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Although two-dimensional (2D) atomic layers, such as transition-metal chalcogenides, have been widely synthesized using techniques such as exfoliation.sup.1-3 and vapour-phase growth.sup.4,5, it is still challenging to obtain phase-controlled 2D structures.sup.6-8. Here we demonstrate an effective synthesis strategy via the progressive transformation of non-van der Waals (non-vdW) solids to 2D vdW transition-metal chalcogenide layers with identified 2H (trigonal prismatic)/1T (octahedral) phases. The transformation, achieved by exposing non-vdW solids to chalcogen vapours, can be controlled using the enthalpies and vapour pressures of the reaction products. Heteroatom-substituted (such as yttrium and phosphorus) transition-metal chalcogenides can also be synthesized in this way, thus enabling a generic synthesis approach to engineering phase-selected 2D transition-metal chalcogenide structures with good stability at high temperatures (up to 1,373 kelvin) and achieving high-throughput production of monolayers. We anticipate that these 2D transition-metal chalcogenides will have broad applications for electronics, catalysis and energy storage. A synthetic approach is described, for efficiently converting non-van der Waals solids into two-dimensional van der Waals transition-metal chalcogenide layers with specific phases, enabling the high-throughput production of monolayers., Author(s): Zhiguo Du [sup.1] , Shubin Yang [sup.1] , Songmei Li [sup.1] , Jun Lou [sup.2] , Shuqing Zhang [sup.3] , Shuai Wang [sup.1] , Bin Li [sup.1] , Yongji [...]

Applications in industrial production have indicated that the challenges of sparse fault samples and singular monitoring data will diminish the performance of deep learning-based diagnostic models to varying degrees. To alleviate the above issues, a multi-source information fusion meta-learning network with convolutional block attention module (CBAM) is proposed in this study for bearing fault diagnosis under limited dataset. This method can fully extract and exploit the complementary and enriched fault-related features in the multi-source monitoring data through the designed multi-branch fusion structure and incorporate metric-based meta-learning to enhance the fault diagnosis performance of the model under limited data samples. Furthermore, the introduction of CBAM can further assist the model to trade-off and focus on more discriminative information in both spatial and channel dimensions. Extensive experiments conducted on two bearing datasets that cover multi-source monitoring data fully demonstrate the validity and superiority of the proposed method. [ABSTRACT FROM AUTHOR]

[Introduction] Energy storage is an important component and key supporting technology of Energy Internet. It can provide various services such as peak shaving and frequency modulation. It is an important means to enhance the flexibility, economy and safety of traditional power system. [Method] This paper reviewed the characteristics of the existing main energy storage technologies, and analyzed the functions and requirements of energy storage at power supply side, user side and grid side. According to the status quo of application, the key issues of safety, economy and business model of energy storage are pointed out. [Result] The results show that the energy storage operation simulation, multiple combination utilization, combination of concentration and dispersion should be strengthened from the perspective of energy storage application. [Conclusion] This work provides some guidance for further study on the application research and development of energy storage technology.

The Ni60 alloy cladding layer with different La2O3 content was prepared by laser cladding technology on 35CrMoV surface. The phase composition, element distribution, micro-structure and tribological properties of the coating with different addition of La2O3 were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), Microscopic Vickers hardness tester, MicroXAM-800 optical surface photometer and friction testing machine. The results show that the main phases of the cladding layer are (Ni, Fe), CrB, CrMn, Cr7C3 and Cr23C6. The diffraction peak shifted to the left in XRD with the addition of La2O3, which indicates that there is a certain lattice distortion in the cladding phase. The microstructure of the cladding layer is refined, the friction coefficient and the depth of wear trace are decreased to varying degrees, and the wear resistance of the cladding layer is greatly improved. The results show that the addition of 1.6%La2O3 can effectively refine grain, inhibit the formation of cracks and pores, and improve the wear performance of the cladding layer. [ABSTRACT FROM AUTHOR]

