The recent theory-orientated discovery of record high-temperature superconductivity (Tc∼250 K) in sodalitelike clathrate LaH10 is an important advance toward room-temperature superconductors. Here, ...we identify an alternative clathrate structure in ternary Li2MgH16 with a remarkably high estimated Tc of ∼473 K at 250 GPa, which may allow us to obtain room-temperature or even higher-temperature superconductivity. The ternary compound mimics a Li- or electron-doped binary hydride of MgH16. The parent hydride contains H2 molecules and is not a good superconductor. The extra electrons introduced break up the H2 molecules, increasing the amount of atomic hydrogen compared with the parent hydride, which is necessary for stabilizing the clathrate structure or other high-Tc structures. Our results provide a viable strategy for tuning the superconductivity of hydrogen-rich hydrides by donating electrons to hydrides via metal doping. Our approach may pave the way for finding high-Tc superconductors in a variety of ternary or quaternary hydrides.
We have developed a software package CALYPSO (Crystal structure AnaLYsis by Particle Swarm Optimization) to predict the energetically stable/metastable crystal structures of materials at given ...chemical compositions and external conditions (e.g., pressure). The CALYPSO method is based on several major techniques (e.g. particle-swarm optimization algorithm, symmetry constraints on structural generation, bond characterization matrix on elimination of similar structures, partial random structures per generation on enhancing structural diversity, and penalty function, etc.) for global structural minimization from scratch. All of these techniques have been demonstrated to be critical to the prediction of global stable structure. We have implemented these techniques into the CALYPSO code. Testing of the code on many known and unknown systems shows high efficiency and the highly successful rate of this CALYPSO method Y. Wang, J. Lv, L. Zhu, Y. Ma, Phys. Rev. B 82 (2010) 094116 29. In this paper, we focus on descriptions of the implementation of CALYPSO code and why it works.
Pollution caused by nondegradable plastics has been a serious threat to environmental sustainability. Natural polymers, which can degrade in nature, provide opportunities to replace petroleum‐based ...polymers, meanwhile driving technological advances and sustainable practices. In the research field of soft electronics, regenerated natural polymers are promising building blocks for passive dielectric substrates, active dielectric layers, and matrices in soft conductors. Here, the natural‐polymer polymorphs and their compatibilization with a variety of inorganic/organic conductors through interfacial bonding/intermixing and surface functionalization for applications in various device modalities are delineated. Challenges that impede the broad utilization of natural polymers in soft electronics, including limited durability, compromises between conductivity and deformability, and limited exploration in controllable degradation, etc. are explicitly inspected, while the potential solutions along with future prospects are also proposed. Finally, integrative considerations on material properties, device functionalities, and environmental impact are addressed to warrant natural polymers as credible alternatives to synthetic ones, and provide viable options for sustainable soft electronics.
Produced and modified by living organisms, natural polymers are credible alternatives to synthetic polymers ascribing to their biodegradability, biocompatibility, and capability in interfacing with cutting‐edge technologies. The adoption of natural polymers in soft electronic devices is discussed, and the key challenges in polymer‐to‐conductor integration, device stability, biodegradation, and their environmental impact are addressed.
Despite the fast development of various energy harvesting and storage devices, their judicious integration into efficient, autonomous, and sustainable wearable systems has not been widely explored. ...Here, we introduce the concept and design principles of e-textile microgrids by demonstrating a multi-module bioenergy microgrid system. Unlike earlier hybrid wearable systems, the presented e-textile microgrid relies solely on human activity to work synergistically, harvesting biochemical and biomechanical energy using sweat-based biofuel cells and triboelectric generators, and regulating the harvested energy via supercapacitors for high-power output. Through energy budgeting, the e-textile system can efficiently power liquid crystal displays continuously or a sweat sensor-electrochromic display system in pulsed sessions, with half the booting time and triple the runtime in a 10-min exercise session. Implementing "compatible form factors, commensurate performance, and complementary functionality" design principles, the flexible, textile-based bioenergy microgrid offers attractive prospects for the design and operation of efficient, sustainable, and autonomous wearable systems.
