Similarities and differences in inherent mechanism and characteristic frequency between the one-dimensional poroelastic model and the layered White model

The similarities and differences in inherent mechanism and characteristic frequency between the onedimensional(1D)poroelastic model and the layered White model were investigated.This investigation was conducted under the assumption that the rock was homogenous and isotropic at the mesoscopic scale.For the inherent mechanism,both models resulted from quasi-static flow in a slow P-wave diffusion mode,and the differences between them originated from saturated fluids and boundary conditions.On the other hand,for the characteristic frequencies of the models,the characteristic frequency of the 1D poroelastic model was first modified because the elastic constant and formula for calculating it were misused and then compared to that of the layered White model.Both of them moved towards higher frequencies with increasing permeability and decreasing viscosity and diffusion length.The differences between them were due to the diffusion length.The diffusion length for the 1D poroelastic model was determined by the sample length,whereas that for the layered White model was determined by the length of the representative elementary volume(REV).Subsequently,a numerical example was presented to demonstrate the similarities and differences between the models.Finally,published experimental data were interpreted using the 1D poroelastic model combined with the Cole-Cole model.The prediction of the combined model was in good agreement with the experimental data,thereby validating the effectiveness of the 1D poroelastic model.Furthermore,the modified characteristic frequency in our study was much closer to the experimental data than the previous prediction,validating the effectiveness of our modification of the characteristic frequency of the 1D poroelastic model.The investigation provided insight into the internal relationship between wave-induced fluid flow(WIFF)models at macroscopic and mesoscopic scales and can aid in a better understanding of the elastic modulus dispersion and attenuation caused by the WIFF at different scales.

Enhancement of Frster energy transfer from thermally activated delayed fluorophores layer to ultrathin phosphor layer for high color stability in non-doped hybrid white organic light-emitting devices

Fluorescence/phosphorescence hybrid white organic light-emitting devices（WOLEDs） based on double emitting layers（EMLs） with high color stability are fabricated.The simplified EMLs consist of a non-doped blue thermally activated delayed fluorescence（TADF） layer using 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone（DMAC-DPS） and an ultrathin non-doped yellow phosphorescence layer employing bis[2-（4-tertbutylphenyl）benzothiazolato-N,C2＇]iridium（acetylacetonate）（（tbt）_2Ir（acac））.Two kinds of materials of 4,7-diphenyl-1,10-phenanthroline（Bphen） and 1,3,5-tris（2-Nphenylbenzimidazolyl） benzene（TPBi） are selected as the electron transporting layer（ETL）,and the thickness of yellow EML is adjusted to optimize device performance.The device based on a 0.3-nm-thick yellow EML and Bphen exhibits high color stability with a slight Commission International de l＇Eclairage（CIE） coordinates variation of（0.017,0.009） at a luminance ranging from 52 cd/m^2 to 6998 cd/m^2.The TPBi-based device yields a high efficiency with a maximum external quantum efficiency（EQE）,current efficiency,and power efficiency of 10%,21.1 cd/A,and 21.3 lm/W,respectively.The ultrathin yellow EML suppresses hole trapping and short-radius Dexter energy transfer,so that Forster energy transfer（FRET）from DMAC-DPS to（tbt）_2Ir（acac） is dominant,which is beneficial to keep the color stable.The employment of TPBi with higher triplet excited state effectively alleviates the triplet exciton quenching by ETL to improve device efficiency.

A White Emitting Organic Diode with a Doped Blocking Layer

A novel white emitting organic diode has been simply realized by inserting a doped hole-blocking layer between the hole transporting layer(HTL)and the electron transporting layer(ETL).The structure of this device is ITO/CuPc/NPB/blocking layer:rubrene/Alq/MgAg.Copper phthalocyanine(CuPc)was used as a buffer layer,N,N'-bis-(1-naphthy1)-N,N'-DIPHENYL-1'-biphenyl-4,4'-diamine(NPB)as te HTL,and trimer of complex(Alq) as ETL.Indium tin oxide and MgAg were the anode and cathode,respectively.The emission spectrum of this device covers a wide range of visible region and can be sensitively adjusted by the concentration of rebrene.The white emission with the CIE(Commission International de l'Eclairage)color coordinates x=0.31,y=0.32,a maximum luminance of 8635 cd/m2,and the luminous efficiency 1.39lm/W at the luminance of 100 cd/m2 were obtained in the device with 1.5% rebrene concentration in TPBi.

