The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the ma...The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the manipulator, and can＇t be applied to dynamic design expediently. Much work has been done in the kinematic optimization, but the work in the dynamic optimization is much less. A global dynamic condition number index is proposed and applied to the dynamic optimization design the parallel manipulator. This paper deals with the dynamic manipulability and dynamic optimization of a two degree-of-freedom （DOF） parallel manipulator. The particular velocity and particular angular velocity matrices of each moving part about the part＇s pivot point are derived fi＇om the kinematic formulation of the manipulator, and the inertial force and inertial movement are obtained utilizing Newton-Euler formulation, then the inverse dynamic model of the parallel manipulator is proposed based on the virtual work principle. The general inertial ellipsoid and dynamic manipulability ellipsoid are applied to evaluate the dynamic performance of the manipulator, a global dynamic condition number index based on the condition number of general inertial matrix in the workspace is proposed, and then the link lengths of the manipulator is redesigned to optimize the dynamic manipulability by this index. The dynamic manipulability of the origin mechanism and the optimized mechanism are compared, the result shows that the optimized one is much better. The global dynamic condition number index has good effect in evaluating the dynamic dexterity of the whole workspace, and is efficient in the dynamic optimal design of the parallel manipulator.展开更多
Vanadium pentoxide(V_(2)O_(5))displays the characteristics of high theoretical specific capacity,high operating voltage,and adjustable layered structure,possessing the considerable potential as cathode in magnesium me...Vanadium pentoxide(V_(2)O_(5))displays the characteristics of high theoretical specific capacity,high operating voltage,and adjustable layered structure,possessing the considerable potential as cathode in magnesium metal batteries(MMBs).Nevertheless,the large charge-radius ratio of Mg^(2+)induces the strong interactions of Mg^(2+)with solvent molecules of electrolyte and anionic framework of cathode,resulting in a notable voltage polarization and structural deterioration during cycling process.Herein,an in-situ multi-scale structural engineering is proposed to activate the interlayer-expanded V_(2)O_(5)cathode(pillared by tetrabutylammonium cation)via adding hexadecyltrimethylammonium bromide(CTAB)additive into electrolyte.During cycling,the in-situ incorporation of CTA^(+)not only enhances the electrostatic shielding effect and Mg species migration,but also stabilizes the interlayer spacing.Besides,CTA^(+)is prone to be adsorbed on cathode surface and induces the loss-free pulverization and amorphization of electroactive grains,leading to the pronounced effect of intercalation pseudocapacitance.CTAB additive also enables to scissor the Mg^(2+)solvation sheath and tailor the insertion mode of Mg species,further endowing V_(2)O_(5)cathode with fast reaction kinetics.Based on these merits,the corresponding V2O5‖Mg full cells exhibit the remarkable rate performance with capacities as high as 317.6,274.4,201.1,and 132.7 mAh g^(-1)at the high current densities of 0.1,0.2,0.5,and 1 A g^(-1),respectively.Moreover,after 1000 cycles,the capacity is still preserved to be 90,4 mAh g^(-1)at 1 A g^(-1)with an average coulombic efficiency of~100%.Our strategy of synergetic modulations of cathode host and electrolyte solvation structures provides new guidance for the development of high-rate,large-capacity,and long-life MMBs.展开更多
Animals exhibit complex responses to external and internal stimuli.The information is computed by interconnected neurons that express numerous ion channels,which modulate the neuronal membrane potential.How can neuron...Animals exhibit complex responses to external and internal stimuli.The information is computed by interconnected neurons that express numerous ion channels,which modulate the neuronal membrane potential.How can neuronal activity orchestrate complex motor patterns or allow learning from previous experience?To answer such questions,we need the ability not only to record,but also to modulate neuronal activity in both space(e.g.,neuronal subsets)and time.展开更多
OBJECTIVE:In recent years,the number of clinical research reports on acupuncture and manipulation for the treatment of greater occipital neuralgia has gradually increased,but the quality is uneven.There is currently n...OBJECTIVE:In recent years,the number of clinical research reports on acupuncture and manipulation for the treatment of greater occipital neuralgia has gradually increased,but the quality is uneven.There is currently no literature evaluating the quality of published reports,which is not conducive to the promotion of clinical use of these therapies.Therefore,this article assessed the reporting quality of randomized controlled trials on acupuncture and manipulation for greater occipital neuralgia.METHODS:Cochrane Library,PubMed,Web of Science,Embase,China National Knowledge Infrastructure(CNKI),VIP,WanFang Data,and Chinese BioMedical Literature Database(CBM)from inception to May 20,2024 were searched.The reporting quality of included randomized controlled trials was independently evaluated by two investigators using the CONSORT statement,STRICTA checklist,and Cochrane bias of risk assessment tool.A third investigator resolved any disagreement.RESULTS:A total of 62 articles were included.Based on the CONSORT statement,59.46%(22/37)of all entries had a reporting rate of less than 50%,mainly including“Identification as a randomized trial in the title(1/62,1.61%),”“How sample size was determined(7/62,11.29%),”“Implementation(1/62,1.61%),”“Blinding(1/62,1.61%),”and“Reports of Funding(4/62,6.45%).”According to the STRICTA checklist,29.41%(5/17)of all entries had a reporting rate of less than 50%,mainly including“Details of other interventions(7/58,12.07%),”“Setting and context of treatment(0/58,0%),”and“Description of participating acupuncturists(0/58,0%).”CONCLUSION:The reporting quality of randomized controlled trials on acupuncture and manipulation therapy for greater occipital neuralgia remains low.Future researchers need to make greater efforts to strictly adhere to the CONSORT statement and STRICTA checklist during trial design,implementation,and reporting.This will facilitate the standardization of research in this field and enhance the reliability and reproducibility of the research results.展开更多
