GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • IOP Publishing  (14)
  • 2020-2024  (14)
Material
Publisher
  • IOP Publishing  (14)
Person/Organisation
Language
Years
  • 2020-2024  (14)
Year
FID
  • 1
    Online Resource
    Online Resource
    Force and stability mechanism analysis of two types of nonlinear mono-stable and multi-stable piezoelectric energy harvesters using cantilever structure and magnetic interaction
    IOP Publishing ; 2023
    In:  Smart Materials and Structures Vol. 32, No. 3 ( 2023-03-01), p. 035003-
    Details
    In: Smart Materials and Structures, IOP Publishing, Vol. 32, No. 3 ( 2023-03-01), p. 035003-
    Abstract: Nonlinear mono-stable and multi-stable piezoelectric energy harvesters have attracted a lot of attention owing to their broadband frequency spectra and excellent energy harvesting performance. Herein, two types of nonlinear mono-stable, bi-stable, tri-stable, and quad-stable piezoelectric energy harvesters using cantilever structure and magnetic interaction are compared and analyzed. Based on the magnetizing current method, the magnetic force equations are obtained. Calculation results demonstrate that the stability of these harvesters is dependent on the equivalent linear elastic force and the vertical magnetic force. The equilibrium point occurs when the equivalent linear elastic force equals to the vertical magnetic force. The relationship between the number of stable equilibrium points E S and the number of the intersections of the two force curves N I is that E S = ( N I + 1)/2. Experiments are carried out to verify the equivalent linear elastic force, vertical magnetic force, and the number of stable equilibrium points of the fabricated prototypes. The experimental results are consistent with the calculated results, which verifies the correctness of the stability mechanism. Moreover, it is found that the stability mechanism is also applicable to the harvesters with more stable equilibrium points, such as penta-stable and hexa-stable harvesters. This work reveals the stability mechanism of nonlinear mono-stable and multi-stable energy harvesters using cantilever structure and magnetic interaction, and provides technical methods for the design of multi-stable energy harvesters.
    Type of Medium: Online Resource
    ISSN: 0964-1726 , 1361-665X
    URL: Article
    DOI: 10.1088/1361-665X/acb1e3
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2023
    detail.hit.zdb_id: 1115038-5
    detail.hit.zdb_id: 2002821-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Electrothermal shape memory behavior and recovery force of four-dimensional printed continuous carbon fiber/polylactic acid composite
    IOP Publishing ; 2021
    In:  Smart Materials and Structures Vol. 30, No. 2 ( 2021-02-01), p. 025040-
    Details
    In: Smart Materials and Structures, IOP Publishing, Vol. 30, No. 2 ( 2021-02-01), p. 025040-
    Abstract: Four-dimensional (4D) printing technology provides new ideas for the preparation and structural design of multifunctional shape memory composites. Excellent electrothermal shape memory behavior and high shape recovery force are urgently demanded in practical applications. Herein, a continuous carbon fiber reinforced polylactic acid shape memory composite with high strength, high shape recovery force, low-voltage response and excellent electrothermal shape memory behavior was printed using a dual nozzle 3D printer. The effects of specimen thickness, carbon fiber content, and applied voltage on the electrothermal shape memory behavior and shape recovery force were investigated. The reinforcing effect of carbon fiber on 4D printed composite materials was characterized by dynamic mechanical analysis and 3-point bending test. Under electrical thermal stimulation, the shape recovery ratio of most specimens can reach 90%. The shape recovery force of different specimens was obtained by self-designed shape recovery force test system, and the maximum shape recovery force was about 7.38 N. The results show that the introduction of continuous carbon fiber not only significantly enhances the strength of 4D printed composite, but also improves the shape recovery force. The demonstrations of an electrothermal response shape memory deployable claw-device and load-bearing lifting device manifest the potential application in self-actuated intelligent structures.
