Electronic structure and spin state regulation of vanadium nitride via a sulfur doping strategy toward flexible zinc-air batteries

Owing to the distinctive structural characteristics,vanadium nitride(VN)is highly regarded as a catalyst for oxygen reduction reaction(ORR)in zinc-air batteries(ZABs).However,VN exhibits limited intrinsic ORR activity due to the weak adsorption ability to O-containing species.Here,the S-doped VN anchored on N,S-doped multi-dimensional carbon(S-VN/Co/NS-MC)was constructed using the solvothermal and in-situ doping methods.Incorporating sulfur atoms into VN species alters the electron spin state of vanadium in the S-VN/Co/NS-MC for regulating the adsorption energy of vanadium sites to oxygen molecules.The introduced sulfur atoms polarize the V 3d_(z)^(2) electrons,shifting spin-down electrons closer to the Fermi level in the S-VN/Co/NS-MC.Consequently,the introduction of sulfur atoms into VN species enhances the adsorption energy of vanadium sites for oxygen molecules.The*OOH dissociation transitions from being unspontaneous on the VN surface to a spontaneous state on the S-doped VN surface.Then,the ORR barrier on the S-VN/Co/NS-MC surface is reduced.The S-VN/Co/NS-MC demonstrates a higher half-wave potential and limiting current density compared to the VN/Co/N-MC.The S-VN/Co/NS-MC-based liquid ZABs display a power density of 195.7 m W cm^(-2),a specific capacity of 815.7 m A h g^(-1),and a cycling stability exceeding 250 h.The S-VN/Co/NS-MC-based flexible ZABs are successfully employed to charge both a smart watch and a mobile phone.This approach holds promise for advancing the commercial utilization of VN-based catalysts in ZABs.

高管晋升激励与审计意见——基于中介效应模型的检验

逻辑上,高管晋升激励是影响公司财务报告质量乃至审计意见的重要因素,然而现有文献研究较少。本文利用经典的中介效应模型研究发现:(1)高管晋升激励会降低非标准审计意见出现的概率;(2)在影响路径方面,公司业绩发挥着部分中介效应,盈余管理的中介效应没有得到证据支持。进一步分析发现,高管晋升激励和非标准审计意见的负相关关系主要存在于内部晋升型公司样本以及晋升概率高的公司样本中。在控制竞争性解释——高管权力影响审计意见的可能性后,本文结论仍然得到支持。文中还通过反事实推断和倾向得分匹配等方法进行稳健性分析,通过考虑反向因果关系等,进一步确保了实证结果的可靠性。

Pattern transition and regulation in a subthalamopallidal network under electromagnetic effect

Although the significant roles of magnetic induction and electromagnetic radiation in the neural system have been widely studied,their influence on Parkinson’s disease(PD)has yet to be well explored.By virtue of the magnetic flux variable,this paper studies the transition of firing patterns induced by magnetic induction and the regulation effect of external magnetic radiation on the firing activities of the subthalamopallidal network in basal ganglia.We find:(i)The network reproduces five typical waveforms corresponding to the severity of symptoms:weak cluster,episodic,continuous cluster,episodic,and continuous wave.(ii)Magnetic induction is a double-edged sword for the treatment of PD.Although the increase of magnetic coefficient may lead the physiological firing activity to transfer to pathological firing activity,it also can regulate the pathological intensity firing activity with excessiveβ-band power transferring to the physiological firing pattern with weakβ-band power.(iii)External magnetic radiation could inhibit continuous tremulous firing andβ-band power of subthalamic nucleus(STN),which means the severity of symptoms weakened.Especially,the bi-parameter plane of the regulation region shows that a short pulse period of magnetic radiation and a medium level of pulse percentage can well regulate pathological oscillation.This work helps to understand the firing activity of the subthalamopallidal network under electromagnetic effect.It may also provide insights into the mechanisms behind the electromagnetic therapy of PD-related firing activity.

Guidance-机器人视觉传感平台

视觉传感器作为智能机器人的关键技术,可以实现机器人定位、导航和目标跟踪。但是,当前市场上缺乏高性能的机器人视觉传感器平台。本文将介绍一个功能强、效率高的视觉传感平台Guidance,其包含一个中央处理器和多个(五个以上)伺服传感单元,内置的基础功能有:视觉定位、避障、景深图像生成。此外,Guidance配套有完整的SDK文档,可供使用者灵活使用并开发相关的项目,譬如自主导航、目标跟踪、定位和地图构建等。

Dispatching Fuel-cell Hybrid Electric Vehicles Toward Transportation and Energy Systems Integration

With the increasing integration of traditional elec-tric vehicles(EVs),the ensuing congestion and overloading issues have threatened the reliability of power grid operations.Hydrogen has been advocated as a promising energy carrier to achieve low-carbon transportation and energy(trans-energy)systems,which can support the popularization of fuel-cell hybrid EVs(FCHEVs)while enhancing the flexibility of power grids.In this paper,we propose an optimal scheduling framework for trans-energy systems that evaluates the merits of the hydrogen supply chain from water electrolysis,compressed storage and transportation to FCHEV utilization.A detailed FCHEV model is established,and mileage is modeled as a function of the stored electricity and hydrogen mass.A stochastic programming-based scheduling model is formulated,which minimizes the total cost of unit commitment and the hydrogen supply chain.The Dijkstra algorithm is adopted to search the shortest path for hydrogen transportation.Case studies demonstrate that FCHEVs can reduce the operational costs of tran-energy systems and facilitate the accommodation of renewable energy when compared to traditional EVs.Index Terms-Fuel-cell hybrid electric vehicle,hydrogen,mileage model,shortest path search,trans-energy systems.

