流量阶跃变化时供暖房间内温度场的数值模拟

两位通断式调节是一种计量供热系统控制模式,与欧洲供热系统控制模式不同的是,其温控阀只有启、闭两种状态.用数值模拟方法研究了该调控模式对室内热环境的影响规律.     

Enhanced Photocatalytic Activity of Lead-Free Cs2TeBr6/g-C3N4 Heterojunction Photocatalyst and Its Mechanism

In this study, a new type of lead-free double perovskite Cs₂TeBr₆ combined with metal-free semiconductor g-C₃N₄ heterojunction is constructed and used for photocatalytic CO₂ reduction for the first time. The S-scheme charge transfer mechanism between Cs₂TeBr₆ and g-C₃N₄ is systematically verified by X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR) and in situ Fourier infrared spectroscopy(FT-IR). The formation of S-type heterojunction makes the photocatalyst have higher charge separation ability and highest redox ability. The results show that 5%-CTB/CN heterojunction material has the best photocatalytic reduction effect on CO₂ under visible light irradiation. After 3 h of illumination, the yield of CO and CH₄ are 468.9 µmol g⁻¹ and 61.31 µmol g⁻¹, respectively. The yield of CO is 1.5 times and 32 times that of pure Cs₂TeBr₆ and g-C₃N₄, and the yield of CH₄ is doubled compared with pure Cs₂TeBr₆. However, g-C₃N₄ almost does not produce CH₄, which indicates that the construction of heterojunction helps to further improve the photocatalytic performance of the material. This study provides a new idea for the preparation of Cs₂TeBr₆/g-C₃N₄ heterojunction and its effective interfacial charge separation.     

A Stress Self-Adaptive Bimetallic Stellar Nanosphere for High-Energy Sodium-Ion Batteries

Bimetallic composites exhibit great potential as anode materials in advanced energy storage systems owing to their inherent tunability, cost-effectiveness, and simultaneous achievement of high specific capacity and low reaction potential. However, simple biphase mixing often fails to achieve satisfactory performance. Herein, an innovative stress self-adaptive bimetallic stellar nanosphere (50–200 nm) wherein bismuth (Bi) is fabricated, as a core, is seamlessly encapsulated by a tin (Sn) sneath (Sn-Bi@C). This well-integrated stellar configuration with bimetallic nature embodies the synergy between Bi and Sn, offering fortified conductivity and heightened sodium ion diffusion kinetics. Moreover, through meticulous utilization of finite element analysis simulations, a homogeneous stress distribution within the Sn-enveloped Bi, efficiently mitigating the structural strain raised from the insertion of Na⁺ ions, is uncovered. The corresponding electrode demonstrates remarkable cyclic stability, as it exhibits no capacity decay after 100 cycles at 0.1 A g⁻¹. Furthermore, it achieves an impressive 86.9% capacity retention even after an extensive 2000 cycles. When employed in a Na₃V₂(PO₄)₃ ‖ Sn-Bi@C full cell configuration, it demonstrates exceptional capacity retention of 97.06% after 300 cycles at 1 A g⁻¹, along with a high energy density of 251.2 W h kg⁻¹.     

Nanoengineering Calcium Peroxide-Based Site-Specific Delivery Platform to Efficiently Activate the cGAS-STING Pathway for Cancer Immunotherapy by Amplified Endoplasmic Reticulum Stress

Currently, the understanding of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway's involvement in efficient immunotherapy mainly revolves around the role of mitochondria or nucleus modulation. Nonetheless, the role of endoplasmic reticulum (ER) stress in activating the cGAS-STING mechanism to boost immunity against tumors remains essentially unexplored. Herein, novel findings demonstrating that ER stress can be used as a strategy for stimulating the cGAS-STING pathway, thereby augmenting the immune response against cancer, are presented. To accomplish this objective, ER-targeting p-methylbenzene sulfonamide-tailored IR780 (p-780) is synthesized and it is loaded into CaO₂ nanoparticles, which are further functionalized with distearoyl phosphoethanolamine-polyethylene glycol（DSPE-PEG）-biotin to form PEG/CaO₂@p-780 NPs. The disruption of calcium homeostasis, coupled with the heightened levels of reactive oxygen species (ROS) mediated by p-780, along with hyperpyrexia, collectively contributes to the amplification of endoplasmic reticulum (ER) stress. This cascade of events effectively triggers the cGAS-STING pathway and, in parallel, facilitates the degradation of the programmed cell death 1 ligand 1 (PD-L1) protein. In addition, oxygen released through CaO₂ decomposition is expected to promote p-780–mediated phototherapy, while reversing the immunosuppressive tumor microenvironment associated with hypoxia. Furthermore, DSPE-PEG-biotin facilitates tumor site-specific drug delivery through active targeting mediated by the biotin receptor. Collectively, PEG/CaO₂@p-780 nanoparticles successfully activate systemic antitumor immunity by enhancing ER stress.     

