Auxiliary Ring Research Articles

On-Chip Photonic Localization in Aharonov-Bohm Cages Composed of Microring Lattices.

Flatband localization endowed with robustness holds great promise for disorder-immune light transport, particularly in the advancement of optical communication and signal processing. However, effectively harnessing these principles for practical applications in nanophotonic devices remains a significant challenge. Herein, we delve into the investigation of on-chip photonic localization in AB cages composed of indirectly coupled microring lattices. By strategically vertically shifting the auxiliary rings, we successfully introduce a magnetic flux of π into the microring lattice, thereby facilitating versatile control over the localization and delocalization of light. Remarkably, the compact edge modes of this structure exhibit intriguing topological properties, rendering them strongly robust against disorders, regardless of the size of the system. Our findings open up new avenues for exploring the interaction between flatbands and topological photonics on integrated platforms.

Voltage-tunable optical parametric oscillator with an alternating dispersion dimer integrated on a chip

Optical parametric oscillators enable the conversion of pump light to new frequency bands using nonlinear optical processes. Recent advances in integrated nonlinear photonics have led to the creation of compact, chip-scale sources via Kerr-nonlinearity-induced parametric oscillations. While these sources have provided broadband wavelength tuning, the ability to tune the emission wavelength via dynamically altering the dispersion has not been attained so far. Here we present a voltage-tunable, on-chip integrated optical parametric oscillator based on an alternating-dispersion dimer, allowing us to tune the emission over nearly 20 THz near 1550 nm. Unlike previous approaches, our device eliminates the need for a widely tunable pump laser source and provides efficient pump filtering at the drop port of the auxiliary ring. Integration of this scheme on a chip opens up the possibility of compact and low-cost voltage-tunable parametric oscillators with diverse application possibilities.

Investigation of Personal Dosimeter Loss Case and Measures to Prevent Loss

Purpose: It is intended to improve the management efficiency of personal dosimeters by analyzing and sharing personal dosimeter loss cases and loss prevention measures. Materials and Methods: From 2017 to 2021, data on the number of lost personal dosimeters were collected at large hospitals, and the number of personal dosimeters issued and lost were investigated. Results: In order to prevent loss by institution, methods such as the use of auxiliary rings, contact stickers and dosimeter necklaces were implemented. Conclusion: Hospitals are a business that frequently changes clothes, such as surgical gowns and work clothes, so there is a lot of loss. In addition, it was confirmed that the loss rate increases as the number of personal dosimeters issued increases.

Study on the bandgap and directional wave propagation mechanism of novel auxiliary semicircle rings lattices

In this study, a novel auxiliary semicircle rings lattice is proposed, and the proposed structure consists of connecting ligaments and auxiliary semicircle rings on ligaments. The bandgap and wave propagation characteristics of the proposed structure are analyzed. The generation mechanism of bandgap is carefully studied according to the vibration shape of the structure. Based on the Bloch's theorem and the finite element method, the dynamic model of the structure is solved to explore the wave behavior in the lattice. Then, the effects of different semicircle directions, the number of semicircle rings and the size of semicircle rings on the bandgap width and position are analyzed. In particular, we calculated the group velocity to analyze the influence of the direction of the semicircle rings on the directional frequency related energy flow in the structure. We also simulated the directional wave behavior in a finite-size lattice. It was found that in the proposed structure, the elastic wave with a specific frequency propagated along a certain direction. This study provides an ideological guidance for the topology design of metamaterials with directional wave propagation.

