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In this study, the propagation behaviour of detonation waves in a channel filled with stratified media is analysed using a detailed chemical reaction model. Two symmetrical layers of non-reactive gas are introduced near the upper and lower walls to encapsulate a stoichiometric premixed H2–air mixture. The effects of gas temperature and molecular weight of the non-reactive layers on the detonation wave’s propagation mode and velocity are examined thoroughly. The results reveal that as the non-reactive gas temperature increases, the detonation wave front transitions from a ‘convex’ to a ‘concave’ shape, accompanied by an increase in wave velocity. Notably, the concave wave front comprises detached shocks, oblique shocks and detonation waves, with the overall wave system propagating at a velocity exceeding the theoretical Chapman–Jouguet speed, indicating the emergence of a strong detonation wave. Furthermore, when the molecular weight of non-reactive layers varies, the results qualitatively align with those obtained from temperature variations. To elucidate the formation mechanism of different detonation wave front shapes, a dimensionless parameter $\eta$ (defined as a function of the specific heat ratio and sound speed) is proposed. This parameter unifies the effects of temperature and molecular weight, confirming that the specific heat ratio and sound speed of non-reactive layers are the primary factors governing the detonation wave propagation mode. Additionally, considering the effect of mixture inhomogeneity on the detonation reaction zone, the stream tube contraction theory is proposed, successfully explaining why strong detonation waves form in stratified mixtures. Numerical results show good agreement with theoretical predictions, validating the proposed model.
Supporting family caregivers (FCs) is a critical core function of palliative care. Brief, reliable tools suitable for busy clinical work in Taiwan are needed to assess bereavement risk factors accurately. The aim is to develop and evaluate a brief bereavement scale completed by FCs and applicable to medical staff.
Methods
This study adopted convenience sampling. Participants were approached through an intentional sampling of patients’ FCs at 1 palliative care center in Taiwan. This cross-sectional study referred to 4 theories to generate the initial version of the Hospice Foundation of Taiwan Bereavement Assessment Scale (HFT-BAS). A 9-item questionnaire was initially developed by 12 palliative care experts through Delphi and verified by content validity. A combination of exploratory factor analysis (EFA), reliability measures including items analysis, Cronbach’s alpha and inter-subscale correlations, and confirmatory factor analysis (CFA) was employed to test its psychometric properties.
Results
Two hundred seventy-eight participants conducted the questionnaire. Three dimensions were subsequently extracted by EFA: “Intimate relationship,” “Existential meaning,” and “Disorganization.” The Cronbach’s alpha of the HFT-BAS scale was 0.70, while the 3 dimensions were all significantly correlated with total scores. CFA was the measurement model: chi-squared/degrees of freedom ratio = 1.9, Goodness of Fit Index = 0.93, Comparative Fit Index = 0.92, root mean square error of approximation = 0.08. CFA confirmed the scale’s construct validity with a good model fit.
Significance of results
This study developed an HFT-BAS and assessed its psychometric properties. The scale can evaluate the bereavement risk factors of FCs in clinical palliative care.
We present 35 AMS 14C dates from 26 horizons on a 30-cm gravity core from Shira Lake in the republic of Khakassia, Central Russia. The chronology of the core is determined by 210Pb/137Cs dating results and interpretation of elemental geochemistry with historic documents, covering deposition since ca. 1870 CE. This study assesses the old carbon influence (OCI) on organic carbon 14C by comparison with the 210Pb/137Cs dates, sources of carbon, and lake conditions interpreted from elemental proxies. These include elemental concentrations in 0.5N HCl leaches and Aqua Regia dissolution fractions, as well as organic C, N and C/N measurements. From these data we establish a succession of the following six zones: I) (1870∼1900 CE) relatively fresh lake with high lake level, low productivity and high surface runoff (wet conditions); II) (1900∼1940 CE) a “white zone” reflected by high carbonate and low magnetic signal formed in a saline, oxidizing and holomictic lake stage; III) (1940∼1963 CE) reduced carbonate with elevated organic C, N, C/N, Mo and magnetic signal, indicating a stratified and anaerobic lake; IV) (1963∼1994 CE) increased salinity and productivity with the highest observed magnetic signal and elevated heavy metal and Mo contents, implying enhanced anoxic conditions and human impact; V) (1994∼2003 CE) high C/N, organic and carbonate contents suggesting meromictic and anaerobic lake conditions; VI) (2003∼2020 CE) decreased carbonate content with increased organic C and N, and heavy metals showing a deteriorating lake environment under human impact.
