Shanghai Electric Porcelain Works (SEPW), a subsidiary enterprise of the SEC (Group), is specialized in manufacturing highvoltage surge arresters and fuses as main products, as well as some high-voltage insulators, wa...Shanghai Electric Porcelain Works (SEPW), a subsidiary enterprise of the SEC (Group), is specialized in manufacturing highvoltage surge arresters and fuses as main products, as well as some high-voltage insulators, wall bushings and disconnecting switches for power transmission & distribution systems. In fact, SEPW is展开更多
Recently, the structural fuse has become an important issue in the field of earthquake engineering. Due to the trilinearity of the pushover curve of buildings with metallic structural fuses, the mechanism of the struc...Recently, the structural fuse has become an important issue in the field of earthquake engineering. Due to the trilinearity of the pushover curve of buildings with metallic structural fuses, the mechanism of the structural fuse is investigated through the ductility equation of a single-degree-of-freedom system, and the corresponding damage-reduction spectrum is proposed to design and retrofit buildings. Furthermore, the controlling parameters, the stiffness ratio between the main frame and structural fuse and the ductility factor of the main frame, are parametrically studied, and it is shown that the structural fuse concept can be achieved by specific combinations of the controlling parameters based on the proposed damage-reduction spectrum. Finally, a design example and a retrofit example, variations of real engineering projects after the 2008 Wenchuan earthquake, are provided to demonstrate the effectiveness of the proposed design procedures using buckling restrained braces as the structural fuses.展开更多
Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy require...Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy requires bridges to maintain functionality even after severe earthquakes.In this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic resilience.The CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and piles.Following the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its column.The analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual displacement.In contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar fuses.The damaged fuses can be rapidly replaced to recover bridge seismic resistance following an earthquake.Therefore,the CRPF system helps to achieve the desired postearthquake performance objectives.展开更多
A new remedy is proposed in this study to increase the ductility of cross-braced frames to a level comparable with ductile moment frames.The suggested system consists of one or two concentric steel rings installed in ...A new remedy is proposed in this study to increase the ductility of cross-braced frames to a level comparable with ductile moment frames.The suggested system consists of one or two concentric steel rings installed in the cross-braced bay vertically.The steel rings are designed such that they fail in bending sooner than failure of the braces in compression.Then the rings act as seismic fuses with multiple bending plastic hinges.Using nonlinear static analysis,it is shown that the proposed system can be designed to behave like cross-braced frames with regard to stiffness and strength,and like special moment frames with regard to ductility.Seismic design factors for the proposed system are recommended based on nonlinear pushover and cyclic analysis studies.展开更多
In order to study the detonation velocity deficits of bending flexible detonating fuses,a physical model and a theoretical mathematical equation of detonation velocity deficits for bending flexible detonation fuses we...In order to study the detonation velocity deficits of bending flexible detonating fuses,a physical model and a theoretical mathematical equation of detonation velocity deficits for bending flexible detonation fuses were established based on the detonation wave's corner effects and delay time phenomenon by using non-dimensional analysis method.Besides,a semi-empirical formula of detonation velocity deficit for bending fuses in the same charge size was obtained through experiment and curve fitting.The result shows that an exponential relationship between the detonation velocity deficits and reciprocal of curvature radius.展开更多
Since powder and cotton wool may cause mechanical test fail,and the accuracy of ray detection method is not very ideal,this paper introduces the tiny capacitance detection method for broken gunpowder,in which the medi...Since powder and cotton wool may cause mechanical test fail,and the accuracy of ray detection method is not very ideal,this paper introduces the tiny capacitance detection method for broken gunpowder,in which the medium type capacitive sensor’s capacitance changes when the gunpowder core diameter changes.The detection is based on the relationship between non-electric quantity and electric quantity.Simulation results show that the designed system works well with easy installation and low power consumption.Therefore,it is suitable for broken gunpowder detection.展开更多
Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically...Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically evaluate the seismic behavior of flexural and shear fuse beams situated in short-,medium-and high-rise RC buildings that have HCSWs.Three building groups hypothetically located in a high seismic hazard zone were studied.A series of 2D nonlinear time history analyses was accomplished in OpenSees,using the ground motion records scaled at the design basis earthquake level.It was found that the effectiveness of fuses in HCSWs depends on various factors such as size and scale of the building,allowable rotation value,inter-story drift ratio,residual drift quantity,energy dissipation value of the fuses,etc.The results show that shear fuses better meet the requirements of rotations and drifts.In contrast,flexural fuses dissipate more energy,but their sectional stiffness should increase to meet other requirements.It was concluded that adoption of proper fuses depends on the overall scale of the building and on how associated factors are considered.展开更多
A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage sites.The proposed model extracts the resi...A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage sites.The proposed model extracts the residual strain from the differences in thermoelastic contraction of fused silica with different fictive temperatures from the initial frozen-in temperatures to ambient temperature.The residual stress fields of mitigated damage sites for the CO_(2)laser-annealed case are obtained by a finite element analysis of equilibrium equations and constitutive equations.The simulated results indicate that the proposed model can accurately evaluate the residual stress fields of laser-annealed mitigated damage sites with a complex thermal history.The calculated maximum hoop stress is in good agreement with the reported experimental result.The estimated optical retardance profiles from the calculated radial and hoop stress fields are consistent with the photoelastic measurements.These results provide sufficient evidence to demonstrate the suitability of the proposed model for describing the residual stresses of mitigated fused silica damage sites after CO_(2)laser annealing.展开更多
Near-infrared(NIR)responsive compounds with narrow bandgaps play a crucial role in enhancing the photovoltaic efficiency of organic solar cells(OSCs)by effectively capturing high-energy NIR photons,as well as improvin...Near-infrared(NIR)responsive compounds with narrow bandgaps play a crucial role in enhancing the photovoltaic efficiency of organic solar cells(OSCs)by effectively capturing high-energy NIR photons,as well as improving the NIR sensitivity of organic photodetectors(OPDs)through NIR light detection[1,2].The design principle based on electron-donating and accepting(D−A)structures has led to the development of numerous A−D−A or A−DA’D−A type NIR responsive molecules,such as ITIC and Y6.展开更多
From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open chains.Although the category of aromatic energetic compounds exh...From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open chains.Although the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark materials.The methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich poly-heterocycles.Furthermore,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic materials.In this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.展开更多
The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction ...The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.展开更多
In the last decade,3D printing,especially fused deposition modeling(FDM),has revolutionized manufacturing with intricate designs.Traditional 3-axis FDM printers face challenges with complex geometries,but 5-axis versi...In the last decade,3D printing,especially fused deposition modeling(FDM),has revolutionized manufacturing with intricate designs.Traditional 3-axis FDM printers face challenges with complex geometries,but 5-axis versions offer more design freedom.However,it requires specialized strategies.This research presents a model for 5-axis FDM printers using Bézier curves with an algorithm to enhance print quality.The result shows significant accuracy improvements,especially for curve-based tasks.In addition,this study deepens the understanding of 5-axis FDM technology,setting a solid basis for further research and potentially refining manufacturing methods.展开更多
Introduction: Coccydynia, television disease, and coccygodynia are the different names given to this disabling disease, which can become chronic. It was described by Simson in 1859. Coccydynia means pain at the end of...Introduction: Coccydynia, television disease, and coccygodynia are the different names given to this disabling disease, which can become chronic. It was described by Simson in 1859. Coccydynia means pain at the end of the vertebral column. Non-traumatic coccydynia is a diagnosis, which is never straightforward like traumatic coccydynia because the onset is unclear, and both the patient and the unaware clinician face many challenges in treating it on time and with accuracy. Coccyx was likened to a cuckoo bird’s beak as a curved bone of fused 3 to 5 vertebrae with remnant disc material in some rare cases, unfused segments, linear scoliosis or subluxations and deformities. Stress X-rays of the coccyx in the antero-posterior and lateral views in standing and sitting reveal the “Dynamic Instability” due to congenital coccygeal morphological, pathological