Showing papers by "Lin Jiang published in 2022"
TL;DR: Both genetic and pharmacological inhibition of METTL3 attenuated renal injury and inflammation are identified, suggesting that theMETTL3/TAB3 axis is a potential target for treatment of AKI.
Abstract: The role of N6-methyladenosine (m6A) modifications in renal diseases is largely unknown. Here, we characterized the role of N6-adenosine-methyltransferase-like 3 (METTL3), whose expression is elevated in renal tubules in different acute kidney injury (AKI) models as well as in human biopsies and cultured tubular epithelial cells (TECs). METTL3 silencing alleviated renal inflammation and programmed cell death in TECs in response to stimulation by tumor necrosis factor–α (TNF-α), cisplatin, and lipopolysaccharide (LPS), whereas METTL3 overexpression had the opposite effects. Conditional knockout of METTL3 from mouse kidneys attenuated cisplatin- and ischemic/reperfusion (I/R)–induced renal dysfunction, injury, and inflammation. Moreover, TAB3 [TGF-β–activated kinase 1 (MAP3K7) binding protein 3] was identified as a target of METTL3 by m6A methylated RNA immunoprecipitation sequencing and RNA sequencing. The stability of TAB3 was increased through binding of IGF2BP2 (insulin-like growth factor 2 binding protein 2) to its m6A-modified stop codon regions. The proinflammatory effects of TAB3 were then explored both in vitro and in vivo. Adeno-associated virus 9 (AAV9)–mediated METTL3 silencing attenuated renal injury and inflammation in cisplatin- and LPS-induced AKI mouse models. We further identified Cpd-564 as a METTL3 inhibitor that had better protective effects against cisplatin- and ischemia/reperfusion-induced renal injury and inflammation than S-adenosyl-l-homocysteine, a previously identified METTL3 inhibitor. Collectively, METTL3 promoted m6A modifications of TAB3 and enhanced its stability via IGF2BP2-dependent mechanisms. Both genetic and pharmacological inhibition of METTL3 attenuated renal injury and inflammation, suggesting that the METTL3/TAB3 axis is a potential target for treatment of AKI. Description METTL3 promotes N6-methyladenosine modifications of TAB3 mRNA, increasing acute kidney injury in mouse models. Minimizing METTL3 N6-methyladenosine (m6A) modifications to mRNA can affect splicing, translation, and stability of transcripts, but the role of these modifications in acute kidney injury (AKI) has not been well defined. Here, Wang and colleagues identified that methyltransferase-like 3 (METTL3) was induced in human and murine AKI. METTL3 contributed to the pathogenesis of AKI through m6A modification of TAB3 [TGF-β–activated kinase 1 (MAP3K7) binding protein 3] mRNA, leading to increased stability of the transcript. The authors further identified a METTL3 inhibitor that attenuated renal injury and inflammation in mouse models of AKI when given within 24 hours of injury, suggesting that the METTL3-TAB3 axis could be a potential target in the prevention and treatment of this condition.
47 citations
TL;DR: In this paper , the occurrence and distribution of nine contaminants in riverbank groundwater and adjacent rivers (distance up to 113 m) were investigated at four sites with different lithological features and permeabilities of aquifers in a city in North China.
23 citations
TL;DR: This Letter introduces long short-term memory (LSTM) networks to learn a nonlinear dynamics model of an opto-electronic feedback loop, and applies the trained deep learning model to generate a chaotic waveform for encryption and decryption at the transmitter and receiver.
Abstract: Chaotic optical communication technology is considered as an effective secure communication technology, which can protect information from a physical layer and is compatible with the existing optical networks. At present, to realize long-distance chaos synchronization is still a very difficult problem, mainly because well-matched hardware cannot always be guaranteed between the transmitter and receiver. In this Letter, we introduce long short-term memory (LSTM) networks to learn a nonlinear dynamics model of an opto-electronic feedback loop, and then apply the trained deep learning model to generate a chaotic waveform for encryption and decryption at the transmitter and receiver. Furthermore, to improve the security, we establish a deep learning model pool which consists of different gain trained models and different delay trained models, and use a digital signal to drive chaos synchronization between the receiver and transmitter. The proposed scheme is experimentally verified in chaotic-encrypted 56-Gbit/s PAM-4 systems, and a decrypted performance below 7%FEC threshold (BER = 3.8×10-3) can be achieved over a 100-km fiber transmission.
