Based on the new version of the gedanken experiments proposed by Sorce and Wald, we examine the weak cosmic censorship conjecture (WCCC) under the spherically charged infalling matter collision ...process in the static charged Gauss-Bonnet black holes. After considering the null energy condition and assuming the stability condition, we derive the perturbation inequality of the matter source. As a result, we find that the static charged Gauss-Bonnet black holes cannot be overcharged under the second-order approximation of the perturbation when the null energy condition is taken into account, although they can be destroyed in the old version of gedanken experiments. Our result shows that the WCCC holds for the above collision process in the Einstein-Maxwell-Gauss-Bonnet gravity and indicates that WCCC may also be valid in the higher curvature gravitational theories.
In this paper, we use the “complexity equals action” (CA) conjecture to discuss growth rate of the complexity in a charged AdS-Vaidya black hole formed by collapsing an uncharged spherically ...symmetric thin shell of null fluid. Using the approach proposed by Lehner et al., we evaluate the action growth rate and the slope of the complexity of formation. Then, we demonstrate that the behaviors of them are in agreement with the switchback effect for the light shock wave case. Moreover, we show that to obtain an expected property of the complexity, it is also necessary for the CA conjecture to add the particular counterterm on the null boundaries.
Abstract
Triple-negative breast cancer (TNBC), a specific subtype of breast cancer that does not express estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor ...2 (HER-2), has clinical features that include high invasiveness, high metastatic potential, proneness to relapse, and poor prognosis. Because TNBC tumors lack ER, PR, and HER2 expression, they are not sensitive to endocrine therapy or HER2 treatment, and standardized TNBC treatment regimens are still lacking. Therefore, development of new TNBC treatment strategies has become an urgent clinical need. By summarizing existing treatment regimens, therapeutic drugs, and their efficacy for different TNBC subtypes and reviewing some new preclinical studies and targeted treatment regimens for TNBC, this paper aims to provide new ideas for TNBC treatment.
In this paper, based on the new version of the gedanken experiments proposed by Sorce and Wald, we examine the weak cosmic censorship in the process of accreting matter fields for nearly extremal ...static charged black holes in the massive gravitational theories coupled to a Maxwell field. In the investigation, we assume that the black hole is perturbed by some matter fields satisfied null energy condition and ultimately settles down to a static state in the asymptotic future. Moreover, we also treat the cosmological constant, the graviton mass, and the coupling constants as variables, and they can be affected by the physical process. Then, after applying the Noether charge method, we derive the first-order and second-order perturbation inequalities of the perturbation matter fields. As a result, we find that the nearly extremal black hole cannot be destroyed under the second-order approximation of perturbation. This result implies that the weak cosmic censorship conjecture is satisfied in the gravitational theories with massive graviton.
A plasma approach is reported to synthesize carbon cloth supported carbon fiber and oxygen defect‐rich NiCoO/NiCoN hetero‐nanowire co‐integrated hybrid catalyst (P‐NCO/NCN‐CF@CC), which includes the ...advanced features of carbon integration, cation doping, defect/vacancy introduction, and heterostructuring. The P‐NCO/NCN shows a fascinating structure with the periphery composed of NCO and the interior co‐composed of NCO and NCN. Its formation mainly depends on the high reactivity of energetic species of NH, Ha, and Hb formed during the plasma discharge. The P‐NCO/NCN‐CF@CC exhibits the oxygen reduction reaction (ORR) activity comparable to the Pt/C and the oxygen evolution reaction (OER) activity higher than RuO2. When used in the all‐solid‐state zinc‐air batteries, it gives a high maximum power density of 109.8 mW cm−2 with no performance drop observed for >300 cycles. The DFT calculations indicate that the NCO/NCN heterostructuring and oxygen defects in NCO play the important roles in the high ORR/OER activities of the catalyst. They can modulate the electronic structure of the catalyst, lowering the energy barriers of rate determining steps.
The plasma approach is employed to the synthesis of the oxygen defective NiCoO/NiCoN heterostructure with improved ORR/OER activities, which includes the advanced features of carbon integration, cation doping, defect/vacancy introduction, and heterostructuring. The assembled flexible all‐solid‐state zinc‐air batteries exhibit an open circuit voltage of 1.48 V and deliver a maximum power density of 109.8 mW cm−2.