and mechanical variations. Material and Methods: This is a complex study having retrograde data collected from online publications from various databases, like PubMed, Embase, and Cochrane Library and also antegrade data collected from 100 patients with their consent from patients in Adam and Eve Specialised Medical Centre-based at Abu Dhabi, UAE and data was processed in the research centre of Krushi Orthopaedic Welfare Society based in India between 2014-2024 following all guidelines of Helsinki and approved by the ethics board of Krushi Orthopaedic Welfare Society. Clinical Presentation: The coccyx is painful, with aches, spasms, and an inability to sit. This affects daily activities without any particular date of onset. The onset remains insidious for the non-traumatic variety of coccydynia. Aetiology and Patho Anatomy: Non-traumatic coccydynia can be caused by a myriad of reasons, like congenital morphological variations, acquired dynamic instabilities, and hidden trauma remaining quiescent to re-surface as a strain-induced pain. Radiological Presentations: Unless clarity is focused on these coccygeal views, the errors of the unevacuated rectum, non-dynamic standing views, improper X-ray exposure and refuge by insurance companies to approve the much needed but multiple views in radiological investigation (Stress X-ray), MRI scan, lack of awareness by the clinician, all lead to missed diagnosis with its repercussions as congenital variations in morphology, acquired changes in structure/mobility, pathologies like tumours like congenital teratoma & adult onset chordoma, Tarlov cysts, pilonidal sinus or infections—even tuberculosis, dural syndrome, stiff coccyx due to ankylosing spondylitis and many others like relation to neurosis have all been documented. Treatment options are outside the scope of this research topic, as only the differential diagnosis is being stressed here, so that the clinician and the patient do not overlook the varying aetiology, which is the first step to timely and appropriate treatment. Conclusion: Level 3 evidence is available pointing towards many aetiologies causing non-traumatic coccydynia, and in this study of 100 patients by Krushi O W S, a non-profit organisation, the results were as follows: 1) Coccydynia is more common in Type II coccyx and bony spicules. 2) Coccydynia is more prevalent when the sacrococcygeal joints are not fused. 3) Coccydynia is more prevalent when there is subluxation at the intercoccygeal joints. 4) Coccydynia is more when the sacral angle is lower. 5) Coccydynia is associated with higher sacrococcygeal curved length. 6) Coccydynia is associated with a lower sacrococcygeal curvature index. 7) Gender variations: The coccygeal curvature index was lower in females with coccydynia;the intercoccygeal angle was lower in males. 8) Both obese and thin individuals can get affected due to different weight-bearing mechanics in play.展开更多
Diseases of the blood system are highly complicated and involve many aspects.This article aimed to put forward the necessity of integrating quality and professional education,the necessity of learning logic,and the im...Diseases of the blood system are highly complicated and involve many aspects.This article aimed to put forward the necessity of integrating quality and professional education,the necessity of learning logic,and the importance of establishing an integrated medical education model when teaching about blood system diseases.According to the requirements of the new medical science,this article puts forward the integration of an“online+offline+clinical”medical education mode based on the social learning theory and a learning evaluation mode based on medical literacy.The fundamental task of cultivating human beings into clinical medical talents with professional ethics,independent learning abilities,interpersonal communication abilities,complex problem-solving abilities,innovative consciousness,and critical thinking was implemented.This article aims to propose an improved construction plan to create a new and improved teaching system in medicine.展开更多
The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-change...The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-changes in the physical force-depth standard curve that seemed to be secured by claims from 1992. The physical and mathematical analyses with closed formulas avoid the still world-wide standardized energy-law violation by not reserving 33.33% (h2 belief) (or 20% h3/2 physical law) of the loading force and thus energy for all not depth producing events but using 100% for the depth formation is a severe violation of the energy law. The not depth producing part of the indentation work cannot be done with zero energy! Both twinning and structural phase-transition onsets and normalized phase-transition energies are now calculated without iterations but with physically correct closed arithmetic equations. These are reported for Berkovich and cubecorner indentations, including their comparison on geometric grounds and an indentation standard without mechanical twinning is proposed. Characteristic data are reported. This is the first detection of the indentation twinning of aluminium at room temperature and the mechanical twinning of fused quartz is also new. Their disqualification as indentation standards is established. Also, the