Small Cycle Research Articles

Benchmarks defining high-quality sperm in the common marmoset (Callithrix jacchus).

Common marmosets (Callithrix jacchus) are increasingly recognized as valuable nonhuman primates (NHPs) for biomedical research due to their small size and short reproductive cycle and lifespan relative to other NHP species. Maximizing the utility of captive research marmosets, including genetically manipulated animals, will require the use of assisted reproductive techniques (ART) including manipulation, storage, and sharing of marmoset sperm. Here, we identify characteristics of high-quality semen samples and validate a simple method for selecting high-quality sperm. Computer-assisted sperm analysis (CASA) was used to evaluate sperm quality in semen samples collected from 44 marmosets and assessed the use of the swim-up method for the selection of high-quality sperm was also tested in half the samples as a potential means to optimize in vitro fertilization or intrauterine insemination. For each reference parameter, samples at or below the 5th percentile were categorized as abnormal sperm, while those above the 5th percentile were considered to be normal. Among normal samples, those at or above the 50th percentile were categorized as high-quality. High-quality semen samples exhibited the following characteristics: semen volume ≥ 30µL; sperm count ≥ 107/ejaculate; total motility ≥ 35%; and normal morphology ≥ 5%. Sperm isolated by swim-up exhibited superior sperm progressive motility (19.7%±4.5vs. 5.6%±2.1; P=0.01) and normal morphology (13.1±1.59vs. 7.65±1.1; P<0.001) compared with unselected sperm. This study defines robust, statistically supported reference values for evaluating marmoset semen samples to assist with the identification of optimal sperm donors and the selection of high-quality sperm samples for assisted reproduction. Ultimately, these reference values combined with a validated selection method will contribute to consistent standards for the international sharing of genetically diverse and/or gene-edited marmoset sperm for research and reproduction.

CEEMDAN combined wavelet denoising improved the MW cycle slip detection algorithm

In the preprocessing of high-precision navigation and positioning data, the most widely used MW combination cycle slip detection method is greatly affected by pseudorange noise. It has issues such as missing small cycle slips and failing to promptly reset the recursive averaging process after cycle slip detection failure, which leads to subsequent threshold divergence. This paper proposes an improved MW combination cycle slip detection method based on Complete Ensemble Empirical Mode Decomposition (CEEMDAN), permutation entropy, and wavelet denoising, which uses CEEMDAN to decompose the cycle slip signal into a series of intrinsic modal functions (IMFs) and then selects the IMFs that require denoising through the permutation entropy algorithm, and the wavelet denoising technique is combined to eliminate the residual noise further, so that the noise can be removed more accurately. Experimental results show that compared with the original MW algorithm, the proposed improved method can effectively reduce the influence of pseudo-range noise, and reduce the false detection rate of cycle slip from 1.6% and 6–0%. All small period slips can be successfully detected in complex noise environments, avoiding the missed detection of the original MW algorithm and the related threshold divergence problems.

Quasi‐Z‐source interleaved DC‐DC converter for fuel cell vehicle application

AbstractIn this study, a step‐up DC‐DC converter with a combination of a two‐phase interleaved structure and a quasi‐Z impedance network is proposed for fuel cell vehicle application. The operation of the converter in a small duty cycle (0 &lt; D &lt; 0.5) reduces the conductive losses of the switches and as a result increases the efficiency of this converter compared to conventional boost converters. Also, due to the common ground between the input and output, unlike the floating interleaved boost converter (FIBC) and the parallel input‐series output converter (PISO), it does not face the problem of imposing additional EMI on the converter circuit. This converter has a low input current ripple, suitable voltage gain for fuel cell vehicles system, as well as high reliability due to the ability to operate with one phase in case of failure in the other phase. It can be a suitable candidate for practical application in fuel cell vehicles. The principles of operation and the main characteristics of the converter such as voltage gain, input current ripple, and voltage and current stress of the elements are explained and also a 120‐W experimental prototype with 12‐V input voltage and 60‐V output voltage is made to validate the theoretical analysis results.

