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Natural clays are often employed as substrates for heterogeneous catalysts. However, the direct use of raw clays as catalysts has received less research attention. The objective of the present study was to help fill this gap by investigating catalytic properties of raw pelagic clays (PC) collected from the Indian Ocean. The raw PC were discovered to be efficient catalysts in the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4. The effects of parameters including pH values, dosages of PC, and initial concentration of 4-NP and NaBH4 on the conversion or degradation rate of 4-NP have been investigated. The 4-NP was observed to be completely degraded within 480 s under conditions of 0.10 mM 4-NP, 25.0 mM NaBH4, and 0.20 g/L PC at an initial pH value of 7.0. The apparent rate constant was evaluated to be 27.53 × 10–3 s–1. Unlike previous pseudo-first order kinetics experiments, the induction period and degradation stages were observed to occur simultaneously during the PC catalysis. The S-shaped kinetics for 4-NP conversion was found to be perfectly matched by Fermi's function, and the enzyme-like catalysis by PC was appointed to describe the kinetics. Species of Fe(III), Mn(IV), and Mn(III) in PC were found to be essential, and were partly reduced to Fe(0) and Mn(II) by NaBH4 in our reaction, contributing to rapid conversion of 4-NP to 4-aminophenol (4-AP). The raw PC was converted to magnetic PC (m-PC) particles, which made PC particles separate easily for cycling use. This discovery would also have applications in continuous flow-fluid catalysis.
Broomcorn millet and foxtail millet were first cultivated in Neolithic China then the process spread west across Asia during the Bronze Age. But the distinctive ceramic, and later bronze, vessels utilised in East Asian cuisines for boiling and steaming grains did not move west alongside these crops. Here, the authors use measurements of 3876 charred millet grains to evaluate regional variations and implications for food preparation. In contrast to wheat grains, which became smaller as their cultivation moved east, millet grains became larger as they spread from northern China into Inner Asia and Tibet. This indicates the decoupling of millets from associated cooking techniques as they reached geographical and cultural areas.
Social hierarchical information impacts language comprehension. Nevertheless, the specific process underlying the integration of linguistic and extralinguistic sources of social hierarchical information has not been identified. For example, the Chinese social hierarchical verb 赡养, /shan4yang3/, ‘support: provide for the needs and comfort of one’s elders’, only allows its Agent to have a lower social status than the Patient. Using eye-tracking, we examined the precise time course of the integration of these semantic selectional restrictions of Chinese social hierarchical verbs and extralinguistic social hierarchical information during natural reading. A 2 (Verb Type: hierarchical vs. non-hierarchical) × 2 (Social Hierarchy Sequence: match vs. mismatch) design was constructed to investigate the effect of the interaction on early and late eye-tracking measures. Thirty-two participants (15 males; age range: 18–24 years) read sentences and judged the plausibility of each sentence. The results showed that violations of semantic selectional restrictions of Chinese social hierarchical verbs induced shorter first fixation duration but longer regression path duration and longer total reading time on sentence-final nouns (NP2). These differences were absent under non-hierarchical conditions. The results suggest that a mismatch between linguistic and extralinguistic social hierarchical information is immediately detected and processed.
Long-term time series of annual glacier mass balance is important for revealing a glacier's response to regional climate variations. However, for the Tibetan Plateau, time series of annual glacier mass balance with more than 10 consecutive years remains scarce due to the inaccessibility and harsh climate conditions. In this study, we established an albedo-based model to reconstruct annual glacier mass balance for 2000–20 over the Dongkemadi Glacier, based on multitemporal geodetic estimates and annual minimum glacier-wide mean surface albedos. Geodetic glacier mass-balance estimates for 2000–12, 2012–14 and 2014–18 were obtained by comparing glacier surface topographic data. Minimum surface albedos were obtained from the moderate-resolution imaging spectroradiometer daily snow albedo products for 2000–20. The estimated results are supported by the field measurements of annual glacier mass balance. During the early 2000s, we detected a relatively balanced state of glacier mass change, whereas a pronounced mass loss of more than −0.5 m w.e. was found for most years in the 2010s. By analyzing the regional climate variations with the ERA5-Land monthly averaged data, we found that the accelerated glacier mass loss can be attributed to both decreased annual snowfall and increased summer air temperature.
