Search

Cosmological observations, e.g., cosmic microwave background, have precisely measured the spectrum of primordial curvature perturbation on larger scales, but smaller scales are still poorly constrained. Since primordial black holes (PBHs) could form in the very early Universe through the gravitational collapse of primordial density perturbations, constraints on the PBH could encode much information on primordial fluctuations. In this work, we first derive a simple formula for the lensing effect to apply PBH constraints with the monochromatic mass distribution to an extended mass distribution. Then, we investigate the latest fast radio burst observations with this relationship to constrain two kinds of primordial curvature perturbation models on small scales. This suggests that, from the null search result of lensed fast radio bursts in currently available observations, the amplitude of primordial curvature perturbation should be less than 8 × 10−2 at the scale region of 105–106 Mpc−1. This corresponds to an interesting mass range relating to binary black holes detected by LIGO–Virgo–KAGRA and future Einstein Telescope or Cosmic Explorer. [ABSTRACT FROM AUTHOR]

Herein, we report a facile and efficient preparation of prism[6]arene (P6) using the condensation of 2,6-diethoxy-1,5-bis(methoxymethyl)naphthalene catalyzed by p-toluenesulfonic acid. Meanwhile, the host–guest property is investigated using 1-adamantane ammonium tetrakis[3,5-bis(trifluoromethyl)-phenyl]borate (G) as the guest. Interestingly, the complexation between P6 and G showed both Cl−/Ag+ and pH responsiveness. [ABSTRACT FROM AUTHOR]

Since the first gravitational wave (GW) event from binary black hole (BBH) was detected by LIGO-Virgo, GWs have become a useful probe on astrophysics and cosmology. If compact dark matter (DM) objects e.g. primordial black holes, contribute a significant fraction of DM at wide mass range, they will cause microlensing in the GW signals with long wavelengths that are distinct from the lensing effects of electromagnetic signals from astrophysical objects. In this paper, we apply the lensing effect of GW from BBH to derive constraints on the abundance of compact DM for the Cosmic Explorer, a third-generation ground-based GW detector. We first consider two channels of formation of BBH that contribute to low- and high-redshift GW sources, including the astrophysical origin BBH scenario, and the primordial origin BBH scenario. Secondly, comparing with the method of optical depth, we use the Bayesian analysis to derive constraints on the abundance of compact DM with different mass function of lens taken into consideration. For a null search with 1000 detected GW events of BBH, we find that the abundance of compact DM could be constrained to |$\lesssim 0.1\,\mathrm{ per}\,\mathrm{ cent}$| in the mass range |$\ge 500\, {\rm M}_{\odot }$| at 68 per cent confidence level. In addition, if a GW event lensed by a compact DM object with |$M_{\rm l}\in [100\, {\rm M}_{\odot },300\, {\rm M}_{\odot }]$| is detected in 100 detected GW events of BBH, we can derive that the estimation of the abundance of compact DM is from |$2.3$| to |$25.2$| per cent in this mass range with the Bayesian analysis. [ABSTRACT FROM AUTHOR]

A new efficient magnetic solid-phase extractant based on a surface-modified magnetic mesoporous silica microsphere referred as MMSM-PEI was synthesised and used for the enrichment and isolation of copper ions (Cu2+) in preserved eggs. The physicochemical properties and morphology of MMSM-PEI were characterized by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), vibration sample magnetometry (VSM), scanning electron microscopy (SEM) and thermos-gravimetric analyses (TGA). The concentrations of trace Cu2+ in the preserved egg were determined by flame atomic absorption spectroscopy (FAAS). The effects of important parameters were examined. The most suitable pH values and temperature for adsorbing Cu2+ were 6.5 and 25 °C, respectively. According to the determination of Cu2+ in egg white, egg yolk and the outer coating mixture (TOCM) of preserved eggs, the spiked recovery and RSD were 94.1–103.8% and 0.96–4.35%, respectively. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.14 mg/kg and 0.46 mg/kg, respectively. The developed method improved the sensitivity and accuracy of FAAS for the determination of Cu2+ and it could be applied to the determination of trace Cu2+ in real samples. [ABSTRACT FROM AUTHOR]

Strong gravitational lensing effect is a powerful tool to probe cosmological models and gravity theories. Recently, the time-delay cosmography from strong lensing and the stellar kinematics of the deflector, which encode the Hubble constant and the post-Newtonian parameter via two distance ratios reflecting the lensing mass and dynamical mass, respectively, have been proposed to investigate these two parameters simultaneously. Among strong-lensing systems with different sources, strongly lensed fast radio bursts (FRBs) have been proposed as precision probes of the universe since the time-delay ∼ 10 d between images could be measured extremely precisely because of their short duration of a few milliseconds. In this work, we investigate the ability of strongly lensed FRBs on simultaneously estimating these two parameters via simulations. Take the expected FRB detection rate of upcoming facilities and lensing probability into consideration, it is likely to accumulate 10 lensed FRBs in several years and we find that H 0 could be determined to an |$\sim 1.5{{\,\rm per\,cent}}$| precision and γPPN could be constrained to an |$\sim 8.7{{\,\rm per\,cent}}$| precision simultaneously from them. These simultaneous estimations will be helpful for properly reflecting the possible correlation between these two fundamental parameters. [ABSTRACT FROM AUTHOR]

