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We propose a simultaneous multifrequency near-field radio holography method for measuring reflector surfaces of radio telescopes with high precision. With a comb spectrum generator as the beacon source, this method can obtain aperture phase maps at multiple frequencies simultaneously and thereby reduce the interference of multipath signals and improve the measurement precision of radio holography. The simulation and analysis of the multipath effect on antenna beam pattern measurement are presented. A simultaneous multifrequency near-field holography system operating at the W-band is built for experimental validation. Demonstrating experiment conducted on a 1.2-m aperture submillimeter antenna is reported and discussed.

Exfoliation corrosion (EFC) has rarely been reported for wrought magnesium alloys. Enhanced EFC of the as-extruded Mg–1Li–1Ca alloy was observed after the removal of outermost fine-grained skins. The microstructure and corrosion products were investigated using optical microscopy, scanning electron microscopy, electron backscattered diffraction, X-ray diffraction, and Fourier transform infrared spectrometry. The corrosion behavior was analyzed using electrochemical polarization, electrochemical impedance spectroscopy, and scanning Kelvin probe techniques. The results indicated that the surface of Mg–1Li–1Ca, with the superficial layer removed, was more susceptible to EFC. A linear correlation between grain boundary density and corrosion resistance was established. Additionally, the influence of factors such as grain size, intermetallic compounds, different alloy surfaces, and corrosion products on EFC were discussed, and the corresponding EFC mechanism was clarified.

The effect of oxalic acid (OA) etching on the formation mechanism and corrosion performance of in-situ steam Mg−Al layered double hydroxide (LDH) coatings on AM50 Mg alloy was investigated by exposing the intermetallic compounds (β-Mg17Al12and AlMn) on the surface of the alloy. The results demonstrated that the presence of OA led to an increased fraction of intermetallic compounds on the Mg substrate. Mg−Al LDH nucleated and grew around the Al−Mn phase. The best corrosion resistance of LDH coating was obtained with the maximum thickness at a pickling time of 45 s, and the corrosion current density was reduced by three orders of magnitude compared to the substrate. Finally, the formation mechanism of Mg−Al LDH coating on AM50 Mg alloy was proposed.

Biomimetic graphene−epoxy composite coating was fabricated with a “brick and mud” structure via a spin-coating strategy. Imidazolium-based ionic liquids modified graphene (GI) was synthesized to improve the interfacial compatibility between the graphene (G) layers and epoxy resin. The surface morphology and chemical structures were observed and analyzed through scanning electron microscopy (FE-SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) as well as Fourier transform infrared spectroscopy (FTIR). The thermal imager was used to record the temperature change on the surface. The surface resistivity and thermal conductivity of the coating were determined via volumetric surface area resistivity tester and laser flash method, respectively. The corrosion resistance was investigated through electrochemical impedance spectroscopy (EIS) and salt spray testing. The GI layers in the composite coating exhibited a near-parallel orientation, which led to improved heat transfer and electrostatic dissipative efficiency. The through-plane thermal conductivity and surface resistivity were 0.77 W·m−1·K−1and 1.6×106Ω·cm, respectively. Electrochemical impedance spectroscopy tests revealed that the low-frequency modulus of the coating reached 6.76×1010Ω·cm2after 40 d of immersion, which was about two orders of the magnitude higher than that of the pure epoxy coating, showing a superior corrosion resistance.

Mg-1 wt.% Li-1 wt.% Ca (LX11) and Mg-4 wt.% Li-1 wt.% Ca (LX41) alloys share the same hexagonal closed-packed crystalline structure. However, the differences in microstructure, mechanical properties, and degradation rates between the two alloys are not well understood. Hereby, the above three aspects of LX11 and LX41 alloys were studied via optical microscopy, tensile tests, and electrochemical polarization and electrochemical impedance spectroscopy, together with hydrogen evolution. The concentration of the released Mg2+, Ca2+, and Li+ions was analyzed using a flame atomic absorption spectrophotometer. Results demonstrated that the LX11 alloy was composed of finer α-Mg grains, fewer twins, and smaller volume fractions of the intermetallic phases Mg2Ca than the LX41 alloy. The increasing Li concentration generated a weak decrease in the yield strength of the Mg–Li–Ca alloys, a remarkable increase in elongation to failure, and a stable ultimate tensile strength. The LX11 alloy had better corrosion resistance than the LX41 alloy. The release rate of the cations (Mg2+, Ca2+, and Li+) varied significantly with time. The release rate of metallic ions in Hank's solution cannot reflect the true corrosion rate of Mg–Li–Ca alloys due to the formation of the precipitated corrosion products and their difference in solubility. The dealloying corrosion mechanism of the Mg2Ca phase in Mg–Li–Ca alloys was proposed.

• Smart coating was constructed by incorporating fluorescent polydopamine into thermo-responsive epoxy resin. • Dynamic damage-healing behaviors in anticorrosion coating were visualized and traced by fluorescence signals. • NIR irradiation effectively contributed to crack closure and thus inhibited the localized corrosion reactivity. • The composite coating possessed efficient healing and durable anticorrosion performance. Polymeric coatings are susceptible to microdefects that are difficult to detect thus leading to premature failure of metallic components or even catastrophic accidents. Although obtaining considerable progress in damage healing and detecting, it is still challenging for anticorrosion coating to realize warning the damage generation and tracing the healing process simultaneously. This article validates a robust strategy based on damage-induced fluorescence enhancement effect to visualize dynamic damage-healing processes in anticorrosion coatings on magnesium alloy AZ31. Through embedding fluorescent polydopamine nanoparticles into thermo-responsive epoxy resin, immediate fluorescence was intensified at coating damages. Localized electrochemical impedance and salt spray results proved that the prepared coating possessed pronounced healing and corrosion protection capability with near-infrared irradiation. Notably, the healing behavior can be traced and visualized based on the decrease in fluorescence intensity. This work opens a new avenue to monitor the failure and self-healing mechanism of anticorrosion coatings, providing guideline for engineering of next generation smart protection materials. [Display omitted] [ABSTRACT FROM AUTHOR]

The impact of the anodic second phase, Mg41Nd5in as-extruded Mg–4Li-3Nd-0.2Zn alloy was first reported as a candidate anode material for primary Mg-air batteries. Solid solution treatment of Mg–4Li-3Nd-0.2Zn was conducted at 400, 450, and 500 °C for 8 h. The electrochemical behaviour and discharge performance were investigated using microstructural characterization, electrochemical measurements, and discharge tests. The results indicated that solid solution treatment led to increased grain size and reduced volume fraction of the anodic second phase (Mg41Nd5) with a uniform distribution. In turn, the anode electrochemical activity was promoted, and the bulk effect was reduced. The anode efficiency and comparison capacity were significantly improved. At 5 mA cm−2, the average discharge voltage reached as high as 1.45 V with a utilization efficiency of 61.29%, and a discharge capacity of 1358.98 mAh·g−1for the solid solution-treated sample at 450 °C, making it the excellent candidate anode material for Mg-air batteries.

