Aero-Engine Remaining Useful Life Prediction Based on Bi-Discrepancy Network.

Most unsupervised domain adaptation (UDA) methods align feature distributions across different domains through adversarial learning. However, many of them require introducing an auxiliary domain alignment model, which incurs additional computational costs. In addition, they generally focus on the global distribution alignment and ignore the fine-grained domain discrepancy, so target samples with significant domain shifts cannot be detected or processed for specific tasks. To solve these problems, a bi-discrepancy network is proposed for the cross-domain prediction task. Firstly, target samples with significant domain shifts are detected by maximizing the discrepancy between the outputs of the dual regressor. Secondly, the adversarial training mechanism is adopted between the feature generator and the dual regressor for global domain adaptation. Finally, the local maximum mean discrepancy is used to locally align the fine-grained features of different degradation stages. In 12 cross@-domain prediction tasks generated on the C-MAPSS dataset, the root-mean-square error (RMSE) was reduced by 77.24%, 61.72%, 38.97%, and 3.35% on average, compared with the four mainstream UDA methods, which proved the effectiveness of the proposed method.

A Novel Sodium-Potassium Anode Supported by Fluorinated Aluminum Foam.

Sodium-potassium (NaK) liquid alloy is a promising candidate for use as an anode material in sodium batteries because of its fluidity, which effectively suppresses the growth of sodium or potassium dendrites. However, the poor wettability of NaK alloy on conventional metal substrates is unfavorable for cell fabrication due to its strong surface tension. In this paper, low-density and low-cost fluorinated aluminum foam is used as a substrate support material for NaK liquid alloy. By combining low-surface-tension NaKC with fluorinated aluminum foam, we obtain a uniformly distributed and structurally stable electrode material. The composite electrode has a cycling stability of more than 3000 h in a symmetrical cell. Furthermore, when coupled with a sulfurized polyacrylonitrile cathode in carbonate electrolyte, it maintains excellent stability even after 800 cycles, with 72% of capacity retention.

DnFCA Isoforms Cooperatively Regulate Temperature-Related Flowering in Dendrobium nobile.

Timely flowering is a determinative trait for many economically valuable species in the Dendrobium genus of the Orchidaceae family, some of which are used for ornamental and medicinal purposes. D. nobile, a representative species of nobile-type Dendrobium, normally flowers in spring after exposure to sufficient low temperatures in winter. However, flowering can be stopped or disrupted by the untimely application of high temperatures. Little is known about the regulation and the mechanisms behind this switch. In this study, we report two isoforms from the KFK09_017173 locus of the D. nobile genome, named DnFCAγ and DnFCAß, respectively, that cooperatively regulate flowering in D. nobile. These two isoforms are generated by alternative 3' polyadenylation of DnFCA (FLOWERING CONTROL LOCUS C in D. nobile) pre-mRNA and contain a distinct 3'-terminus. Both can partially rescue late flowering in the Arabidopsis fca-1 mutant, while in wild-type Arabidopsis, they tend to delay the flowering time. When introduced into the detached axillary buds or young seedlings of D. nobile, both were able to induce the transcription of DnAGL19 (AGAMOUS LIKE 19 in D. nobile) in seedlings, whereas only DnFCAγ was able to suppress the transcription of DnAPL1 (AP1-LIKE 1 in D. nobile) in axillary buds. Furthermore, the time-course change of DnFCAγ accumulation was opposite to that of DnAPL1 in axillary buds, which was remarkable under low temperatures and within a short time after the application of high temperatures, supporting the suggestion that the expression of DnAPL1 can be inhibited by a high accumulation of DnFCAγ in floral buds. In leaves, the accumulation of DnFCAß was in accordance with that of DnAGL19 and DnFT (FLOWERING LOCUS T in D. nobile) to a large extent, suggesting the activation of the DnAGL19-DnFT pathway by DnFCAß. Taken together, these results suggest that the DnFCAγ-DnAPL1 pathway in axillary buds and the DnFCAß-DnAGL19 pathway in the leaves cooperatively promote flowering under low temperatures. The long-term and constant, or untimely, application of high temperatures leads to the constitutive suppression of DnAPL1 by a high level of DnFCAγ in axillary buds, which consequently delays floral development.

Spatial Resolution Limit for Nanoindentation Mapping on Metallic Glasses.

Spatial heterogeneity, as a crucial structural feature, has been intensively studied in metallic glasses (MGs) using various techniques, including two-dimensional nanoindentation mapping. However, the limiting spatial resolution of nanoindentation mapping on MGs remains unexplored. In this study, a comprehensive study on four representative MGs using nanoindentation mapping with a Berkovich indenter was carried out by considering the influence of a normalized indentation spacing d/h (indentation spacing/maximum indentation depth). It appeared to have no significant correlation with the measured hardness and elastic modulus when d/h > 10. The hardness and elastic modulus started to increase slightly (up to ~5%) when d/h < 10 and further started to decrease obviously when d/h < 5. The mechanism behind these phenomena was discussed based on a morphology analysis of residual indents using scanning electron microscopy and atomic force microscopy. It was found that the highest spatial resolution of ~200 nm could be achieved with d/h = 10 using a typical Berkovich indenter for nanoindentation mapping on MGs, which was roughly ten times the curvature radius of the Berkovich indenter tip (not an ideal triangular pyramid) used in this study. These results help to promote the heterogeneity studies of MGs using nanoindentation that are capable of covering a wide range of length scales with reliable and consistent results.