Primordial black holes (PBHs) has been considered to form a part of dark matter for a long time but the possibility has been poorly constrained over a wide mass range, including the stellar mass range (⁠|$1{-}100\ {\rm M}_{\odot }$|⁠). However, due to the discovery of merger events of black hole binaries by LIGO-Virgo gravitational wave observatories, the interest for PBHs in the stellar mass window has been aroused again. Fast radio bursts (FRBs) are bright radio transients with millisecond duration and very high all-sky occurrence rate. Lensing effect of these bursts has been proposed as one of the optimal probes for constraining the abundance of PBHs in the stellar mass range. In this paper, we first investigate constraints on the abundance of PBHs from the latest 593 FRB observations for both the monochromatic mass distribution and three other popular extended mass distributions related to different formation mechanisms of PBHs. It is found that constraints from currently public FRB observations are relatively weaker than those from existing gravitational wave detections. Furthermore, we forecast constraining power of future FRB observations on the abundance of PBHs with different mass distributions of PBHs and different redshift distributions of FRBs taken into account. Finally, We find that constraints of parameter space on extended mass distributions from ∼105 FRBs with |$\overline{\Delta t}\le 1 ~\rm ms$| would be comparable with what can be constrained from gravitational wave events. It is foreseen that upcoming complementary multimessenger observations will yield considerable constraints on the possibilities of PBHs in this intriguing mass window. [ABSTRACT FROM AUTHOR]

The possibility that primordial black holes (PBHs) form some part of dark matter has been considered for a long time but poorly constrained over a wide mass range. Fast radio bursts (FRBs) are bright radio transients with millisecond duration. Their lensing effect has been proposed to be one of the cleanest probes for constraining the presence of PBHs in the stellar-mass window. In this paper, we first apply the normalized cross-correlation algorithm to search and identify candidates for lensed FRBs in the latest public FRB observations, i.e., 593 FRBs, which mainly consist of the first Canadian Hydrogen Intensity Mapping Experiment FRB catalog, and then derive constraints on the abundance of PBHs from the null search result of the lensing signature. For a monochromatic mass distribution, the fraction of dark matter made up of PBHs could be constrained to ≤87% for ≥500 M ⊙ at the 95% confidence level by assuming signal-to-noise ratios dependent on the flux ratio threshold for each FRB and that apparently one-off events are intrinsic single bursts. This result would be improved by a factor of 3 when a conventional constant flux ratio threshold is considered. Moreover, we derive constraints on PBHs with a log-normal mass function naturally predicted by some popular inflation models and often investigated with gravitational-wave detections. We find that, in this mass distribution scenario, the constraint from the current public FRB observations is relatively weaker than the one from gravitational-wave detections. It is foreseen that upcoming complementary multimessenger observations will yield considerable constraints on the possibilities of PBHs in this intriguing mass window. [ABSTRACT FROM AUTHOR]

Padé cosmography has been widely used to probe the cosmic evolution and to investigate the nature of dark energy. In this paper, we find that the Padé approximant can describe the cosmic evolution better than the standard cosmography, and if the luminosity distance d L (z) described by the Padé approximant is used to reconstruct the dark energy equation of state w (z) , then the reconstructed w (z) will approach a constant, i.e. 1 / 3 or 0, when the redshift is very high. This result is general since it is independent of the coefficients in the Padé approximant and the value of the present dimensionless matter density parameter. This intrinsic character will bias the w (z) reconstruction and lead to misconception of the property of dark energy. Therefore, one must exercise caution in investigating the property of dark energy from Padé cosmography when the high redshift data, i.e. z > 2 , are included. [ABSTRACT FROM AUTHOR]

On the basis of the theoretical predication that a small fraction of fast radio bursts (FRBs) might be associated with gravitational waves (GWs), Wei et al. proposed FRB/GW association systems, i.e., the joint measurement of dispersion measures (DM) of FRBs and luminosity distances DL of GWs (the combination DM · DL), as an effective complementary cosmic probe, which has the advantage of being independent of the Hubble constant H0. However, it is still unclear what the progenitor of FRBs is and whether a GW signal should be associated with them. In this paper, we propose that, with the fundamental assumption that luminosity distance is a monotonously increasing function of redshift, this DM · DL method could be further extended to the combination of DM measurements of localized FRBs and independent DL measurements of type Ia supernovae (SNe Ia) at similar redshifts. In practice, this extended combination, i.e., DM · DL as a function of redshift from independent DM and DL measurements, may be more applicable. In addition, we investigated the constraining power of this extended combination on dark energy evolution. It was obtained that, in the frame of the Chevalier–Polarski–Linder parameterization, the power of constraints on the dark energy equation of state from only ∼500 DM · DL combinations is even stronger than the one from the currently available 1048 Pantheon SNe Ia. More interestingly, we also found that, compared with the popular luminosity distance–redshift relation alone, the combination DM · DL, as a function of redshift, is more effective in constraining the parameter characterizing the evolution of dark energy. This benefit, along with rapid progress in the upcoming FRB observations, can be of great importance for studying the nature of dark energy. [ABSTRACT FROM AUTHOR]

It has been shown that time delay of strong gravitational lensing is not only an effective cosmological probe to constrain the Hubble constant, the matter density, and the curvature of the universe but also useful for breaking the degeneracy of the dark energy equation of state and thus provide complementarity with other popular probes, such as Type Ia supernovae, baryon acoustic oscillations, and cosmic microwave background radiation. Interestingly, compared to traditional strong lensing systems where quasars act as sources, strongly lensed gravitational waves (GWs) from compact binary coalescence and their electromagnetic (EM) counterpart systems have been recently proposed to be more powerful for studying cosmology since GWs and their EM counterparts are transients. Short durations of GWs and their EM counterparts are very advantageous to time delay measurement and lens profile modelling. Here, in the framework of Chevalier–Polarski–Linder parametrization, we investigate improvement of constraining power on the dark energy equation of state due to including time delay measurements of strong lensed GW systems. It is suggested that, on the basis of the third generation ground-based detector, e.g. the Einstein Telescope, adding time delay of only 30 strong lensed GW systems to Type Ia supernovae and cosmic microwave background radiation can improve the dark energy figure of merit by a factor of 2. For the traditional standard siren method where the uncertainties of luminosity distances of GWs are |${\sim }10{{\ \rm per\ cent}}$|⁠ , a few × 104 events are expected to present similar constraints. In the precision cosmology era, this progress is of great significance for studying the nature of dark energy. [ABSTRACT FROM AUTHOR]

