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Aiming at the problems of complex teaching trajectory, many teaching points and long teaching period, a series robot with direct teaching was developed. The configuration, 3D model and balance scheme of the robot’s mechanical structure are designed. The dynamics of the robot is analyzed by Lagrange method, and the Monte Carlo workspace of the robot is analyzed based on MATLAB platform.

The electron cyclotron maser instability (ECMI) stands as a pivotal coherent radio emission mechanism widely implicated in various astrophysical phenomena. In the context of solar activity, ECMI is primarily instigated by energetic electrons generated during solar eruptions, notably flares. These electrons, upon leaving the acceleration region, traverse the solar atmosphere, forming fast electron beams (FEBs) along magnetic field lines. It is widely accepted that as these FEBs interact with the ambient plasma and magnetic fields, they give rise to radio and hard X-ray emission. Throughout their journey in the plasma, FEBs undergo modifications in their energy spectrum and velocity spatial distribution due to diverse energy loss mechanisms and changes in ambient plasma parameters. In this study, we delve into the impact of the evolving energy spectrum and velocity anisotropic distribution of FEBs on ECMI during their propagation in flare loops. Our findings indicate that if we solely consider the progressively flattened lower energy cutoff behavior as FEBs descend along flare loops, the growth rates of ECMI decrease accordingly. However, when accounting for the evolution of ambient magnetic plasma parameters, the growth rates of ECMI increase as FEBs delve into denser atmosphere. This underscores the significant influence of the energy spectrum and velocity anisotropy distribution evolution of FEBs on ECMI. Our study sheds light on a more comprehensive understanding of the dynamic spectra of solar radio emissions.

We report the timing analysis of PSR J1846−0513, a pulsar discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. The pulsar possesses a spin period of 23.36 ms and a spin-down rate ( $\dot{P}$ ) of 1.0106(3) × 10 ^−18 s s ^−1 , and it is located in an eccentric orbit ( e ∼0.208) with an orbital period of 0.61 days. The characteristic age and surface magnetic field of the pulsar are found to be 366.62 Myr and 4.9178 × 10 ^9 G, respectively, indicating that it is a recycled pulsar. Using over two years of timing data, we measure the periastron advance $\dot{\omega }$ = 0.8956(8) deg yr ^−1 . By assuming that this effect is purely relativistic, we have estimated the total mass M = 2.6287(35) M _⊙ and obtained an upper limit for the pulsar mass and a lower limit for the companion’s mass. Our results indicate that this is a double neutron star system.

The Parkes 20 cm multibeam pulsar surveys have discovered nearly half of the known pulsars and revealed many distant pulsars with high dispersion measures. Using a sample of 1301 pulsars from these surveys, we have explored the spatial distribution and birth rate of normal pulsars. The pulsar distances used to calculate the pulsar surface density are estimated from the YMW16 electron-density model. When estimating the impact of the Galactic background radiation on our survey, we projected pulsars in the galaxy onto the Galactic plane, assuming that the flux density distribution of pulsars is uniform in all directions, and utilized the most up-to-date background temperature map. We also used an up-to-date version of the ATNF Pulsar Catalogue to model the distribution of pulsar flux densities at 1400 MHz. We derive an improved radial distribution for the pulsar surface density projected onto the Galactic plane, which has a maximum value at ∼4 kpc from the Galactic center. We also derive the local surface density and birth rate of pulsars, obtaining 47 ± 5 kpc ^−2 and ∼4.7 ± 0.5 kpc ^−2 Myr ^−1 , respectively. For the total number of potentially detectable pulsars in the galaxy, we obtain (1.1 ± 0.2) × 10 ^4 and (1.1 ± 0.2)×10 ^5 before and after applying the Tauris & Manchester beaming correction model. The radial distribution function is used to estimate the proportion of pulsars in each spiral arm and the Galactic center.

