the National Key Research and Development Program of China Grant No. 2020YFC2201504by the Projects No. 11875062, No. 11947302, and No. 12047 503 supported by the National Natural Science Foundation of China+1 种基金by the Key Research Program of the Chinese Academy of Sciences, Grant NO. XDPB15supported by KIAS Individual Grant PG080701。
文摘We investigate the construction of four-family N= 1 supersymmetric Pati-Salam models from Type IIA T^(6)×Z_(2) Z_(2) orientifold with intersecting D6-branes. Utilizing the deterministic algorithm introduced in He W, Li T and Sun R(2021 ar Xiv: hep-th/2112.09632), we obtain 274 types of models with three rectangular tori and distinct gauge coupling relations at string scale,while 6 types of models with two rectangular tori and one tilted torus. In both cases, there exists a class of models with gauge coupling unification at string scale. In particular, for the models with two rectangular tori, one tilted torus and gauge coupling unification, the gaugino condensations are allowed, and thus supersymmetry breaking and moduli stabilization are possible for further phenomenological study.
基金Suppored by Postdoctral Fellowship Foundation of China
文摘Let Cnk denote the set of all t -subsets of an n -set. Assume A ∈ Cnk and B∈Cn.b (A,B) is called a cross-2-intersecting family if |A∩B|≥2 for any A∈A, B∈B.In this paper, the best upper bounds of the cardinalities for non-empty cross-2-intersecting families of a- and i- subsets are obtained for some n and b . A new proof for a Frankl-Tokushige theorem [6] is also given.
基金financially supported by the National Natural Science Foundation of China(Grant 52175099)the China Postdoctoral Science Foundation(Grant No.2020M671494)+1 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds(Grant No.2020Z179)the Nanjing University of Science and Technology Independent Research Program(Grant No.30920021105)。
文摘To improve the hit probability of tank at high speed,a prediction method of projectile-target intersection based on adaptive robust constraint-following control and interval uncertainty analysis is proposed.The method proposed provides a novel way to predict the impact point of projectile for moving tank.First,bidirectional stability constraints and stability constraint-following error are constructed using the Udwadia-Kalaba theory,and an adaptive robust constraint-following controller is designed considering uncertainties.Second,the exterior ballistic ordinary differential equation with uncertainties is integrated into the controller,and the pointing control of stability system is extended to the impact-point control of projectile.Third,based on the interval uncertainty analysis method combining Chebyshev polynomial expansion and affine arithmetic,a prediction method of projectile-target intersection is proposed.Finally,the co-simulation experiment is performed by establishing the multi-body system dynamic model of tank and mathematical model of control system.The results demonstrate that the prediction method of projectile-target intersection based on uncertainty analysis can effectively decrease the uncertainties of system,improve the prediction accuracy,and increase the hit probability.The adaptive robust constraint-following control can effectively restrain the uncertainties caused by road excitation and model error.
基金the National Science and Technology Major Project(No.2019700160157)the Natural Science Foundation of Hunan Province(No.2021JJ40761)+3 种基金the Central South University Innovation-Driven Research Programmme(No.v2023CXQD030)the Independent Innovation Fund Project Aero Engine Corporation of China(No.CXPT-2021-001)the Postgraduate Scientific Research Innovation Project of Hunan Province(No.CX20230163)the Fundamental Research Funds for the Cen-tral Universities of Central South University(No.2023ZZTS0078)for providing financial support.
文摘Dynamic recrystallization(DRX)is of great significance for the thermomechanical processing and microstructural regulation of TiAl intermetallics.However,the underlying DRX mechanism remains poorly understood.In this study,an Avrami kinetics model for DRX was established,which was capable of predicting the DRX fraction accurately.In addition,the effect of Al_(2)O_(3)short fiber on the DRX mechanisms of TiAl matrix composite during the isothermal compression was investigated for the first time.The re-sults showed that other than inhibiting DRX by particles in the TiAl matrix composites,the addition of Al_(2)O_(3)short fiber accelerated a novel DRX process,which was induced by twinning and twin intersec-tions(TDRX).Thus,this composite exhibited a higher DRX rate than that of the as-cast TiAl monolithic alloy.The origin of the twin intersection and TDRX for the composite was revealed.The stress concentration near the Al_(2)O_(3)fiber was above the critical shear stress for twinning and thus was favorable for the formation of twinning and twin intersections.The high stored strain energy at the regions of twins and twin intersections provided the driving force for TDRX.TDRX accelerated the grain refinement in the TiAl matrix near the Al_(2)O_(3)fiber.The present findings would provide a new perspective on DRX mechanisms,and provide the scientific guidance for optimizing the microstructures of TiAl matrix composites.
基金support from the Key Technology Research and Development Program of Shandong Province(Project No.2019GGX102060).
文摘This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of electron backscattered diffraction investigations showed that the activated twins were primarily{1012}tension twins,and 60°<1010>boundaries formed due to twin–twin intersections under different strain rates.Isolated twin variants with 60°<1010>boundaries transformed into new grains through lattice rotations at a low strain rate(0.01 s^(−1)).At a high strain rate(10 s^(−1)),the regions surrounded by subgrain boundaries through high-density dislocation arrangement and the 60°<1010>boundaries transformed into new grains via dynamic recrystallization.
文摘The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the analytic expression of them. Finally, with computer programming language, it gives a program to generate the intersection in several different cases.
基金the National Natural Science Foundation of China(Nos.11971311,11531001)the Montenegrin-Chinese Science and Technology Cooperation Project(No.3-12).
文摘The celebrated Erdos-Ko-Rado theorem states that given n≥2k,every intersecting k-uni-n-1 form hypergraph G on n vertices has at most(n-1 k-1)edges.This paper states spectral versions of the Erd6s-_Ko--Rado theorem:let G be an intersecting k-uniform hypergraph on n vertices with n≥2k.Then,the sharp upper bounds for the spectral radius of Aα(G)and 2*(G)are presented,where Aα(G)=αD(G)+(1-α).A(G)is a convex linear combination of the degree diagonal tensor D(G)and the adjacency tensor A(G)for 0≤α<1,and Q^(*)(G)is the incidence Q-tensor,respectively.Furthermore,when n>2k,the extremal hypergraphs which attain the sharp upper bounds are characterized.The proof mainly relies on the Perron-Frobenius theorem for nonnegative tensor and the property of the maximizing connected hypergraphs.
基金This work was supported by Natural Science Foundation of Fujian Province(Grant No.2020J01873)Science and Technology Major Project of Fujian Province(Grant No.2020HZ03018).
文摘In order to establish the groove model for intersecting structures of circular tubes,mathematical model of the intersecting line is established by the method of analytic geometry,and parametric equations are thus determined.The dihedral angle,groove angle and actual cutting angle for any position of the intersecting line are derived as well.In order to identify groove vectors for two pipes,a new analytical method,i.e.coplanarity of vectors,is further proposed to complete the groove model.The established model is virtually verified by programming and simulation calculation in the MATLAB environment.The results show that groove vectors of intersecting structures simulated by MATLAB are consistent with the theoretical groove model,indicating that the theoretical groove model established in this paper is accurate,and further proves that the proposed coplanarity of vectors for solving groove vectors is correct and feasible.Finally,a graphical user interface(GUI)is developed by MATLAB software to independently realize functions such as model drawing,variable calculation and data output.The research outcome provides a theoretical foundation for the actual welding of circular intersecting structures,and lays an essential basis for weld bead layout and path planning.
