In recent years,the environment of railways and the systems such as CBTC(communication based train control)have been changing.To respond the changes and the needs of customers,a UTCS(unified train control system)has b...In recent years,the environment of railways and the systems such as CBTC(communication based train control)have been changing.To respond the changes and the needs of customers,a UTCS(unified train control system)has been developed to realize a system that evolves with customers.Previous type systems consist of independent components such as ATC(Automatic train control)system,electronic interlocking system,and facility monitoring system,and there are a complicated overlap of system configurations and functions and difference in concept between the systems.On the other hand,the integrated train control system consists of horizontal layers such as function layer,network layer,and terminal layer.Therefore,the system has been developed to make it simple with no unnecessary redundancy and evolving to meet the needs of customers.In this paper,we explain a method that realizes the interlocking function for CBTC system in the function layer based on the concept of“securing a train travelling path”including path blocking and routing,and evaluate the safety of the method using STAMP/STPA.展开更多
Inspired by brick-and-mortar architectures and suture interfaces,we propose a design of bioinspired nacre-like materials with interlocking sutures to improve the toughness of brittle materials.Laser-engraved glass int...Inspired by brick-and-mortar architectures and suture interfaces,we propose a design of bioinspired nacre-like materials with interlocking sutures to improve the toughness of brittle materials.Laser-engraved glass interlockers are laminated with soft interlayers in a staggered arrangement,and the fundamental mechanical properties of the structure are investigated through experiments and numerical modeling.It is found that the tensile performance,such as the strength and toughness,is strongly affected by the interlocking angle and suture line spacing.The geometric interlocking originated from suture interfaces as well as tablet sliding arising from the staggered arrangement of interlockers cooperatively contribute to enhancing the strength and toughness of this bioinspired design.Additionally,the finite element modeling shows the interfacial failure and plastic deformation,revealing the interplay of the geometric interlocking mechanism and the sliding mechanism.This novel bioinspired design paves a new path for fabrication of structural materials combining high stiffness,high strength,and enhanced toughness.展开更多
Metallic nanowires have served as novel materials for soft electronics due to their outstanding mechanical compliance and electrical properties.However,weak adhesion and low mechanical robustness of nanowire networks ...Metallic nanowires have served as novel materials for soft electronics due to their outstanding mechanical compliance and electrical properties.However,weak adhesion and low mechanical robustness of nanowire networks to substrates significantly undermine their reliability,necessitating the use of an insulating protective layer,which greatly limits their utility.Herein,we present a versatile and generalized laser-based process that simultaneously achieves strong adhesion and mechanical robustness of nanowire networks on diverse substrates without the need for a protective layer.In this method,the laser-induced photothermal energy at the interface between the nanowire network and the substrate facilitates the interpenetration of the nanowire network and the polymer matrix,resulting in mechanical interlocking through percolation.This mechanism is broadly applicable across different metallic nanowires and thermoplastic substrates,significantly enhancing its universality in diverse applications.Thereby,we demonstrated the mechanical robustness of nanowires in reusable wearable physiological sensors on the skin without compromising the performance of the sensor.Furthermore,enhanced robustness and electrical conductivity by the laser-induced interlocking enables a stable functionalization of conducting polymers in a wet environment,broadening its application into various electrochemical devices.展开更多
Railway transportation system is a critical sector where design methods and techniques are defined by international standards in order to reduce possible risks to an acceptable minimum level. CENELEC 50128 strongly re...Railway transportation system is a critical sector where design methods and techniques are defined by international standards in order to reduce possible risks to an acceptable minimum level. CENELEC 50128 strongly recommends the utilization of finite state machines during system modelling stage and formal proof methods during the verifi- cation and testing stages of control algorithms. Due to the high importance of interlocking table at the design state of a sig- nalization system, the modelling and verification of inter- locking tables are examined in this work. For this purpose, abstract state machines are used as a modelling tool. The developed models have been performed in a generalized structure such that the model control can be done automatically for the interlocking systems. In this study, NuSMV is used at the verification state. Also, the consistency of the developed models has been supervised through fault injection. The developed models and software components are applied on a real railway station operated by Metro Istanbul Co.展开更多
The ultra-fine structured Ni?Al?WC layer with interlocking bonding was fabricated on austenitic stainless steel by combination of laser clad and friction stir processing (FSP). Laser was initially applied to Ni?Al ele...The ultra-fine structured Ni?Al?WC layer with interlocking bonding was fabricated on austenitic stainless steel by combination of laser clad and friction stir processing (FSP). Laser was initially applied to Ni?Al elemental powder preplaced on the austenitic stainless steel substrate to produce a coating for further processing. The as-received coating was subjected to FSP treatment, processed by a rotary tool rod made of WC?Co alloy, to obtain sample for inspection. Microstructure, phase constitutions, hardness and wear property were investigated by methods of scanning electronic microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) microanalysis, and X-ray diffraction (XRD), hardness test alongside with dry sliding wear test. The results show that the severe deformation effect exerted on the specimen resulted in an ultra-fine grain layer of about 100μmin thickness and grain size of 1?2μm. Synergy between introduction of WC particles to the deformation layer and deformation strengthening contributes greatly to the increase in hardness and friction resistance. An interlocking bonding between the coating and matrix which significantly improves bonding strength was formed due to the severe deformation effect.展开更多