19 citations
TL;DR: An improved power-rating balance (IPRB) control for the PV-to-bus based DPP architecture that ensures each PV submodule operate at its true maximum power point (MPP) while achieving more balanced power stress distribution and higher reliability is introduced.
Abstract: With the increase of the component number, the power stress distribution among differential power processing (DPP) converters, control implementation, system cost, and reliability become the most challenging issues for a practical photovoltaic (PV) DPP system. This article introduces an improved power-rating balance (IPRB) control for the PV-to-bus based DPP architecture that ensures each PV submodule operate at its true maximum power point (MPP) while achieving more balanced power stress distribution and higher reliability. Specifically, a submodule-level finite-state-machine-based MPP tracking is implemented to guarantee always maximum power yield, whereas a string-level power-rating balancing (PRB) control is adopted to balance the unit-maximum proceeded power by DPP converters based on the built power flow model with respect to the string current. A comprehensive comparison of advanced control strategies for PV-to-bus DPP architectures, including least power point tracking, voltage equalization (VE) based PRB control, and the proposed IPRB, has been carried out with the mission-profile-based reliability assessment under different partial shading scenarios. Component-failure-rate-based reliability analysis shows that the PV-to-bus DPP architecture with the proposed IPRB control can significantly improve the system reliability. Main simulation and experimental evaluations are carried out to verify the effectiveness of the proposed control.
19 citations
TL;DR: In this paper, a water-based solar photovoltaic-thermal (PVT) system is integrated to provide heat and electricity for a hybrid sorption thermal energy storage (TES) to recover ultra-low grade solar heat below 50°C.
14 citations
TL;DR: In this article , the authors proposed an index to quantify the strongest attack that the power system with a given wide area damping controller can tolerate, which is called as resilience margin.
Abstract: Since the cyber attack on the communication network will deteriorate the performance of wide-area damping controllers (WADCs) or even cause instability, many resilient WADCs are developed to mitigate the adverse influence of cyber attacks recently. However, there is a lack of quantitative indexes to guide the controller design in order to achieve the trade-off between attack resilience and damping performance. To address this problem, an index is proposed to quantify the strongest attack that the power system with a given WADC can tolerate, which is called as resilience margin. Firstly, the power system with a WADC subjected to cyber attack is modeled as a switching system consisting of stable and unstable subsystems. Then, based on switching system theory, the definition of resilience margin is presented. To calculate the resilience margin, the Lyapunov stability analysis is implemented on the switching power system to derive a practical calculation algorithm, which combines the bisection method and the linear matrix inequalities (LMIs) technology. The case study on the 16-machine 68-bus system with a voltage source converter based high voltage direct current system is performed. Simulation results demonstrate the effectiveness of the calculation algorithm and the significance of the resilience margin in the design of WADC.
10 citations
TL;DR: In this paper , an event-triggered based load frequency control for time-delayed power system with an open communication network is proposed to further lessen communication and computation costs while preserving a desired H∞ robust performance.
10 citations
TL;DR: This paper investigates a novel integral inequality to bound the integral terms in the derivative of the Lyapunov-Krasovskii functional to establish an adjustable and relaxed stability criterion in terms of linear matrix inequalities using the proposed inequality.
9 citations
TL;DR: In this paper , an adaptive active fault tolerance control strategy was proposed for variable-speed wind turbine (VSWT) system. But the proposed control strategy neither requires detailed system model and full state measurements, nor relies on fault detection, diagnosis and isolation techniques when the generator actuator fails.
