Equivalent oxide thickness scaling of Al_2O_3/Ge metal-oxide-semiconductor capacitors with ozone post oxidation

Aluminum-oxide films deposited as gate dielectrics on germanium （Ge） by atomic layer deposition were post oxidized in an ozone atmosphere. No additional interfacial layer was electron microscopy and X-ray photoelectron spectroscopy detected by the high-resolution cross-sectional transmission measurements made after the ozone post oxidation （OPO） treatment. Decreases in the equivalent oxide thickness of the OPO-treated Al2O3/Ge MOS capacitors were confirmed. Furthermore, a continuous decrease in the gate leakage current was achieved with increasing OPO treatment time. The results can be attributed to the film quality having been improved by the OPO treatment.

Prediction of Apparent Equivalent Thickness Using the Spontaneous Potential Method and Its Application to Oilfield Development

The upper spontaneous potential produced by oil and gas accumulation is of a stable potential field, and its intensity is directly proportional to the content of the source and inversely proportional to the radius apart from the source. Theoretical research and practical results show that anomalies of spontaneous potential can indicate oil-bearing sandstone bodies and locate the areas of oil and gas accumulation. In oil areas which have fewer reservoir beds, the petroleum reservoir thickness can be predicted by determining the linear relationship between potential intensity and apparent equivalent thickness. In the Weixing （卫星） oilfield, which is devoid of sufficient reservoir beds, its apparent equivalent thickness can be predicted by the linear equation h= -0.19x＋0.74. On the basis of geological research, we use the spontaneous potential method to predict the equivalent thickness, helping in the selection of the most appropriate drill sites to enhance the probability of successful well boring so as to serve the next round development of the oilfield.

Science Letters: Equivalent thickness of materials of fused silica and stainless steel in the flow of microtubes

The deviation of flow characteristics from the predictions of the conventional theory for microtubes was attrib- uted to the change of fluid viscosity resulted from the interactions between the molecules on solid wall and in fluid. The degree of this departure is dependent on the microtubes materials. A concept of equivalent thickness with which conventional theory can be used to predict the flow in microtubes without modifying the fluid viscosity was put forward. The values of equivalent thickness for fused silica and stainless steel materials were determined as 1.8 μm and 1.5 μm, respectively, by repeated numeri- cal simulation.

Retrieving chlorophyll content and equivalent water thickness of Moso bamboo(Phyllostachys pubescens) forests under Pantana phyllostachysae Chao-induced stress from Sentinel-2A/B images in a multiple LUTs-based PROSAIL framework

Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT with SAIL(PROSAIL)radiative transfer model is widely used for vegetation biochemical component content inversion.However,the presence of leaf-eating pests,such as Pantana phyllostachysae Chao(PPC),weakens the performance of the model for estimating biochemical components of Moso bamboo and thus must be considered.Therefore,this study considered pest-induced stress signals associated with Sentinel-2A/B images and field data and established multiple sets of biochemical canopy reflectance look-up tables(LUTs)based on the PROSAIL framework by setting different parameter ranges according to infestation levels.Quantitative inversions of leaf area index(LAI),leaf chlorophyll content(LCC),and leaf equivalent water thickness(LEWT)were derived.The scale conversions from LCC to canopy chlorophyll content(CCC)and LEWT to canopy equivalent water thickness(CEWT)were calculated.The results showed that LAI,CCC,and CEWT were inversely related with PPC-induced stress.When applying multiple LUTs,the p-values were<0.01;the R2 values for LAI,CCC,and CEWT were 0.71,0.68,and 0.65 with root mean square error(RMSE)(normalized RMSE,NRMSE)values of 0.38(0.16),17.56μg cm-2(0.20),and 0.02 cm(0.51),respectively.Compared to the values obtained for the traditional PROSAIL model,for October,R2 values increased by 0.05 and 0.10 and NRMSE decreased by 0.09 and 0.02 for CCC and CEWT,respectively and RMSE decreased by 0.35μg cm-2 for CCC.The feasibility of the inverse strategy for integrating pest-induced stress factors into the PROSAIL model,while establishing multiple LUTs under different pest-induced damage levels,was successfully demonstrated and can potentially enhance future vegetation parameter inversion and monitoring of bamboo forest health and ecosystems.

