Generation of structured light beams with polarization variation along arbitrary spatial trajectories using tri-layer metasurfaces

Conventionally,the spatially structured light beams produced by metasurfaces primarily highlight the polarization modulation of the beams propagating along the optical axis or the beams'spatial transmission trajectory.In particular,along the optical axis,the polarization state is either constant or varies continuously in each output plane.Here,we develop innovative spatially structured light beams with continually changing polarization along any arbitrary spatial transmission trajectories.With tri-layer metallic metasurfaces,the geometric characteristics of each layer structure can be adjusted to modulate the phase and polarization state of the incident terahertz(THz)wave.The beam will converge to the predefined trajectory along several paths to generate a Bessel-like beam with longitudinal polarization changes.We demonstrate the versatility of the approach by designing two THz-band structured light beams with varying polarization states along the spatial helical transmission trajectory.Continuous linear polarization changes and linear polarization to right circular polarization(RCP)and back to linear polarization changes are realized respectively.The experimental results are basically consistent with the simulated results.Our proposal for arbitrary trajectory structured light beams with longitudinally varying polarization offers a practical method for continuously regulating the characteristics of spatial structured light beams with non-axial transmission.This technique has potential uses in optical encryption,particle manipulation,and biomedical imaging.

The Technique of the Tri-Layer Coating: An Effective Solution for the Protection of Earthen Constructions

The problem with earth constructions is their low resistance to water. Step by step, the water degrades the exterior facings of the structures and ends up creating zones of weakness through the structures, making them collapse and creating enormous socio-economic problems, especially in rural areas. The solutions proposed to date, like the use of straw, cow dung, boiled skins, banana leaves, tar, cement soil, have shown their limits. Generally, the poor adhesion between the protected material and the protective layer means that the latter always ends up peeling off. This work, which is inspired by the traditional practice where plant tannins are used to brush the earthen walls to waterproof them, proposes a tri-layer coating composed of soil, powder and hydrolysable tannins extracted from the stem bark of Bridelia. This work focuses on the geotechnical characterization of the soil, the extraction of hydrolysable tannin, the manufacture of the micro-coating, the resistance tests carried out on the micro-coating, the technique of implementation and the test of evaluation of the performance of the tri-layer coating. The results obtained show that not only does the tri-layer coating adhere perfectly to the layer to protect, but it also waterproofs it and protects it against shocks.

Can semipermeable membranes coating materials influence in vivo performance for paliperidone tri-layer ascending release osmotic pump tablet:In vitro evaluation and in vivo pharmacokinetics study

One purpose of this study was to develop a paliperidone(PAL)tri-layer ascending release pushepull osmotic pump(TA-PPOP)tablet which could meet the needs of clinical applications.And another purpose was to investigate whether different coating materials influenced in vivo performance of TA-PPOP.The ascending release mechanism of this trilayer delivery system on theory was elaborated.TA-PPOP was prepared by means of coating with cellulose acetate(CA)or ethyl cellulose(EC).Several important influence factors such as different core tablet compositions and different coating solution ingredients involved in the formulation procedure were investigated.The optimization of formulation and process was conducted by comparing different in vitro release behaviors of PAL.In vitro dissolution studies indicated that both the two formulations of different coating materials were able to deliver PAL at an ascending release rate during the whole 24 h test.The in vivo pharmacokinetics study showed that both self-made PPOP tablets with different coating had a good in vitro-in vivo correlation(IVIVC)and were bioequivalent with the brand product,which demonstrated no significant influence of the coating materials on the in vivo release acceleration of TA-PPOP.

