We study nonlinear resonant triad interactions among flexural-gravity waves generated by a steadily moving load on a floating ice sheet. Of the many possible triad interactions involving at least one load-produced wave, we focus on the double-frequency case where the wavenumber of the leading wave is double that of the trailing wave. This case stands out because resonant interactions can occur with or without the presence of an ambient wave. Using multiple-scale perturbation analysis, we obtain amplitude evolution equations governing the leading-order, steady-state response. We complement the theoretical predictions with direct numerical simulations of the initial–boundary value problem using a high-order spectral method accurate to arbitrary order. Our results show that the double-frequency interaction can cause the trailing wave amplitude to decay with distance from the load, with its energy transferred to its second harmonic which radiates forwards to coherently interfere with the leading wave. Depending on the length and orientation of the load, the resonant interaction can in some cases cause the wave drag to become vanishingly small, or in other cases nearly double the maximum bending strain compared to the linear prediction. We also consider the effect of a small ambient wave that can initiate a resonant interaction in the leading wave field in addition to the trailing wave field interaction. This can result in a steady, localised wave packet containing two mutually trapped wave components, leading to vanishing wave drag. This work has potential implications for defining safe operating profiles for vehicles travelling on floating ice.

A recent study published in Oryx proposed that the extinct Javan tiger Panthera tigris sondaica may still survive on the Island of Java, Indonesia, based on mitochondrial DNA analysis of a single hair sample collected from a location where a tiger was reportedly encountered. However, upon reanalysing the genetic data presented in that study, we conclude that there is little support for this claim. The sequences of the putative tiger hair and Javan tiger museum specimens generated are not from tiger cytoplasmic mitochondrial DNA but more likely the nuclear pseudogene copies of mitochondrial DNA. In addition, the number of mismatches between the two Javan tiger sequences is unusually high for homologous sequences that are both from tigers, suggesting potential issues with data reliability. The paper provides insufficient details on quality control measures, making it impossible to rule out the possibility that errors were introduced during the analysis. Consequently, it is inappropriate to use the sequences presented in that study to infer the existence of the Javan tiger.

This study aimed to explore the potential causal association between PUFA and the risk of intrahepatic cholestasis of pregnancy (ICP) using Mendelian randomisation (MR) analysis. A two-sample MR analysis was conducted utilising large-scale European-based genome-wide association studies summary databases. The primary MR analysis was carried out using the inverse variance-weighted (IVW) method, complemented by other methods such as MR-egger, weighted-median and weighted mode. Sensitivity analysis was also performed to validate the robustness of the findings. Results indicated a 31 % reduced risk of ICP for every 1 standard deviation (sd) increase in n-3 fatty acids levels (OR = 0·69, 95 % CI: 0·54, 0·89, P = 0·004) and in the ratio of n-3 fatty acids to total fatty acids (OR = 0·69, 95 % CI: 0·53, 0·91, P = 0·008). Conversely, there was a 51 % increased risk of ICP for every 1 sd increase in the ratio of n-6 fatty acids to n-3 fatty acids (OR = 1·51, 95 % CI: 1·20, 1·91, P < 0·001) and a 138 % increased risk for every 1 sd increase in the ratio of linoleic fatty acids to total fatty acids (OR = 2·38, 95 % CI: 1·55, 3·66, P < 0·001). The findings suggest that n-3 fatty acids may have a protective effect against the risk of ICP, while n-6 fatty acids and linoleic fatty acids could be potential risk factors for ICP. The supplementation of n-3 fatty acids, as opposed to n-6 fatty acids, could be a promising strategy for the prevention and management of ICP.