Folded network and structural transition in molten tin.

The fundamental relationships between the structure and properties of liquids are far from being well understood. For instance, the structural origins of many liquid anomalies still remain unclear, but liquid-liquid transitions (LLT) are believed to hold a key. However, experimental demonstrations of LLTs have been rather challenging. Here, we report experimental and theoretical evidence of a second-order-like LLT in molten tin, one which favors a percolating covalent bond network at high temperatures. The observed structural transition originates from the fluctuating metallic/covalent behavior of atomic bonding, and consequently a new paradigm of liquid structure emerges. The liquid structure, described in the form of a folded network, bridges two well-established structural models for disordered systems, i.e., the random packing of hard-spheres and a continuous random network, offering a large structural midground for liquids and glasses. Our findings provide an unparalleled physical picture of the atomic arrangement for a plethora of liquids, shedding light on the thermodynamic and dynamic anomalies of liquids but also entailing far-reaching implications for studying liquid polyamorphism and dynamical transitions in liquids.

Two-way tuning of structural order in metallic glasses.

Metallic glasses are expected to have quite tunable structures in their configuration space, without the strict constraints of a well-defined crystalline symmetry and large energy barriers separating different states in crystals. However, effectively modulating the structure of metallic glasses is rather difficult. Here, using complementary in situ synchrotron x-ray techniques, we reveal thermal-driven structural ordering in a Ce65Al10Co25 metallic glass, and a reverse disordering process via a pressure-induced rejuvenation between two states with distinct structural order characteristics. Studies on other metallic glass samples with different compositions also show similar phenomena. Our findings demonstrate the feasibility of two-way structural tuning states in terms of their dramatic ordering and disordering far beyond the nearest-neighbor shells with the combination of temperature and pressure, extending accessible states of metallic glasses to unexplored configuration spaces.

Na⁺/K⁺ Hybrid Battery Based on a Sulfurized Polyacrylonitrile Cathode.

Sulfurized polyacrylonitrile (SPAN) nanocomposites were synthesized and used as a cathode in a novel rechargeable Na⁺/K⁺ hybrid battery with high performance for the first time. When 0.9 mol NaPF6 and 0.1 mol KPF6 were dissolved in ethylene carbonate (EC)/dimethyl carbonate(DMC)/ethyl methyl cabonate(EMC) (4:3:2, v/v/v), used as hybrid electrolyte, Na foil was used as the anode, and SPAN composites were used as the cathode, a hybrid ion system was created via composition⁻decomposition between Na⁺/K⁺ and SPAN and stripping⁻depositing of Na⁺ with suppressed dendrites by taking advantage of the self-healing electrostatic shield effect. As a result, a highly reversible calculated capacity of 1405.5 mAh gsulfur-1 with a coulombic efficiency approaching 100% after 100 cycles was obtained at a current density of 35 mA g-1. This environmentally benign, low-cost Na⁺/K⁺ hybrid battery shows promise as a new future flexible energy storage system (ESS) technology.

Using open-tubular capillary electrochromatography with part-coating column for binding constants determination of ß2 -adrenergic receptor with seven drugs.

An open-tubular capillary electrochromatography method has been developed for the determination of binding constants between ß2 -adrenergic receptor (ß2 -AR) and seven drugs. ß2 -AR was oriented immobilized onto one part of inner surface of capillary via microwave-assisted technical synthesis. According to the linear relationship between coating length and the apparent mobility of analyte, the binding constant (Kb ) can be obtained by related theories and equations. The order of Kb values between drugs such as adrenaline hydrochloride, norepinephrine bitartrate, and propranolol hydrochloride with ß2 -AR is well consistent with that reported in the literature. By the method, Kb values between four extracts of Radix Paeoniae Rubra and ß2 -AR were also successfully obtained. Subsequently, computer models were applied to interpret the CEC experiments. And the results proved to be in good agreement with the method. The work, herein, demonstrates the potential of the method in drug-receptor affinity interactions evaluation and screening of lead compounds from natural sources.

Traditional Chinese medicine syndrome-related herbal prescriptions in treatment of malignant tumors.

OBJECTIVE: To investigate the distribution characteristics of TCM syndromes and the related herbal prescriptions for malignant tumors (MT). METHODS: A clinical database of the TCM syndromes and the herbal prescriptions in treatment of 136 MT patients were established. The data were then analyzed using cluster and frequency analysis. RESULTS: According to the cluster analysis, the TCM syndromes in MT patients mainly included two patterns: deficiency of both Qi and Yin and internal accumulation of toxic heat. The commonly-prescribed herbs were Huangqi (Astraglus), Nüzhenzi (Fructus Ligustri Lucid), Lingzhi (Ganoderma Lucidum), Huaishan (Dioscorea Opposita), Xiakucao (Prunella Vulgaris), and Baihuasheshecao (Herba Hedyotidis). CONCLUSION: Deficiency of Qi and Yin is the primary syndrome of MT, and internal accumulation of toxic heat is the secondary syndrome. The herbs for Qi supplementation and Yin nourishment are mainly used, with the assistance of herbs for heat-clearance and detoxification.