Optical field manipulation,an emerging frontier in photonics,demonstrates significant potential in biomedical microscopy,quantum state engineering,and micro-nano fabrication.To address the critical limitations of curr...Optical field manipulation,an emerging frontier in photonics,demonstrates significant potential in biomedical microscopy,quantum state engineering,and micro-nano fabrication.To address the critical limitations of current optical modulation technologies in achieving full-parameter precision control,we proposed a novel approach for dynamic azimuthal optical field modulation based on dual-spiral arrays.By designing spatially interleaved spiral structures with different initial radii while maintaining identical periodic parameters,we achieved continuous optical modulation spanning the full 0-2πrange in azimuthal field distribution.Through rigorous numerical simulations,we systematically established a quantitative correlation between the structural parameters and azimuthal optical field patterns,revealing,for the first time,a quasi-linear relationship between the radius difference and the resultant optical distribution.This theoretical framework advances our fundamental understanding of structured optical field manipulation as well as provides a new paradigm for programmable photonic device design,with distinct technical advantages in super-resolution imaging and optical tweezer systems.展开更多
Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model a...Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.展开更多
This paper is an attempt to explore the root of the modern paradox across multiple registers in order to uncover a persuasive pattern of contradiction that runs through the very fabric of contemporary existence.We dis...This paper is an attempt to explore the root of the modern paradox across multiple registers in order to uncover a persuasive pattern of contradiction that runs through the very fabric of contemporary existence.We discover that the very logic meant to emancipate the human subject-scientific mastery,bureaucratic order,economic growth,and many others,often recoil upon the subject,generating conditions of fragmentation,depersonalization,and spiritual aridity.Far from rejecting modernity wholesale,our task is a diagnostic one-to enter into the deep fabric of modernity and to decode its operating metaphors and interrogate what holds up the“scaffolding of collective life”.This is in a bid to find the rootedness of genuine human flourishing.Part of the answer,from our analysis,lies in a critical re-thinking within modernity without being subsumed by it.展开更多
Objective:To characterize mosquito larval habitats and the influence of meteorological factors on their prevalence,and to suggest alternatives for vector control in Makkah Al-Mukarramah.Methods:A mosquito survey was c...Objective:To characterize mosquito larval habitats and the influence of meteorological factors on their prevalence,and to suggest alternatives for vector control in Makkah Al-Mukarramah.Methods:A mosquito survey was conducted within the 16 municipalities of Makkah Al-Mukarramah,from November 2022 to October 2023.The characteristics of larval habitats used by all reported species as oviposition sites were determined.Seasonal house,container,and breteau indices were used to determine larval abundance.Results:16 Species belonging to five genera[Aedes(3 spp.),Anopheles(3 spp.),Culex(8 spp.),Culiseta(1 sp.),and Lutzia(1 sp.)]were collected.A total of 185608 potential mosquito larval habitats were surveyed.Of these,95853(67.4%)were Aedes,45522(32%)were Culex,718(0.5%)were Anopheles,and 38(0.03%)were other species;154726(83.4%)were water sources for mosquito larvae,and among these sources,7663(5.0%)were positive for larvae,with 45.9%indoors and 54.1%outdoors.Most of the positive larval habitats were recorded in Al-Shawqiya(1093,14.3%),Al-Sharayia(1003,13.1%)and Al-Umrah(984,12.8%).A total of 142131 mosquito larvae and pupae were collected.The majority number of positive residences for all mosquito larvae was observed in January 2023(1658,21.6%).Conclusions:New appropriate alternatives for vector control are proposed,such as mechanical,biological,and environmental control.展开更多
Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfor...Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfortunately their inverse kinematics have not yet been resolved.This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics,meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships.Therefore,to break through this challenges,the huge coupling relationships are decoupled layer by layer,the kinematic parameters of middle platform are solved by combining Sylvester's elimination method,and the inverse displacements of 2(3RPS)and 2(3SPR)S-PMs are obtained subsequently.This paper not only solves the inverse kinematics of classical 2(3RPS)and 2(3SPR)S-PMs,but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF)6-DOF S-PMs and proposes a corresponding solution.展开更多
[Objectives]To investigate the effects of Visceral Manipulation combined with Enhanced Recovery after Surgery on postoperative recovery in patients undergoing gastrointestinal surgery,and to evaluate its impacts on in...[Objectives]To investigate the effects of Visceral Manipulation combined with Enhanced Recovery after Surgery on postoperative recovery in patients undergoing gastrointestinal surgery,and to evaluate its impacts on inflammatory stress response,gastrointestinal motility recovery,and blood oxygen levels.[Methods]A prospective randomized controlled design was adopted.Eighty patients undergoing gastrointestinal surgery from January 2022 to December 2023 were selected and randomly divided into an observation group(40 cases)and a control group(40 cases).The observation group received Visceral Manipulation therapy in addition to routine Enhanced Recovery after Surgery care,while the control group received only routine Enhanced Recovery after Surgery care.Clinical indicators,inflammatory factors(TNF-α,IL-6,hs-CRP),traumatic stress hormones(cortisol,epinephrine,norepinephrine),gastrointestinal motility indicators(GAS,MTL,GIP),and blood oxygen levels were measured and compared between the two groups on postoperative days 1,5,and 10.[Results]The observation group showed significantly better outcomes in postoperative abdominal distension,time to first flatus and defecation,and hospital stay compared to the control group(P<0.05).Inflammatory factors(TNF-α,IL-6,hs-CRP),traumatic stress hormones(cortisol,epinephrine,norepinephrine),and gastrointestinal motility indicators(GAS,MTL,GIP)were significantly improved in the observation group(P<0.05).Postoperative blood oxygen levels were also significantly higher in the observation group(P<0.05).[Conclusions]Visceral Manipulation combined with Enhanced Recovery after Surgery can significantly improve postoperative recovery in gastrointestinal surgery patients,alleviate inflammatory stress responses,promote gastrointestinal functional recovery,and enhance blood oxygen levels,demonstrating promising clinical application prospects.展开更多
