The high-performance Basalt Fiber Reinforced Polymer(BFRP)composites have been prepared by guiding Micro/Nano Short Aramid Fiber(MNSAF)into the interlayer to improve the resin-rich region and the interfacial transitio...The high-performance Basalt Fiber Reinforced Polymer(BFRP)composites have been prepared by guiding Micro/Nano Short Aramid Fiber(MNSAF)into the interlayer to improve the resin-rich region and the interfacial transition region,and the flexible fiber bridging claws of MNSAF were constructed to grasp the adjacent layers for stronger interlaminar bond.The lowvelocity impact results show that the MNSAF could improve the impact resistance of BFRP composites.The compression test results demonstrate that the compressive strength and the residual compressive strength after impact of MNSAF-reinforced BFRP composites were greater than those of unreinforced one,exhibiting the greatest 56.2% and 73.3% increments respectively for BFRP composites improved by 4wt%MNSAF.X-ray micro-computed tomography scanning results indicate that the“fiber bridging claws”contributed to better mechanical interlocking to inhibit the crack generation and propagation under impact and compression load,and the original delamination-dominated failure of unreinforced BFRP composites was altered into sheardominated failure of MNSAF-reinforced BFRP composites.Overall,the MNSAF interleaving might be an effective method in manufacturing high-performance laminated fiber in industrial production.展开更多
Let G be a graph, an independent set Y in G is called an essential independent set (or essential set for simplicity), if there is {y 1,y 2} Y such that dist (y 1,y 2)=2. In this paper, we wi...Let G be a graph, an independent set Y in G is called an essential independent set (or essential set for simplicity), if there is {y 1,y 2} Y such that dist (y 1,y 2)=2. In this paper, we will use the technique of the vertex insertion on l connected ( l=k or k+1,k≥2 ) claw free graphs to provide a unified proof for G to be hamiltonian or 1 hamiltonian, the sufficient conditions are expressed by the inequality concerning ∑ki=0N(Y i) and n(Y) for each essential set Y={y 0,y 1,...,y k} of G , where Y i={y i,y i-1 ,...,y i-(b-1) }Y for i∈{0,1,...,k} (the subscriptions of y j ’s will be taken modulo k+1 ), b ( 0【b【k+1 ) is an integer, and n(Y)={v∈V(G): dist (v,Y)≤2 }.展开更多
A graph G is called quasi-claw-free if it satisfies the property： d（x, y） = 2 there exists a vertex u ∈ N（x） ∩ N（y） such that N[u] N[x] ∪ N[y]. In this paper, we show that every 2-connected quasi-claw-free g...A graph G is called quasi-claw-free if it satisfies the property： d（x, y） = 2 there exists a vertex u ∈ N（x） ∩ N（y） such that N[u] N[x] ∪ N[y]. In this paper, we show that every 2-connected quasi-claw-free graph of order n with G F contains a cycle of length at least min{3δ ＋ 2, n}, where F is a family of graphs.展开更多
AIM:To evaluate the outcome of over-the-scope-clip system(OTSC)for endoscopic treatment of various indications in daily clinical practice in Switzerland.METHODS:This prospective,consecutive case series was conducted a...AIM:To evaluate the outcome of over-the-scope-clip system(OTSC)for endoscopic treatment of various indications in daily clinical practice in Switzerland.METHODS:This prospective,consecutive case series was conducted at a tertiary care hospital from September 2010 to January 2014.Indications for OTSC application were fistulae,anastomotic leakage,perforation,unroofed submucosal lesion for biopsy,refractory bleeding,and stent fixation in the gastrointestinal(GI)tract.Primary technical success was defined as the adequate deployment of the OTSC on the target lesion.Clinical success was defined as resolution of the problem;for instance,no requirement for surgery or further endoscopic intervention.In cases of recurrence,retreatment of a lesion with a second intervention was possible.Complications were classified into those related to sedation,endoscopy,or deployment of the clip.RESULTS:A total of 28 OTSC system applications werecarried out in 21 patients[median age 64 years(range42-85),33%females].The main indications were fistulae(52%),mostly after percutaneous endoscopic gastrostomy tube removal,and anastomotic leakage after GI surgery(29%).Further indications were unroofed submucosal lesions after biopsy,upper gastrointestinal bleeding,or esophageal stent fixation.The OTSC treatments were applied either in the upper(48%)or lower(52%)GI tract.The mean lesion size was 8 mm(range:2-20 mm).Primary technical success and clinical success rates were 85%and 67%,respectively.In53%of cases,the suction method was used without accessories(e.g.,twin grasper or tissue anchor).No endoscopy-related or OTSC-related complications were observed.CONCLUSION:OTSC is a useful tool for endoscopic closure of various GI lesions,including fistulae and leakages.Future randomized prospective multicenter trials are warranted.展开更多
