Let G be a simple graph with n (≥5) vertices. In this paper, we prove that if G is 3 connected and satisfies that d(u,v) =2 implies max {d(u),d(v)} ≥(n+1) /2 for every pair of vertices u and...Let G be a simple graph with n (≥5) vertices. In this paper, we prove that if G is 3 connected and satisfies that d(u,v) =2 implies max {d(u),d(v)} ≥(n+1) /2 for every pair of vertices u and v in G , then for any two vertices x, y of G , there are (x,y) paths of length from 6 to n -1 in G , and there are (x,y) paths of length from 5 to n -1 in G unless G[(x )] = G[(y )]≌ K 4 or K 5 , or G [(x )], G [(y )] are complete and (x)∩(y)=.展开更多
This paper concerns the existence of multiple homoclinic orbits for the second-order Hamiltonian system-L(t)z+Wz(t,z)=0,where L∈C(R,RN2)is a symmetric matrix-valued function and W(t,z)∈C1(R×RN,R)is a...This paper concerns the existence of multiple homoclinic orbits for the second-order Hamiltonian system-L(t)z+Wz(t,z)=0,where L∈C(R,RN2)is a symmetric matrix-valued function and W(t,z)∈C1(R×RN,R)is a nonlinear term.Since there are no periodic assumptions on L(t)and W(t,z)in t,one should overcome difficulties for the lack of compactness of the Sobolev embedding.Moreover,the nonlinearity W(t,z)is asymptotically linear in z at infinity and the system is allowed to be resonant,which is a case that has never been considered before.By virtue of some generalized mountain pass theorem,multiple homoclinic orbits are obtained.展开更多
Road condition is an important variable to measure in order to decrease road and vehicle operating/maintenance costs, but also to increase ride comfort and traffic safety. By using the built-in vibration sensor in sma...Road condition is an important variable to measure in order to decrease road and vehicle operating/maintenance costs, but also to increase ride comfort and traffic safety. By using the built-in vibration sensor in smart phones, it is possible to collect road roughness data which can be an indicator of road condition up to a level of Class 2 or 3 in a simple and cost efficient way. Since data collection therefore is possible to be done more frequently, one can better monitor roughness changes over time. The continuous data collection can also give early warnings of changes and damage, enable new ways to work in the operational road maintenance management, and can serve as a guide for more accurate surveys for strategic asset management and pavement planning. Collected measurement data are wirelessly transferred by the operator when needed via a web service to an internet mapping server with spatial filtering functions. The measured data can be aggregated in preferred sections, as well as exported to other GlS (geographical information systems) or road management systems. Our conclusion is that measuring roads with smart phones can provide an efficient, scalable, and cost-effective way for road organizations to deliver road condition data.展开更多
This paper firstly introduces the distribution of weathered layers, and then presents the relationship between watercontent and expansive force and the working model of expansive forces in expansive soil slopes. Takin...This paper firstly introduces the distribution of weathered layers, and then presents the relationship between watercontent and expansive force and the working model of expansive forces in expansive soil slopes. Taking the expansive soil slope ofJing-Yi Expressway as example and applying the Slices Method, this paper puts forward the stability calculation method con-sidering the effect of expansive forces, and also proposes the treatments.展开更多
Regarding the postulate of traffic infrastructure and vehicles, much attention should be given to the effect of road conditions on accidents. With large numbers of traffic accidents on Shenda Freeway, Liaoning Provinc...Regarding the postulate of traffic infrastructure and vehicles, much attention should be given to the effect of road conditions on accidents. With large numbers of traffic accidents on Shenda Freeway, Liaoning Province, Harbin City and others in P. R. China, parameters and the effect of accidents caused by horizontal alignment, vertical alignment, cross section and intersection are studied systematically The disciplinary analysis of these effects are presented in this paper. The viewpoint is acknowledged that high sub grade and steep slopes are against traffic safety, which is common and ignored in high-usage highways in China. Design parameters of the current design criteria and the corresponding countermeasures are suggested for safety on our highways.展开更多