A Rapid Temporal Bone Localization Method Based on Machine Visual Detection Markers

The number of hearing-impaired people is increasing year by year; robotic cochlear drilling surgery is one of the safest methods to treat deafness. Looking at the issue of low efficiency of temporal bone posture positioning in cochlear implantation robotic drilling, a novel auxiliary ring marker temporal bone positioning method was proposed to improve temporal bone posture positioning efficiency, optimize the operation time, and reduce auxiliary injuries caused by the surgery. First, the temporal bone visual positioning assistant ring was designed based on the requirements for cochlear robotic drilling surgery. The target detection was conducted on the auxiliary ring and image processing and feature point extraction methods were designed. Then, the three-dimensional coordinates of the measured feature points were obtained by binocular vision, and the auxiliary ring and temporal bone postures were estimated. Finally, the auxiliary ring and temporal bone localization methods were validated. The experiment results indicated that the temporal bone was located quickly and effectively in a total time of about 33 ms, which was faster and more accurate than traditional visual localization methods and could satisfy real-time temporal bone localization during surgery. This study can reduce the time of temporal bone visual positioning in cochlear implant drilling operations, greatly improving the robot’s capabilities to extract visual information during the operation, which has a better auxiliary role for future research and applications of the cochlear implant drilling operation.

Creating boundaries along a synthetic frequency dimension

Synthetic dimensions have garnered widespread interest for implementing high dimensional classical and quantum dynamics on low-dimensional geometries. Synthetic frequency dimensions, in particular, have been used to experimentally realize a plethora of bulk physics effects. However, in synthetic frequency dimension there has not been a demonstration of a boundary which is of paramount importance in topological physics due to the bulk-edge correspondence. Here we construct boundaries in the frequency dimension of dynamically modulated ring resonators by strongly coupling an auxiliary ring. We explore various effects associated with such boundaries, including confinement of the spectrum of light, discretization of the band structure, and the interaction of boundaries with one-way chiral modes in a quantum Hall ladder, which exhibits topologically robust spectral transport. Our demonstration of sharp boundaries fundamentally expands the capability of exploring topological physics, and has applications in classical and quantum information processing in synthetic frequency dimensions.

Electromagnetic performance analysis of the umbrella shaping inner rotor coaxial magnetic gear with dual modulation rings

The coaxial magnetic gear is a new type of noncontact transmission mechanism, which avoids the inherent defects of the mechanical gearbox due to gear meshing transmission. To study a coaxial magnetic gear (CMG) with high torque density and low torque ripple to replace the mechanical gear in the semidirect drive wind turbine, a novel umbrella shaping inner rotor CMG (US-CMG) with an auxiliary modulation ring is proposed in this paper. The novel structure adopts a CMG with a dual modulated ring to increase the electromagnetic torque. In addition, the magnetic block of the poled inner rotor is divided into three pieces magnetized by Halbach arrays, and the middle piece is umbrella-shaped to reduce torque ripple. Based on the topology of the US-CMG and the principle of the magnetic field modulation, the operation mechanism of the US-CMG is analyzed. A contrastive analysis among the US-CMG, Halbach magnetized dual-modulator CMG (HM-CMG), and surface-mounted CMG (SM-CMG) is established to identify the performance of the US-CMG. Compared with the SM-CMG, the results show that the electromagnetic torque of the US-CMG has increased by 65.46%, and the torque ripple of the US-CMG is 57.6% of that of the SM-CMG.

Highly reliable Coordinated Control Strategy for Static Frequency Converters applied to Large Synchronous Condensers

A large synchronous condenser can quickly and flexibly implement various functions such as dynamic change in load tracking, realization of peak reduction and valley filling, emergency reserve, frequency modulation, and phase modulation. This type of condenser is typically started using a static frequency converter (SFC). Based on the analysis of the working principle of SFCs, this paper proposes a highly reliable coordinated control method with resynchronization criterion for an SFC. An auxiliary loop is introduced for voltage control at the SFC to realize feedforward of the trigger angle of the rectifier. This method can effectively improve the success rate of grid synchronization of the synchronous condenser and shorten the start-up time. Moreover, when the AC voltage on the grid side drops, the auxiliary ring can automatically reduce the terminal voltage to maintain a stable operation. A comparative experiment was conducted on an RTDS to verify the feasibility and effectiveness of the proposed method.