We present phase-connected timing ephemerides, polarization pulse profiles, and Faraday rotation measurements of 12 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in the Commensal Radio Astronomy FAST Survey. The observational data for each pulsar span at least 1 yr. Among them, PSR J1840+2843 shows subpulse drifting, and five pulsars are detected to exhibit pulse nulling phenomena. PSR J0640−0139 and PSR J2031−1254 are isolated millisecond pulsars (MSPs) with stable spin-down rates ( $\dot{P}$ ) of 4.8981(6) × 10 ^−20 s s ^−1 and 6.01(2) × 10 ^−21 s s ^−1 , respectively. Additionally, one pulsar (PSR J1602−0611) is in a neutron star−white dwarf (WD) binary system with an 18.23-day orbit and a companion of ≤0.65 M _⊙ . PSR J1602−0611 has a spin period, companion mass, and orbital eccentricity that are consistent with the theoretical expectations for MSP−helium WD (He WD) systems. Therefore, we believe that it might be an MSP−He WD binary system. The locations of PSR J1751−0542 and PSR J1840+2843 on the $P-\dot{P}$ diagram are beyond the traditional death line. This indicates that FAST has discovered some low- $\dot{E}$ pulsars, contributing new samples for testing pulsar radiation theories. We estimated the distances of these 12 pulsars based on NE2001 and YMW16 electron density models, and our work enhances the data set for investigating the electron density model of the Galaxy.

Understanding the jitter noise resulting from single-pulse phase and shape variations is important for the detection of gravitational waves using pulsar timing arrays. We present measurements of the jitter noise and single-pulse variability of 12 millisecond pulsars that are part of the International Pulsar Timing Array sample using the Five-hundred-meter Aperture Spherical radio Telescope. We find that the levels of jitter noise can vary dramatically among pulsars. A moderate correlation with a correlation coefficient of 0.57 between jitter noise and pulse width is detected. To mitigate jitter noise, we perform matrix template matching using all four Stokes parameters. Our results reveal a reduction in jitter noise ranging from 6.7% to 39.6%. By performing longitude-resolved fluctuation spectrum analysis, we identify periodic intensity modulations in 10 pulsars. In PSR J0030+0451, we detect single pulses with energies more than 10 times the average pulse energy, suggesting the presence of giant pulses. We also observe a periodic mode-changing phenomenon in PSR J0030+0451. We examine the achievable timing precision by selecting a subset of pulses with a specific range of peak intensity, but no significant improvement in timing precision is achievable.

PSR J2150+3427 is a 0.654 s pulsar discovered by the Commensal Radio Astronomy FAST Survey. From the follow-up observations, we find that the pulsar is in a highly eccentric orbit ( e = 0.601) with an orbital period of 10.592 days and a projected semimajor axis of 25.488 lt-s. Using 2.7 yr of timing data, we also measured the rate of periastron advance $\dot{\omega }$ = 0.0115(4) deg yr ^−1 . An estimate for the total mass of the system using the $\dot{\omega }$ gives M _tot = 2.59(13) M _⊙ , which is consistent with most of the known double neutron star (DNS) systems and one neutron star (NS)–white dwarf (WD) system named B2303+46. Combining $\dot{\omega }$ with the mass function of the system gives the masses of M _p < 1.67 and M _c > 0.98 M _⊙ for the pulsar and the companion star, respectively. This constraint, along with the spin period and orbital parameters, suggests that it is possibly a DNS system, and we cannot entirely rule out the possibility of an NS–WD system. Future timing observations will vastly improve the uncertainty in $\dot{\omega }$ , and are likely to allow the detection of additional relativistic effects, which can be used to modify the values of M _p and M _c . With a spin-down luminosity of $\dot{E}$ = 5.07(6) × 10 ^29 erg s ^−1 , PSR J2150+3427 is a very low-luminosity pulsar, with only the binary pulsar J2208+4610 having a smaller $\dot{E}$ .

The existing uniaxial compression test results of salt rock under different loading rates are used to study its energy evolution characteristics during deformation and failure in this study. First of all, the influence of loading rate on the total energy density, elastic energy density, and dissipated energy density is analyzed. Afterward, the relationship between the number and size of fragments, crushing intensity after rock destruction, and energy density of each part is discussed. The results show that the energy evolution process of salt rock during deformation and failure contains three stages, namely, energy accumulation stage, energy dissipation stage, and energy release stage. With the increase in loading rate, the total energy density and dissipated energy density gradually decrease, whereas the elastic energy density increases. When the volume of rock remains constant, the greater the dissipated strain energy, the more the number of fragments will be produced after rock failure. When the dissipated strain energy remains unchanged, the larger the dissipated strain energy (surface free energy) is, the smaller the number and the larger the size of fragments will be produced. When the total strain energy is constant, the splash rate of the fragments increases with increasing elastic strain energy ratio.