Based on the initiative of "One Belt and One Road" and the demand analysis of the international shipping market for high-quality maritime talents with good skills of communicating ability and international vision, t...Based on the initiative of "One Belt and One Road" and the demand analysis of the international shipping market for high-quality maritime talents with good skills of communicating ability and international vision, this paper analyzes the feasibility, necessity, construction goal, construction principle, construction content, tutorial setting, tutorial structure and tutorial demonstration and explore how" to make China maritime universities' have ability to train the international students in an efficient and orderly manner; by investigating the relevant enterprises and institutions, and presents a plan for the construction of "One Hundred Courses, One Thousand Class-Hours".展开更多
Many studies have been conducted by analyzing crash data that included road profile, site conditions, vehicle configurations and weights, driver behavior, etc.. However, limited studies have been conducted evaluating ...Many studies have been conducted by analyzing crash data that included road profile, site conditions, vehicle configurations and weights, driver behavior, etc.. However, limited studies have been conducted evaluating the impact of these factors on crashes and/or rollover through simulations. This is mainly due to lack of availability of verified full vehicle flexible-body models. The verification process is costly as it requires instrumentation of a heavy vehicle, scanning of road surfaces, and collection of data by running the vehicle over different road conditions, performing various maneuvering, etc. This paper presents the reverse engineering process of a class-8 truck and validation of a full flexible-body simulation model of a Wabash 53-foot trailer against the strain data recoded from proving ground testing of an instrumented truck. Simulation results show that, with the exception of the noise from the strain gage data from instrumented test run at 30 mph, there is a good agreement in periodicity and relative amplitude with the ADAMS model. A comparison of strain data from the flex-body model and the instrumented truck shows that the modeling and verification approach presented in this paper can be confidently used to validate the full flexible-body models developed for specific analyses.展开更多
Relative to countries such as Russia, the United States, and Europe, China has only recently occupied a place in the energy sector in Kazakhstan. However, after 10 years of hard work, China has come to the fore and th...Relative to countries such as Russia, the United States, and Europe, China has only recently occupied a place in the energy sector in Kazakhstan. However, after 10 years of hard work, China has come to the fore and the fierce energy competition in Kazakhstan has become an important energy trading partner of Central Asian countries. Therefore, we can learn a lot of experience and lessons from our emphasis on cooperation with China's energy trade and research in Central Asian countries. Against the backdrop of fierce international energy competition and the deep implementation of the "One Belt and One Road" initiative, it is like a double-edged sword for energy trade cooperation between China and Central Asian countries, problem. How China seizes opportunities, resolves challenges, and further deepens pragmatic cooperation in the energy sector with Central Asian countries so as to better protect the country' s energy security is a very real issue.展开更多
A 3D road geometry reconstruction system using on-board camera for vehicle driver assistance is developed. Given calibration of the camera, 3D structure of the road in front of the vehicle is built via multiple vanish...A 3D road geometry reconstruction system using on-board camera for vehicle driver assistance is developed. Given calibration of the camera, 3D structure of the road in front of the vehicle is built via multiple vanishing points estimation and local parallelism of the road. The road will be modeled as a piecewise linear approximation of space curve. Vanishing points are estimated through line grouping and histogram method in the image. The system is not restricted to the roads which lie on 2D plane, but also is capable of recovering a full 3D geometry. The ambiguity of distance (scale) is resolved by usage of parallel line segnents an the road image.展开更多
Modifying the knots of a B-spline curve, the shape of the curve will be changed. In this paper, we present the effect of the symmetric alteration of four knots of the B-spline and the NURBS surfaces, i.e., symmetrical...Modifying the knots of a B-spline curve, the shape of the curve will be changed. In this paper, we present the effect of the symmetric alteration of four knots of the B-spline and the NURBS surfaces, i.e., symmetrical alteration of the knots of surface, the extended paths of points of the surface will converge to a point which should be expressed with several control points. This theory can be used in the constrained shape modification of B-spline and NURBS surfaces.展开更多