Tandem white organic light-emitting diodes adopting a C_(60) :rubrene charge generation layer

Organic bulk heterojunction fullerence(C60) doped 5, 6, 11, 12-tetraphenylnaphthacene(rubrene) as the high quality charge generation layer(CGL) with high transparency and superior charge generating capability for tandem organic light emitting diodes(OLEDs) is developed. This CGL shows excellent optical transparency about 90%, which can reduce the optical interference effect formed in tandem OLEDs. There is a stable white light emission including 468 nm and 500 nm peaks from the blue emitting layer and 620 nm peak from the red emitting layer in tandem white OLEDs. A high efficiency of about 17.4 cd/A and CIE coordinates of(0.40, 0.35) at 100 cd/m2 and(0.36, 0.34) at 1000 cd/m2 have been demonstrated by employing the developed CGL, respectively.

Flexible white top-emitting organic light-emitting diode with a MoO_x roughness improvement layer

In this paper, an MoOx film is deposited on a polyethylene terephthalate （PET） substrate as a buffer layer to improve the surface roughness of the flexible PET substrate. With an optimized MoOx thickness of 100 nm, the surface roughness of the PET substrate can be reduced to a very small value of 0.273 nm （much less than 0.585 nm of the pure PET）. Flexible white top-emitting organic light-emitting diodes （TEOLEDs） with red and blue dual phosphorescent emitting layers are constructed based on a low-reflectivity Sm/Ag semi-transparent cathode. The flexible white emission exhibits the best luminance and current injection characteristics with the 100-nm-thick MoOx buffer layer and this result indicates that a smooth substrate is beneficial to the enhancement of device electrical and electroluminescence performances. However, the white TEOLED with a 50-nm-thick MoOx buffer layer exhibits a maximum current efficiency of 4.64 cd/A and a power efficiency of 1.9 lm/W, slightly higher than those with a 100-nm MoOx buffer layer, which is mainly due to an obvious intensity enhancement but limited current increases in 50-nm MoOx-based white TEOLED. The change amplitudes of the Commission International de l’Eclairage （CIE） chromaticity coordinates are less than （0.016, 0.005） for all devices in a wide luminance range over 100 cd/m2, indicating an excellent color stability in our white flexible TEOLEDs. Additionally, the flexible white TEOLED with an MoOx buffer layer shows excellent flexibility to withstand more than 500 bending times under a curvature radius of approximately 9 mm. Research demonstrates that it is mainly attributed to the high surface energy of the MoOx buffer layer, which is conducible to the improvement of the surface adhesion to the PET substrate and the Ag anode.

White Organic Light-emitting Diodes with A Sr_2SiO_4:Eu^(3+) Color Conversion Layer

Abstract:Hybrid inorganic/organic white organic light emitting diodes(hybrid-WOLEDs)are fabricated by combi-ning the blue phosphorescent organic light emitting diodes(PHOLEDs)with red Sr2SiO4:Eu3+phosphor spin coatedas a color conversion layer(CCL)over the other side of glass substrate on the devices.The basic configuration of thePHOLEDs consists a host material,N,N'-dicarbazolyl-3,5-benzene(mCP)which doped with a blue phosphorescentiridium complexes iridium(Ⅲ)bis[(4,6-di-fluorophenyl)-pyridinato-N-C2'](FIrpic)to produce high efficient blueorganic light emitting diodes.The hybrid-WOLED shows maximum luminous efficiency of 22.1 cd/A,maximumpower efficiency of 11.26 lm/W,external quantum efficiency of 10.2%and CIE coordinates of(0.32,0.34).Mo-reover,the output spectra and CIE coordinates of the hybrid-WOLED have a small shift in different driving currentdensity,which demonstrate good color stability.