The magnetic properties of the claw pole have a direct effect on the output power of a generator Many methods can be used to measure these magnetic properties,each with its own advantages,but an important shortcoming ...The magnetic properties of the claw pole have a direct effect on the output power of a generator Many methods can be used to measure these magnetic properties,each with its own advantages,but an important shortcoming is that all are destructive.In this study,a new non-destructive method to measure the magnetic properties of claw pole was proposed and a corresponding testing set-up was designed.A finite-element model was constructed to simulate the measurement process.Results proved that the measured magnetization-like curves had good agreement with the trend of the input magnetic curves and the effect of the positioning error in the measuring process could be neglected.To further validate the new method,seven types of claw poles of different materials subjected to different heat-treatment processes were forged and tested by both the new method and the conventional ring-sample method.Compared with the latter,the new method showed better consistency,relatively higher accuracy,and much stronger stability of measurement results;however,its sensitivity needs to be improved.The effects of material compositions and heat-treatment parameters on the magnetic properties of the claw pole were briefly analyzed.展开更多
AIM:To compare the efficacy and complications of Artisan iris-claw intraocular lens(IOL)implantation and posterior chamber IOL sulcus fixation for the treatment of aphakic eyes without capsular support after vitrectom...AIM:To compare the efficacy and complications of Artisan iris-claw intraocular lens(IOL)implantation and posterior chamber IOL sulcus fixation for the treatment of aphakic eyes without capsular support after vitrectomy.METHODS:A prospective study of 45 cases was conducted.Forty-five eyes without sufficient lens capsule support following pars plana vitrectomy(PPV)combined lens extraction were divided into two groups.Group A:25 eyes received Artisan iris-claw IOL implantation.Group B:20 eyes received posterior chamber IOL sulcus fixation.The corrected distance visual acuity(CDVA)and intraocular pressure(IOP),corneal endothelial cell loss rate,surgical time and complications were compared between the two groups.Pigment changes of trabecular meshwork and anterior chamber depths were measured at each time point in Artisan group.RESULTS:The mean surgical time of Artisan group was significantly shorter(P【0.05).No statistically significant difference in endothelial cell loss rate was noted between two groups at any time point(P】0.05).CDVA of Artian group was better than that of the sulcus fixation group 1d after surgery(P【0.05)and there was no statistically significant difference 1 and 3mo after surgery(P】0.05).Mean IOP showed no significant differences between groups before and after surgery.The postoperative complications of Artisan group were anterior uveitis,iris depigmentation,pupillary distortion and spontaneous lens dislocation.The complications of sulcus fixation group include choroidal detachment,intraocular haemorrhage,tilt of IOL optic part and retinal detachment.CONCLUSION:Secondary Artisan IOL implantation canbe performed less invasively and in a shorter surgical time period with earlier visual recovery after surgery compared to transscleral suturing fixation of an IOL.This technique is an effective and safe procedure.It is a promising option for the treatment of aphakic eyes without capsular support after vitrectomy.展开更多
Two new sufficient conditions for hamiltonian claw free graphs are given. Some known results become corollaries of the conclusion, the conditions of theorem are the best possible in a sense.