Nonlinear phase error analysis of equivalent thickness in a white-light spectral interferometer

A white light spectral interferometry based on a Linnik type system was established to accurately measure the thin film thickness through transparent medium.In practical work,the equivalent thickness of a beam splitter and the mismatch of the objective lens introduce nonlinear phase errors.Adding a transparent medium also increases the equivalent thickness.The simulation results showthat the equivalent thickness has a significant effect on thin film thickness measurements.Therefore,it is necessary to perform wavelength correction to provide a constant equivalent thickness for beamsplitters.In the experiments,some pieces of cover glasses as the transparent medium were added to the measured beam and then a standard thin film thickness of 1052.2±0.9 nm was tested through the transparent medium.The results demonstrate that our system has a nanometer-level accuracy for thin film thickness measurement through transparent medium with optical path compensation.

Analytic Computation Method of the Equivalent Thickness of Superposition Multi-Throttle-Slices of Twin-Tubes Shock Absorber

By elastic mechanics, the deformation of single throttle-slice for shock absorber was analyzed, the formula of its deformation was established. According to the relation of the deformation of multi-throttle-slices with the pressure on each slice, the analytic formula of equivalent thickness of multi-throttle-slices was established. Followed is a practical example for the computation of the equivalent thickness of multi-throttle-slices, compared the computed results with that simulated by ANSYS. The results show that the computation method of equivalent thickness of multi-throttle-slices is accurate enough.

Rock burst risk evaluation based on equivalent surrounding rock strength

On-site investigations consistently show that the rock burst inherent to coal seams varies greatly with coal seam thickness.In this study,impact factors related to coal seam thickness and surrounding rock strength were analyzed and a corresponding rock burst risk assessment method was constructed.The model reflects the influence of coal seam thickness on the stress distribution of surrounding rock at the roadway.Based on the roadway excavation range,a stress distribution model of surrounding roadway rock is established and the influence of coal seam thickness on rock burst risk is analyzed accordingly.The proposed rock burst risk assessment method is based on the equivalent surrounding rock strength and coal seam bursting liability.The proposed method was tested in a 3500 mining area to find that it yields rock burst risk assessment results as per coal seam thickness that are in accordance with real-world conditions.The results presented here suggest that coal seam thickness is a crucial factor in effective rock burst risk assessment.

Neutron distribution and yield produced by 50 MeV/u^(18)O-ion on thick targets

Neutron energy, fluence rate, angular distributions and dose equivalent rate distributions around the thick Be, Cu, An targets bombarded by 50 MeV/u 18O-ion were measured using a threshold detector activation method. At the same time,the neutron yields of 18O-ion and the neutron emission rates in the forward direction were obtained approximately.

极端生态环境水循环关键参量监测技术研究现状与进展

针对高寒和干旱极端生态环境水循环变化对国家生态安全的重要性,需要开展水循环关键参量监测设备与技术研究。本文重点围绕水循环关键参量野外原位/移动/非接触式、自动、稳定监测等技术难点,开展了一系列监测生态系统水-土-气-冰-雪的关键参量的新技术设备研究。通过构建基于物联网的天地一体化生态系统监测体系,打破行业技术壁垒,促进工程技术、地质学、计算机科学等不同领域的跨学科合作,共同开展极端生态环境水循环关键参量监测技术研究与创新,并将实现对重要生态功能区的大范围、全天候、立体化监测,对推进我国生态文明建设具有重要支撑作用,促进并实现我国生态监测技术的综合应用和发展。

