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Enhanced geothermal systems (EGSs) are expected to be one of the most promising methods of supplying energy to meet the world's increasing energy demand. However, little attention has been paid to the influence of the number of production wells on the heat extraction performance of an EGS. A series of numerical simulations is organized in this work with three cases: Case 1 (one production well), Case 2 (two production wells), and Case 3 (three production wells). The results indicate that a slight temperature difference exists among the three simulation cases at the planes X-Y (Z = 0) and Y-Z (X = 0), while Case 1 ensures a greater cooling area, and the more production wells, the smaller the cooling area during the heat extraction in plane X-Z (Y = 0). In addition, the continuous injection of cooling water from the injection well and its arrival at different reference points enable the temperature at each point to declining with a variable amplitude of variation. This work also sets an efficiency (ef) to investigate the temperature variation in the EGS, where Case 1 exhibits a similar variation as Case 2, which is also similar to Case 3. It is hoped that this work will play a guiding role in EGS-related exploration and exploitation. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) holds great potential in cancer therapy by virtue of its high precision, non‐invasiveness and low side effect. However, the hypoxic environment of solid tumor significantly restricts the efficacy of PDT. To improve the hypoxic microenvironment, inhibiting the hypoxia‐inducible factor 1α (HIF‐1α) is a rational approach. However, the related small molecule inhibitors suffer from the issue of poor tumor targeting. Herein, we design a nanophotosensitizer AmPPa NP which can inhibit HIF‐1α and conduct PDT with improved efficacy. AmPPa NP is prepared by first encapsulating a hydrophobic NIR photosensitizer mPPa into a carboxyl‐rich amphiphilic copolymer PSMA‐PEG, and then loading a positively charged HIF‐1α inhibitor acriflavine (ACF) on the surface of nanoparticle via electrostatic interaction. Under 635 nm laser irradiation, mPPa within nanoparticles can not only generate 1O2 for PDT but also emit NIR fluorescence signal for tumor imaging. In addition, such design makes ACF can be selectively released under acidic tumor microenvironment. Compared with mPPa NP without ACF loading, AmPPa NP can effectively inhibit HIF‐1α and shows improved PDT efficacy both in vitro and in vivo. This study thus provides a nanotheranostic platform for NIR fluorescence imaging‐guided enhanced PDT. [ABSTRACT FROM AUTHOR]

This document is a corrigendum for an article titled "The number of production wells affects the heat extraction performance of an enhanced geothermal system: insights from engineering-scale 3D THM coupling numerical simulations." The corrigendum acknowledges an error in the funding statement of the original article, where the financial support of the China Three Gorges Corporation was omitted. The correct funding statement is provided in the corrigendum. The authors apologize for the error and state that it does not impact the scientific conclusions of the article. The corrigendum also includes information about the publication details and the authors of the original article. [Extracted from the article]

Sodium-ion hybrid capacitor (SIHC) is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities, natural abundance, and low cost. However, overcoming the imbalance between slow Na+ reaction kinetics of battery-type anodes and rapid ion adsorption/desorption of capacitive cathodes is a significant challenge. Here, we propose the high-rate-performance NiS2@OMGC anode material composed of monodispersed NiS2 nanocrystals (8.8 ± 1.7 nm in size) and N, S-co-doped graphenic carbon (GC). The NiS2@OMGC material has a three-dimensionally ordered macroporous (3DOM) morphology, and numerous NiS2 nanocrystals are uniformly embedded in GC, forming a core–shell structure in the local area. Ultrafine NiS2 nanocrystals and their nano–microstructure demonstrate high pseudocapacitive Na-storage capability and thus excellent rate performance (355.7 mAh/g at 20.0 A/g). A SIHC device fabricated using NiS2@OMGC and commercial activated carbon (AC) cathode exhibits ultrahigh energy densities (197.4 Wh/kg at 398.8 W/kg) and power densities (43.9 kW/kg at 41.3 Wh/kg), together with a long life span. This outcome exemplifies the rational architecture and composition design of this type of anode material. This strategy can be extended to the design and synthesis of a wide range of high-performance electrode materials for energy storage applications. [ABSTRACT FROM AUTHOR]