Brittle rock has the mechanical characteristics of a high ratio of uniaxial compressive strength to tensilestrength, brittle-ductile transition, and so on. The mineral meso-structure of brittle rock shows theinterlock...Brittle rock has the mechanical characteristics of a high ratio of uniaxial compressive strength to tensilestrength, brittle-ductile transition, and so on. The mineral meso-structure of brittle rock shows theinterlocking behavior and there are some microcracks between the mineral grains, so it is difficult toanalyze the mechanical characteristics accurately with a regular constitutive model. The previous numericalmodels have some limitations when applied to brittle rock, that they cannot provide sufficientinternal interlocking and are incapable of considering the microcracks. These limitations are addressedby using the updated flat-joint contact model to join notional polygonal particles with an initial gap andincreasing the particle coordination number by adding flat-joint contacts to more particles that arewithin some non-zero distance of one another via the range coefficient contact identification method. Acomparison of experimental and numerical results confirms that the updated flat-jointed model providesa good match with the mechanical properties of brittle rock. In this paper, we investigate the influence ofmineral meso-structure (micro-cracks, range coefficient, and radius multiplier) on the meso-mechanicalproperties of Jinping dolomitic marble via the updated flat-joint contact model under direct-tension testsand compression tests. It is found that the updated model can reproduce the microstructure effect ofbrittle rock and can better simulate the mechanical characteristics of the brittle rock than conventionalmodels, such as high strength ratio, brittle-ductile transition, initial nonlinearity, and different modulusin compression and tension.展开更多
To understand the specific behaviors of coastal coral sand slope foundations,discrete element method(DEM)was employed to examine the effect of breakable particle corners on the performance of coral sand slope foundati...To understand the specific behaviors of coastal coral sand slope foundations,discrete element method(DEM)was employed to examine the effect of breakable particle corners on the performance of coral sand slope foundations under a strip footing,from macro to micro scales.The results demonstrate that the bearing characteristics of coral sand slope foundations can be successfully modeled by utilizing breakable corner particles in simulations.The dual effects of interlocking and breakage of corners well explained the specific shallower load transmission and narrower shear stress zones in breakable corner particle slopes.Additionally,the study revealed the significant influence of breakable corners on soil behaviors on slopes.Furthermore,progressive corner breakage within slip bands was successfully identified as the underling mechanism in determining the unique bearing characteristics and the distinct failure patterns of breakable corner particle slopes.This study provides a new perspective to clarify the behaviors of slope foundations composed of breakable corner particle materials.展开更多
Supervisory control and protection system of the neutral beam injector （NBI） in the HL-2A tokamak is presented. The system is used for a safe coordination of all the main NBI subsystems. Because the system is based ...Supervisory control and protection system of the neutral beam injector （NBI） in the HL-2A tokamak is presented. The system is used for a safe coordination of all the main NBI subsystems. Because the system is based on computer networks with its transmission medium of optical fiber, its advantages in high operational stability, reliability, security and flexible functional expandability are clearly shown during the NBI commissioning and heating experiment in HL-2A.展开更多
Proton therapy is the most advanced radiotherapy approach in the world,and causes less damage to normal human tissue than traditional radiotherapy.Because the treatment process produces a high-energy proton beam,the p...Proton therapy is the most advanced radiotherapy approach in the world,and causes less damage to normal human tissue than traditional radiotherapy.Because the treatment process produces a high-energy proton beam,the personnel safety interlock system mainly considers measures to protect personnel from radiation hazards during beam preparation and the beam release process.Unlike other safety interlock systems,the personnel safety interlock system designed in this study focuses on the safety and stability of the system itself.The hardware and software of important interlock control loops are designed and developed according to the requirements of Safety Integrity Level 3 specified by IEC61508.A set of redundant ring networks was developed to ensure that damage to a certain network line does not affect the normal operation of the system.A set of friendly operation interfaces and data storage systems were developed to ensure that the operator can monitor the data in real time and trace the data.The personnel safety interlock system mainly includes a beam enabling function,clearance function,and emergency stop function.The system was put into actual use and successfully ensured personnel safety.展开更多
BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whe...BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association(AO/OTA)guidelines for IT femur fractures.AIM To compare the outcomes of IT fractures(AO/OTA 31-A1 and 31-A2)treated by PFN with and without distal interlocking screws.METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures.We divided the patients into two groups,in which one of the groups received distal interlocking screws(group 1)and the other group did not(group 2).The subjects were followed up for a mean period of 14 mo and assessed for radiological union time,fracture site collapse,mechanical stability of implant,and complications associated with the PFN with distal interlocking and without distal interlocking.Then,the results were compared.RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern.However,similar results were observed in both groups with the fracture pattern AO/OTA 31-A1.In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws,there were minimal proximal lockrelated complications and no risk of distal interlock-related complications.The operative time,IITV radiation time and time to radiological union were reduced.These patients also had better rotational alignment of the proximal femur,and the anatomy of the proximal femur was well maintained.It was also noted that in the cases where distal interlocking was performed,there was a gradual decrease in neck shaft angle,which led to varus collapse and failure of bone-implant construct in 21.40%.CONCLUSION In fracture pattern AO/OTA 31-A2,PFN without distal interlocking had better results and less complications than PFN with distal interlocking.展开更多
An outline of the complete design of the cryogenic system, including the detection of quench signals, the processing flow after a quench and the concrete measures of pressure release for EAST is described in this pape...An outline of the complete design of the cryogenic system, including the detection of quench signals, the processing flow after a quench and the concrete measures of pressure release for EAST is described in this paper. The hardware and software configurations on DeltaV DCS are illustrated in detail. The results of quench protection testing in cooling experiments are also analyzed.展开更多
＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the min...＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the mine goal were obtained. Results show that the flow field in the goaf is generally asymmetric; the location of the gas accumulation area changes with ventilation parameters and can be used as an evaluation indicator to study the air leakage extent in the goal. Hence, drainage pipes buried in the goaf to intensively extract gas can be designed in such gas areas, which can give considerations in both improving gas drainage efficiency and reducing air leakage. By comparing the gas extraction effect of model experiments with that of on-site underground practices, the basic laws are commonly consistent according to comparative analysis. Thus the experimental results can be used to guide the application of underground gas prevent!o_n_and.control..展开更多
Structural connections between components are often weak areas in engineering applications.In nature,many biological materials with remarkablemechanical performance possess flexible and creative sutures.In this work,w...Structural connections between components are often weak areas in engineering applications.In nature,many biological materials with remarkablemechanical performance possess flexible and creative sutures.In this work,we propose a novel bioinspired interlocking tab considering both the geometry of the tab head and neck,and demonstrate a new approach to optimize the bio-inspired interlocking structures based on machine learning.Artificial neural networks for different optimization objectives are developed and trained using a database of thousands of interlocking structures generated through finite element analysis.Results show that the proposed method is able to achieve accurate prediction of the mechanical response of any given interlocking tab.The optimized designs with different optimization objectives,such as strength,stiffness,and toughness,are obtained efficiently and precisely.The optimum design predicted by machine learning is approximately 7.98 times stronger and 2.98 times tougher than the best design in the training set,which are validated through additive manufacturing and experimental testing.The machine learning-based optimization approach developed here can aid in the exploration of the intricate mechanism behind biological materials and the discovery of new material designs boasting orders of magnitude increase in computational efficacy over conventional methods.展开更多
Research question/issue:This study examines whether geographic proximity produces a proximity preference as interlocking firms observe each other and learn innovative behaviors through information transmission among i...Research question/issue:This study examines whether geographic proximity produces a proximity preference as interlocking firms observe each other and learn innovative behaviors through information transmission among interlocking directors.Research findings/insights:We study the performance of A-share-listed companies in China from 2007 to 2017 on the basis of resource dependence theory,agglomeration effect theory,and Porter’s competitive theory.When target firms learn about research and development–related innovation behaviors from interlocking firms closer to them,they experience more efficient learning effects and have improved convergent traits.Moreover,this proximity advantage increases the willingness of the target firm to communicate with and learn from interlocking firms closer to them.Highly developed areas and research and development–intensive industries positively affect the learning efficiency of interlocking firms.Theoretical/academic implications:Our conclusion is consistent with resource dependence theory;target firms in highly developed areas are more willing to imitate and study nearby interlocking firms to maintain their peer relations,innovation potential,and competitiveness.Our conclusion is also consistent with competition theory,which states that the exchange of information between target firms in highly research and development–intensive industries and distant interlocking firms increases innovation differentiation,innovation potential,and competitiveness,even when such exchange has a high cost.Practitioner/policy implications:The results support resource dependence theory and peers’effects.The information obtained by interlocking directorates through external social relations guides firm decision-making,and closer distances reveal more obvious effects.展开更多
AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagital...AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagitally. The following points were identified for each ulna: the deepest point of the incisura olecrani(A), the point where perpendicular lines from A and the ideal IMN entry point(D) are intersected(C) and a point at 3.5 mm(2 mm safety distance from articular surface + 1.5 mm radius of PIS) posterior from point A(B). We calculated the angle of screws inserted from point D through to point B in relation to D-C and B-C. In addition, an eccentrically aligned screw was inserted at a standard 20° through the anterior cortex of the ulna in each bone and the articular surface wasobserved macroscopically for any damage.RESULTS: The mean A-C distance was 9.6 mm(mean ± SD, 9.600 ± 0.763 mm), A-B distance was 3.5 mm, C-D distance was 12.500 mm(12.500 ± 1.371 mm) and the mean angle was 25.9°(25.9°± 2.0°). Lack of articular damage was confirmed macroscopically in all bones after the 20.0° eccentrically aligned screws were inserted. Intramedullary nail fixation systems have well known biological and biomechanical advantages for osteosynthesis. However, as well as these well-known advantages, IMN fixation of the ulna has some limitations. Some important limitations are related to the proximal interlocking of the ulna nail. The location of the PIS itself limits the indications for which intramedullary systems can be selected as an implant for the ulna. The new PIS design, where the PIS is aligned 20°eccentrically to the nail body, allows fixing of fractures even at the level of the olecranon without disturbing the joint. It also allows the eccentrically aligned screw to be inserted in any direction except through the proximal radio-ulnar joint. Taking into consideration our results, we now use a 20° eccentrically aligned PIS for all ulnas. In our results, the angle required to insert the PIS was less than 20° for only one bone. However, 0.7° difference corresponds to placement of the screw only 0.2 mm closer to the articular surface. As we assume 2.0 mm to be a safe distance, a placement of the screw 0.2 mm closer to the articular surface may not produce any clinical symptoms.CONCLUSION: The new PIS may give us the opportunity to interlock IMN without articular damage and confirmation by fluoroscopy if the nail is manufactured with a PIS aligned at a 20.0° fixed angle in relation to the IMN.展开更多