Pulmonary fibrosis (PF) is a chronic interstitial lung disease with no effective therapies. Galectin-3 (Gal-3), a marker of oxidative stress, plays a key role in the pathogenesis of PF. Fibroblast-myofibroblast differentiation (FMD) is an important source of fibrotic cells in PF. Previous studies showed that melatonin (MT) exerted anti-fibrotic effect in many diseases including PF through its antioxidant activity. In the present study we investigated the relationships among Gal-3, NRF2, ROS in FMD and their regulation by MT. We established an in vitro model of FMD in TGF-β1-treated human fetal lung fibroblast1 (HFL1) cells and a PF mouse model viableomycin (BLM) intratracheal instillation. We found that Gal-3 expression was significantly increased both in vitro and in vivo. Knockdown of Gal-3 in HFL1 cells markedly attenuated TGF-β1-induced FMD process and ROS accumulation. In TGF-β1-treated HFL1 cells, pretreatment with NRF2-specific inhibitor ML385 (5 μM) significantly increased the levels of Gal-3, α-SMA and ROS, suggesting that the expression of Gal-3 was regulated by NRF2. Treatment with NRF2-activator MT (250 μM) blocked α-SMA and ROS accumulation accompanied by reduced Gal-3 expression. In BLM-induced PF model, administration of MT (5 mg·kg−1·d−1, ip for 14 or 28 days) significantly attenuated the progression of lung fibrosis through up-regulating NRF2 and down-regulating Gal-3 expression in lung tissues. These results suggest that Gal-3 regulates TGF-β1-induced pro-fibrogenic responses and ROS production in FMD, and MT activates NRF2 to block FMD process by down-regulating Gal-3 expression. This study provides a useful clue for a clinical strategy to prevent PF.

• A curcumin loaded coating with flake structure prepared on AZ31 alloy. • Coating displays anticorrosion and antibacterial ability with low cytotoxicity. • High photothermal conversion efficiency and photothermal antibacterial coating on AZ31 alloy surface. • A new double antibacterial coating preparation method for the Mg bone implants is provided. • β -CD and SA used to enhance bioavailability of curcumin and binding force. It is a challenging task to prepare a coating on Mg alloys for desirable corrosion resistance, good antibacterial ability and biocompatibility. In this research work, an in-situ Mg(OH) 2 coating incorporated with sodium alginate (SA) and β -cyclodextrin (β -CD)@curcumin (Cur) was formed on the surface of micro arc oxidation (MAO) coated AZ31 alloy via a low temperature hydrothermal method. Characterization techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FT-IR) and scanning electron microscope (SEM) were employed to characterize the chemical composition and surface morphology of the coatings. The corrosion protection ability of the coatings was monitored via electrochemical polarization, hydrogen evolution and immersion tests. Photothermal antibacterial ability and cytocompatibility of the coatings were evaluated by plate counting method under the irradiation of 808 nm-near infrared light, in vitro cytotoxicity tests (MTT) and live/dead cell staining. The results indicate that a chelation of the organic molecules led to the formation of a MAO/(β -CD@Cur)-SA-Mg(OH) 2 coating with excellent corrosion protection, multi- antibacterial ability and almost no toxicity to the cells. Especially, the coating provided photothermal performance through the light absorption of Cur, which was encapsulated by β -CD to improve its bioavailability. SA enhanced the binding force between the drug and the substrate. This novel coating designated the potential application on bioabsorbable magnesium alloys. [ABSTRACT FROM AUTHOR]

Surgical failures, caused by postoperative infections of bone implants, are commonly met, which cannot be treated precisely with intravenous antibiotics. Photothermal therapy (PTT) and photodynamic therapy (PDT) have attracted widespread attention due to their non-invasive antibacterial effects on tissues and no bacterial resistance, which may be an excellent approach to solve infections related to bone implants for biodegradable magnesium alloys. Herein, a sodium copper chlorophyllin (SCC) with a porphyrin ring induced Ca–P coating was prepared on AZ31 magnesium alloy via layer-by-layer (LbL) assembly. The morphology and composition of the samples were characterized through field emission scanning electron microscope (FE-SEM) with affiliated energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), and Fourier infrared spectrometer (FTIR) and X-ray photoelectron spectrometer (XPS) as well. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and hydrogen evolution experiments were employed to evaluate the corrosion behavior of the samples. Atomic absorption spectrophotometer was used to measure Cu elemental content of different immersion periods. Cytocompatibility and antibacterial performance of the coatings were probed using in vitrocytotoxicity tests (MTT assay), live/dead cell staining and plate counting method. The results showed that the obtained (Ca–P/SCC)10coating exhibited good corrosion resistance, antimicrobial activity (especially under 808 nm irradiation) and biocompatibility. The antibacterial rates for E. coliand S. aureuswere 99.9% and 99.8%, respectively; and the photothermal conversion efficiency was as high as 42.1%. Triple antibacterial mechanisms including photodynamic, photothermal reactions and copper-ions release were proposed. This coating exhibited a promising application for biodegradable magnesium alloys.

