Simultaneous guidance of electromagnetic and elastic waves via glide symmetry phoxonic crystal waveguides

A phoxonic crystal waveguide with the glide symmetry is designed,in which both electromagnetic and elastic waves can propagate along the glide plane at the same time.Due to the glide symmetry,the bands of the phoxonic crystal super-cell degenerate in pairs at the boundary of the Brillouin zone.This is the so-called band-sticking effect and it causes the appearance of gapless guided-modes.By adjusting the magnitude of the glide dislocation the edge bandgaps,the bandgap of the guided-modes at the boundary of the Brillouin zone,can be further adjusted.The photonic and phononic guided-modes can then possess only one mode for a certain frequency with relatively low group velocities,achieving single-mode guided-bands with relatively flat dispersion relationship.In addition,there exists acousto-optic interaction in the cavity constructed by the glide plane.The proposed waveguide has potential applications in the design of novel optomechanical devices.

Accurately tracking hypersonic gliding vehicles via an LEO mega-constellation in relay tracking mode

In order to effectively defend against the threats of the hypersonic gliding vehicles(HGVs),HGVs should be tracked as early as possible,which is beyond the capability of the ground-based radars.Being benefited by the developing megaconstellations in low-Earth orbit,this paper proposes a relay tracking mode to track HGVs to overcome the above problem.The whole tracking mission is composed of several tracking intervals with the same duration.Within each tracking interval,several appropriate satellites are dispatched to track the HGV.Satellites that are planned to take part in the tracking mission are selected by a new derived observability criterion.The tracking performances of the proposed tracking mode and the other two traditional tracking modes,including the stare and track-rate modes,are compared by simulation.The results show that the relay tracking mode can track the whole trajectory of a HGV,while the stare mode can only provide a very short tracking arc.Moreover,the relay tracking mode achieve higher tracking accuracy with fewer attitude controls than the track-rate mode.

Gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis for ammonia production

Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis.In this method,NO_(x)is provided by the gliding arc discharge and then electrolyzed by Cu/Cu_(2)O after alkaline absorption.The electrical characteristics,the optical characteristics and the NO_(x)production are investigated in discharges at different input voltage and the gas flow.The dependence of ammonia production through Cu/Cu_(2)O electrocatalysis on pH value and reduction potential are determined by colorimetric method.In our study,two discharge modes are observed.At high input voltage and low gas flow,the discharge is operated with a stable plasma channel which is called the steady arc gliding discharge mode(A-G mode).As lowering input voltage and raising gas flow,the plasma channel is destroyed and high frequency breakdown occurs instead,which is known as the breakdown gliding discharge mode(B-G mode).The optimal NO_(x)production of 7.34 mmol h^(-1)is obtained in the transition stage of the two discharge modes.The ammonia yield reaches0.402 mmol h^(-1)cm^(-2)at pH value of 12.7 and reduction potential of-1.0 V versus reversible hydrogen electrode(RHE).

阻塞性睡眠呼吸暂停综合征患者Glide Scope视频喉镜和Macintosh喉镜气管插管效果比较

目的:比较Glide Scope视频喉镜与Macintosh喉镜在阻塞性睡眠呼吸暂停综合征(OSAS)患者引导气管插管中的应用效果。方法:择期行悬雍垂腭咽成形术的OSAS患者60例,分为Glide Scope视频喉镜组(G组,n=30)和Macintosh喉镜组(M组,n=30)。术前应用改良Mallampati法对所有患者进行气道评估,诱导后分别用两种喉镜引导经鼻气管插管,记录Cormack-Lehane分级、插管时间及插管前后平均动脉压(pMA)、心率(fH)变化情况,计算首次插管成功率。结果:G组声门显露程度优于M组(Z=3.907,P<0.001),插管后G组pMA和fH的变化较M组明显轻微(t=2.473、2.647,P<0.05),首次插管成功率G组(86.7%)明显高于M组(63.3%)。结论:与Macintosh喉镜相比,Glide Scope视频喉镜能明显改善OSAS患者临床插管条件,可作为一种有效的插管工具推广应用。

Optimal Matching Analysis of Net Buoyancy and Pitching Angle for Underwater Gliders

Control parameter optimization is an efficient way to improve the endurance of underwater gliders(UGs),which influences their gliding efficiency and energy consumption.This paper analyzes the optimal matching between the net buoyancy and the pitching angle and proposes a segmented control strategy of Petrel-L.The optimization of this strategy is established based on the gliding range model of UG,which is solved based on the approximate model,and the variations of the optimal control parameters with the hotel load are obtained.The optimization results indicate that the segmented control strategy can significantly increase the gliding range when the optimal matching between the net buoyancy and the pitching angle is reached,and the increase rate is influenced by the hotel load.The gliding range of the underwater glider can be increased by 10.47%at a hotel load of 0.5 W.The optimal matching analysis adopted in this study can be applied to other UGs to realize endurance improvement.