    Type of Medium: Online Resource
    ISSN: 0964-1726 , 1361-665X
    URL: Article
    DOI: 10.1088/1361-665X/abd912
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2021
    detail.hit.zdb_id: 1115038-5
    detail.hit.zdb_id: 2002821-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Trajectory planning for unmanned skid-steering vehicle
    IOP Publishing ; 2023
    In:  Journal of Physics: Conference Series Vol. 2418, No. 1 ( 2023-02-01), p. 012104-
    Details
    In: Journal of Physics: Conference Series, IOP Publishing, Vol. 2418, No. 1 ( 2023-02-01), p. 012104-
    Abstract: To make a trajectory enough to track unmanned skid-steering vehicles, a planning method is proposed in this paper. The planner consists of velocity planning, curvature planning, and path planning. Subject to the constraints of jerk and acceleration, velocity planning has five possibilities. Then taking curvature constraints into account, curvature planning has three possibilities. And according to the velocity sequence and curvature sequence, the path information of the trajectory can be obtained by the kinematic model. To verify the presented method, a simulation scenario is designed. The test result shows that the proposed method could generate a sufficiently smooth trajectory with satisfying all the constraints, including acceleration, jerk, and curvature.
    Type of Medium: Online Resource
    ISSN: 1742-6588 , 1742-6596
    URL: Article
    DOI: 10.1088/1742-6596/2418/1/012104
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2023
    detail.hit.zdb_id: 2166409-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Cascaded solenoid acceleration of vortex laser-driven collimated proton beam
    IOP Publishing ; 2023
    In:  Plasma Physics and Controlled Fusion Vol. 65, No. 9 ( 2023-09-01), p. 095008-
    Details
    In: Plasma Physics and Controlled Fusion, IOP Publishing, Vol. 65, No. 9 ( 2023-09-01), p. 095008-
    Abstract: Efficient cascaded proton acceleration driven by an intense Laguerre–Gaussian (LG) laser is realized in combined three-dimensional particle-in-cell simulations and CST STUDIO SUITE (CST) simulations. CST simulations show that there is no divergent force component in the transverse direction in the coil center. Therefore, the collimated proton beam driven by the LG laser in the first stage benefits from the uniform beam acceleration in the second stage. By contrast, the proton beam with larger divergence disperses to the outside of the coil because of the divergent force near the coil wire in the Gaussian laser case. Finally, a quasi-monoenergetic proton beam with a higher flux is generated by the LG laser, which is much better than the Gaussian laser case. The obtained proton beam can potentially be used in some special applications, such as proton radiography, fast ignition of fusion targets, biomedical applications, and production of warm dense matter.
    Type of Medium: Online Resource
    ISSN: 0741-3335 , 1361-6587
    URL: Article
    DOI: 10.1088/1361-6587/ace8ba
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2023
    detail.hit.zdb_id: 1473144-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Characterization and nonlinear models of bending extensile/contractile pneumatic artificial muscles
    IOP Publishing ; 2021
    In:  Smart Materials and Structures Vol. 30, No. 2 ( 2021-02-01), p. 025024-
    Details
    In: Smart Materials and Structures, IOP Publishing, Vol. 30, No. 2 ( 2021-02-01), p. 025024-
    Abstract: Pneumatic artificial muscles (PAMs) are compliant fluidic actuators, usually consisting of a tubular bladder, a braided sleeve and end fittings. PAMs have been studied extensively by researchers; however, most previous researches are focused on the axial PAMs. Herein, a pair of nonlinear models were developed based on the principle of virtual work and the force balance analysis. And the two models are applicable to both bending extensile PAMs (BE-PAMs) and bending contractile PAMs (BC-PAMs). In this study, a cyclic bending moment loading experimental method were proposed and conducted with BE-PAMs and BC-PAMs to characterize their deformation and actuation performance and draw their overall relationships of actuation moment to bending curvature and inner pressure. With the experimental results, the validation analysis was carried out to demonstrate the validity of the two models. The energy model can get higher accuracy, while the force balance model could provide more details of the interior and interaction stress conditions. The combination of both can promote the comprehension of non-axial bending PAMs. Moreover, two three-finger soft grippers and a humanoid hand based on BE-PAMs and BC-PAMs were built and tested to investigate their performance on gripping objects. The BE-PAM gripper showed more accommodative gripping performance, whereas, the BC-PAM gripper owned higher gripping force. The humanoid hand combining the merits of both showed excellent flexibility, adaptability and decent load capability in gripping object with various sizes, shapes and materials.