This study presents novel findings on stochastic electron heating via a random electron cyclotron wave (ECW) in a spherical tokamak. Hard x ray measurements demonstrate the time evolution of hard x ray counts at different energy bands, consistent with predictions from the stochastic heating model. The ECW heating rate shows a positive correlation with applied power, confirming the effectiveness of stochastic heating. Remarkably, the ECW-driven plasma current remains insensitive to ECW incidence angle, consistent with model predictions. The observed stochastic heating of electrons offers potential for exploring innovative non-inductive current drive modes in spherical tokamaks. This research contributes to the understanding of plasma behaviour and motivates the development of new models for non-inductive current drive in fusion devices.
In a recent survey of nematodes associated with tobacco in Shandong, China, the root-lesion nematode Pratylenchus coffeae was identified using a combination of morphology and molecular techniques. This nematode species is a serious parasite that damages a variety of plant species. The model plant benthi, Nicotiana benthamiana, is frequently used to study plant-disease interactions. However, it is not known whether this plant species is a host of P. coffeae. The objectives of this study were to evaluate the parasitism and pathogenicity of five populations of the root-lesion nematode P. coffeae on N. benthamiana.N. benthamiana seedlings with the same growth status were chosen and inoculated with 1,000 nematodes per pot. At 60 days after inoculation, the reproductive factors (Rf = final population densities (Pf)/initial population densities (Pi)) for P. coffeae in the rhizosphere of N. benthamiana were all more than 1, suggesting that N. benthamiana was a good host plant for P. coffeae.Nicotiana. benthamiana infected by P. coffeae showed weak growth, decreased tillering, high root reduction, and noticeable brown spots on the roots. Thus, we determined that the model plant N. benthamiana can be used to study plant-P. coffeae interactions.
To comprehensively study the physical properties of inductively coupled plasma (ICP), a finite element method (FEM) simulation model of ICP is developed using the well-established COMSOL software. To benchmark the validation of the FEM model, two key physical parameters, the electron density and the electron temperature of the ICP plasma, are precisely measured by the state-of-the-art laser Thomson scattering diagnostic approach. For low-pressure plasma such as ICP, the local pressure in the generator tube is difficult to measure directly. The local gas pressure in the ICP tube has been calibrated by comparing the experimental and simulation results of the maximum electron density. And on this basis, the electron density and electron temperature of ICP under the same gas pressure and absorbed power have been compared by experiments and simulations. The good agreement between the experimental and simulation data of these two key physical parameters fully verifies the validity of the ICP FEM simulation model. The experimental verification of the ICP FEM simulation model lays a foundation for further study of the distribution of various physical quantities and their variation with pressure and absorption power, which is beneficial for improving the level of ICP-related processes.
The laser-induced damage threshold (LIDT) of plate laser beam splitter (PLBS) coatings is closely related to the subsurface absorption defects of the substrate. Herein, a two-step deposition temperature method is proposed to understand the effect of substrate subsurface impurity defects on the LIDT of PLBS coatings. Firstly, BK7 substrates are heat-treated at three different temperatures. The surface morphology and subsurface impurity defect distribution of the substrate before and after the heat treatment are compared. Then, a PLBS coating consisting of alternating HfO2–Al2O3 mixture and SiO2 layers is designed to achieve a beam-splitting ratio (transmittance to reflectance, s-polarized light) of approximately 50:50 at 1053 nm and an angle of incidence of 45°, and it is prepared under four different deposition processes. The experimental and simulation results show that the subsurface impurity defects of the substrate migrate to the surface and accumulate on the surface during the heat treatment, and become absorption defect sources or nodule defect seeds in the coating, reducing the LIDT of the coating. The higher the heat treatment temperature, the more evident the migration and accumulation of impurity defects. A lower deposition temperature (at which the coating can be fully oxidized) helps to improve the LIDT of the PLBS coating. When the deposition temperature is 140°C, the LIDT (s-polarized light, wavelength: 1064 nm, pulse width: 9 ns, incident angle: 45°) of the PLBS coating is 26.2 J/cm2, which is approximately 6.7 times that of the PLBS coating deposited at 200°C. We believe that the investigation into the laser damage mechanism of PLBS coatings will help to improve the LIDT of coatings with partial or high transmittance at laser wavelengths.
