Germplasm resources are the foundation for improving crop varieties and a strategic asset for global food security. They also advance plant breeding, agricultural biotechnology and the production of essential agricultural goods. To assess the distribution, diversity and conservation status of food crop germplasm in the Hainan Province, China, we conducted a detailed survey of the Hainan Island. Between 2017 and 2022, we collected 330 food crop germplasm resources, encompassing 16 cereal crops, including rice, maize, sweet potato. The collected germplasm resources exhibited traits of high resistance to both biotic and abiotic stresses, including common diseases and drought stress, as well as superior quality and adaptability to poor soil conditions such as sandy land. However, challenges such as low productivity and hybrid degradation were identified. These resources were primarily found in Haikou City, Baisha County, Danzhou City, Wuzhishan City and Sanya City. Additionally, we collected several ancient local varieties and endangered germplasm resources such as ‘Jiezi rice’ and ‘Wuzhishan maize’. This study serves as a reference for the conservation, development and utilization of local food crop germplasm resources in Hainan Province and lays the foundation for breeding and developing new varieties.

Cargo carrying by a spring connected chiral micro-swimmer in a square channel is numerical studied by the three-dimensional lattice Boltzmann method and a chiral squirmer model. The effects of the driving type (β), swimming Reynolds number (Rep), spin coefficient (ξ) and diameter ratio (S) on the changes of the cargo-carrying velocity, spring length and motion modes are investigated, respectively. Four kinds of interesting motion modes are observed. When the chirality is not considered, the optimal combination for maximising swimming velocity are the pusher–cargo and cargo–puller configurations when Rep = 0.1 ∼ 1. When Rep is enhanced, the swimming velocities of the pusher–cargo, puller–cargo and cargo–pusher are increased, while the velocity of the cargo–puller is gradually decreased. When considering the chirality, only the swimming velocity of cargo–pusher and cargo–puller keep an interesting increment, and the reverse motion mode for the pusher-cargo and puller-cargo is firstly found in the present work when ξ exceeds a certain value. The impact of S on the cargo-carrying behaviour is complex, three kinds of oscillatory trajectories will appear under different ξ and S. The swimming velocity is reduced and even zero velocity will be observed when S is large. This work reveals key factors on the movement of microorganisms, offering guidance for improving cargo-carrying capabilities.

Coherent combining of several low-energy few-cycle beams offers a reliable and feasible approach to producing few-cycle laser pulses with energies exceeding the multi-joule level. However, time synchronization and carrier-envelope phase difference (ΔCEP) between pulses significantly affect the temporal waveform and intensity of the combined pulse, requiring precise measurement and control. Here, we propose a concise optical method based on the phase retrieval of spectral interference and quadratic function symmetry axis fitting to simultaneously measure the time synchronization and ΔCEP between few-cycle pulses. The control precision of our coherent beam combining system can achieve a time delay stability within 42 as and ΔCEP measurement precision of 40 mrad, enabling a maximum combining efficiency of 98.5%. This method can effectively improve the performance and stability of coherent beam combining systems for few-cycle lasers, which will facilitate the obtaining of high-quality few-cycle lasers with high energy.

High-power laser systems require thin films with extremely low absorption. Ultra-low-absorption films are often fabricated via ion beam sputtering, which is costly and slow. This study analyzes the impact of doping titanium and annealing on the absorption characteristics of thin films, focusing on composition and structure. The results indicate that the primary factor influencing absorption is composition. Suppressing the presence of electrons or holes that do not form stable chemical bonds can significantly reduce absorption; for amorphous thin films, the structural influence on absorption is relatively minor. Thus, composition control is crucial for fabricating ultra-low-absorption films, while the deposition method is secondary. Ion beam-assisted electron-beam evaporation, which is relatively seldom used for fabricating low-absorption films, was employed to produce high-reflectivity films. After annealing, the absorption at 1064 nm reached 1.70 parts per million. This method offers a cost-effective and rapid approach for fabricating ultra-low-absorption films.

The demand for separating and analysing rare target cells is increasing dramatically for vital applications such as cancer treatment and cell-based therapies. However, there remains a grand challenge for high-throughput and label-free segregation of lesion cells with similar sizes. Cancer cells with different invasiveness usually manifest distinct deformability. In this work, we employ a hydrogel microparticle system with similar sizes but varied stiffness to mimic cancer cells and examine in situ their deformation and focusing under microfluidic flow. We first demonstrate the similar focusing behaviour of hydrogel microparticles and cancer cells in confined flow that is dominated by deformability-induced lateral migration. The deformation, orientation and focusing position of hydrogel microparticles in microfluidic flow under different Reynolds numbers are then systematically observed and measured using a high-speed camera. Linear correlations of the Taylor deformation and tilt angle of hydrogel microparticles with the capillary number are revealed, consistent with theoretical predictions. Detailed analysis of the dependence of particle focusing on the flow rate and particle stiffness enables us to identify a linear scaling between the equilibrium focusing position and the major axis of the deformed microparticles, which is uniquely determined by the capillary number. Our findings provide insights into the focusing and dynamics of soft beads, such as cells and hydrogel microparticles, under confined flow, and pave the way for applications including the separation and identification of circulating tumour cells, drug delivery and controlled drug release.