9 citations
TL;DR: A perturbation observer-based nonlinear control (PONC) is proposed to improve the robustness of VSC-MTDC systems with OWFs and to achieve robust tracking performance, without requiring the accurate system model.
8 citations
TL;DR: In this paper , a sensorless speed controller for IM based on speed and perturbation estimation and compensation is presented, which can estimate the real rotor speed under speed varying and load changes and achieve high performance robust speed drive without using speed sensors.
01 Oct 2022
TL;DR: In this paper , the authors proposed a high step-up active switched-inductive (ASL) converter with self-voltage balancing on switches, which achieved a peak efficiency of 97.3%.
Abstract: High step-up dc–dc converters are widely used in new energy applications such as photovoltaic cell, fuel cell, dc microgrid, etc. Active switched-inductor (ASL) converter has simple operation and low stress on switches. To further increase the voltage gain, some SC (switched-capacitor)/ASL step-up converters have been proposed recently. However, these SC/ASL step-up converters have voltage oscillation on switches, which leads to the voltage stress on switches is higher than the theoretical value. In this article, a novel high step-up SC/ASL converter is proposed. Compared with other SC/ASL step-up converters, the proposed converter has lower voltage stress on the switches, output diodes, and output filter capacitors, and the efficiency is higher. In addition, the proposed converter can achieve self-voltage balancing on switches. This article analyzes the proposed converter from operation principle, continuous conduction mode (CCM) analysis, CCM operation with unbalanced inductors, input current ripple analysis, discontinuous conduction mode and boundary conduction mode analysis, switches self-voltage balancing characteristic, voltage stress, current stress, comparison analysis, and design considerations. Finally, a 200 W, 25–45 V/380 V, 50 kHz experimental prototype has been established in the laboratory to evaluate the proposed converter, which reached a peak efficiency of 97.3%.
TL;DR: Wang et al. as mentioned in this paper collected 441wiping surface samples from 95 buildings and facilities at Beijing coking plant in China and found that the concentrations of 16 US EPA priority PAHs (∑16PAHs) ranged from ND-982.16 and ND-4262.
TL;DR: In this paper , a photonics-assisted mm-wave joint radar and communication (JRC) system with a multi-Gbit/s data rate for communication function and centimeter-level range resolution for radar function is proposed.
Abstract: The joint radar and communication (JRC) system providing both large-capacity transmission and high-resolution ranging will play a pivotal role in the next-generation wireless networks (e.g., 6G and beyond) and defense applications. Here, we propose and experimentally demonstrate a novel photonics-assisted millimeter-wave (mm-wave) JRC system with a multi-Gbit/s data rate for communication function and centimeter-level range resolution for radar function. The key is the design of the intermediate-frequency (IF) JRC signal through the angle modulation of the linear frequency modulation (LFM) radar carrier using orthogonal frequency division multiplexing (OFDM) communication signal, inspired by the idea of constant-envelope OFDM (CE-OFDM). This IF angle-modulated waveform facilitates the broadband photonic frequency (phase)-multiplying scheme to generate mm-wave JRC signal with multiplied instantaneous bandwidth and phase modulation index for high-resolution LFM radar and noise-robust CE-OFDM communication. It is with fixed low power-to-average power ratio to render robustness against the nonlinear distortions. In proof-of-concept experiments, a 60-GHz JRC signal with an instantaneous bandwidth over 10-GHz is synthesized through a CE-LFM-OFDM signal encoded with a 2-GBaud 16-QAM OFDM signal. Consequently, a 1.5-cm range resolution of two-dimension imaging and an 8-Gbit/s data rate are achieved for both radar and communication functions, respectively. Furthermore, the proposed JRC system is able to achieve higher radar range resolution and better anti-noise communication, when using higher-order photonic frequency multiplying.
TL;DR: In this article , a band-rejection feedback was used to suppress the time-delay signature (TDS) measured by the optical field and intensity of a semiconductor laser under a Bragg grating.
