http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
OSCILLATION OF SECOND ORDER UNSTABLE NEUTRAL DIFFERENCE EQUATIONS WITH CONTINUOUS ARGUMENTS
TIAN, YU,ZHANG, ZHENGUO,GE, WEIGAO 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.20 No.1
In this paper, we consider the oscillation second order unstable neutral difference equations with continuous arguments $\Delta^2_{/tau}(\chi(t)-p\chi(t-\sigma))=f(t,\chi(g(t)))$ and obtain some criteria for the bounded solutions of this equation to be oscillatory.
PERIODIC SOLUTIONS FOR A QUASILINEAR NON-AUTONOMOUS SECOND-ORDER SYSTEM
Tian, Yu,Zhang, Guosheng,Ge, Weigao 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.22 No.1
In this paper, a quasilinear second-order system with periodic boundary conditions is studied. By the least action principle and classical theorems of variational calculus, existence results of periodic solutions are obtained.
MULTIPLE SOLUTIONS FOR CERTAIN NONLINEAR SECOND-ORDER SYSTEMS
Tian, Yu,Ge, Weigao 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.25 No.1
In this paper, we prove the existence of multiple solutions for Neumann and periodic problems. Our main tools are recent general multiplicity theorems proposed by B. Ricceri.
Tian, Yu‐,Hua,Hwan Kim, Seung,Lee, Seok‐,Yong,Jang, Choon‐,Gon Wiley Subscription Services, Inc., A Wiley Company 2011 Synapse Vol.65 No.10
<P><B>Abstract</B></P><P>The central nervous system is affected by polychlorinated biphenyls (PCBs). Previous studies have indicated that developmental exposure to PCBs impairs behavioral performance and alters cognitive abilities. This study assessed the effects of lactational and postnatal exposure to a commercial PCBs mixture, Aroclor 1254 (A1254), on mice performing several neurobehavioral tasks including the open field test, novel object test, elevated plus maze test, Y‐maze test, and tail suspension test. In the open field test, PCBs treatment (6 and 18 mg/kg/day) was associated with increased movement, time duration, and frequency in the central zone in female but not male mice. PCBs‐treated female mice (6 and 18 mg/kg/day) also showed decreased novel object recognition, indicating impairment in recognition memory. Finally, we performed autoradiographic receptor binding assays for dopamine (DA) D<SUB>1</SUB> and D<SUB>2</SUB> receptors, dopamine transporter (DAT), and the N‐methyl‐<SMALL>D</SMALL>‐aspartic acid (NMDA) receptor after behavioral tests to examine whether alterations occurred in the dopaminergic and NMDAergic systems of the brain. Our results showed that PCBs treatment did not change D<SUB>1</SUB> and D<SUB>2</SUB> receptors or DAT binding in the dorsal striatum of female mice. However, PCBs treatment significantly decreased NMDA receptor binding in the dorsal striatum, frontal cortex, cingulate cortex, and motor cortex, and CA3 and dentate gyrus (DG) of the hippocampus in female mice. Collectively, our results suggest that long‐term PCBs exposure can induce anxiolytic behavior, cognitive deficits, and changes of NMDA receptors. Synapse, 2011. © 2011 Wiley©Liss, Inc.</P>
Dynamic interaction analysis of vehicle-bridge system using transfer matrix method
Tianyu Xiang,Renda Zhao 국제구조공학회 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.20 No.1
The dynamic interaction of vehicle-bridge is studied by using transfer matrix method in this paper. The vehicle model is simplified as a spring-damping-mass system. By adopting the idea of Newmark-β method, the partial differential equation of structure vibration is transformed into a differential equation irrelevant to time. Then, this differential equation is solved by transfer matrix method. The prospective application of this method in real engineering is finally demonstrated by several examples.
