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This work investigates the effect of cyclic creep on the long-term oxidation of a directionally-solidified nickel-based superalloy DZ445 up to 1800 h. The stress application of cyclic creep refines the oxides, increases the oxidation weight gain, reduces the oxidation rate exponent, and decreases the activation energy. It enhances the content of Al2O3and TiO2in the outermost layer and in the sub-outer layer of CrTaO4in the film. It delays the formation of the continuous innermost layer of Al2O3and the sub-inner layer that is rich in Al2O3. The change of phase content and type in the oxidation layers could be ascribed to the diffusion kinetic effect of cyclic creep stress in the superalloy.

In order to address the issues of low efficiency, large size, and low output power quality in the two-stage inverter power supply, this paper focuses on the series-resonant push–pull converter and conducts an in-depth analysis of its different operating modes. Two critical operating modes of the converter are identified, and optimal parameter designs for the resonant components under different critical operating modes are derived through time-domain analysis. The reasons and consequences of the double-frequency ripple voltage on the two-stage circuit bus are analyzed, and a modulation wave reconstruction nonlinear feedforward control strategy is proposed to real-time correct the modulation signal and reduce the impact of bus ripple voltage on the output power quality. Finally, simulation models and experimental platforms are built to validate the correctness of the theory. The experimental prototype is designed to operate in the second critical mode, and the results show that the proposed scheme can enhance the peak efficiency of the power supply by 5%, reduce the volume by 40%, and decrease the output voltage total harmonic distortion (THD) by 0.56%, effectively improving the efficiency and output power quality of the inverter power supply.

Morphotropic phase boundary (MPB) plays a key role in tuning piezoelectric responses of ferroelectric ceramics. Here, Bi0·5Na0·5TiO3modified BiFeO3BaTiO3ternary solid solutions of 0.7BiFeO3-(0.3-x)BaTiO3-xBi0.5Na0·5TiO3(referred to as BF-BT-xBNT, 0.00 ≤ x ≤ 0.04) were prepared for lead-free piezoelectrics. All the ceramics exhibit an MPB with coexisting rhombohedral (R) and tetragonal (T) phases, and the R/T phase ratio decreases upon increasing x. The increment of BNT promotes the grain growth, lowers the leakage current and Curie temperature (TC), and gradually drives the ferroelectric to relaxor transition. Because of the MPB with appropriate R/T phase ratio, increased grain size and density, and decreased leakage current, the well-balanced performance between d33 = 206 pC/N and TC = 488 °C is obtained in x = 0.01 case. In addition, the further enhanced in-situ d33 = 286–347 pC/N is obtained in BF-BT-xBNT ceramics along with the improved depolarization temperature Tdfrom 280 to 312 °C, showing a potential application for lead-free piezoceramics at high temperature.

ABSTRACTDespite the continuous acceleration of global industrial informatization process, the manufacturing industry is still facing many problems, such as the lack of data in the machining process, the low utilization rate of energy and so on. This paper proposes an integrated framework based on Internet of things (IoT) and machine learning to realize the monitoring and collection of original real-time data, data association and achieve the trade-off optimization among energy consumption, processing time and surface roughness for the milling process in manufacturing system. This framework is composed of four functional modules, i.e. IoT-based processing data acquisition, milling experiment design, performance index prediction based on machine learning and performance index multi-objective optimization. The optimization results exhibit obvious advantages in energy consumption saving, processing time reduction and surface roughness improvement for the milling process.

An appropriate infusible method plays a vital role as one of the key processes of the fabrication of polymer-derived ceramic fibers. In this work, ozone curing, a novel room temperature controllable curing strategy was used to prepare SiCN ceramic fibers. Some circular pores were observed on the surface of the obtained SiCN ceramic fibers. The tensile strength of the fibers was also investigated. To reveal the ozone-curing mechanisms of the PSZ fibers and the formation process of the circular pores, the FT-IR, SEM, OM, XRD and TG were characterized. The results showed that the Si–H bonds and Si-CH3groups in the PSZ molecule were oxidized gradually to form oxygen-containing groups such as Si–OH, Si–O-Si and C = O in the ozone curing process, which contributed to the curing and weight gain of the PSZ fibers. Moreover, a hydrolysis reaction between Si-NH-Si and H2O might further accelerate the curing of the PSZ fibers. An unexpected result of the hydrolysis reaction is the formation of some circular pores on the surface layer of the PSZ fibers. This strategy provides a method to design, adjust and control the microstructure and composition of silicon-based ceramic fibers, and the obtained SiCN fibers may be used as catalyst support, bacterial culture and other fields.