This paper presents a compact broad dual-band rectifier based on a transmission line matching network. This method improves the overall impedance matching performance over two bands, and improves bandwidth of the rectifier’s efficiency. A π-type direct current filter with excellent harmonic suppression performance is proposed. The multi-section transmission line used as the dual-band input impedance matching network is analyzed to achieve an arbitrary frequency ratio. A rectifier is designed and implemented using a three-stage transmission-line matching network. Simulation and experimental results show that a dual-band rectifier is successfully performed with the measured power conversion efficiency (PCE) of 75.7% and 76.3% at 0.915 and 2.45 GHz, respectively. Additionally, the rectifier exhibits bandwidths of 0.48 and 0.25 GHz when the PCE exceeds 70%. Significant enhancement of bandwidth over conventional rectifiers is demonstrated.
A high-energy pulsed vacuum ultraviolet (VUV) solid-state laser at 177 nm with high peak power by the sixth harmonic of a neodymium-doped yttrium aluminum garnet (Nd:YAG) amplifier in a KBe2BO3F2 prism-coupled device was demonstrated. The ultraviolet (UV) pump laser is a 352 ps pulsed, spatial top-hat super-Gaussian beam at 355 nm. A high energy of a 7.12 mJ VUV laser at 177 nm is obtained with a pulse width of 255 ps, indicating a peak power of 28 MW, and the conversion efficiency is 9.42% from 355 to 177 nm. The measured results fitted well with the theoretical prediction. It is the highest pulse energy and highest peak power ever reported in the VUV range for any solid-state lasers. The high-energy, high-peak-power, and high-spatial-uniformity VUV laser is of great interest for ultra-fine machining and particle-size measurements using UV in-line Fraunhofer holography diagnostics.
The migration of Mongolian gazelles (Procapra gutturosa) poses a potential risk of outbreak for zoonotic intestinal protozoan parasite infections. This study aims to investigate the infection status of zoonotic intestinal protozoan parasites in these migratory Mongolian gazelles. We collected 120 fecal samples from Mongolian gazelles during their migration from Mongolia to China in December 2023. These samples were analysed using amplification and sequencing of partial SSU rRNA genes to detect the 4 presence of zoonotic intestinal protozoan parasites and characterize their genotypes. Our analysis revealed the presence of several zoonotic intestinal protozoan parasites in the sampled Mongolian gazelles. Cryptosporidium spp. was detected in 14.17% (17/120) of the samples, followed by Cystoisospora belli in 13.33% (16/120), Blastocystis sp. in 16.67% (20/120) and Cyclospora cayetanensis in 30.00% (36/120). Moreover, we identified novel host-adapted genotypes of Cryptosporidium spp. and C. belli, as well as the presence of ST2 and ST13 Blastocystis sp. subtypes, while distinct genotypes were found in Blastocystis sp. and C. cayetanensis. This study revealed the status of 4 prevalent zoonotic intestinal protozoan parasite infections in Mongolian gazelles and provided crucial insights into their characteristics. The prevalence of these parasites in the population highlights the potential risk of cross-border transmission of infectious diseases associated with long-distance migration. Furthermore, the identification of novel genotypes contributes to our understanding of the genetic diversity and adaptation of these parasites. These findings can inform the development of protective measures to mitigate the impact of these infections on the health and survival of Mongolian gazelles.