Aligned spaces generalize topological spaces and generate Higgs spaces. We give a necessary and sufficient condition for a finite aligned space to be a topological space, we prove the existence of two kinds of convex ...Aligned spaces generalize topological spaces and generate Higgs spaces. We give a necessary and sufficient condition for a finite aligned space to be a topological space, we prove the existence of two kinds of convex geometries, and we compare several concepts and results for arbitrary (that is, not necessarily finite) aligned, topological and Higgs spaces.展开更多
It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety...It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety and effective driving action. In this work,an elaborated 3D model fully compliant with the geometrical size of radial tire 185/60 R15 is worked up, for evaluating the effects of components properties and working conditions on deformation and stress/strain fields created inside the tire. For the simulation, the tire structure is assumed to be composed of tread, carcass ply, and bead. The mechanical behavior of rubber as main component of tire is described by Mooney-Rivlin material model. The comparison of the obtained results and laboratory tests demonstrates the validity and high accuracy of analysis.展开更多
The extraction of potassium from K-feldspar via a calcium chloride calcination route was studied with a focus on the effects of the calcination atmosphere, calcination temperature and time, mass ratio of CaCl2 to K-fe...The extraction of potassium from K-feldspar via a calcium chloride calcination route was studied with a focus on the effects of the calcination atmosphere, calcination temperature and time, mass ratio of CaCl2 to K-feldspar ore and particle size of the K-feldspar ore. The results demonstrated that a competing high-temperature hydrolysis reaction of calcium chloride with moisture in a damp atmosphere occurred concurrently with the conversion reaction of K-feldspar with CaCl2, thus reducing the amount of potassium extracted. The conversion reaction started at approximately 600 °C and accelerated with increasing temperature. When the temperature rose above 900 °C, the extraction of potassium gradually decreased due to the volatilization of the product, KCl.As much as approximately 41% of the potassium was volatilized in 40 min at 1100 °C. The mass ratio of CaCl2/K-feldspar ore significantly affected the extraction. At a mass ratio of 1.15 and 900 °C, the potassium extraction reached 91% in 40 min, while the extraction was reduced to only 22% at the theoretical mass ratio of 0.2. Optimal process conditions are as follows: ore particle size of 50–75 μm, tablet forming pressure of 3 MPa, dry nitrogen atmosphere, mass ratio of CaCl2/ore 1.15:1, calcination temperature of 900 °C, and calcination time of 40 min.The XRD analysis revealed that a complex phase transition of the product SiO2 was also accompanied by the conversion reaction of K-feldspar/CaCl2. The SiO2 product formed at the initial stage was in the quartz phase at 900 °C and was gradually transformed into cristobalite after 30 min.展开更多
The one-pot synthesis of 6-hydroxyhexanoic acid from cyclohexanone via the integrated Baeyer-Villiger oxida-tion and ring opening reaction catalyzed by dealuminated HBEA zeolite has been developed. Under optimized con...The one-pot synthesis of 6-hydroxyhexanoic acid from cyclohexanone via the integrated Baeyer-Villiger oxida-tion and ring opening reaction catalyzed by dealuminated HBEA zeolite has been developed. Under optimized conditions,the cyclohexanone conversion and 6-hydroxyhexanoic acid selectivity are over 95%, respectively. The excellent catalyticperformance is attributed to the activation of carbonyl group of cyclohexanone and the fast hydrolysis and ring opening ofs-caprolactone by both Lewis acid and Br0nsted acid sites under aqueous conditions.展开更多
Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including prog...Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a con- crete experiment while maintaining topological consistency of the road network between the original and the schematic map展开更多
文摘Let G be a simple graph with n (≥5) vertices. In this paper, we prove that if G is 3 connected and satisfies that d(u,v) =2 implies max {d(u),d(v)} ≥(n+1) /2 for every pair of vertices u and v in G , then for any two vertices x, y of G , there are (x,y) paths of length from 6 to n -1 in G , and there are (x,y) paths of length from 5 to n -1 in G unless G[(x )] = G[(y )]≌ K 4 or K 5 , or G [(x )], G [(y )] are complete and (x)∩(y)=.
文摘This paper concerns the existence of multiple homoclinic orbits for the second-order Hamiltonian system-L(t)z+Wz(t,z)=0,where L∈C(R,RN2)is a symmetric matrix-valued function and W(t,z)∈C1(R×RN,R)is a nonlinear term.Since there are no periodic assumptions on L(t)and W(t,z)in t,one should overcome difficulties for the lack of compactness of the Sobolev embedding.Moreover,the nonlinearity W(t,z)is asymptotically linear in z at infinity and the system is allowed to be resonant,which is a case that has never been considered before.By virtue of some generalized mountain pass theorem,multiple homoclinic orbits are obtained.