White Layer of Hard Turned Surface by Sharp CBN Tool

White layers in hard turned surfaces were identified and measured as a function ot turning parameters based on the Taguchi method. It reveals that white layers generate on the machine surface in the absence of tool flank wear, and white layer depth varies with the different combinations of hard turning parameters. Turning speed has the most important impact on white layer depth, feed rate follows, and cutting depth at last. The white layer generation consequently suggests a strong couple relation to the heat generation and thermal process of hard turning operation. White layer disappears under an optimal combination of turning parameters by Taguchi method. It suggests that a superior surface integrity without white layer is feasible under some selected combinations of turning parameters by a sharp CBN cutting tool.

Nondoped-type White Organic Light-Emitting Diode Using Star-Shaped Hexafluorenylbenzene as an Energy Transfer Layer

White organic light-emitting diodes （WOLEDs） with a structure of indium-tin-oxide （ITO）/N,N＇-bis- （1-naphthyl）-N,N＇-diphenyl- （1, 1＇-biphenyl）-4,4＇-diamine （NPB）/1,2,3,4,5,6-hexakis（9,9-diethyl-9H-fluoren-2- yl）benzene （HKEthFLYPh）/5,6,11,12-tetraphenylnaphtacene （rubrene）/tris（8-hydroxyquinoline） aluminum （Alq3）/Mg：Ag were fabricated by vacuum deposition method, in which a novel star-shaped hexafluorenyl- benzene HKEthFLYPh was used as an energy transfer layer, and an ultrathin layer of rubrene was inserted between HKEthFLYPh and Alq3 layers as a yellow light-emitting layer instead of using a time-consuming doping process. A fairly pure WOLED with Commissions Internationale De L＇Eclairage （CIE） coordinates of （0.32, 0.33） was obtained when the thickness of rubrene was 0.3 nm, and the spectrum was insensitive to the applied voltage. The device yielded a maximum luminance of 4816 cd/m2 at 18 V.

Efficient top-emitting white organic light emitting device with an extremely stable chromaticity and viewing-angle

In this paper,we report on the fabrication of a top-emitting electrophosphorescent p-i-n white organic lightemitting diode on the basis of a low-reflectivity Sm/Ag semi-transparent cathode together with a thickness-optimized ZnS out-coupling layer.With a 24-nm out-coupling layer,the reflectivity of the cathode is reduced to 8% at 492 nm and the mean reflectivity is 24% in the visible area.By introducing an efficient electron blocking layer tris（1phenylpyrazolato,N,C2 ＇）iridium（III）（Ir（ppz） 3） to confine the exciton recombination area,the current efficiency and the colour stability of the device are effectively improved.A white emission with the Ir（ppz） 3 layer exhibits a maximum current efficiency of 9.8 cd/A at 8 V,and the Commission Internationale de L＇Eclairage（CIE） chromaticity coordinates are almost constant during a large voltage change of 6 V-11 V.There is almost no viewing angular dependence in the spectrum when the viewing angle is no more than 45,with a CIE x,y coordinate variation of only（±0.0025,±0.0008）.Even at a large viewing angle（75）,the CIE x,y coordinate change is as small as（±0.0087,±0.0013）.

Fabrication of High-power White LEDs and White Light Uniformity Testing

As the blue and yellow lights are complementary colors, a blue InGaN LED chip is coated hy a yellow phosphor film to generate white light based on luminescence conversion mechanism. The emitted light of a blue LED is used as the primary source for exciting fluorescent material such as cerium doped yttrium aluminum garnet with the formula Y3Al2O12 ： Ce^3＋ （in short： YAG ： Ce^3＋ ）. The matching of the spectrum of the blue LED chips and the YAG ： Ce^3＋ yellow phosphor is studied to improve the conversion efficiency. The packaging methods and manufacturing processes for high power single chip-white LEDs are introduced. The uniformity of the output white light is investigated. Based on the characteristics of the high power white LEDs, some approaches and processes are suggested to improve the light uniformity when they are fabricated. The effectiveness of those approaches on the improvement of LEDs is discussed in detail and some interesting conclusions are also presented.