Homeostasis of gut microbiota is a critical contributor to growth and health in weaned piglets. Fish oil is widely reported to benefit health of mammals including preventing intestinal dysfunction, yet its protective effect during suckling-to-weaning transition in piglets remains undetermined. Low (30 g/d) and high (60 g/d) doses of n-3-rich fish oil were supplemented in sows from late gestation to lactation. Serum indicators and gut microbiota were determined to evaluate the effects of maternal fish oil on growth performance, immunity and diarrhea of piglets. DHA and EPA in the colostrum as well as serum of suckling and 1-week post-wean piglets were significantly and linearly increased by maternal supplementation of fish oil (P < 0.05). IGF1 and T3 in nursing and weaned piglets were significantly elevated by maternal fish oil (P < 0.05), and the increase of IGF1 was concerning the dosage of fish oil. Colostrum IgG, plasma IgG, IgM in suckling piglets, IgG, IgM and IgA in weaned piglets were significantly increase as maternal replenishment of fish oil increased (P < 0.05). Additionally, cortisol was significantly reduced in weaned pigs (P < 0.05), regardless of dosage. 16S rRNA sequencing revealed that α-diversity of fecal microbiota in nursery piglets, and fecal Lactobacillus genus, positively correlated with post-weaning IgA, was significantly increased by high dosage. Collectively, maternal fish oil during late pregnancy and lactation significantly promoted growth, enhanced immunity, and reduced post-weaning diarrhea in piglets, therefore facilitated suckling-to-weaning transition in piglets, which may be partially due to the altered gut microbial community.
Clay-swelling inhibitors are often used to prevent the hydration of clay minerals, which can reduce the risk of wellbore instability and reservoir damage. The molecular behaviour of clay-swelling inhibitors at the montmorillonite–water interface is crucial for revealing their inhibition mechanisms and for evaluating and designing inhibitor molecules. N1,N1'-(ethane-1,2-diyl)bis(N1-(2-aminoethyl)ethane-1,2-diamine) (NETS), a low-molecular-weight clay-swelling inhibitor, is used widely to prevent clay swelling. Herein, the adsorption mechanism of NETS on the surface of montmorillonite (Mnt) was investigated using molecular dynamics (MD) simulations. In particular, the effects of molecular conformation and temperature on adsorption ability were investigated. The results show that the adsorption ability of NETS on the Mnt surface was affected significantly by the molecular conformation. Specifically, the dihedral angle of NETS adsorbed on the surface of Mnt decreases by ~20° and tends to adsorb on the surface of Mnt in a plane state. In addition, the adsorption stability of NETS on the Mnt surface decreased with increasing temperature, as was found using MD simulations. Detailed analysis shows that increasing temperature can lead to more frequent conformational changes, which weaken the interaction between NETS and Mnt, thus reducing adsorption stability. These molecular insights into the interaction mechanism between NETS and Mnt are beneficial for the evaluation of inhibitory effects and for the selection and molecular design of new clay-swelling inhibitors for use in drilling fluids.
In this study, a toroidal quartz (
$20\overline{2}3$
) crystal is designed for monochromatic X-ray imaging at 72.3°. The designed crystal produces excellent images of a laser-produced plasma emitting He-like Ti X-rays at 4.75 keV. Based on the simulations, the imaging resolutions of the spherical and toroidal crystals in the sagittal direction are found to be 15 and 5 μm, respectively. Moreover, the simulation results show that a higher resolution image of the source can be obtained by using a toroidal crystal. An X-ray backlight imaging experiment is conducted using 4.75 keV He-like Ti X-rays, a 3 × 3 metal grid, an imaging plate and a toroidal quartz crystal with a lattice constant of 2d = 0.2749 nm. The meridional and sagittal radii of the toroidal α-quartz crystal are 295.6 and 268.5 mm, respectively. A highly resolved image of the microgrid, with a spatial resolution of 10 μm, is obtained in the experiment. By using similar toroidal crystal designs, the application of a spatially resolved spectrometer with high-resolution X-ray imaging ability is capable of providing imaging data with the same magnification ratio in the sagittal and meridional planes.
Various coatings in high-power laser facilities suffer from laser damage due to nodule defects. We propose a nodule dome removal (NDR) strategy to eliminate unwanted localized electric-field (E-field) enhancement caused by nodule defects, thereby improving the laser-induced damage threshold (LIDT) of laser coatings. It is theoretically demonstrated that the proposed NDR strategy can reduce the localized E-field enhancement of nodules in mirror coatings, polarizer coatings and beam splitter coatings. An ultraviolet (UV) mirror coating is experimentally demonstrated using the NDR strategy. The LIDT is improved to about 1.9 and 2.2 times for the UV mirror coating without artificial nodules and the UV mirror coating with artificial nodule seeds with a diameter of 1000 nm, respectively. The NDR strategy, applicable to coatings prepared by different deposition methods, improves the LIDT of laser coating without affecting other properties, such as the spectrum, stress and surface roughness, indicating its broad applicability in high-LIDT laser coatings.