基于FPGA的AMC信号处理卡的设计与实现

国内外早期,探测器装置的数据传输系统普遍采用并行总线架构,如VME、PXI总线等。随着核物理实验的发展,数据的传输速度不断提高,并行总线难以提速的弊端逐渐显现,总线速度不够导致数据无法通过背板传输。本工作采用基于MicroTCA(Micro Telecom Computing Architecture)架构设计一种新型先进的数据传输AMC(Advanced Mezzanine Card)信号处理卡。该AMC信号处理卡的背板总线使用在速度提升方面有着巨大优势的高速PCIe串行总线。通过测试验证,整个传输链路传输功能正确,链路传输的光纤误码率低于7.62×10^(−15),传输速度也接近理论的极值,达到了430 MB/s。最后,该AMC信号处理卡与前端电子学进行了联测,验证了系统的正确性。

Analysis of the optimal target node to reduce seizure-like discharge in networks

Network approaches have been widely accepted to guide surgical strategy and predict outcome for epilepsy treatment.This study starts with a single oscillator to explore brain activity,using a phenomenological model capable of describing healthy and epileptic states.The ictal number of seizures decreases or remains unchanged with increasing the speed of oscillator excitability and in each seizure,there is an increasing tendency for ictal duration with respect to the speed.The underlying reason is that the strong excitability speed is conducive to reduce transition behaviors between two attractor basins.Moreover,the selection of the optimal removal node is estimated by an indicator proposed in this study.Results show that when the indicator is less than the threshold,removing the driving node is more possible to reduce seizures significantly,while the indicator exceeds the threshold,the epileptic node could be the removal one.Furthermore,the driving node is such a potential target that stimulating it is obviously effective in suppressing seizure-like activity compared to other nodes,and the propensity of seizures can be reduced 60%with the increased stimulus strength.Our results could provide new therapeutic ideas for epilepsy surgery and neuromodulation.

不同SSP-RCP情景下中国地区基于植被功能型分类的未来土地利用变化模拟

土地利用预测产品对于气候模型预测和评估未来土地利用变化的影响至关重要.但目前全球土地利用预测产品的空间分辨率仍太粗糙,难以满足区域气候模型在区域和局地尺度上的精度要求.因此,本研究旨在为中国区域提供一套基于最新SSP-RCP情景下可直接应用于区域气候变化研究的高分辨率土地利用变化预测产品.首先,基于LUH2数据集提取不同情景下中国地区不同用地类型数量的变化情况,并使用最新开发的土地利用模拟模型(FLUS)对2015~2100年期间1 km尺度下的未来土地利用变化进行模拟.在此基础上,对模拟结果按植被功能型进行重分类,并制作了不同情景下中国地区基于植被功能型分类的土地利用预测产品.该产品的空间分辨率为5 km,能更好地描述土地利用分布的细节,对于减少高分辨率区域气候模拟的不确定性将具有重要作用.

独立董事地理距离、高铁开通与财务重述

文章运用手工收集的独立董事地理信息数据,考察独立董事地理距离与公司财务重述之间的关系。研究表明,独立董事与上市公司之间的地理距离,会加大两者之间的信息不对称程度,降低独立董事的监督作用,导致公司财务重述增多。进一步研究发现,高铁开通能够有效减缓地理距离导致的信息不对称程度,减弱地理距离对公司财务重述的影响。文章从地理经济学角度分析了独立董事监督对公司会计信息质量的重要作用,为高铁开通有助于独立董事发挥监督功能提供了经验证据,扩展了地理经济学在公司财务会计领域的研究。

Characterizing the urban spatial structure using taxi trip big data and implications for urban planning

Urban spatial structure is an important feature for assessing the effects of urban planning.Quantifying an urban spatial structure cannot only help in identifying the problems with current planning but also provide a basic reference for future adjustments.Evaluation of spatial structure is a difficult task for planners and researchers and this has been usually carried out by comparing different land use structures.However,these methods cannot efficiently reflect the influence of human activities.With the wide application of big data,analyzing data on human travel behavior has increasingly been carried out to reveal the relationship between urban spatial structure and urban planning.In this study,we constructed a human-activity space network using the taxi trip big data.Clustering at different scales revealed the hierarchy and redundancy of the spatial structure for assessing the appropriateness and shortcomings of urban planning.This method was applied to a case study based on one-month taxi trip data of Dongguan City.Existing urban spatial structures at different scales were retrieved and utilized to assess the effectiveness of the master plan designed for 2000 to 2015 and 2008 to 2020,which can help identify the limitations and improvements in the spatial structure designed in these two versions of the master plan.We also evaluated the potential effect of the master plan designed for 2016 to 2035 by providing a reference for reconstructing and optimizing future urban spatial structure.The analysis demonstrated that the taxi trip data are important big data on social spatial perception,and taxi data should be used for evaluating spatial structures in future urban planning.

股东“掏空”行为对未来股权配置的影响研究——基于无控股股东的经验证据

本文基于无控股股东视角,以我国2007—2019年A股非金融业上市公司为样本,实证检验股东“掏空”行为对未来股权配置的影响。研究发现:控股股东“掏空”程度越严重的上市公司,其未来出现无控股股东情形的可能性越大;在法治环境较好、金融发展水平较高的地区,股东“掏空”行为对未来出现无控股股东的正向影响更显著。本文基于无控股股东视角,分别丰富了控股股东“掏空”、股权配置的相关文献;同时剖析了无控股股东现象出现的原因,有助于了解无控股股东公司的治理结构,为构建一个有效的治理机制提高无控股股东公司的治理水平提供新的经验证据。