The transfer section between the cross passage and the main tunnel is the part that needs to be paid attention to during the underground excavation construction of the subway. Due to complex stress, the collapse of the horsehead gate and excessive surface settlement often occur. In order to determine the construction scheme of the transfer section between the cross passage and the main tunnel of Guanshui Road Station of Metro Line two in Guiyang, China, the numerical simulation method was used to analyze the “double-holes interval pillar method,” “sector expansion method,” and “gate climbing method,”, respectively. The mechanical response of the surrounding rock and supporting structure under each method was compared. The comparisons showed that the surface settlement, the displacement of the cave, and the plastic zone caused by the double-holes interval pillar method were the smallest, and the method can reduce the construction risk, shorten the construction period, and reduce the project cost. Therefore, it was recommended to use the double-holes interval pillar method to construct the transfer section. The comparison between the measured data and the numerical simulation results of the double-holes interval pillar method showed that the numerical simulation results were smaller than the measured data at each point, and the surface settlement and horizontal displacement in the tunnel both met the safety control standard.

We present the discovery and timing results of four pulsars discovered in a pilot survey at intermediate Galactic latitudes with the Five-hundred Aperture Spherical Telescope (FAST). Among these pulsars, two belong to the category of millisecond pulsars (MSPs) with spin periods of less than 20 ms. The other two fall under the classification of “mildly recycled” pulsars, with massive white dwarfs as companions. Remarkably, this small survey, covering an area of 4.7 deg ^2 , led to the discovery of four recycled pulsars. Such success underscores the immense potential of future surveys at intermediate Galactic latitudes. In order to assess the potential yield of MSPs, we conducted population simulations and found that both FAST and Parkes new phased array feed surveys, focusing on intermediate Galactic latitudes, have the capacity to uncover several hundred new MSPs.

Black widows are millisecond pulsars ablating their companions. The material blown from the companion blocks the radio emission, resulting in radio eclipses. The properties of the eclipse medium are poorly understood. Here, we present direct evidence of the existence of magnetic fields in the eclipse medium of the black widow PSR J2051−0827 using observations made with the Five-hundred-meter Aperture Spherical radio Telescope. We detect a regular decrease in rotation measure (RM) in the egress of the eclipse, changing from 60 to −28.7 rad m ^−2 . The RM gradually changes back to normal when the line of sight moves away from the eclipse. The estimated line-of-sight magnetic field strength in the eclipse medium is ∼0.1 G. The RM reversal could be caused by a change in the magnetic field strength along the line of sight due to binary orbital motion. The RM reversal phenomenon has also been observed in some repeating fast radio bursts (FRBs), and the study of spider pulsars may provide additional information about the origin of FRBs.

This paper demonstrates the applicability of the Quantum Walk-based Optimisation Algorithm (QWOA) to the Capacitated Vehicle Routing Problem (CVRP). Efficient algorithms are developed for the indexing and unindexing of the solution space and for implementing the required alternating phase-walk unitaries, which are the core components of QWOA. Results of numerical simulation demonstrate that the QWOA is capable of producing convergence to near-optimal solutions for a randomly generated eight location CVRP. Preparation of the amplified quantum state in this example problem is demonstrated to produce higher-quality solutions than expected from classical random sampling of equivalent computational effort.

This paper proposes a highly efficient quantum algorithm for portfolio optimisation targeted at near-term noisy intermediate-scale quantum computers. Recent work by Hodson et al. (2019) explored potential application of hybrid quantum-classical algorithms to the problem of financial portfolio rebalancing. In particular, they deal with the portfolio optimisation problem using the Quantum Approximate Optimisation Algorithm and the Quantum Alternating Operator Ansatz. In this paper, we demonstrate substantially better performance using a newly developed Quantum Walk Optimisation Algorithm in finding high-quality solutions to the portfolio optimisation problem.