Abstract: Chaos generation from a semiconductor laser under band-rejection optical feedback is proposed and investigated numerically and experimentally. The band-rejection feedback performs better than the conventional broadband mirror feedback in concealing the feedback delay time information measured by the time-delay signature (TDS) of optical field and intensity. In this work, the optical band-rejection filter (BRF) is built up based on the transmission of a Bragg grating. The best concealment of delay time information is achieved in the form of simultaneous TDS suppression in optical field and intensity when the BRF is negatively detuned from the free-running laser frequency. Such concealment is due to the suppression of feedback cavity modes by the band-rejection effect. The concealment prefers negative detuning frequency because the laser cavity resonance is red-shifted by optical feedback due to the antiguidance effect. The negatively detuned BRF suppresses the TDS of optical field and intensity by more than an order of magnitude than mirror feedback. The simulation results are qualitatively confirmed by the experimental measurements.
TL;DR: In this paper , the concept of functional community is defined with two meanings: (1) tighter internal coupling for better efficiency within the same community; (2) more internal transmission from source to sink nodes within the community.
Abstract: The contributions of this article include a new concept, a new question, and a new method. This article proposes the concept of functional community, which is different from conventional topological community. Functional community is defined with two meanings: (1) tighter internal coupling for better efficiency within the same community; (2) more internal transmission from source to sink nodes within the same community. Then a new question about how to detect functional communities in power grids is analyzed, and most existing algorithms are not applicable. Therefore, a new method is put forward. Corresponding to meaning 1, electrical coupling strength (ECS) is defined to replace conventional adjacency matrix; corresponding to meaning 2, power supply strength is defined and integrated with ECS to form the newly defined electrical functional strength. Based on these two changes, we apply the proposed power supply modularity as a benchmark to evaluate any partitioning of power grids. Moreover, the Newman fast algorithm is modified with power supply modularity maximization to detect functional communities in power grids. The capability of the proposed partitioning method is demonstrated via the IEEE-118, IEEE-300 bus systems, and an Italian power grid. We argue that the conventional topological modularity may exaggerate the community characteristics of power grids and is inferior to the power supply modularity in detecting some functional features in communities. The work can also give inspiration to other engineering networks for functional communities.
TL;DR: In this paper , a multiphase partitioning equilibrium (MPE) model was proposed to establish the quantitative relationship between volatile organic compounds and its various partitioning phases in soil, including solid-liquid interface adsorption phase, vapour phase and dissolved phase and vapour-solid interface adaption phase.
TL;DR: Wang et al. as discussed by the authors analyzed the effects of soil properties on the derivation of soil screening levels by using Monte Carlo simulations and found that soil factors mainly affected the inhalation exposure pathway of volatile organic compounds (VOCs).
Abstract: China issued the unified national soil screening levels (NSSLs) in 2018 to assist the regulation of contaminated sites, but the applicability of NSSLs was not thoroughly evaluated. Datasets from the National Qinghai-Tibet Plateau Scientific Data Center indicated great variability of soil organic matter (0.8-173 g/kg), soil water content (0.05-0.6), soil porosity (0.4-0.6), and soil bulk density (1.11-1.59 kg/m3). We analyzed the effects of soil properties on the derivation of SSLs by using Monte Carlo simulations. The soil factors mainly affected the inhalation exposure pathway of volatile organic compounds (VOCs). They had an effect of more than two orders of magnitude on SSLs for most selected VOCs, particularly with the parameters 0.35 > Henry's law constant > 0.1 and carbon-water distribution coefficient of >100. We compared NSSLs with the recommended SSLs assuming fifth percentile by using Monte Carlo simulations. In general, NSSLs were not sufficient to identify contaminated sites that require additional investigation in the south, central, and northwest regions but were too conservative in screening sites out that required no further action in the east and northeast regions. Our framework and findings may contribute to more scientific and effective soil quality management in other large countries.
TL;DR: In this article , a simple modulation format identification (MFI) scheme based on signal envelope flatness is proposed without requiring any training or other prior information, which achieves a 100% correct identification rate for the four modulation formats over a wide optical signal-to-noise ratio (OSNR) range.