Enhanced Air Stability and Li Metal Compatibility of Li-Argyrodite Electrolytes Triggered by In2O3 Co-Doping for All-Solid-State Li Metal Batteries

Sulfide solid electrolytes (SSEs) have become an ideal candidate material for all-solid-state Li metal batteries (ASSLMBs) because of their high ionic conductivity. However, the vile Li incompatibility and poor air stability of SSEs barriers their commercial application. Herein, novel Li_6+2xP_1−xIn_xS_5−1.5xO_1.5xCl (0 ≤ x ≤ 0.1) SSEs are synthesized via In and O co-doped Li₆PS₅Cl. By regulating the substitution concentration, the prepared Li_6.12P_0.92In_0.08S_4.88O_0.12Cl exhibits considerable ionic conductivity (2.67 × 10⁻³ S cm⁻¹) and enhanced air stability. Based on the first-principles density functional theory (DFT) calculation, it is predicted that In³⁺ replaces P⁵⁺ to form InS₄⁵⁻ tetrahedron and O²⁻ replaces S²⁻ to form PS₃O⁴⁻ group. The mechanism of enhancing air stability by In, O co-substituting Li₆PS₅Cl is clarified. More remarkably, the formation of Li-In alloys induced by Li_6.16P_0.92In_0.08S_4.88O_0.12Cl electrolyte at the anode interface is beneficial to reducing the migration barrier of Li-ions, promoting their remote migration, and enhancing the stability of the Li/SSEs interface. The optimized electrolyte shows superior critical current density (1.4 mA cm⁻²) and satisfactory Li dendrite inhibition (stable cycle at 0.1 mA cm⁻² over 3000 h). The ASSLMBs with Li_6.16P_0.92In_0.08S_4.88O_0.12Cl electrolyte reveal considerable cycle stability. This work emphasizes In, O co-doping to address redox issues of sulfide electrolytes.     

Feedforward Photoadaptive Organic Neuromorphic Transistor with Mixed-Weight Plasticity for Augmenting Perception

Organic photoelectric neuromorphic devices that mimic the brain are widely explored for advanced perceptual computing. However, current individual neuromorphic synaptic devices mainly focus on utilizing linear models to process optoelectronic signals, which means that there is a lack of effective response to nonlinear structural information from the real world, severely limiting the computational efficiency and adaptability of networks to static and dynamic information. Here, a feedforward photoadaptive organic neuromorphic transistor with mixed-weight plasticity is reported. By introducing the potential of the space charge to couple gate potential, photoexcitation, and photoinhibition occur successively in the channel under the interference of constant light intensity, which enables the device to transform from a linear model to a nonlinear model. As a result, the device exhibits a dynamic range of over 100 dB, exceeding the currently reported similar neuromorphic synaptic devices. Further, the device achieves adaptive tone mapping within 5 s for static information and achieves over 90% robustness recognition accuracy for dynamic information. Therefore, this work provides a new strategy for developing advanced neuromorphic devices and has great potential in the fields of intelligent driving and brain-like computing.     

Epitaxial Growth of 1D Te/2D MoSe2 Mixed-Dimensional Heterostructures for High-Efficient Self-Powered Photodetector

Mixed-dimensional heterostructures provide additional freedom to construct diverse functional electronic and optoelectronic devices, gaining significant interest. Herein, highly-aligned pseudo-1D tellurium is epitaxially grown on 2D monolayer transition metal dichalcogenides (TMDs), including MoSe₂, MoS₂, and WS₂. A one-pot chemical vapor deposition (CVD) technique eliminates the normally required transfer steps, thereby producing mixed-dimensional heterostructures with an ultraclean interface. The controllable epitaxial growth of Te/TMD heterostructures are verified by Raman, scanning probe microscopy (SPM), and transmission electron microscopy (TEM) observation. The photoluminescence results indicate that the emission from TMDs is quenched in the heterostructure, confirming the efficient transfer of photogenerated carriers from TMDs to Te. Additionally, the mixed-dimensional p-n Te/MoSe₂ heterojunction photodetector presents self-driven behavior with high responsivity (328 mA W⁻¹), external quantum efficiency (79%), and specific detectivity (8.2 × 10⁹ Jones). The modified facile synthesis strategy and proposed growth mechanism in this study shed light on synthesizing mixed-dimensional heterojunctions. This opens avenues for fabricating functional devices with reduced sizes and high densities, further enabling miniaturization and integration opportunities.     

Growth of GaN Thin Films Using Plasma Enhanced Atomic Layer Deposition: Effect of Ammonia-Containing Plasma Power on Residual Oxygen Capture

In recent years, the application of (In, Al, Ga)N materials in photovoltaic devices has attracted much attention. Like InGaN, it is a direct band gap material with high absorption at the band edge, suitable for high efficiency photovoltaic devices. Nonetheless, it is important to deposit high-quality GaN material as a foundation. Plasma-enhanced atomic layer deposition (PEALD) combines the advantages of the ALD process with the use of plasma and is often used to deposit thin films with different needs. However, residual oxygen during growth has always been an unavoidable issue affecting the quality of the resulting film, especially in growing gallium nitride (GaN) films. In this study, the NH₃-containing plasma was used to capture the oxygen absorbed on the growing surface to improve the quality of GaN films. By diagnosing the plasma, NH₂, NH, and H radicals controlled by the plasma power has a strong influence not only on the oxygen content in growing GaN films but also on the growth rate, crystallinity, and surface roughness. The NH and NH₂ radicals contribute to the growth of GaN films while the H radicals selectively dissociate Ga-OH bonds on the film surface and etch the grown films. At high plasma power, the GaN film with the lowest Ga-O bond ratio has a saturated growth rate, a better crystallinity, a rougher surface, and a lower bandgap. In addition, the deposition mechanism of GaN thin films prepared with a trimethylgallium metal source and NH₃/Ar plasma PEALD involving oxygen participation or not is also discussed in the study.     

天然气制合成油的发展前景

天然气制合成油(Gas to Liquid)是最近几年广泛关注的热点,主要介绍了GTL生产工艺及其发展促进因素,并预测了其在中国的发展前景.     

高应力区大体积混凝土基础破坏机理分析与治理技术研究

分析了高应力区大体积混凝土破坏的原因和机理,提出了综合采用卸压沟、基础底部锚网梁等防治高应力区大体积混凝土基础破坏的方法,有效的解决了高应力区内大体积设备基础易破坏的难题。