again found higher load phase-transitions disqualify aluminium and fused quartz as ISO-ASTM 14577 (International Standardization Organization and American Society for Testing and Materials) standards for the contact depth “hc” iterations. The incorrect and still world-wide used black-box values for H- and Er-values (the latter are still falsely called “Young’s moduli” even though they are not directional) and all mechanical properties that depend on them. They lack relation to bulk moduli from compression experiments. Experimentally obtained and so published force vs depth parabolas always follow the linear FN = kh3/2 + Fa equation, where Fa is the axis-cut before and after the phase-transition branches (never “h2” as falsely enforced and used for H, Er and giving incorrectly calculated parameters). The regression slopes k are the precise physical hardness values, which for the first time allow for precise calculation of the mechanical qualities by indentation in relation to the geometry of the indenter tip. Exactly 20% of the applied force and thus energy is not available for the indentation depth. Only these scientific k-values must be used for AI-advises at the expense of falsely iterated indentation hardness H-values. Any incorrect H-ISO-ASTM and also the iterated Er-ISO-ASTM modulus values of technical materials in artificial intelligence will be a disaster for the daily safety. The AI must be told that these are unscientific and must therefore be replaced by physical data. Iterated data (3 and 8 free parameters!) cannot be transformed into physical data. One has to start with real experimental loading curves and an absolute ZerodurR standard that must be calibrated with standard force and standard length to create absolute indentation results. .展开更多
In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow sta...In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow state is affected by multiple parameters,with temperature and volumetric flow rate(VFR)being the most critical.The study explores the stable extrusion of flow with a highly sensitive acoustic emission(AE)sensor so that AE signals generated by the friction in the annular region can reflect the flow state more effectively.Nevertheless,the large volume and broad frequency range of the data present processing challenges.This study proposes a method that initially selects short impact signals and then uses the Fast Kurtogram(FK)to identify the frequency with the highest kurtosis for signal filtration.The results indicate that this approach significantly enhances processing speed and improves feature extraction capabilities.By correlating AE characteristics under various parameters with the quality of extruded raster beads,AE can monitor the real-time state of material flow.This study offers a concise and efficient method for monitoring the state of raster beads and demonstrates the potential of online monitoring of the flow states.展开更多
文摘Shanghai Electric Porcelain Works (SEPW), a subsidiary enterprise of the SEC (Group), is specialized in manufacturing highvoltage surge arresters and fuses as main products, as well as some high-voltage insulators, wall bushings and disconnecting switches for power transmission & distribution systems. In fact, SEPW is
基金National Natural Science Foundation of China under Grant Nos.11372061 and 91315301
文摘Recently, the structural fuse has become an important issue in the field of earthquake engineering. Due to the trilinearity of the pushover curve of buildings with metallic structural fuses, the mechanism of the structural fuse is investigated through the ductility equation of a single-degree-of-freedom system, and the corresponding damage-reduction spectrum is proposed to design and retrofit buildings. Furthermore, the controlling parameters, the stiffness ratio between the main frame and structural fuse and the ductility factor of the main frame, are parametrically studied, and it is shown that the structural fuse concept can be achieved by specific combinations of the controlling parameters based on the proposed damage-reduction spectrum. Finally, a design example and a retrofit example, variations of real engineering projects after the 2008 Wenchuan earthquake, are provided to demonstrate the effectiveness of the proposed design procedures using buckling restrained braces as the structural fuses.
基金Supported by:National Natural Science Foundation of China under Grant Nos.52008092,U1934205,51908123the China Postdoctoral Science Foundation under Grant No.2021M690034+1 种基金the International Postdoctoral Exchange Fellowship Program of Chinathe Zhishan Postdoctoral Fellowship Program。
文摘Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy requires bridges to maintain functionality even after severe earthquakes.In this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic resilience.The CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and piles.Following the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its column.The analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual displacement.In contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar fuses.The damaged fuses can be rapidly replaced to recover bridge seismic resistance following an earthquake.Therefore,the CRPF system helps to achieve the desired postearthquake performance objectives.