Brief Introduction of a New Kind of Glide Path Antenna

A new kind of image type glide path beacon subsystem of Instrument Landing System (ILS) was reported. Capture effect is designed to overcome far-field (FF) reflectors and rising terrain. Low angle CSB signal was highly depressed, was ?41 dB at 1? comparative to the max value. Both Carrier and Side Bands (CSB) and Side and Bands Only (SBO) signals were radiated by three antennas. Difference in Depth of Modulation (DDM) provided good linear variation around glide path angle (θ). At near field area, the site of near-field (NF) monitor was just about 57 m in front of the system, needed less length of reflection plane than that of M-array system, result from the system had only 90% of the M-Array antenna height.

ANALYSIS OF AERODYNAMIC CHARACTERISTIC ON GLIDE BULLET TO INCREASE RANGE

This paper mainly calculates, analyzes and compares the aerodynamic characteristics of two kinds of bullets, one has wing, and the other has no wing. The calculated results indicate that the lift force of the glide bullet with wing is much bigger than that has no wing, and it reached the aim to increase range.

INFLUENCE OF TWINNING AND DISLOCATION GLIDE DURING CREEP OF EQUIAXED AND LAMELLAR TiAl ALLOYS

The creep deformation of two near γ titanium aluminide alloys with equiaxed and lamellar structures have been studied to understand their behaviour as a function of microstructural evolution during the early stages of creep. The lamellar alloys exhibit more pronounced hardening during the primary stage of creep leading to a much better creep resistance and a minimum creep rate two orders of magnitude lower than that of the equiaxed alloys. TEM observations have confirmed that the active deformation mechanisms are the same for both alloys and microstructural states, namely extensive slip of single 1/2〈110〉 dislocations and mechanical twinning. The latter has been comfirmed to occur in a fraction of the grains that never exceeds 50% while 1/2〈110〉 dislocations are active within all the γ grains. The twins are only responsible for a small amount of strain but they lead to a subdivision of the microstructure and determine (directly or indirectly) the hardening process observed during the primary stage of creep. During the secondary stage the creep rate is determined by the unblocking of pinned dislocations by processes such as a pipe diffusion or cross slip that allow thermally activated glide of 1/2〈110〉 dislocations within the γ matrix.

Adaptive Constrained On-board Guidance Technology forPowered Glide Vehicle

To make full use of expanded maneuverability and increased range,adaptive constrained on-board guidance technology is the key capability for a glide vehicle with a double-pulse rocket engine,especially under the requirements of desired target changing and on-line reconfigurable control and guidance.Based on the rapid footprint analysis,whether the new target is within the current footprint area is firstly judged.If not,the rocket engine ignites by the logic obtained from the analysis of optimal flight range by the method of hp-adaptive Gauss pseudospectral method(hp-GPM).Then,an on-board trajectory generation method based on powered quasi-equilibrium glide condition(QEGC)and linear quadratic regulator(LQR)method is used to guide the vehicle to the new target.The effectiveness of the guidance method consisted of powered on-board trajectory generation,LQR trajectory tracking,footprint calculation,and ignition time determination is indicated by some simulation examples.

Experimental study on the improvement of spray characteristics of aero-engines using gliding arc plasma

A gliding arc plasma fuel atomization actuator suitable for aeroengines was designed,and a gliding arc plasma fuel spray experimental platform was built to address the fuel atomization problem in aeroengine combustion chambers.The spray characteristics for different airflows,fuel flows,and discharge voltages were analyzed using laser particle size analysis.The research shows that the fuel atomization effect is improved from the increased airflow.The decreased fuel flow not only reduces the injection pressure of the fuel but also changes the discharge mode of the gliding arc,which affects reductions in the discharge power and inhibits fuel atomization.Gliding arc discharges accelerate the breaking,atomization,and evaporation of fuel droplets while reducing the particle size,which increases the proportion of small droplets.Compared with the working conditions of plasma-assisted atomization without the gliding arc,the D0.5,D0.9,and average particle size of the fuel droplets are reduced by 4.7%,6.5%,and 4.1%,respectively,when the modulation voltage of the gliding arc power supply is 200 V.