A graph G has the hourglass property if every induced hourglass S（a tree with a degree sequence 22224） contains two non-adjacent vertices which have a common neighbor in G-V（S）.For an integer k≥4,a graph G has th...A graph G has the hourglass property if every induced hourglass S（a tree with a degree sequence 22224） contains two non-adjacent vertices which have a common neighbor in G-V（S）.For an integer k≥4,a graph G has the single k-cycle property if every edge of G,which does not lie in a triangle,lies in a cycle C of order at most k such that C has at least「｜V（C） /2」 edges which do not lie in a triangle,and they are not adjacent.In this paper,we show that every hourglass-free claw-free graph G of δ（G） ≥3 with the single 7-cycle property is Hamiltonian and is best possible;we also show that every claw-free graph G of δ（G） ≥3 with the hourglass property and with single 6-cycle property is Hamiltonian.展开更多
Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for hi...Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for high speed operation. However, because of its complex irregular structure, the manufacturing process using silicon sheets is complicated. Soft magnetic composite material(SMC) is manufactured by powder metallurgy technology, which can produce various shapes of stator core structures, so it is easier to produce various irregular shapes of the stator core. However, the raw SMC material is relatively expensive, and the mechanical strength of SMC is weak. In this paper, a PMCPM with hybrid cores is proposed. With the adoption of hybrid silicon sheet-SMC cores and amorphous alloy-SMC cores, the torque ability of PMCPM can be improved greatly and it can have higher efficiency for more wide operation frequency. Meanwhile, its mechanical strength has been improved and it can be designed for high torque direct drive applications as it is a modular machine. Furthermore, three methods are proposed to reduce the additional eddy current loss which resulted from the employment of hybrid cores in PMCPM.展开更多
We prove the following result: Let G be a 2 connected claw free graph of order n(n≥3) and connectivity k . If for any independent set S k+1 with cardinality k+1 , there exist u,v∈S k+1 ...We prove the following result: Let G be a 2 connected claw free graph of order n(n≥3) and connectivity k . If for any independent set S k+1 with cardinality k+1 , there exist u,v∈S k+1 , such that |N(u)∩N(v)|≥(n-2k)/4 ,then G is Hamiltonian.展开更多
CRABS ClAW （CRC） is a member of the YABBYA transcription factor gene family that plays an important role in floral organ development of plants. This study aimed to further investigate the regulatory function of CRC ...CRABS ClAW （CRC） is a member of the YABBYA transcription factor gene family that plays an important role in floral organ development of plants. This study aimed to further investigate the regulatory function of CRC transcription factor in the development of floral organs of rape （Brassica napus L. ）. A 580 bp fragment of CRC gene was cloned by RT-PCR from total RNA of buds of rape cultivar Ningyou No. 10 to construct an inverted repeated expression cassette of CRC gene using intermediate vector pHturieane. Firstly, CRC gene fragment was positively inserted into the 5＇ end of a spliceable intron and negatively inserted into the 3＇ end of the intron. Subsequently, CaMV35S promoter sequence and inverted repeated expression cassette of CRC gene were transferred into pUC18 multiple clone site of binary expression vector pCAMBIAI1390. The constructed interference expression vector was named pA6-CRCi, which was further confirmed by restriction enzyme digestion and sequencing.展开更多
Let G be a graph,for any u∈V(G),let N(u) denote the neighborhood of u and d(u)=|N(u)| be the degree of u.For any UV(G),let N(U)=∪_~u∈U N(u), and d(U)=|N(U)|.A graph G is called claw-free if it has no induced subgra...Let G be a graph,for any u∈V(G),let N(u) denote the neighborhood of u and d(u)=|N(u)| be the degree of u.For any UV(G),let N(U)=∪_~u∈U N(u), and d(U)=|N(U)|.A graph G is called claw-free if it has no induced subgraph isomorphic to K_~1,3 .One of the fundamental results concerning cycles in claw-free graphs is due to Tian Feng,et al.: Let G be a 2-connected claw-free graph of order n,and d(u)+d(v)+d(w)≥n-2 for every independent vertex set {u,v,w} of G, then G is Hamiltonian. It is proved that,for any three positive integers s,t and w,such that if G is a (s+t+w-1)-connected claw-free graph of order n,and d(S)+d(T)+d(W)>n-(s+t+w) for every three disjoint independent vertex sets S,T,W with |S|=s,|T|=t,|W|=w,and S∪T∪W is also independent,then G is Hamiltonian.Other related results are obtained too.展开更多
Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current ...Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current loss,and simple manufacturing process.The permanent magnet claw pole machine(PMCPM)with SMC cores is a good case that the SMC to be adopted for developing 3D flux electrical machines.In this paper,a novel axial-radial flux permanent magnet claw pole machine(ARPMCPM)with SMC cores and ferrite magnets is proposed.Compared with the traditional PMCPM,the proposed ARPMCPM is designed with only one spoke PM rotor and its whole structure is quite compact.For the performance prediction,the 3D finite element method(FEM)is used.Meanwhile,for the performance evaluation,a previously developed axial flux claw pole permanent magnet machine(AFCPM)is employed as the benchmark machine and all these machines are optimized by using the combined multilevel robust Taguchi method.It can be seen that the proposed ARPMCPM is with higher torque/weight density and operation efficiency.展开更多
The induced matching cover number of a graph G without isolated vertices, denoted by imc(G),is the minimum integer k such that G has k induced matchings {M1,M2,···,Mk}such that,V(M1)∪V(M2)∪··...The induced matching cover number of a graph G without isolated vertices, denoted by imc(G),is the minimum integer k such that G has k induced matchings {M1,M2,···,Mk}such that,V(M1)∪V(M2)∪···∪V(Mk)covers V(G).This paper shows that,if G is a 3-regular claw-free graph,then imc(G)∈{2,3}.展开更多
基金supported financially by the National Natural Science Foundation of China(No.52102115)the High-end Foreign Expert Recruitment Plan of China(No.G2023036002L)+1 种基金the Basalt Fiber and Composite Key Laboratory of Sichuan Province,China(No.XXKFJJ202308)Shock and Vibration of Engineering Materials and Structures Key Lab of Sichuan Province,China(No.23kfgk06).