Background: Internal splintage of open tibial fractures had gained acceptance as a preferred method of early stabilization of such injuries. Patients and Methods: Fifty-five patients had been operated upon. They were ...Background: Internal splintage of open tibial fractures had gained acceptance as a preferred method of early stabilization of such injuries. Patients and Methods: Fifty-five patients had been operated upon. They were followed from July 2008 to March 2013 (56 months) with an average time of 39 months. The final results had been evaluated through a scheme including 7 parameters: pain, union, malunion, infection, range motions of nearby joints, implant and technical failure and activity and returning to the same work. Results: According to previous parameters, union was achieved in 52 cases (94.5%) at an average time of 20 weeks (16 - 52 weeks) with 5.5% incidence of nonunion. Excellent and good ranges of knee and ankle motions were achieved at final follow-up visit in 49 cases (89.09%). The incidence of complication was acceptable mainly malunion 7.3%, deep infection 12.7%, implant and technical failure 9.1% full activity and returning to the same work achieved in 89.1%. The overall net results of our series are as follows: excellent—19 cases (34.5%), good—27 cases (49.1%), fair—6 cases (10.9%) and poor—3 cases (5.5%). Conclusion: Utilizing unreamed interlocking nail for open tibial fractures is a good method of treatment particularly those of grade (II), and (IIIA).展开更多
The computer interlocking system has a wide application in realizing interlocking control between the switch, the signal, and the track circuit in station. Due to the similarity between the binary tree and the station...The computer interlocking system has a wide application in realizing interlocking control between the switch, the signal, and the track circuit in station. Due to the similarity between the binary tree and the station-type data structure, the actual station route search method and the recursive algorithm are combined inorder to realize the computer interlocking route search. On this basis, through the design of switch class, track circuit class and signal machine class, by using C++ object-oriented the management of station data structure and entity object are realized, and then the crowding alarm, switch operations and so on in computer interlocking software. Taking the implementation of 5# station computer interlocking software as an example and based on are realized C++ the object-oriented computer interlocking software is written to provide a reference for realizing the railway computer interlocking training system function.展开更多
The feature of porous titanium is that new bone trabecular tissue could ingrow intoits pores and produce interlocking attachment.The spherical TC<sub>4</sub> powder and titanium fiberwere seperately implan...The feature of porous titanium is that new bone trabecular tissue could ingrow intoits pores and produce interlocking attachment.The spherical TC<sub>4</sub> powder and titanium fiberwere seperately implanted into the femurs of 24 dogs.The pore size of the samples was0.24mm and their rates of porosity were 40%～50%.After 3 months,the interface shearstrength examined by straight pulling test,was over 4.60±0.36MPa.Scanning electronmicroscopy showed that there were new bone components in the porous layer.Lightmicroscopy also revealed that there were new bone lacunae and their pathways in it.Thedepth of the reforming bone was 3 mm.Interface shear strength of the new bone in the po-rous layer might meet the need of load bearing.Porous materials would prevent the artificialjoint from loosening and thus help to develop a new service clinically.展开更多
A novel metal-enamel interlocking coating was designed and prepared in situ by co-deposition of Ni-enamel composite layer and subsequent air spray of enamel with 10 wt% nanoscale Ni. During the firing process, the ext...A novel metal-enamel interlocking coating was designed and prepared in situ by co-deposition of Ni-enamel composite layer and subsequent air spray of enamel with 10 wt% nanoscale Ni. During the firing process, the external enamel layer was melted and jointed with the enamel particles at the upper part of the Ni-plating layer to form the enamel pegs. Thermal shock tests of pure enamel, enamel with 10 wt% Ni composite and metal-enamel interlocking coatings were conducted at 600 °C in water and static air. The results indicated that the metal-enamel interlocking showed superior thermal shock resistance to both pure enamel and enamel with 10 wt% Ni composite coatings. The enhanced performance was mainly attributed to the advantageous effects of mechanical interlocking of the enamel pegs formed at the enamel/Ni-plating interface. Meanwhile, during thermal shock test, big clusters formed by nanoscale Ni agglomerations were oxidised to be a Ni/NiO core–shell structure while small single nanoscale Ni grains were oxidised completely, which both improved the thermal shock resistance of enamel coating significantly.展开更多
AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the rib...AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the ribs. Median straight and interlocking sternotomies were performed on 10 sterna each, set as groups 1 and 2, respectively. Both sternotomies were performed with an oscillating saw and closed at three points with a No. 5 straight stainless-stee wiring. Fatigue testing was performed in craniocaudal, anterio-posterior(AP) and lateral directions by a computerized materials-testing machine cycling between loads of 0 to 400 N per 5 s(0.2 Hz). The amount of displacement in AP, lateral and craniocaudal directions were measured and also the op-posing bone surface at the osteotomy areas were calculated at the two halves of sternum. RESULTS: The mean displacement in cranio-caudal direction was 9.66 ± 3.34 mm for median sternotomy and was 1.26 ± 0.97 mm for interlocking sternotomy, P < 0.001. The mean displacement in AP direction was 9.12 ± 2.74 mm for median sternotomy and was 1.20 ± 0.55 mm for interlocking sternotomy, P < 0.001. The mean displacement in lateral direction was 8.95 ± 3.86 mm for median sternotomy and was 7.24 ± 2.43 mm for interlocking sternotomy, P > 0.001. The mean surface area was 10.40 ± 0.49 cm2 for median sternotomy and was 16.8 ± 0.78 cm2 for interlocking sternotomy, P < 0.001. The displacement in AP and cranio-caudal directions is less in group 2 and it is statistically significant. Displacement in lateral direction in group 2 is less but it is statistically not significant. Surface area in group 2 is significantly wider than group 1.CONCLUSION: Our test results demonstrated improved primary stability and wider opposing bone surfaces in interlocking sternotomy compared to median sternotomy. This method may provide better healing and less complication rates in clinical setting, further studies are necessary for its clinical implications.展开更多
文摘In recent years,the environment of railways and the systems such as CBTC(communication based train control)have been changing.To respond the changes and the needs of customers,a UTCS(unified train control system)has been developed to realize a system that evolves with customers.Previous type systems consist of independent components such as ATC(Automatic train control)system,electronic interlocking system,and facility monitoring system,and there are a complicated overlap of system configurations and functions and difference in concept between the systems.On the other hand,the integrated train control system consists of horizontal layers such as function layer,network layer,and terminal layer.Therefore,the system has been developed to make it simple with no unnecessary redundancy and evolving to meet the needs of customers.In this paper,we explain a method that realizes the interlocking function for CBTC system in the function layer based on the concept of“securing a train travelling path”including path blocking and routing,and evaluate the safety of the method using STAMP/STPA.