Primordial black holes (PBHs) can be both candidates of dark matter and progenitors of binary black holes (BBHs) detected by the LIGO-Virgo-KAGRA collaboration. Since PBHs could form in the very early Universe through the gravitational collapse of primordial density perturbations, the population of BBHs detected by gravitational waves encodes much information on primordial curvature perturbation. In this work, we take a reliable and systematic approach to reconstruct the power spectrum of the primordial curvature perturbation from GWTC-3, under the hierarchical Bayesian inference framework, by accounting for the measurement uncertainties and selection effects. In addition to just considering the single PBH population model, we also report the results considering the multi-population model, i.e., the mixed PBH and astrophysical black hole binaries model. We find that the maximum amplitude of the reconstructed power spectrum of primordial curvature perturbation can be ∼ 2.5 × 10 − 2 at O (10 5) Mp c − 1 scales, which is consistent with the PBH formation scenario from inflation at small scales. [ABSTRACT FROM AUTHOR]

Gamma-ray bursts (GRBs), have been widely used as distance indicators to measure the cosmic expansion and explore the nature of dark energy. A popular method adopted in previous works is to calibrate the luminosity relations which are responsible for distance estimation of GRBs with more primary (low redshift) cosmic distance ladder objects, type Ia supernovae (SNe Ia). Since distances of SNe Ia in all SN Ia samples used to calibrate GRB luminosity relations were usually derived from the global fit in a specific cosmological model, the distance of GRB at a given redshift calibrated with matching SNe Ia was still cosmological-model-dependent. In this paper, we first directly determine the distances of SNe Ia with the Angular Diameter Distances (ADDs) of galaxy clusters without any assumption for the background of the universe, and then calibrate GRB luminosity relations with our cosmology-independent distances of SNe Ia. The results suggest that, compared to the previous original manner where distances of SNe Ia used as calibrators are determined from the global fit in a particular cosmological model, our treatments proposed here yield almost the same calibrations of GRB luminosity relations and the cosmological implications of them do not suffer any circularity. [ABSTRACT FROM AUTHOR]

A generalized scenario, which is used to characterize the attenuated dilution of cold dark matter deviating from the standard case, is proposed for the interaction of cosmological dark sectors. This generalized framework cannot only fully recover the three frequently studied phenomenological parameterizations in the limit of the characteristic parameter α→−1,0 and +1, but also admits a much wider range of cosmological solutions for other values of α. Moreover, some cosmological consequences are examined by placing constraints on this generalized interacting model with current observational data. We find that, for α in the extended range of [−1.0, 1.0], the case in which the energy flow transfers from dark matter to dark energy is slightly favored by observations. [ABSTRACT FROM AUTHOR]

Abstract: We use the newly published 28 observational Hubble parameter data () and current largest SNe Ia samples (Union2.1) to test whether the universe is transparent. Three cosmological-model-independent methods (nearby SNe Ia method, interpolation method and smoothing method) are proposed through comparing opacity-free distance modulus from Hubble parameter data and opacity-dependent distance modulus from SNe Ia. Two parameterizations, and are adopted for the optical depth associated to the cosmic absorption. We find that the results are not sensitive to the methods and parameterizations. Our results support a transparent universe. [Copyright &y& Elsevier]

Low-calorie sweeteners are widely used to replace or reduce sugar in foods and beverages, and the taste and texture of existing sweeteners are far from that of real sugar. The use of sweetness positive aliasing modifiers is an ideal alternative that can reduce the amount of sugar used while maintaining the original sugar taste. However, the currently available sweetness aliasing agents are synthetic compounds, while natural sweetness aliasing agents have not been reported. Studies have shown that there are potential sweetness modifiers in plants with a "Sweetback effect". The sensory activity fractionation of the extract of the fruit of Phyllanthus emblica was performed to locate the key chemical compounds in P. emblica for sweetness and sweetness aftertaste. The chemical structures of the isolated compounds were analyzed by spectroscopic methods such as ESI-MS and NMR (1H NMR, 13C NMR). Fifteen compounds were identified, namely, 2-Furoic acid (1), quercetin (2), p-hydroxybenzaldehyde (3), methyl gallate (4), ethyl 3,4,5-trimethoxybenzoate (5), syringic acid, (6), gallic acid (7), vanillin (8), protocatechuic acid (9), myricetin (10), kaempferol (11), trans-cinnamic acid (12), naringenin (13), oleanolic acid (14), and rutin (15). Sensory analysis of these chemical components showed that 11 of them (1, 2, 3, 4, 5, 6, 8, 12, 13, 14, 15) were compounds with a sweet taste and the other four (7, 9, 10, 11) were compounds with a sweet aftertaste. Experiments on the sweetness regulating properties of sucrose revealed that the sweet aftertaste component in P. emblica has sweetness inverse variant regulator properties and naringenin has sweetness forward variant regulator properties. [ABSTRACT FROM AUTHOR]