Three-dimensional effects of sidewalls on the low-frequency unsteadiness of the shock-wave/boundary-layer interaction (SBLI) are of academic and practical importance but not yet well understood. Considerable attention has been paid to the viscous effect of sidewalls, whereas the potential inviscid confinement effect of sidewalls has received little attention. The present work provides experimental evidence of multiscale spanwise travelling waves crossing the separation front under the confinement of sidewalls. Global pressure measurements were made for a sidewall-confined 24$^\circ$ compression ramp interaction in Mach-2.83 flow using fast-responding pressure-sensitive paint. The unsteady pressure in a statistically two-dimensional intermittent region suggests that in addition to the canonical streamwise oscillation, the separation front exhibits significant low-frequency, multiscale spanwise distortion. Modal analysis further reveals that multiscale spanwise unsteadiness has higher intensity and frequency than the streamwise oscillation. Such strong spanwise unsteadiness calls attention to the low-frequency unsteadiness in previous sidewall-confined SBLI experiments and encourages further study on the mechanism of the confinement effect.

This paper retrospectively analysed the prevalence of macrolide-resistant Mycoplasma pneumoniae (MRMP) in some parts of China. Between January 2013 and December 2019, we collected 4,145 respiratory samples, including pharyngeal swabs and alveolar lavage fluid. The highest PCR-positive rate of M. pneumoniae was 74.5% in Beijing, the highest resistance rate was 100% in Shanghai, and Gansu was the lowest with 20%. The highest PCR-positive rate of M. pneumoniae was 74.5% in 2013, and the highest MRMP was 97.4% in 2019; the PCR-positive rate of M. pneumoniae for adults in Beijing was 17.9% and the MRMP was 10.48%. Among the children diagnosed with community-acquired pneumonia (CAP), the PCR-positive and macrolide-resistant rates of M. pneumoniae were both higher in the severe ones. A2063G in domain V of 23S rRNA was the major macrolide-resistant mutation, accounting for more than 90%. The MIC values of all MRMP to erythromycin and azithromycin were ≥ 64 μg/ml, and the MICs of tetracycline and levofloxacin were ≤ 0.5 μg/ml and ≤ 1 μg/ml, respectively. The macrolide resistance varied in different regions and years. Among inpatients, the macrolide-resistant rate was higher in severe pneumonia. A2063G was the common mutation, and we found no resistance to tetracycline and levofloxacin.

This article focuses on how the policy on same-sex marriage and a person’s social locations impact upon Chinese lesbians’ life chances and welfare. Bringing the familisation and defamilisation literature, which has predominantly focused on heterosexual populations and families, into dialogue with an intersectionality perspective, we map the ways in which gender, sexuality, and class intersect in shaping lesbians’ experiences of defamilisation and familisation risks. The findings, drawn from interviews conducted in Beijing, China, reveal that the absence of legalised same-sex marriage, coupled with a lack of familial and societal recognition of same-sex relationships, exposes lesbians to both defamilisation and familisation risks, leading to difficulties in choosing whether and how to participate in the family. The intersectionality lens guides us to move beyond the heterosexual/homosexual boundary and to rethink the possibility of welfare alliances that can improve the welfare of not only lesbians but also other groups of women and minorities.

We study nonlinear resonant wave–wave interactions which occur when ocean waves propagate into a thin floating ice sheet. Using multiple-scale perturbation analysis, we obtain theoretical predictions of the wave amplitude evolution as a function of distance travelled past the ice edge for a semi-infinite ice sheet. The theoretical predictions are supported by a high-order spectral (HOS) method capable of simulating nonlinear interactions in both open water and the ice sheet. Using the HOS method, the amplitude evolution predictions are extended to multiple (coupled) triad interactions and a single ice sheet of finite length. We relate the amplitude evolution to mechanisms with strong frequency dependence – ice bending strain, related to ice breakup, as well as wave reflection and transmission. We show that, due to sum-frequency interactions, the maximum strain in the ice sheet can be more than twice that predicted by linearised theory. For an ice sheet of finite length, we show that nonlinear wave reflection and transmission coefficients depend on a parameter in terms of wave steepness and ice length, and can have values significantly different than those from linear theory. In particular, we show that nonlinear sum-frequency interactions can appreciably decrease the total wave energy transmitted past the ice sheet. This work has implications for understanding the occurrence of ice breakup, wave attenuation due to scattering in the marginal ice zone and the resulting ice floe size distribution.

