DNA barcoding identification and genetic diversity of bamboo shoot wireworms (Coleoptera: Elateridae) in South China

Shouke Zhang,Yaning Liu,Jinping Shu,Wei Zhang,Yabo Zhang,Haojie Wang 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

Wireworms are recognized as economically important oligophagous pests of Phyllostachys bamboo shoot, which have caused a huge economic loss in South China. Studies of bamboo shoot wireworm control and management were seriously hampered by the lack of reliable identification of larvae. DNA barcoding has been proved to be an important and useful tool in species identification of morphologically cryptic insects. Accurate knowledge of damage-causing species and the phylogenic structure of elaterids will provide insight into their sustainable and effective management. Here, we use interspecific variation in COI and EF1-a as a robust method of identification and consider the intra- and interspecific genetic variation of bamboo wireworms. This approach has revealed that three Melanotus larvae occurred in Phyllostachys forest. The dominance of one species in different sampling location suggests there maybe underlying difference in habit and host plant preference. These data provide a starting point for determining the distribution of wireworm species feeding on bamboo shoots in South China. The inclusions would further aid identification of wireworm species and relationships between certain wireworm species with specific environments.

Regional Cathodic Protection Design of a Natural Gas Distribution Station

( Hu Yabo ),( Zhang Feng ),( Zhao Jun ) 한국부식방식학회(구 한국부식학회) 2017 Corrosion Science and Technology Vol.16 No.5

Regional cathodic protection has significant impact on pipeline integrity management. After risk analyses of a newly built gas distribution station constructed in an area with large dwelling density, risk score was high because of potential threat caused by galvanic corrosion. Except reinforced steel in concrete, there are four kinds of metal buried under earth: carbon steel, galvanized flat steel, zinc rod and graphite module. To protect buried pipeline from external corrosion, design and construction of regional cathodic protection was proposed. Current density was measured with potential using potential dynamic test and boundary element method (BEM) was used to calculate current requirement and optimize best anode placement during design. From our calculation on the potential, optimized conditions for this area were that an applied current was 3A and anode was placed at 40 meters deep from the soil surface. It results in potential range between -1.128 V_CSE and -0.863 V_CSE, meeting the -0.85 V_CSE criterion and the -1.2 V_CSE criterion that no potential was more negative than -1.2 V_CSE to cause hydrogen evolution at defects in coating of the pipeline.

Singular periodic solutions of a class of elastodynamics equations

Xuegang Yuan,Yabo Zhang 한국전산응용수학회 2009 Journal of applied mathematics & informatics Vol.27 No.3

A second order nonlinear ordinary differential equation is obtained by solving the initial-boundary value problem of a class of elastodynamics equations, which models the radially symmetric motion of a incompressible hyper-elastic solid sphere under a suddenly applied surface tensile load. Some new conclusions are presented. All existence conditions of nonzero solutions of the ordinary differential equation, which describes cavity formation and motion in the interior of the sphere, are presented. It is proved that the differential equation has singular periodic solutions only when the surface tensile load exceeds a critical value, in this case, a cavity would form in the interior of the sphere and the motion of the cavity with time would present a class of singular periodic oscillations, otherwise, the sphere remains a solid one. To better understand the results obtained in this paper, the modified Varga material is considered simultaneously as an example, and numerical simulations are given. A second order nonlinear ordinary differential equation is obtained by solving the initial-boundary value problem of a class of elastodynamics equations, which models the radially symmetric motion of a incompressible hyper-elastic solid sphere under a suddenly applied surface tensile load. Some new conclusions are presented. All existence conditions of nonzero solutions of the ordinary differential equation, which describes cavity formation and motion in the interior of the sphere, are presented. It is proved that the differential equation has singular periodic solutions only when the surface tensile load exceeds a critical value, in this case, a cavity would form in the interior of the sphere and the motion of the cavity with time would present a class of singular periodic oscillations, otherwise, the sphere remains a solid one. To better understand the results obtained in this paper, the modified Varga material is considered simultaneously as an example, and numerical simulations are given.

Energy Evolution and Transfer Characteristics in Spatial Particle–Spring–Beam Model

Weipeng Hu,Yabo He,Fan Zhang,Qiang Zhou 한국항공우주학회 2024 International Journal of Aeronautical and Space Sc Vol.25 No.2

Reproducing the orbit–attitude–vibration coupling dynamic behaviors of the complex flexible spatial structure provides the basis on the orbit design, the attitude adjustment and the vibration control of the structure. In this paper, the tug–tether–debris system is simplified as a spatial particle–spring–beam physical model, in which, the non-smooth stiffness coefficient of the spring is assumed to describe the tension/loose state switching of the tether. Based on the variational principle, the coupling dynamic equations are deduced for the spatial particle–spring–beam model. To investigate the energy evolution and the energy transfer characteristics of the model, the structure-preserving iteration method is developed focusing on the non-smooth stiffness coefficient of the spring. In the structure-preserving iteration method, the symplectic Runge–Kutta method is employed to solve the ordinary differential equations mainly controlling the plane motion of the system and the multi-symplectic method is employed to solve the transverse vibration of the beam in the model. The structure-preserving characteristics of the iteration method result from the symplectic structure contained in the symplectic Runge–Kutta method and the multi-symplectic structure contained in the multi-symplectic method. In the stages when the spring is in a complete loose or a complete tension state, the total energy of system is a conservative quantity that is preserved by the structure- preserving iteration method in the simulation. In addition, the energy transfer laws of the system in the tension process of the spring are revealed numerically, which gives some guidance on the active flexible space debris removal strategy design directly.