Photonic non-Bloch quadrupole topological insulators in coupled ring resonators

We investigate the second-order topological phases in a two-dimensional ring resonator array with each plaquette occupied by \ensuremath{\pi} gauge flux and imaginary gauge field. The real and imaginary gauge fields are induced by shifting the displacement and integrating gain or loss into the two half perimeters of the auxiliary rings. The system supports topological corner modes with their emergence being determined by the non-Bloch topological invariant due to skin effects. The bulk modes, exhibiting second-order skin effects in both trivial and nontrivial phases, are accumulated at opposite corners depending on whether clockwise or counterclockwise modes are excited. By introducing an interface with different imaginary gauge fields, we show the bulk modes exist at the interface while the topological corner modes are localized at the physical corners. Furthermore, the skin effects are also presented in the passive ring resonators. The study may find applications in lasers and broadband light trapping.

Development and Investigation of Novel Axial-Field Dual-Rotor Segmented Switched Reluctance Machine

This article presents a new type of axial-field switched reluctance machine (AFSRM) and axial-field dual-rotor segmented switched reluctance machine (ADS-SRM), along with its design methodology. The proposed ADS-SRM is featured by the segmental stator and rotor poles, the auxiliary flux-conductive rings, and the concentrated windings. The yokeless topology reduces the active length of the motor. Besides, the adopted short-end winding layout increases the slot-fill factor and the motor's reliability. First, the basic topology of ADS-SRM is introduced along with its operating principle and various stator/rotor pole combinations. The three-phase 12/8 configuration of ADS-SRM is chosen for further analysis. Then, the design methodology considering the fringing and leakage field effects through the magnetic equivalent circuit (MEC) method is developed, and the flowchart detailing the design procedure is presented. Through the comparison with the conventional yokeless and segmented armature (YASA) topology, ADS-SRM exhibits excellent performance at overload conditions. The prototype is designed and fabricated, and the experimental results verify the motor performance.

Effects of Electric Filed on Electrospray Process: Experimental and Simulation Study

At present, there exists a widely-held view that electric field plays an extremely important role in the electrospray process. Aimed at investigating into the effects of electric field distribution and intensity on the electrospray process and resultant microsphere diameter, a variety of necessary and relevant tests were performed in this study by inviting an auxiliary electrode ring. The three-dimensional electric fields of the electrospray system were simulated, in addition, high-speed photography was adopted to recognize the electrospray modes. The results of a series of electrospray experiments demonstrated that not only electrospray mode but also resultant microsphere diameters are influenced, to a considerable degree, by the electric field. Such simulation results were verified by above-mentioned experiments that from higher electric field intensity comes smaller microsphere diameter, due to the fission caused by the surface charge, and besides, more uniform electric field distribution produces more uniform microsphere diameter.

Total Synthesis of (±)-Leonuketal.

Leonuketal is an 8,9-seco-labdane terpenoid with a unique tetracyclic structure, owing to a diversity-generating biosynthetic C-C bond cleavage event. The first total synthesis of leonuketal is reported, featuring a Ti(III)-mediated reductive cyclization of an epoxy nitrile ether, an unusual ring-opening alkyne formation as part of an auxiliary ring strategy, and the previously undescribed Au(I)-catalyzed cyclization of a β-keto(enol)lactone to assemble the core spiroketal motif.

Positive link gain microwave photonic bandpass filter using Si3N4-ring-enabled sideband filtering and carrier suppression.