In preparation for an experiment with a laser-generated intense proton beam at the Laser Fusion Research Center at Mianyang to investigate the 11B(p,α)2α reaction, we performed a measurement at very low proton energy between 140 keV and 172 keV using the high-voltage platform at the Institute of Modern Physics, Lanzhou. The aim of the experiment was to test the ability to use CR-39 track detectors for cross-section measurements and to remeasure the cross-section of this reaction close to the first resonance using the thick target approach. We obtained the cross-section σ = 45.6 ± 12.5 mb near 156 keV. Our result confirms the feasibility of CR-39 type track detector for nuclear reaction measurement also in low-energy regions.

Effects of solid nanolayers embedded in a near-critical density plasma on the laser-driven collisionless shock acceleration are investigated by using two-dimensional particle-in-cell simulations. Due to the interaction of nanolayers and the incident laser, an additional number of hot electrons are generated and an inhomogeneous magnetic field is induced. As a result, the collisionless shock is reinforced within the nanolayer gaps compared to the target without the structured nanolayers. When the laser intensity is 9.8 × 1019 W/cm2, the amplitude of the electrostatic field is increased by 30% and the shock velocity is increased from 0.079c to 0.091c, leading to an enhancement of the peak energy and the cutoff energy of accelerated protons, from 6.9 MeV to 9.1 MeV and 12.2 MeV to 20.0 MeV, respectively. Furthermore, the effects of the width of the nanolayer gaps are studied, by adjusting the gap width of nanolayers, and optimal nanolayer setups for collisionless shock acceleration can be acquired.

Modified kaolinites possess excellent adsorption properties and, therefore, are regarded widely as potential catalytic components. The use of modified kaolinites as a catalytic component for Fischer–Tropsch synthesis (FTS) has remained unexplored, however. In the current study, delaminated and pit-rich nano-kaolinite was prepared via acid treatment of N-methylformamide (NMF)-intercalated kaolinite (intercalation-etching strategy), and was used as a support to prepare a cobalt-based FTS catalyst (denoted as 15%-Co-HNKln). Compared with other FTS catalysts, the supports for which were raw kaolinite or directly acid-treated kaolinite, the 15%-Co-HNKln showed several advantages such as large specific surface area, dispersed Co particles with small particle size, more new active sites, and significant surface acidity. Given the aforementioned advantages, the 15%-Co-HNKln catalyst demonstrated very good FTS performance. Compared with that of the raw kaolinite-supported FTS catalyst, the CO conversion rate and C5–C12 hydrocarbon selectivity of 15%-Co-HNKln increased by 20% and 15%, respectively.

The effects of magnetic vortex acceleration (MVA) are investigated with two-dimensional particle-in-cell (PIC) simulations by laser interaction with near-critical density (NCD) plasma inside a hollow conical plasma. Energetic and collimated proton beams can be accelerated by a longitudinal charge-separation field. Energetic protons with a peak energy of 220 MeV are produced in PIC simulations. Compared with a uniform NCD plasma, both the cutoff energy and collimation of proton beams are improved remarkably. Furthermore, the influence of different gap sizes of cone tip is taken into account. For optimizing magnetic vortex acceleration, the gap size of the cone tip is suggested to match the focal spot size of laser pulse.