文摘A new remedy is proposed in this study to increase the ductility of cross-braced frames to a level comparable with ductile moment frames.The suggested system consists of one or two concentric steel rings installed in the cross-braced bay vertically.The steel rings are designed such that they fail in bending sooner than failure of the braces in compression.Then the rings act as seismic fuses with multiple bending plastic hinges.Using nonlinear static analysis,it is shown that the proposed system can be designed to behave like cross-braced frames with regard to stiffness and strength,and like special moment frames with regard to ductility.Seismic design factors for the proposed system are recommended based on nonlinear pushover and cyclic analysis studies.
基金Supported by the Foundation of State Key Laboratory of Explosion Science and Technology(YBKT10-04)
文摘In order to study the detonation velocity deficits of bending flexible detonating fuses,a physical model and a theoretical mathematical equation of detonation velocity deficits for bending flexible detonation fuses were established based on the detonation wave's corner effects and delay time phenomenon by using non-dimensional analysis method.Besides,a semi-empirical formula of detonation velocity deficit for bending fuses in the same charge size was obtained through experiment and curve fitting.The result shows that an exponential relationship between the detonation velocity deficits and reciprocal of curvature radius.
基金National Natural Science Foundation of China(No.6171177)
文摘Since powder and cotton wool may cause mechanical test fail,and the accuracy of ray detection method is not very ideal,this paper introduces the tiny capacitance detection method for broken gunpowder,in which the medium type capacitive sensor’s capacitance changes when the gunpowder core diameter changes.The detection is based on the relationship between non-electric quantity and electric quantity.Simulation results show that the designed system works well with easy installation and low power consumption.Therefore,it is suitable for broken gunpowder detection.
文摘Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically evaluate the seismic behavior of flexural and shear fuse beams situated in short-,medium-and high-rise RC buildings that have HCSWs.Three building groups hypothetically located in a high seismic hazard zone were studied.A series of 2D nonlinear time history analyses was accomplished in OpenSees,using the ground motion records scaled at the design basis earthquake level.It was found that the effectiveness of fuses in HCSWs depends on various factors such as size and scale of the building,allowable rotation value,inter-story drift ratio,residual drift quantity,energy dissipation value of the fuses,etc.The results show that shear fuses better meet the requirements of rotations and drifts.In contrast,flexural fuses dissipate more energy,but their sectional stiffness should increase to meet other requirements.It was concluded that adoption of proper fuses depends on the overall scale of the building and on how associated factors are considered.
基金Project supported by the National Natural Science Foundation of China(Grant No.62275235).
文摘A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage sites.The proposed model extracts the residual strain from the differences in thermoelastic contraction of fused silica with different fictive temperatures from the initial frozen-in temperatures to ambient temperature.The residual stress fields of mitigated damage sites for the CO_(2)laser-annealed case are obtained by a finite element analysis of equilibrium equations and constitutive equations.The simulated results indicate that the proposed model can accurately evaluate the residual stress fields of laser-annealed mitigated damage sites with a complex thermal history.The calculated maximum hoop stress is in good agreement with the reported experimental result.The estimated optical retardance profiles from the calculated radial and hoop stress fields are consistent with the photoelastic measurements.These results provide sufficient evidence to demonstrate the suitability of the proposed model for describing the residual stresses of mitigated fused silica damage sites after CO_(2)laser annealing.
基金supported by the National Natural Science Foundation of China (52263019)the Yunnan Fundamental Research Projects (202301AT070313).
文摘Near-infrared(NIR)responsive compounds with narrow bandgaps play a crucial role in enhancing the photovoltaic efficiency of organic solar cells(OSCs)by effectively capturing high-energy NIR photons,as well as improving the NIR sensitivity of organic photodetectors(OPDs)through NIR light detection[1,2].The design principle based on electron-donating and accepting(D−A)structures has led to the development of numerous A−D−A or A−DA’D−A type NIR responsive molecules,such as ITIC and Y6.
