The relative contributions of internal variability and external forcing to Pacific Walker Circulation over the last millennium

Shijie Wang,Wenmin Man,Feng Chen,Meng Zuo 한국기상학회 2023 한국기상학회 학술대회 논문집 Vol.2023 No.4

Evaluation on Drought Resistance of Native Sickle Alfalfa Germplasm Collected from Different Parts of China

Wang Junjie,Yun Jinfeng,Lv Shijie,Wang Hongmei 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08

39 accessions of sickle alfalfa (Medicago falcata L.) collected from different regions of China were evaluated for their tolerance to drought. Differences were observed among accessions in their reactions to drought and 8 good tolerant accessions at populations level and 18 excellent tolerant accessions at individual level were identified based on drought response index (DRI).

FEM Simulation and Test Verification of PD Ultrasonic Signal Propagation in a Power Transformer Model

Zan Wang,Chaofei Gao,Liwei Zheng,Jikun Ren,Wei Wang,Yushuai Zhang,Shijie Han 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1

Ultrasonic signals will be generated when partial discharge occurs in internal insulation faults in large oil immersed power transformers: because the ultrasonic signal has strong anti-interference ability and has no direct electromagnetic contact with the equipment, it is widely used in transformer fault detection and positioning. In this paper, the fi nite element method (FEM) is used to simulate the ultrasonic signal in a 35 kV power transformer. The infl uence of transformer case on ultrasonic signal propagation is considered, and the propagation law of the ultrasonic signal inside the transformer is obtained. Fabry–Pérot (F–P) fi bre acoustic sensors with a centre frequency of 28 kHz were fabricated. A partial discharge detection test was carried out in a 35 kV transformer winding model using the F–P sensors. The test results show that the ultrasonic waveform detected by the F–P sensors are in good agreement with the simulation results, and the propagation of the ultrasonic wave inside the transformer is verifi ed. It lays a foundation for detecting and locating PDs in power transformer by F–P acoustic sensors.

Cyclooxygenase-2 Polymorphisms and Susceptibility to Colorectal Cancer: A Meta-Analysis

Jun Wang,Xufeng Guo,Jixiang Zhang,Jia Song,Mengyao Ji,Shijie Yu,Jing Wang,Zhuo Cao,Weiguo Dong 연세대학교의과대학 2013 Yonsei medical journal Vol.54 No.6

Purpose: Four polymorphisms, -765G>C, -1195G>A, 8473T>C, and Val511Ala, in the cyclooxygenase-2 (COX-2) gene were identified to be associated with colorectal cancer (CRC) risk. However, the results are inconsistent. The objective of this meta-analysis was to evaluate the association between these four polymorphisms and the risk of CRC. Materials and Methods: All eligible case-control studies published up to December 2012 on the association between the four polymorphisms of COX-2 and CRC risk were identified by searching PubMed and Web of Science. The CRC risk associated with the four polymorphisms of the COX-2 gene was estimated for each study by odds ratio (OR) together with its 95% confidence interval (CI), respectively. Results: A total of 15 case-control studies were included. Overall, no evidence has indicated that the -1195A allele, -765C allele, 8473C allele, and 511Ala allele are associated with susceptibility to CRC (-1195G>A: OR=1.11, 95% CI: 0.82-1.51, p=0.78; -765G>C: OR=1.08, 95% CI: 0.96-1.21, p=0.07; 8473T>C: OR=1.03, 95% CI: 0.89-1.18, p=0.91; Val511Ala:OR=0.71, 95% CI: 0.46-1.09, p=0.94). However, stratified analysis with ethnicity indicated that individuals with -765GC or GC/CC genotypes had an increased risk of CRC among Asian populations (GC vs. GG: OR=1.05, 95% CI: 0.87-1.28, p=0.03; GC+CC vs. GG: OR=1.08, 95% CI: 0.96-1.21, p=0.07). Conclusion: This meta-analysis indicated that -765G>C polymorphism was significantly associated with susceptibility to CRC in Asian populations.