The existing research on rescue robots has focused mainly on reconnaissance,detection,and firefighting,and a small number of robots that can achieve human rescue have problems such as poor safety and stability and ins...The existing research on rescue robots has focused mainly on reconnaissance,detection,and firefighting,and a small number of robots that can achieve human rescue have problems such as poor safety and stability and insufficient carrying capacity.This article addresses the above issues and cleverly combines the advantages of soft robotic arms,underactuated robotic arms,and suction cups based on the principles of bionics.A new design for a robotic arm was proposed,and its working principle was explained.Then,the human rescue process was divided into two stages,and the grasping force of the robotic arm in each stage was analyzed separately.Finally,a prototype of the principle was developed,and the feasibility of the design principle of the robotic arm was verified through grasping experiments on a cross-sectional contour model of the human chest.At the same time,grasping experiments were conducted on different objects to demonstrate the potential application of the robotic arm in grasping ground objects.This research proposes a stress envelope adsorption rescue robot arm inspired by the adhesion ability of the Drosera plant and the stress envelope effect,which can apply force to the entire surface of the human body,reduce local force on the human body,ensure load-bearing capacity and adaptability,and improve the safety and stability of rescue grasping.展开更多
The original intention of the algorithmic recommender system is to grapple with the negative impacts caused by information overload,but the system also can be used as"hypernudge",a new form of online manipul...The original intention of the algorithmic recommender system is to grapple with the negative impacts caused by information overload,but the system also can be used as"hypernudge",a new form of online manipulation,to inten⁃tionally exploit people's cognitive and decision-making gaps to influence their decisions in practice,which is particu⁃larly detrimental to the sustainable development of the digital market.Limiting harmful algorithmic online manipula⁃tion in digital markets has become a challenging task.Globally,both the EU and China have responded to this issue,and the differences between them are so evident that their governance measures can serve as the typical case.The EU focuses on improving citizens'digital literacy and their ability to integrate into digital social life to independently ad⁃dress this issue,and expects to address harmful manipulation behavior through binding and applicable hard law,which is part of the digital strategy.By comparison,although there exist certain legal norms that have made relevant stipula⁃tions on manipulation issues,China continues to issue specific departmental regulations to regulate algorithmic recom⁃mender services,and pays more attention to addressing collective harm caused by algorithmic online manipulation through a multiple co-governance approach led by the government or industry associations to implement supervision.展开更多
Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold...Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold great promise as miniature detectives capable of detecting mi RNAs within cells.However,current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection,particularly within the intricate confines of the cellular microenvironment,due to interference with biological autofluorescence,off-target effects,and a lack of spatiotemporal control.Here,we have designed a dual-stimuli responsive DNA tracker,synergistically utilizing specific intracellular cues and external triggers,which enables spatiotemporal-controlled and precise detection and imaging of miRNAs"on demand".The tracker,which combines zeolitic imidazolate framework-67(ZIF-67)and unique hairpin DNA structures,effectively anchored onto the ZIF-67 through electrostatic interactions,remains in a dormant state until activated by abundant cellular ATP,resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region.Subsequent irradiation triggers specific recognition of the target miRNA.The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal mi RNA detection and exhibits excellent biocompatibility,enabling specific mi RNA recognition"on demand"within cancer cells.This research presents a reliable mi RNA imaging platform in the intricate cellular environment,opening up the possibilities for precise biomedical analysis and disease diagnosis.展开更多
Magnetically responsive microstructured functional surface(MRMFS),capable of dynamically and reversibly switching the surface topography under magnetic actuation,provides a wireless,noninvasive,and instantaneous way t...Magnetically responsive microstructured functional surface(MRMFS),capable of dynamically and reversibly switching the surface topography under magnetic actuation,provides a wireless,noninvasive,and instantaneous way to accurately control the microscale engineered surface.In the last decade,many studies have been conducted to design and optimize MRMFSs for diverse applications,and significant progress has been accomplished.This review comprehensively presents recent advancements and the potential prospects in MRMFSs.We first classify MRMFSs into one-dimensional linear array MRMFSs,two-dimensional planar array MRMFSs,and dynamic self-assembly MRMFSs based on their morphology.Subsequently,an overview of three deformation mechanisms,including magnetically actuated bending deformation,magnetically driven rotational deformation,and magnetically induced self-assembly deformation,are provided.Four main fabrication strategies employed to create MRMFSs are summarized,including replica molding,magnetization-induced self-assembly,laser cutting,and ferrofluid-infused method.Furthermore,the applications of MRMFS in droplet manipulation,solid transport,information encryption,light manipulation,triboelectric nanogenerators,and soft robotics are presented.Finally,the challenges that limit the practical applications of MRMFSs are discussed,and the future development of MRMFSs is proposed.展开更多
The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove vario...The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable, reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation (NCF) and the absolute nodal coordinate formulation (ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility.展开更多