Abstract: Modulation format identification (MFI) is a critical technology for autonomous digital coherent receivers in next-generation elastic optical networks. A novel and simple MFI scheme, to the best of our knowledge, based on signal envelope flatness is proposed without requiring any training or other prior information. After amplitude normalization and partition, the incoming polarization division multiplexed (PDM) signals can be classified into quadrature phase shift keying (QPSK), 8 quadrature amplitude modulation (QAM), 16QAM, and 64QAM signals according to envelope flatnesses R1, R2, and R3 of signals in different amplitude ranges. The feasibility of the proposed MFI scheme is first verified via numerical simulations with 28 GBaud PDM-QPSK/-8QAM/-16QAM/-64QAM signals. Only by using 4000 symbols can the proposed MFI scheme achieve a 100% correct identification rate for the four modulation formats over a wide optical signal-to-noise ratio (OSNR) range. Proof-of-concept experiments among 28 GBaud PDM-QPSK/-8QAM/-16QAM systems under back-to-back and long-haul fiber transmission links are implemented to further demonstrate the effectiveness of the proposed MFI scheme. The experimental results show that the proposed MFI scheme can obtain a 100% correct identification rate when the OSNR value of each modulation format is higher than the threshold corresponding to 7% FEC and is resilient towards fiber nonlinearities. More importantly, the proposed MFI scheme can significantly reduce computational complexity.
DOI•
TL;DR: In this article , an intelligent optical performance monitoring scheme for simultaneous modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring is proposed and experimentally demonstrated in digital coherent receivers.
Abstract: An intelligent optical performance monitoring scheme for simultaneous modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring is proposed and experimentally demonstrated in digital coherent receivers. The proposed scheme introduces convolutional neural network (CNN) to automatically extract and monitor modulation format and OSNR dependent features (the empirical distribution of intensity and differential-phase) which can be obtained after constant modulus algorithm (CMA) equalization. The experiment results show that 100% identification accuracies for all modulation formats (e.g. 28-GBaud PDM-QPSK/−8PSK/ −8QAM/−16QAM/−32QAM/−64QAM) are achieved at OSNR values are lower than the corresponding theoretical 20% FEC limit (BER = 2.4×10−2). Furthermore, under the chromatic dispersion (CD) variation from 0-ps/nm to 1200-ps/nm, the root-mean- square error (RMSE) and mean absolute error (MAE) of OSNR monitoring for all modulation formats are less than 0.0896-dB and 0.0657-dB, respectively. Subsequently, the influence of frequency offset and fiber nonlinearity effect on the intelligent optical performance monitoring scheme is also analyzed. We believe that our proposed multi-parameter monitoring scheme has the potential to be applied in the next-generation intelligent elastic optical networks.
TL;DR: In this article , the state of methane molecule adsorption on different media in marine shales is analyzed by conducting mineral composition analysis, TOC content analysis, isothermal adaption experiments, FIB-SEM, and FIBHIM experiments on the core samples referring to previous research.
Abstract: The major sedimentary basins in China contain abundant shale gas resources to be explored, and the exploration of shale gas has received more attention in recent years. Shale gas exists mainly in two states, i.e., free and adsorbed. The latter mainly exists on the surface of media, including organic matter and clay minerals, etc., but its adsorption state remains unknown. In this paper, we take the Longmaxi Formation marine shale in the southern Sichuan Basin of southern China as the research object. The state of methane molecule adsorption on different media in marine shales is analyzed by conducting mineral composition analysis, TOC content analysis, isothermal adsorption experiments, FIB-SEM, and FIB-HIM experiments on the core samples referring to previous research. The conclusions are as follows: the adsorbed gas mainly exists in the organic-matter pores, which feature excellent roundness and connectivity with a large number of small pores inside like a hive. The surface of the organic matter contains many adsorption sites, featuring strong adsorption capacity and making methane molecules continuously distributed on the internal surface of the organic-matter pores. The organic matter has a large specific surface area and is lipophilic, which offers an ideal condition for the adsorption of methane molecules. Part of the adsorbed gas exists in the pores of clay minerals, which are lamellar and triangular. The surface of clay minerals contains fewer adsorption sites, featuring poorer adsorption capacity and making methane molecules discontinuously distributed on the surface of the clay minerals. The clay minerals have a smaller specific surface area than the organic matter, thus featuring a smaller space for adsorption. The clay minerals are hydrophilic. In addition to methane molecules, mixed-layer illite/smectite (I/S) and chlorite also adsorb water molecules. The illite surface adsorbs mainly water molecules and, to a lesser extent, methane molecules. Finally, the adsorption state patterns of methane molecules on organic matter and clay minerals were summarized.