Developing highly active and stable oxygen evolution reaction (OER) catalysts for water electrolysis remains a great challenge. A self-supported Ir nanocatalyst was prepared via a self-assembly method. Its porous structure and residual metal incorporation contributed to its high activity and stability for the OER in acid. [ABSTRACT FROM AUTHOR]

Metal phosphides are promising noble metal‐free electrocatalysts for hydrogen evolution reaction (HER), but they usually suffer from inferior stability and thus are far from the device applications. We reported a facile and controllable synthetic method to prepare metal‐incorporated M‐FeP nanoparticles (M=Cr, Mn, Co, Fe, Ni, Cu, and Mo) with the guide of the density functional theory (DFT). The evaluated HER activity sequence was consistent with the DFT predictions, and cobalt was revealed to be the appropriate dopant. With the optimization of the Co/Fe ratio, the Fe0.67Co0.33P/C only required overpotentials of 67 mV and 129 mV to obtain the cathodic current density of 10 and 100 mA cm−2, respectively. It maintained the initial activity in the 10 h stability test, surpassing the other Co‐FeP/C catalysts. Ex situ experiments demonstrated that the decreased element leaching and the increased surface phosphide content contributed to the high stability of the Fe0.67Co0.33P/C. A proton exchange membrane water electrolyzer was assembled using the Fe0.67Co0.33P/C as the cathodic catalyst. It showed a current density of 0.8 A cm−2 at the applied voltage of 2.0 V and retained the initial activity in the 1000 cycles' stability test, suggesting the potential application of the catalysts. [ABSTRACT FROM AUTHOR]

Improving power density is considered as one of the most effective methods to decrease the cost of vanadium flow batteries (VFBs). To reduce the polarization loss of VFBs, a hollow porous carbon sphere, whose inner and outer surfaces can both provide active sites catalyzing the redox reactions of vanadium redox couples, is designed and prepared by using nickel metal–organic framework (Ni‐MOF) as a template with the assistance of polyvinylpyrrolidone (PVP). This catalyst with its high specific surface area can be simply in situ loaded on the graphite felt forming a composite electrode. The composite electrode exhibits outstanding electrocatalytic activity, as the vanadium ions can participate in the reaction on both inner and outer surfaces of the hollow spheres. As a result, a VFB single cell assembled with this electrode can achieve a high energy efficiency of 82.7% at a current density of 200 mA cm−2 and a peak power density of 958 mW cm−2, which is much higher than those of pristine graphite felts. This work provides a new idea for the development of highly active electrocatalysts for VFBs and further improves the power density of a VFB. [ABSTRACT FROM AUTHOR]

Summary: As an efficient method for the waste heat recovery of gas turbine, supercritical carbon dioxide (S‐CO2) power cycle has gained much attention, due to the high efficiency and compact structure. Thus, in this work, a novel S‐CO2 power cycle is developed for the waste heat recovery via the modification of dual heated cascade cycle with an intercooler (intercooling cycle). Compared with the dual heated cascade cycle (original cycle) and the intercooling cycle, the novel cycle has independent pressures at different heaters and turbines. To analyze the system performance, thermodynamic models are established and a genetic algorithm (GA) is applied to optimize the decision variables with the maximization of net work. These variables include two turbine inlet temperatures, a middle pressure, a low pressure, and a split ratio. Thereafter, thermodynamic parameters of the considered three cycles are obtained under different waste gas temperatures. For the recovery of 600°C waste gas, the novel cycle has the highest net work 3957.87 kW, while the lowest net work 3735.32 kW is obtained by the original cycle. For the effects of decision variables, a higher high‐temperature turbine inlet temperature means a lower net work, while the increase of low‐temperature turbine inlet temperature results in small increases of cycle performances. On the other hand, under the constraints of the pinch point, with the increase of low and middle pressures, the net work of the novel cycle increases. A higher net work is usually obtained at a lower split ratio. Furthermore, at different waste gas inlet temperatures, the highest cycle efficiency is always derived by the proposed cycle. For the net work, the proposed cycle has the highest value in the temperature range 600°C–750°C. [ABSTRACT FROM AUTHOR]