A local COVID-19 outbreak with two community clusters occurred in a large industrial city, Shaoxing, China, in December 2021 after serial interventions were imposed. We aimed to understand the reason by analysing the characteristics of the outbreak and evaluating the effects of phase-adjusted interventions. Publicly available data from 7 December 2021 to 25 January 2022 were collected to analyse the epidemiological characteristics of this outbreak. The incubation period was estimated using Hamiltonian Monte Carlo method. A well-fitted extended susceptible-exposed-infectious-recovered model was used to simulate the impact of different interventions under various combination of scenarios. There were 387 SARS-CoV-2-infected cases identified, and 8.3% of them were initially diagnosed as asymptomatic cases. The estimated incubation period was 5.4 (95% CI 5.2–5.7) days for all patients. Strengthened measures of comprehensive quarantine based on tracing led to less infections and a shorter duration of epidemic. With a same period of incubation, comprehensive quarantine was more effective in containing the transmission than other interventions. Our findings reveal an important role of tracing and comprehensive quarantine in blocking community spread when a cluster occurred. Regions with tense resources can adopt home quarantine as a relatively affordable and low-impact intervention measure compared with centralized quarantine.

This explanatory mixed-method study seeks to understand the relationships between second language (L2) motivation (including the ideal L2 self and the ought-to L2 self) and students’ informal digital learning of English (IDLE) and whether such relationships are mediated by the most prominent positive emotion – enjoyment. A total of 391 Chinese university students participated in the survey, and 15 of them were interviewed later. Quantitative analysis revealed a strong positive relationship between the ideal L2 self and participants’ IDLE, which was partially mediated by foreign language enjoyment (FLE), while the hypotheses that the ought-to L2 self significantly predicted FLE and IDLE were rejected. The qualitative data added details to how a vivid and elaborate L2 vision contributed to enhanced English learning enjoyment and served as the most influential motivator for IDLE practices. Meanwhile, the external and instrumental motives could not predict Chinese university students’ enjoyment, disempowering them to invest in productive language learning practices in the informal and digitalized environment. The discussion of these findings and pedagogical implications helps to chart the path for utilizing the power of the ideal L2 self to engage Chinese university students with the extramural and digitalized language learning ecology.

This paper presents the first systematic study of the political behaviour of female members of China's national legislature, the National People's Congress (NPC). Women held 23 per cent of seats in the 12th NPC, yet they sponsored 44 per cent of all legislative bill proposals and more than half of the bills relevant to women's interests. Women sponsored more bills (4.8 bills) than did men (3.1 bills). We propose that there are two mechanisms driving women's outperformance: (i) women are more collaborative than men, and (ii) female leadership encourages female participation. We analyse 2,366 bills and show that women are disproportionately more active than men in all issue areas and are particularly engaged with women's issues. Our findings demonstrate that underrepresented regime outsiders (women) can carve out a space to amplify their voices, outperform insiders and shape policy direction to a certain extent within an authoritarian legislature.

Rodents and shrews are major reservoirs of various pathogens that are related to zoonotic infectious diseases. The purpose of this study was to investigate co-infections of zoonotic pathogens in rodents and shrews trapped in four provinces of China. We sampled different rodent and shrew communities within and around human settlements in four provinces of China and characterised several important zoonotic viral, bacterial, and parasitic pathogens by PCR methods and phylogenetic analysis. A total of 864 rodents and shrews belonging to 24 and 13 species from RODENTIA and EULIPOTYPHLA orders were captured, respectively. For viral pathogens, two species of hantavirus (Hantaan orthohantavirus and Caobang orthohantavirus) were identified in 3.47% of rodents and shrews. The overall prevalence of Bartonella spp., Anaplasmataceae, Babesia spp., Leptospira spp., Spotted fever group Rickettsiae, Borrelia spp., and Coxiella burnetii were 31.25%, 8.91%, 4.17%, 3.94%, 3.59%, 3.47%, and 0.58%, respectively. Furthermore, the highest co-infection status of three pathogens was observed among Bartonella spp., Leptospira spp., and Anaplasmataceae with a co-infection rate of 0.46%. Our results suggested that species distribution and co-infections of zoonotic pathogens were prevalent in rodents and shrews, highlighting the necessity of active surveillance for zoonotic pathogens in wild mammals in wider regions.

