摘要：Monitoring the electrophysiology activity of neurons and blood calcium signals can enable a better understanding of disease-related neural system ***,currently,in situ calcium ion monitoring tools are scarce and exhibit low integration and limited *** this letter,we propose an implantable probe with an integrated in situ Ag/AgCl reference electrode(ISA/ARE)that can monitor action potential(AP)and Ca^(2+) concentrations.

摘要：Modern medicine is increasingly interested in advanced sensors to detect and analyze biochemical *** sensors based on potentiometric methods are a promising platform for monitoring physiological ions in biological *** semi-implantable devices are mainly based on single-parameter *** semi-implantable electrodes for multiparameter sensing have more restrictions on the electrode size due to biocompatibility considerations,but reducing the electrode surface area could potentially limit electrode *** study developed a semi-implantable device system comprising a multiplexed microfilament electrode cluster(MMEC)and a printed circuit board for real-time monitoring of intra-tissue K^(+),Ca^(2+),and Na^(+)*** electrode surface area was less important for the potentiometric sensing mechanism,suggesting the feasibility of using a tiny fiber-like electrode for potentiometric *** MMEC device exhibited a broad linear response(K^(+):2–32 mmol/L;Ca^(2+):0.5–4 mmol/L;Na^(+):10–160 mmol/L),high sensitivity(about 20–45 mV/decade),temporal stability(>2weeks),and good selectivity(>80%)for the above *** vitro detection and in vivo subcutaneous and brain experiment results showed that the MMEC system exhibits good multi-ion monitoring performance in several complex *** work provides a platform for the continuous real-time monitoring of ion fluctuations in different situations and has implications for developing smart sensors to monitor human health.

摘要：将不同金属元素通过合金化形成二维材料(金属烯)对基础研究和纳米电子器件的实际应用具有重要意义,但目前鲜有金属烯材料是具有本征带隙的半导体.受离子晶体成键特征的启发,通过结构搜索、成键分析和高通量第一性原理计算,本文从2500多个双金属烯中筛选出一系列具有晶格动力学稳定和碱金属-金离子键的二维碱金属金化物双金属烯半导体.由于碱金属和金之间的大电负性差,其中32个碱金属金化物双金属烯是带隙范围为0.97~5.20 eV的半导体材料,而锂金双金属烯由于电负性差减小呈现出金属性.Bohn-Oppenheimer分子动力学模拟表明19个双金属烯在室温下结构稳定有利于实际应用.这项研究为设计双金属烯半导体提供了指导,并揭示了二维金属合金中成键行为和电子结构性质间的关联.

摘要：非质子锂氧电池基于锂金属与氧的可逆反应生成Li_(2)O_(2),可提供极高的理论能量密度.然而,Li_(2)O_(2)的成核/消除机制仍然不清楚.因此,构建能在原子水平上深入了解催化机理的催化剂体系,是开发高性能锂氧电池的关键.在此,我们报道了一种在富氧空位的Co_(3)O_(4)(Pd1-Co_(3)O_(4x))中实现Pd单原子选择性锚定的策略.原子水平表征技术揭示了Pd原子优先地结合到缺陷Co_(3)O_(4)的四面体位点.理论计算表明,选择性锚定的Pd单原子与氧空位的耦合引起了明显的电荷重分布,这可以有效地提高Pd 4d轨道在费米能级附近的能带占用率,促进电子转移,有利于中间体的吸附.这种双重相互作用不仅可以调节放电过程中Li_(2)O_(2)的成核生长过程,而且有利于Li_(2)O_(2)上的电子云的离域,减弱Li-O键的强度,从而促进Li_(2)O_(2)在充电过程中的分解.本研究对锂氧电池在原子水平上的催化机理和高效催化剂的合理设计提出了一些见解.

摘要：本工作利用基于密度泛函理论的高通量计算方法,研究了由金属团簇和四羟基苯(THB)分子形成的232个具有Kagome晶格的有机金属网格.在由THB分子和过渡金属原子三聚体(称为Y_(3)-THB)组成的有机金属网格中,有7种网格结构是本征有机拓扑绝缘体.进一步引入过渡金属原子(Tl,Pb,Bi)后得到的X_(3)Y_(4)-THB结构中,发现了9个具有较大自旋轨道耦合能隙的本征有机拓扑绝缘体.在这些本征拓扑绝缘体中,α相Pb_(3)Zn_(4)-THB结构是具有拓扑平带的拓扑绝缘体,其非平庸自旋轨道耦合能隙(97.5 meV)几乎是其平带带宽(22.5 meV)的4倍,是实现分数量子霍尔效应的理想平台.该工作为设计具有大能隙的二维有机拓扑绝缘体提供了新的途径.

