14 research outputs found
Fatigue Strength Assessment of Semi-Submersible Floating Wind Turbine Foundation under Turbulent Wind
Under the complex marine environment load and the role of the upper wind turbine load, deep sea floating wind turbine support structure would suffer fatigue damage, which often endangers the safety of the wind turbine system. This paper chose the "5 MW baseline" wind turbine model which published by the US National Renewable Energy Laboratory (NREL) as the design basis. The paper uses the OC4-DeepC wind semi-submersible offshore wind turbine model for the verification of offshore floating wind turbines. According to the characteristics of stress and the distribution of stress, the paper selects seven key parts which are prone to fatigue damage are screened, respectively established local finite element models and carried out grid encryption. Based on the SESAM hydrodynamic analysis software and FAST wind motor dynamic load calculation procedure, the fatigue damage of the target node under the action of wind turbine load is studied. The results show that the structural fatigue damage occurs mainly at the horizontal connection of the upper part of the neutral column and the diagonal connection of the lower part of the neutral column. The fatigue damage degree of the crown and the saddle point is relatively large at the connecting rod position
Effects of sand burial and overstory tree age on seedling establishment in coastal Pinus thunbergii forests in the northern Shandong Peninsula, China
Novel D–A−π–A-Type Organic Dyes Containing a Ladderlike Dithienocyclopentacarbazole Donor for Effective Dye-Sensitized Solar Cells
A novel
ladderlike fused-ring donor, dithienocyclopentacarbazole
(DTCC) derivative, is used to design and synthesize three novel donor–acceptor−π–acceptor-type
organic dyes (C1–C3) via facile direct arylation reactions,
in which the DTCC derivative substituted by four <i>p</i>-octyloxyphenyl groups is served as the electron donor and the carboxylic
acid group is used as the electron acceptor or anchoring group. To
fine-tune the optical, electrochemical, and photovoltaic properties
of the three dyes, various auxiliary acceptors, including benzoÂ[2,1,3]Âthiadiazole
(BT), 5,6-difluorobenzoÂ[2,1,3]Âthiadiazole (DFBT), and pyridalÂ[2,1,3]Âthiadiazole
(PT), are incorporated into the dye backbones. The results indicate
that all of the three dyes exhibit strong light-capturing ability
in the visible region and obtain relatively high molar extinction
coefficients (>31 000 M<sup>–1</sup> cm<sup>–1</sup>) due to their strong charge transfer (CT) from donor to acceptor.
Moreover, theoretical model calculations demonstrate fully separated
highest occupied molecular orbital and lowest unoccupied molecular
orbital energy levels for the three dyes, which is helpful for efficient
charge separation and electron injection. Using the three dyes as
sensitizers, conventional dye-sensitized solar cells (DSSCs) based
on liquid iodide/triiodide redox electrolytes are fabricated. Our
results indicate that the BT-containing dye C1 affords the highest
power conversion efficiency of up to 6.75%, much higher than that
of the DFBT-containing dye C2 (5.40%) and the PT-containing dye C3
(1.85%). To our knowledge, this is the first example reported in the
literature where the DTCC unit has been used to develop novel organic
dyes for DSSC applications. Our work unambiguously demonstrates that
the ladderlike DTCC derivatives are the superb electron-donating blocks
for the development of high-performance organic dye
Value of multi-slice spiral CT in diagnosis of malignant gastrointestinal stromal tumors
RACK1 Promotes Autophagy by Enhancing the Atg14L-Beclin 1-Vps34-Vps15 Complex Formation upon Phosphorylation by AMPK
Autophagy is essential for maintaining tissue homeostasis. Although adaptors have been demonstrated to facilitate the assembly of the Atg14L-Beclin 1-Vps34-Vps15 complex, which functions in autophagosome formation, it remains unknown whether the autophagy machinery actively recruits such adaptors. WD40-repeat proteins are a large, highly conserved family of adaptors implicated in various cellular activities. However, the role of WD40-repeat-only proteins, such as RACK1, in postnatal mammalian physiology remains unknown. Here, we report that hepatocyte-specific RACK1 deficiency leads to lipid accumulation in the liver, accompanied by impaired Atg14L-linked Vps34 activity and autophagy. Further exploration indicates that RACK1 participates in the formation of autophagosome biogenesis complex upon its phosphorylation by AMPK at Thr50. Thr50 phosphorylation of RACK1 enhances its direct binding to Vps15, Atg14L, and Beclin 1, thereby promoting the assembly of the autophagy-initiation complex. These observations provide insight into autophagy induction and establish a pivotal role for RACK1 in postnatal mammalian physiology