重度阻塞性睡眠呼吸暂停患者脑电能量密度分布及变化规律分析

目的阻塞性睡眠呼吸暂停(obstructive sleep apnea,OSA)是一种在临床有较高病发率的睡眠障碍,其病发机制为上气道在睡眠期间反复阻塞,会引发低氧血症、频繁低通气、睡眠唤醒、呼吸暂停等病理生理改变。多导睡眠监测(polysomography,PSG)是临床上诊断OSA的金标准,可以监测患者睡眠期间的脑电波变化。本文通过分析重度OSA男性患者睡眠规律和脑电(electroencephalogram,EEG)能量密度分布及变化规律,探究重度OSA患者的睡眠脑电变化。方法选取30名男性重度OSA患者和30名男性正常对照组,对60名受试者进行整夜(8 h左右)的多导睡眠监测,对得到的睡眠特征和脑电参数进行整理,提取睡眠与脑电特征。对比睡眠监测得到的睡眠特征和其前额区的脑电能量密度。结果在睡眠特征方面,重度OSA患者睡眠期时间为370.20 min,睡眠效率平均为86.90%,非快速眼动1期平均占比19.90%,非快速眼动2期平均占比42.55%,对比正常人睡眠时间、睡眠效率以及非快速眼动1期、2期占比明显降低。在脑电特征方面,重度OSA患者整夜睡眠θ波的绝对能量密度、总能量密度、相对能量密度delta波、K复合波的相对能量密度高于对照组,β波相对功率低于对照组。OSA患者脑电低频活动增加明显。结论随着OSA患者严重程度的加重,患者的脑电能量与低频活动增加明显,为OSA患者疾病的发展趋势和评估疗效提供了重要的参考依据。

重度阻塞性睡眠呼吸暂停患者不同睡眠期脑电能量密度分布及变化规律

目的分析重度阻塞性睡眠呼吸暂停患者（OSA）不同睡眠时期的脑电能量密度分布及其变化规律。方法前瞻性纳入天津医科大学总医院呼吸与危重症医学科收治的重度OSA患者15例为OSA组，其中男9例，女6例，年龄27-60岁，平均（45±15）岁；同期健康体检者12名为对照组，其中男7名，女5名，年龄26-61岁，平均（44±16）岁。计算和比较两组在清醒期、睡眠一期、睡眠二期、睡眠三期和快速眼动期16通道脑电网δ, θ, α, σ, β 及 γ频段的能量密度，观察差异显著的特征睡眠期、特征频段和特征脑区，并与睡眠监测指标进行相关性分析。结果两组患者清醒期脑电能量密度分别为（0．82±0．13）和（0．66±0．02）μV^2／Hz，睡眠一期分别为（1．28±0．07）和（0．92±0．04）μV^2／Hz，睡眠三期分别为（2．74±0．22）和（2．04±0．07）μV^2／Hz，组间比较差异均有统计学意义（t=4．309，-3．369，-2．669，均P〈0．05）。OSA组δ频段能量密度较对照组显著增强，进一步分析发现两组δ频段的脑电能量密度差异主要集中在清醒期的额区[（0．90±0．02），（0．66±0．02）μV^2／Hz，t=8．539，P〈0．01]和中央区[（1．15±0．06），（0．72±0．02）μV^2／Hz，t=6．669，P〈0．01]，睡眠一期的额区[（1．23±0．03），（0．99±0．03）μV^2／Hz，t=5．983，P〈0．01]和中央区[（1．52±0．05），（1．14±0．04）μV^2／Hz，t=5．714，P〈0．01]以及睡眠三期的中央区[（3．2±0．17），（2．71±0．08）μV^2／Hz，t=2．707，P〈0．05]。脑电能量密度分布与主要睡眠监测指标的相关性分析结果显示，重度OSA患者在睡眠一期和三期8频段中央区的脑电能量密度与微觉醒指数呈正相关（r值分别为0．877、0．656），提示OSA患者的睡眠片段化与其夜间睡眠脑电的能量变化密切相关。结论重度OSA患者的睡眠特征期为清醒期、睡眠一期和三期，其脑电δ频段能量密度显著增强，主要发生在清醒期、睡眠一期的额区和中央区以及睡眠三期期的中央区，表明重度OSA患者脑电在额区和中央区为主的脑区呈现慢波化现象，提示阻塞性睡眠呼吸暂停可能导致OSA患者的额区和中央区脑区神经功能受损。

