Fractional Calculus Guidance Algorithm in a Hypersonic Pursuit-Evasion Game

Aiming at intercepting a hypersonic weapon in a hypersonic pursuit-evasion game, this paper presents a fractional calculus guidance algorithm based on a nonlinear proportional and differential guidance law. First, under the premise of without increasing the complexity degree of the guidance system against a hypersonic manoeuvering target, the principle that the differential signal of the line-of-sight rate is more sensitive to the target manoeuver than the line-of-sight rate is employed as the guidelines to design the guidance law. A nonlinear proportional and differential guidance law (NPDG) is designed by using the differential derivative of the line-of-sight rate from a nonlinear tracking differentiator. By using the differential definition of fractional calculus, on the basis of the NPDG, a fractional calculus guidance law (FCG) is proposed. According to relative motions between the interceptor and target, the guidance system stability condition with the FCG is given and quantitative values are also proposed for the parameters of the FCG. Under different target manoeuver conditions and noisy conditions, the interception accuracy and robustness of these two guidance laws are analysed. Numerical experimental results demonstrate that the proposed guidance algorithms effectively reduce the miss distance against target manoeuvers. Compared with the NPDG, a stronger robustness of the FCG is shown under noisy condition

Sex differences in the association between blood pressure and atrial fibrillation: A case-control study

BackgroundTo examine the association of hypertension (HBP) and its control with atrial fibrillation (AF) and how patient sex affects this association.Materials and methodsA case control study of patients admitted to our hospital from 2015 to 2019 was conducted. Patients were divided into subgroups according to their blood pressure (BP) levels and control status, in which odd ratios (OR) by sex for AF was estimated using a logistic regression model and restrictive cubic splines before and after propensity score matching.ResultsA total of 3,212 patients with AF and 8,307 without AF were investigated. Compared to patients with normal BP, patients with HBP had more AF [OR = 1.75 (1.52–2.02), OR = 2.66 (2.24–3.15), and OR = 4.30 (3.40–5.44) in patients with grade 1, 2, and 3 HBP, respectively]. In HBP patients with grade 3, the OR of AF was much higher in women than in men (OR = 7.15, 95% CI: 4.43–11.50 vs. OR = 2.48, 95% CI: 1.66–3.72). BP over 133.1/79.9 mmHg in men or 127.1/75.1 mmHg in women was positively associated with AF. In patients with HBP, uncontrolled BP was more associated with AF (OR = 3.00, 95% CI: 2.53–3.56), especially in women (OR = 3.09, 95% CI: 2.27–4.19). BP and prevalence of AF correlated with each other positively in patients admitted to a cardiology ward. Lowering BP to 145.1/85.8 mmHg in men or 140.5/82.5 mmHg in women led to less AF.ConclusionThere is more significant relationship between HBP and AF in female patients. A lower and individualized BP target may be formulated to prevent AF in women

Cellulose-Based Radiative Cooling and Solar Heating Powers Ionic Thermoelectrics

Cellulose opens for sustainable materials suitable for radiative cooling thanks to inherent high thermal emissivity combined with low solar absorptance. When desired, solar absorptance can be introduced by additives such as carbon black. However, such materials still shows high thermal emissivity and therefore performs radiative cooling that counteracts the heating process if exposed to the sky. Here, this is addressed by a cellulose-carbon black composite with low mid-infrared (MIR) emissivity and corresponding suppressed radiative cooling thanks to a transparent IR-reflecting indium tin oxide coating. The resulting solar heater provides opposite optical properties in both the solar and thermal ranges compared to the cooler material in the form of solar-reflecting electrospun cellulose. Owing to these differences, exposing the two materials to the sky generated spontaneous temperature differences, as used to power an ionic thermoelectric device in both daytime and nighttime. The study characterizes these effects in detail using solar and sky simulators and through outdoor measurements. Using the concept to power ionic thermoelectric devices shows thermovoltages of &amp;gt;60 mV and 10 degrees C temperature differences already at moderate solar irradiance of approximate to 400 W m(-2).Funding Agencies|Wallenberg Wood Science Center; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Swedish Research Council [2018-04037, 2020-00287]; Knut and Alice Wallenberg Foundation; Linkoeping University</p