TL;DR: In this article , a new Lyapunov functional with several augmented terms, including extra free matrices and overflow nonlinear function, is constructed such that it has a relaxed positive condition.
Abstract: This paper is concerned with the stability analysis of fixed-point state-space digital filters with generalized overflow arithmetic and a time-varying delay. This paper aims to derive a delay and nonlinear function bound dependent asymptotical stability criterion with less conservatism. Firstly, a new Lyapunov functional with several augmented terms, including extra free matrices and overflow nonlinear function, is constructed such that it has a relaxed positive condition. Then, for bounding the summation term arising in the forward difference of Lyapunov functional, a new lemma is developed to introduce the terms for linking the delayed states and the overflow nonlinear function, the Wirtinger-based summation inequality and several zero-value terms are applied to add more cross terms. As a result, a stability criterion with less conservatism is established and its conservatism. Finally, several numerical examples are given to illustrate the advantages of the proposed method.
TL;DR: P1-like PPs were very similar and conserved based on gene content similarities, with only eight highly variable regions, and two kinds of replicon types, namely, IncY and p0111, were identified and can be used to specifically identify the P1- like phage.
Abstract: As a PP, P1 DNA exists as a low-copy-number plasmid and replicates autonomously with a lysogenization style. This unique mode of P1-like elements probably indicates a stable contribution to antibiotic resistance. ABSTRACT The P1-like phage plasmid (PP) has been widely used as a molecular biology tool, but its role as an active accessory cargo element is not fully understood. In this study, we provide insights into the structural features and gene content similarities of 77 P1-like PPs in the RefSeq database. We also describe a P1-like PP carrying a blaCTX-M-55 gene, JL22, which was isolated from a clinical strain of Escherichia coli from a duck farm. P1-like PPs were very similar and conserved based on gene content similarities, with only eight highly variable regions. Importantly, two kinds of replicon types, namely, IncY and p0111, were identified and can be used to specifically identify the P1-like phage. JL22 is similar to P1, acquiring an important foreign DNA fragment with two obvious features, namely, the plasmid replication gene repA′ (p0111) replacing the gene repA (IncY) and a 4,200-bp fragment mobilized by IS1380 and IS5 and containing a blaCTX-M-55 gene and a trpB gene encoding tryptophan synthase (indole salvaging). The JL22 phage could be induced but had no lytic capacities. However, a lysogenic recipient and intact structure of JL22 virions were observed, showing that the extended-spectrum β-lactamase blaCTX-M-55 gene was successfully transferred. Overall, conserved genes can be a good complement to improve the identification efficiency and accuracy in future screening for P1-like PPs. Moreover, the highly conserved structures may be important for their prevalence and dissemination. IMPORTANCE As a PP, P1 DNA exists as a low-copy-number plasmid and replicates autonomously with a lysogenization style. This unique mode of P1-like elements probably indicates a stable contribution to antibiotic resistance. After analyzing these elements, we show that P1-like PPs are very similar and conserved, with only eight highly variable regions. Moreover, we observed the occurrence of replicon IncY and p0111 only in the P1-like PP community, implying that these conserved regions, coupled with IncY and p0111, can be an important complement in future screening of P1-like PPs. Identification and characterization of JL22 confirmed our findings that major changes were located in variable regions, including the first detection of blaCTX-M-55 in such a mobile genetic element. This suggests that these variable regions may facilitate foreign DNA mobilization. This study features a comprehensive genetic analysis of P1-like PPs, providing new insights into the dissemination mechanisms of antibiotic resistance through P1 PPs.