文摘Road condition is an important variable to measure in order to decrease road and vehicle operating/maintenance costs, but also to increase ride comfort and traffic safety. By using the built-in vibration sensor in smart phones, it is possible to collect road roughness data which can be an indicator of road condition up to a level of Class 2 or 3 in a simple and cost efficient way. Since data collection therefore is possible to be done more frequently, one can better monitor roughness changes over time. The continuous data collection can also give early warnings of changes and damage, enable new ways to work in the operational road maintenance management, and can serve as a guide for more accurate surveys for strategic asset management and pavement planning. Collected measurement data are wirelessly transferred by the operator when needed via a web service to an internet mapping server with spatial filtering functions. The measured data can be aggregated in preferred sections, as well as exported to other GlS (geographical information systems) or road management systems. Our conclusion is that measuring roads with smart phones can provide an efficient, scalable, and cost-effective way for road organizations to deliver road condition data.
文摘This paper firstly introduces the distribution of weathered layers, and then presents the relationship between watercontent and expansive force and the working model of expansive forces in expansive soil slopes. Taking the expansive soil slope ofJing-Yi Expressway as example and applying the Slices Method, this paper puts forward the stability calculation method con-sidering the effect of expansive forces, and also proposes the treatments.
文摘Regarding the postulate of traffic infrastructure and vehicles, much attention should be given to the effect of road conditions on accidents. With large numbers of traffic accidents on Shenda Freeway, Liaoning Province, Harbin City and others in P. R. China, parameters and the effect of accidents caused by horizontal alignment, vertical alignment, cross section and intersection are studied systematically The disciplinary analysis of these effects are presented in this paper. The viewpoint is acknowledged that high sub grade and steep slopes are against traffic safety, which is common and ignored in high-usage highways in China. Design parameters of the current design criteria and the corresponding countermeasures are suggested for safety on our highways.
文摘Based on the initiative of "One Belt and One Road" and the demand analysis of the international shipping market for high-quality maritime talents with good skills of communicating ability and international vision, this paper analyzes the feasibility, necessity, construction goal, construction principle, construction content, tutorial setting, tutorial structure and tutorial demonstration and explore how" to make China maritime universities' have ability to train the international students in an efficient and orderly manner; by investigating the relevant enterprises and institutions, and presents a plan for the construction of "One Hundred Courses, One Thousand Class-Hours".
文摘Many studies have been conducted by analyzing crash data that included road profile, site conditions, vehicle configurations and weights, driver behavior, etc.. However, limited studies have been conducted evaluating the impact of these factors on crashes and/or rollover through simulations. This is mainly due to lack of availability of verified full vehicle flexible-body models. The verification process is costly as it requires instrumentation of a heavy vehicle, scanning of road surfaces, and collection of data by running the vehicle over different road conditions, performing various maneuvering, etc. This paper presents the reverse engineering process of a class-8 truck and validation of a full flexible-body simulation model of a Wabash 53-foot trailer against the strain data recoded from proving ground testing of an instrumented truck. Simulation results show that, with the exception of the noise from the strain gage data from instrumented test run at 30 mph, there is a good agreement in periodicity and relative amplitude with the ADAMS model. A comparison of strain data from the flex-body model and the instrumented truck shows that the modeling and verification approach presented in this paper can be confidently used to validate the full flexible-body models developed for specific analyses.
文摘Relative to countries such as Russia, the United States, and Europe, China has only recently occupied a place in the energy sector in Kazakhstan. However, after 10 years of hard work, China has come to the fore and the fierce energy competition in Kazakhstan has become an important energy trading partner of Central Asian countries. Therefore, we can learn a lot of experience and lessons from our emphasis on cooperation with China's energy trade and research in Central Asian countries. Against the backdrop of fierce international energy competition and the deep implementation of the "One Belt and One Road" initiative, it is like a double-edged sword for energy trade cooperation between China and Central Asian countries, problem. How China seizes opportunities, resolves challenges, and further deepens pragmatic cooperation in the energy sector with Central Asian countries so as to better protect the country' s energy security is a very real issue.