In this article, we study the following Schrödinger equation
\begin{align*}\begin{cases}-\Delta u -\frac{\mu}{|x|^2} u+\lambda u =f(u), &\text{in}~ \mathbb{R}^N\backslash\{0\},\\\int_{\mathbb{R}^{N}}|u|^{2}\mathrm{d} x=a, & u\in H^1(\mathbb{R}^{N}),\end{cases}\end{align*}
where $N\geq 3$, a > 0, and $\mu \lt \frac{(N-2)^2}{4}$. Here $\frac{1}{|x|^2} $ represents the Hardy potential (or ‘inverse-square potential’), λ is a Lagrange multiplier, and the nonlinearity function f satisfies the general Sobolev critical growth condition. Our main goal is to demonstrate the existence of normalized ground state solutions for this equation when $0 \lt \mu \lt \frac{(N-2)^2}{4}$. We also analyse the behaviour of solutions as $\mu\to0^+$ and derive the existence of normalized ground state solutions for the limiting case where µ = 0. Finally, we investigate the existence of normalized solutions when µ < 0 and analyse the asymptotic behaviour of solutions as $\mu\to 0^-$.
This paper presents a compact and ultra-wideband high-efficiency microwave rectifier for wireless power transmission (WPT) applications. The input-matching-network utilizes a compact asymmetric coupled transmission line structure, contributing to wideband performance. The rectifier adopts a voltage-doubler topology, resulting in a smooth input impedance across a wide bandwidth. The working principle of the asymmetric coupled transmission line matching network is analyzed. Simulation and measurement are conducted on the proposed rectifier. The fabricated prototype demonstrates a wide bandwidth of 162.5% (0.3–2.9 GHz with the power conversion efficiency (PCE) exceeding 60% at an input power of 18 dBm. Even at an input power of 10 dBm, the measured PCE remains above 50% over the working band. The proposed ultra-wideband rectifier shows promising potential for WPT applications including wireless powering of low-power electronic devices and sensors.
This study examined the sour grapes/sweet lemons rationalization through 2 conditions: ‘attainable’ (sweet lemons) and ‘unattainable’ (sour grapes), reflecting China’s 2019-nCoV vaccination strategy. The aim was to find ways to change people’s beliefs and preferences regarding vaccines by easing their safety concerns and encouraging more willingness to get vaccinated. An online survey was conducted from January 22 to 27, 2021, with 3,123 residents across 30 provinces and municipalities in the Chinese mainland. The direction of belief and preference changed in line with the sour grapes/sweet lemons rationalization. Using hypothetical and real contrasts, we compared those for whom the vaccine was relatively unattainable (‘sour grapes’ condition) with those who could get the vaccine easily (‘sweet lemons’). Whether the vaccine was attainable was determined in the early stage of the vaccine roll-out by membership in a select group of workers that was supposed to be vaccinated to the greatest extent possible, or, by being in the second stage when the vaccine was available to all. The attainable conditions demonstrated higher evaluation in vaccine safety, higher willingness to be vaccinated, and lower willingness to wait and see. Hence, we propose that the manipulation of vaccine attainability, which formed the basis of the application of sour grapes/sweet lemons rationalization, can be utilized as a means to manipulate the choice architecture to nudge individuals to ease vaccine safety concerns, reducing wait-and-see tendencies, and enhancing vaccination willingness. This approach can expedite universal vaccination and its associated benefits in future scenarios resembling the 2019-nCoV vaccine rollout.
Increases in population size are associated with the adoption of Neolithic agricultural practices in many areas of the world, but rapid population growth within the Dingsishan cultural group of southern China pre-dated the arrival of rice and millet farming in this area. In this article, the authors identify starch grains from taros (Colocasia) and yams (Dioscorea) in dental calculus and on food-processing tools from the Dingsishan sites of Huiyaotian and Liyupo (c. 9030–6741 BP). They conclude that the harvesting and processing of these dietary staples supported an Early Holocene population increase in southern East Asia, before the spread of rice and millet farming.