01 May 2022
TL;DR: In this article , the performance of single-mode fibers based on probabilistically-shaped 16QAM has been experimentally demonstrated and the BER results after adaptive chromatic dispersion and nonlinearity compensation are lower than 25% FEC threshold for all C-band channels.
Abstract: Transmission capacity of 28.224-Tbit/s over 8191.898-km single-mode fibers based on probabilistically-shaped 16QAM has been experimentally demonstrated. The BER results after adaptive chromatic dispersion and nonlinearity compensation are lower than 25%FEC threshold for all C-band channels.
TL;DR: In this paper , the authors proposed a resonant converter with hybrid modulation, which can realize a wide output voltage range, in a narrow switching frequency range with excellent soft-switching performance.
Abstract: Commonly used lithium‐ion battery on‐board charger (OBC) for electric vehicles (EVs) needs a wide output voltage range, but the traditional LLC converter is hard to meet the need under the condition of high efficiency and high power density. In this paper, a resonant converter with hybrid modulation is proposed. The converter has a relatively simple topology and control method. Compared with the traditional LLC topology, only two diodes are replaced by MOSFETs on the secondary side of the transformer, and no auxiliary components are added. The primary‐side switches adopt PFM) and the secondary‐side switches adopt short‐circuit control in the proposed converter, which can realize a wide output voltage range, in a narrow switching frequency range with excellent soft‐switching performance. The proposed converter can effectively reduce the resonant current and the volume of transformer core and achieve energy delivery with high power density and high efficiency. The operation principles, voltage gain, and soft‐switching conditions of the converter are analyzed in this paper. Finally, a 3.3‐kW SiC‐based prototype with 400‐V input and 250‐ to 430‐V output is built to verify the feasibility and validity of the proposed converter.
TL;DR: The present study aims to establish an optimal dose and provide a PK/PD Cutoff value (COPD) for cefquinome against S. aureus based on ex vivo pharmacokinetics and pharmacodynamics (PK/PD) integration, and contribute to the rational use of cefchinome for mastitis treatment in clinical veterinary medicine.
Abstract: Cefquinome, the fourth-generation cephalosporin applied solely for veterinary medicine, is commonly used for bovine mastitis caused by Staphylococcus aureus. The present study aims to establish an optimal dose and provide a PK/PD Cutoff value (COPD) for cefquinome against S. aureus based on ex vivo pharmacokinetics and pharmacodynamics (PK/PD) integration. This study investigated the pharmacokinetics (PK) of cefquinome when administered as three consecutive intramammary (IMM) doses of cefquinome in three healthy dairy cows at 75 mg/gland. Drug concentration was determined by HPLC-MS/MS assay. The ex vivo pharmacodynamics (PD) of cefquinome were evaluated by using a milk sample from a PK experiment. The relationship between the AUC/ MIC of cefquinome and bacterial loading reduction was simulated using a Sigmoid Emax model. The cefquinome concentration in milk attained a maximum level of 1.55 ± 0.21 mg/mL at 1.8 h after the third administration. The mean value of the area under the concentration-time curve (AUC0−24) was 26.12 ± 2.42 mg·h/mL after the third administration. The elimination half-life was 10.6 h. For PD profile, the MICs of cefquinome in milk were 2–4 times higher than those in the broth. In vitro time-killing curve shows that initial bacterial concentration has a huge impact on antibacterial effect on three strains. The antibacterial effect was weakened with the initial bacterial concentration increasing from 106 to 108 CFU/mL. The AUC0−24h/MIC index correlated well with ex vivo efficacy both for the initial inoculum of 106 CFU/mL and 108 CFU/mL (R2 > 0.84). According to the inhibitory sigmoid Emax model analysis, the PK/PD surrogate (AUC0−24/MIC) values were 8,638, 1,397, and 3,851 for bactericidal effect (E = −3) with an initial inoculum of 106 CFU/mL, while the corresponding values were 12,266, 2,295, and 5,337, respectively, with the initial inoculum of 108 CFU/mL. The ex vivo PK/PD based population dose prediction indicated a target attainment rate (TAR) of 90% of 55 mg/gland/12 h. The COPD for cefquinome against S. aureus was 2 μg/mL under the recommended dose of 55 mg/gland/12 h. However, it should be validated in clinical practice in future investigations. These results contribute to the rational use of cefquinome for mastitis treatment in clinical veterinary medicine.
