Nano-control synthesis the porous network of NiCoP and F doped NiCo2Al-LDHs@ZnFeAl-LDHs nanosheets as superior catalyst for efficient overall water splitting

Zhiqiang Hou,Yujiao Zhu,Wenjuan Du,Xiangkun Jia,Tiantian Huang,Ke-Jing Huang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.112 No.-

Design and development superior electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to future construct a efficient overall water electrolyzer is imperative to relieve energy crisis. Herein, three-dimensional porous network of NiCoP nanosheets being covered by bimetallic phosphides nanoparticles with a ultra-small size of ∼ 7 nm anchored on nickel foam (NF) is synthesized via employing a low-cost hydrothermal and phosphorization reaction, which provides the numerous electrcatalytic active area and reactive sites, benefiting for HER behaviors. Additionally, a top-down structure of F-doped NiCo2Al-LDHs@ZnFeAl-LDHs (F-NC2AL@ZFAL) catalysts supported on NF is also fabricated by a two-step hydrothermal reaction, which could also provide promising OER performances. As expected, the as-prepared HER and OER catalysts manifest the lower overpotential of 58 and 177 mV at 10 mA cm−2 in 1 M KOH solution. Significantly, a overall water electrolyzer assembled by employing the as-prepared HER and OER catalysts displays the various cell voltages of 1.36, 1.55, 1.66, and 1.75 V at the corresponding current densities of 10, 20, 50, and 100 mA cm−2, with the excellent durability for 22 h at 100 mA cm−2. The favorable electrocatalytic behaviors imply the great potential of as-prepared electrocatalysts for overall water splitting.

Rapid warning of wind turbine blade icing based on MIV-tSNE-RNN

Zhiqiang Zhang,Bin Fan,Yong Liu,Peng Zhang,Jianguo Wang,Wenliang Du 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

A fast early warning algorithm for wind turbine blade icing based on a RNN model is proposed. Through wind turbine blade history data and labels as model input, the evaluation of raw m-dimension data through mean impact value (MIV) indices eliminates data with an MIV index of less than one; the remaining n-dimension data is reduced to x-dimension by the tSNE method; dimensional data is inputted into the RNN, and the model output is the icing state of the wind turbine blade in a certain future period. Based on the SCADA data from a wind field, the model was verified by an example. Using a certain example case, if the model training data is 10 4 orders of magnitude, using the MIV-tSNE-RNN algorithm, the prediction accuracy can reach approximately 72 %; compared with the RNN model, the prediction accuracy is improved by approximately 150 % while reducing the algorithm running time by approximately 45 %. If the amount of data exceeds 10 4 orders of magnitude, using the MIVtSNE-RNN algorithm, the prediction accuracy is improved by approximately 100 %. This algorithm can provide accurate and rapid prediction results for wind turbine blade icing according to actual needs.

Response variability of juvenile hormone and juvenile hormone analogs in workers of the Formosan subterranean termite (Coptotermes formosanus Shiraki)

He Du,Shijun Zhang,Yong Chen,Yunling Ke,Shi Chen,Xueyi Huang,Zhiqiang Li 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

Juvenile hormone (JH) or juvenile hormone analog (JHA) can induce soldier formation in termites. However, different studies have yielded inconsistent results on the effects of JHA on soldier production in Coptotermes formosanus Shiraki. Using filter paper as the testing substrate, the effects of JH III, pyriproxyfen and methoprene on the intact filter paper left, worker mortality and presoldier formation were tested on six colonies. Our results showed that pyriproxyfen and methoprene were more repellent than JH III. No significant difference in toxicity was observed among methoprene, pyriproxyfen and JH III. JH III and pyriproxyfen did not cause workers to differentiate into presoldiers, but methoprene can induce formation of presoldiers. Colony response variability to methoprene was observed. The confirmation of the effects of JH/JHA on C. formosanus establishes the foundation for molecular studies of soldier differentiation in this species.

Research on the Sleeve Grouting Fullness Testing of Prefabricated Structures Based on Piezoelectric Method

Yongxiao Du,Xiaoli Sun,Jun Yang,Zhiqiang Wu,Decun Bian 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.5