Heart Failure Is Associated with Increased Risk of Long-Term Venous Thromboembolism
Tianyu Xu,Yuli Huang,Zuheng Liu,Yujia Bai,Zhuang Ma,Xiaoyan Cai,Yuhui Zhang,Jian Zhang 대한심장학회 2021 Korean Circulation Journal Vol.51 No.9
Background and Objectives: Venous thromboembolism (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE), is highly prevalent in in-hospital HF patients and contributes to worse prognoses. However, the risk of VTE in out-patients with HF in long-term period is controversial. This study aimed to evaluate the associations between HF and the risk of VTE in a long-term follow-up duration. Methods: We searched for studies investigating the risk of VTE, PE, and DVT in patients with HF before April 15, 2020, in PubMed, MEDLINE, and Embase databases. Cohort studies and post hoc analysis of RCTs were eligible for inclusion if they reported relative risk of VTE, DVT or PE in patients with HF in more than 3-month follow-up period. Results: We identified 31 studies that enrolled over 530,641 HF patients. Overall, patients with HF were associated with an increased risk of VTE (risk ratio [RR]=1.57, 95% confidence interval [CI]=1.34–1.84) and PE (RR=2.00, 95% CI=1.38–2.89). However, the risk of DVT was not significantly increased in HF patients (RR=1.33, 95% CI=0.67–2.63). Subgroup analysis showed that patients with chronic HF (RR=1.54, 95% CI=1.32–1.80) had a higher risk of VTE than those with acute HF (RR=0.95, 95% CI=0.68–1.32). Conclusions: In conclusion, HF was an independent risk for VTE and PE but not DVT in a long-term follow-up period. Patients with chronic HF were prone to suffer from VTE than acute HF.
Tianyu Zhang,Tong Li,Wei Hu,Weiqi Wang,Letian Zhang,Wenfa Xie 한국물리학회 2014 Current Applied Physics Vol.14 No.5
White organic light-emitting devices (WOLEDs) with fluorescent donor-acceptor-substituted spirobifluorene compounds (red 2-diphenylamino-7-(2,2-dicyanovinyl)-9,90-spirobifluorene and blue 2- diphenylamino-7-(2,2-diphenylvinyl)-9,90-spirobifluorene) have been fabricated. The optimized WOLEDs shows a maximum current efficiency 5.9 cd/A and very low efficiency roll-off. From the brightness at maximum current efficiency to high brightness of 10000 cd/m2, the current efficiency rolloff is only 0.4%. It can be attributed to the ambipolar blue fluorescent emitter with voltage-independnet mobility which makes the device having a broader charge recombination zone and balance of carrier transport.
Soft-Switching T-Type Multilevel Inverter
Tianyu Chen,Mehdi Narimani 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5
In order to improve the conversion efficiency and mitigate the EMI problem of conventional hard-switching inverters, a new soft-switching DC-AC inverter with a compact structure and a low modulation complexity is proposed in this paper. In the proposed structure, resonant inductors are connected in series for the arm branches, and resonant capacitors are connected in parallel for the neutral point branches. With the help of resonant components, the proposed structure achieves zero-current switching on the arm branches and zero-voltage switching on the neutral point branches. When compared with state-of-art soft-switching topologies, the proposed topology does not need auxiliary switches. Moreover, the commutation algorithm to realize soft-switching can be easily implemented. In this paper, the principle of the resonant operation of the proposed soft-switching converter is presented and its performance is verified through simulation studies. The feasibility of the proposed inverter is evaluated experimentally with a 2.4-kW prototype.
Dynamic analysis of thin-walled open section beam under moving vehicle by transfer matrix method
Tianyu Xiang,Tengfei Xu,Xinpeng Yuan,Renda Zhao,Yuqiang Tong 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.5
Three dimensional coupled bending-torsion dynamic vibrations of thin-walled open section beam subjected to moving vehicle are investigated by transfer matrix method. Through adopting the idea of Newmark-β method, the partial differential equations of structural vibration can be transformed to the differential equations. Then, those differential equations are solved by transfer matrix method. An iterative scheme is proposed to deal with the coupled bending-torsion terms in the governing vibration equations. The accuracy of the presented method is verified through two numerical examples. Finally, with different eccentricities of vehicle, the torsional vibration of thin-walled open section beam and vertical and rolling vibration of truck body are investigated. It can be concluded from the numerical results that the torsional vibration of beam and rolling vibration of vehicle increase with the eccentricity of vehicle. Moreover, it can be observed that the torsional vibration of thin-walled open section beam may have a significant nonlinear influence on vertical vibration of truck body.