To better understand the delicious taste characteristics of Butyriboletus roseoflavus, the aqueous extract was separated and combined with sensory analysis. Four novel umami peptides, GSAQA, ISKEK, LPKERLYV, and VENQQLAL were isolated and identified by Gel chromatography, RP-HPLC, and Nano-LC-MS/MS. Umami peptides were synthesized to verify their taste characteristics, and sensory evaluation revealed that they could elicit umami and umami enhancement, among them VENQQLAL performing best. The umami thresholds of those peptides range from 0.20 to 0.60 mg/mL. Moreover, the four peptides possessed the potential to enhance salty and sweet taste. Molecular docking showed that all the peptides were embedded in the ligand-binding domain of the umami receptor T1R1/T1R3, and binding sites Lys155, Asn150, and Thr179 may be important in the interaction of umami peptides with T1R3 subunits. Hydrogen bonding and hydrophobic interactions were the most prominent ligand-receptor interaction forces. [ABSTRACT FROM AUTHOR]

Abstract: In this Letter, by reconstructing the Om diagnostic and the deceleration parameter q from the latest Union2 Type Ia Supernova sample with and without the systematic error along with the baryon acoustic oscillation (BAO) and the cosmic microwave background (CMB), we study the cosmic expanding history, using the Chevallier–Polarski–Linder (CPL) parametrization. We obtain that favor an expansion with a decreasing of the acceleration at . However, once the CMB data is added in the analysis, the cosmic acceleration is found to be still increasing, indicating a tension between low redshift data and high redshift. In order to reduce this tension significantly, two different methods are considered and thus two different subsamples of Union2 are selected. We then find that two different give completely different results on the cosmic expanding history when the systematic error is ignored, with one suggesting a decreasing cosmic acceleration, the other just the opposite, although both of them alone with BAO support that the cosmic acceleration is slowing down. However, once the systematic error is considered, two different subsamples of Union2 along with BAO and CMB all favor an increasing of the present cosmic acceleration. Therefore a clear-cut answer on whether the cosmic acceleration is slowing down calls for more consistent data and more reliable methods to analyze them. [Copyright &y& Elsevier]

The possibility that primordial black holes (PBHs) form a part of dark matter has been considered over a wide mass range from the Planck mass (⁠|$10^{-5}~\rm g$|⁠) to the level of the supermassive black hole in the center of the galaxy. Primordial origin might be one of the most important formation channel of supermassive black holes. We use the non-detection of lensing effect of very long baseline interferometer observations of compact radio sources with extremely high angular resolution as a promising probe to constrain the abundance of intergalactic PBHs in the mass range ∼104–109 M⊙. For a sample of well-measured 543 flat-spectrum compact radio sources, no milli-lensed images are found with angular separations between 1.5 and 50 milli-arcsec. From this null search result, we derive that the fraction of dark matter made up of supermassive PBHs in the mass range ∼106–108 M⊙ is |$\lesssim 1.48{{\ \rm per\, cent}}$| at |$95{{\ \rm per\, cent}}$| confidence level. This constraints would be significantly improved due to the rapid increase of the number of measured compact radio sources. For instance, on the basis of none confirmed milli-lensing candidate in the latest ∼14 000 sources, we derive the abundance of supermassive PBHs and obtain that it is |$\lesssim 0.06{{\ \rm per\, cent}}$| at |$95{{\ \rm per\, cent}}$| confidence level. [ABSTRACT FROM AUTHOR]

Objective To determine the efficacy of micro-needle knife therapy versus placebo (sham microneedle knife) for cervicogenic headache. Method A total of 60 eligible patients with cervicogenic headache were assigned to two groups with 30 cases in each group by using a random number table. Treatment group received micro-needle knife therapy and placebo group received sham micro-needle knife. Results After 4 weeks of intervention, the pain index score was significantly lower in the treatment group (1.27 ± 0.583) than that of the placebo group (3.37 ± 0.765); the cervical range of motion was significantly lower in the treatment group A (1.20 ± 0.407) than that of the placebo group (2.47 ± 0.681); the headache duration was significantly lower in the treatment group (3.33 ± 0.661) than that of the placebo group (5.30 ± 0.988); the headache frequency was significantly lower in the treatment group (1.50 ± 0.682) than that of the placebo group (2.73 ± 0.691), and the differences in the data of the two groups were statistically significant. The duration of headache (3.93 ± 0.739) and frequency of headache (1.96 ± 0.556) were significantly lower in the treatment group than that of the placebo group at follow-up, and the difference was statistically significant (P < 0.05). The occurrence of adverse reactions was not statistically significant in the two groups (P > 0.05) Conclusions Micro-needle knife therapy could effectively improve the pain level of cervicogenic headache patients, reduce the headache duration and headache frequency, and improve the mobility of cervical spine. Acupuncture-related adverse events during treatment were infrequent in both groups and it's safe for cervicogenic headache. [ABSTRACT FROM AUTHOR]