The selection of high-quality sperms is critical to intracytoplasmic sperm injection, which accounts for 70–80% of in vitro fertilization (IVF) treatments. So far, sperm screening is usually performed manually by clinicians. However, the performance of manual screening is limited in its objectivity, consistency, and efficiency. To overcome these limitations, we have developed a fast and noninvasive three-stage method to characterize morphology of freely swimming human sperms in bright-field microscopy images using deep learning models. Specifically, we use an object detection model to identify sperm heads, a classification model to select in-focus images, and a segmentation model to extract geometry of sperm heads and vacuoles. The models achieve an F1-score of 0.951 in sperm head detection, a z-position estimation error within ±1.5 μm in in-focus image selection, and a Dice score of 0.948 in sperm head segmentation, respectively. Customized lightweight architectures are used for the models to achieve real-time analysis of 200 frames per second. Comprehensive morphological parameters are calculated from sperm head geometry extracted by image segmentation. Overall, our method provides a reliable and efficient tool to assist clinicians in selecting high-quality sperms for successful IVF. It also demonstrates the effectiveness of deep learning in real-time analysis of live bright-field microscopy images.
For individual cultures, findings on regulating embryo density by changing the microdrop volume are contradictory. The aim of this study was to investigate the relationship between embryo density and the developmental outcome of day 3 embryos after adjusting covariates. In total, 1196 embryos from 206 couples who had undergone in vitro fertilization treatment were analyzed retrospectively. Three embryo densities were used routinely, i.e. one embryo in a drop (30 μl/embryo), two embryos in a drop (15 μl/embryo) and three embryos in a drop (10 μl/embryo). Embryo quality on day 3 was evaluated, both the cell number of day 3 embryos and the proportion of successful implantations served as endpoints. Maternal age, paternal age, antral follicles and level of anti-Müllerian hormone, type of infertility, controlled ovarian stimulation protocol, length of stimulation, number of retrieved oocytes, number of zygotes (two pronuclei) and insemination type were covariates and adjusted. After adjusting fully for all covariates, the cell number of day 3 embryos was significantly increased by 0.40 (95% CI 0.00, 0.79; P = 0.048) and 0.78 (95% CI 0.02, 1.54; P = 0.044) in the 15 μl/embryo and 10 μl/embryo group separately, compared with the 30 μl/embryo group. The proportions of implanted embryos were 42.1%, 48.7% and 0.0% in the 30 μl/embryo, 15 μl/embryo and 10 μl/embryo groups respectively. There was no statistical significance (P = 0.22) between the 30 μl/embryo group and the 15 μl/embryo group. After adjusting for confounders that were significant in univariate analysis, embryo density was still not associated with day 3 embryo implantation potential (P > 0.05). In a 30-μl microdrop, culturing embryos with an embryo density of both 15 and 10 μl/embryo increased the cell number of day 3 embryos, which did not benefit embryo implanting potential, compared with individual culture of 30 μl/embryo.
South-west China, particularly between the Himalayas and the Beibu Gulf, constitutes an important corridor for migratory raptors along the East-Asian continental flyway. However, a lack of ornithological assessment and the common practice of illegal hunting in this region emphasize the need for research and conservation actions. To investigate the ecology of migration and scale of persecution, we launched one of the first citizen-science projects in mainland China to record southward-migrating raptors and hunting gunshots from 2015 to 2019 on Guantouling, a well-known raptor site in South-west China. A total of 42,891 raptors were recorded, belonging to 30 diurnal raptor species. Grey-faced Buzzard Butastur indicus, Oriental Honey Buzzard Pernis ptilorhynchus and Amur Falcon Falco amurensis were the three most abundant species recorded. The bulk of Grey-faced Buzzard and Amur Falcon migrated through Guantouling from mid-October till early November, while Oriental Honey Buzzard migrated throughout October and early November. Precipitation slowed down migration significantly while increasing cloud cover was favoured by the three most abundant species. We found hunting mostly occurred in the afternoon, coinciding with an increasing number of Oriental Honey Buzzard, which may become a major victim of hunting. It is thus suggested to prioritize peak raptor migration period for law enforcement actions, especially on cloudy days and after passage of cold fronts, when Oriental Honey Buzzards and other species are likely to migrate. The annual counting scheme on Guantouling is not only an ecological survey, but also an effective way of engaging the public to counter raptor persecution.