Synthesis of molybdenum diselenide nanosheets and its ethanol-sensing mechanism

Zhang, Shaolin,Zhang, Weibin,Nguyen, Thuy Hang,Jian, Jiawen,Yang, Woochul Elsevier 2019 Materials chemistry and physics Vol.222 No.-

<P><B>Abstract</B></P> <P>Molybdenum diselenide (MoSe<SUB>2</SUB>) nanosheets thin film gas sensor was firstly fabricated and its sensing potential to ppm-level ethanol vapor at low operating temperature was investigated. Ultrathin MoSe<SUB>2</SUB> nanosheets were prepared in large scale through a facile liquid-phase exfoliation method using low-boiling-temperature solvent. The exfoliated MoSe<SUB>2</SUB> nanosheets exhibited high purity and crystallinity with few atomic layer thickness. Systematical gas sensing tests demonstrated that MoSe<SUB>2</SUB> nanosheets based thin film could be utilized as ethanol gas sensor with linear response, quick recovery, and good repeatability at 90 °C. The sensing mechanism of MoSe<SUB>2</SUB> toward ethanol was investigated based on first principle calculation. The adsorption behavior of ethanol molecules on MoSe<SUB>2</SUB> surface was revealed in light of adsorption orientation, adsorption energy, charge transfer, projected electronic density of state, and molecular orbital. The calculation well matched with experimental results. It is found the quick and completed recovery of MoSe<SUB>2</SUB> nanosheets sensor was benefited by the appropriate physical interaction between ethanol and MoSe<SUB>2</SUB> surface. This finding offers a competitive option instead of conventional graphene sensor for ethanol gas detection at low temperature.</P>

Microstructure and Compression Strength of W/HfC Composites Synthesized by Plasma Activated Sintering

Jian Zhang,Shuai Ma,Jiawen Zhu,Kejia Kang,Guoqiang Luo,Chuandong Wu,Qiang Shen,Lianmeng Zhang 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

In this work, W/HfC composite materials were synthesized using plasma activated sintering. The influence of the sinteringtemperature and HfC weight fraction on the relative density, microstructure and compression strength were investigated. The results demonstrated that the sintering temperature and the HfC content significantly affected the microstructure of W/HfC composites. Moreover, the grain size of the W/HC composites decreased and the mechanical properties were improvedremarkably due to the addition of HfC. The majority of HfC particles reacted with oxygen impurities to generate HfO2,whichpurified the grain boundaries and refined the grain size of the W matrix. The optimum content of HfC is 2 wt%, at which ahigh compressive strength of 1.98 GPa and a high strain of 34.7% were obtained.

Adaptive Fault-tolerant Control of Alien Species Invasion Based on Sliding Mode

Jiawen Li,Yi Zhang,Yingying Nie,Song Yang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

This paper studies the adaptive fault-tolerant control problem for biological systems with the invasion of alien species. Firstly, to overcome the difficulty of dealing with nonlinear terms in the system, the T-S fuzzy method is applied to obtain the T-S fuzzy biological systems. Then, an augmented matrix is developed for the T-S fuzzy system, and a sliding mode observer is constructed to estimate the state vector, sensor faults, sensor failure and external disturbances. In addition, an observer-based adaptive sliding-mode control law is designed to ensure the stability of the closed-loop biological system. Finally, a simulation example is presented to illustrate the effectiveness of the proposed method.

Analysis of the Transcriptome of Polygonatum odoratum (Mill.) Druce Uncovers Putative Genes Involved in Isofavonoid Biosynthesis

Shengxiang Zhang,Yuanyuan Shi,Chunmiao Shan,Liqiang Zhao,Kelong Ma,Luqi Huang,Jiawen Wu 한국식물학회 2020 Journal of Plant Biology Vol.63 No.3

Polygonatum odoratum (Mill.) Druce (P. odoratum) is a traditional Chinese herb. The isofavonoids of P. odoratum are important medicinal bioactive compounds for the treatment of hypoimmunity, rheumatic heart disease, cardiovascular diseases, and diabetes. This study used RNA sequencing to identify potential genes regulating isofavonoid biosynthesis in P. odoratum. To do this, we generated an overview of metabolic and secondary metabolic pathways, using MAPMAN, and identifed 96 genes encoding seven key enzymes involved in isofavonoid biosynthesis through their KEGG annotation. Alignment of phenylalanine ammonia-lyase or chalcone synthase amino acid sequences revealed well-conserved sequences, spatial structures, and active sites. We also verifed the expression of key genes encoding phenylalanine ammonia-lyase and chalcone synthase by quantitative real-time PCR (qRT-PCR). This analysis of the isofavonoid biosynthesis pathway and its crucial enzymes in P. odoratum lays the foundation for uncovering the regulatory mechanism of isofavonoid biosynthesis.

Modeling-based distribution pattern of herbicide resistance in Beckmanniasyzigachnein the middle and lower reaches of the Yangtze River basin of China

Zheng Zhang,Jiawen Zhuang,Sheng Qiang 한국잡초학회 2017 한국잡초학회 별책(학술대회 초록집) Vol.37 No.1

Efficient Query Processing Platform for Uncertain Big Data

Zhenhua Huang,Jiawen Zhang,Qiang Fang 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.5

Query processing technology has recently received a lot of attention in the business intelligence and information service communities. However, the existing approaches can not efficiently optimize the query performance in the uncertain big data environment. In this paper, we propose QPPUBG, a novel and efficient query processing platform for uncertain big data. QPPUBG mainly includes four modules: (i) query equivalence reconstructing for uncertain big data; (ii) multiple query optimization over probability relation components; (iii) query execution plan constructing over probability relation components, and (iv) physical implementation solution of query for uncertain big data. Specially, QPPUBG can support the possible world instance semantics and efficiently handle arbitrary decision spaces. Moreover, QPPUBG can seamlessly integrate the above four modules into the modern parallel computation frameworks. We present the extensive experiments that demonstrate QPPUBG is both efficient and effective.

