The conceptual design of grid-connected wind turbine based on speed regulating differential mechanism

Xiaoming Rui,Rui Su,Xin Wu,Qidong Yin 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6

In view of problems arising from the grid-connected wind turbine with the frequency converter, we propose a conceptual design ofgrid-connected wind turbine based on speed regulating differential mechanism (SRDM). The SRDM regulates its output speed andtorque self-adaptively referring to wind rotor and makes the synchronous generator (SG) keep a constant speed to output electricity insteady frequency without the normal frequency converter and it has excellent low voltage ride through (LVRT). This paper offers thekinematics and dynamics analysis of the designed wind turbine and builds the SIMULINK model based on FAST (fatigue, aerodynamics,structures and turbulence) software. The simulation of speed, torque and power of wind rotor under average wind speed of 12 m/s andturbulence intensity of 20% can verify the feasibility of the designed wind turbine.

The characteristic of the synonymous codon usage and phylogenetic analysis of hepatitis B virus

Xiaoming Qi,Chaojun Wei,Yonghong Li,Yu Wu,Hui Xu,Rui Guo,Yanjuan Jia,Zhenhao Li,Zhenhong Wei,Wanxia Wang,Jing Jia,Yuanting Li,Anqi Wang,Xiaoling Gao 한국유전학회 2020 Genes & Genomics Vol.42 No.7

Background Hepatitis B virus (HBV) infection is a crucial medical issue worldwide. The dependence of HBV replication on host cell machineries and their co-evolutionary interactions prompt the codon usage pattern of viral genes to translation selection and mutation pressure. Objective The evolutionary characteristics of HBV and the natural selection effects of the human genome on the codon usage characteristics were analyzed to provide a basis for medication development for HBV infection. Methods The codon usage pattern of sequences from different HBV genotypes of our isolates and reference HBV genome sequences downloaded from the National Center for Biotechnology Information (NCBI) database were analyzed by computing the relative synonymous codon usage (RSCU), nucleotide content, codon adaptation index (CAI) and the effective number of codons (ENC). Results The highest ENC values were observed in the C genotypes, followed by the B genotypes. The ENC values indicated a weak codon usage bias (CUB) in HBV genome. The number of codons differentially used between the three genotypes was markedly higher than that of similarly used codons. High CAI values indicated a good adaptability of HBV to its host. The ENC plot indicated the occurrence of mutational pressure in the three genotypes. The mean Ka/Ks ratios in the three genotypes were lower than 1, which indicated a negative selection pressure. The CAI and GC3% plot indicated the existence of CUB in the HBV genome. Conclusions Nucleotide composition, mutation bias, negative selection and mutational pressure are key factors influencing the CUB and phylogenetic diversity in HBV genotypes. The data provided here could be useful for developing drugs for HBV infection.

A Learning-based Power Control Scheme for Edge-based eHealth IoT Systems

( Haoru Su ),( Xiaoming Yuan ),( Yujie Tang ),( Rui Tian ),( Enchang Sun ),( Hairong Yan ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.12

The Internet of Things (IoT) eHealth systems composed by Wireless Body Area Network (WBAN) has emerged recently. Sensor nodes are placed around or in the human body to collect physiological data. WBAN has many different applications, for instance health monitoring. Since the limitation of the size of the battery, besides speed, reliability, and accuracy; design of WBAN protocols should consider the energy efficiency and time delay. To solve these problems, this paper adopt the end-edge-cloud orchestrated network architecture and propose a transmission based on reinforcement algorithm. The priority of sensing data is classified according to certain application. System utility function is modeled according to the channel factors, the energy utility, and successful transmission conditions. The optimization problem is mapped to Q-learning model. Following this online power control protocol, the energy level of both the senor to coordinator, and coordinator to edge server can be modified according to the current channel condition. The network performance is evaluated by simulation. The results show that the proposed power control protocol has higher system energy efficiency, delivery ratio, and throughput.