The influence of intermetallic Al-Mn particles on the corrosion behavior of in-situ formed Mg-Al layered double hydroxide (Mg-Al-CO32--LDH) steam coating on AZ31 Mg alloy was investigated. The alloy was pretreated with H3PO4, HCl, HNO3or citric acid (CA), followed by hydrothermal treatment, for the fabrication of Mg-Al-LDH coating. The microstructure, composition and corrosion resistance of the coated samples were investigated. The results showed that the surface area fraction of Al-Mn phase exposed on the surface of the alloy was significantly increased after CA pretreatment, which promotes the growth of the Mg-Al-LDH steam coating. Further, the LDH-coated alloy pretreated with CA possessed the most compact surface and the maximum coating thickness among all the coatings. The corrosion current density of the coated alloy was decreased by three orders of magnitude as compared to that of the bare alloy.

Qinghai‒Tibet Plateau (QTP) is one of the most sensitive regions to climate change in the world. As a result, people in the QTP are more likely to be sensitively affected by climate change than those in other regions, particularly in the poverty area. Using the Universal Thermal Climate Index (UTCI) derived from ERA5 and population data, changes in annual thermal comfort condition and population under such condition in the QTP are systematically analyzed. The results reveal that there is considerable regional heterogeneity in the distribution of UTCI and the number of comfortable days (CDs), mainly due to the complex geographic features. In most areas of the QTP, the increase in UTCI leads to an increased number of comfortable days. Spatial distribution and temporal change in the number of comfortable days are found to be principally related to altitude. In areas within altitudes of 3000–4500 m, the number of comfortable days increases by up to 6 d per decade, which is faster than that in higher elevation areas above 4500 m. Results also indicate that thermal comfortable condition has improved in areas of 2500–5000 m (medium to high altitude), particularly in spring and autumn. Further research indicates that population distribution also shows a regional clustering feature, with the majority of residents residing in cities and their vicinities, where a higher number of comfortable days were observed. Most areas with a greater number of comfortable days have experienced a more significant increase in population under thermal comfortable conditions. It implies that climate change more likely has a large influence on population in the QTP. These findings are expected to enhance tourism development and the assessment of the impact on the living environment. The findings can be helpful for optimizing of tourism development and better understanding how climate change affects population distribution.

A Schiff base (a compound containing a C=N bond) induced anodic Ca–P coating was prepared on AZ31 Mg alloy in a mixed solution of CaCl2and KH2PO4at 60 °C in the presence of glucose and L-cysteine. The microstructure and chemical composition of the coatings were characterized using FE-SEM, FT-IR, XRD, and XPS. The in vitro degradation resistance of the coated samples was evaluated via potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and hydrogen evolution test. The experimental results show that the Ca–PSchiff basecoating is composed of CaHPO4(DCPA) and hydroxyapatite (HA), whereas HA is not present in the Ca–P coating. The Ca−PSchiff basecoating thickness is about 2 times that of Ca–P coating (Ca−P coating: (9.13±4.20) μm and Ca–PSchiff base: (18.13±5.78) μm). The corrosion current density of the Ca–PSchiff basecoating is two orders of magnitude lower than that of the Ca–P coating. The formation mechanism of the Ca–PSchiff baseis proposed.

Magnesium (Mg) and its alloys are considered as ideal biodegradable materials due to their excellent mechanical properties and biocompatibility. In order to improve the surface properties to allow better adaptation to the surrounding tissue of the body, surface modification has played a significant role in satisfying multiple clinical requirements such as corrosion resistance, biocompatibility, and antibacterial ability. Here, layer-by-layer (LbL) self-assembly, which can be applied for biodegradable Mg alloys due to its extensive choice of usable units, holds great promise among all the surface techniques. In this review, the mechanisms of the driving force (i.e., electrostatic interaction, hydrogen bonding, charge transfer interaction and covalent bonding), cutting-edge advances in preparation methods (e.g., dipping, spraying, and spinning) and the functional properties (corrosion resistance, antibacterial activity, and biocompatibility) that could be achieved by the LbL coatings are summarized. A reasonable trend of the potential development of LbL for bio-Mg alloys is also proposed at the end of this article.

A hydrothermal deposition method was utilized to fabricate Ca-P composite coating induced by the layer-by-layer (LbL) assembled polyvinylpyrrolidone/deoxyribonucleic acid (PVP/DNA)20multilayer on AZ31 alloy. The surface morphology and compositions were characterized by SEM, EDS, FTIR and XRD. Besides, the corrosion resistance and degradation behavior of the coating were tested via electrochemical polarization, impedance spectroscopy and immersion measurements. Results show that the main components of Ca-P coatings are hydroxyapatite, Ca3(PO4)2and Mg3(PO4)2·nH2O. The LbL-assembled DNA and PVP promote the adsorption of Ca-P deposits on the sample surface, and structures and functional groups of the polyelectrolyte in the outermost layer are the primary influencing factor for the induction of the Ca-P coating. Carboxyl groups have the best biomineralization effect among all related functional groups. The enhanced corrosion resistance and adhesion highlight a promising use of (PVP/DNA)20-induced Ca-P coatings in the field of biomedical magnesium alloys.

[Display omitted] • The Volta potential of Mg 41 Nd 5 phase is more negative than that of α-Mg. • The dealloying mechanism of Mg 41 Nd 5 is proposed. • Nd-rich films endow the alloys good corrosion resistance. • T4 treatment led to a shift from pitting corrosion to uniform corrosion. • The "ring-shaped" corrosion is discussed. The microstructure and chemical compositions of the solid solution-treated Mg-3Nd-1Li-0.2Zn alloy were characterized using optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), electron probe micro-analyzer (EPMA) and X-ray photoelectron spectroscopy (XPS). The corrosion behaviour of the alloy was investigated via electrochemical polarization, electrochemical impedance spectroscopy (EIS), hydrogen evolution test and scanning Kelvin probe (SKP). The results showed that the microstructure of the as-extruded Mg-3Nd-1Li-0.2Zn alloy contained α -Mg matrix and nanometric second phase Mg 41 Nd 5. The grain size of the alloy increased significantly with the increase in the heat-treatment duration, whereas the volume fraction of the second phase decreased after the solid solution treatment. The surface film was composed of oxides (Nd 2 O 3 , MgO, Li 2 O and ZnO) and carbonates (MgCO 3 and Li 2 CO 3), in addition to Nd. The as-extruded alloy exhibited the best corrosion resistance after an initial soaking of 10 min, whereas the alloy with 4h-solution-treatment possessed the lowest corrosion rate after a longer immersion (1 h). This can be attributed to the formation of Nd-containing oxide film on the alloys and a dense corrosion product layer. The dealloying corrosion of the second phase was related to the anodic Mg 41 Nd 5 with a more negative Volta potential relative to α-Mg phase. The preferential corrosion of Mg41Nd5 is proven by in-situ observation and SEM. The solid solution treatment of Mg-3Nd-1Li-0.2Zn alloy led to a shift in corrosion type from pitting corrosion to uniform corrosion under long-term exposure. [ABSTRACT FROM AUTHOR]