水泥路面加铺Superlayer磨耗层应用技术浅析

水泥混凝土路面在行车荷载和环境因素的综合作用下,会出现不同程度的路面问题,影响道路行车安全与舒适性,通常需要采用"白改黑"技术对水泥混凝土路面进行提升改进。水泥路面加铺超薄磨耗层,具有节省材料与能源、施工速度快、路面改造效果好等特点。本文通过水泥路面加铺Superlayer磨耗层(超薄罩面)的应用实践,选取结构良好的水泥混凝土道路,对Superlayer磨耗层应用于水泥路面表面功能层的实施过程、技术特点进行总结,实践表明Superlayer磨耗层应用于城市道路提升改造效果良好,实践经验可为城市水泥路面提升改造提供经验参考。

A Three-layered Contrasting Analysis of the Theme in Once more to the lake

Once more to the lake is a representative work of the American Writer, Elwyn Brooks White, and has been acclaimed by people in the world. The paper offers a three-layered contrasting analysis of the essay. By detailed analysis of the contrasts running through the whole essay, the author finds that those contrasts are symbol of White's internal struggle and reflection for life.On the foundation of the three-layered contrasts, the paper presents the theme analysis and clarifies the content of the essay.

舰载雷达天线稳定平台横摇滚珠丝杠断裂失效分析

针对某型舰载雷达天线稳定平台发生的横摇滚珠丝杠断裂问题,对失效滚珠丝杠开展失效分析。通过综合分析失效滚珠丝杠的断口分析、化学成分检测、金相检测、硬度检测与力学性能检测结果,认为滚珠丝杠螺纹退刀槽过渡圆角区表面残留的氮化白亮层导致表面脆性增加,促进了疲劳源的产生,材料调质处理后的抗拉强度、下屈服强度偏低,降低了材料的疲劳强度,在超过其疲劳承载极限的横摇交变载荷作用下发生疲劳断裂。通过对滚珠丝杠螺纹退刀槽部位采取防渗氮保护或渗氮处理后彻底去除氮化白亮层,同时优化调质处理工艺参数可以提高该滚珠丝杠的疲劳寿命。

载荷对D2车轮钢滑动磨损表层微观组织和性能影响

目的研究滑动磨损条件下,载荷变化对D2车轮钢表层微观组织和磨损性能的影响。方法利用MRH-30(环块)滑动摩擦磨损试验机进行滑动磨损试验。使用金相显微镜(OM)、场发射扫描电镜(SEM)、X射线衍射仪(XRD)和场发射透射电镜(TEM)等设备,分析滑动磨损后表层微观组织、表面磨损形貌和硬度变化。结果不同载荷条件下,随着磨损时间的增加,轮轨试样磨损量逐渐增加。200 N载荷条件下,(环状)车轮试样的磨损量大于100 N车轮试样磨损量,但200 N钢轨(块状)试样的磨损量却低于100 N钢轨试样。滑动磨损后,在不同载荷条件下,车轮试样表面主要形成长条状白层和不连续的月牙状白层。在200 N载荷条件下,由于车轮试样的磨损量较高,其白层厚度和表面白层硬度都小于100 N载荷条件下的车轮试样。在200 N载荷条件下,车轮试样表面更易形成不连续的月牙状白层。由于轮轨试样表面存在微凸体,高载荷会加速车轮试样表面局部微凸体发生严重塑性变形,导致月牙状白层的形成。在白层内片状渗碳体发生明显溶解和铁素体晶粒显著细化。结论车轮表面白层对磨损性能有明显影响。滑动磨损过程中,高载荷条件下,月牙状白层和周边微观组织界面易形成裂纹,裂纹会逐渐沿着界面向内部扩展,导致不连续月牙状白层发生剥落,降低车轮试样表面的硬度,加速车轮试样磨损。另一方面,高载荷会加速无白层区域塑性变形,导致其形成棘轮失效,从而加速磨损。

