SNPs in the coding region of bovine MGAT2 gene are associated with body weight and weight gain

Lian Qu,Mingjuan Yang,Jinlong Zhu,Junxia Liu,Mijie Li,Liangzhi Zhang,Xianyong Lan,Chuzhao Lei,Chunlei Zhang,Hong Chen 한국유전학회 2011 Genes & Genomics Vol.33 No.3

Monoacylglycerol acyltransferase 2 (MGAT2), as a candidate gene for quantitative traits, relates to dietary fat uptake, lipids synthesis and storage, which plays a major role in the absorption of dietary fat by catalyzing the resynthesis of triacylglycerol in enterocytes. In this study, based on DNA pool sequencing and PCR‐RFLP methods, polymorphisms of the MGAT2 gene were detected in 1145 Chinese indigenous cattle. The results revealed two novel mutations located on exon 1and exon 5 (NM_001099136.1:m.84G>T and 756A>G). Hence, we described the HaeIII forced PCR–RFLP method in exon1 and a MluI PCR–RFLP method in exon5 to detect them. In addition, the associations of these polymorphisms with growth traits were evaluated in Nanyang cattle. The results showed that only HaeIII locus was associated with body weight and average daily gain aged 6 months, and individuals with genotype TT showed significantly higher body weight and average daily gain than those with genotype GG.

Comparison between wind load by wind tunnel test and in-site measurement of long-span spatial structure

Liu, Hui,Qu, Wei-Lian,Li, Qiu-Sheng Techno-Press 2011 Wind and Structures, An International Journal (WAS Vol.14 No.4

The full-scale measurements are compared with the wind tunnel test results for the long-span roof latticed spatial structure of Shenzhen Citizen Center. A direct comparison of model testing results to full-scale measurements is always desirable, not only in validating the experimental data and methods but also in providing better understanding of the physics such as Reynolds numbers and scale effects. Since the quantity and location of full-scale measurements points are different from those of the wind tunnel tests taps, the weighted proper orthogonal decomposition technique is applied to the wind pressure data obtained from the wind tunnel tests to generate a time history of wind load vector, then loads acted on all the internal nodes are obtained by interpolation technique. The nodal mean wind pressure coefficients, root-mean-square of wind pressure coefficients and wind pressure power spectrum are also calculated. The time and frequency domain characteristics of full-scale measurements wind load are analyzed based on filtered data-acquisitions. In the analysis, special attention is paid to the distributions of the mean wind pressure coefficients of center part of Shenzhen Citizen Center long-span roof spatial latticed structure. Furthermore, a brief discussion about difference between the wind pressure power spectrum from the wind tunnel experiments and that from the full-scale in-site measurements is compared. The result is important fundament of wind-induced dynamic response of long-span spatial latticed structures.

Moving Train Loads Identification on a Continuous Steel Truss Girder by Using Dynamic Displacement Influence Line Method

Yi Wang,Wei-Lian Qu 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.2

This paper presents a dynamic displacement influence line method for moving load identification on bridge. The finite element model of Poyang Lake continuous truss bridge-train systems is established and the dispersed modal shapes are acquired by modal analysis. Multi-axle moving train loads are identified with simulated annealing genetic algorithm by minimizing the errors between the measured displacements and the reconstructed displacements from the identified moving loads. In the identification process, the dynamic displacement influence line technique is used to calculate the time history displacement responses of the bridge to avoid solving equations of motion of the bridge repetitively. Several important parameters of the bridge-train system are discussed to investigate their effects on the proposed method. The results demonstrate that the proposed method is an accurate and efficient method for moving train load identification on complex bridges.

Comparison between wind load by wind tunnel test and in-site measurement of long-span spatial structure

Hui Liu,Wei-lian Qu,Qiu-sheng Li 한국풍공학회 2011 Wind and Structures, An International Journal (WAS Vol.14 No.4

The full-scale measurements are compared with the wind tunnel test results for the long-span roof latticed spatial structure of Shenzhen Citizen Center. A direct comparison of model testing results to full-scale measurements is always desirable, not only in validating the experimental data and methods but also in providing better understanding of the physics such as Reynolds numbers and scale effects. Since the quantity and location of full-scale measurements points are different from those of the wind tunnel tests taps, the weighted proper orthogonal decomposition technique is applied to the wind pressure data obtained from the wind tunnel tests to generate a time history of wind load vector, then loads acted on all the internal nodes are obtained by interpolation technique. The nodal mean wind pressure coefficients,root-mean-square of wind pressure coefficients and wind pressure power spectrum are also calculated. The time and frequency domain characteristics of full-scale measurements wind load are analyzed based on filtered data-acquisitions. In the analysis, special attention is paid to the distributions of the mean wind pressure coefficients of center part of Shenzhen Citizen Center long-span roof spatial latticed structure. Furthermore, a brief discussion about difference between the wind pressure power spectrum from the wind tunnel experiments and that from the full-scale in-site measurements is compared. The result is important fundament of wind-induced dynamic response of long-span spatial latticed structures.

