Abstract
At present, 19 double neutron star (DNS) systems are detected by radio timing and two merging DNS systems are detected by kilohertz gravitational waves. Because of selection effects, none of ...them has an orbital period
P
b
in the range of a few tens of minutes. In this paper we consider a multimessenger strategy proposed by Kyutoku et al., jointly using the Laser Interferometer Space Antenna and the Square Kilometre Array to detect and study Galactic pulsar-neutron star (PSR-NS) systems with
P
b
∼ 10–100 minutes. We assume that we will detect PSR-NS systems by this strategy. We use standard pulsar-timing software to simulate times of arrival of pulse signals from these binary pulsars. We obtain the precision of timing parameters of short-orbital-period PSR-NS systems with orbital period
P
b
∈ (8, 120) minutes. We use the simulated uncertainty of the orbital decay,
P
̇
b
, to predict future tests for a variety of alternative theories of gravity. We show quantitatively that highly relativistic PSR-NS systems will significantly improve the constraint on parameters of specific gravity theories in the strong field regime. We also investigate the orbital periastron advance caused by the Lense−Thirring effect in a PSR-NS system with
P
b
= 8 minutes, and show that the Lense−Thirring effect will be detectable to a good precision.
We propose a six-dimensional light-front Wigner distribution for the complete description of partonic structures of a hadron such as pion and proton, taking advantage of the recently proposed ...light-front variable z˜ by Miller and Brodsky. Quantities derived from the Wigner distribution contain the most general information of partonic structures, including also new quantities correlating longitudinal coordinate with transverse momenta or transverse coordinates, together with spins. The new Wigner distribution can be viewed as a relativistic version of the original Wigner distribution in hadron physics and an extension of widely utilized five-dimensional light-front Wigner distribution.
Graphene family nanomaterials (GFNs) have attracted significant attention due to their unique characteristics and applications in the fields of biomedicine and nanotechnology. However, previous ...studies highlighted the in vitro and in vivo toxicity of GFNs with size and oxidation state differences are still elusive. Therefore, we prepared graphene (G) and graphene oxide (GO) of three different sizes (S-small, M-medium, and L-large), and characterized them using multiple surface-sensitive analytical techniques. In vitro assays using HEK 293T cells revealed that the small and large sizes of G and GO significantly reduced the cell viability and increased DNA damage, accompanying with activated reactive oxygen species (ROS) generation and induced various expressions of associated critical genetic markers. Moreover, the bacterial assays highlighted that G and GO caused strong acute toxicity on Tox2 bacteria. Effects of G were higher than GO and showed size dependent effect: L > M > S, while the medium size of GO induced mild genetic toxicity on RecA bacteria. In vivo assays revealed that exposure to G and GO caused the developmental toxicity, induced ROS generation, and activated related pathways (specifically GO) in zebrafish. Taken together, G showed stronger ability to decrease the survival rate and induce the acute toxicity, while GO showed obvious toxicity in terms of DNA damages, ROS generation, and abnormal gene expressions. Our findings highlighted that G and GO differentially induced toxicity based on their varying physical characteristics, especially sizes and oxidation state, and exposure concentrations and sensitivity of the employed in vitro and in vivo models. In short, this study provided deep insights on the negative effects of GFNs exposure.
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•The toxicity of G and GO was differed based on sizes, oxidation state, exposure concentrations, and sensitivity of the experimental model used.•GFNs reduced cell viability in the following order of size; S > L > M with stronger impact of G than GO.•Toxic potential of GO > G in terms of DNA damages, ROS generation and varying gene expression in vitro and in vivo.•G induced acute toxicity on Tox2 bacteria with size-dependent manner: L>M>S, and M-GO showed obvious genetic toxicity on RecA bacteria.
We reexamine the shapes of the strange quark parton distribution functions (PDFs) of the proton by means of QCD analysis of HERA I + II e± p deep inelastic scattering cross section measurement at ...DESY and inclusive gauge boson production and W boson production associated with a charm quark from the LHC at CERN. We find that there is an overall agreement on the strange quark distributions obtained from CMS W + charm and ATLAS W / Z data at the parton momentum fraction range x ≲ 10−2. Meanwhile, there is also a strong tension between these data toward large x . We find that this tension fades away if the ATLAS measurement of W/Z production is analyzed together with the ATLAS W + charm data. The W/Z and W + charm data both from ATLAS and CMS experiments agree that the proton strangeness is enhanced toward small momentum fraction x and is smoothly suppressed at large x . Furthermore, a strong x dependence of the strange-to-nonstrange parton ratio Rs (x, Q2) is observed.