The Early-Middle Jurassic impression/compression macroflora and the palynoflora from the Qaidam Basin in the northeastern Qinghai-Xizang (Tibetan) Plateau have been well studied; however, fossil wood from this region has not been previously documented systematically. Here, we describe an anatomically well-preserved fossil wood specimen from the Lower Jurassic Huoshaoshan Formation at the Dameigou section in northern Qinghai Province, northwestern China. This fossil exhibits typical Metapodocarpoxylon Dupéron-Laudoueneix et Pons anatomy with usually araucarian radial tracheid pits and variable cross-field pits, representing a new record for Metapodocarpoxylon in the Qaidam Basin. This discovery indicates that trees with this type of wood anatomy were not confined to northern Gondwana but also grew in more northerly regions in Laurasia. The wood displays distinct growth rings, with abundant, well-formed earlywood and narrow latewood. This observation, along with previous interpretations based on macroflora, palynoflora and sedimentological data, suggests that a warm and humid climate with mild seasonality prevailed in the region during the Early Jurassic.

Laser-driven inertial confinement fusion (ICF) diagnostics play a crucial role in understanding the complex physical processes governing ICF and enabling ignition. During the ICF process, the interaction between the high-power laser and ablation material leads to the formation of a plasma critical surface, which reflects a significant portion of the driving laser, reducing the efficiency of laser energy conversion into implosive kinetic energy. Effective diagnostic methods for the critical surface remain elusive. In this work, we propose a novel optical diagnostic approach to investigate the plasma critical surface. This method has been experimentally validated, providing new insights into the critical surface morphology and dynamics. This advancement represents a significant step forward in ICF diagnostic capabilities, with the potential to inform strategies for enhancing the uniformity of the driving laser and target surface, ultimately improving the efficiency of converting laser energy into implosion kinetic energy and enabling ignition.

The multi-colour complete light curves and low-resolution spectra of two short period eclipsing Am binaries V404 Aur and GW Gem are presented. The stellar atmospheric parameters of the primary stars were derived through the spectra fitting. The observed and TESS-based light curves of them were analysed by using the Wilson-Devinney code. The photometric solutions suggest that both V404 Aur and GW Gem are semi-detached systems with the secondary component filling its critical Roche Lobe, while the former should be a marginal contact binary. The $O-C$ analysis found that the period of V404 Aur is decreasing at a rate of $dP/dt=-1.06(\pm0.01)\times 10^{-7}\,\mathrm{d}\,\mathrm{ yr}^{-1}$, while the period of GW Gem is increasing at $dP/dt=+2.41(\pm0.01)\times 10^{-8} \mathrm{d}\,\mathrm{yr}^{-1}$. The period decrease of V404 Aur may mainly be caused by the combined effects of the angular momentum loss (AML) via an enhanced stellar wind of the more evolved secondary star and mass transfer between two components. The period increase of GW Gem supports the mass transfer from the secondary to the primary. Both targets may be in the broken contact stage predicted by the thermal relaxation oscillations theory and will eventually evolve to the contact stage. We have collected about 54 well-known eclipsing Am binaries with absolute parameters from the literature. The relations of these parameters are summarised. There are some components that have a higher degree of evolution. The majority of their hydrogen shell may have been stripped away and the stellar internal layer exposed. The accretion processes from such evolved components may be very important for the formation of Am peculiarity in binaries.

During the investigation of parasitic pathogens of Mytilus coruscus, infection of a Perkinsus-like protozoan parasite was detected by alternative Ray's Fluid Thioglycolate Medium (ARFTM). The diameter of hypnospores or prezoosporangia was 8–27 (15.6 ± 4.0, n = 111) μm. The prevalence of the Perkinsus-like species in M. coruscus was 25 and 12.5% using ARFTM and PCR, respectively. The ITS1-5.8S-ITS2 fragments amplified by PCR assay had 100% homology to that of P. beihaiensis, suggesting that the protozoan parasite was P. beihaisensis and M. coruscus was its new host in East China Sea (ECS). Histological analysis showed the presence of trophozoites of P. beihaiensis in gill, mantle and visceral mass, and the schizonts only found in visceral mass. Perkinsus beihaiensis infection led to inflammatory reaction of hemocyte and the destruction of digestive tubules in visceral mass, which had negative effect on health of the farmed M. coruscus and it deserves more attention.

