Infilling strategies play an important role in kriging based optimization, especially when computationally expensive simulations are involved. In order to improve the efficiency of constructing a ...high-precision kriging model, an improved expected improvement criterion (IEI) and a parallel infilling strategy are proposed based on the maximum expected improvement (EI) criterion. In the proposed parallel infilling strategy, new sample points are generated by employing IEI criterion coupled with EI criterion. During the improved sampling process, redundant and pseudo sample are deleted in order to avoid failure of constructing a kriging model. An improved weighted particle swarm optimization (WPSO) algorithm is proposed to improve optimization efficiency. The proposed parallel infilling strategy is applied to nonlinear function optimization and variable blank holder force (VBHF) optimization in a double-c stamped part. Based on the LHD and software DYNAFORM, kriging models between the VBHF and forming quality are constructed. Compared with the initial kriging models, the meat relative error of kriging models with the proposed parallel infilling strategy for the wrinkling and average thinning rate are reduced by 95% and 55%, respectively. The optimal VBHF is obtained by the WPSO. The results show that, cracking has been completely eliminated and wrinkling has been decreased, greatly improving the forming quality of the double-c stamped part.
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•Cu modified Mn3O4 spinel showed excellent SCR performance and SO2 resistance.•The Eley-Rideal mechanism predominated in the low temperature SCR reaction.•The formation of MnSO4 was ...mainly responsible for the deactivation of Mn3O4.•Cu doping restrained MnSO4 generation by reducing the amounts of adjacent Mn.
Mn-based oxides are regarded as one of the most promising catalysts for selective catalytic reduction (SCR) of NOx by NH3 at low temperatures, but their applications are extremely restricted by the irreversible poisoning of SO2. Improving the SO2 tolerance of Mn-based catalyst has longtime received the most attentions from both academia and industry. In this work, a series of Cu-modified Mn3O4 spinels were synthesized, and the roles of the Cu dopant were investigated. The (Cu1.0Mn2.0)1–δO4 spinel showed both excellent SCR performance and SO2 resistance at low temperature. Cu doping improved the BET surface area, the quantities of active Mn4+ and the acid sites of Mn3O4 spinels, all of which contributed to the increase in low-temperature SCR activity. The formation of MnSO4 was mainly responsible for the irreversible deactivation of the Mn3O4 spinel upon exposure to SO2. DFT calculations suggested that SO2 was more likely to be adsorbed as “–Mn–O–S–O–Mn–” on Mn3O4 and (Cu1.0Mn2.0)1–δO4 spinels. Therefore, the formation of MnSO4 on the (Cu1.0Mn2.0)1–δO4 spinel was significantly mitigated by Cu doping, mainly due to reduced amounts of adjacent Mn. Moreover, resulting from the electronic transfer between copper and manganese cations within the spinel lattice (Cu2+ + Mn3+ ⇄ Mn4++ Cu+), the (Cu1.0Mn2.0)1–δO4 spinel retained a high surface ratio of Mn4+/Mntotal, which maintained an excellent low-temperature SCR activity under the SO2-containing condition. This work shows that doping with the low–valence dopant of Cu can significantly improve the low-temperature SCR activity and SO2 tolerance of the Mn3O4 spinel, which could be a strategy for the further design of Mn-based SCR catalysts.
The effect of water washing on LiNi0.8Co0.1Mn0.1O2 cathode is extensively studied with respect to the electrochemical properties, structural stabilities, and storage characteristics. Water washing ...can improve the cycling performance and structural stability of LiNi0.8Co0.1Mn0.1O2 material in electrolyte, although with a slight deleterious effect on the capacity. Storage tests of the 4.3 V charged electrodes at 90 °C after 30 days show that Ni, Co, Mn in fresh and washed samples are dissolved in electrolyte, but the amount of dissolved Ni4+ ions after washing decreases by 31.5% compared with the fresh cathode. Moreover, the fresh sample transforms into the spinel phase with a Fd3m space group, whereas the washed sample remains as a layered hexagonal phase with an Rm3¯ space group. FTIR spectroscopy, transmission electron microscope (TEM), X-ray diffraction (XRD) and electrochemical studies indicate that the washed materials become more easily attached upon exposure to air, accompanied by significant increase in cationic disorder and NiO-like cubic phase near surface.
Water washing can improve the cycling performance and structural stability of LiNi0.8Co0.1Mn0.1O2 material in electrolyte, although with a slight deleterious effect on the capacity. Moreover, the fresh sample transformed into the spinel phase with a Fd3m space group, whereas the washed sample remained as a layered hexagonal phase with an R3¯m space group when storing in electrolyte at 90 °C for 7 days at charged state. However, the washed materials became more easily attached upon exposure to air, accompanied by significantly increased cationic disorder and NiO-like cubic phase near surface. Display omitted
► The effect of water washing on fresh LiNi0.8Co0.1Mn0.1O2 cathode was firstly studied. ► Water washing improved the cycling performance and structural stability of material. ► Water washing resulted in a slight deleterious effect on the capacity. ► Water washing made material much less resistant to H2O and CO2 when storing in air.
Abstract This paper examines the architecture and component characteristics of the fuel tank inerting system in civil aircraft, as well as the loads it experiences. The study further investigates the ...strength of the system through a finite element model analysis by using CAEPIPE and explores the design of the bracket supporting the inerting system. The paper aims to contribute to the field by providing a detailed analysis of the fuel tank inerting system and its components, as well as offering insights into the system’s strength and design considerations.