Universality is a pillar of modern critical phenomena. The standard scenario is that the two-point correlation algebraically decreases with the distance r as g(r) ~ r2-d−η, with d the spatial ...dimension and η the anomalous dimension. Very recently, a logarithmic universality was proposed to describe the extraordinary surface transition of the O(N) system. In this logarithmic universality, g(r) decays in a power of logarithmic distance as g(r) ∼ (lnr)−η, dramatically different from the standard scenario. We explore the three-dimensional XY model by Monte Carlo simulations, and provide strong evidence for the emergence of logarithmic universality. Moreover, we propose that the finite-size scaling of g(r, L) has a two-distance behavior: simultaneously containing a large-distance plateau whose height decays logarithmically with L as g(L) ~ (lnL)-η′ as well as the r-dependent term g(r) ∼ (lnr)−η, with ^ η ′ ≈ η-. The critical exponent η, characterizing the height of the plateau, obeys the scaling relation η′ = (N-1)/(2πα) with the RG parameter α of helicity modulus. Our picture can also explain the recent numerical results of a Heisenberg system. The advances on logarithmic universality significantly expand our understanding of critical universality.
Electrically activated soft actuators with large deformability are important for soft robotics but enhancing durability and efficiency of electrochemical actuators is challenging. Herein, we ...demonstrate that the actuation performance of an ionic two-dimensional covalent-organic framework based electrochemical actuator is improved through the ordered pore structure of opening up efficient ion transport routes. Specifically, the actuator shows a large peak to peak displacement (9.3 mm, ±0.5 V, 1 Hz), a fast-response time to reach equilibrium-bending (~1 s), a correspondingly high bending strain difference (0.38%), a broad response frequency (0.1-20 Hz) and excellent durability (>99%) after 23,000 cycles. The present study ascertains the functionality of soft electrolyte as bionic artificial actuators while providing ideas for expanding the limits in applications for robots.
Background and Aim
Remimazolam tosilate (RT) is a new short‐acting GABA(A) receptor agonist, having potential to be an effective option for procedural sedation. Here, we aimed to compare the efficacy ...and safety of RT with propofol in patients undergoing upper gastrointestinal endoscopy.
Methods
This positive‐controlled, non‐inferiority, phase III trial recruited patients at 17 centers, between September 2017 and November 2017. A total of 384 patients scheduled to undergo upper gastrointestinal endoscopy were randomly assigned to receive RT or propofol. Primary endpoint was the success rate of sedation. Adverse events (AEs) were recorded to evaluate safety.
Results
The success rate of sedation in the RT group was non‐inferior to that in the propofol group (97.34% vs 100.00%; difference in rate −2.66%, 95% CI −4.96 to −0.36, meeting criteria for non‐inferiority). Patients in the RT group had longer time to adequate sedation (P < 0.0001) but shorter time to fully alert (P < 0.0001) than that in the propofol group. The incidences of hypotension (13.04% vs 42.86%, P < 0.0001), treatment‐related hypotension (0.54% vs 5.82%, P < 0.0001), and respiratory depression (1.09% vs 6.88%, P = 0.0064) were significantly lower in the RT group. AEs were reported in 74 (39.15%) patients in the RT group and 114 (60.32%) patients in the propofol group, with significant difference (P < 0.0001).
Conclusion
This trial established non‐inferior sedation success rate of RT compared with propofol. RT allows faster recovery from sedation compared with propofol. The safety profile is favorable and appears to be superior to propofol, indicating that it was feasible and well tolerated for patients.
