Adaptive control of nonlinear time-delay system with low triangular structure is considered in this paper. Based on Lyapunov stability theory and Lyapunov-Krasovskii functional, an adaptive controller was proposed by the backstepping technique and parameter estimation method. The adaptive controller can make the closed-loop system uniformly asymptotically stable.
The Zheduo–Gongga Mountain, an enormous tower located at the boundary of the eastern Tibetan Plateau, is an ideal place to study the contribution of the climate and/or tectonics to the mountain building. Here, we report new zircon U–Pb ages, biotite 40Ar–39Ar, and apatite fission track (AFT) ages of granites along the Zhonggu transect in the northern part of the Zheduo–Gongga massif to investigate the detailed exhumation history and mechanism. The results show zircon U-Pb ages of 14.3 ± 0.3 and 11.3 ± 0.2 Ma, Biotite 40Ar–39Ar ages of 4.39 ± 0.07 and 3.62 ± 0.05 Ma, and AFT ages of ~2.6–0.9 Ma. Combining previous structural and geochronological studies, we argue that the growth and exhumation of the Zheduo–Gongga Mountain experienced the following stages. Late Oligocene–early Miocene crust shortening and magmatism marked the initiation of the crustal thickening and surface uplift during ~32–11 Ma, forming a migmatite–granitic belt along the Xianhuihe fault, in response to the northward advancing of the Indian plate into the Eurasian plates. Subsequently, the massif experienced episodic phases of exhumation with variable rates. The exhumation occurred at a rate of ~1–1.5 km/Ma with a cooling rate of 70 ± 20 °C/m.y. during ~11–5 Ma coinciding with the coeval intensification of the Asian monsoon and clockwise rotation of the Chuandian block, south of the Xianshuihe fault. During ~5–2 Ma, a phase of accelerated exhumation (~2–5 km/Ma) started, followed by a possible phase of decelerated exhumation (~1–1.5 km/Ma, corresponding to a cooling rate of 120 ± 20 °C/m.y.) since ~2 Ma, when alpine glaciations initiated due to global cooling. This study highlights the importance of tectonic deformation during ~11–5 Ma in controlling the early growth and exhumation of high mountains in the eastern Tibetan Plateau. The climate may account for the later exhumation of the Zheduo–Gongga mountain since ~5 Ma.
In the title co-crystal, C10H11NO2·C10H13NO2, the carboxylic acid moiety uses its acid H atom as the donor atom to bind strongly to the negatively charged O atom of the zwitterionic moiety [O⋯O = 2.557 (2) Å]. Meanwhile, the protonated N atom of the zwitterionic moiety forms a hydrogen bond with the double-bonded O atom of an adjacent zwitterionic moiety [N⋯O = 2.703 (2) Å] to give rise to a linear chain motif. The butenyl substituent (on the zwitterion) is disordered with respect to a butyl group and the butyl substituent (on the neutral molecule) is disordered with respect to a butenyl group, the site occupancy for both being in an approximate 0.6:0.4 ratio.
Objective To investigate the possible mechanism of oxidative stress in the high free fatty acids(FFA)-induced hypertension.Methods Male Sprague-Dawley(SD)rat models were established and classified into three groups:control group(NC group,n=20),FFA group(n=22),and N-acetylcysteine group(NAC group,n=23).NC group received a 4h infusion of saline(18 μL/min),FFA group received a 4h infusion of 20% fat emulsion(intralipid,18 μL/min)+ heparin(0.72 U/min),and NAC group received a 4h infusion of intralipid(18 μL/min)+ heparin(0.72 U/min)and NAC [2.76 μmol/(kg·min)].Blood pressure was recorded using intraarterial recording method.The hyperinsulinemic-euglycemic clamp technique was performed to investigate insulin resistance.An organ chamber experiment was performed to determine endothelium-dependent vasodilation(EDV)or endothelium-independent vasodilation(EIV).FFAs,reactive oxygen species(ROS),glutataione(GSH)and NO2-/NO3-levels in plasma were measured.Endothelial nitric oxide synthase(eNOS)mRNA expression in endothelial cells was evaluated by real time fluorescence-PCR.Results In FFA group,after 4 h infusion of the intralipid+heparin,systolic and diastolic blood pressure were increased by(11.5±2.2)and(6.0±1.2)mm Hg respectively(P0.05).In NAC group,systolic and diastolic blood pressure remained the same.The GIR was decreased significantly in FFA group compared with NC group [(5.3±0.6)vs(13.4±0.5)mg/(kg·min),P0.05].In FFA group,the aortic rings tended to demonstrate impaired EDV in response to acetylcholine(ACh)(P0.05).There was no difference of EDV response in NAC and NC group.ROS concentrations in FFA group were higher than that in NC group(P0.05)and GSH concentrations were lower than that in NC group(P0.05).In FFA group,NO2-/NO3-levels were significantly reduced(P0.05)and eNOS mRNA expression was significantly decreased by 41.2% compared with NC group.NAC administration increased NO2-/NO3-levels(P0.05)and eNOS mRNA expression was significantly increased by 30.5% compared with FFA group.Conclusion Elevated FFAs can induce blood pressure elevated,potentially through FFA-induced impairment of EDV resulting from decreased eNOS mRNA expression.Oxidative stress may also play an important role in the mechanisms of this high FFA-induced elevated BP.
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