TL;DR: Wang et al. as discussed by the authors developed a 3D gas accumulation facility that can reflect the high temperature and pressure under the geological condition to simulate the gas accumulation process in the tight formation of the Jurassic Formation, Sichuan Basin.
Abstract: Although significant progress has been made in tight gas exploration and development, there is still a limited understanding of the gas accumulation mechanism in tight formation. The description of heterogeneity in the tight reservoir is still an obstacle during tight gas exploration. In this work, we will develop a 3D gas accumulation facility that can reflect the high temperature and pressure under the geological condition to simulate the gas accumulation process in the tight formation of the Jurassic Formation, Sichuan Basin. Both the physical experiment simulation and numerical simulation methods will be combined to reveal the mechanism of gas accumulation. The results show that (1) the permeability ratio can characterize the heterogeneity of tight reservoirs. Based on this parameter, petroleum geologists can understand the interlayer heterogeneity during fluvial deposition and predict the sweet spots of tight gas; (2) the permeability ratio relationship between hydrocarbon accumulation of the tight sandstone reservoir mainly manifests as long as there is the existence of the differential permeability and there will be differences in natural gas migration dynamics, so that the natural gas accumulates in pores and depends on the extent of source rock; and (3) although the difference between capillary force curves is at the core of the influence of the permeability ratio on the gas-bearing capacity of the “sweet spot” sand body, the permeability ratio is a parameter of practical engineering significance. This work adds new methods to tight gas formation heterogeneity characterization and sheds light on the mechanisms of hydrocarbon accumulation in tight formation.
TL;DR: In this paper , a zero-mode equivalent circuit that can reflect the transformer winding arrangement structure and sympathetic interaction is proposed for mechanism analysis and further simulation analysis also reveals sympathetic interaction may lead to the long-delay zero-sequence backup protection malfunction of the upstream line of the operating transformer.
TL;DR: In this article , a model construction scheme of chaotic optoelectronic oscillator (OEO) based on the Fourier neural operator (FNO) is proposed, which learns the nonlinear dynamics of OEO (actual components) in a data-driven way, expecting to obtain a multi-parameter OEO model for generating chaotic carrier with high efficiency and low cost.
Abstract: A model construction scheme of chaotic optoelectronic oscillator (OEO) based on the Fourier neural operator (FNO) is proposed. Different from the conventional methods, we learn the nonlinear dynamics of OEO (actual components) in a data-driven way, expecting to obtain a multi-parameter OEO model for generating chaotic carrier with high-efficiency and low-cost. FNO is a deep learning architecture which utilizes neural network as a parameter structure to learn the trajectory of the family of equations from training data. With the assistance of FNO, the nonlinear dynamics of OEO characterized by differential delay equation can be modeled easily. In this work, the maximal Lyapunov exponent is applied to judge whether these time series have chaotic behavior, and the Pearson correlation coefficient (PCC) is introduced to evaluate the modeling performance. Compare with long and short-term memory (LSTM), FNO is not only superior to LSTM in modeling accuracy, but also requires less training data. Subsequently, we analyze the modeling performance of FNO under different feedback gains and time delays. Both numerical and experimental results show that the PCC can be greater than 0.99 in the case of low feedback gain. Next, we further analyze the influence of different system oscillation frequencies, and the generalization ability of FNO is also analyzed.