Enhanced Acetoin Production by Serratia marcescens H32 Using Statistical Optimization and a Two-stage Agitation Speed Control Strategy

Jianan Sun,Liaoyuan Zhang,Ben Rao,Yunbin Han,Ju Chu,Jiawen Zhu,Yaling Shen,Dong-Zhi Wei 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

Enhanced acetoin production was carried out by Serratia marcescens H32. First, medium compositions were optimized statistically for shake flask fermentations to produce acetoin. Sucrose and corn steep liquor powder (CSLP) were identified as the most significant factors by Plackett–Burman design. The path of steepest ascent and response surface methodology were then employed to determine the optimal concentrations of the two factors. Acetoin yield was up to 41.5 g/L in flask fermentations using the optimized medium. Furthermore, the optimal medium was used to conduct fermentation experiments in a 3.7-L bioreactor. The influences of different agitation speeds on acetoin production were investigated. Based on a process analysis, a two-stage agitation speed control strategy was proposed, in which the agitation speed was controlled at 700 rpm during the first 8 h and then switched to 600 rpm. A relatively high acetoin concentration (44.9 g/L)and high acetoin productivity (1.73 g/L/h) were achieved by applying this strategy. Fed-batch fermentation based on the two-stage agitation speed control strategy was performed,and a maximum acetoin concentration of 60.5 g/L with productivity of 1.44 g/L/h was achieved. Enhanced acetoin production was carried out by Serratia marcescens H32. First, medium compositions were optimized statistically for shake flask fermentations to produce acetoin. Sucrose and corn steep liquor powder (CSLP) were identified as the most significant factors by Plackett–Burman design. The path of steepest ascent and response surface methodology were then employed to determine the optimal concentrations of the two factors. Acetoin yield was up to 41.5 g/L in flask fermentations using the optimized medium. Furthermore, the optimal medium was used to conduct fermentation experiments in a 3.7-L bioreactor. The influences of different agitation speeds on acetoin production were investigated. Based on a process analysis, a two-stage agitation speed control strategy was proposed, in which the agitation speed was controlled at 700 rpm during the first 8 h and then switched to 600 rpm. A relatively high acetoin concentration (44.9 g/L)and high acetoin productivity (1.73 g/L/h) were achieved by applying this strategy. Fed-batch fermentation based on the two-stage agitation speed control strategy was performed,and a maximum acetoin concentration of 60.5 g/L with productivity of 1.44 g/L/h was achieved.

Obstacles modeling method in cluttered environments using satellite images and its application to path planning for USV

Binghua Shi,Huajun Zhang,Jiawen Liu,Lili Wan 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

The obstacles modeling is a fundamental and significant issue for path planning and automatic navigation of Unmanned Surface Vehicle (USV). In this study, we propose a novel obstacles modeling method based on high resolution satellite images. It involves two main steps: extraction of obstacle features and construction of convex hulls. To extract the obstacle features, a series of operations such as sea-land segmentation, obstacles details enhancement, and morphological transformations are applied. Furthermore, an efficient algorithm is proposed to mask the obstacles into convex hulls, which mainly includes the cluster analysis of obstacles area and the determination rules of edge points. Experimental results demonstrate that the models achieved by the proposed method and the manual have high similarity. As an application, the model is used to find the optimal path for USV. The study shows that the obstacles modeling method is feasible, and it can be applied to USV path planning.

Obstacles modeling method in cluttered environments using satellite images and its application to path planning for USV

Shi, Binghua,Su, Yixin,Zhang, Huajun,Liu, Jiawen,Wan, Lili The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

The obstacles modeling is a fundamental and significant issue for path planning and automatic navigation of Unmanned Surface Vehicle (USV). In this study, we propose a novel obstacles modeling method based on high resolution satellite images. It involves two main steps: extraction of obstacle features and construction of convex hulls. To extract the obstacle features, a series of operations such as sea-land segmentation, obstacles details enhancement, and morphological transformations are applied. Furthermore, an efficient algorithm is proposed to mask the obstacles into convex hulls, which mainly includes the cluster analysis of obstacles area and the determination rules of edge points. Experimental results demonstrate that the models achieved by the proposed method and the manual have high similarity. As an application, the model is used to find the optimal path for USV. The study shows that the obstacles modeling method is feasible, and it can be applied to USV path planning.

Coexistence of Subcutaneous Panniculitis-Like T-Cell Lymphoma and Dermatomyositis in a 12-Year-Old Boy

Ruoqu Wei,Haifei Liu,Zhen Zhang,Fuying Chen,Jiawen Chen,Qianyue Xu,Hong Yu,Jianying Liang,Zhirong Yao 대한피부과학회 2023 Annals of Dermatology Vol.35 No.-

Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is an extremely rare, indolent skin malignancy that can be difficult to distinguish from autoimmune disease-associated panniculitides. Here, we describe a 12-year-old boy who was diagnosed at age 7 years with dermatomyositis with classical manifestations, including poikiloderma, Gottron’s sign, and symmetric muscle weakness. Recently, the boy presented multiple subcutaneous nodules and fever. Histopathological examination and immunohistochemical staining revealed co- existence of SPTL. To our knowledge, this is the first case of dermatomyositis accompanied with SPTL. This case alert clinical physicians of the possibility of SPTL should be considered when a patient with dermatomyositis has new lesions presenting as nodules and unknown fever.