Electrical machines are the hearts of many appliances, industrial equipment and systems. In the context of global sustainability, they must fulfill various requirements, not only physically and ...technologically but also environmentally. Therefore, their design optimization process becomes more and more complex as more engineering disciplines/domains and constraints are involved, such as electromagnetics, structural mechanics and heat transfer. This paper aims to present a review of the design optimization methods for electrical machines, including design analysis methods and models, optimization models, algorithms and methods/strategies. Several efficient optimization methods/strategies are highlighted with comments, including surrogate-model based and multi-level optimization methods. In addition, two promising and challenging topics in both academic and industrial communities are discussed, and two novel optimization methods are introduced for advanced design optimization of electrical machines. First, a system-level design optimization method is introduced for the development of advanced electric drive systems. Second, a robust design optimization method based on the design for six-sigma technique is introduced for high-quality manufacturing of electrical machines in production. Meanwhile, a proposal is presented for the development of a robust design optimization service based on industrial big data and cloud computing services. Finally, five future directions are proposed, including smart design optimization method for future intelligent design and production of electrical machines.
Di-(2-ethylhexyl) phthalate (DEHP) has the potential to disrupt the thyroid endocrine system, but the underlying mechanism is unknown. In this study, zebrafish (Danio rerio) embryos were exposed to ...different concentrations of DEHP (0, 40, 100, 200, 400 μg/L) from 2 to 168 hours post fertilization (hpf). Thyroid hormones (THs) levels and transcriptional profiling of key genes related to hypothalamus-pituitary-thyroid (HPT) axis were examined. The result of whole-body thyroxine (T4) and triiodothyronine (T3) indicated that the thyroid hormone homeostasis was disrupted by DEHP in the zebrafish larvae. After exposure to DEHP, the mRNA expressions of thyroid stimulating hormone (tshβ) and corticotrophin releasing hormone (crh) genes were increased in a concentration dependent manner, respectively. The expression level of genes involved in thyroid development (nkx2.1 and pax8) and thyroid synthesis (sodium/iodide symporter, nis, thyroglobulin, tg) were also measured. The transcripts of nkx2.1 and tg were significantly increased after DEHP exposure, while those of nis and pax8 had no significant change. Down-regulation of uridinediphosphate-glucuronosyl-transferase (ugt1ab) and up-regulation of thyronine deiodinase (dio2) might change the THs levels. In addition, the transcript of transthyretin (ttr) was up-regulated, while the mRNA levels of thyroid hormone receptors (trα and trβ) remained unchanged. All the results demonstrated that exposure to DEHP altered the whole-body thyroid hormones in the zebrafish larvae and changed the expression profiling of key genes related to HPT axis, proving that DEHP induced the thyroid endocrine toxicity and potentially affected the synthesis, regulation and action of thyroid hormones.
Straw mulching is a typical soil and water conservation measure for slope farms, and it plays an important role in preventing soil erosion. The objective of this study was to quantify the effects of ...the length and coverage of wheat straw on infiltration, runoff and soil loss. In this study, an indoor simulated rainfall experiment was used to study the characteristics of infiltration, runoff and sediment yield under different straw lengths and coverage when the rainfall intensity was 90 mm h−1. The results show that the straw mulch contributes more to the effect of infiltration, runoff and sediment yield than straw length. Increasing the straw coverage increases the average infiltration rate and reduces the cumulative runoff and sediment yield. An increase in straw length, however, reduces the average infiltration rate of the slope and increases the cumulative runoff and sediment yield. The benefits of straw mulch in increasing average infiltration and reducing runoff and sediment yield are consistent with the law of diminishing marginal returns. The marginal benefit of straw is optimal when the straw cover is 3.5 t·hm−2. The sum of straw mulch and length multiplied by cover divided by length has a power function relationship with slope infiltration, while runoff and sediment yield have a power function relationship with its reciprocal. The average infiltration rate of the slope surface is significantly linearly related to the cumulative sediment yield. The simulation accuracy of the Horton model is higher than that of the Kostiakov model. In this study, when the straw length was 3–5 cm and the mulch rate was 4.5 t·hm−2, the average slope infiltration was highest, and the runoff and sediment yield were lowest. Wheat straw surface mulch, when applied as an effective measure for controlling soil erosion and maintaining soil and water resources on sloped fields, can effectively increase infiltration and reduce runoff and sediment yield; wheat mulch is thus critical for the sustainable development of agriculture and ecology on sloping land.
An increase in straw length, reduces the infiltration rate and increases the runoff and sediment yield.
The benefits of straw mulch are consistent with the law of diminishing marginal returns.
The sum of straw mulch and length multiplied by cover divided by length has a power function relationship with slope infiltration, while slope runoff and sand production have a power function relationship with its reciprocal.
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