Microwave photonic bandpass filters (MPBPFs) are important building blocks in radio-frequency (RF) signal processing systems. However, most of the reported MPBPFs fail to satisfy the stringent real-world performance metrics, particularly low RF insertion loss. In this paper we report a novel MPBPF scheme using two cascaded integrated silicon nitride (Si3N4) ring resonators, achieving a high link gain in the RF filter passband. In this scheme, one ring operates at an optimal over-coupling condition to enable a strong RF passband whilst an auxiliary ring is used to increase the detected RF signal power via tuning the optical carrier-to-sideband ratio. The unique combination of these two techniques enables compact size as well as high RF performance. Compared to previously reported ring-based MPBPFs, this work achieves a record-high RF gain of 1.8 dB in the passband, with a high spectral resolution of 260 MHz. Furthermore, a multi-band MPBPF with optimized RF gain, tunable central frequencies, and frequency spacing tunability is realized using additional ring resonators, highlighting the scalability and flexibility of this chip-based MPBPF scheme.

Primality testing with Gaussian periods

We exhibit a deterministic algorithm that, for some effectively computable real number c , decides whether a given integer n > 1 is prime within time \mathrm {log} n)^6\cdot(2+\mathrm {log\log} n)^c . The same result, with 21/2 in place of 6 , was proved by Agrawal, Kayal, and Saxena. Our algorithm follows the same pattern as theirs, performing computations in an auxiliary ring extension of \mathbb Z/n\mathbb Z . We allow our rings to be generated by Gaussian periods rather than by roots of unity, which leaves us greater freedom in the selection of the auxiliary parameters and enables us to obtain a better run time estimate. The proof depends on results in analytic number theory and on the following theorem from additive number theory, which was provided by D. Bleichenbacher: if t is a real number with 0 < t \le1 , and S is an open subset of the interval (0,t) with \int_S\mathrm d x/x > t , then each real number greater than or equal to 1 is in the additive semigroup generated by S . A byproduct of our main result is an improved algorithm for constructing finite fields of given characteristic and approximately given degree.

Method of axial adjustment for precessional transmissions

Axial adjustment method for precessional transmissions includes compensation error calculation, determination compensator groups, achieved in the form of base and auxiliary rings. The compensator has on the base ring axial canals in which can be placed clamping bolts but the auxiliary ring has axial holes for the screws. The auxiliary ring is formed from increasing sectors - the distance between auxiliary ring stairs and front side of body, from decreasing sectors - the distance between base ring and bottom place, and the closure element - the clearance between gear body and the front surface of the base ring. According to the method of group interchangeability is determined the deviation value of the upper and lower group tolerance and the clearance between lid and body. Then rotating one of the rings is ensured the dimension of the compensator which must match to compensation clearance value and then the compensator is adjusted to required value.

A study on the average wind load characteristics and wind-induced responses of a super-large straight-cone steel cooling tower

As a novel typical wind-sensitive structure, the wind load and wind-induced structural behaviors of super-large straight-cone cooling towers are in an urgent need to be addressed and studied. A super large straight-cone steel cooling tower (189 m high, the highest in Asia) that is under construction in Shanxi Power Plant in China was taken as an example, for which four finite element models corresponding to four structural types: the main drum; main drum + stiffening rings; main drum + stiffening rings + auxiliary rings (auxiliary rings are hinged with the main drum and the ground respectively); and main drum + stiffening rings + auxiliary rings (auxiliary rings are fixed onto the main drum and the ground respectively), were established to compare and analyze the dynamic properties and force transferring paths of different models. After that, CFD method was used to conduct numerical simulation of flow field and mean wind load around the cooling tower. Through field measurements and wind tunnel tests at home and abroad, the reliability of using CFD method for numerical simulation was confirmed. On the basis of this, the surface flow and trail characteristics of the tower at different heights were derived and the wind pressure distribution curves for the internal and external surfaces at different heights of the tower were studied. Finally, based on the calculation results of wind-induced responses of the four models, the effects of stiffening rings, auxiliary rings, and different connecting modes on the dynamic properties and wind-induced responses of the tower structure were derived and analyzed; meanwhile, the effect mechanism of internal suction on such kind of cooling tower was discussed. The study results could provide references to the structure selection and wind resistance design of such type of steel cooling towers.