On-demand droplet manipulation plays a critical role in microfluidics,bio/chemical detection and microreactions.Acoustic droplet manipulation has emerged as a promising technique due to its non-contact nature,biocompa...On-demand droplet manipulation plays a critical role in microfluidics,bio/chemical detection and microreactions.Acoustic droplet manipulation has emerged as a promising technique due to its non-contact nature,biocompatibility and precision,circumventing the complexities associated with other methods requiring surface or droplet pretreatment.Despite their promise,existing methods for acoustic droplet manipulation often involve complex hardware setups and difficulty for controlling individual droplet amidst multiple ones.Here we fabricate simple yet effective acoustic tweezers for in-surface and out-of-surface droplet manipulation.It is found that droplets can be transported on the superhydrophobic surfaces when the acoustic radiation force surpasses the friction force.Using a two-axis acoustic tweezer,droplets can be maneuvered along arbitrarily programmed paths on the surfaces.By introducing multiple labyrinthine structures on the superhydrophobic surface,individual droplet manipulation is realized by constraining the unselected droplets in the labyrinthine structures.In addition,a three-axis acoustic tweezer is developed for manipulating droplets in three-dimensional space.Potential applications of the acoustic tweezers for micro-reaction,bio-assay and chemical analysis are also demonstrated.展开更多
The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of ex...The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of existing works remain complex as they usually require the integration of multiscale structures.Here,we introduce phase modulation into the infrared camouflage metasurfaces with metal-dielectric-metal configuration,enabling them to achieve camouflage across more bands.Based on this strategy,a simple but effective single-layer cascaded metasurface is demonstrated for the first time to achieve low reflection at multi-wavelength lasers,low infrared radiation in atmospheric windows,and broadband thermal management.As a proof-of-concept,a 4-inch sample with a minimum linewidth of 1.8μm is fabricated using photolithography.The excellent infrared multispectral camouflage performance is verified in experiments,showing low reflectance in 0.9–1.6μm,low infrared emissivity in mid-wavelength infrared(MWIR)and long-wavelength infrared(LWIR)bands,and high absorptance at the wavelength of 10.6μm.Meanwhile,broadband high emissivity in 5–8μm can provide high-performance radiative heat dissipation.When the input power is 1.57 W·cm^(-2),the surface/radiation temperature of the metasurface decreases by 5.3℃/18.7℃ compared to the reference.The proposed metasurface may trigger further innovation in the design and application of compact multispectral optical devices.展开更多
Controllable liquid manipulation is of paramount scientific and technological importance in various fields,such as the chemical industry,biomedicine,and agricultural production.Magnetic actuation,characterized by rapi...Controllable liquid manipulation is of paramount scientific and technological importance in various fields,such as the chemical industry,biomedicine,and agricultural production.Magnetic actuation,characterized by rapid,contactless,and environmentally benign operation,has emerged as a promising approach for precise liquid control.However,conventional magnetic strategies typically govern droplet movement on open surfaces,facing limitations such as restricted liquid volumes,uncertain flow paths,and inevitable evaporation,thereby constraining their broader practical applications.Recently,a variety of magneticdriven strategies have been developed to dynamically regulate liquids within enclosed spaces,especially through physicochemical mechanisms.These approaches provide efficient control over liquid behavior by leveraging magnetically induced chemical changes,structural deformations,and dragging motions,opening new opportunities for flexible and versatile fluid management.This review explores the design and mechanisms of magneto-responsive confined interfaces for the manipulation of nonmagnetic liquids,highlighting key advancements and potential applications including liquid valves,liquid mixing,liquid flow regulation,and liquid pumping.Finally,the existing challenges and future prospects in this field are presented.展开更多
Microassembly platforms have attracted significant attention recently because of their potential for developing microsystems and devices for a wide range of applications.Despite their considerable poten-tial,existing ...Microassembly platforms have attracted significant attention recently because of their potential for developing microsystems and devices for a wide range of applications.Despite their considerable poten-tial,existing techniques are mainly used in laboratory research settings.This review provides an over-view of the fundamentals,techniques,and applications of microassemblies.Manipulation techniques based on magnetic,optical,acoustic fields,and mechanical systems are discussed,and control systems that rely on machine vision and force feedback are introduced.Additionally,recent applications of microassemblies in microstructure fabrication,microelectromechanical operation,and biomedical engi-neering are examined.This review also highlights unmet technical demands and emerging trends,as well as new research opportunities in this expanding field of research driven by allied technologies such as microrobotics.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 50605041, No. 50775125)National Basic Research Program of China (973 Program, Grant No. 2006CB705400)
文摘The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the manipulator, and can＇t be applied to dynamic design expediently. Much work has been done in the kinematic optimization, but the work in the dynamic optimization is much less. A global dynamic condition number index is proposed and applied to the dynamic optimization design the parallel manipulator. This paper deals with the dynamic manipulability and dynamic optimization of a two degree-of-freedom （DOF） parallel manipulator. The particular velocity and particular angular velocity matrices of each moving part about the part＇s pivot point are derived fi＇om the kinematic formulation of the manipulator, and the inertial force and inertial movement are obtained utilizing Newton-Euler formulation, then the inverse dynamic model of the parallel manipulator is proposed based on the virtual work principle. The general inertial ellipsoid and dynamic manipulability ellipsoid are applied to evaluate the dynamic performance of the manipulator, a global dynamic condition number index based on the condition number of general inertial matrix in the workspace is proposed, and then the link lengths of the manipulator is redesigned to optimize the dynamic manipulability by this index. The dynamic manipulability of the origin mechanism and the optimized mechanism are compared, the result shows that the optimized one is much better. The global dynamic condition number index has good effect in evaluating the dynamic dexterity of the whole workspace, and is efficient in the dynamic optimal design of the parallel manipulator.