The formation and evolution of the Central Asian Orogenic Belt (CAOB) were closely associated with the opening and closure of the so-called "Paleo-Asian Ocean" (PAO). The subduction of the southern PAO is expected to have resulted in widespread Paleozoic arc magmatism in the southernmost CAOB. However, the precise location and timing of such subduction remain uncertain. The Dunhuang Block (DHB) in the southernmost CAOB is thought to have recorded such subduction. In this contribution, we report the results of the zircon U–Pb ages, Hf isotopes, and whole-rock geochemical data for the Lianghu, Dapokouzi, and Xiaowan plutons in the northeastern DHB, NW China. Zircon U–Pb dating reveals that these plutons formed at ca. 510 Ma (the Middle Cambrian) and may represent the oldest arc-related magmatism in the DHB. Geochemically, the Dapokouzi pluton is characterized by high SiO 2 (70.7–71.2 wt%), Na 2 O (5.11–5.26 wt%), Al 2 O 3 (15.5–15.6 wt%), and Sr (730–733 ppm) contents, high Sr/Y (380–398) ratios, moderate Mg# (49–50) values, low MgO (0.61 wt%), K 2 O (2.00–2.01 wt%) and Y (1.84–1.93 ppm) contents, and weakly positive Eu (1.39–1.44) anomalies, indicating geochemical affinities of adakitic rocks. They have positive ε Hf (t) values (+11.2 to +13.9) close to the depleted mantle line and young two-stage model ages (T DM2 = 571–742 Ma). All the geochemical characteristics show that the Dapokouzi pluton was derived from the remelting of juvenile crust with addition of minor metasomatized mantle-derived materials and a residue phase dominated by garnet-bearing amphibolite. Similarly, the Lianghu and Xiaowan plutons have high SiO 2 (70.2–74.4 wt%) and Al 2 O 3 (12.8–14.3 wt%), low MgO (0.61–1.01 wt%) with Mg# values of 35–43 and K 2 O (0.43–1.55 wt%) contents. Compared to the Dapokouzi pluton, they exhibit low Sr (121–155 ppm) and Y (15.3–23.1 ppm) contents, low Sr/Y (5.25–9.54) ratios and Cr-Ni-Co concentrations, and pronouncedly positive ε Hf (t) values (+11.0 to +14.7), indicating that the magmas originated from the remelting of juvenile lower crust followed by significant fractional crystallization at relatively shallow crustal depths. Data from this and previous studies convincingly suggest the DHB was located in a thickened continental arc setting during the early Paleozoic, probably related to the early subduction of the PAO lithosphere. Crustal thickening, as indicated by the geochemical signature of the Dapokouzi pluton, was most likely associated with the underplating of mantle-derived mafic magmas during the slab subduction. This study therefore highlights that the subduction of the southern PAO might have initiated prior to 510 Ma, possibly dating back to the early Cambrian. Unlabelled Image • Middle Cambrian granites are identified in the northeastern Dunhuang Block. • Granites were formed by partial melting of a thickened juvenile continental arc. • Magmatism was related to the early subduction of the southern Paleo-Asian Ocean. • Subduction of the southernmost Paleo-Asian Ocean likely began in the Early Cambrian. [ABSTRACT FROM AUTHOR]

AbstractTrace elements in tree nut oils may be toxic for humans and catalyze the auto-oxidation of the oils, affecting their stability. These elements have not been comprehensively characterized. In this study, we prepared tree nut oils from tree nuts (camellia, acer truncatum, shiny leaf yellow horn, and pecan seeds, as well as walnuts and Brazil nuts) by cold-pressing and determined As, Cd, Cu, Fe, Mn, Pb, Se, and Zn in these seeds and their oils and residues. Moreover, we investigated the elemental migration from seed to oil. The migration of all measured elements from seed to oil was <2%, where Cu exhibited the lowest migration from 0.09 to 0.31%. Moreover, we studied the effect of preheating (25–150 °C) the seeds upon their elemental migration. The Cu, Fe, Mn, and Zn contents increased with the temperature in all tree nut oils. The migration of toxic As, Cd, and Pb did not significantly differ with temperature, suggesting that temperature does not affect the release of these elements from nuts to oil. [ABSTRACT FROM AUTHOR]

Model-independent estimation of H0 and ΩK can provide clues about the origin of the intractable Hubble constant tension and the current cosmic-curvature crisis. Strongly lensed fast radio bursts (FRBs) have been proposed as precision probes of the universe since the time delay ∼ (10 days) between images could be precisely measured due to short durations ∼ of this kind of bright radio pulses. Here, on the basis of the distance sum rule, we investigate the capacity of model-independently estimating these two parameters from time-delay distances of strongly lensed FRBs and luminosity distances of the upcoming Wide Field InfraRed Survey Telescope (WFIRST) type Ia supernovae observations. Considering the expected FRB detection rate of upcoming facilities, we find that H0 could be determined to a ∼1% precision and ΩK could be constrained to ∼0.1 simultaneously from 10 lensed FRBs. These estimations, which are independent of the energy contents of the universe and validity of Einstein's equation on cosmological scales, will be complementary to popular probes and of great importance for clarifying the current crises of cosmology. [ABSTRACT FROM AUTHOR]

Previous studies of the late Neoproterozoic to early Paleozoic sedimentary strata in the Centralian Superbasins of Australia revealed their sedimentary sources from the local Paterson-Petermann orogen and Musgrave Inliers during the Gondwana assembly, based on the prevailing 700-500 Ma and 1.2-1.0 Ga zircon age populations and Hf isotope affinities of these sedimentary rocks with that of the magmatic suppliers in the Petermann orogen and Musgrave Inliers. Investigations on the Cambrian strata of the Ord basin in northern Australia, however, reveal a provenance affinity which is different from the Australian suppliers. The prevailing 980-930 Ma zircon population with dominant positive epsilon Hf values from the Ord basin Cambrian sediments indicates an Indian Himalaya source which features matching zircon age and Hf signals. Furthermore, the northeastern-directed paleocurrents in the Cambrian coastal marine environments of the Ord basin agree with the possibility of Cambrian detritus travelling along the northeastern Gondwana shoreline from Indian Himalaya to the Australian Ord basin. This work demonstrates that, during the Gondwana assembly, Australian basins not only received local sediments, but also caught detritus travelled for thousand kilometres from Indian Himalaya via longshore currents. [ABSTRACT FROM AUTHOR]

