Shape Anisotropy and Resonance Mode Guided Reliable Interconnect Design for In-plane Magnetic Logic

Dipole coupled nanomagnets controlled by the static Zeeman field can form various magnetic logic interconnects.However, the corner wire interconnect is often unreliable and error-prone at room temperature. In this study, we address this problem by making it into a reliable type with trapezoid-shaped nanomagnets, the shape anisotropy of which helps to offer the robustness. The building method of the proposed corner wire interconnect is discussed,and both its static and dynamic magnetization properties are investigated. Static micromagnetic simulation demonstrates that it can work correctly and reliably. Dynamic response results are reached by imposing an ac microwave field on the proposed corner wire. It is found that strong ferromagnetic resonance absorption appears at a low frequency. With the help of a very small ac field with the peak resonance frequency, the required static Zeeman field to switch the corner wire is significantly decreased by ~21 m T. This novel interconnect would pave the way for the realization of reliable and low power nanomagnetic logic circuits.

The Self-Consistent Nonlinear Theory of Charged Particle Beam Acceleration by Slowed Circularly Polarized Electromagnetic Waves

The relativistic interaction of charged particle beams with a circularly polarized electromagnetic wave propagating along a uniform guiding magnetic field in the tunneling of a dielectric medium is analyzed. The acceleration mechanism and a self-consistent nonlinear theory are presented for the interaction of relativistic charged particle beams with electromagnetic waves. Numerical results show that the beam particle can be efficiently accelerated in the interaction process.

Construction of Multilayer Porous Scaffold Based on Magnetically Guided Assembly of Microfiber

This paper proposes a novel method of magnetically guided assembly to construct multi- layer porous scaffold for three-dimensional cell culture by apply magnetic microfibers. Microfibers are composed of biocompatible and biodegradable alginate solution with homogeneous magnetic nanopar- ticles, which are continuously spun from a microfluidic device by precise pressure control of the syringe pump. Magnetic nanoparticles enable the control of magnetic field on microfibers. Meanwhile, mag- netized device combining with a round permanent magnet are utilized to guide the distribution of spouted microfibers. The device is composed by pure iron wire arrays and wax, which stimulates pow- erful magnetic flux density and magnetic field gradients for the capture and assembly of microfibers. Thus, magnetic microfibers are spun on desired places of the magnetized device by motion control of the micromanipulation robot, and precise locations are adjusted by magnetic force couple with the assist of glass micropipette. Afterwards, microfibers are spatially organized by periodic magnetic force and crossed layer-by-layer to form micro-pore structure with both length and width of 650μm. Finally, the authors construct a multilayer microfiber-based scaffold with high porosity to provide a satisfactory environment for long-term cell culture. The experimental results demonstrate the effectiveness of the proposed method.

Novel compact and lightweight coaxial C-band transit-time oscillator

Compactness and miniaturization have become increasingly important in the development of high-power microwave devices.Based on this rising demand,a novel C-band coaxial transit-time oscillator(TTO)with a low external guiding magnetic field is proposed and analyzed.The proposed device has the following advantages:simple structure,short axial length,high power conversion efficiency,and low external guiding magnetic field,which are of great significance for developing the compact and miniaturized high-power microwave devices.The application of a shorter axial length is made possible by the use of a transit radiation mechanism.Also,loading the opening foil symmetrically to both ends of the buncher helps reduce the external magnetic field of the proposed device.Unlike traditional foils,the proposed opening foil has a circular-hole;therefore,the electron beam will not bombard the conductive foil to generate plasma.This makes it possible to realize long pulse and high repetition rate operation of the device in future experiments.Through numerical calculation and PIC particle simulation,the stability of the intense relativistic electron beam(IREB)and the saturation time of the device are improved by using the conductive foil.The voltage and current of the diode are 548 kV and 11.4 kA,respectively.Under a 0.4-T external guiding magnetic field,a C-band output microwave with a frequency of 4.27 GHz and power of 1.88 GW can be generated.The power conversion efficiency of the proposed device is about 30%.

Acquisition repeatability of MRI radiomics features in the head and neck:a dual-3D-sequence multi-scan study

Radiomics has increasingly been investigated as a potential biomarker in quantitative imaging to facilitate personalized diagnosis and treatment of head and neck cancer(HNC),a group of malignancies associated with high heterogeneity.However,the feature reliability of radiomics is a major obstacle to its broad validity and generality in application to the highly heterogeneous head and neck(HN)tissues.In particular,feature repeatability of radiomics in magnetic resonance imaging(MRI)acquisition,which is considered a crucial confounding factor of radiomics feature reliability,is still sparsely investigated.This study prospectively investigated the acquisition repeatability of 93 MRI radiomics features in ten HN tissues of 15 healthy volunteers,aiming for potential magnetic resonance-guided radiotherapy(MRgRT)treatment of HNC.Each subject underwent four MRI acquisitions with MRgRT treatment position and immobilization using two pulse sequences of 3D T1-weighed turbo spin-echo and 3D T2-weighed turbo spin-echo on a 1.5T MRI simulator.The repeatability of radiomics feature acquisition was evaluated in terms of the intraclass correlation coefficient(ICC),whereas within-subject acquisition variability was evaluated in terms of the coefficient of variation(CV).The results showed that MRI radiomics features exhibited heterogeneous acquisition variability and uncertainty dependent on feature types,tissues,and pulse sequences.Only a small fraction of features showed excellent acquisition repeatability(ICC>0.9)and low within-subject variability.Multiple MRI scans improved the accuracy and confidence of the identification of reliable features concerning MRI acquisition compared to simple test-retest repeated scans.This study contributes to the literature on the reliability of radiomics features with respect to MRI acquisition and the selection of reliable radiomics features for use in modeling in future HNC MRgRT applications.

Dynamic characteristics of a working platform supported by an AMG

A coupled electromechanical dynamic model for a working platform supported by an active magneticguide(AMG)is set up according to the special stiffness and damping theory of maglev system and theunique vibration of the working platform for a machine tool.The dynamic characteristics of a workingplatform supported by an AMG are studied using different groups of control parameters.Results show thatthe dynamic characteristics of the platform system,such as critical vibration frequency,vibration modeand so on,can be improved by adjusting the control parameters.This research offers theoretical supportfor ultra-high-speed and ultra-precise machine working platform designs,including the structure of plat-forms,the design of electromagnets,and the establishment of the control parameters.

Experimental investigation of the relativistic backward wave oscillator with a periodic guiding magnetic field

Experiment is carried out on the accelerator Sinus-700 to investigate the Relativistic Backward Wave Oscillator （RBWO） with a periodic guiding magnetic field. When the strength of the guiding magnetic field, whose period is 4.6 cm, is 0.54 T, a microwave output power of 0.95 GW at 9.1 GHz microwave frequency is achieved. It is shown that the RBWO with a periodic guiding magnetic field is feasible.

Simulation of the relativistic backward wave oscillator with a sinusoidal guiding magnetic field

A simulation is carried out to investigate a relativistic backward wave oscillator （RBWO） with a sinusoidal guiding magnetic field. In the numerical simulation, a microwave output power of 1.33 GW at 9.57 GHz microwave frequency with 33% conversion efficiency is achieved. It is a significant attempt which is helpful for developing a practical high power microwave （HPM） source guided by a permanent magnetic field.

Theoretical investigation of a backward wave oscillator

From the linear Vlasov equation, the theoretical investigation on relativistic backward wave oscillator is performed. The relationship between the microwave power and the guiding magnetic field, which accords with the results of the particle simulation and experiments, is deduced.