A low-cost and computer-controlled graphitization system connected to an elemental analyzer (EA) has been designed and built at the NTUAMS Lab. This semiautomatic system equips 6-unit reactors for the graphitization of CO2 with H2 on the iron catalyst. The entire procedure takes about 7 hours for iron conditioning, sample combustion and loading, and graphitization. The system can produce good-quality graphite for samples containing 0.5–1.6 mg carbon mass, with the pressure yield of graphitization ranging from 57.7% to 87.1%. The average values of OXI and OXII agree well with the consensus value, but the result of ANU sucrose was observed to be slightly higher than the reported one. The background samples of anthracite over ten months yielded an average of 0.38±0.10 pMC (n=21) corresponding to a 14C age of 45 kyr BP. Intercomparison samples L and M of FIRI exhibit that the measured 14C ages are almost identical to the consensus values and have a small spread in these values. The system has been carrying out graphitization for total organic carbon (TOC) of peat samples, and providing a more efficient and convenient way for AMS 14C dating.
Seven accelerator mass spectrometry radiocarbon (AMS 14C) dates (7260±106∼7607±95 BP averaged 7444±103 BP) on a giant oyster shell, collected from an ancient shore of the Taipei Basin, are similar to the LSC (liquid scintillation counting) 14C age (7260±46 BP) of a grass sample inside the shell. The calibrated 14C ages of the C. gigas by Marine20 are 7490±240∼7805±230 cal BP (average 7660±96 cal BP), generally agreed with the calibrated LSC 14C ages of the grass and the oyster shell. Combined with other 14C ages of shoreline samples in the Taipei Basin, it is evident that sea level rose from 8600 to 7600 cal BP and reached a stand higher than modern sea level. During this marine transgression, the sedimentation rate along the shoreline was very high because 14C dating was not able to detect age differences for 4–5 m thick sediment sequences. Sixty-nine analyses of δ18O and δ13C from the oldest part of the shell exhibit clear seasonal cycles, with a 4-year period of growth in the 5.5-cm section. According to the δ18O values, the ancient oyster grew in a warmer-than-present shoreline environment, suggesting that the current absence of the giant oyster in Taiwan is not due to warming conditions.
Functional montmorillonite can be dispersed in polymer coatings and organic species and polymers can be intercalated into the interlayer space or grafted onto the surface of the functional montmorillonite. The addition of functional montmorillonite into polymer-based coatings can significantly improve anti-corrosion, refractory, super-hydrophobicity, antibacterial activity, and absorption of solar radiation by the resulting montmorillonite/polymer coatings. Montmorillonite can be functionalized for this purpose by ion exchange, intercalation, exfoliation, or combinations of these treatments. The rigid montmorillonite layers interspersed within the polymer matrix inhibit the penetration of corrosive substances, minimize the impact of high-temperature airflow, and thereby lead to strong resistance of the coating to corrosion and fire. The combination of polymers and dispersed montmorillonite nanolayers, which are modified by metal ions, metal oxides, and hydrophobic organic species, allows the resulting composite coating to have quite a rough surface and a much smaller surface free energy so that the montmorillonite/polymer coating possesses superhydrophobicity. The interlayer space of functional montmorillonite can also host or encapsulate antibacterial substances, phase-change materials, and solar energy-absorbing materials. Moreover, it can act as a template to make these guest species exist in a more stable and ordered state. Literature surveys suggest that future work on the functional montmorillonite/polymer coatings should be targeted at the manufacture of functional montmorillonite nanolayers by finding more suitable modifiers and tuning the dispersion and funtionalities of montmorillonite in the coatings.
