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131.
Advanced High‐Voltage Aqueous Lithium‐Ion Battery Enabled by “Water‐in‐Bisalt” Electrolyte
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Dr. Liumin Suo Dr. Oleg Borodin Wei Sun Dr. Xiulin Fan Dr. Chongyin Yang Dr. Fei Wang Tao Gao Dr. Zhaohui Ma Dr. Marshall Schroeder Dr. Arthur von Cresce Dr. Selena M. Russell Prof. Michel Armand Prof. Austen Angell Dr. Kang Xu Prof. Chunsheng Wang 《Angewandte Chemie (International ed. in English)》2016,55(25):7136-7141
A new super‐concentrated aqueous electrolyte is proposed by introducing a second lithium salt. The resultant ultra‐high concentration of 28 m led to more effective formation of a protective interphase on the anode along with further suppression of water activities at both anode and cathode surfaces. The improved electrochemical stability allows the use of TiO2 as the anode material, and a 2.5 V aqueous Li‐ion cell based on LiMn2O4 and carbon‐coated TiO2 delivered the unprecedented energy density of 100 Wh kg?1 for rechargeable aqueous Li‐ion cells, along with excellent cycling stability and high coulombic efficiency. It has been demonstrated that the introduction of a second salts into the “water‐in‐salt” electrolyte further pushed the energy densities of aqueous Li‐ion cells closer to those of the state‐of‐the‐art Li‐ion batteries. 相似文献
132.
We present a primal–dual algorithm for solving a constrained optimization problem. This method is based on a Newtonian method applied to a sequence of perturbed KKT systems. These systems follow from a reformulation of the initial problem under the form of a sequence of penalized problems, by introducing an augmented Lagrangian for handling the equality constraints and a log-barrier penalty for the inequalities. We detail the updating rules for monitoring the different parameters (Lagrange multiplier estimate, quadratic penalty and log-barrier parameter), in order to get strong global convergence properties. We show that one advantage of this approach is that it introduces a natural regularization of the linear system to solve at each iteration, for the solution of a problem with a rank deficient Jacobian of constraints. The numerical experiments show the good practical performances of the proposed method especially for degenerate problems. 相似文献
133.
Armand Cholewka Agata Stanek Magdalena Wójcik Karolina Sieroń-Stołtny Zofia Drzazga 《Journal of Thermal Analysis and Calorimetry》2017,127(2):1155-1162
Thermal imaging has been used for patients with spinal diseases who were qualified by their physicians for whole-body treatment or local cryotherapy. The experimental groups of patients consisted of 20 males aged 51.6 ± 9.0 (12 treated by whole-body cryotherapy and 8 by local cryotherapy). The distribution of the skin surface temperature was monitored by using a Thermovision Camera E60 before and immediately after body cooling. The chosen spinal region (Th5/Th6–L5/S1) was taken into consideration for all of the research groups. An essential drop in skin temperature and a better differentiation of the body surface temperatures (leading to an increase in the diagnostic value of thermography) was observed after both methods of cold impact. In order to estimate the usefulness of thermovision used after body cooling, the quantitative parameters including temperature contrast—the difference between the maximum and minimum temperatures before and after cold impact and relative contrast ratio (related to the average temperature of the selected area of interest, before and after cooling, respectively)—were compared for both kinds of medical treatment. The statistical analysis proved that significant differences between the parameters obtained before and after body cooling in the case that patients treated by local and whole-body cryotherapy are similar. However, local therapy is cheaper and easy for application while whole-body therapy can give more information about the state of soft tissues for the whole back. 相似文献
134.
135.
Motivated by its importance for microfluidic applications, we study the stability of jets formed by pressure-driven concentric biphasic flows in cylindrical capillaries. The specificity of this variant of the classical Rayleigh-Plateau instability is the role of the geometry which imposes confinement and Poiseuille flow profiles. We experimentally evidence a transition between situations where the flow takes the form of a jet and regimes where drops are produced. We describe this as the transition from convective to absolute instability, within a simple linear analysis using lubrication theory for flows at low Reynolds number, and reach remarkable agreement with the data. 相似文献
136.
Lu Yin Li Han Feijie Ge Xia Tong Wei Zhang Armand Soldera Yue Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):15241-15246
Liquid crystalline elastomers (LCEs) have been actively investigated as stimuli-controlled actuators and soft robots. The basis of these applications is the ability of LCEs to undergo a reversible shape change upon a liquid crystalline (LC)-isotropic phase transition. Herein, we report the synthesis of a novel LCE based on a side-chain liquid crystalline polymer (SCLCP). In contrast to known LCEs, this LCE exhibits a striking anomalous shape change. Subjecting a mechanically stretched monodomain strip to LC-disorder phase transition, both the length and width of the strip contract in isotropic phase, and both elongate in LC phase. This thermally induced behaviour is the result of a subtle interplay between the relaxation of polymer main chain oriented along the stretching direction and the disordering of side-group mesogens oriented perpendicularly to the stretching direction. This finding points out potential design of LCEs of this peculiar type and possible applications to exploit. 相似文献
137.