Phosphorus modified carbon fiber cloth as a robust and efficient anode for alkaline water electrolysis

Developing cost-effective electrocatalysts is critical to renewable energy conversion and storage technologies. In this work, commercial carbon fiber cloth (CFC) was thermally treated with PCl3 in a sealed-tube reactor to obtain phosphorus-modified CFC (P-CFC). The P-CFC can deliver an oxygen evolution reaction (OER) current density of 10 mA cm−2 with only 310 mV overpotential for 50 h with negligible activity decay, which is superior to all other reported metal-free OER electrocatalysts. The mechanism of improved OER activity was systematically studied by electron microscopy and photoelectron spectroscopy. It was found that the p-type doping on the CFC surface by P atom could promote the electron transfer from OH− to the electrode; moreover, the formation of oxidized C–P active sites under anodic potential boosted OER activity both thermodynamically and kinetically. This work not only develops a highly active metal-free OER electrocatalyst but also introduces a promising method to enhance the durability of carbon support for oxidative electrochemical reactions.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)We would like to acknowledge the financial support from the National Natural Science Foundation of China (No. 22075195), the Jiangsu Specially-Appointed Professor program, the starting research fund of Suzhou University of Science and Technology to Dr. Hong Bin Yang, the Singapore Ministry of Education Academic Research Fund (AcRF) Tier 1: RG115/18 and RG4/20, Tier 2: MOE2016-T2-2-004, and MOET2EP10120-0009, the Agency for Science, Technology and Research (A*Star) AME IRG: 192E5001, and the State Grid Cooperation of China (SGRI-DL-71-16-015)

Data_Sheet_1_Sex differences in the association between blood pressure and atrial fibrillation: A case-control study.DOCX

BackgroundTo examine the association of hypertension (HBP) and its control with atrial fibrillation (AF) and how patient sex affects this association.Materials and methodsA case control study of patients admitted to our hospital from 2015 to 2019 was conducted. Patients were divided into subgroups according to their blood pressure (BP) levels and control status, in which odd ratios (OR) by sex for AF was estimated using a logistic regression model and restrictive cubic splines before and after propensity score matching.ResultsA total of 3,212 patients with AF and 8,307 without AF were investigated. Compared to patients with normal BP, patients with HBP had more AF [OR = 1.75 (1.52–2.02), OR = 2.66 (2.24–3.15), and OR = 4.30 (3.40–5.44) in patients with grade 1, 2, and 3 HBP, respectively]. In HBP patients with grade 3, the OR of AF was much higher in women than in men (OR = 7.15, 95% CI: 4.43–11.50 vs. OR = 2.48, 95% CI: 1.66–3.72). BP over 133.1/79.9 mmHg in men or 127.1/75.1 mmHg in women was positively associated with AF. In patients with HBP, uncontrolled BP was more associated with AF (OR = 3.00, 95% CI: 2.53–3.56), especially in women (OR = 3.09, 95% CI: 2.27–4.19). BP and prevalence of AF correlated with each other positively in patients admitted to a cardiology ward. Lowering BP to 145.1/85.8 mmHg in men or 140.5/82.5 mmHg in women led to less AF.ConclusionThere is more significant relationship between HBP and AF in female patients. A lower and individualized BP target may be formulated to prevent AF in women.</p

Nanosized CoO Loaded on Copper Foam for High-Performance, Binder-Free Lithium-Ion Batteries

The synthesis of nanosized CoO anodes with unique morphologies via a hydrothermal method is investigated. By adjusting the pH values of reaction solutions, nanoflakes (CoO-NFs) and nanoflowers (CoO-FLs) are successfully located on copper foam. Compared with CoO-FLs, CoO-NFs as anodes for lithium ion batteries present ameliorated lithium storage properties, such as good rate capability, excellent cycling stability, and large CoO nanoflakes; CoO nanoflowers; anodes; binder free; lithium ion batteriesreversible capacity. The initial discharge capacity is 1470 mA h g−1, while the reversible capacity is maintained at 1776 m Ah g−1 after 80 cycles at a current density of 100 mA h g−1. The excellent electrochemical performance is ascribed to enough free space and enhanced conductivity, which play crucial roles in facilitating electron transport during repetitive Li+ intercalation and extraction reaction as well as buffering the volume expansion