基金National Natural Science Foundation of China(Grant Nos.22075023,22205022,and 22235003)to provide fund for conducting experiments。
文摘From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open chains.Although the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark materials.The methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich poly-heterocycles.Furthermore,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic materials.In this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.
基金the National Natural Science Foundation of China(Grant No.61973033)Preliminary Research of Equipment(Grant No.9090102010305)for funding the experiments。
文摘The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.
基金supported by the Na-tional Natural Science Foundation of China(Nos.51575266,52075258)。
文摘In the last decade,3D printing,especially fused deposition modeling(FDM),has revolutionized manufacturing with intricate designs.Traditional 3-axis FDM printers face challenges with complex geometries,but 5-axis versions offer more design freedom.However,it requires specialized strategies.This research presents a model for 5-axis FDM printers using Bézier curves with an algorithm to enhance print quality.The result shows significant accuracy improvements,especially for curve-based tasks.In addition,this study deepens the understanding of 5-axis FDM technology,setting a solid basis for further research and potentially refining manufacturing methods.
文摘Introduction: Coccydynia, television disease, and coccygodynia are the different names given to this disabling disease, which can become chronic. It was described by Simson in 1859. Coccydynia means pain at the end of the vertebral column. Non-traumatic coccydynia is a diagnosis, which is never straightforward like traumatic coccydynia because the onset is unclear, and both the patient and the unaware clinician face many challenges in treating it on time and with accuracy. Coccyx was likened to a cuckoo bird’s beak as a curved bone of fused 3 to 5 vertebrae with remnant disc material in some rare cases, unfused segments, linear scoliosis or subluxations and deformities. Stress X-rays of the coccyx in the antero-posterior and lateral views in standing and sitting reveal the “Dynamic Instability” due to congenital coccygeal morphological, pathological and mechanical variations. Material and Methods: This is a complex study having retrograde data collected from online publications from various databases, like PubMed, Embase, and Cochrane Library and also antegrade data collected from 100 patients with their consent from patients in Adam and Eve Specialised Medical Centre-based at Abu Dhabi, UAE and data was processed in the research centre of Krushi Orthopaedic Welfare Society based in India between 2014-2024 following all guidelines of Helsinki and approved by the ethics board of Krushi Orthopaedic Welfare Society. Clinical Presentation: The coccyx is painful, with aches, spasms, and an inability to sit. This affects daily activities without any particular date of onset. The onset remains insidious for the non-traumatic variety of coccydynia. Aetiology and Patho Anatomy: Non-traumatic coccydynia can be caused by a myriad of reasons, like congenital morphological variations, acquired dynamic instabilities, and hidden trauma remaining quiescent to re-surface as a strain-induced pain. Radiological Presentations: Unless clarity is focused on these coccygeal views, the errors of the unevacuated rectum, non-dynamic standing views, improper X-ray exposure and refuge by insurance companies to approve the much needed but multiple views in radiological investigation (Stress X-ray), MRI scan, lack of awareness by the clinician, all lead to missed diagnosis with its repercussions as congenital variations in morphology, acquired changes in structure/mobility, pathologies like tumours like congenital teratoma & adult onset chordoma, Tarlov cysts, pilonidal sinus or infections—even tuberculosis, dural syndrome, stiff coccyx due to ankylosing spondylitis and many others like relation to neurosis have all been documented. Treatment options are outside the scope of this research topic, as only the differential diagnosis is being stressed here, so that the clinician and the patient do not overlook the varying aetiology, which is the first step to timely and appropriate treatment. Conclusion: Level 3 evidence is available pointing towards many aetiologies causing non-traumatic coccydynia, and in this study of 100 patients by Krushi O W S, a non-profit organisation, the results were as follows: 1) Coccydynia is more common in Type II coccyx and bony spicules. 2) Coccydynia is more prevalent when the sacrococcygeal joints are not fused. 3) Coccydynia is more prevalent when there is subluxation at the intercoccygeal joints. 4) Coccydynia is more when the sacral angle is lower. 5) Coccydynia is associated with higher sacrococcygeal curved length. 6) Coccydynia is associated with a lower sacrococcygeal curvature index. 7) Gender variations: The coccygeal curvature index was lower in females with coccydynia;the intercoccygeal angle was lower in males. 8) Both obese and thin individuals can get affected due to different weight-bearing mechanics in play.