基金supported by the National Natural Science Foundation of China(52372249)support by the Program of Shanghai Academic Research Leader(21XD1424400)。
文摘Vanadium pentoxide(V_(2)O_(5))displays the characteristics of high theoretical specific capacity,high operating voltage,and adjustable layered structure,possessing the considerable potential as cathode in magnesium metal batteries(MMBs).Nevertheless,the large charge-radius ratio of Mg^(2+)induces the strong interactions of Mg^(2+)with solvent molecules of electrolyte and anionic framework of cathode,resulting in a notable voltage polarization and structural deterioration during cycling process.Herein,an in-situ multi-scale structural engineering is proposed to activate the interlayer-expanded V_(2)O_(5)cathode(pillared by tetrabutylammonium cation)via adding hexadecyltrimethylammonium bromide(CTAB)additive into electrolyte.During cycling,the in-situ incorporation of CTA^(+)not only enhances the electrostatic shielding effect and Mg species migration,but also stabilizes the interlayer spacing.Besides,CTA^(+)is prone to be adsorbed on cathode surface and induces the loss-free pulverization and amorphization of electroactive grains,leading to the pronounced effect of intercalation pseudocapacitance.CTAB additive also enables to scissor the Mg^(2+)solvation sheath and tailor the insertion mode of Mg species,further endowing V_(2)O_(5)cathode with fast reaction kinetics.Based on these merits,the corresponding V2O5‖Mg full cells exhibit the remarkable rate performance with capacities as high as 317.6,274.4,201.1,and 132.7 mAh g^(-1)at the high current densities of 0.1,0.2,0.5,and 1 A g^(-1),respectively.Moreover,after 1000 cycles,the capacity is still preserved to be 90,4 mAh g^(-1)at 1 A g^(-1)with an average coulombic efficiency of~100%.Our strategy of synergetic modulations of cathode host and electrolyte solvation structures provides new guidance for the development of high-rate,large-capacity,and long-life MMBs.
文摘Animals exhibit complex responses to external and internal stimuli.The information is computed by interconnected neurons that express numerous ion channels,which modulate the neuronal membrane potential.How can neuronal activity orchestrate complex motor patterns or allow learning from previous experience?To answer such questions,we need the ability not only to record,but also to modulate neuronal activity in both space(e.g.,neuronal subsets)and time.
文摘OBJECTIVE:In recent years,the number of clinical research reports on acupuncture and manipulation for the treatment of greater occipital neuralgia has gradually increased,but the quality is uneven.There is currently no literature evaluating the quality of published reports,which is not conducive to the promotion of clinical use of these therapies.Therefore,this article assessed the reporting quality of randomized controlled trials on acupuncture and manipulation for greater occipital neuralgia.METHODS:Cochrane Library,PubMed,Web of Science,Embase,China National Knowledge Infrastructure(CNKI),VIP,WanFang Data,and Chinese BioMedical Literature Database(CBM)from inception to May 20,2024 were searched.The reporting quality of included randomized controlled trials was independently evaluated by two investigators using the CONSORT statement,STRICTA checklist,and Cochrane bias of risk assessment tool.A third investigator resolved any disagreement.RESULTS:A total of 62 articles were included.Based on the CONSORT statement,59.46%(22/37)of all entries had a reporting rate of less than 50%,mainly including“Identification as a randomized trial in the title(1/62,1.61%),”“How sample size was determined(7/62,11.29%),”“Implementation(1/62,1.61%),”“Blinding(1/62,1.61%),”and“Reports of Funding(4/62,6.45%).”According to the STRICTA checklist,29.41%(5/17)of all entries had a reporting rate of less than 50%,mainly including“Details of other interventions(7/58,12.07%),”“Setting and context of treatment(0/58,0%),”and“Description of participating acupuncturists(0/58,0%).”CONCLUSION:The reporting quality of randomized controlled trials on acupuncture and manipulation therapy for greater occipital neuralgia remains low.Future researchers need to make greater efforts to strictly adhere to the CONSORT statement and STRICTA checklist during trial design,implementation,and reporting.This will facilitate the standardization of research in this field and enhance the reliability and reproducibility of the research results.
文摘Optical field manipulation,an emerging frontier in photonics,demonstrates significant potential in biomedical microscopy,quantum state engineering,and micro-nano fabrication.To address the critical limitations of current optical modulation technologies in achieving full-parameter precision control,we proposed a novel approach for dynamic azimuthal optical field modulation based on dual-spiral arrays.By designing spatially interleaved spiral structures with different initial radii while maintaining identical periodic parameters,we achieved continuous optical modulation spanning the full 0-2πrange in azimuthal field distribution.Through rigorous numerical simulations,we systematically established a quantitative correlation between the structural parameters and azimuthal optical field patterns,revealing,for the first time,a quasi-linear relationship between the radius difference and the resultant optical distribution.This theoretical framework advances our fundamental understanding of structured optical field manipulation as well as provides a new paradigm for programmable photonic device design,with distinct technical advantages in super-resolution imaging and optical tweezer systems.