The biocorrosion of magnesium in the external physiological environment is still difficult to accurately evaluate the degradation behavior in vivo, particularly, in the microenvironment of the patients with hyperglycemia or diabetes. Thus, we explored the synergistic effects of glucose and protein on the biodegradation of pure magnesium, so as to have a deeper understanding the mechanism of the degradation in vivo. The surface morphology and corrosion product composition of pure magnesium were investigated using SEM, EDS, FTIR, XRD and XPS. The effect of glucose and albumin on the degradation rate of pure magnesium was investigated via electrochemical and immersion tests. The adsorption of glucose and albumin on the sample surface was observed using fluorescence microscopy. The results showed that the presence of 2 g/L glucose changed the micromorphology of corrosion products on the magnesium surface by reacting with metal cations, thus inhibiting the corrosion of pure magnesium. Protein formed a barrier layer to protect the magnesium at early stage of immersion. The chelation reaction between protein and magnesium surface might accelerate the degradation at later stage. There may be a critical glucose (albumin) content. Biodegradation of pure magnesium was inhibited at low concentrations and promoted at high concentrations. The synergistic effect of glucose and protein restrained the adsorption of aggressive chloride ions to a certain extent, and thus inhibited the degradation of pure magnesium considerably. Moreover, XPS results indicated that glucose promoted the adsorption of protein on the sample surface.

Implantable and wearable materials, which are usually used in/on a biological body, are mostly needed with biomimetic self-healing function. To enable repeatable large-wound self-healing and volume/structure recovery, we verified a proof-of-concept approach in this work. We design a polymer hydrogel that combines temperature responsiveness with an intrinsic self-healing ability through host–guest orthogonal self-assembly between two types of poly(N-isopropylacrylamide) (PNIPAM) oligomers. The result is thermosensitive, capable of fast self-repair of microcracks based on reversible host–guest assembly. More importantly, when a large open wound appears, the hydrogel can first close the wound via volume swelling and then completely self-repair the damage in terms of intrinsic self-healing. Meanwhile, its original volume can be easily recovered by subsequent contraction. As demonstrated by the experimental data, such millimeter-level wound self-healing and volume recovery can be repeatedly carried out in response to the short-term cooling stimulus. With low cytotoxicity and good biocompatibility, moreover, this highly intelligent hydrogel is greatly promising for practical large-wound self-healing in wound dressing, electronic skins, wearable biosensors, and humanoid robotics, which can tolerate large-scale human motions.

Micro-arc oxidation (MAO) coating with outstanding adhesion strength to Mg alloys has attracted more and more attention. However, owing to the porous structure, aggressive ions easily invaded the MAO/substrate interface through the through pores, limiting long-term corrosion resistance. Therefore, a dense and biocompatible tantalum oxide (Ta2O5) nanofilm was deposited on MAO coated Mg alloy AZ31 through atomic layer deposition (ALD) technique to seal the micropores and regulate the degradation rate. Surface micrography, chemical compositions and crystallographic structure were characterized using FE-SEM, EDS, XPS and XRD. The corrosion resistance of all samples was evaluated through electrochemical and hydrogen evolution tests. Results revealed that the Ta2O5film mainly existed in the form of amorphousness. Moreover, uniform deposition of Ta2O5film and effective sealing of micropores and microcracks in MAO coating were achieved. The current density (icorr) of the composite coating decreased three orders of magnitude than that of the substrate and MAO coating, improving corrosion resistance. Besides, the formation and corrosion resistance mechanisms of the composite coating were proposed.

Biodegradable magnesium (Mg)-based alloys have aroused great concern owing to their promising characteristics as temporary implants for orthopedic application. But their undesirably rapid corrosion rate under physiological conditions has limited the actual clinical application. This study reports the use of a novel biomimetic polyelectrolyte multilayer template, based on polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) via layer-by-layer (LbL) assembly, to improve the corrosion resistance of the alloy. Surface characterization techniques (field-emission scanning electron microscopy, Fourier transform infrared (FTIR) spectrophotometer and X-ray diffractometer) confirmed the formation of biomineralized Ca–P coating on AZ31 alloy. Both hydrogen evolution and electrochemical corrosion tests demonstrated that the corrosion protection of the polyelectrolyte-induced Ca–P coating on AZ31 alloy. The formation mechanism of biomineralized Ca–P coating was proposed.

Pancreatitis is a common gastrointestinal disorder that causes hospitalization with significant morbidity and mortality. The mechanistic pathophysiology of pancreatitis is complicated, limiting the discovery of pharmacological intervention methods. Here, we show that the administration of ATN-161, an antagonist of Integrin-α5, significantly mitigates the pathological condition of acute pancreatitis induced by caerulein. We find that CK19-positive pancreatic ductal cells align parallel to blood vessels in the pancreas. In the caerulein-induced acute pancreatitis model, the newly emergent CK19-positive cells are highly vascularized, with a significant increase in vascular density and endothelial cell number. Single-cell RNA sequencing analysis shows that ductal and endothelial cells are intimate interacting partners, suggesting the existence of a ductal-endothelial interface in the pancreas. Pancreatitis dramatically reduces the crosstalk in the ductal-endothelial interface but promotes the Spp-1/Integrin-α5 signaling. Blocking this signaling with ATN-161 significantly reduces acinar-to-ductal metaplasia, pathological angiogenesis, and restores other abnormal defects induced by caerulein. Our work reveals the therapeutic potential of ATN-161 as an uncharacterized pharmacological method to alleviate the symptoms of pancreatitis.