ConspectusHydrogen is an ideal energy carrier and plays a critical role in the future energy transition. Distinct from steam reforming, electrochemical water splitting, especially powered by ...renewables, has been considered as a promising technique for scalable production of high-purity hydrogen with no carbon emission. Its commercialization relies on the reduction of electricity consumption and thus hydrogen cost, calling for highly efficient and cost-effective electrocatalysts with the capability of steadily working at high hydrogen output. This requires the electrocatalysts to feature (1) highly active intrinsic sites, (2) abundant accessible active sites, (3) effective electron and mass transfer, (4) high chemical and structural durability, and (5) low-cost and scalable synthesis. It should be noted that all these requirements should be fulfilled together for a practicable electrocatalyst. Much effort has been devoted to addressing one or a few aspects, especially improving the electrocatalytic activity by electronic modulation of active sites, while few reviews have focused on the synergistic modulation of these aspects together although it is essential for advanced electrochemical water splitting.In this Account, we will present recent innovative strategies with an emphasis on our solutions for synergistically modulating intrinsic active sites, electron transportation, mass transfer, and gas evolution, as well as mechanical and chemical durability, of non-precious-metal electrocatalysts, aiming for cost-effective and highly efficient water splitting. The following approaches for coupling these aspects are summarized for both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER). (1)
. The electronic structure of a catalytic site determines the adsorption/desorption of reactive intermediates and thus intrinsic activity. It can be tuned by heterogeneous doping, strain effect, spin polarization, etc. Coupling these effects to optimize the reaction pathways or target simultaneously the activity and stability would advance electrocatalytic performance. (2)
. The crystallinity, crystalline phase, crystalline facets, crystalline defects, etc. affect both activity and stability. Coupling these effects with electronic modulation would enhance the activity together with stability. (3)
. It will focus on concurrently modulating electronic structure for improving the intrinsic activity and morphology for increasing accessible active sites, especially through single action or processing. The mass transfer and gas evolution properties can also be enhanced by morphological modulation to enable water splitting at large output. (4)
. Electrocatalytic reaction generally consists of a couple of elementary reactions. Each one may need a specific active site. Designing and combining various components targeting every elementary step on a space-limited catalyst surface will balance the intermediates and these steps for accelerating the overall reaction. (5)
Taking all these strategies together into account is necessary to integrate all above essential features into one electrocatalyst for enabling high-output water electrolysis. Beyond the progress made to date, the remaining challenges and opportunities is also discussed. With these insights, hopefully, this Account will shed light on the rational design of practical water-splitting electrocatalysts for the cost-effective and scalable production of hydrogen.
The development of cost‐effective catalysts for oxygen evolution reaction (OER) in acidic media is of paramount importance. This work reports that Sr‐doped solid solution structural ultrafine IrMnO2 ...nanoparticles (NPs) (≈1.56 nm) on the carbon nanotubes (Sr‐IrMnO2/CNTs) are efficient catalysts for the acidic OER. Even with the Ir use dosage 3.5 times lower than that of the commercial IrO2, the Sr‐IrMnO2/CNTs only need an overpotential of 236.0 mV to drive 10.0 mA cm−2 and show outstanding stability for >400.0 h. Its Ir mass activity is 39.6 times higher than that of the IrO2 at 1.53 V. The solid solution and Sr‐doping structure of Sr‐IrMnO2 are the main origin of the high catalytic activity and excellent stability of the Sr‐IrMnO2/CNTs. The density function theory calculations indicate that the solid solution structure can promote strong electronic coupling between Ir and Mn, lowering the energy barrier of the OER rate‐determining step. The Sr‐doping can enhance the stability of Ir against the chemical corrosion and demetallation. Water electrolyzers and proton exchange membrane water electrolyzers assembled with the Sr‐IrMnO2/CNTs show superb performance and excellent durability in the acid media.
Sr‐doped solid solution structural ultrafine IrMnO2 nanoparticles (NPs) on the CNTs (Sr‐IrMnO2/CNTs) are efficient and durable catalysts for the acidic OER. The solid solution structure promotes the s electronic coupling between Ir and Mn, improving their OER activity, while the Sr doping enhances the stability of Sr‐IrMnO2, improving the durability of the Sr‐IrMnO2/CNTs.