SINGULAR PERIODIC SOLUTIONS OF A CLASS OF ELASTODYNAMICS EQUATIONS

Yuan, Xuegang,Zhang, Yabo The Korean Society for Computational and Applied M 2009 Journal of applied mathematics & informatics Vol.27 No.3

A second order nonlinear ordinary differential equation is obtained by solving the initial-boundary value problem of a class of elas-todynamics equations, which models the radially symmetric motion of a incompressible hyper-elastic solid sphere under a suddenly applied surface tensile load. Some new conclusions are presented. All existence conditions of nonzero solutions of the ordinary differential equation, which describes cavity formation and motion in the interior of the sphere, are presented. It is proved that the differential equation has singular periodic solutions only when the surface tensile load exceeds a critical value, in this case, a cavity would form in the interior of the sphere and the motion of the cavity with time would present a class of singular periodic oscillations, otherwise, the sphere remains a solid one. To better understand the results obtained in this paper, the modified Varga material is considered simultaneously as an example, and numerical simulations are given.

Microfluidic continuous flow synthesis of 1,5-ditosyl-1,5-diazocane- 3,7-dione using response surface methodology

Yang Zou,Tao Zhang,Guannan Wang,Mengwen Zhou,Yabo Xiong,Shaoyun Huang,Houbin Li,Xinghai Liu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.82 No.-

3,3,7,7-tetrakis(difluoroamino) octahydro-1,5-dinitro-1,5-diazocine (HNFX) is a high-density energeticoxidizer with four difluoroamino groups (-NF2). In this study, 1,5-ditosyl-1,5-diazocane-3,7-dione, as animportant intermediate for synthesis of HNFX, was successfully synthesized using Swern oxidation in atraditional batch reactor and a continuousflow microreactor, respectively. 1,5-dotosyl-1,5-diazocane-3,7-dione was characterized by HPLC, FTIR, 1H NMR, 13C NMR, Mass spectrometry, and X-ray crystaldiffraction. Compared with the traditional batch reactor, the microreactor showed several advantages,including less reaction time, milder reaction temperature, higher yield and selectivity for 1,5-ditosyl-1,5-diazocane-3,7-dione. Moreover, the microreactor could ensure the safer and large-scale industrialproduction of 1,5-ditosyl-1,5-diazocane-3,7-dione. However, some solids produced in Swern oxidationwhich might block the channels (diameter of 0.3 mm) in the microreactor. To overcome the challenges,the experimental device was modified to suit for Swern oxidation, contributing to wider application ofthe microreactor. Besides, response surface methodology (RSM) was introduced and an appropriatemathematical model was built to optimize experimental conditions. The optimum experimentalparameters were recommended as 7.8 C for the reaction temperature, 7.7 mL/min for theflow rate, and6% for the concentration of oxalyl chloride. The actual yield of 1,5-ditosyl-1,5-diazocane-3,7-dione was89.7%, which was in great agreement with the highest predicted yield (90.1%).

Synthesis and Optical Characteristics of PAM/HgS Nanocomposites

Qin, Dezhi,Yang, Guangrui,Zhang, Li,Du, Xian,Wang, Yabo Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

Polyacrylamide (PAM) -HgS nanocomposites were successfully prepared in polyacrylamide (PAM) matrix. From TEM and XRD characterizations, the synthesized HgS nanocrystals were chain-like spherical in shape with a diameter of about 40-60 nm and high crystalline quality. The quantum-confined effect of HgS nanocrystals was confirmed by UV-vis diffuse reflection spectra. The optical properties of products were investigated by using photoluminescence (PL) spectra, which showed that HgS nanocrystals exhibited good optical properties with maximum emission peak at about 640 and 650 nm at different reaction temperatures. The interaction of HgS nanocrystals with PAM was studied through FT-IR spectroscopy and TG analysis, which suggested that $Hg^{2+}$ could interact with functional groups of PAM. The experimental results indicated that PAM not only induced nucleation, but also inhibited further growth of HgS crystals and play an important role in the formation of PAM/HgS nanocomposites. In addition, the possible mechanism of HgS nanoparticles growth in PAM solution was also discussed.

Synthesis and Optical Characteristics of PAM/HgS Nanocomposites

Dezhi Qin,Guangrui Yang,Li Zhang,Xian Du,Yabo Wang 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

Polyacrylamide (PAM) -HgS nanocomposites were successfully prepared in polyacrylamide (PAM) matrix. From TEM and XRD characterizations, the synthesized HgS nanocrystals were chain-like spherical in shape with a diameter of about 40-60 nm and high crystalline quality. The quantum-confined effect of HgS nanocrystals was confirmed by UV-vis diffuse reflection spectra. The optical properties of products were investigated by using photoluminescence (PL) spectra, which showed that HgS nanocrystals exhibited good optical properties with maximum emission peak at about 640 and 650 nm at different reaction temperatures. The interaction of HgS nanocrystals with PAM was studied through FT-IR spectroscopy and TG analysis, which suggested that Hg2+ could interact with functional groups of PAM. The experimental results indicated that PAM not only induced nucleation, but also inhibited further growth of HgS crystals and play an important role in the formation of PAM/HgS nanocomposites. In addition, the possible mechanism of HgS nanoparticles growth in PAM solution was also discussed.