The homojunction of oxygen/metal vacancies and its interfacial n–p effect on the physiochemical properties are rarely reported. Interfacial n–p homojunctions of TiO2 are fabricated by directly ...decorating interfacial p‐type titanium‐defected TiO2 around n‐type oxygen‐defected TiO2 nanocrystals in amorphous–anatase homogeneous nanostructures. Experimental measurements and theoretical calculations on the cell lattice parameters show that the homojunction of oxygen and titanium vacancies changes the charge density of TiO2; a strong EPR signal caused by oxygen vacancies and an unreported strong titanium vacancies signal of 2D 1H TQ‐SQ MAS NMR are present. Amorphous–anatase TiO2 shows significant performance regarding the photogeneration current, photocatalysis, and energy storage, owing to interfacial n‐type to p‐type conductivity with high charge mobility and less structural confinement of amorphous clusters. A new “homojunction of oxygen and titanium vacancies” concept, characteristics, and mechanism are proposed at an atomic‐/nanoscale to clarify the generation of oxygen vacancies and titanium vacancies as well as the interface electron transfer.
The homojunction of oxygen and titanium vacancies developed in the amorphous–anatase interface of nanostructured TiO2 results in a unique n–p electronic transmission, which is mostly preferred to the mobility of electronic charge carriers. It also contributes to significant performance regarding photogeneration current, photocatalysis, and energy storage.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Indole diketopiperazine alkaloids are secondary metabolites of microorganisms that are widely distributed in filamentous fungi, especially in the genera Aspergillus and Penicillium of the phylum ...Ascomycota or sac fungi. These alkaloids represent a group of natural products characterized by diversity in both chemical structures and biological activities. This review aims to summarize 166 indole diketopiperazine alkaloids from fungi published from 1944 to mid-2015. The emphasis is on diverse chemical structures within these alkaloids and their relevant biological activities. The aim is to assess which of these compounds merit further study for purposes of drug development.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
The heterogeneous nature of tumour microenvironment (TME) underlying diverse treatment responses remains unclear in nasopharyngeal carcinoma (NPC). Here, we profile 176,447 cells from 10 NPC ...tumour-blood pairs, using single-cell transcriptome coupled with T cell receptor sequencing. Our analyses reveal 53 cell subtypes, including tumour-infiltrating CD8
T, regulatory T (Treg), and dendritic cells (DCs), as well as malignant cells with different Epstein-Barr virus infection status. Trajectory analyses reveal exhausted CD8
T and immune-suppressive TNFRSF4
Treg cells in tumours might derive from peripheral CX3CR1
CD8
T and naïve Treg cells, respectively. Moreover, we identify immune-regulatory and tolerogenic LAMP3
DCs. Noteworthily, we observe intensive inter-cell interactions among LAMP3
DCs, Treg, exhausted CD8
T, and malignant cells, suggesting potential cross-talks to foster an immune-suppressive niche for the TME. Collectively, our study uncovers the heterogeneity and interacting molecules of the TME in NPC at single-cell resolution, which provide insights into the mechanisms underlying NPC progression and the development of precise therapies for NPC.
The equipment cabins of high‐speed trains encountered alternating pressure loads during operation. A fatigue evaluation methodology based on sub‐zone aerodynamic loading was proposed. Theoretical ...model was given between pressure load at each zone and the accompanying six structural stress components. Stress recovery matrix was formulated by finite element analysis (FEA) in sub‐zone loading cases to relate the stress to the measured pressure loads. Vehicle test gathered the pressure time‐history data of cabin sub‐zones at the head car in different ambient conditions, from which the two‐dimensional stress spectrum was derived by rain‐flow counting. The fatigue damage of welds was then assessed utilizing the Miner's and Corten Dolan's rules, yielding maximum equivalent damages of 0.72 and 0.23, respectively. The structural fatigue damage under high environmental wind conditions was 1–3 times greater than in calm weather. Nonetheless, the fatigue damage incurred by the metal matrix was significantly lower, demonstrating a substantial safety margin.