The effect of MOFs-derived Ce0.3Ni0.7Oxcarrier (CN-M) on Pd dispersion states for three-way catalytic (TWC) performance of natural gas vehicles (NGVs) comparing with Ce0.3Ni0.7Oxcarrier (CN-C) prepared by citric acid complexation method has been studied. The results showed that the Pd/CN-M catalyst displayed better Pd dispersion (46.3%) and much higher activity for the conversions of CO, NO and CH4. Both T50and T90of CO conversion over Pd/CN-M were lower ca. 100 °C than that over Pd/CN-C catalyst, T50and T90of NO conversion were same trend with lower degree ca. 150 °C, the CH4conversion of Pd/CN-M was also much better than that of Pd/CN-C. After thermal aging, the conversions of CO, NO and CH4of Pd/CN-M had a finite shift with 20–50 °C to high temperature. It showed unique structure, smaller crystal particles, higher metal dispersion, stronger reducibility, and higher adsorbed oxygen (Oα) on Pd/CN-M catalyst in comparison to Pd/CN-C, and dispersion thermal stabilization of Pd particles on Pd/CN-M catalyst was better than that on Pd/CN-C. This work maybe provides a new method for preparing TWCs with high active for NGVs.

Ryegrass green manure (RG) and biochar (BC) induced the simplification of microbial networks and an increase in fungi’s random assembly processes.RG promoted denitrification and carbon degradation functional genes, while BC enhanced nitrogen fixation genes.RG accelerated soil energy flow by promoting M00307 and M00061.In RG-treated soil, the main metabolites were Carbohydrates, while in BC-treated soil, the main metabolites were Acids and Amines. Both treatments reduced soil pollutant bisphenol A.

Cu-based catalysts are optimal for the electroreduction of CO2to generate hydrocarbon products. However, controlling product distribution remains a challenging topic. The theoretical investigations have revealed that the coordination number (CN) of Cu considerably influences the adsorption energy of *CO intermediates, thereby affecting the reaction pathway. Cu catalysts with different CNs were fabricated by reducing CuO precursors via cyclic voltammetry (Cyc-Cu), potentiostatic electrolysis (Pot-Cu), and pulsed electrolysis (Pul-Cu), respectively. High-CN Cu catalysts predominantly generate C2+products, while low-CN Cu favors CH4production. For instance, over the high-CN Pot-Cu, C2+is the main product, with the Faradaic efficiency (FE) reaching 82.5% and a partial current density (j) of 514.3 mA cm–2. Conversely, the low-CN Pul(3)-Cu favors the production of CH4, achieving the highest FECH4value of 56.7% with a jCH4value of 234.4 mA cm–2. In situ X-ray absorption spectroscopy and Raman spectroscopy studies further confirm the different *CO adsorptions over Cu catalysts with different CN, thereby directing the reaction pathway of the CO2RR.

Over the last few decades, the construction industry has witnessed a growing utilization of aluminum alloys, primarily due to their beneficial characteristics. This trend has sparked numerous research endeavors seeking a more comprehensive understanding of the structural behavior of these alloys, as well as the development of accurate and dependable design principles. This paper aims to provide an all-encompassing review of the existing body of research in this field, delving into the experimental, numerical, and analytical investigations conducted on structural aluminum alloys. The scope of this review encompasses studies that focus on the mechanical properties of aluminum alloys when subjected to monotonic, cyclic, and thermal loading conditions. Additionally, a significant amount of attention is dedicated to examining the structural performance and design considerations pertaining to aluminum columns, beams, and plates, incorporating both experimental and numerical approaches. Furthermore, the performance of connections and composite aluminum-concrete members is thoroughly discussed. The assessment of the applicability of international design specifications to structural aluminum alloys is also addressed in this paper. Throughout the review process, various gaps in our current knowledge are identified, and recommendations for future research endeavors aimed at bridging these gaps are proposed.

The most broadly used powder bed fusion (PBF) technique is Selective laser melting (SLM), which is mainly employed for the fabrication of thin-walled, lightweight structures of aluminum alloys, titanium alloys, steel alloys, etc. Currently, fully dense manufacturing of thin-walled structures with good strength is significant. In this paper, thin-walled test specimens were fabricated by using the optimal processing parameters with varying wall thickness. The goal of the paper is to study the effect of wall thickness on the hardness of the thin-walled specimens. It is concluded that wall thickness has a significant effect on the hardness of the product. The maximum hardness of 137.3 HV is obtained for a wall thickness of 5.0 mm and the minimum hardness of 102.4 HV for 1.0 mm wall thickness specimen.

Sn-based materials are considered as a kind of potential anode materials for lithium-ion batteries (LIBs) owing to their high theoretical capacity. However, their use is limited by large volume expansion deriving from the lithiation/delithiation process. In this work, amorphous Sn modified nitrogen-doped porous carbon nanosheets (ASn-NPCNs) are obtained. The synergistic effect of amorphous Sn and high edge-nitrogen-doped level porous carbon nanosheets provides ASn-NPCNs with multiple advantages containing abundant defect sites, high specific surface area (214.9 m2·g−1), and rich hierarchical pores, which can promote the lithium-ion storage. Serving as the LIB anode, the as-prepared ASn-NPCNs-750 electrode exhibits an ultrahigh capacity of 1643 mAh·g−1at 0.1 A·g−1, ultrafast rate performance of 490 mAh·g−1at 10 A·g−1, and superior long-term cycling performance of 988 mAh·g−1at 1 A·g−1after 2000 cycles with a capacity retention of 98.9%. Furthermore, the in-depth electrochemical kinetic test confirms that the ultrahigh-capacity and fast-charging performance of the ASn-NPCNs-750 electrode is ascribed to the rapid capacitive mechanism. These impressive results indicate that ASn-NPCNs-750 can be a potential anode material for high-capacity and fast-charging LIBs.

