Wavelet-transform-based damping identification of a super-tall building under strong wind loads

An Xu,Jiurong Wu,Ruohong Zhao 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.4

A new method is proposed in this study for estimating the damping ratio of a super tall building under strong wind loads with short-time measured acceleration signals. This method incorporates two main steps. Firstly, the power spectral density of wind-induced acceleration response is obtained by the wavelet transform, then the dynamic characteristics including the natural frequency and damping ratio for the first vibration mode are estimated by a nonlinear regression analysis on the power spectral density. A numerical simulation illustrated that the damping ratios identified by the wavelet spectrum are superior in precision and stability to those values obtained from Welch’s periodogram spectrum. To verify the efficiency of the proposed method, wind-induced acceleration responses of the Guangzhou West Tower (GZWT) measured in the field during Typhoon Usagi, which affected this building on September 22, 2013, were used. The damping ratios identified varied from 0.38% to 0.61% in direction 1 and from 0.22% to 0.59% in direction 2. This information is expected to be of considerable interest and practical use for engineers and researchers involved in the wind-resistant design of super-tall buildings.

RNAi suppression of nuclear receptor genes results in increased susceptibility to sulfoxaflor in brown planthopper, Nilaparvata lugens

Lu Xu,Chun-Qing Zhao,De-Jin Xu,Guang-Chun Xu,Xiao-Long Xu,Zhao-Jun Han,Ya-Nan Zhang,Zhong-Yan Gu 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2

Nuclear receptors (NRs), which belong to a superfamily of ligand-dependent transcription factors, play essential roles in gene regulation to affect numerous physiological pathways. Twenty NR genes were identified in Nilaparvata lugens by using genomic, transcriptomic and GenBank databases, and categorized into NR0-NR6 subfamilies according to standard nomenclature. Among them, three NR geneswere classed into NR0, four into NR1, eight into NR2, one into NR3, one into NR4, two into NR5, and one into NR6, respectively. A phylogenetic tree of NRs from N. lugens and other representative species was constructed, which provided evolutionary insight into genetic distance. In order to investigate the NRs,whichwere induced by sulfoxaflor, time- and tissue-specific expression profiles of NR genes in fourth-instar nymphs were determined following LD50 sulfoxaflor treatment (0.28 ng/insect) and compared with control samples. NlUSP, NlE78, NlTLL, NlHR51, NlHR83, NlPNR and NlFTZ-F1 were highly expressed following 12–48 h of sulfoxaflor treatment. NlHR39 and NlDSF transcripts were detected in the head and the thorax, respectively. High-level and constitutive expression of NlHR3, NlTLL, NlHR83, NlFTZF1 and NlHR4 were found in the abdomen. Feeding of dsRNAs reduced the expression of NlHR3, NlUSP, NlTLL, NlHR83, NlPNR, NlFTZ-F1 and NlHR4 (35.48–49.77%) and caused significant nymph mortality (69.21–81.45%). These NRs, considered as insecticide targets, may play important function in sulfoxaflor detoxification.

A Study on Ritual Resistance of V-Tuber Fans

Zhao-Yi Xu,Won-Ho Choi 한국콘텐츠학회 2022 한국콘텐츠학회 ICCC 논문집 Vol.2022 No.12

8q24 rs4242382 Polymorphism is a Risk Factor for Prostate Cancer among Multi-Ethnic Populations: Evidence from Clinical Detection in China and a Meta-analysis