文摘The high-performance Basalt Fiber Reinforced Polymer(BFRP)composites have been prepared by guiding Micro/Nano Short Aramid Fiber(MNSAF)into the interlayer to improve the resin-rich region and the interfacial transition region,and the flexible fiber bridging claws of MNSAF were constructed to grasp the adjacent layers for stronger interlaminar bond.The lowvelocity impact results show that the MNSAF could improve the impact resistance of BFRP composites.The compression test results demonstrate that the compressive strength and the residual compressive strength after impact of MNSAF-reinforced BFRP composites were greater than those of unreinforced one,exhibiting the greatest 56.2% and 73.3% increments respectively for BFRP composites improved by 4wt%MNSAF.X-ray micro-computed tomography scanning results indicate that the“fiber bridging claws”contributed to better mechanical interlocking to inhibit the crack generation and propagation under impact and compression load,and the original delamination-dominated failure of unreinforced BFRP composites was altered into sheardominated failure of MNSAF-reinforced BFRP composites.Overall,the MNSAF interleaving might be an effective method in manufacturing high-performance laminated fiber in industrial production.
文摘Let G be a graph, an independent set Y in G is called an essential independent set (or essential set for simplicity), if there is {y 1,y 2} Y such that dist (y 1,y 2)=2. In this paper, we will use the technique of the vertex insertion on l connected ( l=k or k+1,k≥2 ) claw free graphs to provide a unified proof for G to be hamiltonian or 1 hamiltonian, the sufficient conditions are expressed by the inequality concerning ∑ki=0N(Y i) and n(Y) for each essential set Y={y 0,y 1,...,y k} of G , where Y i={y i,y i-1 ,...,y i-(b-1) }Y for i∈{0,1,...,k} (the subscriptions of y j ’s will be taken modulo k+1 ), b ( 0【b【k+1 ) is an integer, and n(Y)={v∈V(G): dist (v,Y)≤2 }.
基金Supported by the National Natural Science Foundation of China(Grant No.60673046)
文摘A graph G is called quasi-claw-free if it satisfies the property： d（x, y） = 2 there exists a vertex u ∈ N（x） ∩ N（y） such that N[u] N[x] ∪ N[y]. In this paper, we show that every 2-connected quasi-claw-free graph of order n with G F contains a cycle of length at least min{3δ ＋ 2, n}, where F is a family of graphs.
文摘AIM:To evaluate the outcome of over-the-scope-clip system(OTSC)for endoscopic treatment of various indications in daily clinical practice in Switzerland.METHODS:This prospective,consecutive case series was conducted at a tertiary care hospital from September 2010 to January 2014.Indications for OTSC application were fistulae,anastomotic leakage,perforation,unroofed submucosal lesion for biopsy,refractory bleeding,and stent fixation in the gastrointestinal(GI)tract.Primary technical success was defined as the adequate deployment of the OTSC on the target lesion.Clinical success was defined as resolution of the problem;for instance,no requirement for surgery or further endoscopic intervention.In cases of recurrence,retreatment of a lesion with a second intervention was possible.Complications were classified into those related to sedation,endoscopy,or deployment of the clip.RESULTS:A total of 28 OTSC system applications werecarried out in 21 patients[median age 64 years(range42-85),33%females].The main indications were fistulae(52%),mostly after percutaneous endoscopic gastrostomy tube removal,and anastomotic leakage after GI surgery(29%).Further indications were unroofed submucosal lesions after biopsy,upper gastrointestinal bleeding,or esophageal stent fixation.The OTSC treatments were applied either in the upper(48%)or lower(52%)GI tract.The mean lesion size was 8 mm(range:2-20 mm).Primary technical success and clinical success rates were 85%and 67%,respectively.In53%of cases,the suction method was used without accessories(e.g.,twin grasper or tissue anchor).No endoscopy-related or OTSC-related complications were observed.CONCLUSION:OTSC is a useful tool for endoscopic closure of various GI lesions,including fistulae and leakages.Future randomized prospective multicenter trials are warranted.