Synthesis of the four enantiomers of diethyl 1,2-di(N-Boc-amino)propylphosphonates

A simple and efficient synthetic strategy to all four enantiomerically pure diethyl 1,2-di(N-Boc-amino)propylphosphonates has been elaborated starting from the corresponding N-[(R)-(1-phenylethyl)]aziridine-(2S)- and N-[(S)-(1-phenylethyl)]aziridine-(2R)-carboxaldehydes, employing a one-pot three-components Kabachnik-Fields reaction followed by the hydrogenolytic removal of the chiral auxiliary and aziridine ring opening with simultaneous protection of the amino groups as the N-Boc derivatives.

Feasibility of Fiber-Deposition Control by Secondary Electric Fields in Near-Field Electrospinning

Product miniaturization has become a trending technology in a broad range of industries and its development is being pushed by the requirements for complexity and resolution of micromanufactured products. However, there still exists a gap in the manufacturing spectrum for complex three-dimensional (3D) structure generation capabilities with micron and submicron resolution. This paper extends the near-field electrospinning (NFES) process and develops a direct-writing (DW) technology for microfiber deposition with micrometer resolution. The proposed method presented uses an auxiliary electrode to generate an electric field perpendicular to the fiber flight path. This tunable electric field grants the user real-time control of the fiber flight path, increasing the resolution of the deposited structure. The use of an auxiliary electrode ring for fiber manipulation is proposed to further improve control over the deposition process.

COMPARISON OF PROXIMAL IN VITRO TOOTH CONTACTS IN CLASS II RESTORATIONS WITH DIFFERENT RESTORATIVE MATERIALS AND CAVITY SIZES USING A NEW MEASUREMENT DEVICE

This study used a newly developed proximal contact strength (PCS) device to evaluate the tightness of proximal tooth contact for Class II cavity size restoration with different materials using an auxiliary separation ring system. A measurement device based on the equilibrium of forces acted on the clamp rod converts a pull-out force between interdental spaces on a force sensing resistor to express the PCS. This device was designed using dental floss as the test end and can be moved with constant speed during measurement through a bevel gear that transforms the rotation of motor shaft into linear movement of clamp rod. A manikin model was used with 60 artificial first molars in which an mesial occlusal (MO) preparation was ground. Samples were divided into six groups (each n = 10) for simulating amalgam and resin composite restoration with three different cavity sizes. The different cavities were defined using the ratio of the actual isthmus width to the intercuspal width (W) to 1/3, 2/3 and 1. The PCS value in each sample was measured after restoration. The result showed that the mean PCS value and standard deviation were 2283.1 ± 216.5 gf, 2419.1 ± 375 gf and 1737.6 ± 372.7 g for 1/3 W, 2/3 W and W cavities of the amalgam restoration, respectively. The corresponding PCS values were 1178.0 ± 230.4 gf, 1205.8 ± 249.1 gf and 1247.0 ± 157.5 gf for 1/3 W, 2/3 W and W cavities of the resin composite restoration. PCS values with amalgam restoration were larger than those for resin composite restorations under the same cavity size. Large cavity (W) PCS might be lost with amalgam restoration. No significant difference was found in resin composite restoration PCS among the different cavity sizes.

Mid-infrared frequency comb generation in coupled silicon microring resonators

We propose and simulate an on-chip mid-IR frequency comb generator based on the four-wave mixing (FWM) effect in a coupled silicon microring resonator. The resonator is formed by suspended ridge waveguides that are designed to have low group-velocity dispersion. A continuous-wave pump laser coupled into the resonator excites other longitudinal modes of the resonator through FWM-based parametric oscillations. In comparison with the device based on a single-ring resonator, we numerically demonstrate that the pump threshold can be dramatically reduced by introducing an auxiliary ring resonator to compensate the phase mismatch between the pump and the generated comb components. The proposed frequency comb generator has a low pump threshold of ~40mW and a high efficiency of ~25% at the pump power of 100mW.