两种强制一阶电路中的跳跃随机性

通过对单结管一阶 RC 强制电路和单结管一阶 RL 强制电路中混沌行为的研究,发现单结管的跳跃随机性,跳跃随机性表现出单结管非线性伏安特性曲线的不唯一性和不确定性,并能在不同的初始条件和参数条件下产生形形色色的跳跃随机曲线。

节点间含源电路的简化分析法

节点分析法是学习分析线性时不变网络以及进行计算机辅助网络分析的基本方法之一.文中将含独立源电路的改进节点分析法,推广到既含独立源又含受控源的电路.计算结果表明,这种方法可以极大地简化含源电路的分析过程.

含有无伴电压源电路中节点电压法的研究

介绍并比较了用节点电压法分析、求解含有无伴电压源及无伴受控电压源电路的3种方法.改进的节点电压法将受控源和独立电源一样对待,同时简化了列写方程的过程,减少了方程的数量,因此,极大地简化了问题的求解难度.对于含有超级节点的电路,此方法具有其他方法无法比拟的优越性.

轨道车辆用空调电加热器设计应用注意事项

轨道车辆设计中,为满足室内温度环境要求,需根据运用环境,配置一定功率的电加热器。电加热器一般设计布置在车辆空调设备内、送风单元内、送风风道内、车厢的座椅旁的窗下、司机室足部区域、机械师室、卫生间和通过台等位置。轨道车辆是公共运输设备,安全运行是重中之重。电加热器产品安全运行对车辆安全运营影响重大,其质量在设计、制造、检验等环节应严格按相关标准执行和控制。就车辆用空调设备内强制通风电加热器(管式加热器)的设计应用注意事项进行初步阐述和分享,为车辆空调设备用强制通风电加热器合理设计、安全应用提供参考。

阴极保护工程设计中的若干问题

对目前阴极保护工程设计中有关保护方式的选择、强制电流法辅助阳极地床设计、牺牲阳极的选择和布置、保护电流需要量、绝缘法兰、套管屏蔽以及长效参比电极等方面存在的问题进行了探讨。

新型婴儿保温箱的设计

目的:研制具有强制保护电路的婴儿保温箱,以确保婴儿保温箱的工作安全可靠。方法:建立温度数据库,采用Cygnal F005单片机作为智能部件,通过对比的方法准确判断传感器的工作状态;采用双重温度控制系统,确保仪器工作在正常温度范围。仪器发生电路故障可自动切换到强制保护电路,维持保温箱内温度,确保婴儿健康。结果:新型婴儿保温箱的设计确保了电路温度控制精确,工作状态可靠,能够为新生儿提供一个空气洁净、温湿度适宜的舒适安全的环境。结论:婴儿保温箱的性能稳定,精度高,安全可靠,操作方便。

基于Cygnal F005单片机的新型婴儿保温箱的实验研究

现为了确保婴儿保温箱的工作安全可靠,用Cygnal F005单片机作为智能部件,研制出具有强制保护电路的婴儿保温箱。该仪器建立了温度数据库,通过对比的方法准确判断传感器的工作状态;采用了双重温度控制系统,确保仪器工作在正常温度范围;仪器发生电路故障可自动切换到强制保护电路维持保温箱内温度,确保婴儿安全。其性能稳定、精度高、安全可靠、操作方便。

Ionization Suppression of Heteronuclear Diatomic and Triatomic Molecules in Strong Infrared Laser Fields

Ionization is the fundamental process in interaction of atoms/molecules with femtosecond strong laser fields. Comparing to atoms, molecules exhibit peculiar behaviors in strong-field ionization because of their diverse geometric structures, molecular electronic orbitals as well as extra nuclear degrees of freedom. In this study, we investigate strong field single and double ionization of carbon monoxide （CO） and carbon dioxide （CO2） in linearly polarized 50-fs, 800-nm laser fields with peak intensity in the range of 2×10 13 W/cm2 to 2×10 14 W/cm2 using time-of-flight mass spectrometer. By comparing the ionization yields with that of the companion atom krypton （Kr）, which has similar ionization potential to the molecules, we investigate the effect of molecular electronic orbitals on the strong-field ionization. The results show that comparing to Kr, no significant suppression is observed in single ionization of both molecules and in non-sequential double ionization （NSDI） of CO, while the NSDI probability of CO2 is strongly suppressed. Based on our results and previous studies on homonuclear diatomic molecules （N2 and O2）, the mechanism of different suppression effect is discussed. It is indicated that the different structure of the highest occupied molecular orbitals of CO and CO2 leads to distinct behaviors in two-center interference by the electronic wave-packet and angular distributions of the ionized electrons, resulting in different suppression effect in strong-field ionization.