The use of molecular markers is one of the most sensitive, powerful technologies for genetic purity assessment of seed lots. In this study, we aimed to develop a set of insertion and deletion (InDel) markers, through bioinformatics approaches, that may effectively distinguish three representative japonica rice (Oryza sativa L.) varieties, Nipponbare, Taichung 65 and Zhonghua11. The published whole-genome sequences of these varieties were aligned using BWA-MEM, followed by manual inspection for InDels of more than ten base pairs in size with the tview function of SAMtools. A set of ten InDel markers were thus identified and then validated by PCR in the three japonica rice varieties and their intercross F1 hybrids. Results showed that the InDel markers developed in this study could reliably distinguish these three japonica rice varieties. These molecular markers together with the detection method developed here can be applied to DNA-based genetic purity evaluation in rice breeding.

A novel curved surface nanowire target is proposed to improve the cutoff energy of accelerated protons via target normal sheath acceleration. The interaction of a laser of intensity $1.37\times 10^{20}\ {\rm W}\ {\rm cm}^{-2}$ with a curved surface nanowire target is studied by two-dimensional particle-in-cell simulations. The numerical results indicate that the sheath electric field at the target rear side is significantly enhanced by this simple target design, compared with using the planar nanowire target. The transverse motion of hot electrons is effectively confined and the energy density of electrons is naturally increased. A series of simulations with various target parameters is carried out to investigate the performance of this novel target. This tailored target may provide implications for generating high-quality proton beams in experiments.

The Yellow River originates on the Tibetan Plateau and transports vast amounts of terrestrial sediment to the ocean. However, previous studies have not reached a consensus as to when and how the Yellow River first began to flow into the sea. Here we present Sr-Nd-Pb isotope data and a high-resolution clay mineral record of a 200-m-long sediment core recovered from the modern Yellow River delta. The changes in Sr-Nd-Pb isotopic compositions and clay minerals at 0.71 Ma suggest that a larger proportion of sediment was derived from the Yellow River after this time. We propose that the Yellow River has influenced the Bohai Sea since 1.9 Ma (or even earlier), which provides important evidence for an older Yellow River than 1.2 Ma. A significant increase in discharge of Yellow River sediments since 0.71 Ma is due to continuing subsidence of the eastern China coast, the large amplitude of Quaternary sea-level changes, and increased supply of eroded loess during the last 1.0 Ma. After this time, the contribution of local rivers surrounding the Bohai Sea became negligible due to dilution by the huge amounts of Yellow River sediments. These results provide improved constraints on the evolution of the Yellow River and subsequent land-sea fluxes.

Recently, Scholten and Read (2014) found new violations of dominance in intertemporal choice. Although adding a small receipt before a delayed payment or adding a small delayed receipt after an immediate receipt makes the prospect objectively better, it decreases the preference for that prospect (better is worse). Conversely, although adding a small payment before a delayed receipt or adding a small delayed payment after an immediate payment makes the prospect objectively worse, it increases the preference for that prospect (worse is better). Scholten and Read explained these violations in terms of a preference for improvement. However, to produce violations such as these, we find that the temporal sequences need not be constructed as Scholten and Read suggested. In this study, adding a small receipt before a dated receipt (thus constructed as improving) or adding a receipt after a dated payment (thus constructed as improving) decreases preferences for those prospects. Conversely, adding a small payment after a dated receipt (thus constructed as deteriorating) or adding a small payment before a delayed payment (thus constructed as deteriorating) increases preferences for those prospects.

The influence of second-order dispersion (SOD) on stimulated Raman scattering (SRS) in the interaction of an ultrashort intense laser with plasma was investigated. More significant backward SRS was observed with the increase of the absolute value of SOD ($\mid \kern-1pt\!{\psi}_2\!\kern-1pt\mid$). The integrated intensity of the scattered light is positively correlated to the driver laser pulse duration. Accompanied by the side SRS, filaments with different angles along the laser propagation direction were observed in the transverse shadowgraph. A model incorporating Landau damping and above-threshold ionization was developed to explain the SOD-dependent angular distribution of the filaments.