Maximal canards in a slow–fast Rosenzweig–MacArthur model with intraspecific competition among predators

Using geometric singular perturbation theory, this paper investigates the canard phenomenon of a slow–fast Rosenzweig–MacArthur model. The model incorporates intraspecific competition among predators, assuming predator reproduction occurs much slower than prey. We demonstrate the occurrence of maximal canards between attracting and repelling slow manifolds as a bifurcation parameter varies. Additionally, we derive an analytic expression to approximate the bifurcation parameter value at which a maximal canard occurs. The method employed for this analysis relies on the blowup method. This involves finding a quasihomogeneous blowup map to desingularize the nonnormally hyperbolic point. Subsequently, charts are utilized to express the blowup in local coordinates, calculate local data, investigate the dynamics of the blown-up vector fields, and establish connections across charts. Furthermore, we provide numerical simulations to illustrate the canard explosion phenomenon in the model. Through parameter variation, we observe that the model transitions from a small amplitude limit cycle to small amplitude canard cycles (canards without a head), then to large amplitude canard cycles (canards with a head), and finally to a large amplitude relaxation cycle.

Heterostructured fluoride-based solid electrolytes engineered by grain boundary softening and bonding for sustainable Na metal batteries

Fluoride solid electrolytes stand out as promising candidates for high-energy-density solid-state batteries owing to their inherent structural and air stability. However, their application in sodium based batteries has been hindered by their low ionic conductivity. Here, we propose a heterostructured fluoride-based solid electrolyte engineered by grain boundary softening and bonding for sustainable Na metal batteries. By leveraging a low-melting-point chloride eutectic mixture NaCl-1.1AlCl3 (NA), we achieve the in situ activation of sodium ion transport at the grain boundaries of Na3GaF6 (NGF), with the formation of a molten salt interphase primarily composed of NaAlCl4. This process effectively softens the edges of NGF and heals the intergranular voids. The NA decorated NGF electrolyte exhibits the significantly enhanced ionic conductivities of 2.7 × 10–4 S/cm at 60 °C and 2.45 × 10–5 S/cm at room temperature, representing two orders of magnitude improvement over pure NGF. The chloride shell does not degrade the wide electrochemical window and air stability of NGF. This electrolyte relies on a unique "self-protection" mechanism when cycling with sodium metal anode. The molten salt phase can evolve into a compact NaCl protective shell and an Na-Al conductive inner layer with tight contact with Na anode. This dual-layer structure mitigates the side reaction with NGF host, homogenizes the current flow, and suppresses the growth of sodium dendrites. The corresponding Na//Na symmetric cells display the small voltage polarization and stable cycling performance for over 1000 h. The solid-state Na//FeF3 batteries deliver a high capacity of 308 mAh/g and sustain for at least 100 cycles with high capacity retention based on conversion reaction.

Facies variability and depositional cyclicity in central Northern Switzerland: insights from new Opalinus Clay drill cores

The Opalinus Clay, a silty to sandy claystone formation, Early to Middle Jurassic (Toarcian and Aalenian) in age, has been selected as the host rock for deep subsurface disposal of radioactive waste in Switzerland. Over the past thirty years, numerous geotechnical, mineralogical, and sedimentological studies have been conducted on the Opalinus Clay within the framework of the Nagra (National Cooperative for the Disposal of Radioactive Waste) deep drilling campaigns and the Mont Terri Project, an international research program dedicated to the study of claystone. The present study aims to unravel the variability of the lateral and vertical facies of the Opalinus Clay in central Northern Switzerland and to place this variability in a regional and basinal context. Analyses of new cores drilled in central Northern Switzerland, including petrographic, mineralogical (X-ray diffraction, multi-mineral interpretation), geochemical (X-ray fluorescence), statistical (non-metric multidimensional scaling analysis), and bedding dip and azimuth data, shed new light on the depositional facies and the spatial and temporal variability of the Opalinus Clay. Petrographic descriptions encompass nine new drill cores using a revised subfacies/facies classification scheme based on texture (colour, grain size, bedding) and composition (mineralogy). Particularly, one new subfacies (SF6) is described and interpreted as mass-wasting deposits. The drill cores are correlated laterally using specific marker horizons. This correlation is achieved by combining thorough facies investigations with lithostratigraphy, biostratigraphy, and chemostratigraphy. Six to seven small coarsening-upward cycles and two long-term coarsening-upward sequences can be interpreted as regressive trends. The observed trends are influenced by the interplay between sediment supply, eustatic sea level change, synsedimentary subsidence, but also the palaeogeographic configuration in an epicontinental sea, provenance and delivery of sediments, current dynamics and climate change. Finally, combined results show that the current dynamics in the Opalinus Clay has been underestimated until now and new depositional models, including the occurrence of drift deposits, are discussed.