Glide Scope视频喉镜在全麻气管插管中的应用

目的观察Glide Scope视频喉镜在全麻气管插管中应用的可行性。方法 60例择期手术准备行全麻气管插管患者,ASAⅠ～Ⅱ级,随机分为G组和P组,每组30例,术前处理和麻醉诱导相同。G组采用Glide Scope视频喉镜进行气管插管,P组采用普通直接喉镜进行气管插管。观察两组患者声门显露程度、插管次数、插管时间及手术前(T1)、诱导后(T2)、插管后1min(T3)、3 min(T4)、5 min(T5)的收缩压(SBP)、舒张压(DBP)、心率(HR)和插管操作引起的相关并发症。结果声门显露:G组30例均为1级。P组1级17例,2级7例,3级6例,两者相比差异有显著性(P<0.05)。插管时间:G组为(30±13)s,P组为(26±19)s,两组相比差异无显著性。血流动力学的变化两组无差异,但在T3时P组HR上升与术前(T1)相差异有显著性(P<0.05)。插管引起的相关并发症两组无差异。结论应用Glide Scope视频喉镜气管插管操作简单便捷,声门显露容易清晰,对咽喉部的刺激小,值得在临床推广应用。

Glide Scope视频喉镜在双腔支气管导管插管中的临床应用

目的评价Glide Scope视频喉镜应用于左侧双腔支气管导管插管中的应用价值。方法 ASA分级为Ⅰ、Ⅱ级择期胸科手术患者50例,随机平均分为Glide Scope视频喉镜(GSVL)组、Macintosh直接喉镜(MDLS)组,每组25例。分别观察Glide Scope视频喉镜和Macintosh型直接喉镜插左侧双腔支气管的到位情况、插管所用时间、气管损伤情况。结果 GSVL组25例均一次插入左主支气管,MDLS组2例旋转错位,4例反向错位,19例一次插入左主支气管,成功率为76%,两组比较差异有显著性(P<0.05);GSVL组较MDLS组的气管插管时间平均延长14s,GSVL组气管损伤发生率低于MDLS组,两组比较差异无显著性(P<0.05)。结论 G1ide Scope视频喉镜用于左侧双腔支气管插管时更容易暴露声门,插管成功率较高,且气管损伤小,但不能缩短插管时间。

Glide Scope可视喉镜与直接喉镜行气管插管对插管时间及咽喉损伤的影响

直视喉镜是全麻下气管插管最常用的工具，也是麻醉医生处理气道时的核心技能，尽管直视喉镜是气管插管的金标准，但意外的困难插管会增加病死率[1,2]。GlideScope可视喉镜（GS）是一种较新的插管工具，它可将气管插管整个过程变成可视操作，具有简便性、可控性和可视性，明显提高咽喉的暴露，减少对舌根部和咽喉部的刺激，然而关于插管时间以及对咽喉损伤没有明确定论[3,4]。

Glide Scope视频喉镜在气管插管患者留置胃管中的应用

目的探讨Glide Scope视频喉镜在气管插管患者留置胃管中的应用效果。方法将80例气管插管状态下需留置胃管的患者分为对照组和观察组各40例,对照组采用常规方法留置胃管,观察组在Glide Scope视频喉镜辅助下留置胃管,比较两组1次置管成功率和操作用时。结果观察组胃管置入操作用时较对照组短,1次置管成功率较对照组高,差异均有统计学意义(P<0.01);对照组有8例患者进行了3次以上的操作才置管成功。结论Glide Scope视频喉镜用于气管插管后患者留置胃管的操作,能提高置管1次成功率,缩短操作时间。

Plasma nitrogen fixation system with dual-loop enhancement for improved energy efficiency and its efficacy for lettuce cultivation

Plasma nitrogen fixation(PNF)has been emerging as a promising technology for greenhouse gasfree and renewable energy-based agriculture.Yet,most PNF studies seldom address practical application-specific issues.In this work,we present the development of a compact and automatic PNF system for on-site agricultural applications.The system utilized a gliding-arc discharge as the plasma source and employed a dual-loop design to generate NO_(x)from air and water under atmospheric conditions.Experimental results showed that the system with a dualloop design performs well in terms of energy costs and production rates.Optimal operational parameters for the system were determined through experimentation,resulting in an energy cost of 13.9 MJ mol^(-1)and an energy efficiency of 16 g kWh^(-1)for NO_(3)^(-)production,respectively.Moreover,the concentration of exhausted NO_(x)was below the emission standards.Soilless lettuce cultivation experiments demonstrated that NO_(x)^(-)produced by the PNF system could serve as liquid nitrate nitrogen fertilizer.Overall,our work demonstrates the potential of the developed PNF system for on-site application in the production of green-leaf vegetables.