    Type of Medium: Online Resource
    ISSN: 0964-1726 , 1361-665X
    URL: Article
    DOI: 10.1088/1361-665X/abd4b0
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2021
    detail.hit.zdb_id: 1115038-5
    detail.hit.zdb_id: 2002821-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    A mechanical-free designing method for tailoring nonlinearity in bi-stable piezoelectric energy harvesters
    IOP Publishing ; 2023
    In:  Smart Materials and Structures Vol. 32, No. 7 ( 2023-07-01), p. 075002-
    Details
    In: Smart Materials and Structures, IOP Publishing, Vol. 32, No. 7 ( 2023-07-01), p. 075002-
    Abstract: This paper presents a mechanical-free method for providing and tailoring the nonlinear force in bistable piezoelectric energy harvesters (BPEHs). The nonlinear force can be tailored to obtain a lower threshold for inter-well motions, or for the harvester to operate at various excitation levels and frequencies without changing the mechanical structure or the overall assembly. In BPEHs, the nonlinear force is tailored to match a specific excitation level and frequency, and the mechanical structure is designed to achieve higher strain (and thus higher output power). The design of nonlinearity can be separated from the design of the mechanical structure by using magnetic interactions. Hence, the design of nonlinearity is the arrangement of the external magnetic field of the harvester. In this paper, arranging the external magnetic field is achieved by arranging the magnetization distribution of one external magnet. With the locally demagnetizing technique, a uniformly magnetized permanent magnet can be locally demagnetized with desired patterns. The external magnetic field is provided by a locally demagnetized permanent magnet (LDPM). The nonlinear force can be tailored by simply altering the properties of the LDPM. This method converts the design of providing and tailoring the nonlinear force into the design of the LDPMs. For demonstration, we show that without increasing the distance between magnets, the potential barrier of the bistable system is dramatically reduced by using LDPMs. Melnikov’s method is utilized to show that the energy harvesters with LDPMs possess a lower threshold for homoclinic tangency than energy harvesters with a normal magnet. The influence of the parameters of the LDPMs on the energy harvesting performance is studied via simulations and experiments. Results show that without violating the mechanical part, changing the locally demagnetizing patterns can effectively change the harvester’s working frequency and excitation threshold.
    Type of Medium: Online Resource
    ISSN: 0964-1726 , 1361-665X
    URL: Article
    DOI: 10.1088/1361-665X/acd598
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2023
    detail.hit.zdb_id: 1115038-5
    detail.hit.zdb_id: 2002821-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    Research on the Propagation Characteristics of Temperature Anomaly in the Intermediate and Deep Ocean Layers
    IOP Publishing ; 2023
    In:  Journal of Physics: Conference Series Vol. 2486, No. 1 ( 2023-05-01), p. 012094-
    Details
    In: Journal of Physics: Conference Series, IOP Publishing, Vol. 2486, No. 1 ( 2023-05-01), p. 012094-
    Abstract: Due to the lack of observational data, the understanding of propagation characteristics of temperature anomaly is mainly concentrated in the sea surface and the waters above thermocline. Little is known about the propagation characteristics of temperature anomaly in the middle and deep oceans. Based on the gridded Argo data, we analyze the propagation characteristics of temperature anomaly along the isodensity. We found that the temperature anomalies in the middle and deep ocean layers propagate westward at most latitudes, which is the same direction as the propagation of the surface temperature anomaly caused by oceanic Rossby waves. Through the Radon transform, we determined the propagation speeds on different isodensities and explored the relationship of propagation speeds and latitudes and water depth. To the best of our knowledge, this study is the first to explore the propagation characteristics of mid-deep temperature anomalies at the ocean basin scale.