基金Project supported by the National Natural Science Foundation of China(Nos.12202257,12072184,12002197)。
文摘Inspired by brick-and-mortar architectures and suture interfaces,we propose a design of bioinspired nacre-like materials with interlocking sutures to improve the toughness of brittle materials.Laser-engraved glass interlockers are laminated with soft interlayers in a staggered arrangement,and the fundamental mechanical properties of the structure are investigated through experiments and numerical modeling.It is found that the tensile performance,such as the strength and toughness,is strongly affected by the interlocking angle and suture line spacing.The geometric interlocking originated from suture interfaces as well as tablet sliding arising from the staggered arrangement of interlockers cooperatively contribute to enhancing the strength and toughness of this bioinspired design.Additionally,the finite element modeling shows the interfacial failure and plastic deformation,revealing the interplay of the geometric interlocking mechanism and the sliding mechanism.This novel bioinspired design paves a new path for fabrication of structural materials combining high stiffness,high strength,and enhanced toughness.
基金supported by the National Research Foundation of Korea(NRF)Grant(RS-2024-00343512,RS-2024-00416938).
文摘Metallic nanowires have served as novel materials for soft electronics due to their outstanding mechanical compliance and electrical properties.However,weak adhesion and low mechanical robustness of nanowire networks to substrates significantly undermine their reliability,necessitating the use of an insulating protective layer,which greatly limits their utility.Herein,we present a versatile and generalized laser-based process that simultaneously achieves strong adhesion and mechanical robustness of nanowire networks on diverse substrates without the need for a protective layer.In this method,the laser-induced photothermal energy at the interface between the nanowire network and the substrate facilitates the interpenetration of the nanowire network and the polymer matrix,resulting in mechanical interlocking through percolation.This mechanism is broadly applicable across different metallic nanowires and thermoplastic substrates,significantly enhancing its universality in diverse applications.Thereby,we demonstrated the mechanical robustness of nanowires in reusable wearable physiological sensors on the skin without compromising the performance of the sensor.Furthermore,enhanced robustness and electrical conductivity by the laser-induced interlocking enables a stable functionalization of conducting polymers in a wet environment,broadening its application into various electrochemical devices.
文摘Railway transportation system is a critical sector where design methods and techniques are defined by international standards in order to reduce possible risks to an acceptable minimum level. CENELEC 50128 strongly recommends the utilization of finite state machines during system modelling stage and formal proof methods during the verifi- cation and testing stages of control algorithms. Due to the high importance of interlocking table at the design state of a sig- nalization system, the modelling and verification of inter- locking tables are examined in this work. For this purpose, abstract state machines are used as a modelling tool. The developed models have been performed in a generalized structure such that the model control can be done automatically for the interlocking systems. In this study, NuSMV is used at the verification state. Also, the consistency of the developed models has been supervised through fault injection. The developed models and software components are applied on a real railway station operated by Metro Istanbul Co.
基金Projects(51571214,51301205,51101126)supported by the National Natural Science Foundation of ChinaProject(P2014-07)supported by the Open Fund of State Key Laboratory of Materials Processing and Die&Mould Technology,China+4 种基金Project(20130162120001)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(K1308034-11)supported by the Changsha Municipal Science and Technology Plan,ChinaProjects(2015GK3004,2015JC3006)supported by the Science and Technology Project of Hunan Province,ChinaProject supported by the Innovation-driven Plan in Central South University,ChinaProject supported by the Independent Project of State Key Laboratory of Powder Metallurgy of Central South University,China
文摘The ultra-fine structured Ni?Al?WC layer with interlocking bonding was fabricated on austenitic stainless steel by combination of laser clad and friction stir processing (FSP). Laser was initially applied to Ni?Al elemental powder preplaced on the austenitic stainless steel substrate to produce a coating for further processing. The as-received coating was subjected to FSP treatment, processed by a rotary tool rod made of WC?Co alloy, to obtain sample for inspection. Microstructure, phase constitutions, hardness and wear property were investigated by methods of scanning electronic microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) microanalysis, and X-ray diffraction (XRD), hardness test alongside with dry sliding wear test. The results show that the severe deformation effect exerted on the specimen resulted in an ultra-fine grain layer of about 100μmin thickness and grain size of 1?2μm. Synergy between introduction of WC particles to the deformation layer and deformation strengthening contributes greatly to the increase in hardness and friction resistance. An interlocking bonding between the coating and matrix which significantly improves bonding strength was formed due to the severe deformation effect.