CADMIUM TELLURIDE NANOCRYSTALS: SYNTHESIS, GROWTH MODE AND EFFECT OF REACTION TEMPERATURE ON CRYSTAL STRUCTURES

XIAO-YING QI,KAN-YI PU,QU-LI FAN,DUO-FENG TANG,GUI-AN WEN,FREDDY Y. C. BOEY,LIAN-HUI WANG,WEI HUANG,HUA ZHANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.2

A series of cadmium telluride (CdTe) nanocrystals were synthesized by a modified organometallic synthesis method at various reaction temperatures ranging from 130 to 250°C. In this method, octadecylamine (ODA) was introduced as an additional coordinating component to the mixture of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP). CdO was used as a precursor. The prepared CdTe nanocrystals were studied by the absorption and emission spectra as well as the powder X-ray diffraction (XRD) patterns. The result shows that besides the traditional continuous-growth mode observed frequently at relatively high reaction temperature, a discontinuous-growth mode was confirmed at the initial growth stage of CdTe nanocrystals, arising from the change of the absorption spectra of CdTe nanocrystals with the reaction time at relatively low reaction temperature. The structures of CdTe nanocrystals, e.g., the cubic zinc blende structure at 160°C and the hexagonalwurtzite structure at 250°C, were characterized by XRD.

Bolt Loosening Localization at Flange Joints Using Wind-Induced Response for High-Rise Tower

Baifeng Ji,Qian Xiong,Panpan Xing,Penghui Qiu,Wei-lian Qu 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.5

Under long term wind load, the bolt looseness occurring at the joints of tower legs will reduce the wind-resistant capability, increasing the wind-induced displacement responses and aff ecting the serviceability of the high-rise steel tower. In order to detect the bolt looseness locations of the fl ange assembling joints of leg members in high-rise steel tubular tower structures, a new bolt loosening localization at fl ange joints method using wind-induced response for high-rise tower was presented in this paper. Wind-induced vertical strain response root variance of fl ange assembling joint on the tower vertical bar is defi ned as the identifi cation parameter of the bolt looseness damage. Then, the normalized wind-induced vertical strain response root variance is defi ned as the damage index of bolt loose-ness damage, thereby eliminating the impact of wind loads of diff erent magnitudes on damage identifi cation. When the damage index exceeds the threshold, it can be considered that the bolt looseness damage occurs in fl ange assembling joint, thereby to realize the damage identifi cation. The results both numerical analyses of a practical transmission tower and scaled model wind tunnel experiment of a steel tubular tower show that the proposed method is effi cient and noise immunity on the bolt looseness location detection for high-rise tower.

Multiaxial Fatigue Life Prediction Based on High-Cycle Uniaxial Fatigue Test of Steel Pipe Weldments with Welding Defects

Hui Liu,Xiu-wen Lv,Shi-chao Chen,Qiang Zhou,Piao Zhou,Wei-lian Qu 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.1

Welding defects are unavoidable for welded structures, which can lead to fatigue damage even under the random wind load with small amplitude. It is therefore necessary to explore the effect of welding defect on the fatigue properties of welded steel pipes. Three groups of welded steel pipe specimens were designed according to welding defect conditions, i.e. specimens without welding defect (Group I), specimens with incomplete fusion (Group II), and specimens with welding porosity (Group III). Uniaxial tension–compression and torsion high-cycle fatigue tests were carried out. S–N curves of uniaxial tension–compression and torsion tests were obtained by cyclic loading with equal stress amplitude. The test results show that the high-cycle fatigue strength of weldments is obviously lower than that of base metal with the same strength under uniaxial tension–compression and torsion loading. In addition, the welding defects result in a decrease in fatigue strength, while the decrease extent by welding porosity is greater than that by incomplete fusion. Finally, because of the inherent multiaxial loading characteristics of welded structures, the high-cycle multiaxial fatigue life of steel pipe weldments was also predicted by using the modified Wöhler curve method based on the uniaxial fatigue test results. It can be found that when the stress amplitude is constant, the fatigue life of welded steel pipe decreases and the modified Wöhler curves move downward more quickly with the increase of damage parameter defined as the ratio of normal stress amplitude to shear stress amplitude on the critical plane, which means that normal stress amplitude will accelerate the cracks growth and result in faster failure of the weld materials.