Highlights
Proposed a sub‐zone aerodynamic load‐stress conversion model.
Welds exhibit higher aerodynamic fatigue damage than metal matrix.
Strong winds heighten fatigue damage in the equipment cabin of high‐speed trains.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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•A new WPD-FEEMD-Elman method is proposed for the wind speed predictions.•A new secondary algorithm is presented for the wind speed decomposition.•The FEEMD algorithm is adopted in ...the hybrid decomposition.•The Elman neural network is employed in the hybrid forecasting.
Wind speed forecasting technology is important in the field of wind power. However, the wind speed signals are always nonlinear and non-stationary so that it is difficult to predict them accurately. Aims at this challenge, a new hybrid approach has been proposed for the wind speed high-accuracy predictions based on the Secondary Decomposition Algorithm (SDA) and the Elman neural networks. The proposed SDA combines the Wavelet Packet Decomposition (WPD) and the Fast Ensemble Empirical Mode Decomposition (FEEMD), which includes twice decomposing processes as: (a) the WPD decomposes the original wind speed into the appropriate components and the detailed components; and (b) the FEEMD further decomposes the WPD generating detailed components into a number of wind speed Intrinsic Mode Functions (IMFs). The experimental results in five real forecasting cases show that: (a) the proposed hybrid WPD-FEEMD-Elman model has satisfactory performance in the multi-step wind speed predictions; and (b) the hybrid WPD-FEEMD-Elman model has improved the forecasting performance of the hybrid WPD-Elman model and the standard Elman neural networks considerably.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Optimizing the allocation of emissions permit can yield economic welfare gains for permits importing countries.•The integration of emissions trading scheme also results in the redistribution of ...clean energy in participating countries.•The multi-region integrated ETS has significant impacts on international competiveness of each country.
Globally, emissions trading scheme (ETS) as a cost-effective method to facilitate emissions abatement is raising more and more concerns. Moreover, according to the prevailing goal to reach a global agreement for climate mitigation, integrating emissions trading schemes has emerged as a prominent international cooperation option. This paper implements different scenario analysis and simulates the establishing of a conceivable multi-region integrated emissions trading scheme with China, U.S., Europe, Australia, Japan and South Korea included by utilizing a computable general equilibrium model; specifically, the economic and energy impacts on China in context of multi-region integrated ETS are explicitly investigated. Results indicate that the integration of emissions trading schemes would optimize the allocation of emissions permit and yield economic welfare gains for permits importing countries. Countries with higher abatement cost like U.S., Japan and South Korea would reduce the national GDP loss by 0.16%, 1.33% and 1.42%, respectively. Furthermore, the integration of emissions trading scheme also results in the redistribution of clean energy in participating countries. For China, joining the multi-region integrated ETS would facilitate the development of clean energy, the proportion of which climbs up by 33.7% in MR scenario compared with BAU scenario. In addition, it is worth noting that the multi-region integrated ETS would have significant impacts on the role each region plays in international trade, leading to 11% decline of net export for China in MR scenario compared with SR scenario.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper aims at investigating the effect of the inflow turbulence on the aerodynamics and the wake instabilities of the wind turbine. The improved delayed detached eddy simulation (IDDES) combined ...with the overset grid method is performed to model the NREL S826 airfoil wind turbine at design operating condition (λ=6.0). The mean loads of power coefficient (CP) and thrust coefficient (CT) show good agreement with existing experiments data. The normalized mean velocity U/Uref profile and normalized turbulent kinetic energy k/U2ref profile within the wake is also consistent with the experiments data, indicating a fairly accurate predictions of the wake turbulence. The detailed analysis of wake vortex structure, mean Reynold's stress distribution and PSD spectrum of turbulent kinetic energy are utilized to explore the effect of incoming turbulence on the wind turbine performance and the mechanism of the wake instability. The incoming turbulence and wind shear may promote the tip vortex instability and accelerate wake recovery, thus more attention should be paid to the design procedure and layout of wind farms.