Deposition and Magnetic Properties of Fe_3O_4/Fe/Fe_3O_4 Tri-layer Films

The Fe_3O_4/Fe/Fe_3O_4 (MIM) tri-layer films (200 nm/12-93 nm/200 um) were prepared on Si(100) by DC-magnetron reactive-sputtering followed by air- or vacuum-annealing at 280-400℃ for 1.5 h, respectively. Magnetic properties and phases under different sandwich and annealing conditions were studied. In MIM structure, the incorporation of the interlayer iron does increase the magnetization measured under 8 kOe (M_8K), but reduce coercivity (H_c). The H_c of asdeposited films decreases from 354 Oe to 74 Oe; while M_8K increases from 254 to 392 emu/cc. By annealing in air, the whole MIM tri-layer film becomes γ-F_e2O_3, H_c is about 550 O_e and M_8K is around 250 emu/cc. The coercivity mechanism of as-deposited and annealed MIM trilayer films belongs to domain-wall pinning type. δM plots show that when the interlayer Fe thickness is 12 um, the Fe and Fe_3O_4 layers are decoupled in the as-deposited and annealed states; while it is coupled in the as deposited state when the Fe thickness increases to 23 um. Vacuum annealing of the MIM films leads to increase in both coercivity and magnetization, and to enhance the exchange coupling between layers.

GIANT MAGNETO-IMPEDANCE OF PATTERNED FeSiB/Cu/FeSiB TRI-LAYER FILMS

Sensitive magnetic field sensor with good performances can be fabricated utilizing the giant magneto-impedance (GMI) effect of soft magnetic multi-layer thin films. The transverse and longitudinal GMI effect in patterned FeSiB/Cu/FeSiB tri-layer films with the change of external magnetic field and frequency were studied at the same time. The change of the impedance of the films with the external magnetic fieldand frequency was shown. Comparing the longitudinal and transverse effect, the transverse effect has a larger linear range from zero magnetic field to a quite large magnetic field at all frequencies, and the change still were not saturated until the external magnetic field reached 1.2×104A/m, which illustrated that the films can be utilized to detect larger magnetic fields than now presented GMI sensors.

Corrosion behavior and failure mechanism of SiC whisker and c-AlPO_(4) particle-modified novel tri-layer Yb_(2)Si_(2)O_(7)/mullite/SiC coating in burner rig tests

The corrosion behavior of environmental barrier coatings(EBCs)directly affects the service life and stability of ceramic matrix composite(CMC)structural parts in the aero-engines.The silicon carbide(SiC)whisker toughening phase and c-AlPO_(4) bonding phase are firstly used to improve the service life of novel tri-layer Yb_(2)Si_(2)O_(7)/mullite/SiC EBCs in the burner rig test.The formation of penetrating cracks in Yb_(2)Si_(2)O_(7)/mullite/SiC coating caused the failure of coating at 1673 K.The SiC whiskers in mullite middle coating significantly inhibited the formation of penetrating cracks in Yb_(2)Si_(2)O_(7)/mullite/SiC coating,and efficiently prevented the oxidation of carbon fiber reinforced silicon carbide(C_(f)/SiC)samples for 360-min thermal cycles(24 times)with a weight loss of 6.19×10^(−3) g·cm^(−2).Although c-AlPO_(4) particles further improved the service life of SiC_(w)-mullite(SM)coating,the overflow of PO_(x) gas aggravated the formation and expansion of cracks in the Yb_(2)Si_(2)O_(7) outer coating,and caused the service life of overall Yb_(2)Si_(2)O_(7)/c-AlPO_(4)-SiC_(w)-mullite(ASM)/SiC coating to be slightly lower than that of Yb_(2)Si_(2)O_(7)/SM/SiC coating.This study guides the design of modified tri-layer EBCs with long service life in high-temperature and high-speed gas environment.