The elasto-inertial focusing and rotating characteristics of spheroids in a square channel flow of Oldroyd-B viscoelastic fluids are studied by the direct forcing/fictitious domain method. The rotational behaviours, changes in the equilibrium positions and travel distances are explored to analyse the mechanisms of spheroid migration in viscoelastic fluids. Within the present simulated parameters (1 ≤ Re ≤ 100, 0 ≤ Wi ≤ 2, 0.4 ≤ α ≤3), the results show that there are four kinds of equilibrium positions and six (five) kinds of rotational behaviours for the elasto-inertial migration of prolate (oblate) spheroids. We are the first to identify a new rotational mode for the migration of prolate spheroids. Only when the particles are initially located at a corner and wall bisector, some special initial orientations of the spheroids have an impact on the final equilibrium position and rotational mode. In other general initial positions, the initial orientation of the spheroid has a negligible effect. A higher Weissenberg number means the faster the particles migrate to the equilibrium position. The spheroid gradually changes from the corner (CO), channel centreline (CC), diagonal line (DL) and cross-section midline (CSM) equilibrium positions as the elastic number decreases, depending on the aspect ratio, initial orientation and rotational behaviour of the particles and the elastic number of the fluid. When the elastic number is less than the critical value, the types of rotational modes of the spheroids are reduced. By controlling the elastic number near the critical value, spheroids with different aspect ratios can be efficiently separated.

We consider the community detection problem in sparse random hypergraphs under the non-uniform hypergraph stochastic block model (HSBM), a general model of random networks with community structure and higher-order interactions. When the random hypergraph has bounded expected degrees, we provide a spectral algorithm that outputs a partition with at least a $\gamma$ fraction of the vertices classified correctly, where $\gamma \in (0.5,1)$ depends on the signal-to-noise ratio (SNR) of the model. When the SNR grows slowly as the number of vertices goes to infinity, our algorithm achieves weak consistency, which improves the previous results in Ghoshdastidar and Dukkipati ((2017) Ann. Stat. 45(1) 289–315.) for non-uniform HSBMs.

Our spectral algorithm consists of three major steps: (1) Hyperedge selection: select hyperedges of certain sizes to provide the maximal signal-to-noise ratio for the induced sub-hypergraph; (2) Spectral partition: construct a regularised adjacency matrix and obtain an approximate partition based on singular vectors; (3) Correction and merging: incorporate the hyperedge information from adjacency tensors to upgrade the error rate guarantee. The theoretical analysis of our algorithm relies on the concentration and regularisation of the adjacency matrix for sparse non-uniform random hypergraphs, which can be of independent interest.

Decentralization is believed to ensure better environmental governance. However, recent studies have shown that some governments recentralize local enforcement to increase the effectiveness of policy implementation. Under what conditions is recentralization the better option for environmental enforcement? This study attempts to differentiate two possible mechanisms through which recentralization can deliver better environmental outcomes: curbing elite capture and enhancing local resources. In the context of recentralization reform and with a unique dataset of local investigations into China's environmental enforcement, we demonstrate that although decentralization has been successful from many perspectives, recentralizing local environmental enforcement can produce better outcomes for pollution reduction in China, by curbing local protectionism rather than enhancing local resources. Further qualitative analysis reveals why recentralization cannot necessarily enhance local resources and capacity, even though it is designed to do so.

The assessment of seed quality and physiological potential is essential in seed production and crop breeding. In the process of rapid detection of seed viability using tetrazolium (TZ) staining, it is necessary to spend a lot of labour and material resources to explore the pretreatment and staining methods of hard and solid seeds with physical barriers. This study explores the TZ staining methods of six hard seeds (Tilia miqueliana, Tilia henryana, Sassafras tzumu, Prunus subhirtella, Prunus sibirica, and Juglans mandshurica) and summarizes the TZ staining conditions required for hard seeds by combining the difference in fat content between seeds and the kinship between species, thus providing a rapid viability test method for the protection of germplasm resources of endangered plants and the optimization of seed bank construction. The TZ staining of six species of hard seeds requires a staining temperature above 35 °C and a TZ solution concentration higher than 1%. Endospermic seeds require shorter staining times than exalbuminous seeds. The higher the fat content of the seeds, the lower the required incubation temperature and TZ concentration for staining, and the longer the staining time. And the closer the relationship between the two species, the more similar their staining conditions become. The TZ staining method of similar species can be predicted according to the genetic distance between the phylogenetic trees, and the viability of new species can be detected quickly.

The construction of organic-inorganic hybrid ferroelectric materials with larger, high-polarity guest molecules intercalated in kaolinite (K) faces difficulties in terms of synthesis and uncertainty of structure-property relationships. The purpose of the present study was to optimize the synthesis method and to determine the mechanism of ferroelectric behavior of kaolinite intercalated with p-aminobenzamide (PABA), with an eye to improving the design of intercalation methods and better utilization of clay-based ferroelectric materials. The K-PABA intercalation compound (chemical formula Al2Si2O5(OH)4∙(PABA)0.7) was synthesized in an autoclave and then characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The experimental results showed that PABA expanded the kaolinite interlayer from 7.2 Å to 14.5 Å, and the orientation of the PABA molecule was ~70° from the plane of the kaolinite layers. The amino group of the PABA molecule was close to the Si sheet. The presence of intermolecular hydrogen bonds between kaolinite and PABA and among PABA molecules caused macro polarization of K-PABA and dipole inversion under the external electric field, resulting in K-PABA ferroelectricity. Simulation calculations using the Cambridge Sequential Total Energy Package (CASTEP) and the ferroelectricity test revealed the optimized intercalation model and possible ferroelectric mechanism.