Abstract The removal characteristics of sub-25 nm ultrafine particles (UFPs) by different porous nanomaterials with different morphologies were studied based on efficiency curves obtained with specially designed filtration system. The material morphological effects on UFPs collection were investigated. The results demonstrate a complex and synergic mechanism of material structural framework, pore size distribution, and porosity order in terms of diffusion and interception dependent on flow velocity. Both porosity and fiber-like tubular structures promoted the UFPs removal. Microporosity and disordered mesoporosity could enhance the roughness of the internal surface and intensify the interaction with UFPs. Specifically, the large and ordered mesoporosity was able to render selectivity for UFPs at certain sizes and exhibited the best particle collection performance which can be largely associated with significant pore size and volume. The dependence of the ratio of diffusion to interception on flow velocity and the comparison of different pores in terms of the matching sizes with particles derived from single sphere efficiency model fitting results were also discussed. This work is significant to deeper understanding of interactions between airborne nanoparticles and porous surfaces. Graphical abstract Unlabelled Image Highlights • UFPs removal by porous materials with different morphologies was explored. • Effects of structure, pore size and order on particle collection was studied. • Relationship between diffusional collection and mesoporsity was addressed in theory. [ABSTRACT FROM AUTHOR]

To efficiently recover the waste heat of mobile engine, two advanced transcritical power cycles, namely split cycle and dual pressure cycle, are employed, based on the recuperative cycle. Performances of the two cycles are analyzed and compared through the development of thermodynamic models. Under given gas conditions, seven high-temperature working fluids, namely propane, butane, isobutane, pentane, isopentane, neopentane, and cyclopentane, are selected for the two cycles. At the design system parameters, the highest work 48.71 kW, is obtained by the split cycle with butane. For most of fluids, the split cycle has a higher work than the dual pressure cycle. Furthermore, with the increase of turbine inlet pressure, net work of the split cycle goes up firstly and then decreases, while the work of dual pressure cycle increases slowly. For the split cycle, there exists a split ratio to get the maximum network. However, for the dual pressure cycle, the larger the evaporation temperature, the higher the net work. On this basis, system parameters are optimized by genetic algorithm to maximize net work. The results indicate that the highest work 49.96 kW of split cycle is obtained by pentane. For the considered fluids, except cyclopentane, split cycle always has a higher work than dual pressure cycle. Due to the higher net work and fewer system components, split cycle is recommended for the engine waste heat recovery. [ABSTRACT FROM AUTHOR]

• A truly self-starting new representation of the ρ ∞ -Bathe method is redesigned. • A new composite time integration framework is designed for first-order systems. • A novel composite [ i -Integration] design applied to first/second-order systems. • In-depth comparisons between the composite method and the well-known GS4 framework. Due to the lack of and limited work done for first/second-order systems useful for multidisciplinary problems, this paper proposes a new and novel composite isochronous integration ([ i -Integration]) analysis framework to solve first/second-order transient systems via a single computational framework. The main contributions are summarized as follows: (1) The ρ ∞ -Bathe method is newly reformed to an identical truly self-starting representation with the absence of acceleration and is more efficient for practical applications; (2) The novel [ i -Integration] process is applied to automatically generate a family of time integration algorithms for first/second-order transient systems, whilst preserving features of second-order time accuracy, unconditional stability, controllable numerical dissipation in high-frequency, and truly self-starting; (3) The newly proposed algorithms design framework provides a unified toolkit to solve first/second-order transient systems in a single analysis and hence is more effective for coupled problems and numerical analysis of fluid/heat transfer/structure-type transient simulations. Numerical examples encompassing a manufactured example, the C-F heat conduction model, and the thermal stress wave problem are demonstrated to validate the proposed algorithms. [ABSTRACT FROM AUTHOR]