Most reported nitrogen-doped carbon anode materials of lithium-ion batteries (LIBs) own finite capacities and inferior initial coulombic efficiency (ICE). One effective method to enhance capacities and capacities of the nitrogen-doped carbon anode materials is edge‑nitrogen doping. It still endures obstacles to realize a high edge‑nitrogen doping level owing to the difficulty to control of the nitrogen doping types. In this work, a series of edge‑nitrogen-doped porous carbon (ENPC) with different edge‑nitrogen doping levels are synthesized by annealing sucrose and g-C3N4in a sealed graphite crucible. The edge‑nitrogen doping level from 8.88 at.% to 12.93 at.% for the ENPC-T can be regulated by changing the annealing temperature. Serving as LIBs anodes, the ENPC-800 exhibits an excellent capacity (1251.1 mAh g−1at 0.1 A g−1), high ICE (82.9 %) and remarkable cycle life (650.5 mAh g−1at 1 A g−1after 1000 cycles with an exceptional capacity retention of 99.3 %). More significantly, by correlating the capacity and conductivity with the nitrogen doping configuration of the ENPC-T materials, the results highlight the effect of edge‑nitrogen on the capacity and conductivity. Meanwhile, the electrochemical characterizations of CV, GITT and EIS illustrate that a higher edge‑nitrogen doping level improves the capacity, electronic conductivity and fast-charging performance of ENPC-T. This new strategy can pave a new approach for the investigation and application of nitrogen-doped carbon anodes.

The successful deployment of proton-exchange membrane water electrolyzers (PEMWEs) relies on the development of an active and durable electrocatalyst for the anodic oxygen evolution reaction (OER). Although rutile IrO2shows excellent durability due to its stable crystal structure, it suffers from unsatisfactory activity. Here, we report a partial Sn substitution strategy to trigger lattice oxygen reactivity toward boosted OER. The similar crystal structures of IrO2and SnO2promote uniform incorporation of Sn into the lattice of IrO2, thus retaining the durability of the pristine rutile phase. More importantly, the electron transfer from Ir to Sn through the local structure of Ir–O–Sn was found to enhance the Ir–O bond covalency, which in turn activated the lattice oxygen to participate in OER. The enhanced lattice oxygen mechanism (LOM) was further verified by in situ 18O isotope labeling in situ differential electrochemical mass spectroscopy (DEMS). Due to these attributes, the as-designed Ir0.83Sn0.17O2catalyst showed significantly improved performance, with an overpotential of only 284 mV at a current density of 10 mA cm–2, 38 mV lower than that of the commercial IrO2. In addition, the mass activity of the Ir0.83Sn0.17O2catalyst reaches as high as 130 A gIr–1at 1.55 V, which is 2.58 times higher than that of commercial IrO2. Beyond that, the intrinsic stability of the rutile phase endows the Ir0.83Sn0.17O2catalyst with excellent operational durability. This work provides a novel insight into the improvement of catalyst activity and inspires the design of highly active and stable OER catalysts.

Using bulk metals as catalysts to get high efficiency in electro-reduction of CO2is ideal but challenging. Here, we report the coupling of bulk metal electrodes and a ternary ionic-liquid-based electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate/1-dodecyl-3-methylimidazolium tetrafluoroborate/MeCN to realize highly efficient electro-reduction of CO2to CO. Over various bulk metal electrodes, the ternary electrolyte not only increases the current density but also suppresses the hydrogen evolution reaction to obtain a high Faradaic efficiency (FE) toward CO. FECOcould maintain ∼100% over a wide potential range, and metal electrodes showed very high stability in the ternary electrolyte. It is demonstrated that the aggregation behavior of the ternary electrolyte and the arrangement of two kinds of IL cations with different chain lengths in the electrochemical double layer not only increase the wettability to electrode and CO2adsorption but also extend the diffusion channel of H+, rendering the high current density and FECO.

The spatial organization of chromatin in the nucleus has been implicated in regulating gene expression. Maps of high-frequency interactions between different segments of chromatin have revealed topologically associating domains (TADs), within which most of the regulatory interactions are thought to occur. TADs are not homogeneous structural units but appear to be organized into a hierarchy. We present OnTAD, an optimized nested TAD caller from Hi-C data, to identify hierarchical TADs. OnTAD reveals new biological insights into the role of different TAD levels, boundary usage in gene regulation, the loop extrusion model, and compartmental domains. OnTAD is available at https://github.com/anlin00007/OnTAD.