Gamma-ray bursts (GRBs) at high redshifts are expected to be gravitationally lensed by objects of different mass scales. Other than a single recent claim, no lensed GRB has been detected so far by using gamma-ray data only. In this paper, we suggest that multiband afterglow data might be an efficient way to search for lensed GRB events. Using the standard afterglow model, we calculate the characteristics of the lensed afterglow lightcurves under the assumption of two popular analytic lens models: the point-mass and singular isothermal sphere models. In particular, when different lensed images cannot be resolved, their signals would be superimposed together with a given time delay. In this case, the X-ray afterglows are likely to contain several X-ray flares of similar width in linear scale and similar spectrum, and the optical afterglow lightcurve will show re-brightening signatures. Since the lightcurves from the image arriving later would be compressed and deformed in the logarithmic timescale, the larger time delay (i.e., the larger mass of the lens), the easier it is to identify the lensing effect. We analyzed the archival data of optical afterglows and found one potential candidate of the lensed GRB (130831A) with time delay ∼500 s; however, observations of this event in gamma-ray and X-ray bands seem not to support the lensing hypothesis. In the future, with the cooperation of the all-sky monitoring gamma-ray detectors and multiband sky survey projects, the method proposed in this paper would be more efficient in searching for strongly lensed GRBs. [ABSTRACT FROM AUTHOR]

Gamma-ray bursts (GRBs) at high redshifts are expected to be gravitationally lensed by objects of different mass scales. Other than a single recent claim, no lensed GRB has been detected so far by using gamma-ray data only. In this paper, we suggest that multiband afterglow data might be an efficient way to search for lensed GRB events. Using the standard afterglow model, we calculate the characteristics of the lensed afterglow lightcurves under the assumption of two popular analytic lens models: the point-mass and singular isothermal sphere models. In particular, when different lensed images cannot be resolved, their signals would be superimposed together with a given time delay. In this case, the X-ray afterglows are likely to contain several X-ray flares of similar width in linear scale and similar spectrum, and the optical afterglow lightcurve will show re-brightening signatures. Since the lightcurves from the image arriving later would be compressed and deformed in the logarithmic timescale, the larger time delay (i.e., the larger mass of the lens), the easier it is to identify the lensing effect. We analyzed the archival data of optical afterglows and found one potential candidate of the lensed GRB (130831A) with time delay ∼500 s; however, observations of this event in gamma-ray and X-ray bands seem not to support the lensing hypothesis. In the future, with the cooperation of the all-sky monitoring gamma-ray detectors and multiband sky survey projects, the method proposed in this paper would be more efficient in searching for strongly lensed GRBs. [ABSTRACT FROM AUTHOR]

Bamboo shoot is an indispensable vegetable in Southeastern China, so a survey of heavy metals in bamboo shoots is a relevant topic of interest. The present study sought to analyse the content of seven heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) in six bamboo shoot species from Southeastern China. Percentages of 3.8% (Cd) and 8.9% (Pb) of the samples exceeded the maximum limits as established by the Chinese legislation. Further health risk assessment exhibited that the Cd intake contribution of these samples could not be negligible. The hazard index (HI) at average exposure was less than one. The average HI values in moso bamboo shoot were significantly higher than those of other bamboo shoot species. Overall, the results indicated that the intake of bamboo shoots is safe for consumers in Southeastern China. [ABSTRACT FROM AUTHOR]

A SHRIMP U-Pb zircon geochronology study of the tuft at the bottom of the Lower Cambrian Niutitang Formation at Songlin, Zunyi, South China yielded a mean 206Pb/238U age of 51 8±5 Ma. It is significantly younger than the Re-Os ages of 537-542 Ma for the overlying polymetallic Ni-Mo-PGE-rich layer in the basal Niutitang Formation at Songlin, suggesting that the Re-Os ages might represent that of the original magma chamber for the Ni-Mo-PGE-rich layer rather than the formation age of the strata. The intra-basinal stratigraphic correlation also implies that the absolute age of the Chengjiang biota should be younger than 518±5 Ma. Our new result, together with the SHRIMP U-Pb zircon age for the K-bentonite in the Zhongyicun member of the Zhujiaqing Formation at the Meishucun section, .Yunnan Province, provides a temporal constraint for the Lower Cambrian of the Yangtze Platform in South China. [ABSTRACT FROM AUTHOR]

In this work, excellent electrostrictive properties with a giant electrostrain of 0.46% and a large electrostriction coefficient of 0.028 m4/C2 were achieved in Ni/Mn-modified (Bi 0.5 Na 0.5) 0.935 Ba 0.065 TiO 3 ceramics. For high-temperature performance, an interesting finding is that the temperature stability of electrostrain is strongly dependent on the applied electric field strengths, that is, the lower the electric field is, the higher the temperature stability will be. A model of the electric-field-induced phase transition was introduced to find the causes of the different stability behaviors at various electric field strengths. The Ni/Mn-modified sample exhibited a fatigue-free behavior that was insensitive to temperature, which can be related to the reversible field-induced ergodic relaxor-ferroelectric phase transition. In addition, the fine-grained microstructure of the ceramics could also provide a high resistance to field cycling and thus improve the fatigue resistance. The current materials show great potential for actuator applications that require good cycling reliability. In this work, we designed Ni/Mn-modified BNT-based ceramics with a large electrostrain. An interesting finding is that the temperature stability of electrostrain is strongly dependent on the applied electric field strengths, that is, the lower the electric field is, the higher the temperature stability will be. A model of the electric-field-induced phase transition was introduced to find the causes of the different stability behaviors at various electric field strengths. Moreover, the modified material exhibited a temperature independent fatigue-free behavior due to its fine-grained microstructure and the reversible field-induced ergodic relaxor-ferroelectric phase transition. Such behavior renders the material have great potential for actuator applications that require good cycling reliability Image, graphical abstract. [ABSTRACT FROM AUTHOR]