Engineering single-atom electrocatalysts for enhancing kinetics of acidic Volmer reaction

The design of active and low-cost electrocatalyst for hydrogen evolution reaction (HER) is the key to achieving a clean hydrogen energy infrastructure. The most successful design principle of hydrogen electrocatalyst is the activity volcano plot, which is based on Sabatier principle and has been used to understand the exceptional activity of noble metal and design of metal alloy catalysts. However, this application of volcano plot in designing single-atom electrocatalysts (SAEs) on nitrogen doped graphene (TM/N4C catalysts) for HER has been less successful due to the nonmetallic nature of the single metal atom site. Herein, by performing ab initio molecular dynamics simulations and free energy calculations on a series of SAEs systems (TM/N4C with TM = 3d, 4d, or 5d metals), we find that the strong charge-dipole interaction between the negatively charged *H intermediate and the interfacial H2O molecules could alter the transition path of the acidic Volmer reaction and dramatically raise its kinetic barrier, despite its favorable adsorption free energy. Such kinetic hindrance is also experimentally confirmed by electrochemical measurements. By combining the hydrogen adsorption free energy and the physics of competing interfacial interactions, we propose a unifying design principle for engineering the SAEs used for hydrogen energy conversion, which incorporates both thermodynamic and kinetic considerations and allows going beyond the activity volcano model.This work is financially supported by NSFC (Grant 22022504) of China, Guangdong “Pearl River” Talent Plan (Grant 2019QN01L353), Shenzhen Science and Technology Program (Grant JCYJ20210324103608023), and Guangdong Provincial Key Laboratory of Catalysis (Grant 2020B121201002). B.L. acknowledges the financial support from City University of Hong Kong startup fund. The XAS measurement was performed at Shanghai Synchrotron Radiation Facility by Prof. Xiaozhi Su and was supported by NSFC (Grant 22102207) of China

Switchable Broadband Terahertz Absorbers Based on Conducting Polymer-Cellulose Aerogels

Terahertz (THz) technologies provide opportunities ranging from calibration targets for satellites and telescopes to communication devices and biomedical imaging systems. A main component will be broadband THz absorbers with switchability. However, optically switchable materials in THz are scarce and their modulation is mostly available at narrow bandwidths. Realizing materials with large and broadband modulation in absorption or transmission forms a critical challenge. This study demonstrates that conducting polymer-cellulose aerogels can provide modulation of broadband THz light with large modulation range from approximate to 13% to 91% absolute transmission, while maintaining specular reflection loss &amp;lt; -30 dB. The exceptional THz modulation is associated with the anomalous optical conductivity peak of conducting polymers, which enhances the absorption in its oxidized state. The study also demonstrates the possibility to reduce the surface hydrophilicity by simple chemical modifications, and shows that broadband absorption of the aerogels at optical frequencies enables de-frosting by solar-induced heating. These low-cost, aqueous solution-processable, sustainable, and bio-friendly aerogels may find use in next-generation intelligent THz devices.Funding Agencies|Swedish Research Council(VR); Swedish Foundation for Strategic Research (SSF); Stellenbosch Institute for Advanced Study (STIAS); Swedish Foundation for International Cooperation in Research and Higher Education (STINT); Knut and Alice Wallenberg Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkping University [61831012]; National Natural Science Foundation of China (NFSC) [62131006, 52003202, 2023YFB381130005, 2021JDTD0026, 2023JDGD0012]; National Key Research and Development Program of China [2019-252]; Sichuan Province Science and Technology Support Program [2020-00287, 2022-00211]; Guangdong Science and Technology Major Special Fund [2022-06214]; Wallenberg Wood Science Center; [2009 00971]; [62311530115]; [62235004]</p