Hydrochar produced from agricultural and forestry wastes and its application into the environment are very attractive. Herein, a high-efficiency dithiocarbamate-modified hydrochar (DTHC) was prepared ...successfully and then applied to eliminate Pb(II) from aqueous solutions. DTHC was characterized by various techniques. It was found that dithiocarbamate and amine groups were successfully grafted onto the surface of hydrochar. The surface area of DTHC was 7.94 m2·g−1, which was four folds less than pristine hydrochar (31.60 m2·g−1), but its adsorption capacity obviously increased. Adsorption experiments showed that the Pb(II) adsorption process onto DTHC well accorded with pseudo-2nd-order kinetics and Langmuir isotherms. The highest Pb(II) uptake by DTHC at 293 K determined from the Langmuir model was 151.51 mg·g−1. Fourier transform infrared spectra and X-ray photoelectron spectroscopy verified that dithiocarbamate, carboxylate, amine and sulfonate groups all facilitated the Pb(II) adsorption. The adsorption mechanism was ascribed to the inner-sphere surface complexation of Pb(II) by these groups and to the ion exchange between Pb(II) and Na(I). Thus, DTHC is an effective adsorbent for Pb(II) removal from water.
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•Dithiocarbamate functionalized hydrochar was synthesized as an adsorbent.•The adsorbent showed high adsorption performance toward for Pb(II).•Surface complexation is the main adsorption mechanism to be elucidated.•A variety of functional groups are involved in surface complexation verified by FTIR and XPS.
•ACHC with abundant amino, hydroxyl and carboxylate groups was prepared successfully.•ACHC can remove efficiently and rapidly MB and Cu(II) from aqueous solution.•The surface chelation was mainly ...contribute to Cu(II) adsorption.•π-π interaction, hydrogen bond and electrostatic attraction dominated MB adsorption.
The polyaminocarboxylated modified hydrochar (ACHC) was synthesized to introduce abundant amino, hydroxyl and carboxylate multifunctional groups onto the surface of hydrochar by etherification, amination and carboxylated reaction. The ACHC was systematically characterized and used to evaluate adsorption properties of Cu(II) and methylene blue (MB) by batch sorption tests. The adsorption process toward Cu(II) and MB by ACHC obeyed the pseudo-second-order kinetic model and Langmuir model. Characteristic analysis indicated the surface chelation was mainly contribute to Cu(II) adsorption by large amounts of amino and carboxylate groups while π-π interaction, hydrogen bonding and electrostatic attraction dominated MB adsorption. The maximum adsorption capacities of ACHC were 140.65 and 1238.66 mg·g−1 for Cu(II) and MB at 303 K, respectively. Approximately 97% of the adsorptive uptakes for two pollutants were removed within merely 5 min for kinetic experiment. Competitive adsorption of Cu(II) and MB, and treatment of electroplating wastewater by ACHC were also investigated.
•Co-HTC of PVC and bamboo was employed to prepare high-efficiency adsorbent.•The contents of hydroxyl and carboxyl groups of hydrochar increased during Co-HTC.•Adsorption capacity of MB on hydrochar ...produced by addition of PVC increased significantly.•Electrostatic and hydrogen-bonding interactions are the main mechanisms.
Polyvinyl chloride (PVC) was blended into bamboo powder during co-hydrothermal carbonization (Co-HTC) to understand the effects on the physicochemical properties and adsorbing ability of hydrochar. The properties of hydrochar were characterized by Zeta potential, elemental analyses, BET, FTIR, XPS, Boehm titration and SEM. The addition of PVC into bamboo in Co-HTC decreased the BET area, and pore volume and radius of hydrochar, but increased the contents of surface hydroxyl and carboxyl groups. The adsorption ability of hydrochar produced by addition of PVC at 473 K over methylene blue (MB) increased significantly. The main adsorption mechanism was electrostatic attraction by –N(CH3)2+ of MB and carboxylate of hydrochar, and hydrogen-bonding interaction through N atom of phenothiazine in MB and C–OH of hydrochar. Thus, Co-HTC offers a facile, green and economical alternative for conversion of waste into high-value adsorbents.
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