文摘Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.
文摘This paper is an attempt to explore the root of the modern paradox across multiple registers in order to uncover a persuasive pattern of contradiction that runs through the very fabric of contemporary existence.We discover that the very logic meant to emancipate the human subject-scientific mastery,bureaucratic order,economic growth,and many others,often recoil upon the subject,generating conditions of fragmentation,depersonalization,and spiritual aridity.Far from rejecting modernity wholesale,our task is a diagnostic one-to enter into the deep fabric of modernity and to decode its operating metaphors and interrogate what holds up the“scaffolding of collective life”.This is in a bid to find the rootedness of genuine human flourishing.Part of the answer,from our analysis,lies in a critical re-thinking within modernity without being subsumed by it.
文摘Objective:To characterize mosquito larval habitats and the influence of meteorological factors on their prevalence,and to suggest alternatives for vector control in Makkah Al-Mukarramah.Methods:A mosquito survey was conducted within the 16 municipalities of Makkah Al-Mukarramah,from November 2022 to October 2023.The characteristics of larval habitats used by all reported species as oviposition sites were determined.Seasonal house,container,and breteau indices were used to determine larval abundance.Results:16 Species belonging to five genera[Aedes(3 spp.),Anopheles(3 spp.),Culex(8 spp.),Culiseta(1 sp.),and Lutzia(1 sp.)]were collected.A total of 185608 potential mosquito larval habitats were surveyed.Of these,95853(67.4%)were Aedes,45522(32%)were Culex,718(0.5%)were Anopheles,and 38(0.03%)were other species;154726(83.4%)were water sources for mosquito larvae,and among these sources,7663(5.0%)were positive for larvae,with 45.9%indoors and 54.1%outdoors.Most of the positive larval habitats were recorded in Al-Shawqiya(1093,14.3%),Al-Sharayia(1003,13.1%)and Al-Umrah(984,12.8%).A total of 142131 mosquito larvae and pupae were collected.The majority number of positive residences for all mosquito larvae was observed in January 2023(1658,21.6%).Conclusions:New appropriate alternatives for vector control are proposed,such as mechanical,biological,and environmental control.
基金Supported by National Natural Science Foundation of China(Grant No.52275033)National Natural Science Youth Foundation of China(Grant No.52205033)Hebei Provincial Natural Science Foundation of China(Grant No.E2021203019)。
文摘Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfortunately their inverse kinematics have not yet been resolved.This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics,meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships.Therefore,to break through this challenges,the huge coupling relationships are decoupled layer by layer,the kinematic parameters of middle platform are solved by combining Sylvester's elimination method,and the inverse displacements of 2(3RPS)and 2(3SPR)S-PMs are obtained subsequently.This paper not only solves the inverse kinematics of classical 2(3RPS)and 2(3SPR)S-PMs,but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF)6-DOF S-PMs and proposes a corresponding solution.
基金Supported by Guiding Project of Shiyan City,Hubei Province in 2022(22Y30).
文摘[Objectives]To investigate the effects of Visceral Manipulation combined with Enhanced Recovery after Surgery on postoperative recovery in patients undergoing gastrointestinal surgery,and to evaluate its impacts on inflammatory stress response,gastrointestinal motility recovery,and blood oxygen levels.[Methods]A prospective randomized controlled design was adopted.Eighty patients undergoing gastrointestinal surgery from January 2022 to December 2023 were selected and randomly divided into an observation group(40 cases)and a control group(40 cases).The observation group received Visceral Manipulation therapy in addition to routine Enhanced Recovery after Surgery care,while the control group received only routine Enhanced Recovery after Surgery care.Clinical indicators,inflammatory factors(TNF-α,IL-6,hs-CRP),traumatic stress hormones(cortisol,epinephrine,norepinephrine),gastrointestinal motility indicators(GAS,MTL,GIP),and blood oxygen levels were measured and compared between the two groups on postoperative days 1,5,and 10.[Results]The observation group showed significantly better outcomes in postoperative abdominal distension,time to first flatus and defecation,and hospital stay compared to the control group(P<0.05).Inflammatory factors(TNF-α,IL-6,hs-CRP),traumatic stress hormones(cortisol,epinephrine,norepinephrine),and gastrointestinal motility indicators(GAS,MTL,GIP)were significantly improved in the observation group(P<0.05).Postoperative blood oxygen levels were also significantly higher in the observation group(P<0.05).[Conclusions]Visceral Manipulation combined with Enhanced Recovery after Surgery can significantly improve postoperative recovery in gastrointestinal surgery patients,alleviate inflammatory stress responses,promote gastrointestinal functional recovery,and enhance blood oxygen levels,demonstrating promising clinical application prospects.
基金Supported by National Natural Science Foundation of China(Grant No.52475032)Central Government Guides Local Science and Technology Development Fund Projects(Grant No.246Z2001G)Hebei Provincial Natural Science Foundation Key Projects(Grant No.E2021203125).