Organo-montmorillonite (OMnt) has wide applications in paints, clay-polymer nanocomposites, biomaterials, etc. In most cases, the dispersibility and swellability of OMnt dictate the performance of OMnt in the target products. Previous studies have revealed that the properties can be improved when multiple organic species are co-introduced into the interlayer space of montmorillonite (Mnt). In the present study, single surfactant erucylamide (EA), dual-surfactants cetyltrimethyl ammonium bromide (CTAB) and octadecyltrimethyl ammonium chloride (OTAC), and ternary-surfactants EA, CTAB, and OTAC were co-introduced into Mnt by solution intercalation. The resulting OMnts were characterized by powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetry-differential thermogravimetry (TG-DTG), water contact-angle tests, scanning electronic microscopy (SEM), laser particle-size analysis, and swelling indices. Mnt co-modified by ternary CTAB, OTAC, and EA led to a large d001 value (4.20 nm), surface hydrophobicity with a contact angle of 95.6°, swellability (50 mL/g) with small average particle sizes (2.1−2.8 μm) in xylene, and >99% of the OMnt particles were kept as <5 μm in deionized water. The formation of EA-modified-Mnt was proposed according to hydrophobic affinity, hydrogen bonding, and van der Waals forces. The nanoplatelets of the CTA+, OTA+, and EA co-modified OMnts in xylene were assembled into a house-of-cards structure by face-to-edge and edge-to-edge associations. The electrostatic attractions, electrostatic and steric repulsions, and hydrophobic interactions were responsible for the good dispersibility of OMnt in xylene. The ternary surfactant co-modified OMnt with high dispersion and swellability will make OMnt better suited for real-world applications.
The comparisons among 126 14C dates of Carex samples including separated leaf and root parts with acid (A)-treatment and acid-base-acid (ABA)-treatment, and 48 published 14C dates of bulk peat plants on a 92-cm core from Jinchuan Mire in NE China, indicate old carbon influence (OCI) on the 14C dates. The OCI varies with plant species, pretreatment and peat depth. In vascular peat plants such as Carex, humin fractions (remains after ABA treatment) and humic acids are representative of the original plant precursor, while fulvic acids are regarded as the secondary mobile product which should be removed for 14C dating. ABA- treatment removes both fulvic acids and humic acids, whereas A-treatment gets rid of only fulvic acids. Carex roots uptake more dissolved CO2 in peat water. Carex leaves may use more CO2 (involving degassing CO2) above the peat surface. By removing humic acids throughout ABA treatment, the OCI may vary differently over depth (time). ABA treatment cannot eliminate the fixed OCI in humin fractions of vascular peat plants, instead, this treatment may enhance OCI by removing humic acid which may represent the true age of the plants. In addition, Bacon model results on this core could not show rapid changes in accumulation rate.
Schistosomiasis, a parasite infectious disease caused by Schistosoma japonicum, often leads to egg granuloma and fibrosis due to the inflammatory reaction triggered by egg antigens released in the host liver. This study focuses on the role of the egg antigens CP1412 protein of S. japonicum (SjCP1412) with RNase activity in promoting liver fibrosis. In this study, the recombinant egg ribonuclease SjCP1412, which had RNase activity, was successfully prepared. By analysing the serum of the population, it has been proven that the anti-SjCP1412 IgG in the serum of patients with advanced schistosomiasis was moderately correlated with liver fibrosis, and SjCP1412 may be an important antigen associated with liver fibrosis in schistosomiasis. In vitro, the rSjCP1412 protein induced the human liver cancer cell line Hep G2 and liver sinusoidal endothelial cells apoptosis and necrosis and the release of proinflammatory damage-associated molecular patterns (DAMPs). In mice infected with schistosomes, rSjCP1412 immunization or antibody neutralization of SjCP1412 activity significantly reduced cell apoptosis and necroptosis in liver tissue, thereby reducing inflammation and liver fibrosis. In summary, the SjCP1412 protein plays a crucial role in promoting liver fibrosis during schistosomiasis through mediating the liver cells apoptosis and necroptosis to release DAMPs inducing an inflammatory reaction. Blocking SjCP1412 activity could inhibit its proapoptotic and necrotic effects and alleviate hepatic fibrosis. These findings suggest that SjCP1412 may be served as a promising drug target for managing liver fibrosis in schistosomiasis japonica.