A stronger than global mean warming trend is projected over Central Asia in the coming century. Based on the historical simulations and projections under four combined scenarios of the Shared ...Socioeconomic Pathways and the Representative Concentration Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) provided by 15 models from the Sixth Phase of Coupled Model Intercomparison Project (CMIP6), we show a comprehensive picture of the future changes in precipitation over Central Asia under rapid warming and investigate possible mechanisms. At the end of the twenty-first century, robust increase of annual mean precipitation under all the scenarios is found (4.23 2.60 to 7.36 %, 10.52 5.05 to 13.36 %, 14.51 8.11 to 16.91 %, 14.41 9.58 to 21.26 % relative to the present-day for SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5, respectively). The response of precipitation to increasing global mean temperature shows similar spatial patterns for the four scenarios with stronger changes over Tianshan mountain and the northern part of Central Asia. Further analysis reveals a wetting trend in spring and a drying trend in summer in both the north of Central Asia (NCA) and south of Central Asia (SCA). The wetting trend in spring is balanced by the increase of evaporation, while the drying trend in summer is mainly contributed by the decrease of vertical moisture advection. The thermodynamic effects associated with humidity changes contribute to the drying trends in both the two domains, while the dynamic effects favor for the drying trend in NCA and offset the drying trend in SCA. The response of precipitation to increasing temperature results in enhanced seasonalities for SCA and NCA, and an advancing of the first peak from summer to spring in the NCA.
Single‐atom catalysts (SACs) have been at the frontier of research field in catalysis owing to the maximized atomic utilization, unique structures and properties. The atomically dispersed and ...catalytically active metal atoms are necessarily anchored by surrounding atoms. As such, the structure and composition of anchoring sites significantly influence the catalytic performance of SACs even with the same metal element. Significant progress has been made to understand structure–activity relationships at an atomic level, but in‐depth understanding in precisely designing highly efficient SACs for the targeted reactions is still required. In this review, various anchoring sites in SACs are summarized and classified into five different types (doped heteroatoms, defect sites, surface atoms, metal sites, and cavity sites). Then, their impacts on catalytic performance are elucidated for electrochemical reactions based on their distance from the metal center (first coordination shell and beyond). Further, SACs anchored on two typical types of hosts, carbon‐ and metal‐based materials, are highlighted, and the effects of anchoring points on achieving the desirable atomic structure, catalytic performance, and reaction pathways are elaborated. At last, insights and outlook to the SAC field based on current achievements and challenges are presented.
Single‐atom catalysts (SACs) with isolated metal atoms stabilized on various supports by surrounding atoms have emerged as a new frontier. The atomic structure and composition of anchoring sites significantly influence the catalytic performance of SACs. An overview of the correlation between the property of anchoring points and catalytic performance to guide the design of SACs is provided.
Practical electrochemical water splitting requires cost‐effective electrodes capable of steadily working at high output, leading to the challenges for efficient and stable electrodes for the oxygen ...evolution reaction (OER). Herein, by simply using conductive FeS microsheet arrays vertically pre‐grown on iron foam (FeS/IF) as both substrate and source to in situ form vertically aligned NiFe(OH)x nanosheets arrays, a hierarchical electrode with a nano/micro sheet‐on‐sheet structure (NiFe(OH)x/FeS/IF) can be readily achieved to meet the requirements. Such hierarchical electrode architecture with a superhydrophilic surface also allows for prompt gas release even at high output. As a result, NiFe(OH)x/FeS/IF exhibits superior OER activity with an overpotential of 245 mV at 50 mA cm−2 and can steadily output 1000 mA cm−2 at a low overpotential of 332 mV. The water‐alkali electrolyzer using NiFe(OH)x/FeS/IF as the anode can deliver 10 mA cm−2 at 1.50 V and steadily operate at 300 mA cm−2 with a small cell voltage for 70 h. Furthermore, a solar‐driven electrolyzer using the developed electrode demonstrates an exceptionally high solar‐to‐hydrogen efficiency of 18.6%. Such performance together with low‐cost Fe‐based materials and facile mass production suggest the present strategy may open up opportunities for rationally designing hierarchical electrocatalysts for practical water splitting or diverse applications.
A 3D hierarchical NiFe(OH)x/FeS/IF electrode with a nano/micro sheet‐on‐sheet structure exhibits superior oxygen evolution reaction activity and durability with a low overpotential of 261 mV at 100 mA cm−2 and 332 mV at 1000 mA cm−2. The water‐alkali electrolyzer, using it as an anode, achieves stable overall water splitting at 300 mA cm−2 with a small cell voltage.
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