•Effect of inflow turbulence on the aerodynamics performance was studied.•Changes in the wake vortices instability due to inflow turbulence were assessed.•Results showed that incoming turbulence can accelerate wake recovery.•Power spectral density curve shifted, implying a complete turbulence wake state.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Analysis of the slipstream development around the high-speed trains in tunnels would provide references for assessing the transient gust loads on trackside workers and trackside furniture in tunnels. ...This paper focuses on the computational analysis of the slipstream caused by high-speed trains passing through double-track tunnels with a cross-sectional area of 100 m2. Three-dimensional unsteady compressible Reynolds-averaged Navier-Stokes equations and a realizable k-ε turbulence model were used to describe the airflow characteristics around a high-speed train in the tunnel. The moving boundary problem was treated using the sliding mesh technology. Three cases were simulated in this paper, including two tunnel lengths and two different configurations of the train. The train speed in these three cases was 250 km/h. The accuracy of the numerical method was validated by the experimental data from full-scale tests, and reasonable consistency was obtained. The results show that the flow field around the high-speed trains can be divided into three distinct regions: the region in front of the train nose, the annular region and the wake region. The slipstream development along the two sides of train is not in balance and offsets to the narrow side in the double-track tunnels. Due to the piston effect, the slipstream has a larger peak value in the tunnel than in open air. The tunnel length, train length and length ratio affect the slipstream velocities; in particular, the velocities increase with longer trains. Moreover, the propagation of pressure waves also induces the slipstream fluctuations: substantial velocity fluctuations mainly occur in front of the train, and weaken with the decrease in amplitude of the pressure wave.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The EU Emission Trading System (ETS) is the oldest and currently the largest carbon market in the world, but its purpose of stimulating carbon emissions via trading profits remains unexamined. Based ...on the complete firm-level transaction records of the EU ETS Phases I and II, here we show that the participating firms' trading profits and their emission abatements are positively correlated, and the correlation becomes stronger in Phase II than Phase I. Specifically, we observe that non-linearity exists in the correlation; higher firm-level emission abatements can realize larger trading profits. This pattern affects the market fairness, though it may be helpful to incentivise emission abatements. The correlation is more regulated in Phase II than it is in Phase I, thereby indicating that the Phase II is more mature. We also observe that the state-level abatements are largely driven by industrial giants.
The influences of wind angles on the behavior of a high-speed train were investigated using a scaled-down wind tunnel model (1:8 scale) at the wind angles of 0°, 5.14°, 10.2°, 15.11°, and 19.8°. ...Based on the experimental results elicited at different Reynolds numbers (9.44 × 105, 1.26 × 106, 1.57 × 106, and 1.89 × 106, corresponding to the wind speeds of 30 m/s, 40 m/s, 50 m/s, and 60 m/s, respectively), the speed of 60 m/s was determined as optimal for wind tunnel tests. The effects of the incoming flow angles on the pressure distribution of the train's streamlined zone and the aerodynamic forces of the train were analyzed. Results show that the pressure coefficients on the leeward side and the symmetrical plane profile curve of the streamlined zone decreased as the wind angle increased. However, the change in the windward side was opposite to that of the leeward side. The lateral and the absolute value of the lift forces increased rapidly as a function of the wind angle, while the drag force was maximized when the wind angle was 15.11°, followed by subsequent decreases at increasing wind angles.
•Influence of the wind angle on the aerodynamic performance of a high-speed train was investigated.•Influence of Reynolds number on the aerodynamic performance of high-speed train was investigated.•The boundary layer thickness along the train and ballast was measured and presented.•Pressure distributions along longitude direction and different cross-sections on train's streamlined zone were analyzed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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