• Ultra-slow rate of growth (ν a ~ 1.4 nm min−1) of porous anodic aluminum oxide (PAAO) films has been achieved. • PAAO films with precisely controllable thickness and excellent regularity have been prepared. • The ν a obtained was four times slower than the previously reported minimum value. • The results should be helpful in expanding the application range of ultrathin PAAO films. Porous anodic aluminum oxide (PAAO) films have attracted widespread attention because they can be used as porous templates for the preparation of various nanomaterials. However, there are still some challenges. For example, although fine control of the thickness of AAO films is generally quite easy to achieve, it is difficult to control the thickness of extremely thin films (e.g. <1 µm). This is important for practical applications where accurate control of film thickness is necessary. In the present work, PAAO films have been prepared in an electrolyte composed of a mixture of ethanol and oxalic acid under 40–50 V (at −20 to 0 °C), attaining a minimum growth rate (ν a) of ~1.4 nm min−1 (at −20 °C). The influence of anodization conditions on ν a , the regularity of structural cells, and the interpore distance has been studied in detail. The results show that ν a can be reduced effectively by using an extremely low anodization temperature. Ultra-thin PAAO films with precisely controlled thicknesses have been fabricated using this approach. [ABSTRACT FROM AUTHOR]

• Partial dissolution of desert sand under alkali activation. • Dissolution of iron ions in HCFA and participation in alkali activation reactions. • GGBS substantially increases the compressive strength of HCFA-based alkali-activated materials. • Low modulus facilitates HCFA dissolution. • Desert sand is well suited to alkali activated materials. In this study, the reaction mechanism of desert sand-high calcium fly ash-based alkali-activated mortar under different influencing factors has been investigated. Different properties of the developed desert sand-high calcium fly ash-based alkali-activated mortar, such as flowability, compressive and flexural resistance, micro-morphological attributes, and reaction mechanism, were studied for alkali admixture (Na 2 O/b), sodium silicate modulus, and ground granulated blast-furnace slag (GGBS) content. The results indicate that too low and too high Na 2 O/b (2%, 10%) and sodium silicate modulus (0.4, 2.0) lead to poor flowability and compressive strength. The compressive strength of the specimens could reach more than 70 MPa for Na 2 O/b and sodium silicate modulus in the range of 5%–8% and 1.0–1.5, respectively. With the increase in GGBS content, the flowability of the fresh paste continued to decrease, whereas the compressive strength increased. Under the effect of alkali activation, the desert sand was partially dissolved, promoting the formation of C(N)-A-S-H gel to some extent. It is also found in this study that the iron ions in the high calcium fly ash partially dissolved and formed a rice-grain iron-rich gel, effectively filling the matrix pores. [ABSTRACT FROM AUTHOR]

The activated carbon supported Mo 2 C and W 2 C were synthesized successfully for hydrotreatment of fatty acids to produce diesel-like hydrocarbons. The carburization temperature, carburization gas as well as metal loading amount were studied. High carburization temperature was feasible for W 2 C/AC, but not for Mo 2 C/AC because it resulted in agglomeration of molybdenum compound and destruction of catalyst. Under hydrotreatment condition (360 °C, H 2 3.0 MPa, 3.0 h) the conversion achieved 96.01% over Mo 2 C/AC prepared at 700 °C and 54.88% over W 2 C/AC prepared at 900 °C respectively. During carburization both flowing nitrogen and hydrogen were proper for formation of W 2 C/AC, while only flowing hydrogen was appropriate for Mo 2 C/AC. The hydrotreatment parameters (reaction temperature and reaction time) were also investigated. The high reaction temperature and long reaction time facilitated the conversion of fatty acids, meanwhile the high reaction temperature simultaneously improved the cracking degree of products. [ABSTRACT FROM AUTHOR]

A novel PtSn/NHSS bimetallic catalyst with N-doped hollow silica spheres as the support was synthesized for the gas-phase hydrogenation of acetic acid to ethanol. Its specific activity was 30% higher than that of PtSn/SiO2 due to the enhanced surface exposure of Pt active sites, induced by the strong interaction between Pt and N. [ABSTRACT FROM AUTHOR]

