EXPERIMENTAL RESEARCH OF VORTEX STRUCTURE OF THE FLOW AROUND A HORIZONTAL CIRCULAR CYLINDER AT VARIOUS GAP-RATIOS IN THE CROSS-FLOW OF SHALLOW WATER

QI E-RONG,LI GUO-YA,LI WEI,WU JIAN,ZHANG XIN 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Experimental study of vibration characteristics of FRP cables based on Long-Gauge strain

Qi Xia,JiaJia Wu,XueWu Zhu,Jian Zhang 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.6

Steel cables as the most important components are widely used in the certain types of structures such as cablesupported bridges, but the long-span structures may result in an increase in fatigue under high stress and corrosion of steel cables. The traditional steel cable is becoming a more evident hindrance. Fiber Reinforced Polymer (FRP) cables with lightweight, high-strength are widely used in civil engineering, but there is little research in vibrational characteristics of FRP cables, especially on the damping characteristic. This article studied the two methods to evaluate dynamical damping characteristic of basalt FRP(BFRP) and glass FRP(GFRP) cables. First, the vibration tests of the B/G FRP cables with different diameter and different cable force were executed. Second, the cables forces were calculated using dynamic strain, static strain and dynamic acceleration respectively, which were further compared with the measured force. Third, experimental modal damping of each cables was calculated by the half power point method, and was compared with the calculation by Rayleigh damping theory and energy dissipation damping theory. The results indicate that (1) The experimental damping of FRP cables decreases with the increase of cable force, and the trend of experimental damping changes is roughly similar with the theoretical damping. (2) The distribution of modal damping calculated by Rayleigh damping theory is closer to the experimental results, and the damping performance of GFRP cables is better than BFRP cables.

Evaluate Dry Deposition Velocity of the Nitrogen Oxides Using Noah-MP Physics Ensemble Simulations for the Dinghushan Forest, Southern China

Qi Zhang,Ming Chang,Shengzhen Zhou,Weihua Chen,Xuemei Wang,Wenhui Liao,Jianing Dai,ZhiYong Wu 한국기상학회 2017 Asia-Pacific Journal of Atmospheric Sciences Vol.53 No.4

There has been a rapid growth of reactive nitrogen (Nr) deposition over the world in the past decades. The Pearl River Delta region is one of the areas with high loading of nitrogen deposition. But there are still large uncertainties in the study of dry deposition because of its complex processes of physical chemistry and vegetation physiology. At present, the forest canopy parameterization scheme used in WRF-Chem model is a single-layer “big leaf” model, and the simulation of radiation transmission and energy balance in forest canopy is not detailed and accurate. Noah-MP land surface model (Noah-MP) is based on the Noah land surface model (Noah LSM) and has multiple parametric options to simulate the energy, momentum, and material interactions of the vegetation-soil-atmosphere system. Therefore, to investigate the improvement of the simulation results of WRF-Chem on the nitrogen deposition in forest area after coupled with Noah-MP model and to reduce the influence of meteorological simulation biases on the dry deposition velocity simulation, a dry deposition single-point model coupled by Noah- MP and the WRF-Chem dry deposition module (WDDM) was used to simulate the deposition velocity (Vd). The model was driven by the micro-meteorological observation of the Dinghushan Forest Ecosystem Location Station. And a series of numerical experiments were carried out to identify the key processes influencing the calculation of dry deposition velocity, and the effects of various surface physical and plant physiological processes on dry deposition were discussed. The model captured the observed Vd well, but still underestimated the Vd. The self-defect of Wesely scheme applied by WDDM, and the inaccuracy of built-in parameters in WDDM and input data for Noah-MP (e.g. LAI) were the key factors that cause the underestimation of Vd. Therefore, future work is needed to improve model mechanisms and parameterization.

Optimal layout of long-gauge sensors for deformation distribution identification

Jian Zhang,Qingqing Zhang,Qi Xia,Zhishen Wu 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.18 No.3

Structural deflection can be identified from measured strains from long gague sensors, but the sensor layout scheme greatly influences on the accuracy of identified resutls. To determine the optimal sensor layout scheme for accurate deflection identification of the tied arch bridge, the method of optimal layout of long-gauge fiber optic sensors is studied, in which the characteristic curve is first developed by using the bending macro-strain curve under multiple target load conditions, then optimal sensor layout scheme with different number of sensors are determined. A tied arch bridge is studied as an example to verify the effectiveness and robustness of the proposed method for static and dynamic deflection identification.

Construction of Recombinant Pichia pastoris Carrying a Constitutive AvBD9 Gene and Analysis of Its Activity

( Jian Tu ),( Kezong Qi ),( Ting Xue ),( Haiting Wei ),( Yongzheng Zhang ),( Yanli Wu ),( Xiuhong Zhou ),( Xiaolong Lv ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.12