三种干预方法对隐匿性近视儿童相关眼部生物学参数的影响

目的:观察三种不同干预方法对隐匿性近视儿童相关眼部生物学参数的影响,探究其对隐匿性近视儿童的不同控制作用。方法:前瞻性队列同期对照试验研究。选取2021-12/2022-05在承德医学院附属医院眼科门诊初次诊断为隐匿性近视且未经过任何相应近视控制训练的患儿60例120眼。随机分为3组,A组20例40眼给予0.01%阿托品滴眼液,B组20例40眼接受翻转拍视力训练,C组20例40眼给予七叶洋地黄双苷滴眼液。随访12 mo,观察三组患儿初诊,干预后6、12 mo时等效球镜度数(SE)、眼轴长度(AL)、角膜曲率(CC)、调节灵敏度(AF)、黄斑区视网膜厚度的变化情况。结果:干预后6、12 mo,三组患儿AL、SE和AF较初诊有差异(均P<0.05),干预后6 mo与12 mo比较均有差异(均P<0.05),B组和C组SE和AF均高于A组(均P<0.05),干预前后CC比较无差异(均P>0.05)。三组患儿干预后6、12 mo外环颞侧、鼻侧、下方、黄斑中心凹视网膜厚度与初诊比较均有差异(均P<0.05),干预后6 mo与12 mo比较均有差异(均P<0.05)。三组患儿干预前后其余黄斑区视网膜厚度比较均无差异(均P>0.05)。结论:0.01%阿托品滴眼液防控近视作用优于翻转拍视力训练及七叶洋地黄双苷滴眼液。应用0.01%阿托品滴眼液及接受翻转拍训练可延缓隐匿性近视的进展。

基于水分光谱指数的烟草叶片等效水厚度估测

为及时、准确监测烟草叶片的水分状况,连续2年开展不同基因型烤烟品种的水分胁迫试验,测定烟叶的光谱反射率和叶片等效水厚度(EWT),系统分析350~2500 nm波段范围内任意2个波段组合而成的比值水分指数(SRWI)和归一化水分指数(NDWI),并构建烟草EWT的光谱指数预测模型。结果表明:(1)不同基因型烟草的叶片等效水厚度均随灌水量的减少而降低。(2)不同水分处理的烟叶光谱反射率在可见光波段和近红外波段均发生了规律性变化。(3)筛选出的烟草叶片等效水厚度的光谱敏感波段主要集中在可见光区域的500~600 nm、近红外区域的700~900和1000~1250 nm、短波红外区域的1900~2000 nm,最佳水分光谱指数分别为NDWI(R1920,R1930)、SRWI(R1930,R1920),核心波段为1920、1930 nm。(4)利用水分光谱指数构建的烟草叶片等效水厚度的线性和非线性预测模型,以极限学习机模型(ELM)的精准度和稳定性最佳(P-R2=0.853**,T-R2=0.855**,RMSE=0.004)。表明可利用水分光谱指数NDWI(R1920,R1930)、SRWI(R1930,R1920)结合机器学习模型实现烟草叶片含水量的精准监测。

双层金属板材同速异径蛇形轧制复合变形研究

采用ANSYS Multiphysics/LS-DYNA软件对Q345碳钢/NM400耐磨钢复合板轧制复合过程进行了有限元模拟,并开展蛇形轧制实验,验证了所建立有限元模型的准确性。总结了轧辊直径、错位量、摩擦条件和压下量对复合板变形行为的影响,结果表明,其他工艺参数不变条件下,初始辊径和摩擦条件对复合板平直度的影响较大,初始辊径越大和摩擦系数越小,复合板越平直;错位量和压下量对复合板结合面处等效塑性应变的影响较大,错位量适当增大,压下量越大,复合板结合面处变形更充分;轧辊直径对复合板厚度比影响较大,轧辊直径越大,复合板层厚比越大。其中蛇形轧制错位量的调整可同时实现对板材厚度比、等效塑性应变和弯曲曲率的正向调控,证明了可以通过调整蛇形轧制的错位量获得形性兼优的金属复合板。