Polymer nanocomposite dielectrics with high electrocaloric effect for flexible solid-state cooling devices

Nanocomposite dielectrics show great promising application in developing next generation wearable all-solidstate cooling devices owing to the possessed advantages of high cooling efficiency, light-weight and small volume without the induced greenhouse effect or serious harm to ozone layer in the exploited refrigerants. However, low electrocaloric strength in nanocomposite dielectric is severely restricting its wide-spread application because of high applied operating voltage to improve electrocaloric effect. After addressing the chosen optimized ferroelectric ceramic and ferroelectric polymer matrix in conjunction with the analysis of crucial parameters, recent progress of electrocaloric effect(ECE) in polymer nanocomposites has been considerably reviewed. Subsequently, prior to proposing the conceptual design and devices/systems in electrocaloric nanocomposites, the existing developed devices/systems are reviewed. Finally, conclusions and prospects are conducted, including the aspects of materials chosen, structural design and key issues to be considered in improving electrocaloric effect of polymer nanocomposite dielectrics for flexible solidstate cooling devices.

A new braking force distribution strategy for electric vehicle based on regenerative braking strength continuity

Regenerative braking was the process of converting the kinetic energy and potential energy, which were stored in the vehicle body when vehicle braked or went downhill, into electrical energy and storing it into battery. The problem on how to distribute braking forces of front wheel and rear wheel for electric vehicles with four-wheel drive was more complex than that for electric vehicles with front-wheel drive or rear-wheel drive. In this work, the frictional braking forces distribution curve of front wheel and rear wheel is determined by optimizing the braking force distribution curve of hydraulic proportional-adjustable valve, and then the safety brake range is obtained correspondingly. A new braking force distribution strategy based on regenerative braking strength continuity is proposed to solve the braking force distribution problem for electric vehicles with four-wheel drive. Highway fuel economy test(HWFET) driving condition is used to provide the speed signals, the braking force equations of front wheel and rear wheel are expressed with linear equations. The feasibility, effectiveness, and practicality of the new braking force distribution strategy based on regenerative braking strength continuity are verified by regenerative braking strength simulation curve and braking force distribution simulation curves of front wheel and rear wheel. The proposed strategy is simple in structure, easy to be implemented and worthy being spread.

Force Sensing Resistor and Its Applicationto Robotic Control

Abstract: The force sensing resistor (FSR) and its con’struction and characteristic are described. By using the optimal electronic interface, the end result which is a direct proportionality between force and voltage is obtained. The circuits of application for force and position measurements in the robotic control are given. The experiment that FSRs are placed on the fingers of BH - 1 dexterous hand as tactile sensors to measure the contacting forces shows FSR’s force sensitivity is optimized for use in the control of robot contacting with environment.

Effect of nanoclay on properties of porous PVdF membranes

The main requirements for battery separators are high porosity which can serve pathways of lithium ion and space for gel electrolytes to impregnate in a membrane and mechanical strength to allow easy handling for battery assembly. Generally, it appears the trade-off relationship between the porosity and mechanical strength of the membrane. PVdF composite membranes containing nano-size clays were used to improve the mechanical strength of the membrane without affecting the membrane porosity. The composite membranes were prepared by phase inversion method controlling the membrane preparation conditions such as retention time. The resultant membranes show increased mechanical properties with similar membrane porosity around 80 % compared to the pristine PVdF membrane. Incorporation of nonoclay can be considered as an effective method to improve the mechanica! strength in porous membrane supports, especially in a separator.

Spain is Different Mass Tourism and Gender Idendities in the Sixties

In Spain, the historical context of the sixties was experienced as a particularly changing one. Gone were the post-war years, and with them the autarchy, poverty and famine, characteristics of that time. After a transitory fifties decade, the country entered a prosperous time, which is known as the develompentism sixties--desarrollismo. The franscoism itself promoted this change. Meanwhile, it became a mandatory to guide the population so the fostered modem life did not imply, among other issues, an abandonment of the traditional gender order. Popular cinema played a key role in that objective. Particularly tourism narratives had direct implications on the renewed way to understand gender identities. In this article we will approach two blockbusters, as representative examples of the mainstream films productions, through which analyse how masculinity and femininity were screened and considered.

Automatic Organization, Thinking Motion and Dynamics of the Universe

There are many automatic organization phenomena and automatic organization unities in the universe. The automatic organization whole refers to a life body with the thinking. The thinking is the core of automatic organization. The thinking is at eternal restless motion and binds to substances. The universe, organism and society are the automatic organization unities or life systems with the thinking. The thinking can perceive, attract, drive, organize and control all individuals and it is a force of life structure or universal gravitation and universal repulsion. The thinking has a life structure, a template and dynamic of entity-life＇s automatic organization. Life body has five dynamic systems： the thinking motion and information flow, breathing motion, closed-loop current （particle flow） and energy flow, interaction among state-varying, state-stabilizing and control organizations and active ＆ automatic chemical-physical reactions, cardiac pulsation and active motion and transportation. Human, galaxies and society can change from low to high energy state initiatively. This is realized by controlling the desires of life entity via the thinking and breathing motions and by altering the body＇s binding forces dominating the life entity （in turn, by bond force, strong interaction and quark confinement）. All forces in the universe present in the universe of life： force of the thinking-universal gravitation and universal repulsion, electromagnetic interaction, bond force, strong interaction, quark confinement and weak interaction. Under the automatic organization of the thinking, these forces bind into a 4-season＇ whole. The united state of these forces is controlled by the thinking and breathing motion, which is capable of changing from 3-, 2- and 1-dimensional states to a 0-dimensional state.