PREPARATION OF SILICA/POLY(METHACRYLIC ACID)/POLY(DIVINYLBENZENE-CO-METHACRYLIC ACID) TRI-LAYER MICROSPHERES AND THE CORRESPONDING HOLLOW POLYMER MICROSPHERES WITH MOVABLE SILICA CORE

Hollow poly（divinylbenzene-co-methacrylic acid） （P（DVB-co-MAA）） microspheres were prepared by the selective dissolution of the non-crosslinked poly（methacrylic acid） （PMAA） mid-layer in ethanol from the corresponding silica/PMAA/P（DVB-co-MAA） tri-layer hybrid microspheres, which were afforded by a three-stage reaction. Silica/PMAA core-shell hybrid microspheres were prepared by the second-stage distillation polymerization of methacrylic acid （MAA） via the capture of the oligomers and monomers with the aid of the vinyl groups on the surface of 3-（methacryloxy）propyl trimethoxysilane （MPS）-modified silica core, which was prepared by the Stober hydrolysis as the first stage reaction. The tri-layer hybrid microspheres were synthesized by the third-stage distillation precipitation copolymerization of functional MAA monomer and divinylbenzene （DVB） crosslinker in presence of silica/PMAA particles as seeds, in which the efficient hydrogen-bonding interaction between the carboxylic acid groups played as a driving force for the construction of monodisperse hybrid microspheres with tri-layer structure. The morphology and the structure of silica core, silica/PMAA core-shell particles, the tri-layer hybrid microspheres and the corresponding hollow polymer microspheres with movable silica cores were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy （XPS）.

Thermal Flexure Measurement and Inverse Characterization for a Tri-layer Thin Plate

The paper presents a new study on a tri-layer thin plate.Shadow moiré implemented with an advanced phase unwrapping technique is employed to obtain actual flexural deformation of a real-life plate sample subjected to thermal loads.An analytical model is re-formulated to provide the plate with global closed-form solutions of the plate deflection as well as the interfacial stress and strain.With the measurements and the solutions available,an inverse iterative approach is developed to evaluate and maximize the correlation between the measured and the predicted thermal flexure,leading to ascertained materials' constitutive and thermal behaviour.The inverse search algorithm starts with estimated ranges of material property parameters and progressively updates them to finally approach the respective true values.The established model solutions along with the optimized material properties matrix enable an accurate evaluation of the interfacial stresses/strains for the specific plate sample.

三层复合铝板固-液-固铸轧复合工艺变形特性及层厚比调控

本文以三层复合铝板固-液-固铸轧复合工艺作为研究对象,基于MSC.Marc生死单元法建立了二维热-力耦合模型并通过实验验证模型的可靠性;依据该模型获得铸轧区组元金属的变形特性及层厚比随工艺参数变化规律,并构建层厚比预测模型。结果表明:覆层在KISS点附近开始发生塑性变形,变形程度取决于KISS点高度。覆层厚度、铸轧速度对覆层层厚比的影响最为明显。基于该模型构建的层厚比预测模型具有较高的准确性,其最大相对误差仅为2.77%。最后,根据该预测模型,提出层厚比调控策略,即应先确定覆层厚度,随后匹配铸轧速度,最后调整浇铸温度与预热温度。

电力市场全景实验平台三层实验体系及其运行模式

为支撑电力市场多样化仿真需求,对电力市场全景实验平台进行了功能架构升级,提出了实验平台-实验场景-实验算例的三层实验体系。将电力市场全商品序列覆盖的全景实验平台进行功能拆解,经独立化封装后形成实验平台功能组件库。根据仿真目标要求,灵活性选取组件元素搭建电力市场实验场景,并针对每个场景进行模型数据配置,形成仿真算例。通过场景的伸缩和场景间的联合,三层实验体系可在支撑全景实验需求的基础上,提升功能调整和平台使用的效率。最后,进一步提出了电力市场全景实验平台双专家体系运行方式,并具体设计了4种电力市场典型实验场景。

复杂背景下改进的红外弱小目标检测

许多研究者关注红外弱小目标检测领域并进行过种种探索,然而复杂背景下检测的难题始终未得到满意的解决。复杂背景下的杂波难以消除,目标检测无法得到显著结果。为此,提出了一种基于高升压滤波器的加权三层窗口目标检测算法(high-boost weighted tri-layer local contrast measure,HB-WTLLCM),针对复杂背景的目标检测进行目标增强,从而提高检测率。本文算法首先利用改进的高升压滤波器对红外原始图像进行预处理,再利用三层嵌套窗口,根据目标形状进行局部对比度增强。最后引入一种基于复杂度评估的加权算法,进一步进行目标增强和随机噪声抑制。实验数据显示,本文提出的算法相比于主流算法在多建筑、多树木的复杂背景下目标增强能力更强,检测率更高。上述结果提示,本文提出的HB-WTLLCM算法对于复杂场景下红外弱小目标进行检测具有一定优势。

