In this paper, we propose a ghost imaging scheme with fast Walsh–Hadamard transform, named GIFWHT. In the scheme, Walsh–Hadamard pattern pairs are used to illuminate an object to generate pairs of ...detection results, and the corresponding differential detection result is used as the result as that from the conventional bucket detector.By performing the fast Walsh–Hadamard transform on 2~k(k is a positive integer) differential detection results,the image of the object can be recovered. The experimental and numerical simulation results show that the reconstruction time of GIFWHT is greatly reduced, and the quality of the recovered image is noticeably improved. In addition, GIFWHT is robust against interference from environmental illumination and could save memory.
Background
Tai chi is considered a safe and low‐cost treatment for improving balance ability among an older population. However, there is no existing evidence on the optimal exercise parameters of ...tai chi for improving balance in older adults.
Objectives
To investigate the optimal parameters of a tai chi intervention to improve balance performance of older adults.
Design
Systematic review and meta‐analysis of randomized controlled trials (RCTs).
Setting
PubMed, Embase, Cochrane Library, Web of Science, Scopus, China National Knowledge Infrastructure, Wanfang, Chinese Science and Technology Periodical and China Biology Medicine were searched from inception until November 30, 2020.
Participants
Adults aged 60 years and over.
Measurements
Two reviewers independently extracted the data and assessed the quality of the included studies according to the Physiotherapy Evidence Database (PEDro) scale. Subgroup analyses and meta‐regressions were conducted to elucidate the impact of tai chi training programs on balance measures.
Results
Twenty‐six eligible RCTs were included in the meta‐analysis. Pooled results showed that tai chi has moderate effects for improving proactive balance (weighted mean standardized mean differences SMDwm = 0.61, 95% CI 0.33–0.89) and static steady‐state balance (SMDwm = 0.62, 95% CI 0.30–0.95) and small effects for improving dynamic steady‐state balance (SMDwm = 0.38, 95% CI 0.03–0.73) and balance test batteries (SMDwm = 0.47, 95% CI 0.13–0.81) in adults over 60 years of age. The practice frequency could predict the effects of tai chi on static steady‐state balance, and the 24‐form simplified Yang style tai chi (45–60 min/session, more than four sessions per week and at least 8 weeks) was the most optimal.
Conclusions
Tai chi is effective at improving the balance ability of adults over 60 years of age. A medium duration and high frequency of 24‐form tai chi may be the optimal program for improving balance, but this evidence should be recommended with caution due to limitations of the methodology and small sample sizes.
A weak alkaline condition (pH > 8) is a general requirement for oxidative self-polymerization of dopamine. Here, we first demonstrated the generation of polydopamine in an acidic environment via a ...hydrothermal method. The pH scope of self-polymerization of dopamine is extended to pH ∼ 1 in a hydrothermal process. Polydopamine generated via a hydrothermal method shows similar chemical features and radical scavenging activity with that generated in a basic environment.
Ethers are of central importance in the fields of biomass, energy, and organic chemistry. Herein, a novel cobalt‐catalyzed carbonylative coupling of ethers with amines to construct α‐carbonylated ...ethers has been achieved. Remarkably, Alfuzosin, a medicine for treatment of benign prostatic hyperplasia (BPH), can be synthesized by this process straightforwardly. Notably, this protocol presents the first example on the direct carbonylative reaction of ethers.
A novel cobalt‐catalyzed carbonylative coupling of ethers with amines to construct α‐carbonylated ethers has been achieved. Alfuzosin, a medicine for treatment of benign prostatic hyperplasia (BPH), can be synthesized by this process straightforwardly.
In spite of the recent interest and advances in linear controllability of complex networks, controlling nonlinear network dynamics remains an outstanding problem. Here we develop an experimentally ...feasible control framework for nonlinear dynamical networks that exhibit multistability. The control objective is to apply parameter perturbation to drive the system from one attractor to another, assuming that the former is undesired and the latter is desired. To make our framework practically meaningful, we consider restricted parameter perturbation by imposing two constraints: it must be experimentally realizable and applied only temporarily. We introduce the concept of attractor network, which allows us to formulate a quantifiable controllability framework for nonlinear dynamical networks: a network is more controllable if the attractor network is more strongly connected. We test our control framework using examples from various models of experimental gene regulatory networks and demonstrate the beneficial role of noise in facilitating control.
Abstract
Spin-orbit coupled honeycomb magnets with the Kitaev interaction have received a lot of attention due to their potential of hosting exotic quantum states including quantum spin liquids. Thus ...far, the most studied Kitaev systems are 4
d
/5
d
-based honeycomb magnets. Recent theoretical studies predicted that 3
d
-based honeycomb magnets, including Na
2
Co
2
TeO
6
(NCTO), could also be a potential Kitaev system. Here, we have used a combination of heat capacity, magnetization, electron spin resonance measurements alongside inelastic neutron scattering (INS) to study NCTO’s quantum magnetism, and we have found a field-induced spin disordered state in an applied magnetic field range of 7.5 T <
B
(⊥
b
-axis) < 10.5 T. The INS spectra were also simulated to tentatively extract the exchange interactions. As a 3
d
-magnet with a field-induced disordered state on an effective spin-1/2 honeycomb lattice, NCTO expands the Kitaev model to 3
d
compounds, promoting further interests on the spin-orbital effect in quantum magnets.
In this study, we explore the fractional Zakharov system using the M-truncated derivative for the first time. Some new solitary wave and periodic solutions are derived for the fractional Zakharov ...equations through two advanced mathematical techniques: the fractional sine–Gordon expansion method and the fractional rational sine–cosine method. The obtained solutions are new to the fractional Zakharov equations that have not been reported in the previous literature. Visual representations of the solutions are provided using 3D and 2D graphical illustrations, offering insights relevant to associated physics and engineering disciplines. Notably, the proposed methodologies are streamlined, straightforward, and effective, holding promise for addressing various fractional evolution equations.
Effort has been devoted to automatic or semi-automatic individual tree detection and crown delineation from remotely sensed data, aiming at the effective creation of forest inventory, to assist ...forest management and ecosystem modelling. However, there is no uniform evaluation scheme to assess the resulting products. This paper reviews the available techniques and essential considerations for evaluating remote sensing-based forest inventory products, including detected individual tree locations, crown delineation maps, forest structure parameters, and species classification results. The reference data collection, individual tree matching method, mismatched individual tree crown treatment, and stratification criteria are summarized as four key factors in the evaluation process. Additionally, a discussion of future working directions, regarding limitations of existing techniques, multi-scale evaluation, sampling schemes, uncertainty analysis, and results interpretation, is also included. A new accuracy assessment framework is proposed, and an accuracy report example is provided.
An FeCl3-mediated cascade coupling/decarbonylative annulation reaction for the efficient construction of 2-(trifluoromethyl)quinazolin-4(3H)-ones has been developed. This transformation employs ...readily available isatins and trifluoroacetimidoyl chlorides as the starting materials, providing a facile and practical route to diverse biologically relevant quinazolin-4(3H)-one derivatives. A plausible reaction pathway has been proposed based on the mechanistic observations.
A low cost FeCl3‐mediated cascade annulation of trifluoroacetimidoyl chlorides and hydrazides for the efficient synthesis of 5‐trifluoromethyl‐1,2,4‐triazoles has been developed. The transformation ...proceeds through a cascade base‐promoted intermolecular C−N bond formation and FeCl3‐mediated intramolecular dehydration sequence under mild conditions. The protocol exhibits many notable features and can be readily scaled up to gram scale.
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