铁磁介电体的复数介电常数及储能与损耗功率

对均匀电场作用下的铁磁介电体的介电性质的理论分析,引入了铁磁介电体的复数介电常数,求得单位时间内铁磁介电体中的平均储存电能量密度和介电损耗功率的计算公式。

Fabricating a Micro Electromagnetic Actuator with High Energy Density

This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.

Effect of the amount of zinc-doped on the electrochemical performance of nickel hydroxide

The nickel hydroxide prepared by micro-emulsion method was doped by coprecipitated Zn. The effect of the amount of zinc-doped on the properties of Ni(OH)2 such as the reversibility of the electrode reaction, the charge efficiency and active material utilization ratio of nickel electrode, and discharge specific capacity was studied by cyclic voltammetry and constant current charge-discharge tests. The results indicate that the specific discharge capacity of nickel hydroxide obtained by micro-emulsion method is much less than its theoretical value because the transfer of electrons and the diffusion of protons H+ are hindered owing to its crystal grain size in a nanometer range and thus possessing higher crystal interface resistance. The crystal cells are swelled and the crystal defects increased in prepared material due to part of Ni2+ substituted by Zn2+ when zinc and nickel hydroxide are coprecipitated. Hence, the electrons and protons H+ in the electrode reaction are transferred easily, the electrochemical behavior of nickel electrode is improved and discharge specific capacity is promoted. However, the performance of Ni(OH)2 is gradually enhanced with the addition of zinc-doped at first, while slowly decreased after the content of zinc is added to a certain value. The best electrode reaction reversibility, the highest electrode charge efficiency, the highest active material utilization ratio and the largest specific capacity on discharge are available when the mass fraction of Zn doped in nickel hydroxide by coprecipitation reaches 2.5 %.

三元正极材料清洗废水资源化回收零排放处理工艺

锂电三元正极材料在清洗过程中产生含有Li^(+)、Al^(3+)、SO_(4)^(2-)、镍钴锰氧化物及少量其他离子的废水,对该三元正极材料清洗废水的资源化回收零排放处理工艺进行了阐述。该废水处理系统涉及的成套工艺包括预处理单元、废水减量化单元、沉锂单元和制纯水单元。重点对Al^(3+)的去除、膜浓缩、沉锂等关键工艺进行了重点描述,最后通过实际与理论对比分析,达到了预期的设计目标——锂资源得到有效回收、废水实现全部回用。通过对实际案例的相关数据的例举和分析,证明了本套废水处理工艺的可行性和可靠性,为锂电三元正极材料清洗废水的治理提供了典型的参考工艺路线。

Electron Acceleration and Bunch Generation by Intense Femtosecond Laser Pulse in Preplasma of a Target

We present analytical studies of electron acceleration in the low-density preplasma of a thin solid target byan intense femtosecond laser pulse.Electrons in the preplasma are trapped and accelerated by the ponderomotive forceas well as the wake field.Two-dimensional particle-in-cell simulations show that when the laser pulse is stopped by thetarget,electrons trapped in the laser pules can be extracted and move forward inertially.The energetic electron bunchin the bubble is unaffected by the reflected pulse and passes through the target with small energy spread and emittance.There is an optimal preplasma density for the generation of the monoenergetic electron bunch if a laser pulse is given.The maximum electron energy is inverse proportion to the preplasma density.