Avian beta-defensin 9 (AvBD9) is a small cationic peptide consisting of 41 amino acids that plays a crucial rule in innate immunity and acquired immunity in chickens. Owing to its wide antibacterial spectrum, lack of a residue, and failure to induce bacterial drug resistance, AvBD9 is expected to become a substitute for conventional antibiotics in the livestock and poultry industries. Using the preferred codon of Pichia pastoris, the mature AvBD9 peptide was designed and synthesized, based on the sequence from GenBank. The P. pastoris constitutive expression vector pGHKα was used to construct a pGHKα-AvBD9 recombinant plasmid. Restriction enzyme digestion was performed using SacI and BglII to remove the ampicillin resistance gene, and the plasmid was electrotransformed into P. pastoris GS115. High-expression strains with G418 resistance were screened, and the culture supernatant was analyzed by Tricine-SDS-PAGE and western blot assay to identify target bands of about 6 kDa. A concentrate of the supernatant containing AvBD9 was used for determination of antimicrobial activity. The supernatant concentrate was effective against Escherichia coli, Salmonella paratyphi, Salmonella pullorum, Pseudomonas aeruginosa, Enterococcus faecalis, and Enterobacter cloacae. The fermentation product of P. pastoris carrying the recombinant AvBD9 plasmid was adjusted to 1.0 × 108 CFU/ml and added to the drinking water of white feather broilers at different concentrations. The daily average weight gain and immune organ indices in broilers older than 7 days were significantly improved by the AvBD9 treatment.

Dynamic experimental study on single and double beam-column joints in steel traditional-style buildings

Jian-yang Xue,Liangjie Qi,Kun Yang,Zhanjing Wu 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.5

In order to study the failure mode and seismic behavior of the interior-joint in steel traditional-style buildings, a single beam-column joint and a double beam-column joint were produced according to the relevant building criterion of ancient architectural buildings and the engineering instances, and the dynamic horizontal loading test was conducted by controlling the displacement of the column top and the peak acceleration of the actuator. The failure process of the specimens was observed, the bearing capacity, ductility, energy dissipation capacity, strength and stiffness degradation of the specimens were analyzed by the load-displacement hysteresis curve and backbone curve. The results show that the beam end plastic hinge area deformed obviously during the loading process, and tearing fracture of the base metal at top and bottom flange of beam occurred. The hysteresis curves of the specimens are both spindle-shaped and plump. The ultimate loads of the single beam-column joint and double beam-column joint are 48.65 kN and 70.60 kN respectively, and the equivalent viscous damping coefficients are more than 0.2 when destroyed, which shows the two specimens have great energy dissipation capacity. In addition, the stiffness, bearing capacity and energy dissipation capacity of the double beam-column joint are significantly better than that of the single beam-column joint. The ductility coefficients of the single beam-column joint and double beam-column joint are 1.81 and 1.92, respectively. The cracks grow fast when subjected to dynamic loading, and the strength and stiffness degradation is also degenerated quickly.

Study on Patent Forewarning Evaluation Index System of High & New Technology Enterprises

Wu Jian-long,Wang Hong-qi,Tao Wei-wei 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

In the era of knowledge economy, patent technology is the key factor for high and new technology enterprises to participate in the global competition and maintain continually competitive advantage, meanwhile, monopoly rent and innovation rent of patent technology is also suffered from the challenge of profession technology change and patent strategy of competitors. Thus, regarding patent risk factors of hight and new technology enterprises, the paper constructs patent forewarning evaluation index which involves four aspects of patent protection, quantity, quality and industrialization level, and proposes using tactics of the evaluation index during the enterprises patent forewarning, so as to provide method support for high and new technology enterprises to operate their patent forewarning mechanism effectively.

VISUALIZATION ON VORTEX OF CROSS FLOW PAST A CIRCULAR CYLINDER NEAR A WALL BY PIV

JIAN WU,HUANG SHE-HUA,QI E-RONG,WEI LI 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Fault Detection for Interconnected Systems Subject to Packet Dropouts via Switching Scheme

Jian Li,Jingjing Wang,Qingyu Su,Chun-Yu Wu,Xiao-Qi Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.12

The design of fault detection filter for interconnected systems with packet dropouts occurring in measurement channels is proposed in this paper. Taking into account arbitrary disconnected interconnection among subsystems, switching scheme is introduced to simplify the analysis of the problem. By modeling these situations as independent subsystems, the novel systems based on arbitrary switched systems are remodeled. The design of the filter makes the augmented system exponentially stable and satisfies the disturbance attenuation performance. A feasible linear matrix inequality for the existence of filter is derived by switched Lyapunov method based on stochastic function. Finally, two examples are shown to illustrate the method and its effectiveness.

Dual-pumped nondegenerate four-wave mixing in semiconductor laser with a built-in external cavity

Wu, Jian-Wei,Qiu, Qi,Hyub Won, Yong IOP 2017 Journal of optics Vol.19 No.4

<P>In this paper, a semiconductor laser system consisting of a conventional multimode Fabry–Pérot laser diode with a built-in external cavity is presented and demonstrated. More than two resonance modes, whose peak levels are significantly higher than other residual modes, are simultaneously supported and output by adjusting the bias current and operating temperature of the active region. Based on this device, dual-pumped nondegenerate four-wave mixing—in which two pump waves and a single signal wave are simultaneously fed into the laser, and the injection power and wavelength of the injected pump and signal waves are changed—is observed and discussed thoroughly. The results show that while the wavelengths of pump wave A and signal wave S are kept constant, the other pump wave B jumps from about 1535 nm to 1578 nm, generating conversion signals with changed wavelengths. The achieved conversion bandwidth between the primary signal and the converted signal waves is broadly tunable in the range of several terahertz frequencies. Both the conversion efficiency and optical signal-to-noise ratio of the newly generated conversion signals are adopted to evaluate the performance of the proposed four-wave mixing process, and are strongly dependent on the wavelength and power of the injected waves. Here, the attained maximum conversion efficiency and optical signal-to-noise ratio are close to −22 dB and 15 dB, respectively.</P>