The three-state test (3ST) is a method based on ordinal pattern analysis for detecting chaos and determining the period in time series. For some well-known chaotic dynamical systems, we showed that the test behaves similar to Lyapunov exponents. However, the 3ST is detecting quasi-periodic motions both as regular and non-regular. In this paper, we propose to use the sensitivity of its chaos indicator \(\lambda \) on time delay for clear discernment between quasi-periodic and chaotic dynamics. Simulation results obtained using the logistic map and the sine-circle map attest that the sensitivity of \(\lambda \) on time delay is sufficient for the detection of the periodic and quasi-periodic route to chaos. A comparison with the permutation entropy confirms the effectiveness of the 3ST for the analysis of discrete time series data. 相似文献
138.
Christoph Wlper Naveed Anwar Naeem Gulzar Peter G. Jones Armand Blaschette 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(7):o249-o254
The title compound, C6H15N2+·C2H6NO4S2−, crystallizes as a 0.11‐hydrate, (I), in the space group C2; the asymmetric unit consists of two cations (one of each enantiomer), one anion on a general position, two half anions, each with the N atom on a twofold axis, and approximately one fifth of a water molecule. The general anion departs significantly from the usual conformation: it lacks one of the typical `W'‐shaped sequence of O—S—N—S—O atoms. The compound also crystallizes in the solvent‐free form, (II), in the space group P21/c, with one formula unit in the asymmetric unit. Both compounds form ribbons of hydrogen‐bonded cation dimers parallel to the b axis. In (I), there are two independent ribbons of opposite chirality, each involving one anion on a special position, and these ribbons are connected by hydrogen bonds to the anion on a general position, resulting in a layer structure parallel to (100). In (II), the chains are connected by hydrogen bonds, and again a layer structure parallel to (100) results. 相似文献
139.
Leszczyński PJ Budzianowski A Dobrzycki L Cyrański MK Derzsi M Grochala W 《Dalton transactions (Cambridge, England : 2003)》2012,41(2):396-402
High purity samples of a [Ag(pyrazine)(2)]S(2)O(8) complex were obtained using modified synthetic pathways. Di(pyrazine)silver(II) peroxydisulfate is sensitive to moisture forming [Ag(pyrazine)(2)](S(2)O(8))(H(2)O) hydrate which degrades over time yielding HSO(4)(-) derivatives and releasing oxygen. One polymorphic form of pyrazinium hydrogensulfate, β-(pyrazineH(+))(HSO(4)(-)), is found among the products of chemical decomposition together with unique [Ag(i)(pyrazine)](5)(H(2)O)(2)(HSO(4))(2)[H(SO(4))(2)]. Chemical degradation of [Ag(pyrazine)(2)]S(2)O(8) in the presence of trace amounts of moisture can explain the very low yield of wet synthesis (11-15%). Attempts have failed to obtain a mixed valence Ag(II)/Ag(I) pyrazine complex via partial chemical reduction of the [Ag(pyrazine)(2)]S(2)O(8) precursor with a variety of inorganic and organic reducing agents, or via controlled thermal decomposition. Thermal degradation of [Ag(pyrazine)(2)]S(2)O(8) containing occluded water proceeds at T > 90 °C via evolution of O(2); simultaneous release of pyrazine and SO(3) is observed during the next stages of thermal decomposition (120-285 °C), while Ag(2)SO(4) and Ag are obtained upon heating to 400-450 °C. 相似文献
140.
Grochala W Cyrański MK Derzsi M Michałowski T Malinowski PJ Mazej Z Kurzydłowski D Koźmiński W Budzianowski A Leszczyński PJ 《Dalton transactions (Cambridge, England : 2003)》2012,41(7):2034-2047
Trifluoromethansulfonate of silver(I), AgSO(3)CF(3) (abbreviated AgOTf), extensively used in organic chemistry, and its fluorosulfate homologue, AgSO(3)F, have been structurally characterized for the first time. The crystal structures of both homologues differ substantially from each other. AgOTf crystallizes in a hexagonal system (R3 space group, No.148) with a = b = 5.312(3) ? and c = 32.66(2) ?, while AgSO(3)F crystallizes in a monoclinic system in the centrosymmetric P2(1)/m space group (No.11) with a = 5.4128(10) ?, b = 8.1739(14) ?, c = 7.5436(17) ?, and β = 94.599(18)°, adopting a unique structure type (100 K data). There are two types of fluorosulfate anions in the structure; in one type the F atom is engaged in chemical bonding to Ag(I) and in the other type the F atom is terminal; accordingly, two resonances are seen in the (19)F NMR spectrum of AgSO(3)F. Theoretical analysis of the electronic band structure and electronic density of states, as well as assignment of the mid- and far-infrared absorption and Raman scattering spectra for both compounds, have been performed based on the periodic DFT calculations. AgSO(3)F exhibits an unusually low melting temperature of 156 °C and anomalously low value of melting heat (ca. 1 kJ mol(-1)), which we associate with (i) disorder of its anionic sublattice and (ii) the presence of 2D sheets in the crystal structure, which are weakly bonded with each other via long Ag-O(F) contacts. AgSO(3)F decomposes thermally above 250 °C, yielding mostly Ag(2)SO(4) and liberating SO(2)F(2). AgOTf is much more thermally stable than AgSO(3)F; it undergoes two consecutive crystallographic phase transitions at 284 °C and 326 °C followed by melting at 383 °C; its thermal decomposition commences above 400 °C leading at 500 °C to crystalline Ag(2)SO(4) and an unidentified phase as major products of decomposition in the solid state. 相似文献