OBSERVATIONS OF RADIO STARS FROM ASTROLABE OF YUNNAN OBSERVATORY

HU HUI,LI DONGMING,LI XIAOMING,WANG RUI The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

Mechanisms and kinetics of zinc and iron separation enhanced by calcified carbothermal reduction for electric arc furnace dust

Jiayong Qiu,Shui Yu,Jiugang Shao,Kaiqi Zhu,Dianchun Ju,Chunyu Chen,Dexing Qi,Fei Wang,Ni Bai,Rui Mao,Xiaoming Wang 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.4

A high basicity charge prepared with electric arc furnace dust (EAFD), carbonaceous reducing agent and CaO is proposed. The mechanisms of enhancing separation of zinc and iron by calcified carbothermic reduction of the high basicity charge were analyzed by combining thermal analysis kinetics and experiment. The influences of roasting temperature, carbon ratio (nc/no, molar ratio of carbon in graphitic carbon powder to oxygen in EAFD), and CaO dosage on phase transition and dezincification ratio in EAFD were investigated. The results show that the intermediates Ca2Fe2O5 and Fe0.85−xZnxO can be produced from the zinc-iron separation of zinc ferrate during the process of calcified carbothermic reduction of EAFD. Addition of CaO and C results in the following transition pathways: ZnFe2O4+ CaO→Ca2Fe2O5+ZnO→Ca2Fe2O5+Zn(g)→CaO+Fe; Fe0.85−xZnxO+CaO→Ca2Fe2O5+FeO+ZnO→CaO+Fe+Zn(g). In the range of nc/no of 0.4–1.2 and roasting temperature of 1,000–1,100 °C, the addition of CaO can promote reduction and dezincification. Based on the Kissinger-Akahira-Sunose (KAS) and Coats-Redfern methods, the kinetic results show that the calcified carbothermic reduction process can be divided into three stages: initial stage (α=0–0.3), middle stage (α=0.3–0.45), and final stage (α=0.45–1.0). The average activation energy of the initial stage is 305.01 kJ·mol−1, and the reaction mechanism is one-dimensional diffusion. The average activation energy is 315.67 kJ·mol−1 for the middle stage and 288.22 kJ·mol−1 for the final stage. The chemical reaction equation is found to be the most suitable mechanism in the medium and final stages. It is also found that the addition of CaO can reduce the average activation energy by about 32 kJ·mol−1 and shorten the intermediate stage of the reaction.

Impact of fatty liver on long-term outcomes in chronic hepatitis B: a systematic review and matched analysis of individual patient data meta-analysis

Yu Jun Wong,Vy H. Nguyen,Hwai-I Yang,Jie Li,Michael Huan Le,Wan-Jung Wu,Nicole Xinrong Han,Khi Yung Fong,Elizabeth Chen,Connie Wong,Fajuan Rui,Xiaoming Xu,Qi Xue,Xin Yu Hu,Wei Qiang Leow,George Boon-B 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.3

Background/Aims: Chronic hepatitis B (CHB) and fatty liver (FL) often co-exist, but natural history data of this dual condition (CHB-FL) are sparse. Via a systematic review, conventional meta-analysis (MA) and individual patient-level data MA (IPDMA), we compared liver-related outcomes and mortality between CHB-FL and CHB-no FL patients. Methods: We searched 4 databases from inception to December 2021 and pooled study-level estimates using a random- effects model for conventional MA. For IPDMA, we evaluated outcomes after balancing the two study groups with inverse probability treatment weighting (IPTW) on age, sex, cirrhosis, diabetes, ALT, HBeAg, HBV DNA, and antiviral treatment. Results: We screened 2,157 articles and included 19 eligible studies (17,955 patients: 11,908 CHB-no FL; 6,047 CHB-FL) in conventional MA, which found severe heterogeneity (I2=88–95%) and no significant differences in HCC, cirrhosis, mortality, or HBsAg seroclearance incidence (P=0.27–0.93). IPDMA included 13,262 patients: 8,625 CHB-no FL and 4,637 CHB-FL patients who differed in several characteristics. The IPTW cohort included 6,955 CHB-no FL and 3,346 CHB-FL well-matched patients. CHB-FL patients (vs. CHB-no FL) had significantly lower HCC, cirrhosis, mortality and higher HBsAg seroclearance incidence (all P≤0.002), with consistent results in subgroups. CHB-FL diagnosed by liver biopsy had a higher 10-year cumulative HCC incidence than CHB-FL diagnosed with non-invasive methods (63.6% vs. 4.3%, P<0.0001). Conclusions: IPDMA data with well-matched CHB patient groups showed that FL (vs. no FL) was associated with significantly lower HCC, cirrhosis, and mortality risk and higher HBsAg seroclearance probability.