Zhao, Cheng-Xiao,Liu, Ming,Xu, Yong,Yang, Kuo,Wei, Dong,Shi, Xiao-Hong,Yang, Fan,Zhang, Yao-Guang,Wang, Xin,Liang, Si-Ying,Zhao, Fan,Zhang, Yu-Rong,Wang, Na-Na,Chen, Xin,Sun, Liang,Zhu, Xiao-Quan,Yuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: Evidence supporting an association between the 8q24 rs4242382-A polymorphism and prostate cancer (PCa) risk has been reported in North American and Europe populations, though data from Asian populations remain limited. We therefore investigated this association by clinical detection in China, and meta-analysis in Asian, Caucasian and African-American populations. Materials and Methods: Blood samples and clinical information were collected from ethnically Chinese men from Northern China with histologically-confirmed PCa (n=335) and from age-matched normal controls (n=347). The 8q24 (rs4242382) gene polymorphism was genotyped by polymerase chain reaction-high-resolution melting analysis. We initially analyzed the associations between the risk allele and PCa and clinical covariates. A meta-analysis was then performed using genotyping data from a total of 1,793 PCa cases and 1,864 controls from our study and previously published studies in American and European populations, to determine the association between PCa and risk genotype. Results: The incidence of the risk allele was higher in PCa cases than controls (0.222 vs 0.140, $P=7.3{\times}10^{-5}$), suggesting that the 8q24 rs4242382-A polymorphism was associated with PCa risk in Chinese men. The genotypes in subjects were in accordance with a dominant genetic model (ORadj=2.03, 95%CI: 1.42-2.91, $Padj=1.1{\times}10^{-4}$). Presence of the risk allele rs4242382-A at 8q24 was also associated with clinical covariates including age at diagnosis ${\geq}65$ years, prostate specific antigen >10 ng/ml, Gleason score <8, tumor stage and aggressive PCa, compared with the non-risk genotype ($P=4.6{\times}10^{-5}-3.0{\times}10^{-2}$). Meta-analysis confirmed the association between 8q24 rs4242382-A polymorphism and PCa risk (OR=1.62, 95%CI: 1.39-1.88, $P=1.0{\times}10^{-5}$) across Asian, Caucasian and African American populations. Conclusions: The replicated data suggest that the 8q24 rs4242382-A variation might be associated with increased PCa susceptibility in Asian, Caucasian and African American populations. These results imply that this polymorphism may be a useful risk biomarker for PCa in multi-ethnic populations.

Effect of moisture content on dense-phase conveying of pulverized coal at high pressure

Xu Pan,Chen Xiaoping,Liang Cai,Xu Guiling,Liu Daoyin,Zhao Changsui 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.10

In dense-phase pneumatic conveying, the solid moisture content can significantly influence the conveying process, but there are very few studies in the open literature. In this study, the conveying experiments of two pulverized coals with various moisture contents were carried out at a 4MPa high pressure and dense-phase pneumatic conveying facility. Results show that the whole conveying system can be stably and controllably operated under the condition that moisture content below ~8%. With the increase of moisture content up to ~8%, the mass flow rate of 280 μm pulverized coal increases at first and then decreases, while that of 55 μm pulverized coal decreases continuously. The method of solid friction factor correlation is used to investigate pressure drop of the horizontal pipe, and non-dimensional parameters--Fr number, moisture content M and solid loading ratio μ--are investigated. The pressure drop predictions by this correlation are in good agreement with the experimental data. The solid friction factor correlations indicate that the fine coal is more sensitive to M, and μ plays a more important role for the coarse coal.

Non-isothermal Decomposition Kinetics of a New High-energy Organic Potassium Salt: K(DNDZ)

Xu, Kangzhen,Zhao, Fengqi,Song, Jirong,Ren, Xiaolei,Gao, Hongxu,Xu, Siyu,Hu, Rongzu Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.10

A new high-energy organic potassium salt, 2-(dinitromethylene)-1,3-diazepentane potassium salt K(DNDZ), was synthesized by reacting of 2-(dinitromethylene)-1,3-diazepentane (DNDZ) and potassium hydroxide. The thermal behavior and non-isothermal decomposition kinetics of K(DNDZ) were studied with DSC, TG/DTG methods. The kinetic equation is $\frac{d{\alpha}}{dT}$ = $\frac{10^{13.92}}{\beta}$3(1 - $\alpha$[-ln(1 - $\alpha$)]$^{\frac{2}{3}}$ exp(-1.52 ${\times}\;10^5$ / RT). The critical temperature of thermal explosion of K(DNDZ) is $208.63\;{^{\circ}C}$. The specific heat capacity of K(DNDZ) was determined with a micro-DSC method, and the molar heat capacity is 224.63 J $mol^{-1}\;K^{-1}$ at 298.15 K. Adiabatic time-to-explosion of K(DNDZ) obtained is 157.96 s.