The traditional methods for testing the sleeve grouting fullness of prefabricated structures generally face the technical challenges such as high detection cost and inability to detect in real-time. In order to solve these technical challenges, the detection method and instrument based on the piezoelectric testing principle were developed. Through the electrical properties tests of grouting materials and grouting-leakage cycle tests of transparent sleeves, the effectiveness of the piezoelectric method for testing grout leakage defects was analyzed. The research results indicate that measuring the voltage changes before and after the piezoelectric sensor is wrapped in the grouting slurry can effectively evaluate the sleeve grouting fullness. The voltage measured by the piezoelectric sensor is significantly reduced after the sensor is wrapped in the grouting material (full grouting). Then the voltage increases after grouting leakage (insufficient grouting), and decreases again after supplementary grouting (full grouting). Moreover, whether the piezoelectric sensor is placed horizontally or vertically, the voltage shows obvious changes, indicating that the piezoelectric method is less affected by the sensor laying mode. Considering that the vertical embedding method is more stable for piezoelectric data, it is recommended to use the vertical laying mode in engineering projects. Furthermore, through the prefabricated model tests, the threshold for judging grouting fullness using piezoelectric method was determined. The test results show that the threshold for determining the grouting fullness using piezoelectric method can be set to 0.40. That is to say, when the voltage value is less than 0.40, it can be determined as complete grouting, otherwise it can be determined as insufficient grouting. The case studies results indicate that the piezoelectric method meets the quality control requirements during the grouting process of prefabricated structural sleeves. The research results provide a new approach and practical reference for solving the quality detection problem of sleeve grouting.

Diagnosis of rolling element bearing based on multifractal detrended fluctuation analyses and continuous hidden markov model

Hongchao Wang,Zhiqiang Guo,Wenliao Du 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

The conventional signal processing based methods are difficult to achieve satisfactory results for rolling element bearings (REBs)’ weak fault due to the serious influence of interference signal. Intelligent classification technology and the arising popular monitoring technology-performance evaluation assessment (PDA) are the research hotspots of fault diagnosis of REB in recent years, which could resolve the above problem to some extent. Especially the latter could reflect the operating status of the equipment more comprehensively. Effective feature extraction basing on signal processing methods and intelligent algorithm are the two key aspects for the above two technologies which will determine their effectiveness to great extent. Multifractal detrended fluctuation analyses (MDFA) is an effective non-stationary signal processing method which could reveal the multifractality buried in nonlinear and nonstationary vibration signals of REB, and continuous hidden markov model (CHMM) is a mature intelligent algorithm with solid theoretical basis and rich mathematical structure. So a diagnosis method basing on combination of MDFA with CHMM is proposed in the paper, and it could deal with both fault classification and PDA tasks for the diagnosis of REBs. Effectiveness of the proposed method is validated by two different diagnosis experiments, one for fault classification and another for lifecycle performance evaluation of REBs. Compared to state-of-the-art peer methods, the proposed method has the best performance when dealing with fault diagnosis tasks for REBs.

Improvement of the catalytic performance of immobilized penicillin acylase through assembly of macromolecular reagents in nanopore to create a crowding environment

Cheng Zhou,Anming Wang,Zhiqiang Du,Shemin Zhu,Shubao Shen 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.4

Macromolecular reagents were co-assembled with penicillin acylase (PA) and immobilized in mesocellular siliceous foams (MCFs) to resemble living cells. Types and concentrations of macromolecules were studied. The catalytic characteristic and stability of PA preparations were also investigated. PA assembled with dextran 10 k in MCFs showed maximum specific activity, 1.32-fold of that of the solely immobilized PA. The optimum pH of dextran and BSA derivatives shifted to neutrality, and the optimum temperature increased by 10 oC. Also, Km of BSA derivative of PA declined 56.7% compared to solely immobilized PA, while the Kcat/Km of PA assembled with BSA was enhanced to 147%. After incubation at 50℃ for 6 h, residual activity of PA assembled with BSA exhibited 53.0%. The ficoll derivative showed 82.8% of its initial activity at 4 oC after 8-week storage. The results indicated that macromolecular reagents assembled with PA in MCFs could dramatically improve the catalytic performance and stability of im- mobilized enzyme.

Robot Subgoal-guided Navigation in Dynamic Crowded Environments with Hierarchical Deep Reinforcement Learning

Tianle Zhang,Zhen Liu,Zhiqiang Pu,Jianqiang Yi,Yanyan Liang,Du Zhang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.7

Although deep reinforcement learning has recently achieved some successes in robot navigation, there are still unsolved problems. Particularly, a robot guided by a distant ultimate goal is easy to get stuck in danger or encounter collisions in dynamic crowded environments due to the lack of long-term perspectives. In this paper, a novel subgoal-guided approach based on two-level hierarchical deep reinforcement learning with spatial-temporal graph attention networks (ST-GANets), called SG-HDRL, is proposed for a robot navigating in a dynamic crowded environment with autonomous obstacles, e.g., crowd. Specifically, the high-level policy, that models the spatialtemporal relation between the robot and the obstacles using the obstacles’ trajectories by the designed high-level ST-GANet, generates intermediate subgoals from a longer-term perspective over higher temporal scales. The subgoals give a favorable and collision-free direction to avoid encountering danger or collisions while approaching the ultimate goal. The low-level policy, that similarly implements the designed low-level ST-GANet to implicitly predict the obstacles’ motions, takes the subgoals as short-term guidance through an intrinsic reward incentive to generate primitive actions for the robot. Simulation results demonstrate that SG-HDRL using ST-GANets has better performances compared with state-of-the-art baselines. Furthermore, the proposed SG-HDRL is deployed to an experimental platform based on omnidirectional cars, and experiment results validate the effectiveness and practicability of the proposed SG-HDRL.

