Alleviating large stress is critical for high‐energy batteries with large volume change upon cycling, yet this still presents a challenge. Here, a gradient hydrogen‐bonding binder is reported for ...high‐capacity silicon‐based anodes that are highly desirable for the next‐generation lithium‐ion batteries. The well‐defined gradient hydrogen bonds, with a successive bond energy of −2.88– −10.04 kcal mol−1, can effectively release the large stress of silicon via the sequential bonding cleavage. This can avoid recurrently abrupt structure fracture of traditional binder due to lack of gradient energy dissipation. Certainly, this regulated binder endows stable high‐areal‐capacity silicon‐based electrodes >4 mAh cm−2. Beyond proof of concept, this work demonstrates a 2 Ah silicon‐based pouch cell with an impressive capacity retention of 80.2% after 700 cycles (0.028% decay/cycle) based on this gradient hydrogen‐bonding binder, making it more promising for practical application.
A gradient H‐bonding polymer binder for Si‐based anodes is reported, where the H‐bond energies are regulated in a wide range. The well‐defined gradient hydrogen bonds can effectively release stress and maintain the integrity of the electrode via sequential bonding cleavage. Additionally, a 2 Ah pouch cell with an impressive capacity retention makes this binder more promising for practical application.
We describe a unique averaging procedure to design an entropy stable dissipation operator for the ideal magnetohydrodynamic (MHD) and compressible Euler equations. Often in the derivation of an ...entropy conservative numerical flux function much care is taken in the design and averaging of the entropy conservative numerical flux. We demonstrate in this work that if the discrete dissipation operator is not carefully chosen as well it can have deleterious effects on the numerical approximation. This is particularly true for very strong shocks or high Mach number flows present, for example, in astrophysical simulations. We present the underlying technique of how to construct a unique averaging technique for the discrete dissipation operator. We also demonstrate numerically the increased robustness of the approximation.
To reveal fracture mechanism of gas-bearing coal subjected to complex geology environment, the impact dynamics experiments were conducted to study energy characteristics based on split Hopkinson ...pressure bar (SHPB) system. The incident, reflected and transmission strain were collected to calculate various energy. It was found reflected strain was always larger than transmission strain. Therefore, the reflected energy was generally higher than transmission energy under different loading conditions, but they were smaller than incident energy. With time evolution, both elastic deformation and dissipative energy experienced slow increase, rapid increase, peak point and decrease stage regardless of loading conditions. Before macro failure, micro-meso fractures had changed drasticly, which also involved intense energy conversion. So dissipative energy peak was earlier than that of elastic deformation energy. Due to pre-damage of static load and weakening effects of gas, the dissipative energy decreased with their increases (static load from 2.00 to 9.00 MPa and gas pressure from 0.25 to 1.50 MPa) during impact fracture process. However, at high confining pressure and dynamic load environment, the impact failure of gas-bearing coal exhausted massive energy. These energy characteristics will provide guidances to prevent and control disaster during coal mining and coal seam gas (CSG) exploitation in deep area.
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•Instant strain characteristics of gas-bearing coal were analyzed under dynamic load.•Energy dissipation mechanism of gas-bearing coal were revealed during impact process.•The effects of loading conditions to energy evolution of gas-bearing coal were discussed.
The baffle drop shaft is widely used in deep tunnel drainage systems due to its fine applicability and high energy dissipation. To fully study the turbulence characteristics and energy dissipation ...mechanism of baffle drop shafts, a 1:25 scale physical model test and a numerical simulation based on the Realizable k-ε model and Volume of Fluid (VOF) method were performed. The results showed that a baffle spacing that is too dense or too sparse is not conducive to energy dissipation and discharge. The minimum baffle spacing is the optimal structural design at the design flow rate when the flow regime is free-drop flow. The energy dissipation calculation model established in this paper has high accuracy for calculating the energy dissipation rate on the baffles in free-drop flow. The energy dissipation modes of the shaft can be divided into inlet energy dissipation, baffle energy dissipation, and shaft-bottom energy dissipation. Baffles play a major role in the energy dissipation at low flow rates, and the proportions of inlet and shaft-bottom energy dissipation increase with the increase in flow rate.