Numerical Simulation of Spray Flow in Injector For the Steamjet Engine

( Xu Sheng Shang ),( Jiang Hong Li ),( Ren Hou Zhao ),( Xu Ze Shang ),( Jie Hong Li ) 한국액체미립화학회 2005 한국액체미립화학회 학술강연회 논문집 Vol.2005 No.-

In this paper, according to the work mechanism of SteamJet, With the certain small scaled turbojet for an influence, along flying trajectory calculating mass of import air and injection water, establishing the spray physics model/ mathematics model. Based on the equation of three-dimension Renault average N-S, air to adopt the limited physical volume method, the liquid adopts to the Lagrangian orbit model, with straight injecting the current method ,Simulate the field of air/ liquid two phase flow field to distribute of inlet to carry on mutually. The results indicate that spray have an effect on flow field configuration. It is concluded that the numerical model and CFD method for modeling spray flow processes in gas/liquid injector will be satisfactory. Similar to the SteamJet the United States puts forward, adopting water injection can satisfy to import the conditional request for pressure and temperature of compressor.

Production of Transgenic Pigs with an Introduced Missense Mutation of the Bone Morphogenetic Protein Receptor Type IB Gene Related to Prolificacy

Zhao, Xueyan,Yang, Qiang,Zhao, Kewei,Jiang, Chao,Ren, Dongren,Xu, Pan,He, Xiaofang,Liao, Rongrong,Jiang, Kai,Ma, Junwu,Xiao, Shijun,Ren, Jun,Xing, Yuyun Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.7

In the last few decades, transgenic animal technology has witnessed an increasingly wide application in animal breeding. Reproductive traits are economically important to the pig industry. It has been shown that the bone morphogenetic protein receptor type IB (BMPR1B) A746G polymorphism is responsible for the fertility in sheep. However, this causal mutation exits exclusively in sheep and goat. In this study, we attempted to create transgenic pigs by introducing this mutation with the aim to improve reproductive traits in pigs. We successfully constructed a vector containing porcine BMPR1B coding sequence (CDS) with the mutant G allele of A746G mutation. In total, we obtained 24 cloned male piglets using handmade cloning (HMC) technique, and 12 individuals survived till maturation. A set of polymerase chain reactions indicated that 11 of 12 matured boars were transgene-positive individuals, and that the transgenic vector was most likely disrupted during cloning. Of 11 positive pigs, one (No. 11) lost a part of the terminator region but had the intact promoter and the CDS regions. cDNA sequencing showed that the introduced allele (746G) was expressed in multiple tissues of transgene-positive offspring of No.11. Western blot analysis revealed that BMPR1B protein expression in multiple tissues of transgene-positive $F_1$ piglets was 0.5 to 2-fold higher than that in the transgene-negative siblings. The No. 11 boar showed normal litter size performance as normal pigs from the same breed. Transgene-positive $F_1$ boars produced by No. 11 had higher semen volume, sperm concentration and total sperm per ejaculate than the negative siblings, although the differences did not reached statistical significance. Transgene-positive $F_1$ sows had similar litter size performance to the negative siblings, and more data are needed to adequately assess the litter size performance. In conclusion, we obtained 24 cloned transgenic pigs with the modified porcine BMPR1B CDS using HMC. cDNA sequencing and western blot indicated that the exogenous BMPR1B CDS was successfully expressed in host pigs. The transgenic pigs showed normal litter size performance. However, no significant differences in litter size were found between transgene-positive and negative sows. Our study provides new insight into producing cloned transgenic livestock related to reproductive traits.

Effects of Reynolds number on the flow field in a low-pressure turbine with incoming wakes

Xu Zhao,Yunfei Wang,Xiaozhong Ma,Yaowen Zhang,Long Yue,Bin Zheng 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.11

In order to further understand the effects of the Reynolds number on the flow field within a low-pressure turbine with incoming wakes, the transition SST turbulence model was employed for numerical simulation under four Reynolds number conditions ranging from 0.6×10 5 to 3.0×10 5 . The numerical results showed that the boundary layer separation at the rear part of the suction surface was prone to occur in the condition of low Reynolds number (Re 2th = 0.6×10 5 ), and the separation bubble was semi-open and semi-closed. The separation bubble impedes the development of the passage vortex and wall vortex towards mid-span region. When the Reynolds number exceeds 1.0×10 5 , boundary layer separation does not occur. The influence of Reynolds number on the total pressure loss coefficient is primarily evident on the suction surface side, and the growth rate of total pressure loss coefficient first increases and then decreases along the streamwise direction. As the Reynolds number increases from 0.6×10 5 to 3.0×10 5 , the peak point location of total pressure loss decreases by approximately 12 %. The influence of Reynolds number on corner vortex and wall vortex is relatively more sensitive compared to that of passage vortex.

Warm

Zhao Chen Xu 한국콘텐츠학회 2018 ICCC International Digital Design Invitation Exhib Vol.2018 No.7