建筑用隔汽材料水蒸气透过性能检测技术研究

介绍了建筑用隔汽材料水蒸气当量空气层厚度Sd的检测现状,并对称重法、红外法和电解法进行了对比分析。针对采用称重法检测建筑用隔汽材料水蒸气透过性能的情况,从理论计算、测试精度、结果稳定性、实际操作可行性等方面进行了详细的论证;总结了3种不同检测方法的测试范围及各自的特性。提出了建筑用隔汽材料使用称重法测试水蒸气透过性能的可行性解决方法,即只测试1个称重周期,既可以缩短测试周期,又可以减少干扰因素的影响,且数据稳定性好,也更能代表材料的真实阻湿性能。

耐张塔输电线路等值覆冰厚度的简化预测方法

输电线路覆冰会引发断线倒塔事故,严重影响电网的安全运行,准确监测线路覆冰情况具有重要的工程意义和应用价值。在输电线路综合荷载的静力学模型基础上,提出了两种简化的等值覆冰厚度预测方法。第一种简化方法不需要水平档距和高度差参数,减少了输入参数;第二种简化方法不需要角度传感器,避免角度传感器误差造成的预测性能下降,且减小了系统的硬件成本。结果表明:在大水平档距情况下,第一种简化方法与现有方法的预测性能基本一致;在覆冰前后悬垂角变化不大的情况下,第二种简化方法的预测误差在工程允许范围以内。

减振器叠加节流阀片的研究

为了探究减振器叠加阀片等效厚度、设计方法及其对减振器特性的影响,对节流阀片在阀口位置的弯曲变形量和叠加阀片等效厚度进行了研究,给出了等效厚度计算公式.对叠加阀片的应力进行了分析,对阀片应力和厚度之间的关系及叠加阀片最大厚度的设计进行了探讨.通过实例对叠加阀片进行了设计和验证,并进行了阻力特性试验.试验表明,叠加阀片厚度设计、等效厚度计算和应力分析方法是准确的和有效的.

叶片辐射等效水厚度计算与叶片水分定量反演研究

在分析叶片水分对叶片反射率光谱影响的基础上,结合叶片内部水、干物质、叶绿素等光谱吸收系数曲线特征,分析了975nm波长水气吸收特征处叶片与光线相互作用原理,并利用Beer定律和945nm,975nm波长光谱反射率差值,推导了975nm波长辐射等效水厚度REWT的计算公式。由于表面反射、杂散射光、非均匀介质和叶片内部多次散射等因素,光在叶片内部的辐射传输不能直接用Beer定律描述,且利用Beer定律计算的REWT与叶片等效水水厚度EWT之间会有较大的偏差。论文设计和获取了多植物、不同水分梯度的叶片光谱获取试验数据,整理和分析了欧盟Lopex93数据,利用这两组独立数据和论文提出的REWT计算公式,比对验证了975nm波长叶片REWT和叶片EWT的统计模型,结果表明:由于光在叶片内部的多次散射,REWT是EWT的3.3倍左右。论文研究结果一方面为叶片EWT定量遥感探测提供了一种快速、简单且有较强通用性的计算方法和模型,另一方面,探测叶片REWT和EWT的定量关系,有助于了解叶片内部的光辐射传输情况,特别是间接了解近红外波段叶片内部的多次散射情况。