    Type of Medium: Online Resource
    ISSN: 1742-6588 , 1742-6596
    URL: Article
    DOI: 10.1088/1742-6596/2486/1/012094
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2023
    detail.hit.zdb_id: 2166409-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    Design and Implementation of Microservice Secure Communication Framework based on National Secret Algorithm and Dynamic Key
    IOP Publishing ; 2022
    In:  Journal of Physics: Conference Series Vol. 2384, No. 1 ( 2022-12-01), p. 012048-
    Details
    In: Journal of Physics: Conference Series, IOP Publishing, Vol. 2384, No. 1 ( 2022-12-01), p. 012048-
    Abstract: With the acceleration of the pace of the national electricity reform and the wide application of the micro-service architecture, various network threats in the field of information security are increasing, and the power industry has become the “hardest hit area” for cyber attacks. In order to improve the safe implementation of the National Power Grid’s electronic projects and effectively resist the “malicious exploration” of various network threats, this paper proposes a microservice secure communication framework based on the combination of dynamic keys and national secret algorithms for a high concurrency web system based on microservices. The framework uses the national secret SM2 algorithm to generate session-level paired keys and then generates a digital signature through the SM3 algorithm, which effectively guarantees the integrity of the communication. Finally, it extracts the encryption key and encryption offset from the paired keys and uses the SM4 algorithm to encrypt the original request text payload. Timestamps and random numbers are added to each request to prevent tampering and replay attacks effectively. The system framework has been practically applied on the State Grid’s digital capability open platform, which ensures the security of micro-service communication and the safety and efficient transmission of data.
    Type of Medium: Online Resource
    ISSN: 1742-6588 , 1742-6596
    URL: Article
    DOI: 10.1088/1742-6596/2384/1/012048
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2022
    detail.hit.zdb_id: 2166409-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    Identification of Above-Threshold Ionization by Imaging Photoelectrons from Ammonia Molecules in an Intense Femtosecond Laser Field
    IOP Publishing ; 2022
    In:  Chinese Physics Letters Vol. 39, No. 2 ( 2022-02-01), p. 023301-
    Details
    In: Chinese Physics Letters, IOP Publishing, Vol. 39, No. 2 ( 2022-02-01), p. 023301-
    Abstract: The above-threshold ionization process of ammonia molecules induced by a femtosecond laser field at 800 nm is studied in the intensity range from 1.6 × 10 13 to 5.7 × 10 13 W/cm 2 . Channel switching under different laser intensities is observed and identified in the photoelectron kinetic energy spectra of ammonia. Based on the photoelectron kinetic energy distributions and the photoelectron angular distributions, the characteristic peaks observed are exclusively assigned to the multiphoton resonance through certain intermediate states, followed by multiphoton above-threshold ionization.
    Type of Medium: Online Resource
    ISSN: 0256-307X , 1741-3540
    URL: Article
    DOI: 10.1088/0256-307X/39/2/023301
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2022
    detail.hit.zdb_id: 2040565-0
    SSG: 6,25
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    A prediction of hematoma expansion in hemorrhagic patients using a novel dual-modal machine learning strategy
    IOP Publishing ; 2021
    In:  Physiological Measurement Vol. 42, No. 7 ( 2021-07-01), p. 074005-
    Details
    In: Physiological Measurement, IOP Publishing, Vol. 42, No. 7 ( 2021-07-01), p. 074005-
    Type of Medium: Online Resource
    ISSN: 0967-3334 , 1361-6579
    URL: Article
    DOI: 10.1088/1361-6579/ac10ab
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2021
    detail.hit.zdb_id: 2002076-4
    SSG: 11
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...