基金funding support from the National Natural Science Foundation of China(NSFC,Grant No.51428902)the China Scholarship Council(CSC,Grant No.202306270120).
文摘Brittle rock has the mechanical characteristics of a high ratio of uniaxial compressive strength to tensilestrength, brittle-ductile transition, and so on. The mineral meso-structure of brittle rock shows theinterlocking behavior and there are some microcracks between the mineral grains, so it is difficult toanalyze the mechanical characteristics accurately with a regular constitutive model. The previous numericalmodels have some limitations when applied to brittle rock, that they cannot provide sufficientinternal interlocking and are incapable of considering the microcracks. These limitations are addressedby using the updated flat-joint contact model to join notional polygonal particles with an initial gap andincreasing the particle coordination number by adding flat-joint contacts to more particles that arewithin some non-zero distance of one another via the range coefficient contact identification method. Acomparison of experimental and numerical results confirms that the updated flat-jointed model providesa good match with the mechanical properties of brittle rock. In this paper, we investigate the influence ofmineral meso-structure (micro-cracks, range coefficient, and radius multiplier) on the meso-mechanicalproperties of Jinping dolomitic marble via the updated flat-joint contact model under direct-tension testsand compression tests. It is found that the updated model can reproduce the microstructure effect ofbrittle rock and can better simulate the mechanical characteristics of the brittle rock than conventionalmodels, such as high strength ratio, brittle-ductile transition, initial nonlinearity, and different modulusin compression and tension.
基金Projects(51878103,52208370)supported by the National Natural Science Foundation of ChinaProject(cstc2020jcyjcxtt X0003)supported by the Innovation Group Science Foundation of the Natural Science Foundation of Chongqing,ChinaProject(2022CDJQY-012)supported by the Fundamental Research Funds for the Central Universities,China。
文摘To understand the specific behaviors of coastal coral sand slope foundations,discrete element method(DEM)was employed to examine the effect of breakable particle corners on the performance of coral sand slope foundations under a strip footing,from macro to micro scales.The results demonstrate that the bearing characteristics of coral sand slope foundations can be successfully modeled by utilizing breakable corner particles in simulations.The dual effects of interlocking and breakage of corners well explained the specific shallower load transmission and narrower shear stress zones in breakable corner particle slopes.Additionally,the study revealed the significant influence of breakable corners on soil behaviors on slopes.Furthermore,progressive corner breakage within slip bands was successfully identified as the underling mechanism in determining the unique bearing characteristics and the distinct failure patterns of breakable corner particle slopes.This study provides a new perspective to clarify the behaviors of slope foundations composed of breakable corner particle materials.
文摘Supervisory control and protection system of the neutral beam injector （NBI） in the HL-2A tokamak is presented. The system is used for a safe coordination of all the main NBI subsystems. Because the system is based on computer networks with its transmission medium of optical fiber, its advantages in high operational stability, reliability, security and flexible functional expandability are clearly shown during the NBI commissioning and heating experiment in HL-2A.
文摘Proton therapy is the most advanced radiotherapy approach in the world,and causes less damage to normal human tissue than traditional radiotherapy.Because the treatment process produces a high-energy proton beam,the personnel safety interlock system mainly considers measures to protect personnel from radiation hazards during beam preparation and the beam release process.Unlike other safety interlock systems,the personnel safety interlock system designed in this study focuses on the safety and stability of the system itself.The hardware and software of important interlock control loops are designed and developed according to the requirements of Safety Integrity Level 3 specified by IEC61508.A set of redundant ring networks was developed to ensure that damage to a certain network line does not affect the normal operation of the system.A set of friendly operation interfaces and data storage systems were developed to ensure that the operator can monitor the data in real time and trace the data.The personnel safety interlock system mainly includes a beam enabling function,clearance function,and emergency stop function.The system was put into actual use and successfully ensured personnel safety.
文摘BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association(AO/OTA)guidelines for IT femur fractures.AIM To compare the outcomes of IT fractures(AO/OTA 31-A1 and 31-A2)treated by PFN with and without distal interlocking screws.METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures.We divided the patients into two groups,in which one of the groups received distal interlocking screws(group 1)and the other group did not(group 2).The subjects were followed up for a mean period of 14 mo and assessed for radiological union time,fracture site collapse,mechanical stability of implant,and complications associated with the PFN with distal interlocking and without distal interlocking.Then,the results were compared.RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern.However,similar results were observed in both groups with the fracture pattern AO/OTA 31-A1.In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws,there were minimal proximal lockrelated complications and no risk of distal interlock-related complications.The operative time,IITV radiation time and time to radiological union were reduced.These patients also had better rotational alignment of the proximal femur,and the anatomy of the proximal femur was well maintained.It was also noted that in the cases where distal interlocking was performed,there was a gradual decrease in neck shaft angle,which led to varus collapse and failure of bone-implant construct in 21.40%.CONCLUSION In fracture pattern AO/OTA 31-A2,PFN without distal interlocking had better results and less complications than PFN with distal interlocking.
基金supported by National Meg-Science Engineering Project of Chinese Government (No.10575105)
文摘An outline of the complete design of the cryogenic system, including the detection of quench signals, the processing flow after a quench and the concrete measures of pressure release for EAST is described in this paper. The hardware and software configurations on DeltaV DCS are illustrated in detail. The results of quench protection testing in cooling experiments are also analyzed.