Quantum-assisted rendezvous on graphs: explicit algorithms and quantum computer simulations

Abstract We study quantum advantage in one-step rendezvous games on simple graphs analytically, numerically, and using noisy intermediate-scale quantum (NISQ) processors. Our protocols realise the recently discovered (Mironowicz 2023 New J. Phys. 25 013023) optimal bounds for small cycle graphs and cubic graphs. In the case of cycle graphs, we generalise the protocols to arbitrary graph size. The NISQ processor experiments realise the expected quantum advantage with high accuracy for rendezvous on the complete graph K 3. In contrast, for the graph 2 K 4 , formed by two disconnected 4-vertex complete graphs, the performance of the NISQ hardware is sub-classical, consistent with the deeper circuit and known qubit decoherence and gate error rates.

Coexistence of Algebraic Limit Cycles and Small Limit Cycles of Two Classes of Near-Hamiltonian Systems with a Nilpotent Singular Point

Coexistence of Algebraic Limit Cycles and Small Limit Cycles of Two Classes of Near-Hamiltonian Systems with a Nilpotent Singular Point

Enhancing TDCP-specified GNSS/INS tightly coupled filter robustness in cascaded for low-cost urban applications

Abstract Integration of global navigation satellite systems (GNSS) with inertial navigation systems (INS) is commonly employed to enhance navigation performance. However, conventional integrated algorithms suffer from low-quality GNSS measurements due to either inaccurate pseudorange or difficulty in ambiguity resolution when utilizing carrier phase (CP) measurements in urban environments. We propose a new time-differenced CP (TDCP-) specified GNSS/INS tightly coupled integration algorithm for low-cost urban applications. The proposed method employs a dual-rate filter scheme, wherein the potential of TDCP observations and INS-derived positions are fully harnessed for state estimation with PR outlier inhibition and CP small cycle slip repair. Field test results in urban environments demonstrate that the integrated navigation scheme proposed is superior to conventional algorithms, with an average improvement of about 13.4%, 19.2%, and 25.5% in position, velocity, and attitude, respectively.

Digital twin Bayesian entropy framework for corrosion fatigue life prediction and calibration of bridge suspender

This paper proposes an intelligent digital twin framework for corrosion fatigue life prediction and calibration of suspender wires integrated with mechanism-driven, sensor-driven, and information fusion. A general probabilistic information fusion strategy is constructed to handle entropy-based external constraints and classical Bayesian updating. Statistical moment, range bound, and point data are considered to investigate the effect of various types and sequences of information. A small-time domain fatigue crack growth model is proposed to overcome the limitations of traditional cycle-based methods, which can capture the large and small cycles of random fatigue stress. The virtual sensor-based stress time-history response is obtained under different traffic flow densities through digital twin finite element model of a suspension bridge. The results show that with and without considering interval bound leads to different fatigue life prediction results, especially for statistical moment data fusion, and the maximum difference is approximately 54%. The average prediction life of suspender wires is gradually close to the actual service life as crack observations increase. The standard deviations of the corrosion fatigue life decrease by 88%, when simultaneously integrating moment, interval, and point data.

Cardionogen-1, a novel small molecule, induces apoptosis and cell cycle arrest in huh-7 hepatoma cells

Cardionogen-1, a novel small molecule, induces apoptosis and cell cycle arrest in huh-7 hepatoma cells

A Polynomial System of Degree Four with an Invariant Square Containing At Least Five Limit Cycles

We consider a class of polynomial systems of degree four with four real invariant straight lines that form a square, called this an invariant square, and also that contains in its interior at least five small amplitude limit cycles for a certain choice of the parameters. Moreover, we will obtain the necessary and sufficient conditions for the critical point inside the square to be a center.