Cytoplasmic viscosity (μc) is a key biomechanical parameter for evaluating the status of cellular cytoskeletons. Previous studies focused on white blood cells, but the data of cytoplasmic viscosity for tumour cells were missing. Tumour cells (H1299, A549 and drug-treated H1299 with compromised cytoskeletons) were aspirated continuously through a micropipette at a pressure of −10 or −5 kPa where aspiration lengths as a function of time were obtained and translated to cytoplasmic viscosity based on a theoretical Newtonian fluid model. Quartile coefficients of dispersion were quantified to evaluate the distributions of cytoplasmic viscosity within the same cell type while neural network-based pattern recognitions were used to classify different cell types based on cytoplasmic viscosity. The single-cell cytoplasmic viscosity with three quartiles and the quartile coefficient of dispersion were quantified as 16.7 Pa s, 42.1 Pa s, 110.3 Pa s and 74% for H1299 cells at −10 kPa (ncell = 652); 144.8 Pa s, 489.8 Pa s, 1390.7 Pa s, and 81% for A549 cells at −10 kPa (ncell = 785); 7.1 Pa s, 13.7 Pa s, 31.5 Pa s, and 63% for CD-treated H1299 cells at −10 kPa (ncell = 651); and 16.9 Pa s, 48.2 Pa s, 150.2 Pa s, and 80% for H1299 cells at −5 kPa (ncell = 600), respectively. Neural network-based pattern recognition produced successful classification rates of 76.7% for H1299 versus A549, 67.0% for H1299 versus drug-treated H1299 and 50.3% for H1299 at −5 and −10 kPa. Variations of cytoplasmic viscosity were observed within the same cell type and among different cell types, suggesting the potential role of cytoplasmic viscosity in cell status evaluation and cell type classification.

In this paper we investigate properties of continuous time chiral quantum walks, which possess complex valued edge weights in the underlying graph structure, together with an initial Gaussian wavefunction spread over a number of vertices. We demonstrate that, for certain graph topology and phase matching conditions, we are able to direct the flow of probability amplitudes in a specific direction inside the graph network. We design a quantum walk graph analogue of an optical circulator which is a combination of a cycle and semi-infinite chain graphs. Excitations input into the circulator from a semi-infinite chain are routed in a directionally biased fashion to output to a different semi-infinite chain. We examine in detail a two port circulator graph which spatially separates excitations flowing back in forth between the two semi-finite chains to directionally occupy the top or bottom half of the cycle portion of the circulator. This setup can be used, for example, to detect non-Markovian processes, which leads to information and energy back-flow from the bath back into the system.

Members of the Brassicaceae family disperse their seeds through a mechanism commonly referred to as fruit dehiscence or pod shatter. Pod shatter is influenced by variations in valve margin structure and by the molecular control pathways related to valve development. Anatomical patterns of the dehiscence zone from Brassica napus L., Brassica rapa L., Brassica carinata L., and Sinapis alba L., representing fruit types differing in pod shatter resistance, were compared using histological staining. The pod shatter-susceptible plant B. napus showed an increased lignin deposition at the vascular bundle of the replum as well as an increased separation of cell layers. In pod shatter-resistant plants S. alba, B. rapa, and B. carinata, we observed two layers of lignified valve margin cells. From these four species, we isolated and identified homologs of SHATTERPROOF (SHP1, SHP2), INDEHISCENT (IND), ALCATRAZ (ALC), FRUITFULL (FUL), AGAMOUS (AG), NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1), and SEEDSTICK (STK) genes involved in fruit development and pod shatter in Arabidopsis. Transcriptional analysis of these eight genes was performed by real-time polymerase chain reaction and the results demonstrate that differences in the expression patterns of the eight genes may be associated with dehiscence variation within these four species.