Fucoidan from Acaudina molpadioides Protects Pancreatic Islet against Cell Apoptosis via Inhibition of Inflammation in Type 2 Diabetic Mice

Jinhui Wang,Shiwei Hu,Jingfeng Wang,Shijie Li,Wei Jiang 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.1

Inflammation induces pancreatic islet cell apoptosis. Effects of fucoidan from Acaudina molpadioides (Am-FUC) on inhibition of pancreatic islet cell apoptosis and inflammation in type 2 diabetic mice were investigated. Am-FUC repaired pancreatic islet cells, decreased serum C-reactive protein (CRP), macrophage inflammatory protein 1 (MIP-1), interleukin 1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) levels, and increased the IL-10 level. Am-FUC also reduced TNF-α, CRP, MIP-1, IL-1β, and IL-6 mRNA expressions, and increased IL-10 mRNA expression in epididymal adipose tissues. Am-FUC reduced Bid, Bax, cytochrome c, caspase 9, and caspase 3 mRNA expressions, and increased Bcl-2 and Bcl-xL mRNA expressions. Am-FUC down-regulated t-Bid, Bax, cytochrome c, and caspase 9 activities, cleaved caspase 3 proteins, and up-regulated Bcl-2 and Bcl-xL proteins. Thus, an Am-FUCblocked mitochondrial pathway was the suppression mechanism in pancreatic islet cell apoptosis via regulation of inflammatory cytokines providing dietary intervention in type 2 diabetes and inflammation-induced pancreatic islet apoptosis.

A Parameter Selection Method for Multi-Element Resonant Converters with a Resonant Zero Point

Wang, Yifeng,Yang, Liang,Li, Guodong,Tu, Shijie The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

This paper proposes a parameter design method for multi-element resonant converters (MERCs) with a unique resonant zero point (RZP). This method is mainly composed of four steps. These steps include program filtration, loss comparison, 3D figure fine-tuning and priority compromise. It features easy implementation, effectiveness and universal applicability for almost all of the existing RZP-MERCs. Meanwhile, other design methods are always exclusive for a specific topology. In addition, a novel dual-CTL converter is also proposed here. It belongs to the RZP-MERC family and is designed in detail to explain the process of parameter selection. The performance of the proposed method is verified experimentally on a 500W prototype. The obtained results indicate that with the selected parameters, an extensive dc voltage gain is obtained. It also possesses over-current protection and minimal switching loss. The designed converter achieves high efficiencies among wide load ranges, and the peak efficiency reaches 96.9%.

Characteristics analysis of rotor-rolling bearing coupled system with fit looseness fault and its verification

Wang Haifei,Guan Xiaoying,Chen Guo,Gong Junjie,Yu Liang,Yuan Shijie,Zhu Zhida 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

Outer ring of bearing fit looseness fault is a common fault. Scratch often appears in the inner surface of pedestal. The fit looseness fault mechanism is not clear. For rotor-rolling bearing system with fit looseness fault between rotor-bearing outer ring and pedestal, a rotor coupling dynamic model that the interaction of bearing outer ring and pedestal are considered. This model is different from the universal rubbing model, where the directions of relative motion between rotor and stator are not considered. Numerical integration method is used to obtain the response of the system where the rotor is established by FEM and the bearing outer ring and pedestal are established by lumped mass model. Firstly, modal test results and simulation results were used to verify the correctness of this model. Secondly, the role of tightening torque between bearing outer ring and pedestal is considered, and the response characteristics of bearing and rotor are analyzed when fit looseness fault is considered. Finally, comparing the simulation results with test results, the waveform and spectrum are similar, which verifies the correctness of the fit looseness model. The fit looseness fault characteristics are that the acceleration after noise reduction shows periodic impact, up and down asymmetry, multiple frequencies appear. A method by increasing tightening torque is put forward to control the vibration caused by fit looseness fault.

Data-driven model identification and predictive control for path-following of underactuated ships with unknown dynamics

Wang Le,Li Shijie,Liu Jialun,Wu Qing 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