Effects of oxidation treatment on properties of SiO_(2f)/SiO_2-BN composites

The silica fiber reinforced silica and boron nitride-based composites （SiO2f/SiO2-BN） were prepared firstly via the sol-gel method and then the urea route, and the effects of oxidation treatment on the component, structure, mechanical and dielectric properties of the composites were investigated. The results show that the oxidation treatment at 450 ℃ will not impair the structure of boron nitride, and carbon is the main impurity with the excessive urea. The density of SiO2f/SiO2-BN composites is 1.81 g/cm3, and the flexural strength and elastic modulus are 113.9 MPa and 36.5 GPa, respectively. After oxidation treatment, the density varies to 1.80 g/cm3, and the flexural strength and elastic modulus are decreased to 58.9 MPa and 9.4 GPa, respectively. The mechanical properties of the composites are severely damaged, but they still exhibit a good toughness. The composites show excellent dielectric properties with the dielectric constant and loss tangent being 3.22 and 0.003 9, respectively, which indicates that the oxidation treatment is ineffective to improve the dielectric properties of SiOzf/SiO2-BN composites.

Compact Electric Energy Storage for Marine Vehicles Using on-Board Hydrogen Production

The use of electric energy in marine vessels has been increasing in recent years. In general, it is motivated by the low ecological impact. However, in the case of underwater vehicles it is functionally essential. The objective of this study is to demonstrate the advantage of electric power generation and storage based on on-board hydrogen generation via the reaction between activated aluminum and water and application of the hydrogen in a fuel cell. The original activation process enabling a spontaneous reaction with water to produce hydrogen as well as a parametric study of hydrogen generation rate and yield are briefly described. The potential increase in specific energy （energy per unit mass） and energy density （energy per unit volume） vs. batteries and other means of hydrogen storage is presented. It is shown that the use of the present technology may result in a substantial increase of specific electric energy along with a reduction in volume or an increase in operating time for the same overall mass of energy storage and generation system.

Electronic and Magnetic Properties of Double Perovskite Ca_2CrSbO_6

First-principles calculations have been performed for the study of the electronic band structure and ferromagnetic properties of double perovskite Ca2CrSbO6. The density of states, total energy, spin magnetic moment, and charge density were calculated and analyzed in details. It is found that Ca2CrSbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is about 2.99#B. The chromium contributes the most in the total magnetic moments. The results indicate that Ca2CrSbO6 is half-metallic.

Electrochemical Energy Storage Technologies and Applications

The current need to fasten the implementation of renewable energies greatly depends on the development of competitive storage devices, and while there is not a single technology which is likely capable to competitively cover the wide range of possible demands, electrochemical technologies are one of the most promising for many of them. For the realization of this promise, new materials fulfilling criteria such as high energy density, high power density, competitive cost, reliability, and environmental compatibility need to be developed in the near future. Electrochemical energy storage devices can be classified into two main technologies： supercapacitors and batteries （including redox flow batteries）. Materials and applications for these technologies are discussed and compared, listing current status, technical and strategic challenges.

First-principles study on mechanical properties of LaMg_3 and LaCuMg_2

Abstract： With the substitution of part Mg in LaMg3 by Cu, the elastic constants CH and C12 increase while C44 decreases, implying an enhanced Poisson effect and smaller resistance to 〈001〉（100） shear. Furthermore, the bulk modulus B increases, while the shear modulus G, elastic modulus E and anisotropie ratio A are reduced. The calculated Debye temperature of LaCuMg2 is lower, implying the weaker interaction between atoms in LaCuMg2. Then, the stress-strain curves in entire range and the ideal strength at critical strain are studied. The present results show that the lowest ideal tensile strength for LaMg3 and LaCuMg2 is in the 〈100〉 direction. The ideal shear strength on the 〈 1 ^-1 0〉（110） slip system of LaMg3 is greater than LaCuMg2. The density of states and charge density distribution are further studied to understand the inherent mechanism of the mechanical properties.