Network Design and Control: Shape and Topology Optimization for the Turnpike Property for the Wave Equation

The optimal control problems for the wave equation are considered on networks. The turnpike property is shown for the state equation, the adjoint state equation as well as the optimal cost. The shape and topology optimization is performed for the network with the shape functional given by the optimality system of the control problem. The set of admissible shapes for the network is compact in finite dimensions, thus the use of turnpike property is straightforward. The topology optimization is analysed for an example of nucleation of a small cycle at the internal node of network. The topological derivative of the cost is introduced and evaluated in the framework of domain decomposition technique. Numerical examples are provided.

Hopf bifurcation and limit cycle of the two‐variable Oregonator model for Belousov–Zhabotinsky reaction

This paper is concerned with a two‐variable Oregonator model for Belousov–Zhabotinsky Reaction. Llibre and Oliveira (2022) proved that Oregonator model with an unstable node or focus has at least one limit cycle in the positive quadrant, and the system has a unique stable limit cycle for some values of the parameters. It is shown in the present paper that the positive equilibrium is not a center, and that if the system has a positive equilibrium which is a weak focus, then its order is at most 2. There exist some parameter values such that system has small limit cycle around the positive equilibrium.

Paralleled Variable Inductor Phase-Shifted Full-Bridge Converter With Full-Load Range ZVS and Low Duty Cycle Loss

This paper presents a new phase-shifted full-bridge topology using a new variable inductor. In this topology, a variable inductor is connected in parallel with a near-ideal transformer. The ZVS of the switches is achieved over the full load range using the parallel current provided by the variable inductor. And the adjustable parallel current reduces conduction losses. Under the orthogonal DC magnetic potential, the variable inductor has similar characteristics to the saturated inductor, which is beneficial to reduce the conduction loss caused by the parallel current. Since the topology has no series inductor and the leakage inductor is extremely small, the proposed converter has the advantages of extremely small duty cycle loss, larger transformer turns ratio, smaller primary current stress, smaller secondary voltage stress, and smaller output current ripple, which are beneficial to improve the efficiency and frequency of the converter. An experimental platform was established. Theoretical analysis and experimental verification were carried out.

A novel method for cycle slip detection and restoration of BDS carrier phase

The chief purpose of this present study is to develop a new approach to cycle slip detection and restoration of the BeiDou Navigation Satellite System (BDS) carrier phase. Based on the RAIM algorithm in the application of aviation safety, we extend the application to ensure the precision of the carrier phase. To stand-alone receivers of a low-cost single frequency, carrier phase data is made different between adjacent epochs. Then least-square residuals were to design a RAIM scheme with differential carrier phase data to find out the epoch with cycle slip, and finally repair cycle slip by Chebyshev polynomial. Results indicate that the approach can detect cycle slip effectively and both big cycle slip and small cycle slip could be repaired.

Genre and stylistic typology of the preludes from V. Zaderatsky’s cycle “24 Preludes and Fugues”