We present a highly efficient quantum circuit for performing continuous time quantum walks (CTQWs) over an exponentially large set of combinatorial objects, provided that the objects can be indexed efficiently. CTQWs form the core mixing operation of a generalized version of the quantum approximate optimization algorithm, which works by “steering” the quantum amplitude into high-quality solutions. The efficient quantum circuit holds the promise of finding high-quality solutions to certain classes of NP-hard combinatorial problems such as the Travelling Salesman Problem, maximum set splitting, graph partitioning, and lattice path optimization.

A phase field method was used to investigate the influence of charge accumulation at the grain boundary on the electrical behavior of a ferroelectric field-effect transistor containing a polycrystalline gate. Both the domain structure and the electrical behavior of the ferroelectric field-effect transistor were found to depend on the coefficient χ, which represents the charge accumulation at the grain boundary. With increasing χ, both the width of the memory window of the capacitance–voltage curves and the on-state source–drain current decreased, while the off-state source–drain current increased. This can be explained in terms of the weakening polarization effect in the grain interior owing to the presence of a built-in electric field caused by the accumulated charge at the grain boundary.

Circulant matrices are an important family of operators, which have a wide range of applications in science and engineering-related fields. They are, in general, non-sparse and non-unitary. In this paper, we present efficient quantum circuits to implement circulant operators using fewer resources and with lower complexity than existing methods. Moreover, our quantum circuits can be readily extended to the implementation of Toeplitz, Hankel and block circulant matrices. Efficient quantum algorithms to implement the inverses and products of circulant operators are also provided, and an example application in solving the equation of motion for cyclic systems is discussed.

Water transport across the cell membranes is regulated largely by a family of proteins known as aquaporins (AQPs). Plasma membrane intrinsic protein (PIP) is an important subfamily of plant AQPs localized on the plasma membrane. To investigate the molecular mechanism of water regulation in seed germination, seven genes encoding PIP were initially cloned and sequenced from the germinating seed cDNA pool of Brassica napus. They belong to the PIP1 and PIP2 subfamilies. The transcription of the seven cloned genes plus three previously identified AQP genes from B. napus were analyzed in different organs and different stages of seed germination by quantitative real-time PCR (qRT-PCR). The results show that the expressions of the ten AQP genes were lower or scarcely detected in dry seeds, but were up-regulated during germination as well as in young seedlings. In addition, the expression of these ten AQP genes in response to an abiotic stress during seed germination was investigated and the results also show differential responses to abiotic stress treatments. Our findings suggest that these ten genes play different roles during plant development and response to abiotic stresses in B. napus.

Small heat shock proteins (sHSPs) are crucial components of the plant response to heat shock. We identified and analyzed eight sHSP genes of Capsella bursa-pastoris to better understand the ability of this species to adapt. Eight genes were initially cloned and sequenced from the mature embryo cDNA pool. They belong to the cytosolic I (CI), cytosolic II (CII), and cytosolic III (CIII) subfamilies. One CI sHSP gene was homologous to that of C. rubella. Sequence analysis using 3' RACE revealed that there are two or more variable 3'-untranslated regions (UTRs) in these sHSP transcripts. The transcriptional levels of the eight sHSP genes were analyzed in different organs and developmental stages via qRT-PCR. Eight genes were significantly up-regulated in young leaves exposed to heat stress at 42 °C, and also showed differential responses to ABA treatment. We also compared expression of these genes with corresponding Arabidopsis sHSP genes and found some differences between the two species.

Large-scale gene expression analyses were conducted during embryonic development of Capsella bursa-pastoris using the cDNA-AFLP technique, and 231 differentially expressed genes were identified. Most of the transcript-derived fragments (TDFs) were identified against Arabidopsis sequences and a minority against other plant sequences by searching in NCBI database. A total of 128 TDFs, homologous to genes with known functions, were classified into 13 functional categories, and many of them were involved in transcription, metabolism, disease defense and protein binding. Expression profiles of 90 C. bursa-pastoris genes were compared with those of the corresponding Arabidopsis genes and 64 genes showed similar expression profiles and the expression profiles of the rest 26 TDFs were different from those of the relevant Arabidopsis genes. Besides, some genes related to oxidative stress and ABA response were fiercely up-regulated during embryogenesis of C. bursa-pastoris according to RT-PCR.