The Rastall gravity is the modified Einstein general relativity, in which the energy-momentum conservation law is generalized to
T
;
μ
μ
ν
=
λ
R
,
ν
. In this work, we derive the Kerr–Newman-AdS ...(KN-AdS) black hole solutions surrounded by the perfect fluid matter in the Rastall gravity using the Newman–Janis method and Mathematica package. We then discuss the black hole properties surrounded by two kinds of specific perfect fluid matter, the dark energy (
ω
=
-
2
/
3
) and the perfect fluid dark matter (
ω
=
-
1
/
3
). Firstly, the Rastall parameter
κ
λ
could be constrained by the weak energy condition and strong energy condition. Secondly, by analyzing the number of roots in the horizon equation, we get the range of the perfect fluid matter intensity
α
, which depends on the black hole mass
M
and the Rastall parameter
κ
λ
. Thirdly, we study the influence of the perfect fluid dark matter and dark energy on the ergosphere. We find that the perfect fluid dark matter has significant effects on the ergosphere size, while the dark energy has smaller effects. Finally, we find that the perfect fluid matter does not change the singularity of the black hole. Furthermore, we investigate the rotation velocity in the equatorial plane for the KN-AdS black hole with dark energy and perfect fluid dark matter. We propose that the rotation curve diversity in Low Surface Brightness galaxies could be explained in the framework of the Rastall gravity when both the perfect fluid dark matter halo and the baryon disk are taken into account.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Chengjiang Biota is the earliest Phanerozoic soft-bodied fossil assemblage offering the most complete snapshot of Earth's initial diversification, the Cambrian Explosion. Although palaeobiologic ...aspects of this biota are well understood, the precise sedimentary environment inhabited by this biota remains debated. Herein, we examine a non-weathered core from the Yu'anshan Formation including the interval preserving the Chengjiang Biota. Our data indicate that the succession was deposited as part of a delta influenced by storm floods (i.e., produced by upstream river floods resulting from ocean storms). Most Chengjiang animals lived in an oxygen and nutrient-rich delta front environment in which unstable salinity and high sedimentation rates were the main stressors. This unexpected finding allows for sophisticated ecological comparisons with other Burgess Shale-type deposits and emphasizes that the long-held view of Burgess Shale-type faunas as snapshots of stable distal shelf and slope communities needs to be revised based on recent sedimentologic advances.
A high-quality perovskite film with interconnected perovskite grains was obtained by incorporating terephthalic acid (TPA) additive into the perovskite precursor solution. The presence of TPA changed ...the crystallization kinetics of the perovskite film and promoted lateral growth of grains in the vicinity of crystal boundaries. As a result, sheet-shaped perovskite was formed and covered onto the bottom grains, which made some adjacent grains partly merge together to form grains-interconnected perovskite film. Perovskite solar cells (PSCs) with TPA additive exhibited a power conversion efficiency (PCE) of 18.51% with less hysteresis, which is obviously higher than that of pristine cells (15.53%). PSCs without and with TPA additive retain 18 and 51% of the initial PCE value, respectively, aging for 35 days exposed to relative humidity 30% in air without encapsulation. Furthermore, MAPbI3 film with TPA additive shows superior thermal stability to the pristine one under 100 °C baking. The results indicate that the presence of TPA in perovskite film can greatly improve the performance of PSCs as well as their moisture resistance and thermal stability.
Silicon photonics have attracted significant interest because of their potential in integrated photonics components and all-dielectric meta-optics elements. One major challenge is to achieve active ...control via strong photon-photon interactions, i.e. optical nonlinearity, which is intrinsically weak in silicon. To boost the nonlinear response, practical applications rely on resonant structures such as microring resonators or photonic crystals. Nevertheless, their typical footprints are larger than 10 μm. Here, we show that 100 nm silicon nano-resonators exhibit a giant photothermal nonlinearity, yielding 90% reversible and repeatable modulation from linear scattering response at low excitation intensities. The equivalent nonlinear index is five-orders larger compared with bulk, based on Mie resonance enhanced absorption and high-efficiency heating in thermally isolated nanostructures. Furthermore, the nanoscale thermal relaxation time reaches nanosecond. This large and fast nonlinearity leads to potential applications for GHz all-optical control at the nanoscale and super-resolution imaging of silicon.
As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a ...graphene-oxide(GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency(PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer.Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partlyremoved during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.