Statement of the problem. Small cycles from “24 Preludes and Fugues” (1937–1939) by V. P. Zaderatsky (1891–1953) represent an original compositional and dramaturgical phenomenon. Often it is the preludes that are the bearers of the most vivid, relief themes and images and determine the content-semantic dominance of the small and large polyphonic cycle as a whole, while the fugues are dramaturgically weaker and complement or shade the preludes. This allows us to hypothesize about the important role of preludes in the polyphonic cycle of V. P. Zaderatsky. Recent research and publications. The latest studies demonstrate a significant interest in Ukrainian polyphonic music, as evidenced by the recently defended dissertations by L. Tsyganyuk (2023), S. Postovoitova (2024) on the material of the polyphonic cycles of V. Bibik, A. Karamanov, M. Skoryk, O. Yakovchuk, I. Pyaskovskyi, B. Stronko, V. Zaderatsky. O. Ostapchuk (2023), and S. Postovoitova (2024) are currently showing interest in “24 Preludes and Fugues” by V. Zaderatsky, whose work is returning “from oblivion” (Ostapchuk, 2023). In S. Postovoitova’s dissertation, the large polyphonic cycle is studied from the aspect of compositional and dramaturgical unity, while the fugue itself is considered as the conceptual center of the small and large polyphonic cycles. With a comprehensive disclosure of the features of fugues, much less attention is paid to the preludes, although they can often be considered as carriers of the leading images of the cycle. Objectives, methods, and novelty of the research. The scientific novelty of the research consists in the creation of a genre-stylistic typology of the preludes of the large polyphonic cycle of V. Zaderatsky, which led to the setting of the main purpose – to identify the genre-stylistic affiliation of the preludes of the cycle to a certain stable type. This led to the involvement of the following methods: structural-functional; genre-stylistic analysis; typological; comparative. Results and conclusions. The analysis has shown that the most important group of preludes demonstrates mixed genre parameters (toccata, scherzo, etude), among others – groups of lyricalnocturne, pastoral, scherzo-fairytale (with a hidden plot), gloomy impromptu, etude preludes. All of them illustrate the composer’s attraction to rationalistic structures: whole-tone scales, polymetry (different meters in the left-hand and right-hand parts), complex polyrhythms, which testify to the clearly constructive nature of the design of most of the Preludes.

Detection and repair of BDS six-frequency cycle slips based on recursive filtering and integer constraint method

The multi-frequency signals of the Beidou system are very helpful for positioning, but in data processing, the detection and repair of multi-frequency cycle slips also face certain challenges. A recursive filtering and integer constraint cycle slip detection and repair method for the Beidou six-frequency is proposed in this paper. This method utilises five sets of combination coefficients of six-frequency and three sets of dual-frequency combinations, and detects and repairs cycle slips through integer constraints of cycle slip estimation. The proposed method has been validated by data with a sampling rate of 1 Hz, and can detect the position and size of cycle slips at various frequencies, whether it is random cycle slips or small cycle slips of equal size less than 2 cycles, with a detection success rate of 100%.

GPS/BDS triple-frequency cycle slip detection and repair based on moving window global search method

Cycle slip detection and repair are crucial steps in achieving high accuracy in Global Navigation Satellite System (GNSS) data processing. The use of Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) triple frequency observations allows for more accurate detection and repair of cycle slips compared to single or dual frequency. This study presents a moving window global search method by selecting three sets of combined coefficients to construct geometry-free (GF) models to minimize the influence of the ionosphere, using a moving window to update the standard deviation of cycle slip estimation, applying the "3 σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upsigma$$\\end{document}" criterion to constrain the range, and utilizing a global search method to detect and repair triple-frequency cycle slips. Through five sets of 1 Hz GNSS data experiments, the results demonstrate the effectiveness of this method in determining the position and size of triple-frequency cycle slips while avoiding multi-value problems. The detection success rate for GPS ranges from 98.0 to 100.0%, while BDS ranges from 92.0 to 100.0%. On average, GPS achieves a detection rate of 99.2%, and BDS reaches 96.7%, which is 0.8% and 1.8% higher than the direct rounding method, respectively. Compared to existing methods, it is also effective for the vast majority of small cycle slips within 2 cycles.

Concept and behavior of a novel long-period isolation bearing with variable stiffness

To reduce the effect of train-induced vibration on the structure and improve the serviceability of structures, this study proposes a novel isolation bearing with a simple configuration and low cost, having a wide market prospect. Compared with bearing with constant stiffness, the novel bearing can achieve a broadband vibration isolation effect. Based on quasi-static tests, the behavior of the bearing is investigated, and the analytical hysteresis model of the bearing is derived and validated. Furthermore, comprehensive on-site assessments amidst multi-source traffic vibration scenarios are conducted to validate the vibration mitigation of the isolation bearing. The findings reveal that while at varying preloads and amplitudes, the hysteretic properties remain remarkably stable, except in the case of small amplitude cycles. The theoretical hysteresis model aligns closely with the test result, accurately capturing the cyclic behavior. The bearing significantly reduces the response of structures under multi-source transport vibrations.