基金Southwest Medical University 2023 Education and Teaching Reform Research Project(No.27)。
文摘Diseases of the blood system are highly complicated and involve many aspects.This article aimed to put forward the necessity of integrating quality and professional education,the necessity of learning logic,and the importance of establishing an integrated medical education model when teaching about blood system diseases.According to the requirements of the new medical science,this article puts forward the integration of an“online+offline+clinical”medical education mode based on the social learning theory and a learning evaluation mode based on medical literacy.The fundamental task of cultivating human beings into clinical medical talents with professional ethics,independent learning abilities,interpersonal communication abilities,complex problem-solving abilities,innovative consciousness,and critical thinking was implemented.This article aims to propose an improved construction plan to create a new and improved teaching system in medicine.
文摘The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-changes in the physical force-depth standard curve that seemed to be secured by claims from 1992. The physical and mathematical analyses with closed formulas avoid the still world-wide standardized energy-law violation by not reserving 33.33% (h2 belief) (or 20% h3/2 physical law) of the loading force and thus energy for all not depth producing events but using 100% for the depth formation is a severe violation of the energy law. The not depth producing part of the indentation work cannot be done with zero energy! Both twinning and structural phase-transition onsets and normalized phase-transition energies are now calculated without iterations but with physically correct closed arithmetic equations. These are reported for Berkovich and cubecorner indentations, including their comparison on geometric grounds and an indentation standard without mechanical twinning is proposed. Characteristic data are reported. This is the first detection of the indentation twinning of aluminium at room temperature and the mechanical twinning of fused quartz is also new. Their disqualification as indentation standards is established. Also, the again found higher load phase-transitions disqualify aluminium and fused quartz as ISO-ASTM 14577 (International Standardization Organization and American Society for Testing and Materials) standards for the contact depth “hc” iterations. The incorrect and still world-wide used black-box values for H- and Er-values (the latter are still falsely called “Young’s moduli” even though they are not directional) and all mechanical properties that depend on them. They lack relation to bulk moduli from compression experiments. Experimentally obtained and so published force vs depth parabolas always follow the linear FN = kh3/2 + Fa equation, where Fa is the axis-cut before and after the phase-transition branches (never “h2” as falsely enforced and used for H, Er and giving incorrectly calculated parameters). The regression slopes k are the precise physical hardness values, which for the first time allow for precise calculation of the mechanical qualities by indentation in relation to the geometry of the indenter tip. Exactly 20% of the applied force and thus energy is not available for the indentation depth. Only these scientific k-values must be used for AI-advises at the expense of falsely iterated indentation hardness H-values. Any incorrect H-ISO-ASTM and also the iterated Er-ISO-ASTM modulus values of technical materials in artificial intelligence will be a disaster for the daily safety. The AI must be told that these are unscientific and must therefore be replaced by physical data. Iterated data (3 and 8 free parameters!) cannot be transformed into physical data. One has to start with real experimental loading curves and an absolute ZerodurR standard that must be calibrated with standard force and standard length to create absolute indentation results. .
文摘In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow state is affected by multiple parameters,with temperature and volumetric flow rate(VFR)being the most critical.The study explores the stable extrusion of flow with a highly sensitive acoustic emission(AE)sensor so that AE signals generated by the friction in the annular region can reflect the flow state more effectively.Nevertheless,the large volume and broad frequency range of the data present processing challenges.This study proposes a method that initially selects short impact signals and then uses the Fast Kurtogram(FK)to identify the frequency with the highest kurtosis for signal filtration.The results indicate that this approach significantly enhances processing speed and improves feature extraction capabilities.By correlating AE characteristics under various parameters with the quality of extruded raster beads,AE can monitor the real-time state of material flow.This study offers a concise and efficient method for monitoring the state of raster beads and demonstrates the potential of online monitoring of the flow states.