In situ formation mechanism of steam Mg–Al layered double hydroxide (Mg–Al–CO3-LDH) coatings on AZ31 and AM30 alloys was compared in presence of NaOH aqueous solution. The microstructure and elemental composition of the obtained coatings were analyzed using SEM, EDS, XRD and FTIR. The corrosion resistance of the coated samples was evaluated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and salt spray test. The results indicated that the addition of NaOH significantly influenced the morphology as well as the thickness of the prepared LDH coating. The effect of different Al–Mn phase contents of AZ31 and AM30 alloy on the growth mechanism of the LDH coatings was discussed. The addition of 0.01 M NaOH promoted the growth of the LDH coating on AZ31 and AM30 alloys. The AM30-NaOH-0.01 sample possessed the most compact and uniform surfaces as well as the maximum thickness. The corrosion current density of the samples was reduced by three orders of magnitude compared to their substrates. It was revealed that the addition of a moderate amount of NaOH in the steam would raise the pH level, which would benefit the dissolution of the aluminum phase and promote the growth of LDH coating.

ABSTRACTRhesus macaque (RM, Macaca mulatta), as an important model animal, commonly suffers from chronic diarrheal disease, challenging the breeding of RMs. Gut microbiomes play key roles in maintaining intestinal health of RMs. However, it is still unclear about more features of gut microbiome as responsible for intestinal health of RMs. In this study, we performed de novo assembly of metagenome-assembled genomes (MAGs) based on fecal metagenomes from chronic diarrheal RMs and asymptomatic individuals. In total of 731 non-redundant MAGs with at least 80% completeness were reconstructed in this study. More than 97% MAGs were novel genomes compared with more than 250,000 reference genomes. MAGs of Campylobacterand Helicobacteraceae from RM guts mainly carried flagella-associated virulence genes and chemotaxis-associated virulence genes, which might mediate motility and adhesion of bacteria. Comparing to MAGs of Campylobacterfrom humans, distributions and functions of these MAGs of Campylobacterfrom RMs exhibited significant differences. Most members of Bacteroidota, Spirochaetota, Helicobacteraceae, Lactobacillaceae and Anaerovibriosignificantly decreased in guts of chronic diarrhea RMs. More than 92% MAGs in this study were not contained in 2,985 MAGs previously reported from other 22 non-human primates (NHPs), expanding the microbial diversity in guts of NHPs. The distributions and functions of gut microbiome were prominently influenced by host phylogeny of NHPs. Our results could help to more clearly understand about the diversity and function of RMs gut microbiome.

Depression is a prevalent mental illness that imposes a substantial public health burden. However, the diverse clinical phenotypes observed in patients make it difficult to realize precise diagnosis. Recently, accumulating preclinical and clinical evidence has suggested that inflammation is involved in the pathophysiology of depression. Herein, a molecular imaging–based strategy was proposed as a means to diagnose depression precisely by specifically visualizing the inflammation status associated with depression. Inflammation-targeting MRI nanoprobes were constructed by attaching an intercellular cell adhesion molecule-1 (ICAM-1)-targeting peptide to biocompatible Fe3O4nanoparticles. Systematic studies demonstrated that the nanoprobes could specifically target inflamed vascular endothelial cells and visualize the spatial distribution of inflammation in the depressed brain in vivo through susceptibility-weighted imaging (SWI), which was further confirmed by histological analysis. Additionally, these inflammatory brain regions identified by nanoprobe-based imaging are consistent with the focal regions closely associated with the symptoms of depression as reported in previous behavioral studies. Overall, this is the first study to directly visualize the distribution of inflammation in the depressed brain in vivo through a molecular imaging strategy, which may not only facilitate insight into the biological mechanism underlying depression but also provide a potential target within the depressed brain for the further development of anti-inflammatory therapies.

Purpose: For the past years, the population of firms in China has increased fast. However, the financial research has always fallen behind the financial practice. Also, the Western financial theory may not be completely consistent with China’s context. In addition, appearing internet technology with big data and its applications to business bring some challenges not only to financial practice but also to the financial literature. Thus, the purpose of this paper is to review historical development of research in corporate finance, discuss the current issues and propose 16 key research topics in China context. Design/methodology/approach: This paper surveys Western classical literature and some important literature by Chinese scholars in the field of corporate finance. On this basis, the authors point out the shortcomings of existing research and opportunities for future research. Findings: The authors propose 16 key research topics in the near future considering the current reforms on economic development strategy, financial and taxation system and SOE’s property right under the institutional background in China. Originality/value: This paper makes a contribution to corporate finance research by exploring frontier topics for future research according to the China context and the global trend. These topics represent the demand from enterprises in China and are challenges for the academic world. It is of practical significance and great theoretical value to implement these studies. It will help the management to solve their financial problems and provide a fundamental basis for constructing the financial management theory with Chinese characteristics.

Glacier tourism is an important type of nature-based tourism with great global potential. However, glacial landscapes and environments are seriously affected by global warming. This study used a scoping review method to explore integrated impacts of climate change on glaciers from the academic literature. All reviewed literature included a wide range of both research and non-research-based data or information. All literature was reviewed by summarizing findings of relevant research. It showed that climate warming has led to rapid melting and retreat of glacier landscapes, which has resulted in a huge impact on economic and social systems. The findings indicated that some glacial landscapes are declining in aesthetics or attractiveness while some landscapes face the prospect of sustained decline or even disappearance. This not only affects glacial cultural appreciation or mountain residents' beliefs, but increases the difficulty in entering and experiencing glaciers. Some points of tourism even face the risk of glacial disaster. Rapid glacial retreat or even disappearance will bring a loss of tourism revenues. At present, it is urgent to anticipate and adapt to these integrated impacts. In short, this study provides a general review of the impacts of climate change on glacial tourism and also some references for the adaptation of future glacial tourism to climate change.