The application of metal-organic frameworks and their derivatives for lithium-ion capacitors

There is an urgent need for lithium-ion capacitors(LICs)that have both high energy and high power densities to meet the continuously growing energy storage demands.LICs effectively balance the high energy density of traditional rechargeable batteries with the superior power density and long life of supercapacitors(SCs).Nevertheless,the development of LICs is still hampered by limited kinetic processes and capacity mismatch between the cathode and anode.Metal-organic frameworks(MOFs)and their derivatives have received significant attention because of their extensive specific surface area,different pore structures and topologies,and customizable functional sites,making them compelling candidate materials for achieving high-performance LICs.MOF-derived carbons,known for their exceptional electronic conductivity and large surface area,provide improved charge storage and rapid ion transport.MOF-derived transition metal oxides contribute to high specific capacities and improved electrochemical stability.Additionally,MOF-derived metal compounds/carbons provide combined effects that increase both the capacitive and Faradaic reactions,leading to a superior overall performance.The review begins with an overview of the fundamental principles of LICs,followed by an exploration of synthesis strategies and ligand selection for MOF-based composite materials.It then analyzes the advantages of original MOFs and their derived materials,such as carbon materials and metal compounds,in enhancing LIC performance.Finally,the review discusses the major challenges faced by MOFs and their derivatives in LIC applications and offers future research directions and recommendations.

A review of negative electrode materials for electrochemical supercapacitors

With increasing demands for clean and sustainable energy, the advantages of high power density, high efficiency, and long life expectancy have made supercapacitors one of the major emerging devices for electrochemical energy storage and power supply. However, one of the key challenges for SCs is their limited energy density, which has hindered their wider application in the field of energy storage. Despite significant progress has been achieved in the fabrication of high-energy density positive electrodes materials, negative electrode materials with high capacitance and a wide potential window are relatively less explored. In this review, we introduced some new negative electrode materials except for common carbon-based materials and what's more, based on our team's work recently, we put forward some new strategies to solve their inherent shortcoming as electrode material for SCs.

Tailoring electrolyte enables high-voltage Ni-rich NCM cathode against aggressive cathode chemistries for Li-ion batteries

The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(Ni-rich NCM)cathode materials suffer from electrochemical performance degradation upon cycling due to detrimental cathode interface reactions and irreversible surface phase transition when operating at a high voltage(≥4.5 V).Herein,a traditional carbonate electrolyte with lithium difluoro(oxalato)borate(Li DFOB)and tris(trimethylsilyl)phosphate(TMSP)as dual additives that can preferentially oxidize and decompose to form a stable F,B and Si-rich cathode-electrolyte interphase(CEI)that effectively inhibits continual electrolyte decomposition,transition metal dissolves,surface phase transition and gas generation.In addition,TMSP also removes trace H_(2)O/HF in the electrolyte to increase the electrolyte stability.Owing to the synergistic effect of Li DFOB and TMSP,the Li/LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) half cells exhibit the capacity retention 76.3%after 500 cycles at a super high voltage of 4.7 V,the graphite/LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)full cells exhibit high capacity retention of 82.8%after 500 cycles at 4.5 V,and Li/LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)pouch cells exhibit high capacity retention 94%after 200 cycles at 4.5 V.This work is expected to provide an effective electrolyte optimizing strategy compatible with high energy density lithium-ion battery manufacturing systems.

High-energy cathode materials for Li-ion batteries: A review of recent developments

Lithium ion batteries （LIBs） represent one of the most promising solutions for environmentally friendly transportation such as electric vehicles. The demand for high energy density, low cost and environmentally friendly batteries makes high-capacity cathode materials very attractive for future LIBs. Layered LiNixCoyMn2O2 （x＋y＋z=1）, Li-rich oxides and Li-V-O compounds have attracted much attention due to their high capacities in recent years. In this review, we focus on the state-of-the-art research activities related to LiNixCoyMn2O2, Li-rich oxides and Li-V-O compounds, including their structures, reaction mechanisms during cycling, challenges and strategies that have been studied to improve their electrochemical performances.