The Asian continent consists of many continental blocks that assembled during the Phanerozoic, accompanied by widespread granitoids. By compiling a series of digital maps of igneous rocks with associated zircon U-Pb ages and petrological datasets, we illustrate the spatial-temporal evolution of the granitoids, which shed new light on the assembling process of the Asian continent. Neoproterozoic granitoids in the Central China Orogenic System evolved from deformed S-type (1100–900 Ma) to weakly or undeformed I-, and A-type granites (850–700 Ma), displaying a transition from syncollisional to postcollisional environment along the northern margin of the South China Craton (or Block), corresponding to the assembly and breakup of Rodinia, respectively. Phanerozoic igneous rocks mainly occur in the Central Asian Orogenic Belt (CAOB) and the Tethyan orogenic system, and record the closure processes of ocean systems, i.e., the Paleo-Asian Ocean (PAO), the Mongol-Okhotsk Ocean, and the Tethyan Ocean, as well as marginal processes along the west Paleo-Pacific Ocean (PPO). The assembly of the Asian continent can be summarized into five major stages. (1) Initial formation of the Siberian-Mongol collage in the PAO domain and the East Asian continental assemblage in the Proto-Tethyan domain, which is evidenced by voluminous 550–500 Ma magmatic belts in the northern CAOB and 520–400 Ma belts in the Central China Orogenic System, respectively. (2) Formation of the North Asian continent through the amalgamation of the above two collages following the closure of the PAO (310–250 Ma). The closure occurred in a double scissor-like manner, as indicated by a westward younging trend of granitoids along the western segment (western Tianshan) of the southern CAOB and an eastward younging trend of granitoids along the central and eastern segment (the Solonker-Xilamulun suture zone) of the southern CAOB. (3) Formation of the East Asian continent by 230–210 Ma through the collision of continental blocks/terranes with the North Asian continent. The processes are recorded by several large (> 1500 km-long) Triassic magmatic belts that evolved from subduction (250–230 Ma) to collision (230–220 Ma). (4) Formation of the main Asian continent through the collision between the East Asian and Siberia-Europe continents, following the closure of the Mongol-Okhotsk Ocean by 150 Ma. This closure also occurred in a scissor-like fashion, as evidenced by an eastward younging trend of 230–150 Ma collision-related granitoids along the Mongol-Okhotsk Suture. (5) Final formation of the Asian continent by the terminal suturing of the Meso- and Neo-Tethys and the final collision between the Indian-Arabian continent and Eurasia, marked by a large 130–120 Ma magmatic belt and a 70–4 Ma leucogranite belt in the southern Tethyan Orogenic System. Continental assembly in north Asia (the PAO domain) was associated with oblique collision and terrene rotation, characterized by curved magmatic belts/oroclines and involved a large volume (ca. > 50%) of juvenile crust; whereas continental assembly in south Asia (the Tethyan domain) was characterized by direct collision, characterized by straight linear magmatic belts and involved a smaller (< 5%) volume of juvenile crust. [Display omitted] • Digital maps based on big data demonstrate lateral migration and compositional evolution of granitic belts in Asia. • Recognition of five major stages for the assembly of the Asian continent. • The assembly of northern Asia was dominated by accretion, and southern Asia by collision. [ABSTRACT FROM AUTHOR]

We report a sequence of thick, well-preserved basaltic lavas interlayered with shallow marine dolomitic carbonates, mudstones and siltstones of the Zhulongguan Group, in the western segment of the North Qilian orogen, northwest China. Two new zircon SIMS ages show that this sequence formed at ∼600–580 Ma. The mafic volcanics can be subdivided into tholeiitic and alkaline basalts, and have compositions similar to present-day ocean island basalt (OIB) or continental flood basalts. The occurrence, geochemical features and age data suggest that the Zhulongguan basalts originated at a continental rift setting in the latest Neoproterozoic, within the north margin of the Qilian-Qaidam block. This volcanic-sedimentary formation exhibits close affinity to the passive continental margin in southeastern Australia. Our observations favor a link of the Qilian-Qaidam block with SE Australia (also south China) during the breakup of Rodinia, thereby filling a void in existing reconstructions of the region. [ABSTRACT FROM AUTHOR]

The creation of cold dark matter (CCDM) can explain the present accelerating cosmic expansion without appealing to dark energy. In this paper, we investigate the age problem of CCDM models by considering five old high redshift objects (OHROs) (old ratio galaxy 3C 65, old galaxy LBDS 53W069, old galaxy LBDS 53W091, high redshift quasar B1422+231, old quasar APM 08279+5255). Two concrete CCDM models, i.e., the LSS and the LJO, are studied. Using the recent SNIa, BAO and H( z) observational data to constrain the model parameters, we can estimate the cosmic age with the model parameters that are their best fit values. By comparing the estimated cosmic age with the age of OHROs, we find that for the LSS, the ages of five OHROs are less than the cosmic age at the same redshift, while for the LJO, the conclusion depends sensitively on both the value for the age of APM 08279+5255 and the value of H. So, to determine whether the age problem exists for the LJO, we need more precise results on the age of APM 08279+5255 and the value of the present Hubble parameter. [ABSTRACT FROM AUTHOR]

Abstract: The genetic links among rift magmatism, crustal growth and water–rock interaction are an important issue about mass and heat transfer between mantle and crust during supercontinent breakup. A combined study of Hf and O isotopes in zircons from Neoproterozoic granitoids in South China provides evidence for growth and reworking of juvenile and ancient crusts with different styles of water–rock interactions along rift tectonic zones. Two generations of the granitoids show contrasting features in both zircon Hf and O isotope compositions, indicating their distinct petrogenesis. The ∼825 Ma granitoids exhibit negative ε Hf(t) values of −3.4±0.8 to −1.6±0.8 with old model Hf ages of 1.81±0.07 to 1.92±0.10 Ga, and high δ 18O values of 8.7 to 10.4‰. These indicate that the source material of granitoid magmas was derived from melting of Paleoproterozoic basement that has the Hf isotope signature similar to the enriched mantle but experienced chemical weathering process before anatexis. Reworking of ancient crust is demonstrated to occur at ∼825 Ma in the orogenic collapse zone, with overprinting of subsolidus hydrothermal alteration during magma emplacement. In contrast, the 760–750 Ma bimodal intrusives are characterized by positive ε Hf(t) values of 3.5±0.8 to 9.9±0.8 with young model Hf ages of 0.94±0.06 to 1.18±0.06 Ga, and both low and high δ 18O values of 4.2 to 6.2‰ relative to 5.3±0.3‰ for the normal mantle zircon. Prompt reworking of juvenile crust is suggested to occur at ∼750 Ma in the rifted tectonic zone, with occurrence of supersolidus hydrothermal alteration and local low-18O magmatism during supercontinent breakup. Contributions of the depleted mantle to their magma sources are contrasting in the two episodes of magmatism in association with breakup of the supercontinent Rodinia. While the change in melt source from the crust to the mantle keeps pace with the advance from continental rifting to supercontinent breakup, significant transport of both heat and material from the depleted mantle to the continental crust only occurred along the active rifting zone. In either case, the growth and reworking of continental crust are episodically associated with rift magmatism. [Copyright &y& Elsevier]