The large bank of data for ceramics from experiments in flash sintering reveal a surprising characteristic: that the transition to a highly nonlinear rise in electrical conductivity—a signature event ...for the onset of the flash—occurs within a narrow range of power density. This condition holds for ceramics that are semiconductors, ionic conductors, electronic conductors, and insulators.They flash at temperatures that range from 300°C to 1300°C, and at electric fields from 10 V/cm to over 1000 V/cm. Yet, the power expenditure at the transition for all of them still falls within this narrow range. This, rather uniform value of power dissipation suggests that Joule heating is a key factor in instigating the flash. A general formulation is developed to test if indeed Joule heating alone can lead to the progression of such nonlinear behavior. It is concluded that Joule heating is a necessary but not a sufficient condition for flash sintering.
Engineered dissipation can be used for quantum state preparation. This is achieved with a suitably engineered coupling to a dissipative cold reservoir usually formed by an electromagnetic mode. In ...the field of cavity electro- and optomechanics, the electromagnetic cavity naturally serves as a cold reservoir for the mechanical mode. Here, we realize the opposite scenario and engineer a mechanical oscillator cooled close to its ground state into a cold dissipative reservoir for microwave photons in a superconducting circuit. By tuning the coupling to this dissipative mechanical reservoir, we demonstrate dynamical backaction control of the microwave field, leading to stimulated emission and maser action. Moreover, the reservoir can function as a useful quantum resource, allowing the implementation of a near-quantum-limited phase-preserving microwave amplifier. Such engineered mechanical dissipation extends the toolbox of quantum manipulation techniques of the microwave field and constitutes a new ingredient for optomechanical protocols.
We reveal the cooperative effect of coherent and dissipative magnon-photon couplings in an open cavity magnonic system, which leads to nonreciprocity with a considerably large isolation ratio and ...flexible controllability. Furthermore, we discover unidirectional invisibility for microwave propagation, which appears at the zero-damping condition for hybrid magnon-photon modes. A simple model is developed to capture the generic physics of the interference between coherent and dissipative couplings, which accurately reproduces the observations over a broad range of parameters. This general scheme could inspire methods to achieve nonreciprocity in other systems.
•Unsteady three dimensional flow of ferro-nanoliquid under vibrational rotations is formulated.•Homogeneous/heterogeneous reactions and non-linear radiation effects are incorporated.•Effects of slip ...at liquid-sheet interface and viscous/Ohmic dissipations are examined.•Vibrational rotations and slip conditions substantially regulate the flow field.
We investigated the role of vibrational rotations and slip conditions at liquid-sheet interface in maintaining the three dimensional flow of ferro-nanoliquid (water-Fe3O4) over a bi-directionally stretchable surface under the influence of magnetic field. It is assumed that chemical reactions prevail between two species A and B whose diffusion coefficients are unequal. Also, mass transfer is considered in the presence of homogeneous and heterogeneous reactions for species A and B. Influences of nonlinear thermal radiation along with viscous dissipation and Joule heating are also invoked into the analysis due to their predominance in the control of heat and mass transfer mechanism. Stability and convergence limitations are verified to ensure the accuracy of results. The outcome due to proposed explicit finite difference scheme is exhibited in the form of figures and tables to illustrate the influence of emerging parameters for two cases namely slip nanofluid (SNF) and no slip nanofluid (NSNF). Results reveal that vibrational rotations and slip at the surface of sheet substantially control flow, and heat and mass transfer phenomena.
QCM-D study of nanoparticle interactions Chen, Qian; Xu, Shengming; Liu, Qingxia ...
Advances in colloid and interface science,
July 2016, 2016-Jul, 2016-07-00, 20160701, Letnik:
233
Journal Article
Recenzirano
Odprti dostop
Quartz crystal microbalance with dissipation monitoring (QCM-D) has been proven to be a powerful research tool to investigate in situ interactions between nanoparticles and different functionalized ...surfaces in liquids. QCM-D can also be used to quantitatively determine adsorption kinetics of polymers, DNA and proteins from solutions on various substrate surfaces while providing insights into conformations of adsorbed molecules. This review aims to provide a comprehensive overview on various important applications of QCM-D, focusing on deposition of nanoparticles and attachment-detachment of nanoparticles on model membranes in complex fluid systems. We will first describe the working principle of QCM-D and DLVO theory pertinent to understanding nanoparticle deposition phenomena. The interactions between different nanoparticles and functionalized surfaces for different application areas are then critically reviewed. Finally, the potential applications of QCM-D in other important fields are proposed and knowledge gaps are identified.
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•Described principle of QCM-D and the classical and extended DLVO theory•Reviewed current state on studies of nanoparticle interactions in different aqueous systems by QCM-D•Summarized decisive factors affecting nanoparticle deposition and detachment in aqueous systems•Proposed advantages–disadvantages and potential application fields of QCM-D
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