Abstract One of the major obstacles for the clinical use of biodegradable magnesium (Mg)-based materials is their high corrosion rate. Micro-arc oxidation (MAO) coatings on Mg alloys provide mild corrosion protection owing to their porous structure. Hence, in this study a dense Mg(OH) 2 film was fabricated on MAO-coated Mg alloy AZ31 in an alkaline electrolyte containing ethylenediamine tetraacetic acid disodium (EDTA-2Na) to reinforce the protection. Surface morphology, chemical composition and growth process of the MAO/Mg(OH) 2 hybrid coating were examined using field-emission scanning electron microscopy, energy dispersive X-ray spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectrophotometer. Corrosion resistance of the coatings was evaluated via potentiodynamic polarization curves and hydrogen evolution tests. Results manifested that the Mg(OH) 2 coating possesses a porous nano-sized structure and completely seals the micro-pores and micro-cracks of the MAO coating. The intermetallic compound of AlMn phase in the substrate plays a key role in the growth of Mg(OH) 2 film. The current density of Mg(OH) 2 -MAO composite coating decreases three orders of magnitude in comparison with that of bare substrate, indicating excellent corrosion resistance. The Mg(OH) 2 -MAO composite coating is beneficial to the formation of calcium phosphate corrosion products on the surface of Mg alloy AZ31, demonstrating a great promise for orthopaedic applications. [ABSTRACT FROM AUTHOR]

Abstract A SnO 2 -doped calcium phosphate (Ca-P-Sn) coating was constructed on Mg-1Li-1Ca alloy by a hydrothermal process. The fabricated functional coatings were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). A triple-layered structure, which is composed of Ca 3 (PO 4) 2 , (Ca, Mg) 3 (PO 4) 2 , SnO 2 , and MgHPO 4 ·3H 2 O, is evident and leads to the formation of Ca 10 (PO 4) 6 (OH) 2 in Hank's solution. Electrochemical measurements, hydrogen evolution tests and plating counts reveal that the corrosion resistance and antibacterial activity were improved through the coating treatment. The embedded SnO 2 nanoparticles enhanced crystallisation of the coating. The formation and degradation mechanisms of the coating were discussed. [ABSTRACT FROM AUTHOR]

A SnO2-doped dicalcium phosphate coating was prepared on AZ31 alloy by means of hydrothermal deposition. The results showed that the coating possessed a globular morphology with a long lamellar crystalline structure and a thickness of approximately 40 μm. The surface of the coating became smooth with an increase additive amount of the SnO2nanoparticles. The corrosion current density and hydrogen evolution rate of the coating prepared in presence of SnO2were reduced compared to the coating without SnO2and the bare AZ31 substrate, indicating an improvement in the corrosion resistance of the SnO2-doped coating.

Exfoliation on as-extruded Mg-1Li-1Ca magnesium alloy was investigated after an immersion in 3.5 wt% NaCl aqueous solution for 90, 120 and 150 days through optical microscope, digital camera, scanning electron microscope, electrochemical workstation, scanning Kalvin probe, X-ray diffraction and Fourier transform infrared spectroscope. The results demonstrated that exfoliation corrosion occurred on extruded Mg-1Li-1Ca alloy due to elongated microstructure parallel to surface, and delamination of lamellar structure resulted from galvanic effect and wedge effect. Skin layer with fine grains exhibited better corrosion resistance, whereas the interior with coarse grains and the intermetallic compound, Mg 2 Ca particles existing in a fibrous structure, dispersed along grain boundaries and extrusion direction in a line. Furthermore, galvanic effect between Mg 2 Ca particles and their neighboring α-Mg matrix facilitated dissolution of Mg 2 Ca particles and α-Mg matrix; wedge effect was caused by formation of corrosion products. Exfoliation corrosion of extruded Mg-Li-Ca alloys might be a synergic effect of pitting corrosion, filiform corrosion, intergranular corrosion and stress corrosion. Finally, exfoliation corrosion mechanism was proposed. [ABSTRACT FROM AUTHOR]

A polymethyltrimethoxysilane (PMTMS)/hydroxyapatite (HA) hybrid coating was successfully fabricated on a magnesium alloy by hydrothermal treatment and immersion method. The microstructure and composition of the coating were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. The physical properties were investigated using scratch testing. At the same time, the corrosion resistance was evaluated via electrochemical and immersion tests. The results demonstrated that the corrosion resistance of the silane hybrid coating was significantly enhanced compared with the naked magnesium alloy. Especially, the corrosion current density of the PMTMS/HA magnesium alloy was three orders of magnitude lower than that of the bare material.

A micro-arc oxidation (MAO)/zinc stearate (ZnSA) composite coating was fabricated via MAO processing and subsequent sealing with electrodeposition of a superhydrophobic ZnSA. The surface morphologies, chemical composition and corrosion resistance of the coatings were investigated using field-emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction and electrochemical and hydrogen evolution measurements. Results indicated that the MAO coating was efficiently sealed by the following superhydrophobic ZnSA coating. The MAO/ZnSA composite coating significantly enhanced the corrosion resistance of Mg alloy Mg-4Li-1Ca due to its superhydrophobic function. Additionally, corrosion mechanism was suggested and discussed for the composite coating. [ABSTRACT FROM AUTHOR]

Influence of glucose on corrosion of biomedical Mg-1.35Ca alloy was made using hydrogen evolution, pH and electrochemical polarization in isotonic saline solution. The corrosion morphologies, compositions and structures were probed by virtue of SEM, EDS, FTIR, XRD and XPS. Results indicate that the glucose accelerated the corrosion of the alloy. The elemental Ca has no visible effect on the corrosion mechanism of glucose for the Mg-1.35Ca alloy in comparison with pure Mg. In addition, the presence of CO2has beneficial effect against corrosion due to the formation of a layer of carbonatecontaining products.

In vitro degradation is an important approach to screening appropriate biomedical magnesium (Mg) alloys at low cost. However, corrosion products deposited on Mg alloys exert a critical impact on corrosion resistance. There are no acceptable criteria on the evaluation on degradation rate of Mg alloys. Understanding the degradation behavior of Mg alloys in presence of Tris buffer is necessary. An investigation was made to compare the influence of Tris-HCl and Tris on the corrosion behavior of Mg alloy AZ31 in the presence of various anions of simulated body fluids via hydrogen evolution, pH value and electrochemical tests. The results demonstrated that the Tris-HCl buffer resulted in general corrosion due to the inhibition of the formation of corrosion products and thus increased the corrosion rate of the AZ31 alloy. Whereas Tris gave rise to pitting corrosion or general corrosion due to the fact that the hydrolysis of the amino-group of Tris led to an increase in solution pH value, and promoted the formation of corrosion products and thus a significant reduction in corrosion rate. In addition, the corrosion mechanisms in the presence of Tris-HCl and Tris were proposed. Tris-HCl as a buffer prevented the formation of precipitates of HCO 3 − , SO 4 2− , HPO 4 2− and H 2 PO 4 − ions during the corrosion of the AZ31 alloy due to its lower buffering pH value (x.x). Thus, both the hydrogen evolution rate and corrosion current density of the alloy were approximately one order of magnitude higher in presence of Tris-HCl than Tris and Tris-free saline solutions. [ABSTRACT FROM AUTHOR]