In this work, the dynamics of two-dimensional rotating Janus drops in shear flow is studied numerically using a ternary-fluid diffuse interface method. The rotation of Janus drops is found to be closely related to their deformation. A new deformation parameter $D$ is proposed to assess the significance of the drop deformation. According to the maximum value of $D$ ($D_{max}$), the deformation of rotating Janus drops can be classified into linear deformation ($D_{max}\le 0.2$) and nonlinear deformation ($D_{max}> 0.2$). In particular, $D_{max}$ in the former depends linearly on the Reynolds and capillary numbers, which can be interpreted by a mass–spring model. Furthermore, the rotation period $t_R$ of a Janus drop is found to be more sensitive to the drop deformation than to the aspect ratio of the drop at equilibrium. By introducing a corrected shear rate and an aspect ratio of drop deformation, a rotation model for Janus drops is established based on Jeffery's theory for rigid particles, and it agrees well with our numerical results.
The non-archosauriform archosauromorph Dinocephalosaurus orientalis was first described from the Upper Member of the Guanling Formation (late Anisian, Middle Triassic) of Guizhou Province by Li in 2003 on the basis of a complete articulated skull and the first three cervical vertebrae exposed in dorsal to right lateral view. Since then, additional specimens have been discovered in southwestern China. Here, five newly discovered specimens are described for the first time, and redescriptions of the holotype IVPP V13767 and another referred specimen, IVPP V13898, are provided. Together, these permit the description of the complete skeleton of this remarkable long-necked marine reptile. The postcranial skeleton is as much as 6 metres long, and characterised by its long tail and even longer neck. The appendicular skeleton exhibits a high degree of skeletal paedomorphosis recalling that of many sauropterygians, but the skull and neck are completely inconsistent with sauropterygian affinities. The palate does not extend back over the basisphenoid region and lacks any development of the closed condition typical of sauropterygians. The arrangement of cranial elements, including the presence of narial fossae, is very similar to that seen in another long-necked archosauromorph, Tanystropheus hydroides, which at least in part represents a convergence related to an aquatic piscivorous lifestyle. The long and low cervical vertebrae support exceptionally elongate cervical ribs that extend across multiple intervertebral joints and contribute to a ‘stiffening bundle of ribs’ extending along the entire ventral side of the neck, as in many other non-crocopodan archosauromorphs. The functional significance of the extraordinarily elongate neck is hard to discern but it presumably played a key role in feeding, and it is probably analogous to the elongate necks seen in pelagic, long-necked plesiosaurs. Dinocephalosaurus orientalis was almost certainly a fully marine reptile and even gave birth at sea.
This study aimed to develop and evaluate a scenario-based nutrition literacy (NL) online programme for Taiwanese college students.
Design:
A randomised pilot trial design was used in this study.
Setting:
The study was conducted at a university in Taiwan. The intervention consisted of a five-unit web-based NL programme including videos of real-life scenario-based stories, situational analysis teaching and after-unit quizzes. Theme-related website information and smartphone apps (both iOS and Android systems) were offered for reference in every unit. The NL measure consisted of a self-rated scale, a scenario-based test and a healthy eating behaviour survey. Paired sample t-tests and ANCOVA were performed to test the effects on NL and healthy eating behaviour.
Participants:
Participants were ninety-eight students, with a retention rate of 98 %. The ratio of men to women was 0·2:1. Most students were freshmen (48 %).
Results:
Compared with the control group, the experimental group showed significant post-intervention improvements in the NL and healthy eating behaviours after controlling for pretest scores.
Conclusions:
This pilot study offers preliminary evidence of the potential positive effects of implementing a scenario-based NL online programme for college students. It offers a possibly novel strategy to enhance health-promoting behaviours in Taiwanese universities. Further research with larger sample sizes and more rigorous designs is warranted to confirm and build upon these initial findings.