基金supported by the National Natural Science Foundation of China (Nos. 51174198 and 51304203)Supported by State Key Laboratory of Coal Resources and Safe Mining (No. SKLCRSM11X01)
文摘＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the mine goal were obtained. Results show that the flow field in the goaf is generally asymmetric; the location of the gas accumulation area changes with ventilation parameters and can be used as an evaluation indicator to study the air leakage extent in the goal. Hence, drainage pipes buried in the goaf to intensively extract gas can be designed in such gas areas, which can give considerations in both improving gas drainage efficiency and reducing air leakage. By comparing the gas extraction effect of model experiments with that of on-site underground practices, the basic laws are commonly consistent according to comparative analysis. Thus the experimental results can be used to guide the application of underground gas prevent!o_n_and.control..
基金supported by the National Natural Science Foundation of China,Grant No.51875440.
文摘Structural connections between components are often weak areas in engineering applications.In nature,many biological materials with remarkablemechanical performance possess flexible and creative sutures.In this work,we propose a novel bioinspired interlocking tab considering both the geometry of the tab head and neck,and demonstrate a new approach to optimize the bio-inspired interlocking structures based on machine learning.Artificial neural networks for different optimization objectives are developed and trained using a database of thousands of interlocking structures generated through finite element analysis.Results show that the proposed method is able to achieve accurate prediction of the mechanical response of any given interlocking tab.The optimized designs with different optimization objectives,such as strength,stiffness,and toughness,are obtained efficiently and precisely.The optimum design predicted by machine learning is approximately 7.98 times stronger and 2.98 times tougher than the best design in the training set,which are validated through additive manufacturing and experimental testing.The machine learning-based optimization approach developed here can aid in the exploration of the intricate mechanism behind biological materials and the discovery of new material designs boasting orders of magnitude increase in computational efficacy over conventional methods.
基金funded by the NSFC number(71903199)NSSFC number(19ZDA061,19AJY027)Financial support from the Innovation and Talent Base for Digital Technology and Finance(B21038).
文摘Research question/issue:This study examines whether geographic proximity produces a proximity preference as interlocking firms observe each other and learn innovative behaviors through information transmission among interlocking directors.Research findings/insights:We study the performance of A-share-listed companies in China from 2007 to 2017 on the basis of resource dependence theory,agglomeration effect theory,and Porter’s competitive theory.When target firms learn about research and development–related innovation behaviors from interlocking firms closer to them,they experience more efficient learning effects and have improved convergent traits.Moreover,this proximity advantage increases the willingness of the target firm to communicate with and learn from interlocking firms closer to them.Highly developed areas and research and development–intensive industries positively affect the learning efficiency of interlocking firms.Theoretical/academic implications:Our conclusion is consistent with resource dependence theory;target firms in highly developed areas are more willing to imitate and study nearby interlocking firms to maintain their peer relations,innovation potential,and competitiveness.Our conclusion is also consistent with competition theory,which states that the exchange of information between target firms in highly research and development–intensive industries and distant interlocking firms increases innovation differentiation,innovation potential,and competitiveness,even when such exchange has a high cost.Practitioner/policy implications:The results support resource dependence theory and peers’effects.The information obtained by interlocking directorates through external social relations guides firm decision-making,and closer distances reveal more obvious effects.
文摘AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagitally. The following points were identified for each ulna: the deepest point of the incisura olecrani(A), the point where perpendicular lines from A and the ideal IMN entry point(D) are intersected(C) and a point at 3.5 mm(2 mm safety distance from articular surface + 1.5 mm radius of PIS) posterior from point A(B). We calculated the angle of screws inserted from point D through to point B in relation to D-C and B-C. In addition, an eccentrically aligned screw was inserted at a standard 20° through the anterior cortex of the ulna in each bone and the articular surface wasobserved macroscopically for any damage.RESULTS: The mean A-C distance was 9.6 mm(mean ± SD, 9.600 ± 0.763 mm), A-B distance was 3.5 mm, C-D distance was 12.500 mm(12.500 ± 1.371 mm) and the mean angle was 25.9°(25.9°± 2.0°). Lack of articular damage was confirmed macroscopically in all bones after the 20.0° eccentrically aligned screws were inserted. Intramedullary nail fixation systems have well known biological and biomechanical advantages for osteosynthesis. However, as well as these well-known advantages, IMN fixation of the ulna has some limitations. Some important limitations are related to the proximal interlocking of the ulna nail. The location of the PIS itself limits the indications for which intramedullary systems can be selected as an implant for the ulna. The new PIS design, where the PIS is aligned 20°eccentrically to the nail body, allows fixing of fractures even at the level of the olecranon without disturbing the joint. It also allows the eccentrically aligned screw to be inserted in any direction except through the proximal radio-ulnar joint. Taking into consideration our results, we now use a 20° eccentrically aligned PIS for all ulnas. In our results, the angle required to insert the PIS was less than 20° for only one bone. However, 0.7° difference corresponds to placement of the screw only 0.2 mm closer to the articular surface. As we assume 2.0 mm to be a safe distance, a placement of the screw 0.2 mm closer to the articular surface may not produce any clinical symptoms.CONCLUSION: The new PIS may give us the opportunity to interlock IMN without articular damage and confirmation by fluoroscopy if the nail is manufactured with a PIS aligned at a 20.0° fixed angle in relation to the IMN.