Linalool is an important substance in the synthesis of fragrances owing to its unique aroma. However, the application of linalool is limited due to its low stability and rapid volatilization. Supramolecular inclusion technology plays an important role in improving the stability and volatility of fragrance and endows fragrance with excellent heat‐controlled release properties. In this study, inclusion complexes were prepared with two acyclic cucurbit[n]urils (M1 and M2) to improve the thermal stability of linalool, their binding behaviours were investigated by NMR, XRD, FT‐IR and Molecular Docking, confirming the formation of the host‐guest inclusion complexes. The stoichiometry of inclusion complexes was 1:1 by Job's plot and the binding constant was determined by fluorescence titration. The TG and heat‐controlled release experiment indicated that the inclusion complexes have higher thermal stability. This study provides a new idea and method for the development of linalool series spices. [ABSTRACT FROM AUTHOR]

In order to fully exploit the dynamic operation characteristics of absorption heat pump, a dynamic simulation model of LiBr absorption heat pump considering mass transfer and distribution parameters is established. The thermal inertia characteristics of the system are studied, and the thermal performance and crystallization characteristics of the system are analyzed under the conditions of heat source temperature change, cooling water temperature change and refrigerant water temperature change. The results show that: the model can accurately simulate the steady-state and dynamic characteristics of the absorption heat pump; the thermal inertia of the unit is mainly related to the mass of the solution stored in the unit; the upper limit of the heat source inlet temperature is affected by the COP of the system and the crystallization risk, the decrease of the inlet temperature of cooling water can increase the COP of the system, and the lower limit is limited by the crystallization risk, and the cooling water inlet temperature is affected by the crystallization risk , and the lower limit of the inlet temperature of cooling water is limited by the crystallization characteristics. The upper limit of the inlet temperature of refrigerant water is not limited by the crystallization characteristics, but is mainly limited by the user’s energy demand. This provides a reference for the dynamic operation of absorption heat pump.

Uridine diphosphate (UDP)-sugars are important metabolites involved in the biosynthesis of polysaccharides and may be important signaling molecules. UDP-glucose 4-epimerase (UGE) catalyzes the interconversion between UDP-Glc and UDP-Gal, whose biological function in rice (Oryza sativa) fertility is poorly understood. Here, we identify and characterize the botryoid pollen 1 (bp1) mutant and show that BP1 encodes a UGE that regulates UDP-sugar homeostasis, thereby controlling the development of rice anthers. The loss of BP1 function led to massive accumulation of UDP-Glc and imbalance of other UDP-sugars. We determined that the higher levels of UDP-Glc and its derivatives in bp1 may induce the expression of NADPH oxidase genes, resulting in a premature accumulation of reactive oxygen species (ROS), thereby advancing programmed cell death (PCD) of anther walls but delaying the end of tapetal degradation. The accumulation of UDP-Glc as metabolites resulted in an abnormal degradation of callose, producing an adhesive microspore. Furthermore, the UDP-sugar metabolism pathway is not only involved in the formation of intine but also in the formation of the initial framework for extine. Our results reveal how UDP-sugars regulate anther development and provide new clues for cellular ROS accumulation and PCD triggered by UDP-Glc as a signaling molecule. UDP-Glc and its derivatives induce the expression of NADPH oxidase genes, inducing ROS-triggered PCD as signaling molecules, but also regulate pollen wall development as metabolites. [ABSTRACT FROM AUTHOR]

The vibration signal of a pump is often used for analysis in the study of hydraulic-pump fault diagnosis methods. In this study, for the analysis, sound signals were used, which can be used to acquire data in a non-contact manner to expand the use scenarios of hydraulic-pump fault-diagnosis methods. First, the original data are denoised using complete ensemble empirical mode decomposition with adaptive noise and the minimum redundancy maximum relevance algorithm. Second, the noise-reduced data are plotted as mean spectrogram bar graphs, and the datasets are divided. Third, the training set graphs are input into the ResNet-50 network to train the base model for fault diagnosis. Fourth, all the layers of the base model are frozen, except for the fully connected and softmax layers, and the support set graphs are used to train the base model through transfer learning. Finally, a fault diagnosis model is obtained. The model is tested using data from two test pumps, resulting in accuracies of 86.1% and 90.8% and providing evidence for the effectiveness of the proposed method for diagnosing faults in hydraulic plunger pumps. [ABSTRACT FROM AUTHOR]