摘要：电化学一氧化氮传感器能够实时监测颅内一氧化氮浓度,对于了解大脑中一氧化氮的功能至关重要.然而,在大脑中使用的传统刚性传感电极面临着灵敏度低和植入后神经炎症引起一氧化氮浓度异常的问题.在这里,我们报道了一种结合物理和化学吸附能力、具有高灵敏度和准确性的电化学一氧化氮传感器.其对一氧化氮的物理和化学吸附能力分别来自于电极的高比表面积和丰富的羧基官能团.此外,柔软的电极可以与脑组织的力学性能相匹配,实现了一个高度适应的电极/组织界面.由此设计的颅内一氧化氮传感器表现出迄今为止所报道文献中最高的灵敏度,为3245 pA nmol^(-1)L,检测限为0.1 nmol L^(-1).电极在植入后未观察到显著的炎症反应以及过量的一氧化氮表达,提高了检测的准确性.该传感器成功捕捉了大脑中的一氧化氮波动,并实现了对多个脑区的同时检测,促进了对大脑中一氧化氮生理病理作用的研究.

摘要：层状无机材料的弱层间耦合和大面积表面为构建低导热性无机固体材料提供了基本框架.合成具有足够散射和非谐波性的稳定层状材料,从而降低热导率,仍是一项挑战.本文在层状无机FeOCl材料体系中,通过一步氧化还原反应成功获得了一种结构稳定的富含Fe^(2+)的层状材料,实现了表面和界面的同步改性,并实现了超低的热导率.具体而言,系统的X射线吸收精细结构(XAFS)分析和电子能量损失光谱(EELS)分析表明,碱金属原子的层间插层和表面缺陷的引入诱导了大量Fe^(2+)的存在,从而增强了其非谐波性和声子散射.此外,声子态密度(PDOS)分布也提供了确凿的证据,证明了散射概率的提高和声子模式整体的软化.所制得的层状无机材料Fe(III)_(1−n)Fe(II)_(n)O_(1−x)Cl[K^(+)]_(m)不仅结构稳定,而且在298 K时的热导率比原始FeOCl降低了近60%,低至0.29 W m^(−1) K^(−1),这在层状无机材料中是极低的.这项研究为低导热层状材料的设计提供了新的视角.

摘要：Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks （HetNets） has been formulated. The constraints of power and re-source block allocation in the physical layer, delay and target data rate in the medium ac-cess control layer, urgent queue length in the network layer, and packet error rate in the transport layer, have been considered. The original problem is non-deterministic polyno-mial time hard, which cannot be solved practi-cally. After the restrictions of upper layers are translated into constraints with physical layer parameters, and the integer restrictions are relaxed, the original problem can be decom- posed into convex optimization subproblems. The optimal solutions of resource block allo-cation and power allocation can be obtained by using the Lagrangian optimization. Simula-tion results show that the proposed scheme is better than both the round robin algorithm and the max-rain one in terms of energy efficiency, throughput and service fairness. The round robin algorithm and the max-min one only focus on the user fairness rather than quality of service fairness. Compared to the round robin scheme （the max-min one）, the proposed scheme improves the energy efficiency 58.85% （62.41%）, the throughput 19.09% （25.25%）, the service fairness 57.69% （35.48%）.

摘要：The origin of the Rayleigh scattering ring effect has been experimentally examined on a quantum dot/metal film system, in which CdTe quantum dots embedded in PVP are spincoated on a thin Au film. On the basis of the angle-dependent, optical measurements under different excitation schemes （i.e., wavelength and polarization）, we demonstrate that surface plasmon assisted directional radiation is responsible for such an effect. Moreover, an interesting phase-shift behavior is addressed.

摘要：The traffic equilibrium assignment problem under tradable credit scheme(TCS) in a bi-modal stochastic transportation network is investigated in this paper. To describe traveler’s risk-taking behaviors under uncertainty, the cumulative prospect theory(CPT) is adopted. Travelers are assumed to choose the paths with the minimum perceived generalized path costs, consisting of time prospect value(PV) and monetary cost. At equilibrium with a given TCS, the endogenous reference points and credit price remain constant, and are consistent with the equilibrium flow pattern and the corresponding travel time distributions of road sub-network. To describe such an equilibrium state, the CPT-based stochastic user equilibrium(SUE) conditions can be formulated under TCS. An equivalent variational inequality(VI) model embedding a parameterized fixed point(FP) model is then established, with its properties analyzed theoretically. A heuristic solution algorithm is developed to solve the model, which contains two-layer iterations. The outer iteration is a bisection-based contraction method to find the equilibrium credit price, and the inner iteration is essentially the method of successive averages(MSA) to determine the corresponding CPT-based SUE network flow pattern. Numerical experiments are provided to validate the model and algorithm.