Abstract To simulate excitation response of the aircraft structural of flutter test aircraft under different excitation methods. A simulation method for excitation response of flutter flight tests ...based on finite element models has been proposed. This method is based on the finite element model of the aircraft structure. Establish aerodynamic and excitation force models for flutter flight tests. Obtain a simulation model for the excitation response of aircraft flutter flight tests. Solve the model and simulate various excitation methods for flutter flight tests. Firstly, a detailed introduction was given to the excitation modeling method for aircraft flutter flight tests, including two excitation models: external excitation and control surface excitation. Then, the finite element model of the structural dynamics of a single wing with ailerons is taken as the research object. Establish a single wing flutter flight test excitation response model. Implemented simulation of control surface sweep excitation, control surface pulse excitation, and small rocket excitation. The feasibility of this method has been verified. Finally, based on the finite element model of the entire aircraft, a flutter flight test excitation response simulation model was established. We have conducted analysis and research on sensor position optimization, excitation method optimization, excitation response amplitude prediction, and flutter boundary prediction. And the simulation optimization analysis results were compared with the flight test results. Analyzed the promoting effect of flutter flight test excitation response simulation on flight tests.
A
bstract
We study the holographic complexity of noncommutative field theories. The four-dimensional
N
=
4
noncommutative super Yang-Mills theory with Moyal algebra along two of the spatial ...directions has a well known holographic dual as a type IIB supergravity theory with a stack of D3 branes and non-trivial NS-NS B fields. We start from this example and find that the late time holographic complexity growth rate, based on the “complexity equals action” conjecture, experiences an enhancement when the non-commutativity is turned on. This enhancement saturates a new limit which is exactly 1/4 larger than the commutative value. We then attempt to give a quantum mechanics explanation of the enhancement. Finite time behavior of the complexity growth rate is also studied. Inspired by the non-trivial result, we move on to more general setup in string theory where we have a stack of D
p
branes and also turn on the B field. Multiple noncommutative directions are considered in higher
p
cases.
Multidimensional phase singularities in nanophotonics Ni, Jincheng; Huang, Can; Zhou, Lei-Ming ...
Science (American Association for the Advancement of Science),
2021-Oct-22, 2021-10-22, 20211022, Letnik:
374, Številka:
6566
Journal Article
Recenzirano
Rapid progress in miniaturizing vortex devices is driven by their integration with optical sensing, micromanipulation, and optical communications in both classical and quantum realms. Many such ...efforts are usually associated with on-chip micro- or nanoscale structures in real space and possess a static orbital angular momentum. Recently, a new branch of singular optics has emerged that seeks phase singularities in multiple dimensions, realizing vortex beams with compact nanodevices. Here, we review the topological phase singularities in real space, momentum space, and the spatiotemporal domain for generating vortex beams; discuss recent developments in theoretical and experimental research for generation, detection, and transmission of vortex beams; and provide an outlook for future opportunities in this area, ranging from fundamental research to practical applications.
Water electrolysis, driven by renewable energy resources, is a promising energy conversion technology that has gained intensive interest in recent years. However, conventional water electrolysis ...faces a number of challenges, including large thermodynamic potential gaps, valueless anodic products, explosive hydrogen/oxygen mixtures, reactive oxygen species, and limited pure water. Hybrid water electrolysis, appending different electrolytes in the anode compartment to circumvent the above‐mentioned challenges in conventional water electrolysis, is a particularly attractive alternative. In this review, for the first time, a holistic and subtle description of hybrid water electrolysis is provided, focusing on the design of high‐activity/selectivity/stability anodic electrocatalysts for the electrochemical oxidation of various chemicals, such as alcohol, aldehyde, amine, urea and hydrazine, or the oxygen evolution reaction in seawater electrolytes. Comprehensive judging criteria for anodic oxidation reactions, electrocatalysts, and reaction parameters in hybrid water electrolysis are discussed. Some technoeconomic assessments, feasibility analyses, mechanism explorations, and correlation comparisons are involved. Finally, perspectives on and opportunities for future research directions in hybrid water electrolysis systems are outlined.
Hybrid water electrolysis can circumvent the challenges of conventional water electrolysis and show several advantages, including energy efficiency, cost, and safety. Based on the considerations of alternative oxidation reactions, electrocatalysts and reaction parameters for hybrid water electrolysis, several judging criteria are proposed.