Schr?dinger药物虚拟筛选流程模块在大学生物和化学信息学教学中的应用

介绍了Schr?dinger药物虚拟筛选的基本原理和流程,结合大学生物和化学信息学课程的相关教学内容,分别描述了蛋白受体的预处理、类药性五原则、毒药物动力学(ADME)、泛筛选干扰化合物(PAINS)、高通量虚拟筛选、标准精度筛选、高精度筛选和MM/GBSA的打分排序原理和使用方法。该软件可以在大学生物和化学信息学的教学中演示,有助于提高学生对蛋白结构、分子构象、药物虚拟筛选和计算机辅助分子设计的理解,该软件有很好的图形界面,可以给学生直观的体验,大大丰富了大学课堂的教学内容。此外,该软件在药物设计领域里面也有很好的应用价值,大大节约了药物筛选的成本,提高了药物发现的效率。

Coupled dynamic model of state estimation for hypersonic glide vehicle

Aiming at handling complicated maneuvers or other unpredicted emergencies for hypersonic glide vehicle tracking,three coupled dynamic models of state estimation based on the priori information between guidance variables and aerodynamics are presented. Firstly, the aerodynamic acceleration acting on the target is analyzed to reveal the essence of the target’s motion.Then three coupled structures for modeling aerodynamic parameters are developed by different ideas: the spiral model with a harmonic oscillator, the bank model with trigonometric functions of the bank angle and the guide model with the changing rule of guidance variables. Meanwhile, the comparison discussion is concluded to show the novelty and advantage of these models.Finally, a performance assessment in different simulation cases is presented and detailed analysis is revealed. The results show that the proposed models perform excellent properties. Moreover, the guide model produces the best tracking performance and the bank model shows the second; however, the spiral model does not outperform the maneuvering reentry vehicle(MaRV) model markedly.

Destruction of PCDD/Fs by gliding arc discharges

PCDD/Fs have been become a serious issue because of their toxicological effects and associated adverse health implications. In this study, the gliding arc plasma was tested for treatment of polychlorinated dibenzo-p-dioxins （PCDDs） and polychlorinated dibenzofurans （PCDFs）, which was synthesized from pentachlorophenol in atmospheric condition at 350℃ with or without the catalysis of CuCl2. From the experiment, we found that the destruction efficiency of PCDD/F homologues after gliding was discharge ranged from 25% to 79%. This result demonstrates that gliding arc plasma is an effective technology to decompose PCDDs/Fs in flue gas. A plausible degradation mechanism for PCDD/Fs by gliding arc was discussed. Finally, a multistage reactor structure of gliding arc was proposed to upgrade removal efficiency for PCDD/Fs.

MICROSTRUCTURAL EVOLUTION AND MECHANISMS OF SUPERPLASTICITY IN LARGE GRAINED IRON ALUMINIDES

The superplastic behavior has been found in Fe 3Al and FeAl alloys with grain sizes of 100～600 μm. The large grained Fe 3Al and FeAl alloys exhibit all deformation characteristics of conventional fine grain size superplastic alloys. However, superplastic behavior was found in large grained iron aluminides without the usual prerequisites for the superplasticity of a fine grain size and grain boundary sliding. The metallographic examinations have shown that average grain size of large grained iron aluminides decreased during superplastic deformation. Transmission electron microscopy (TEM) observations have shown that there were a great number of subgrain boundaries which formed a network and among which the proportion of low and high angle boundaries increased with the increase of strain. The observed superplastic phenomenon is explained by continuous recovery and recrystallization. During superplastic deformation, an unstable subgrain network forms and these subboundaries absorb gliding dislocations and transform into low and high angle grain boundaries. A dislocation gliding and climb process accommodated by subboundary sliding, migration and rotation, allows the superplastic flow to proceed.

Numerical and Experimental Studies on the Propulsion Performance of A Wave Glide Propulsor

This paper introduces a newly developed Unmanned Wave Glide Vehicle （UWGV）, which is driven only by extracting energy from gravity waves, and presents a comprehensive study on the propulsion performance of the UWGV＇s propulsor-Wave Glide Propulsor （WGP） in a regular wave. By simplifying the WGP as six 2D tandem asynchronous flapping foils （TAFFs）, a CFD method based on Navier-Stokes equations was first used to analyze the hydrodynamic performance of TAFFs with different parameters of non-dimensional wave length rn and non-dimensional wave height n. Then, a series of hydrodynamic experiments were performed. The computational results agree well with the experimental results when n〈0.07 and both of them show the thrust force and input power of the WGP are larger at smaller m or larger n. By analyzing the flow field of TAFFs, we can see that a larger m is beneficial to the forming, merging and shredding of the TAFFs＇ vortices; as TAFFs are arranged in tandem and have the same motions, the leading edge vortex and wake vortex of the TAFFs are meaningful for improving the thrust force of their adjacent ones.