文摘The existing research on rescue robots has focused mainly on reconnaissance,detection,and firefighting,and a small number of robots that can achieve human rescue have problems such as poor safety and stability and insufficient carrying capacity.This article addresses the above issues and cleverly combines the advantages of soft robotic arms,underactuated robotic arms,and suction cups based on the principles of bionics.A new design for a robotic arm was proposed,and its working principle was explained.Then,the human rescue process was divided into two stages,and the grasping force of the robotic arm in each stage was analyzed separately.Finally,a prototype of the principle was developed,and the feasibility of the design principle of the robotic arm was verified through grasping experiments on a cross-sectional contour model of the human chest.At the same time,grasping experiments were conducted on different objects to demonstrate the potential application of the robotic arm in grasping ground objects.This research proposes a stress envelope adsorption rescue robot arm inspired by the adhesion ability of the Drosera plant and the stress envelope effect,which can apply force to the entire surface of the human body,reduce local force on the human body,ensure load-bearing capacity and adaptability,and improve the safety and stability of rescue grasping.
文摘The original intention of the algorithmic recommender system is to grapple with the negative impacts caused by information overload,but the system also can be used as"hypernudge",a new form of online manipulation,to inten⁃tionally exploit people's cognitive and decision-making gaps to influence their decisions in practice,which is particu⁃larly detrimental to the sustainable development of the digital market.Limiting harmful algorithmic online manipula⁃tion in digital markets has become a challenging task.Globally,both the EU and China have responded to this issue,and the differences between them are so evident that their governance measures can serve as the typical case.The EU focuses on improving citizens'digital literacy and their ability to integrate into digital social life to independently ad⁃dress this issue,and expects to address harmful manipulation behavior through binding and applicable hard law,which is part of the digital strategy.By comparison,although there exist certain legal norms that have made relevant stipula⁃tions on manipulation issues,China continues to issue specific departmental regulations to regulate algorithmic recom⁃mender services,and pays more attention to addressing collective harm caused by algorithmic online manipulation through a multiple co-governance approach led by the government or industry associations to implement supervision.
基金supported by the National Natural Science Foundation of China(Nos.21904095,22004089)Peiyang Talents Project of Tianjin University+1 种基金Young Thousand Talented ProgramProgram of Tianjin Science and Technology Major Project and Engineering(No.19ZXYXSY00090)。
文摘Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold great promise as miniature detectives capable of detecting mi RNAs within cells.However,current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection,particularly within the intricate confines of the cellular microenvironment,due to interference with biological autofluorescence,off-target effects,and a lack of spatiotemporal control.Here,we have designed a dual-stimuli responsive DNA tracker,synergistically utilizing specific intracellular cues and external triggers,which enables spatiotemporal-controlled and precise detection and imaging of miRNAs"on demand".The tracker,which combines zeolitic imidazolate framework-67(ZIF-67)and unique hairpin DNA structures,effectively anchored onto the ZIF-67 through electrostatic interactions,remains in a dormant state until activated by abundant cellular ATP,resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region.Subsequent irradiation triggers specific recognition of the target miRNA.The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal mi RNA detection and exhibits excellent biocompatibility,enabling specific mi RNA recognition"on demand"within cancer cells.This research presents a reliable mi RNA imaging platform in the intricate cellular environment,opening up the possibilities for precise biomedical analysis and disease diagnosis.
基金financially supported by the Shenzhen Science and Technology Project(Project Nos.JCYJ20220818102201003,JCYJ20220818100001002)the Shenzhen Sustainable Development Special Project(Project No.KCXFZ20230731094500001)+1 种基金the National Natural Science Foundation of China(Project Nos.51975597,52175446)the Natural Science Foundation of Guangdong Province(Project No.2022B1515020011)。
文摘Magnetically responsive microstructured functional surface(MRMFS),capable of dynamically and reversibly switching the surface topography under magnetic actuation,provides a wireless,noninvasive,and instantaneous way to accurately control the microscale engineered surface.In the last decade,many studies have been conducted to design and optimize MRMFSs for diverse applications,and significant progress has been accomplished.This review comprehensively presents recent advancements and the potential prospects in MRMFSs.We first classify MRMFSs into one-dimensional linear array MRMFSs,two-dimensional planar array MRMFSs,and dynamic self-assembly MRMFSs based on their morphology.Subsequently,an overview of three deformation mechanisms,including magnetically actuated bending deformation,magnetically driven rotational deformation,and magnetically induced self-assembly deformation,are provided.Four main fabrication strategies employed to create MRMFSs are summarized,including replica molding,magnetization-induced self-assembly,laser cutting,and ferrofluid-infused method.Furthermore,the applications of MRMFS in droplet manipulation,solid transport,information encryption,light manipulation,triboelectric nanogenerators,and soft robotics are presented.Finally,the challenges that limit the practical applications of MRMFSs are discussed,and the future development of MRMFSs is proposed.
基金the National Natural Science Foundation of China(Nos.11832005,12372042,12232011)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)+1 种基金the Fundamental Research Funds for the Central Universities(No.NS2023002)State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and Astronautics)(No.MCAS-S-0223K04).
文摘The quantity of space debris on Earth orbit has escalated tremendously in recent years, presenting a significant hazard to human space operations. It is urgent to develop effective measures to capture and remove various space debris. For this purpose, this paper presents a tendon-actuated flexible deployable manipulator. The flexible manipulator consists of several deployable units connected by Cardan joints and actuated by tendons. Compared with the present technologies for capturing space debris such as rigid robotic arm or flying net, this flexible manipulator is deployable, reusable, lightweight and applicable to the capture of large space debris. In order to investigate its deployment dynamics, an accurate dynamic model of the flexible manipulator is established based on the natural coordinate formulation (NCF) and the absolute nodal coordinate formulation (ANCF). Subsequently, numerical simulations are carried out to study the effects of system parameters and the base satellite on its deployment dynamics. Finally, ground experiments for both deployment and bending of the flexible manipulator are conducted to verify its effectiveness and feasibility.