Dual-ion battery (DIB) composed of graphite cathode and lithium anode is regarded as an advanced secondary battery because of the low cost, high working voltage and environmental friendliness. ...However, DIB operated at high potential (usually ≥ 4.5 V versus Li+/Li) is confronted with severe challenges including electrolyte decomposition on cathode interface, and structural deterioration of graphite accompanying with anions de-/intercalation, hinder its cyclic life. To address those drawbacks and preserve the DIB virtues, a feasible and scalable surface modification is achieved for the commercial graphite cathode of mesocarbon microbead. In/ex-situ studies reveal that, such an interfacial engineering facilitates and reconstructs the formation of chemically stable cathode electrolyte interphase with better flexibility alleviating the decomposition of electrolyte, regulating the anions de-/intercalation behavior in graphite with the retainment of structural integrity and without exerting considerable influence on kinetics of anions diffusion. As a result, the modified mesocarbon microbead exhibits a much-extended cycle life with high capacity retention of 82.3% even after 1000 cycles. This study demonstrates that the interface modification of electrode and coating skeleton play important roles on DIB performance improvement, providing the feasible basis for practical application of DIB owing to the green and scalable coating procedures
A feasible surface coating on graphite cathode of dual-ion battery has been constructed to adjust the features of CEI on graphite with better cycling life. More ordered anions de-/intercalation behavior has also been confirmed through in-situ XRD. Display omitted
The early Cambrian succession at Chengjiang contains the most diverse Cambrian fossil assemblage yet described, and contributes significantly to our understanding of the diversification of metazoans ...in the Cambrian “explosion”. The Cambrian Period occupies a transitional episode of global ocean chemistry, following the oxygenation of the surface ocean and of shallow marine environments during the Ediacaran Period, but prior to the establishment of a predominantly oxygenated deep ocean in the mid-Paleozoic. Despite recent attention, a detailed understanding of the chemical conditions that prevailed in early Cambrian marine settings and the relationship of those conditions to early metazoan ecosystems is still emerging. Here, we report multi-proxy geochemical data from two drill cores through the early Cambrian (Series 2) Yu'anshan Formation of Yunnan, China. Results reveal dynamic water-column chemistry within the succession, which progressively shifted from euxinic to oxic conditions during deposition of the Yu'anshan Formation. The Chengjiang biota occurs in strata that appear to have been deposited under an oxygen-depleted water column that may have supported denitrification, as in modern oxygen-minimum zones. The oxygenated benthic environments in which the Chengjiang biota thrived were proximal to, but sharply separated from, the open ocean by a persistent anoxic water mass that occupied a portion of the outer shelf. Oxygen depletion in the lower water column developed dynamically in response to nutrient availability and possibly at lower thresholds of productivity due to lower atmospheric oxygen concentrations in Cambrian. These findings suggest that the frequent development of oxygen-limiting conditions in continental margin settings provided an environmental barrier that may have affected biogeographic, ecological and evolutionary development of early metazoan communities.
•Chengjiang drill core geochemistry reveals dynamic water column redox.•The Chengjiang biota was preserved under oxygen-minimum zone-like conditions.•Persistent outer shelf anoxia separated the Chengjiang biota from the open ocean.•OMZs developed at lower thresholds of productivity in the low-oxygen Cambrian world.•OMZ-like conditions may have affected the stability of early metazoan habitats.
One biosynthetic gene cluster (BGC) usually governs the biosynthesis of a series of compounds exhibiting either the same or similar molecular scaffolds. Reported here is a multiplex activation ...strategy to awaken a cryptic BGC associated with tetracycline polyketides, resulting in the discovery of compounds having different core structures. By constitutively expressing a positive regulator gene in tandem mode, a single BGC directed the biosynthesis of eight aromatic polyketides with two types of frameworks, two pentacyclic isomers and six glycosylated tetracyclines. The proposed biosynthetic pathway, based on systematic gene inactivation and identification of intermediates, employs two sets of tailoring enzymes with a branching point from the same intermediate. These findings not only provide new insights into the role of tailoring enzymes in the diversification of polyketides, but also highlight a reliable strategy for genome mining of natural products.
Breaking the silence: A silent gene cluster was engaged by the expression of a positive regulator gene in tandem mode, directing the biosynthesis of eight aromatic polyketides. These polyketides comprise two different frameworks, two pentacyclic isomers (1 and 2) and six glycosylated tetracyclines (3–8), which are proposed to arise from divergent pathways originating from a common intermediate.
Background
This is a sub‐analysis of the Personalized Antithrombotic Therapy for Coronary Heart Disease after PCI (PATH‐PCI) trial in China to explore the relationship between smoking and outcomes ...following personalized antiplatelet therapy (PAT) in chronic coronary syndrome (CCS) patients undergoing percutaneous coronary intervention (PCI).
Methods
As a single‐center, prospective, randomized controlled and open‐label trial, the PATH‐PCI trial randomized CCS patients undergoing PCI into standard group or personalized group guided by a novel platelet function test (PFT), from December 2016 to February 2018. All patients were divided into smokers and nonsmokers according to their smoking status. Subsequently, we underwent a 180‐day follow‐up evaluation. The primary endpoint was the net adverse clinical events (NACE).
Results
Regardless of smoking status, in the incidence of NACE, there was a reduction with PAT but that the reductions are not statistically significant. In the incidence of bleeding events, we found no statistically significant difference between two groups (smokers: 2.0% vs. 1.4%, HR = 1.455, 95% confidence interval CI: 0.595−3.559, p = .412; nonsmokers: 2.2% vs. 1.8%, HR = 1.228, 95% CI: 0.530−2.842, p = .632). In smokers, PAT reduced major adverse cardiac and cerebrovascular events (MACCE) by 48.7% (3.0% vs. 5.9%, HR = 0.513, 95% CI: 0.290−0.908, p = .022), compared with standard antiplatelet therapy (SAT). PAT also reduced the major adverse cardiovascular events (MACE) but there was no statistically difference in the reductions (p > .05). In nonsmokers, PAT reduced MACCE and MACE by 51.5% (3.3% vs. 6.7%, HR = 0.485, 95% CI: 0.277−0.849, p = .011) and 63.5% (1.8% vs. 4.9%, HR = 0.365, 95% CI: 0.178−0.752, p = .006), respectively. When testing p‐values for interaction, we found there was no significant interaction of smoking status with treatment effects of PAT (pint‐NACE = .184, pint‐bleeding = .660).
Conclusion
Regardless of smoking, PAT reduced the MACE and MACCE, with no significant difference in bleeding. This suggests that PAT was an recommendable regimen to CCS patients after PCI, taking into consideration both ischemic and bleeding risk.
PL‐12 is a new platelet function analyzer testing the platelet maximum aggregation rate. The Personalized Antithrombotic Therapy for Coronary Heart Disease after PCI trial established that personalized antiplatelet therapy (PAT) guided by PL‐12 greatly improved the prognosis of chronic coronary syndrome (CCS) patients undergoing percutaneous coronary intervention. We explored the efficacy and safety of PAT in CCS patients under different smoking status.
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