Metal–organic frameworks (MOFs) are very promising self‐sacrificing templates for the large‐scale fabrication of new functional materials owing to their versatile functionalities and tunable ...porosities. Most conventional metal oxide electrodes derived from MOFs are limited by the low abundance of incorporated metal elements. This study reports a new strategy for the synthesis of multicomponent active metal oxides by the pyrolysis of polymetallic MOF precursors. A hollow N‐doped carbon‐coated ZnO/ZnCo2O4/CuCo2O4 nanohybrid is prepared by the thermal annealing of a polymetallic MOF with ammonium bicarbonate as a pore‐forming agent. This is the first report on the rational design and preparation of a hybrid composed of three active metal oxide components originating from MOF precursors. Interestingly, as a lithium‐ion battery anode, the developed electrode delivers a reversible capacity of 1742 mAh g−1 after 500 cycles at a current density of 0.3 mA g−1. Furthermore, the material shows large storage capacities (1009 and 667 mAh g−1), even at high current flow (3 and 10 A g−1). The remarkable high‐rate capability and outstanding long‐life cycling stability of the multidoped metal oxide benefits from the carbon‐coated integrated nanostructure with a hollow interior and the three active metal oxide components.
Hollow N‐doped carbon‐coated ZnO/ZnCo2O4/CuCo2O4 nanohybrids are prepared via thermal annealing of a polymetallic metal–organic framework in the presence of ammonium bicarbonate as a pore‐forming agent. The multidoped metal oxide components feature hollow nanostructures composed of an N‐dopant and a carbon‐coated layer. As an anode material for lithium–ion batteries, the multidoped three active metal oxide components deliver remarkable high‐rate and long‐life cycling stability.
Selective kinase inhibitors have emerged as an important class of cancer therapeutics, and several such drugs are now routinely used to treat advanced-stage disease. However, their clinical benefit ...is typically short-lived because of the relatively rapid acquisition of drug resistance following treatment response. Accumulating preclinical and clinical data point to a role for a heterogeneous response to treatment within a subpopulation of tumor cells that are intrinsically drug-resistant, such as cancer stem cells. We have previously described an epigenetically determined reversibly drug-tolerant subpopulation of cancer cells that share some properties with cancer stem cells. Here, we define a requirement for the previously established cancer stem cell marker ALDH (aldehyde dehydrogenase) in the maintenance of this drug-tolerant subpopulation. We find that ALDH protects the drug-tolerant subpopulation from the potentially toxic effects of elevated levels of reactive oxygen species (ROS) in these cells, and pharmacologic disruption of ALDH activity leads to accumulation of ROS to toxic levels, consequent DNA damage, and apoptosis specifically within the drug-tolerant subpopulation. Combining ALDH inhibition with other kinase-directed treatments delayed treatment relapse in vitro and in vivo, revealing a novel combination treatment strategy for cancers that might otherwise rapidly relapse following single-agent therapy.
The electron‐deficient ester group substitution in the sidechain of the commonly used electron‐withdrawing quinoxaline (Qx) unit is seldom studied, while ester‐substituted Qx units possess easy ...syntheses and facile modulation of the polymer solubility, and the enhanced electron‐withdrawing property of ester substituted Qx unit can theoretically broaden the optical absorption of the resulting polymers and improve the open circuit voltage in the corresponding organic solar cells (OSCs). In this work, a novel ester‐substituted Qx‐based narrow bandgap polymer (NBG) donor material PBDTT‐EFQx, which exhibits an absorption edge of 790 nm (bandgap < 1.6 eV), is designed and synthesized. Results show that the OSCs composed of PBDTT‐EFQx and PC71BM present the highest power conversion efficiency (PCE) of 6.8%, compared to PCEs of 5.0% for PBDTT‐EFQx:ITIC based devices and 4.1% for PBDTT‐EFQx:N2200 based devices, respectively. Characterizations and analyses indicate that the PC71BM‐based OSCs have well‐matched energy levels, better complementary light absorption, the highest and most balanced carrier mobilities, as well as the lowest degree of recombination losses, and therefore, leading to the highest PCE among the three types of OSCs. This work reveals that the ester‐substituted quinoxaline unit is one of the potential building blocks for NBG polymer donors.
Ester‐substituted quinoxaline (Qx) unit affords a novel narrow bandgap polymer donor material PBDTT‐EFQx, which shows broad light absorption to 790 nm. PBDTT‐EFQx gives complementary optical absorption, well‐matched energy levels, high and balanced carrier mobilities, as well as low degree of recombination losses, leading to a high power conversion efficiency of 6.8% in the PC71BM‐based devices.
Parkinson's disease (PD) is the second most prevalent dementia in the world. Wearable technology has been useful in the computer-aided diagnosis and long-term monitoring of PD in recent years. The ...fundamental issue remains how to assess the severity of PD using wearable devices in an efficient and accurate manner. However, in the real-world free-living environment, there are two difficult issues, poor annotation and class imbalance, both of which could potentially impede the automatic assessment of PD. To address these challenges, we propose a novel framework for assessing the severity of PD patient's in a free-living environment. Specifically, we use clustering methods to learn latent categories from the same activities, while latent Dirichlet allocation (LDA) topic models are utilized to capture latent features from multiple activities. Then, to mitigate the impact of data imbalance, we augment bag-level data while retaining key instance prototypes. To comprehensively demonstrate the efficacy of our proposed framework, we collected a dataset containing wearable-sensor signals from 83 individuals in real-life free-living conditions. The experimental results show that our framework achieves an astounding 73.48% accuracy in the fine-grained (normal, mild, moderate, severe) classification of PD severity based on hand movements. Overall, this study contributes to more accurate PD self-diagnosis in the wild, allowing doctors to provide remote drug intervention guidance.
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