Branched-chain amino acid (BCAA) metabolism is potentially linked with development of pancreatic ductal adenocarcinoma (PDAC)
. BCAA transaminase 2 (BCAT2) was essential for the collateral lethality ...conferred by deletion of malic enzymes in PDAC and the BCAA-BCAT metabolic pathway contributed to non-small-cell lung carcinomas (NSCLCs) other than PDAC
. However, the underlying mechanism remains undefined. Here we reveal that BCAT2 is elevated in mouse models and in human PDAC. Furthermore, pancreatic tissue-specific knockout of Bcat2 impedes progression of pancreatic intraepithelial neoplasia (PanIN) in LSL-Kras
; Pdx1-Cre (KC) mice. Functionally, BCAT2 enhances BCAA uptake to sustain BCAA catabolism and mitochondrial respiration. Notably, BCAA enhances growth of pancreatic ductal organoids from KC mice in a dose-dependent manner, whereas addition of branched-chain α-keto acid (BCKA) and nucleobases rescues growth of KC organoids that is suppressed by BCAT2 inhibitor. Moreover, KRAS stabilizes BCAT2, which is mediated by spleen tyrosine kinase (SYK) and E3 ligase tripartite-motif-containing protein 21 (TRIM21). In addition, BCAT2 inhibitor ameliorates PanIN formation in KC mice. Of note, a lower-BCAA diet also impedes PDAC development in mouse models of PDAC. Thus, BCAT2-mediated BCAA catabolism is critical for development of PDAC harbouring KRAS mutations. Targeting BCAT2 or lowering dietary BCAA may have translational significance.
A
bstract
In the past, the study of the divergence structure of the holographic entanglement entropy on singular boundary regions uncovered cut-off independent coefficients. These coefficients were ...shown to be universal and to encode important field theory data. Inspired by these lessons we study the UV divergences of subregion complexity-action (CA) in a region with corner (kink). We develop a systematic approach to study all the divergence structures, and we emphasize that the counter term that restores reparameterization invariance on the null boundaries plays a crucial role in simplifying the results and rendering them more transparent. We find that a general form of subregion CA contains a part dependent on the null generator normalizations and a part that is independent of them. The former includes a volume contribution as well as an area contribution. We comment on the origin of the area term as entanglement entropy, and point out that its presence constitutes a robust difference between the two prescriptions to calculate subregion complexity (-action vs. -volume). We also find universal log
δ
divergence associated with the kink feature of the subregion. Similar flat angle limit as the subregion-CV result is obtained.
Circular RNAs (circRNAs) are a new class of non-coding RNAs formed by covalently closed loops through backsplicing. Recent methodologies have enabled in-depth characterization of circRNAs for ...identification and potential functions. CircRNAs play important roles in various biological functions as microRNA sponges, transcriptional regulators and combining with RNA binding proteins. Recent studies indicated that some cytoplasmic circRNAs can be effectively translated into detectable peptides, which enlightened us on the importance of circRNAs in cellular physiology function. Internal Ribosome Entry site (IRES)- and N
-methyladenosines (m
A)-mediated cap-independent translation initiation have been suggested to be potential mechanism for circRNA translation. To date, several translated circRNAs have been uncovered to play pivotal roles in human cancers. In this review, we introduced the properties and functions of circRNAs, and characterized the possible mechanism of translation initiation and complexity of the translation ability of circRNAs. We summarized the emerging functions of circRNA-encoded proteins in human cancer. The works on circRNA translation will open a hidden human proteome, and enhance us to understand the importance of circRNAs in human cancer, which has been poorly explored so far.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Rotating traversable wormholes in AdS Caceres, Elena; Misobuchi, Anderson Seigo; Xiao, Ming-Lei
The journal of high energy physics,
12/2018, Letnik:
2018, Številka:
12
Journal Article
Recenzirano
Odprti dostop
A
bstract
In this work we explore the effect of rotation in the size of a traversable wormhole obtained via a double trace boundary deformation. We find that at fixed temperature
the size of the ...wormhole increases with the angular momentum J/M ℓ
. The amount of information that can be sent through the wormhole increases as well. However, for the type of interaction considered, the wormhole closes as the temperature approaches the extremal limit. We also briefly consider the scenario where the boundary coupling is not spatially homogeneous and show how this is reflected in the wormhole opening.
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