文摘Background: Internal splintage of open tibial fractures had gained acceptance as a preferred method of early stabilization of such injuries. Patients and Methods: Fifty-five patients had been operated upon. They were followed from July 2008 to March 2013 (56 months) with an average time of 39 months. The final results had been evaluated through a scheme including 7 parameters: pain, union, malunion, infection, range motions of nearby joints, implant and technical failure and activity and returning to the same work. Results: According to previous parameters, union was achieved in 52 cases (94.5%) at an average time of 20 weeks (16 - 52 weeks) with 5.5% incidence of nonunion. Excellent and good ranges of knee and ankle motions were achieved at final follow-up visit in 49 cases (89.09%). The incidence of complication was acceptable mainly malunion 7.3%, deep infection 12.7%, implant and technical failure 9.1% full activity and returning to the same work achieved in 89.1%. The overall net results of our series are as follows: excellent—19 cases (34.5%), good—27 cases (49.1%), fair—6 cases (10.9%) and poor—3 cases (5.5%). Conclusion: Utilizing unreamed interlocking nail for open tibial fractures is a good method of treatment particularly those of grade (II), and (IIIA).
文摘The computer interlocking system has a wide application in realizing interlocking control between the switch, the signal, and the track circuit in station. Due to the similarity between the binary tree and the station-type data structure, the actual station route search method and the recursive algorithm are combined inorder to realize the computer interlocking route search. On this basis, through the design of switch class, track circuit class and signal machine class, by using C++ object-oriented the management of station data structure and entity object are realized, and then the crowding alarm, switch operations and so on in computer interlocking software. Taking the implementation of 5# station computer interlocking software as an example and based on are realized C++ the object-oriented computer interlocking software is written to provide a reference for realizing the railway computer interlocking training system function.
文摘The feature of porous titanium is that new bone trabecular tissue could ingrow intoits pores and produce interlocking attachment.The spherical TC<sub>4</sub> powder and titanium fiberwere seperately implanted into the femurs of 24 dogs.The pore size of the samples was0.24mm and their rates of porosity were 40%～50%.After 3 months,the interface shearstrength examined by straight pulling test,was over 4.60±0.36MPa.Scanning electronmicroscopy showed that there were new bone components in the porous layer.Lightmicroscopy also revealed that there were new bone lacunae and their pathways in it.Thedepth of the reforming bone was 3 mm.Interface shear strength of the new bone in the po-rous layer might meet the need of load bearing.Porous materials would prevent the artificialjoint from loosening and thus help to develop a new service clinically.
基金financially supported by the Excellent Youth Foundation of Liaoning Province(No.2019-YQ-03)the CNPC Science and Technology Development Project(Nos.2019B4013 and 2019A-3911)+2 种基金the National Key R&D Program of China(Nos.2019YFF0217500 and 2016ZX05022-055)the Science Fund for Distinguished Young Scholars of Shaanxi Provincethe Ministry of Industry and Information Technology Project(No.MJ-2017-J-99)。
文摘A novel metal-enamel interlocking coating was designed and prepared in situ by co-deposition of Ni-enamel composite layer and subsequent air spray of enamel with 10 wt% nanoscale Ni. During the firing process, the external enamel layer was melted and jointed with the enamel particles at the upper part of the Ni-plating layer to form the enamel pegs. Thermal shock tests of pure enamel, enamel with 10 wt% Ni composite and metal-enamel interlocking coatings were conducted at 600 °C in water and static air. The results indicated that the metal-enamel interlocking showed superior thermal shock resistance to both pure enamel and enamel with 10 wt% Ni composite coatings. The enhanced performance was mainly attributed to the advantageous effects of mechanical interlocking of the enamel pegs formed at the enamel/Ni-plating interface. Meanwhile, during thermal shock test, big clusters formed by nanoscale Ni agglomerations were oxidised to be a Ni/NiO core–shell structure while small single nanoscale Ni grains were oxidised completely, which both improved the thermal shock resistance of enamel coating significantly.
文摘AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the ribs. Median straight and interlocking sternotomies were performed on 10 sterna each, set as groups 1 and 2, respectively. Both sternotomies were performed with an oscillating saw and closed at three points with a No. 5 straight stainless-stee wiring. Fatigue testing was performed in craniocaudal, anterio-posterior(AP) and lateral directions by a computerized materials-testing machine cycling between loads of 0 to 400 N per 5 s(0.2 Hz). The amount of displacement in AP, lateral and craniocaudal directions were measured and also the op-posing bone surface at the osteotomy areas were calculated at the two halves of sternum. RESULTS: The mean displacement in cranio-caudal direction was 9.66 ± 3.34 mm for median sternotomy and was 1.26 ± 0.97 mm for interlocking sternotomy, P < 0.001. The mean displacement in AP direction was 9.12 ± 2.74 mm for median sternotomy and was 1.20 ± 0.55 mm for interlocking sternotomy, P < 0.001. The mean displacement in lateral direction was 8.95 ± 3.86 mm for median sternotomy and was 7.24 ± 2.43 mm for interlocking sternotomy, P > 0.001. The mean surface area was 10.40 ± 0.49 cm2 for median sternotomy and was 16.8 ± 0.78 cm2 for interlocking sternotomy, P < 0.001. The displacement in AP and cranio-caudal directions is less in group 2 and it is statistically significant. Displacement in lateral direction in group 2 is less but it is statistically not significant. Surface area in group 2 is significantly wider than group 1.CONCLUSION: Our test results demonstrated improved primary stability and wider opposing bone surfaces in interlocking sternotomy compared to median sternotomy. This method may provide better healing and less complication rates in clinical setting, further studies are necessary for its clinical implications.