Airborne ultrafine nanoparticle (UFNP) is a key factor causing heavy haze pollution in Beijing-Tianjin-Hebei, which is very harmful to human health and the environment. Removal of environmental UFNPs by porous material is an important method of air purification treatment. However, the specific mechanism by which porous material filters UFNPs is not clear. In this study, UFNPs with 2–10 nm diameter were removed by SBA-15 mesoporous silica molecular sieves with different pore sizes, and the filtration mechanism was analyzed using transmission electron microscopy (TEM), specific surface area tests (BET), and X-ray photoelectron spectroscopy (XPS). The analyses showed a distinctive filtration of UFNPs over the interior mesopore channels. The removal efficiencies of SBA-15 with different pore sizes were also compared, demonstrating the influence of the pore size and structure on most penetrating particle size (MPPS). The UFNP filtration efficiency of SBA-15 increased with the increase of pore size. Moreover, SBA-15-14.6 could effectively purify UFNPs, and it had the highest fractional diffusive filtration efficiency of 98.79% and a total efficiency of 92.58% for UFNPs. This study provides a technical basis for the filtration of UFNPs using mesoporous materials. [ABSTRACT FROM AUTHOR]

Metal phosphides are promising noble metal-free electrocatalysts for hydrogen evolution reaction (HER), but they usually suffer from inferior stability and thus are far from the device applications. We reported a facile and controllable synthetic method to prepare metal-incorporated M-FeP nanoparticles (M=Cr, Mn, Co, Fe, Ni, Cu, and Mo) with the guide of the density functional theory (DFT). The evaluated HER activity sequence was consistent with the DFT predictions, and cobalt was revealed to be the appropriate dopant. With the optimization of the Co/Fe ratio, the Fe 0.67 Co 0.33 P/C only required overpotentials of 67 mV and 129 mV to obtain the cathodic current density of 10 and 100 mA cm -2, respectively. It maintained the initial activity in the 10 h stability test, surpassing the other Co-FeP/C catalysts. Ex situ experiments demonstrated that the decreased element leaching and the increased surface phosphide content contributed to the high stability of the Fe 0.67 Co 0.33 P/C. A proton exchange membrane water electrolyzer was assembled using the Fe 0.67 Co 0.33 P/C as the cathodic catalyst. It showed a current density of 0.8 A cm -2 at the applied voltage of 2.0 V and retained the initial activity in the 1000 cycles' stability test, suggesting the potential application of the catalysts., (© 2022 Wiley-VCH GmbH.)

Photoacoustic (PA) imaging in the second near-infrared (NIR-II) window has gained more and more attention in recent years and showed great potential in the field of bioimaging. Until now, numerous materials have been developed as contrast agents for NIR-II PA imaging. Among them, small molecule dyes hold unique advantages such as definite structures and capability of fast clearance from body. By virtue of these advantages, small molecule dyes-constructed nanoparticles have relatively small size and show promise in the clinical translation. Thus, in this minireview, we summarize recent advances in small molecule dyes-based nanotheranostics for NIR-II PA imaging and cancer therapy. Studies about NIR-II PA imaging-guided phototherapy are first introduced. Then, NIR-II PA imaging-guided phototherapy-based combination therapeutic systems are reviewed. Finally, the conclusion and perspectives of this field are summarized and discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zhou, Yin, Zhang, Liang, Guo, Liu, Xie and Fan.)

Iron phosphide nanoparticles (NPs) are promising noble metal-free electrocatalysts for the hydrogen evolution reaction (HER), but they usually show inferior activity due to the limited surface area and oxidative passivation. We reported a facile synthetic method to prepare FeP hollow NPs (HNPs) with various precursors. It was proven that the structural parameters (i.e., size, phosphating temperature, phase, and surfactant) of oxide precursors were correlated to the electrochemically active surface area (ECSA), phase purity, surface oxidation, and hollow morphology of FeP HER catalysts, thus affecting the HER activity. Among the three FeP HNPs, the 9 nm FeP HNPs prepared using the Fe 3 O 4 precursor exhibited the highest overall activity with the lowest overpotential of 76 mV to drive a cathodic current density of 10 mA·cm -2 due to the highest ECSA, while 25 nm FeP prepared using the Fe 2 O 3 precursor showed the highest turnover frequency because of the high phase purity and low surface oxidation degree.