基金Partially supported by National Natural Science Foundation of China(Grant No.51875348)
文摘The magnetic properties of the claw pole have a direct effect on the output power of a generator Many methods can be used to measure these magnetic properties,each with its own advantages,but an important shortcoming is that all are destructive.In this study,a new non-destructive method to measure the magnetic properties of claw pole was proposed and a corresponding testing set-up was designed.A finite-element model was constructed to simulate the measurement process.Results proved that the measured magnetization-like curves had good agreement with the trend of the input magnetic curves and the effect of the positioning error in the measuring process could be neglected.To further validate the new method,seven types of claw poles of different materials subjected to different heat-treatment processes were forged and tested by both the new method and the conventional ring-sample method.Compared with the latter,the new method showed better consistency,relatively higher accuracy,and much stronger stability of measurement results;however,its sensitivity needs to be improved.The effects of material compositions and heat-treatment parameters on the magnetic properties of the claw pole were briefly analyzed.
文摘AIM:To compare the efficacy and complications of Artisan iris-claw intraocular lens(IOL)implantation and posterior chamber IOL sulcus fixation for the treatment of aphakic eyes without capsular support after vitrectomy.METHODS:A prospective study of 45 cases was conducted.Forty-five eyes without sufficient lens capsule support following pars plana vitrectomy(PPV)combined lens extraction were divided into two groups.Group A:25 eyes received Artisan iris-claw IOL implantation.Group B:20 eyes received posterior chamber IOL sulcus fixation.The corrected distance visual acuity(CDVA)and intraocular pressure(IOP),corneal endothelial cell loss rate,surgical time and complications were compared between the two groups.Pigment changes of trabecular meshwork and anterior chamber depths were measured at each time point in Artisan group.RESULTS:The mean surgical time of Artisan group was significantly shorter(P【0.05).No statistically significant difference in endothelial cell loss rate was noted between two groups at any time point(P】0.05).CDVA of Artian group was better than that of the sulcus fixation group 1d after surgery(P【0.05)and there was no statistically significant difference 1 and 3mo after surgery(P】0.05).Mean IOP showed no significant differences between groups before and after surgery.The postoperative complications of Artisan group were anterior uveitis,iris depigmentation,pupillary distortion and spontaneous lens dislocation.The complications of sulcus fixation group include choroidal detachment,intraocular haemorrhage,tilt of IOL optic part and retinal detachment.CONCLUSION:Secondary Artisan IOL implantation canbe performed less invasively and in a shorter surgical time period with earlier visual recovery after surgery compared to transscleral suturing fixation of an IOL.This technique is an effective and safe procedure.It is a promising option for the treatment of aphakic eyes without capsular support after vitrectomy.
文摘Two new sufficient conditions for hamiltonian claw free graphs are given. Some known results become corollaries of the conclusion, the conditions of theorem are the best possible in a sense.
基金Supported by the National Natural Science Foundation of China(11071016 and 11171129)the Beijing Natural Science Foundation(1102015)
文摘A graph G has the hourglass property if every induced hourglass S（a tree with a degree sequence 22224） contains two non-adjacent vertices which have a common neighbor in G-V（S）.For an integer k≥4,a graph G has the single k-cycle property if every edge of G,which does not lie in a triangle,lies in a cycle C of order at most k such that C has at least「｜V（C） /2」 edges which do not lie in a triangle,and they are not adjacent.In this paper,we show that every hourglass-free claw-free graph G of δ（G） ≥3 with the single 7-cycle property is Hamiltonian and is best possible;we also show that every claw-free graph G of δ（G） ≥3 with the hourglass property and with single 6-cycle property is Hamiltonian.