基金supperted by the National ITIndustry Promotion Agency(NIPA)(NIPA-2010-C1090-1021-0010),KOREA
文摘A 3D road geometry reconstruction system using on-board camera for vehicle driver assistance is developed. Given calibration of the camera, 3D structure of the road in front of the vehicle is built via multiple vanishing points estimation and local parallelism of the road. The road will be modeled as a piecewise linear approximation of space curve. Vanishing points are estimated through line grouping and histogram method in the image. The system is not restricted to the roads which lie on 2D plane, but also is capable of recovering a full 3D geometry. The ambiguity of distance (scale) is resolved by usage of parallel line segnents an the road image.
基金Project supported by the National Natural Science Foundation of China (No. 60473130) and the National Basic Research Program (973) of China (No. G2004CB318000)
文摘Modifying the knots of a B-spline curve, the shape of the curve will be changed. In this paper, we present the effect of the symmetric alteration of four knots of the B-spline and the NURBS surfaces, i.e., symmetrical alteration of the knots of surface, the extended paths of points of the surface will converge to a point which should be expressed with several control points. This theory can be used in the constrained shape modification of B-spline and NURBS surfaces.
文摘Aligned spaces generalize topological spaces and generate Higgs spaces. We give a necessary and sufficient condition for a finite aligned space to be a topological space, we prove the existence of two kinds of convex geometries, and we compare several concepts and results for arbitrary (that is, not necessarily finite) aligned, topological and Higgs spaces.
文摘It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety and effective driving action. In this work,an elaborated 3D model fully compliant with the geometrical size of radial tire 185/60 R15 is worked up, for evaluating the effects of components properties and working conditions on deformation and stress/strain fields created inside the tire. For the simulation, the tire structure is assumed to be composed of tread, carcass ply, and bead. The mechanical behavior of rubber as main component of tire is described by Mooney-Rivlin material model. The comparison of the obtained results and laboratory tests demonstrates the validity and high accuracy of analysis.
基金Supported by the Ministry of Science and Technology(State Key Research Plan2013BAC12B03)the National Natural Science Foundation of China(21236004,21336004)
文摘The extraction of potassium from K-feldspar via a calcium chloride calcination route was studied with a focus on the effects of the calcination atmosphere, calcination temperature and time, mass ratio of CaCl2 to K-feldspar ore and particle size of the K-feldspar ore. The results demonstrated that a competing high-temperature hydrolysis reaction of calcium chloride with moisture in a damp atmosphere occurred concurrently with the conversion reaction of K-feldspar with CaCl2, thus reducing the amount of potassium extracted. The conversion reaction started at approximately 600 °C and accelerated with increasing temperature. When the temperature rose above 900 °C, the extraction of potassium gradually decreased due to the volatilization of the product, KCl.As much as approximately 41% of the potassium was volatilized in 40 min at 1100 °C. The mass ratio of CaCl2/K-feldspar ore significantly affected the extraction. At a mass ratio of 1.15 and 900 °C, the potassium extraction reached 91% in 40 min, while the extraction was reduced to only 22% at the theoretical mass ratio of 0.2. Optimal process conditions are as follows: ore particle size of 50–75 μm, tablet forming pressure of 3 MPa, dry nitrogen atmosphere, mass ratio of CaCl2/ore 1.15:1, calcination temperature of 900 °C, and calcination time of 40 min.The XRD analysis revealed that a complex phase transition of the product SiO2 was also accompanied by the conversion reaction of K-feldspar/CaCl2. The SiO2 product formed at the initial stage was in the quartz phase at 900 °C and was gradually transformed into cristobalite after 30 min.
基金supported by the National Basic Research Program of China(973 Program,2006CB202508)the China Petrochemical Corporation Program(SINOPEC Group ST417004)the National Key Research and Development Program of China(2017YFB0306800)
文摘The one-pot synthesis of 6-hydroxyhexanoic acid from cyclohexanone via the integrated Baeyer-Villiger oxida-tion and ring opening reaction catalyzed by dealuminated HBEA zeolite has been developed. Under optimized conditions,the cyclohexanone conversion and 6-hydroxyhexanoic acid selectivity are over 95%, respectively. The excellent catalyticperformance is attributed to the activation of carbonyl group of cyclohexanone and the fast hydrolysis and ring opening ofs-caprolactone by both Lewis acid and Br0nsted acid sites under aqueous conditions.
基金Supported by the National Natural Science Foundation of China(No.40571133).
文摘Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a con- crete experiment while maintaining topological consistency of the road network between the original and the schematic map