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Key message: Metabolic module, gene expression pattern and PLS modeling were integrated to precisely identify the terpene synthase responsible for sesquiterpene formation. Functional characterization confirmed the feasibility and sensitivity of this strategy. Plant secondary metabolite biosynthetic pathway elucidation is crucial for the production of these compounds with metabolic engineering. In this study, an integrated strategy was employed to predict the gene function of sesquiterpene synthase (STS) genes using turmeric as a model. Parallel analysis of gene expression patterns and metabolite modules narrowed the candidates into an STS group in which the STSs showed a similar expression pattern. The projections to latent structures by means of partial least squares model was further employed to establish a clear relationship between the candidate STS genes and metabolites and to predict three STSs (ClTPS16, ClTPS15 and ClTPS14) involved in the biosynthesis of several sesquiterpene skeletons. Functional characterization revealed that zingiberene and β-sesquiphellandrene were the major products of ClTPS16, and β-eudesmol was produced by ClTPS15, both of which indicated the accuracy of the prediction. Functional characterization of a control STS, ClTPS1, produced a small amount of β-sesquiphellandrene, as predicted, which confirmed the sensitivity of metabolite module analysis. This integrated strategy provides a methodology for gene function predictions, which represents a substantial improvement in the elucidation of biosynthetic pathways in nonmodel plants. [ABSTRACT FROM AUTHOR]

Interdecadal variability of tropical cyclone (TC) genesis in the South China Sea (SCS) during 1982–2015 is investigated using observations and atmospheric reanalysis data. TC genesis primarily occurs in the northern SCS (north of 13 °N) in July–September (summer), while in the southern SCS (south of 13 °N) in October–December (autumn). The TC genesis location is consistent with the climatological distribution of TC genesis potential index. Noticeably, the TC genesis frequency (TCGF) is relatively low in 1982–1993 and 2003–2015 while relatively high in 1994–2002 in summer in the SCS. In autumn, the TCGF shows an abrupt transition from high to low in the early 2000s in the SCS. It is found that such interdecadal change of TCGF is closely related to the east‐westward movement of the subtropical high (SH). When the SH is close to the SCS, large‐scale air subsidence, low‐level divergence, negative vorticity, and high pressure are prominent and inhabit TC genesis in the SCS. On the contrary, when the SH moves away from the SCS, environmental conditions become more favorable for TC genesis. In addition, the localized atmospheric intraseasonal variability can affect TCGF at interdecadal time scales as well. Key Points: The interdecadal variability of TCGF in the SCS is closely related to the east‐westward movement of WPSH (NASH) in summer (autumn)The east‐westward movement of SH affects TCGF in the SCS by influencing large‐scale environmentSouth China Sea, Tropical Cyclone, Interdecadal Variability, Subtropical High [ABSTRACT FROM AUTHOR]

A number of tropical cyclones (TCs) in the western North Pacific (WNP) pass through Luzon Strait (LS) into the South China Sea (SCS) from June to November every year. The monthly variability of the ratio of TC intensity change, Rtc, shows that majority of the LSTCs achieve their lifetime maximum intensity (LMI) over the northern SCS (WNP) during August-September (June-July and October-November). Furthermore, compared to August, LSTCs in September are more easily intensified, suggesting that atmospheric and/or oceanic environments over the northern SCS in September are more favorable for TC development. The monthly-averaged oceanic and atmospheric environmental factors, including sea surface temperature, upper-ocean warm layer depth, vertical wind shear, relative humidity and large-scale low-level vorticity, are compared. The comparison between August and September is mainly studied because of the higher LSTCs frequency in these 2 months. The intensification tendency of LSTCs in September is primarily attributed to the relative thick upper-ocean warm layer and weak vertical wind shear. The transition of East Asian summer monsoon to winter monsoon tends to provide more favorable environmental conditions in September than in August for TC intensification in the northern SCS. [ABSTRACT FROM AUTHOR]

The training of neural networks involves numerous operations on the weight matrix. If neural networks are implemented in hardware, all weights will be updated in parallel. However, neural networks based on CMOS technology face many challenges in the updating phase of weights. For example, derivation of the activation function and error back propagation make it difficult to be realized at the circuit level, even though the back propagation algorithm is rather efficient and popular in neural networks. In this paper, a novel synaptic unit based on double identical memristors is designed, on the basis of which a new neural network circuit architecture is proposed. The whole network is trained by a hardware-friendly weight simultaneous perturbation (WSP) algorithm. The hardware implementation of neural networks based on WSP algorithm only involves the feedforward circuit and does not require the bidirectional circuit. Furthermore, two forward calculations are merely needed to update all weight matrices for each pattern, which significantly simplifies the weight update circuit and allows simpler and easier implementation of the neural network in hardware. The practicability, utility and simplicity of this scheme are demonstrated by the supervised learning tasks. [ABSTRACT FROM AUTHOR]

This paper introduces a novel CMOS second-generation current-controlled current conveyor (CCCII) that has a wide tunable intrinsic resistance ( R x ). The designed structure is achieved by the combination of one ordinary CCCII, one cross-coupled OTA and one active resistor. An inverse relationship between the intrinsic resistance and external bias current is created for the first time in CMOS CCCII design, which results in wide tuning range of R x . Performance of the proposed circuit is discussed by detailed analysis. The CMOS CCCII is simulated in TSMC 0.18 μ m RF CMOS technology. The simulation results confirm that the proposed CMOS CCCII achieves a wide tunable R x (from 197.4 Ω to 27.23 k Ω ) while maintaining favorable performance in bandwidth, transfer gain and linear range. In addition, a new reconfigurable structure, which can function as a universal filter or a quadrature oscillator via controlling an enabled switch, is given as an application example to validate the feasibility of the proposed CMOS CCCII. [ABSTRACT FROM AUTHOR]

It is well-known that Fe3+ impurities in the electrolyte can significantly promote the oxygen evolution reaction (OER) activity of Co-based and Ni-based electrocatalysts. However, it is not clear if they work for single-metal Fe-based catalysts. Here, we systematically investigate the influence of Fe3+ ions in the electrolyte on the OER activity of core-shell FeO x @C catalytic system. We find that the absorbed Fe3+ can induce the generation of surface oxygen vacancies and regulate the electronic structure of active sites, thus increasing the OER kinetics and decreasing the energy barrier. Combining with in-situ Raman and ex-situ X-ray photoelectron spectroscopy (XPS) analysis, we disclose that Fe4+ species is the active species for the OER and positively correlate the characteristic content of the high-valence Fe species and OER activity. Fe3+ impurities in the electrolyte can improve the OER activity of Fe-based catalysts, which can be oxidized into Fe4+ as the active species. [Display omitted] • FeO x @C-700 exhibits improved OER activity when dropping Fe3+ into the electrolyte. • Fe3+ impurities have synergistic effects with FeO x @C-700. • In-situ Raman and ex-situ XPS spectra reveal Fe4+ species during the OER. • Fe4+ favors the OER as the reactive species. [ABSTRACT FROM AUTHOR]