基金supported by the National Natural Science Foundation of China under project 52007047the Outstanding Youth Innovation Project funded by State Key Laboratory of Reliability and Intelligence of Electrical Equipment EERI_OY2021005。
文摘Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for high speed operation. However, because of its complex irregular structure, the manufacturing process using silicon sheets is complicated. Soft magnetic composite material(SMC) is manufactured by powder metallurgy technology, which can produce various shapes of stator core structures, so it is easier to produce various irregular shapes of the stator core. However, the raw SMC material is relatively expensive, and the mechanical strength of SMC is weak. In this paper, a PMCPM with hybrid cores is proposed. With the adoption of hybrid silicon sheet-SMC cores and amorphous alloy-SMC cores, the torque ability of PMCPM can be improved greatly and it can have higher efficiency for more wide operation frequency. Meanwhile, its mechanical strength has been improved and it can be designed for high torque direct drive applications as it is a modular machine. Furthermore, three methods are proposed to reduce the additional eddy current loss which resulted from the employment of hybrid cores in PMCPM.
文摘We prove the following result: Let G be a 2 connected claw free graph of order n(n≥3) and connectivity k . If for any independent set S k+1 with cardinality k+1 , there exist u,v∈S k+1 , such that |N(u)∩N(v)|≥(n-2k)/4 ,then G is Hamiltonian.
基金Supported by National Natural Science Foundation of China(31571710)National 948 Program of China(2011-G23)
文摘CRABS ClAW （CRC） is a member of the YABBYA transcription factor gene family that plays an important role in floral organ development of plants. This study aimed to further investigate the regulatory function of CRC transcription factor in the development of floral organs of rape （Brassica napus L. ）. A 580 bp fragment of CRC gene was cloned by RT-PCR from total RNA of buds of rape cultivar Ningyou No. 10 to construct an inverted repeated expression cassette of CRC gene using intermediate vector pHturieane. Firstly, CRC gene fragment was positively inserted into the 5＇ end of a spliceable intron and negatively inserted into the 3＇ end of the intron. Subsequently, CaMV35S promoter sequence and inverted repeated expression cassette of CRC gene were transferred into pUC18 multiple clone site of binary expression vector pCAMBIAI1390. The constructed interference expression vector was named pA6-CRCi, which was further confirmed by restriction enzyme digestion and sequencing.
文摘Let G be a graph,for any u∈V(G),let N(u) denote the neighborhood of u and d(u)=|N(u)| be the degree of u.For any UV(G),let N(U)=∪_~u∈U N(u), and d(U)=|N(U)|.A graph G is called claw-free if it has no induced subgraph isomorphic to K_~1,3 .One of the fundamental results concerning cycles in claw-free graphs is due to Tian Feng,et al.: Let G be a 2-connected claw-free graph of order n,and d(u)+d(v)+d(w)≥n-2 for every independent vertex set {u,v,w} of G, then G is Hamiltonian. It is proved that,for any three positive integers s,t and w,such that if G is a (s+t+w-1)-connected claw-free graph of order n,and d(S)+d(T)+d(W)>n-(s+t+w) for every three disjoint independent vertex sets S,T,W with |S|=s,|T|=t,|W|=w,and S∪T∪W is also independent,then G is Hamiltonian.Other related results are obtained too.
基金supported by the National Natural Science Foundation of China under project 52007047in part by the Outstanding Youth Innovation Project funded by State Key Laboratory of Reliability and Intelligence of Electrical Equipment EERI_OY2021005,and EERI_KF2021014。
文摘Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current loss,and simple manufacturing process.The permanent magnet claw pole machine(PMCPM)with SMC cores is a good case that the SMC to be adopted for developing 3D flux electrical machines.In this paper,a novel axial-radial flux permanent magnet claw pole machine(ARPMCPM)with SMC cores and ferrite magnets is proposed.Compared with the traditional PMCPM,the proposed ARPMCPM is designed with only one spoke PM rotor and its whole structure is quite compact.For the performance prediction,the 3D finite element method(FEM)is used.Meanwhile,for the performance evaluation,a previously developed axial flux claw pole permanent magnet machine(AFCPM)is employed as the benchmark machine and all these machines are optimized by using the combined multilevel robust Taguchi method.It can be seen that the proposed ARPMCPM is with higher torque/weight density and operation efficiency.
基金Supported by the National Natural Science Foundation of China（10771179）
文摘The induced matching cover number of a graph G without isolated vertices, denoted by imc(G),is the minimum integer k such that G has k induced matchings {M1,M2,···,Mk}such that,V(M1)∪V(M2)∪···∪V(Mk)covers V(G).This paper shows that,if G is a 3-regular claw-free graph,then imc(G)∈{2,3}.