用三层胶工艺X射线光刻制作T型栅

采用三层胶工艺 X射线光刻制作 T型栅 ,一次曝光 ,分步显影 ,基本解决了不同胶层间互融的问题 .该方法制作效率高 ,所制作的 T型栅形貌好 ,头脚比例可控 ,基本满足器件制作要求 .

梯度Cu-CeO_2-Ni-YSZ复合阳极直接甲烷SOFC的制备与性能

采用三层共压-共烧结法,并涂覆La0.8Sr0.2MnO3(LSM)阴极,制备了梯度Ni-YSZ阳极结构的固体氧化物燃料电池(SOFC)(大孔Ni-YSZ∣微孔Ni-YSZ∣YSZ∣LSM)(YSZ:Y2O3稳定的ZrO2;LSM:Sr掺杂的LaMnO3).通过浸渍法在大孔Ni-YSZ基底中沉积占总重量约1%的Cu-CeO2抗积碳催化剂,形成梯度Cu-CeO2-Ni-YSZ复合阳极.分别以CH4和H2为燃料,空气为氧化剂,测定了构造的SOFC输出电性能和长期稳定性.结果表明,三层共压-共烧结法制备的梯度阳极SOFC,层间结合紧密无缺陷,阳极梯度孔结构明显,YSZ膜致密无缺陷.在850°C下操作,以梯度Ni-YSZ阳极制备的SOFC,燃料由H2切换为甲烷时,最大功率密度由284mW·cm-2下降到143mW·cm-2;而以Cu-CeO2-Ni-YSZ复合阳极构造的SOFC出现相反趋势,H2切换为甲烷后最大输出由176mW·cm-2增加到196mW·cm-2.在250mA·cm-2负荷下,梯度Ni-YSZ阳极支撑的直接甲烷SOFC仅稳定运转10h便出现明显衰减,阳极中积碳严重;但Cu-CeO2-Ni-YSZ复合阳极支撑SOFC连续运转50h,输出电压与输出功率密度基本不变,电镜观察不到积碳.

基于B/S与三层C/S混合模式的MIS构建

随着计算机及网络技术的飞速发展,企业为了提高效率、规范日常管理构建信息系统已成必然.以疗养院系统为背景,介绍了基于Web的B/S与基于分布式结构的三层C/S混合模式的管理信息系统(MIS)设计与实现方案,并从功能结构、体系结构及安全性等方面对系统进行了论述.系统采用SQL Server 2000作为后台数据库管理系统,采用PB 8.0结合HTML语言及ASP等技术实现前台界面的开发.完成的疗养院管理信息系统具有实用价值.

90nm T型栅工艺在高频GaAs PHEMT MMIC中的应用

采用PMMA/P（MMA-MAA）/PMMA三层胶结构,通过优化电子束直写电压、束流和显影等工艺参数,得到了理想的光刻胶形貌。利用干法刻蚀和湿法腐蚀相结合的方法实现了双凹槽栅结构。通过优化蒸发功率、蒸发时间及各层金属厚度,解决了栅掉帽的问题。开发了90 nm自对准双凹槽T型栅电子束三层胶光刻工艺技术。应用90 nmT型栅工艺制作了W波段GaAs PHEMT功率放大器及V波段Ga As PHEMT低噪声放大器。测试结果表明,在频率为90~96 GHz、源漏电压5 V、栅源电压-0.3 V、输入功率13 dBm时,功率放大器电路输出功率为20.8 dBm,功率增益为7.8 dB;在频率为57~64 GHz、源漏电压2.5 V、漏极电流55 m A时,低噪声放大器增益大于24 dB,带内噪声系数小于3.5 dB,验证了该工艺技术的可行性和可应用性。