Influence of synthesis parameters on phase evolution and micromorphology of lanthanum hexaaluminate

Xiaoao Li,Jianjiang Xin,,Chao Chen,Zhiqiang Du,Haotian Wang 한양대학교 세라믹연구소 2022 Journal of Ceramic Processing Research Vol.23 No.2

Lanthanum hexaaluminate is a potential candidate for thermal barrier coatings due to its unique lamellar structure andexcellent thermophysical properties. In this work, lanthanum hexaaluminate was prepared by a solid-state reaction synthesisat 1600 oC, and the effects of aluminum source type and molding method on the phase composition and microstructure of thepowder were studied. It can be seen that the synthesis efficiency of alumina as aluminium source is higher than that ofaluminium hydroxide. However, the flake structure is more obvious when aluminium hydroxide is used to synthesizealuminium hydroxide. In addition, the process of compacting green compact can effectively improve the synthesis efficiencyof LaAl11O18, but it will also affect the formation and growth of grains. Consequently, a high yield of LaAl11O18 powder witha particle size of 3 μm and aspect ratio of 9.88 can be obtained by compacting aluminum hydroxide as the aluminum source.

Alternative Biological Material for Tissue Engineering of the Vagina: Porcine-Derived Acellular Vaginal Matrix

Tian Yanpeng,Liu Yibin,Xiao Yanlai,Li Zhongkang,Zhang Mingle,Chen Liang,Li Zhen,Zhang Wangchao,Zhang Zhiqiang,Kong Desheng,Meng Li,Du Yanfang,Zhang Jingkun,Gao Jingui,Huang Xianghua 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.2

Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a severe congenital disorder characterized by vaginal hypoplasia caused by dysplasia of the Müllerian duct. Patients with MRKH syndrome often require nonsurgical or surgical treatment to achieve satisfactory vaginal length and sexual outcomes. The extracellular matrix has been successfully used for vaginal reconstruction. Methods: In this study, we developed a new biological material derived from porcine vagina (acellular vaginal matrix, AVM) to reconstruct the vagina in Bama miniature pigs. The histological characteristics and efficacy of acellularization of AVM were evaluated, and AVM was subsequently transplanted into Bama miniature pigs to reconstruct the vaginas. Results: Macroscopic analysis showed that the neovaginas functioned well in all Bama miniature pigs with AVM implants. Histological analysis and electrophysiological evidence indicated that morphological and functional recovery was restored in normal vaginal tissues. Scanning electron microscopy showed that the neovaginas had mucosal folds characteristics of normal vagina. No significant differences were observed in the expression of CK14, HSP47, and α-actin between the neovaginas and normal vaginal tissues. However, the expression of estrogen receptor (ER) was significantly lower in the neovaginas than in normal vaginal tissues. In addition, AVM promoted the expression of β-catenin, c-Myc, and cyclin D1. These results suggest that AVM might promotes vaginal regeneration by activating the β-catenin/c-Myc/cyclin D1 pathway. Conclusion: This study reveals that porcine-derived AVM has potential application for vaginal regeneration. Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a severe congenital disorder characterized by vaginal hypoplasia caused by dysplasia of the Müllerian duct. Patients with MRKH syndrome often require nonsurgical or surgical treatment to achieve satisfactory vaginal length and sexual outcomes. The extracellular matrix has been successfully used for vaginal reconstruction. Methods: In this study, we developed a new biological material derived from porcine vagina (acellular vaginal matrix, AVM) to reconstruct the vagina in Bama miniature pigs. The histological characteristics and efficacy of acellularization of AVM were evaluated, and AVM was subsequently transplanted into Bama miniature pigs to reconstruct the vaginas. Results: Macroscopic analysis showed that the neovaginas functioned well in all Bama miniature pigs with AVM implants. Histological analysis and electrophysiological evidence indicated that morphological and functional recovery was restored in normal vaginal tissues. Scanning electron microscopy showed that the neovaginas had mucosal folds characteristics of normal vagina. No significant differences were observed in the expression of CK14, HSP47, and α-actin between the neovaginas and normal vaginal tissues. However, the expression of estrogen receptor (ER) was significantly lower in the neovaginas than in normal vaginal tissues. In addition, AVM promoted the expression of β-catenin, c-Myc, and cyclin D1. These results suggest that AVM might promotes vaginal regeneration by activating the β-catenin/c-Myc/cyclin D1 pathway. Conclusion: This study reveals that porcine-derived AVM has potential application for vaginal regeneration.