保水开采覆岩等效阻水厚度的内涵、算法与应用

煤炭资源保水开采是实现绿色化开采的核心技术之一,保水开采可行性评价则是开展科学开采设计的基础问题。从采动覆岩整体阻水性角度入手,综合考虑覆岩整体的阻水行为与地下水系统的动态响应之间的关系,提出了将上覆隔水岩层(组)虚拟为等效阻水层的学术思想,形成了基于采动覆岩等效渗透系数计算等效阻水厚度进行保水采煤可行性定量评价的新思路与方法。基于达西定律、Kozeny-Caman方程以及采动覆岩移动影响函数递推关系,采用分层、分区组合等效方法,在单岩层水平方向上通过并联来计算整层垂向等效渗透系数,进而通过垂直方向上进行多岩层等效渗透系数串联计算,建立了基于采高、工作面长度、沉陷参数和岩层初始水理参数的采动覆岩整体垂向等效渗透系数的计算方法;以采后覆岩地下水渗漏速度与目标含水层补给速度相等作为保水采煤临界条件,确定了保水采煤最大临界渗透系数与采高、等效岩层厚度之间的关系;基于采动覆岩的渗透系数与其等效阻水厚度成反比的假设,建立了采动覆岩等效阻水厚度的计算方法,进而根据维持含水层水位稳定所允许的最大临界渗透系数,提出了基于采动覆岩等效阻水厚度的保水采煤可行性评价方法,并通过伊犁四矿保水采煤含水层水位变化实测进行了实例验证。研究成果为保水开采预测评价、方法选择和参数优化提供了新的方法。

反演磁性地层界面的逐步剥离磁场法

在对前人研究方法总结对比的基础上,本文提出了一种逐步剥离位场反演磁性地层界面的方法,该方法假定位场是由一个等效单位厚度层的等效磁化强度变化引起,通过逐步剥离位场,得到等效单位厚度层的等效磁化强度,进而求取磁性地层的起伏.本文进行了理论模型计算和野外实例处理,取得了良好效果.

胶厚对单搭粘接接头强度影响的试验与仿真研究

为研究不同胶层厚度对单搭粘接接头强度的影响,对胶层厚度为0.2 mm、0.7 mm、1.5 mm和2.5 mm的铝5052-铝5052(Al5052-Al5052)单搭粘接接头进行拉伸-剪切试验,对比不同胶厚对Al5052-Al5052单搭粘接接头强度的影响。仿真分析考虑材料非线性和几何非线性,模拟不同胶层厚度表面上的等效应力的分布情况,研究结果表明:胶层厚度影响粘接剂对Al5052-Al5052单搭粘接接头的粘接效果,胶层表面的von Mises应力随着胶层厚度的增加而增大,Al5052-Al5052单搭粘接接头的强度随着胶层厚度的增加而降低。

应用Lenstar 900测量不同程度轴性近视生物参数分析

目的：采用眼光学生物测量仪（ Lenstar 900）测量轴性近视眼部生物参数,并分析参数间的关系。 方法：将近视患者413例826眼按照等效球镜度数进行分为3组：低度近视（〈3.00D,104眼）,中度近视（3.00~6.00D,500眼）,重度近视（〉6.00D,222眼）,采用Lenstar 900对所有眼进行检测,得到角膜中央厚度（ CCT ）、前房深度（ AD）、晶状体厚度（ LT）、眼轴长度（ AL）等参数。各组参数进行方差分析,等效球镜、AL,LT之间相关分析。结果：不同程度轴性近视患者AL（F=206.16,P〈0.01）、AD（F=4.764,P〈0.05）存在差异性,而CCT、LT这两项参数无差异性。 Person相关分析等效球镜（ SE）度数与AL（ r=0.662, P〈0.01）、AD（r=0.095,P〈0.05）呈正相关,与CCT,LT无相关性。 AL与AD（r=0.347, P〈0.01）、CCT（r=0.126, P〈0.01）呈正相关,与LT呈负相关（r=-0.265,P〈0.01）。 LT与AD呈负相关（r=-0.496,P〈0.01）。 结论：近视程度越深, AL 和 AD 越大。等效球镜度数与AD呈正相关。 AL与等效球镜度数、AD、CCT正相关,与LT负相关性。 LT与AD呈负相关。