With the trends towards autonomous shipping, advanced ship motion control methods have received increased attention in recent years. The validity of ship models is crucial in designing motion controllers and directly affects their performances. However, accurate models that could reflect true ship dynamics are highly nonlinear, complex and complicated to identify, especially in situations when the experimental conditions are limited. This paper proposes a data-driven predictive control method for pathfollowing of under-actuated cargo ships with unknown dynamics, which makes use of data gathered during operation to improve the model and the path-following performance. Based on the ship navigation data set, the relations between the heading angle and the rudder angle of the ship are fitted with seven typical regression algorithms, which acts as the prediction model in the path-following controller. Simulation study is carried out to choose the most suitable regression algorithm, among which elastic net regression is selected. The Antenna Mutation Beetle Swarm Predictive (AMBS-P) algorithm is introduced to find the optimal weights in the model identification process. A Line-of-Sight (LOS) algorithm is used as the guidance law to transform reference way-points into reference heading angles, and the path-following controller is designed also based on and the AMBS-P algorithm. Simulation results show that the proposed data-driven control method performs well in the path-following task without having prior knowledge regarding the hydrodynamic coefficients and ship parameters.

Determination Method for the Strength Model of a Jointed Rock Mass Based on the Geological Strength Index

Shijie Sun,Maolin Tian,Hongtian Xiao,Ying Wang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.7

The mechanical characteristics of materials are the key to numerical calculation, thedetermination of material parameters of jointed rock mass is conundrum in academia. For thepurpose of more efficiently and accurately select the mechanical parameters of the jointedrock masses, in this paper, a new method is proposed which for constructing a numericalmodel of jointed rock masses, which based on the Geological Strength Index (GSI) and theprinciples of damage mechanics. With the help of basic concepts of damage mechanics, thejoint equivalent coefficient is proposed, establishing the relationship between GSI and jointspacing. The selection way for the mechanical parameters of a jointed rock masses is given incombination with the Hoek-Brown strength criterion. Then, a numerical calculation model isconstructed by utilizing 3DEC numerical simulation software to discuss the stability of theadjoining rock under the condition of different GSIs, which is successfully applied to theWangjialing coal mine project. The numerical results match quite closely with the fieldconditions, the maximum error is 18%, the minimum error is 5.6%, verifying the rationalityand accuracy of this way and providing a new way for the accurate numerical simulation ofjointed rock masses.

Effects of low dietary cation-anion difference induced by ruminal ammonium chloride infusion on performance, serum, and urine metabolites of lactating dairy cows

Wang, Kun,Nan, Xuemei,Zhao, Puyi,Liu, Wei,Drackley, James K.,Liu, Shijie,Zhang, Kaizhan,Bu, Dengpan Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.5

Objective: The objective of the present study was to determine ammonium chloride tolerance of lactating dairy cows, by examining effects of negative dietary cation anion difference (DCAD) induced by ruminal ammonium chloride infusion on performance, serum and urine minerals, serum metabolites and enzymes of lactating dairy cows. Methods: Four primiparous lactating Chinese Holstein cows fitted with ruminal cannulas were infused with increasing amounts (0, 150, 300, or 450 g/d) of ammonium chloride in a crossover design. The DCAD of the base diet was 279 mEq/kg dry matter (DM) using the DCAD formula (Na + K - Cl - S)/kg of DM. Ammonium chloride infusion added the equivalent of 0, 128, 330, and 536 mEq/kg DM of Cl in treatments. According to the different dry matter intakes (DMI), the resulting actual DCAD of the four treatments was 279, 151, -51, and -257 mEq/kg DM, respectively. Results: DMI decreased linearly as DCAD decreased. Yields of milk, 4% fat-corrected milk, energy-corrected milk, milk fat, and milk protein decreased linearly as DCAD decreased. Concentrations of milk protein and milk urea nitrogen increased linearly with decreasing DCAD. Concentration of Cl- in serum increased linearly and concentration of PO43- in serum increased quadratically as DCAD decreased. Urine pH decreased linearly and calculated urine volume increased linearly with decreasing DCAD. Linear increases in daily urinary excretion of $Cl^-$, $Ca^{2+}$, $PO_4{^{3-}}$, urea N, and ammonium were observed as DCAD decreased. Activities of alanine aminotransferase, aspartate aminotransferase, and ${\gamma}-glutamyl$ transferase in serum and urea N concentration in serum increased linearly as DCAD decreased. Conclusion: In conclusion, negative DCAD induced by ruminal ammonium chloride infusion resulted in a metabolic acidosis, had a negative influence on performance, and increased serum enzymes indicating potential liver and kidney damage in lactating dairy cows. Daily ammonium chloride intake by lactating dairy cows should not exceed 300 g, and 150 g/d per cow may be better.