电工测量三层次实验教学体系的构建与实践

实践性环节教学在培养高素质创新人才中的作用日益为人们所重视,本文从独立设课的角度对电工测量三层次实验教学体系的设计思想、教学内容的构成以及具体的组织实施和实践效果进行了阐述。

砂煤互层水力裂缝穿层扩展机理

临兴地区含煤岩系地层纵向互层发育煤层、致密砂岩层产层组,当砂煤薄层组合开发时,受界面胶结性质、地应力差、压裂选层、煤层厚度、施工参数等因素的影响,难以判断裂缝是否垂向穿层。为了分析砂煤互层水力压裂裂缝穿层扩展规律,通过选取砂煤天然露头岩样进行交错组合,利用大尺寸真三轴水力压裂系统开展了砂煤产层组组合的物理模拟实验,研究了压裂选层、层间胶结强度、煤层厚度、胶液和活性水对水力裂缝穿层扩展的影响。实验结果表明:在煤岩中起裂时,受煤岩层理和自身天然裂缝的影响,裂缝在扩展过程中,容易发生转向,使得裂缝形态复杂多样,不利于裂缝穿层;在砂岩层中起裂时,砂岩中水力裂缝形态简单,形成水力主缝,容易穿层扩展;当界面胶结强度较弱时,裂缝扩展至砂煤界面,容易发生转向,沿界面扩展,形成水平裂缝;煤层越厚越容易耗散水力能量,使得水力裂缝难以穿层扩展;胶液的造缝能力优于活性水,但其对储层伤害较重,压裂液类型的选取需根据现场压裂所需进行甄选。

多层客户/服务器结构下的网络计算技术

通过对传统的两层客户 /服务器结构与三层客户 /服务器结构的工作原理与机制的分析比较 ,阐述了多层客户 /服务器结构的特点 ,揭示了传统的两层客户 /服务器结构的弊端以及三层客户 /服务器结构的优点 .同时还给出了如何实现多层客户 /服务器结构的一种有效的方法 ,分析了实现多层客户 /服务器结构的关键所在 .

一种受人脑三阶段记忆机制启发的鲁棒运动目标跟踪方法

目前大多数运动目标跟踪算法在目标姿态发生突变或目标被严重遮挡后会产生目标丢失现象,为解决此类问题,受人脑三阶段记忆信息处理机制的启发,本文提出一种三层旋转圆记忆模型(Spinning Tri-Layer-Circle Memory Modeling,STLC-MM)用于在目标跟踪过程中对目标模板进行更新.模型定义了三个旋转圆记忆空间用于存储和处理跟踪过程中用过的目标模板.三个圆记忆空间旋转时,记忆空间中的模板也随之以相同的速度旋转,同时模型通过模拟一些人类的认知行为,如,记忆、提取、遗忘等对模板进行更新.最后,为了验证所提方法有效性,本文将STLC-MM嵌入到粒子滤波目标跟踪框架进行目标跟踪实验.实验结果表明所提方法在目标姿态突变以及严重遮挡等方面具有较强的鲁棒性.

利用RELACS辅助技术制作“T”型栅

利用RELACS化学收缩辅助技术制作了i线三层胶结构的"T"型栅。首先利用水溶性的化学收缩试剂RELACS,涂在曝光完成的光刻图形上,然后借由混合烘焙让光刻胶中的光酸分子因受热而产生扩散运动并进入到RELACS试剂内,催化RELACS试剂,让RELACS试剂中的高分子与交链分子产生交链反应,使得光刻胶表面形成新的一层不溶于水的交链层而达到光刻图形收缩的目的。此方法增加了细栅光刻的宽容度,降低了细栅光刻制作的难度,极易将0.5μm的栅条收缩到0.3μm,甚至更小,不但有效地减小了栅长,而且提高了细栅光刻的成品率。RELACS技术可以应用于不同光刻胶类型的"T"型栅制作中。