Uncovering the principle of neural coding is essential for understanding how our mysterious brain works. Recent studies have reported the laminar differences of alpha-beta and gamma rhythms in the sensory cortex, yet it remains unclear about the underlying function role of frequency-dependent interlaminar interactions in neural coding. Using a rate-based network model to simulate the cortical laminar under the external time-varying stimuli, we showed that the physiological specificity of rhythms for layers enables the cortical laminae to preferentially encode information in different frequency ranges. The interplay of the supragranular layer and infragranular layer contributes significantly to improving the neural representation of external time-varying input at the population level. Further investigations revealed the essential role of recurrent connections of the cortical laminae in regulating the population rate coding. In particular, the laminar network optimally encodes the time-varying input at intermediate strengths of intralaminar excitatory–inhibitory circuits and interlaminar connections. Additionally, we verified the crucial role of adaptation in improving population coding by introducing slow dynamics and suppressing the noise-like excitatory activity in the laminar network. These findings highlight the crucial role of frequency-dependent interlaminar interactions in encoding time-varying stimuli and may shed light on the underlying function of cortical structural specificity in neural information processing.
Room-temperature sodium–sulfur (RT−Na/S) batteries hold great promise to meet the requirements of large-scale energy storage due to their high theoretical energy density, low material cost, resource abundance, and environmental benignity. However, the poor cycle performance and low utilization of active sulfur greatly hinder their practical application. As the essential part directly related to the battery performance, the S-based cathode has attracted tremendous research interests in recent years. This review highlights recent progress in cathode materials for RT−Na/S batteries. Particularly, basic insights into the Na/S reaction mechanism are presented and representative works on S-based cathode materials are systematically summarized. The remaining challenges and developing trends of RT−Na/S batteries are also discussed. We hope this review can shed light on the field of next-generation metal-sulfur batteries. 相似文献
A W/O microemulsion was prepared with Span80-PS (petroleum sulfonate) as complex emulsifier, isopropanol as cosurfactant and
kerosene as oil phase. The optimal constituents of microemulsion were found from pseudoternary phase diagrams: the mass ratio
of Span80 to PS was 4:1 and complex surfactant to cosurfactant was 1:1. The Fe3O4 magnetic fluid was obtained by one-step method with the W/O microemulsion as microreactor to synthesize magnetic nanoparticles
(reaction temperature was 30 °C and reaction time was 5 h) and kerosene as carrier liquid. The magnetic fluid was investigated
by TEM, XRD and fluorescence microscope. The magnetism was determined by Gouy magnetic balance. The average particle size
of Fe3O4 was 7.4 nm, and magnetic particles were well-dispersed. The stable Fe3O4 magnetic fluid with good magnetism may be produced by one-step method in the W/O microemulsion. Accordingly, the traditional
preparation method of magnetic fluid can be simplified greatly.
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Translated from Chinese Journal of Applied Chemistry, 2005, 22 (7) (in Chinese) 相似文献
In this paper, we study the curve shortening flow in a general Riemannian manifold. We have many results for the global behavior
of the flow. In particular, we show the following results: let M be a compact Riemannian manifold. (1) If the curve shortening flow exists for infinite time, and
, then for every n > 0,
. Furthermore, the limiting curve exists and is a closed geodesic in M. (2) In M × S1, if γ0 is a ramp, then we have a global flow which converges to a closed geodesic in C∞ norm. As an application, we prove the theorem of Lyusternik and Fet.
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Based on the combination of colloidal‐crystal templating and a molecular imprinting technique, a sensor platform for efficient detection of atrazine in aqueous solution has been developed. The sensor is characterized by a 3D‐ordered interconnected macroporous structure in which numerous nanocavities derived from atrazine imprinting are distributed in the thin wall of the formed inverse polymer opal. Owing to the special hierarchical porous structure, the molecularly imprinted polymer opals (or molecularly imprinted photonic polymer; MIPP) allow rapid and ultrasensitive detection of the target analyte. The interconnected macropores are favorable for the rapid transport of atrazine in polymer films, whereas the inherent high affinity of nanocavites distributed in thin polymer walls allows MIPP to recognize atrazine with high specificity. More importantly, the atrazine recognition events of the created nanocavities can be directly transferred (label‐free) into a readable optical signal through a change in Bragg diffraction of the ordered macropores array of MIPP and thereby induce color changes that can be detected by the naked eye. With this novel sensory system, direct, ultrasensitive (as low as 10?8 ng mL?1), rapid (less than 30 s) and selective detection of atrazine with a broad concentration range varying from 10?16 M to 10?6 M in aqueous media is achieved without the use of label techniques and expensive instruments. 相似文献