Surface functionalization of magnesium (Mg) alloys is desired to obtain the surfaces with both improved corrosion resistance and antibacterial property. A corrosion-resistant and antimicrobial coating was prepared on Mg alloy surface by layer-by-layer (LbL) assembly of chitosan (CHI) and poly-L-glutamic acid (PGA) by electrostatic attraction. The functionalized surfaces of the Mg alloys were characterized by field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy and electrochemical tests. The bactericidal activity of the samples against Staphylococcus aureuswas assessed by the zone of plate-counting method. The obtained coating on the Mg alloy substrates exhibits good corrosion resistance and antibacterial performance.

In this article, the fabrication of an active organic–inorganic one-dimensional photonic crystal structure to offer electrothermal fluorescence switching is described. The film is obtained by spin-coating of liquid crystal elastomers (LCEs) and TiO2nanoparticles alternatively. By utilizing the property of LCEs that can change their size and shape reversibly under external thermal stimulations, the λmaxof the photonic band gap of these films is tuned by voltage through electrothermal conversion. The shifted photonic band gap further changes the matching degree between the photonic band gap of the film and the emission spectrum of organic dye mounting on the film. With rhodamine B as an example, the enhancement factor of its fluorescence emission is controlled by varying the matching degree. Thus, the fluorescence intensity is actively switched by voltage applied on the system, in a fast, adjustable, and reversible manner. The control chain of using the electrothermal stimulus to adjust fluorescence intensity via controlling the photonic band gap is proved by a scanning electron microscope (SEM) and UV–vis reflectance. This mechanism also corresponded to the results from the finite-difference time-domain (FDTD) simulation. The comprehensive usage of photonic crystals and liquid crystal elastomers opened a new possibility for active optical devices.

The physiological environment of the human body is an extremely complex system, containing not only inorganic ions but also organic molecules; thus it is necessary to understand the influences of the different functional groups of three six-carbon small organic molecules (glucose (Glu), vitamin C (Vc), and citric acid (CA)) on the degradation mechanisms of pure magnesium (Mg). Electrochemical polarization and impedance spectroscopy, hydrogen evolution rates, and pH monitoring tests were used to characterize the degradation behaviors of pure Mg in 0.9 ​wt% NaCl and phosphate-buffered saline (PBS) solutions. Using scanning electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, the compositions, phase structures, and morphologies of the degradation products were investigated. Results indicated that Glu enhanced the biodegradation rate of pure Mg in 0.9 ​wt% NaCl solution, whereas Vc and CA slowed down their biodegradation rate. In the PBS solution, both Glu and Vc reduced the biodegradation rate of pure Mg, while CA accelerated its initial biodegradation and retarded its long-term biodegradation. In addition, Raman spectroscopy demonstrated the formation of Mg-(gluconate, l-threonic acid, oxalate, and citrate) on the pure Mg. Plausible biodegradation mechanisms of pure Mg are proposed regarding the influences of Glu, Vc, and CA.

Biocompatible polyelectrolyte multilayers (PEMs) and polysiloxane hybrid coatings were prepared to improve the corrosion resistance of biodegradable Mg alloy AZ31. The PEMs, which contained alternating poly(sodium 4-styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH), were first self-assembled on the surface of the AZ31 alloy substrate via electrostatic interactions, designated as (PAH/PSS)5/AZ31. Then, the (PAH/PSS)5/AZ31 samples were dipped into a methyltrimethoxysilane (MTMS) solution to fabricate the PMTMS films, designated as PMTMS/(PAH/PSS)5/AZ31. The surface morphologies, microstructures and chemical compositions of the films were investigated by FE-SEM, FTIR, XRD and XPS. Potentiodynamic polarization, electrochemical impedance spectroscopy and hydrogen evolution measurements demonstrated that the PMTMS/(PAH/PSS)5/AZ31 composite film significantly enhanced the corrosion resistance of the AZ31 alloy in Hank’s balanced salt solution (HBSS). The PAH and PSS films effectively improved the deposition of Ca-P compounds including Ca3(PO4)2and hydroxyapatite (HA). Moreover, the corrosion mechanism of the composite coating was discussed. These coatings could be an alternative candidate coating for biodegradable Mg alloys.

Rationally and efficiently controlling chemical composition, microstructure, and morphology of carbon nanomaterials plays a crucial role in significantly enhancing their functional properties and expending their applications. In this work, a novel strategy for simultaneously controlling these structural parameters was developed on the base of a multifunctional precursor approach, in which the precursor not only serves as carbon source and structure-directing agent, but also contains two heteroatom doping sites. As exemplified by using pyrrole-terminated ionic liquid surfactant as such precursor, in conjunction with sol–gel chemistry this strategy allows for efficiently producing well-defined hollow carbon spheres with controlled microstructure and chemical compositions. Remarkably, the dual-doping sites in confined silica channels provide an exciting opportunity and flexibility to access various doped carbons through simply anion exchange or altering the used oxidative polymerization agent, especially the multispecies codoped materials by combination of the two doping modes. All the results indicate that the described strategy may open up a new avenue for efficiently synthesizing functional carbon materials with highly controllable capability.