Dust Diffusion Simulation in the Third Layer Construction of Underground Powerhouse

Under forced ventilation,the dust diffusion of underground powerhouse construction is investigated using a 3D high Reynolds number k-ε model.The interfacial momentum transfers and the wall roughness in the wall function are considered.Ventilation in the third layer of underground powerhouse of Xiangjiaba hydropower station is used as a case.The geometric structure has a decisive effect on the airflow distribution.It is concluded that the dust concentration decreases gradually with the increase of the ventilation time.However,iso-concentration curves have the same tendency after 1 800 s.The dust concentration meets the ventilation and dust-prevention health standard after 2 300 s.The prediction by the present model is confirmed by the experimental measurement by Nakayama.

Enhanced electrochemical stimuli multilayers based on a ferrocene-containing polymer

Based on the noncovalent functionalization of ferrocene-grafted polyethylenimine （PEI-Fc） and carbon nanotubes （CNTs）, CNT bundles are exfoliated by PEI-Fc solution and thus form stable compounds PEI-Fc@CNTs, which is used to construct the PEI-Fc@CNTs/DNA multilayers through layer-by-layer assembly. The multilayers show a highly uniform and homogeneous characteristic, which significantly improve the electrical property of the multilayers. Upon the oxidation electrical potential, the ferrocene groups are switched from reduction state （[Fe（C5H5）2]） to oxidation state （[Fe（C5H5）2]^＋）, leading to change of microenvironments＇ charge density, resulting in swelling of the multilayers and a final degree of swelling of 37 % and the decrease of multilayer stiffness. We maintain that electrochemical control over the swelling behavior of multilayers could have important implications for responsive coatings of nanoscale devices, including mechanically tunable surfaces which are used to modulate cellular activities and control drug delivery.

Long life rechargeable Li-O_2 batteries enabled by enhanced charge transfer in nanocable-like Fe@N-doped carbon nanotube catalyst

Rechargeable Li-O2 batteries have attracted considerable interests because of their exceptional energy density. However, the short lifetime still remained as one of the bottle-neck obstacles for the practical application of rechargeable Li-O2 batteries. The development of efficient cathode catalyst is highly desirable to reduce the energy barrier of Li-O2 reaction and electrode failure. In this work, we report a facile strategy for the fabrication of a high-per- formance cathode catalyst for rechargeable Li-O2 batteries by the encapsulation of high content of active Fe nanorods into N-doped carbon nanotubes with high stability （denoted as Fe@NCNTs）. First-principles calculations reveal that the synergistic charge transfer and redistribution between the interface of Fe nanorods, the CNT walls and the active N dopants greatly facilitate the chemisorption and subsequent dissociation of O2 molecules into the epoxy intermediates on the carbon surface, which benefits the uniform growth of nanosized discharge products on CNT surface and thus boosts the reversibility of Li-O2 reactions. As a result, the cathode with Fe@NCNT catalyst exhibRs long cycling sta- bility with high capacities （1000 mA h g-1 for 160 cycles and 600 mA h g-t for 270 cycles）. Based on the total mass of Fe@NCNTs ＋ Li2O2, high gravimetric energy densities of 2120-2600 W h kg-~ can be achieved at the power densities of 50-795 W kg-1.

Forced Convective Air Cooling from Electronic Component Arrays in a Parallel Plate Channel

This paper discusses air forced convection heat transfer from inline protruding elements arranged in eight rows. The streamwise and spanwise spacings between elements were varied using a splitter plate that can be positioned at three different modular configurations. A set of empirical formulas waspresented to correlate the experimental data for the design of air cooling systems. Arrays of components with one odd-size module have been tested also. Experimental results show that blocks near the entrance and behind the odd-size module have improved performance compared with uniform arrangements. Accordingly, temperature sensitive components are suggested to be arranged in these locations.

Engineering the heterogeneous interfaces of inverse opals to boost charge transfer for efficient solar water splitting

Herein,we report a three-dimensional porous TiO_(2)/Fe_(2)TiO_(5)/Fe_(2)O_(3)(TFF)inverse opal through in situ thermal solid reactions for photoelectrochemical water splitting.The Fe_(2)TiO_(5) interfacial layer within TFF acting as a bridge to tightly connect to TiO_(2) and Fe_(2)O_(3) reduces the interfacial charge transfer resistance,and suppresses the bulk carrier recombination.The optimized TFF displays a remarkable photocurrent density of 0.54mAcm^(-2) at 1.23V vs.reversible hydrogen electrode(RHE),which is 25 times higher than that of TiO_(2)/Fe_(2)O_(3)(TF)inverse opal(0.02mAcm^(-2) at 1.23V vs.RHE).The charge transfer rate in TFF inverse opal is 2-8 times higher than that of TF in the potential range of 0.7-1.5V vs.RHE.The effects of the Fe_(2)TiO_(5) interfacial layer are further revealed by X-ray absorption spectroscopy and intensity-modulated photocurrent spectroscopy.This work offers an interfacial engineering protocol to improve charge separation and transfer for efficient solar water splitting.