NiMoCo layered double hydroxides for electrocatalyst and supercapacitor electrode

Non-noble-metal electrode materials with high durability and efficiency have become the frontiers of energy conversion and storage fields.However,conventional electrode materials often show high overpotential and low conductivity.To solve this problem,we fabricate a NiMoxCo2−x layered double hydroxide(LDH)/Ni foam(NF)product through a facile hydrothermal route.The as-prepared NiMo-Co-LDH/NF catalyst possesses an overpotential of 123 mV for hydrogen evolution reaction(HER)at 10 mA cm^−2 and 279 mV for oxygen evolution reaction(OER)at 20 mA cm^−2.The as obtained product exhibits excellent overall water splitting performances.Meanwhile,as the electrode material for supercapacitor,it delivers high specific capacitance and excellent cyclic performance.The asymmetric supercapacitor assembled with NiMoCo-LDH/NF//active carbon exhibits 93%of its initial capacity after 8000 cycles.

Advances of graphene application in electrode materials for lithium ion batteries

The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we provide an overview of recent progress in graphene-based electrode materials. Graphene with its great electrical conductivity and mechanical properties have apparently improved the performance of traditional electrode materials. The methods and electrochemical properties of advanced graphene composite as cathode and anode for LIBs are reviewed. Two novel kinds of graphene hybrid materials are specially highlighted: three-dimensional porous and flexible binder-free graphene-based materials. Challenges for LIBs and future research trend in the development of high-performance electrode materials are further discussed.

Cracked bark-inspired ternary metallic sulfide(NiCoMnS_(4)) nanostructure on carbon cloth for high-performance aqueous asymmetric supercapacitors

In this paper,we report a high-performance selfsupported supercapacitor electrode composed of a cracked bark-shaped Ni-Co-Mn ternary metallic sulfide(NiCoMnS4)nanostructure on carbon cloth prepared by a simple one-step hydrothermal process and subsequent electrochemical treatment.The electrode delivers a high specific discharge capacity of up to 2470.4 F g^(-1) at 1 A g^(-1) and high rate performances of1635.6 F g^(-1) at 10 A g^(-1) and 910.2 F g^(-1) even at 32 A g^(-1).Cycling tests indicate that NiCoMnS_(4) could maintain >91.1% of its initial capacity and nearly 100% Coulombic efficiency over10,000 cycles at 8 A g^(-1).An aqueous asymmetric supercapacitor assembled with NiCoMnS_(4) as the cathode,activated carbon as the anode,and 1 mol L^(-1) KOH as the electrolyte delivers an energy density of 68.2 W h kg^(-1)at 850.1 W kg^(-1) and capacity retention of 92.5% after 10,000 cycles at 4 A g^(-1).Given the excellent performance and simple material preparation of our proposed device,this study provides a valuable foundation for the development of self-supported metallic sulfide-based electrodes with high electrochemical properties for potential application in aqueous asymmetric supercapacitors.

A durable P2-type layered oxide cathode with superior low-temperature performance for sodium-ion batteries

To power large-scale energy storage systems,sodium-ion batteries(SIBs)must have not only high-energy density but also high performance under a low-temperature(LT)environment.P2-type manganese oxides with high specific capacity are promising cathode candidates for SIBs,but their LT applications are limitedly explored.We proposed a P2-type Na_(0.67)Ni_(0.1)Co_(0.1)Mn_(0.8)O_(2) material with outstanding LT performance prepared through reasonable structure modulation.The material offers an excellent Na^(+) diffusion coefficient(approximately 10^(−9)-10^(−7.5) cm^(2) s^(−1))at−20℃,a superior LT discharge capacity of 147.4 mA h g^(−1) in the Na half-cell system,and outstanding LT full cell performance(energy density of 358.3 W h kg^(−1)).Various characterisations and density function theory calculations results show that the solid solution reaction and pseudocapacitive feature promote the diffusion and desolvation of Na+from the bulk electrode to interface,finally achieving superior electrochemical performance at LT.