基金supported by National Natural Science Foundation of China(Nos.12072381,22072185,21805315)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011812)Science and Technology Innovation Project of Guangzhou(No.202102020263).
文摘On-demand droplet manipulation plays a critical role in microfluidics,bio/chemical detection and microreactions.Acoustic droplet manipulation has emerged as a promising technique due to its non-contact nature,biocompatibility and precision,circumventing the complexities associated with other methods requiring surface or droplet pretreatment.Despite their promise,existing methods for acoustic droplet manipulation often involve complex hardware setups and difficulty for controlling individual droplet amidst multiple ones.Here we fabricate simple yet effective acoustic tweezers for in-surface and out-of-surface droplet manipulation.It is found that droplets can be transported on the superhydrophobic surfaces when the acoustic radiation force surpasses the friction force.Using a two-axis acoustic tweezer,droplets can be maneuvered along arbitrarily programmed paths on the surfaces.By introducing multiple labyrinthine structures on the superhydrophobic surface,individual droplet manipulation is realized by constraining the unselected droplets in the labyrinthine structures.In addition,a three-axis acoustic tweezer is developed for manipulating droplets in three-dimensional space.Potential applications of the acoustic tweezers for micro-reaction,bio-assay and chemical analysis are also demonstrated.
基金financial supports from the National Natural Science Foundation of China(Grant Nos.51925503&52105575)the Fundamental Research Funds for the Central Universities(Grant No.QTZX23063)+2 种基金the Aeronautical Science Foundation of China(Grant No.2022Z073081001)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232028)the Open Research Funds of State Key Laboratory of Intelligent Manufacturing Equipment and Technology(Grant No.IMETKF2024008).
文摘The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of existing works remain complex as they usually require the integration of multiscale structures.Here,we introduce phase modulation into the infrared camouflage metasurfaces with metal-dielectric-metal configuration,enabling them to achieve camouflage across more bands.Based on this strategy,a simple but effective single-layer cascaded metasurface is demonstrated for the first time to achieve low reflection at multi-wavelength lasers,low infrared radiation in atmospheric windows,and broadband thermal management.As a proof-of-concept,a 4-inch sample with a minimum linewidth of 1.8μm is fabricated using photolithography.The excellent infrared multispectral camouflage performance is verified in experiments,showing low reflectance in 0.9–1.6μm,low infrared emissivity in mid-wavelength infrared(MWIR)and long-wavelength infrared(LWIR)bands,and high absorptance at the wavelength of 10.6μm.Meanwhile,broadband high emissivity in 5–8μm can provide high-performance radiative heat dissipation.When the input power is 1.57 W·cm^(-2),the surface/radiation temperature of the metasurface decreases by 5.3℃/18.7℃ compared to the reference.The proposed metasurface may trigger further innovation in the design and application of compact multispectral optical devices.
基金supported by the National Natural Science Foundation of China(Nos.52025132,U24A20205,52303373,21621091,22021001,and 22121001)the China Postdoctoral Science Foundation(No.2024M763174)+2 种基金the 111 Project(Nos.B17027,B16029)the Natural Science Foundation of Fujian Province of China(No.2022J02059)the New Cornerstone Science Foundation through the Xplorer Prize。
文摘Controllable liquid manipulation is of paramount scientific and technological importance in various fields,such as the chemical industry,biomedicine,and agricultural production.Magnetic actuation,characterized by rapid,contactless,and environmentally benign operation,has emerged as a promising approach for precise liquid control.However,conventional magnetic strategies typically govern droplet movement on open surfaces,facing limitations such as restricted liquid volumes,uncertain flow paths,and inevitable evaporation,thereby constraining their broader practical applications.Recently,a variety of magneticdriven strategies have been developed to dynamically regulate liquids within enclosed spaces,especially through physicochemical mechanisms.These approaches provide efficient control over liquid behavior by leveraging magnetically induced chemical changes,structural deformations,and dragging motions,opening new opportunities for flexible and versatile fluid management.This review explores the design and mechanisms of magneto-responsive confined interfaces for the manipulation of nonmagnetic liquids,highlighting key advancements and potential applications including liquid valves,liquid mixing,liquid flow regulation,and liquid pumping.Finally,the existing challenges and future prospects in this field are presented.
基金supported by Shanghai Municipal Science and Technology Major Project(2021SHZDZX)also in part supported by the Science and Technology Commission of Shanghai Municipality(20DZ2220400).
文摘Microassembly platforms have attracted significant attention recently because of their potential for developing microsystems and devices for a wide range of applications.Despite their considerable poten-tial,existing techniques are mainly used in laboratory research settings.This review provides an over-view of the fundamentals,techniques,and applications of microassemblies.Manipulation techniques based on magnetic,optical,acoustic fields,and mechanical systems are discussed,and control systems that rely on machine vision and force feedback are introduced.Additionally,recent applications of microassemblies in microstructure fabrication,microelectromechanical operation,and biomedical engi-neering are examined.This review also highlights unmet technical demands and emerging trends,as well as new research opportunities in this expanding field of research driven by allied technologies such as microrobotics.