Manipulating the degradation rate of biomedical magnesium alloys poses a challenge. The characteristics of a microarc oxidation (MAO), prepared in phytic acid, and poly(l-lactic acid) (PLLA) composite coating, fabricated on a novel Mg–1Li–1Ca alloy, were studied through field emission scanning electron microscopy (FE-SEM), electron probe X-ray microanalysis (EPMA), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The corrosion behaviors of the samples were evaluated via hydrogen evolution, potentiodynamic polarization and electrochemical impedance spectroscopy in Hanks’ solution. The results indicated that the MAO/PLLA composite coatings significantly enhanced the corrosion resistance of the Mg–1Li–1Ca alloy. MTT and ALP assays using MC3T3 osteoblasts indicated that the MAO/PLLA coatings greatly improved the cytocompatibility, and the morphology of the cells cultured on different samples exhibited good adhesion. Hemolysis tests showed that the composite coatings endowed the Mg–1Li–1Ca alloys with a low hemolysis ratio. The increased solution pH resulting from the corrosion of magnesium could be tailored by the degradation of PLLA. The degradation mechanism of the composite coatings was discussed. The MAO/PLLA composite coating may be appropriate for applications on degradable Mg-based orthopedic implants.

The broad class of explosives includes nitro aromatics as well as challenging aliphatic nitro-organics whose detection is important from counter-terrorism and national security perspectives. Here we report a turn-on fluorescent sensor array based on aggregation-induced emission (AIE) fluorophores as receptors. To achieve a good sensing system with fast response, good sensitivity and low detection limit, three receptors with abundant chemical diversities for target analytes were synthesized. The turn-on response of the individual receptor showed highly variable and cross-reactive analyte-dependent changes in fluorescence. The excellent ability to identify a variety of explosives, especially the challenging aliphatic nitro-organics (2,3-dimethyl-2,3-dinitrobutane (DMNB), 1,3,5-trinitro-1,3,5-triazinane (RDX), cyclotetramethylene tetranitramine (HMX) and entaerythritol tetranitrate (PETN)), was demonstrated in qualitative and quantitative analyses with 100% accuracy. The fluorescence signal amplification in the presence of explosives allows for application of these receptors in a sensor microarray suitable for high-throughput screening. These results suggested that the cross-reactive sensor array based on AIE fluorophores could find a wide range of applications for sensing various analytes or complex mixtures.

A superhydrophobic surface was successfully constructed to modify the layered double hydroxide (LDH) coatings on aluminum alloy using stearic acid. The characteristics of the coatings were investigated using SEM, XRD, FT-IR and XPS. The corrosion resistance of the prepared coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results revealed that the superhydrophobic surface considerably improved the corrosion-resistant performance of the LDH coatings on the aluminum alloy substrate. The formation mechanism of the superhydrophobic surface was proposed.

Anisotropic photonic crystal materials have long been pursued for their broad applications. A novel method for creating chemically patterned inverse opals is proposed here. The patterning technique is based on selective photolysis of a photolabile polymer together with postmodification on released amine groups. The patterning method allows regioselective modification within an inverse opal structure, taking advantage of selective chemical reaction. Moreover, combined with the unique signal self-reporting feature of the photonic crystal, the fabricated structure is capable of various applications, including gradient photonic bandgap and dynamic chemical patterns. The proposed method provides the ability to extend the structural and chemical complexity of the photonic crystal, as well as its potential applications.

The objective of the current study was to examine the correlation between high-resolution manometric and videofluoroscopic measurements of the swallowing function.

Assays for acetylcholinesterase (AChE) with high sensitivity and high selectivity as well as facile manipulation have been urgently required in various fields. In this work, a reaction-based photonic strategy was developed for the efficient assay of AChE activity and inhibition based on the synergetic combination of the specific thiol-maleimide addition reaction with photonic porous structure. It was found that various applications including detection of AChE activity, measurement of the related enzymatic kinetics, and screening of inhibitors could be efficiently implemented using such strategy. Remarkably, the unique photonic nanostructure endows the constructed sensing platform with high sensitivity with a limit of detection (LOD) of 5 mU/mL for AChE activity, high selectivity, and self-reporting signaling. Moreover, the label-free solid film-based sensing approach described here has advantages of facile manipulation and bare-eye readout, compared with conventional liquid-phase methods, exhibiting promising potential in practical application for the AChE assay.

Based on the fascinating properties of polydopamine (PDA), a simple strategy was developed for facilely and efficiently fabricating plasmonic substrate with nanohybrid structure (PDA/Metal NPs/PDA). Because of the good reductive ability of PDA, metal nanoparticles such as Ag, Au, or Ag/Au hybrid particles with the good control of size and distribution on plasmonic substrate could be easily achieved. Also, owing to the exceptional self-adhesive nature, the presynthesized monodisperse metal NPs can be directly adsorbed to the surface to enrich plasmon response. Moreover, by carefully tuning the dopamine immersion time, the formed nanohybrid structure PDA/metal NPs/PDA enabled the distance-dependent MEF phenomenon where the distance could be controlled with a resolution of approximately 1 nm. In particular, the covalent (Michael addition or Schiff-base reaction) binding enabled us an easy but efficient way to immobilize a large diverse fluorophores or biomolecules on plasmonic substrate. All these above properties indicated the promising PDA-based plasmonic substrate for fluorescence enhancement. As a demonstration of the good fluorescence enhancement property, thiol-based dye was used. The ca. 5-fold fluorescence intensity enhancement on the plasmonic substrate with pattern structure clearly proved that PDA-based plasmonic substrate was indeed a good reactive platform for fluorescence enhancement. With the assistance of FDTD, the electromagnetic near-field distributions and the radiative power emitted by fluorophores on the substrate were found to be significantly improved, further helpful for explaining our experimental observations. Finally, the optimal set calculations guided us that based on the careful selection of fluorophore and space distance, a better fluorescence enhancement could be achieved for further optical and biological applications. These performed experiments suggested that the PDA-based fabricating protocol is indeed a powerful strategy for creating plasmon substrate that could find a wide range of applications.

Water-entry signal was important to broadcast the water-entry object. The vector sensor could gain the pressure and particle velocity signal, so the azimuth angle of water-entry signal could be estimated by single vector sensor. The complex sound intensity method was applied in vector signal processing in azimuth estimation. The estimated deviation in different SNR was give out via simulating experiment. The method was used in the experiment on the lake and was proved to be effective.

The water-entry point was the first information collecting point on detecting an object which was dropped into water from air. Single vector sensor could estimate the direction of the water-entry point with its sound field pressure and particle velocity signals. The complex sound intensity method was applied in vector signal processing. The simulating experiment and the practical experiment on the lake were all based on the estimation deviation of the theory on different SNR. By processing the devided signal in time domain with this theory, the water-entry object could be tracing timely.