镍基单晶高温合金磨削表面白层的形成规律

表面完整性对零件的服役性能和寿命影响至关重要,但是目前仍缺乏关于单晶高温合金加工过程中微观组织演化机制的研究.本文对单晶高温合金磨削过程中的磨削力与温度进行采集,同时对亚表面微观组织以及显微硬度进行表征,研究了表面白层特性.结果表明,在试验参数范围内磨削力和温度随着磨削深度的增加呈现显著上升的趋势,白层和塑性变形层厚度随着磨削深度和进给速度的增加而增大.白层与塑性变形层之间发生元素扩散现象,导致白层富含Al和Ta元素.磨削之后表面显微硬度有所提高,其硬化程度随着磨削深度和进给速度的增加而提高.

混合金属离子的蛋清电解质门控ITO薄膜晶体管

绿色环保生物兼容性电子器件在其鲁棒计算、高效学习及可持续性方面受到了广泛关注。采用绿色环保生物材料鸡蛋清作为双电层薄膜晶体管的栅介质层,通过旋涂、磁控溅射工艺制备蛋清薄膜晶体管并进行电学测试。测试结果显示,器件表现出了较好的电学性能,具有4.5cm^(2)/(V·s)的载流子迁移率、100.2mV/dec的亚阈值摆幅、7.1×10^(7)的高电流开关比、-0.3V的阈值电压。在进行生物突触模拟实验时,成功模拟了兴奋性突触后电流和双脉冲易化等短时程突触行为。而在蛋清中掺杂了K^(+)和Ca^(2+)混合金属离子之后,蛋清薄膜达到了6.4×10^(-4)S/cm较高的质子传导率,栅极电压在-3~3V变化时,蛋清薄膜晶体管栅介质层的漏电流绝对值低于13nA。本研究结果有望应用于新型生物兼容性神经形态器件。

胶质没药中白色不明物质的定性分析

目的对胶质没药中的白色不明物质进行定性分析。方法采用显微、薄层色谱、化学反应和气相色谱等鉴别手段对胶质没药中的白色不明物质和胶质没药对照药材进行比较分析。结果白色不明物质和胶质没药对照药材的显微、薄层色谱、化学反应和气相色谱检测结果无差异。结论胶质没药中的白色树脂与胶质没药对照药材应为相同的物质。

基于多尺度引导滤波的实时视频去雾算法

为解决当前去雾算法中存在的透射率估计不准确、天空区域颜色恢复较差、运行速度较慢等问题,本文提出了一种基于多尺度引导滤波的实时视频去雾算法。首先,采用自动白平衡算法对有雾图像进行颜色校正,颜色校正后的图像与暗原色置信因子作为引导滤波,随后使用金字塔采样技术获取缩小后的图像,接着使用四叉树算法来估算透射率和大气光强度,并且不断地迭代上采样和引导图像滤波,从而有效防止了信息的损失,最后达到最佳的传输效果。此外,将单图像去雾算法扩展到了实时视频去雾,通过使传输值在时间上一致来减少去雾视频中的闪烁伪影。实验结果表明,该算法的运行速率较快,去雾效果明显,在视频去雾中闪烁伪影较少。相比于屏蔽泊松方程去雾算法,本文算法的平均梯度提高了67.08%,相比于暗通道先验逐帧视频去雾算法,本算法的时间加快了81.32%,符合实时视频运行稳定、处理快速的要求。

眼底血管改变与脑白质高信号的相关性分析

目的探讨眼底血管改变与脑白质高信号(white matter hypertensity,WMH)的相关性。方法选取2022年7月至2023年7月于衢州市人民医院神经内科确诊的87例WMH患者作为实验组,同期随机选择80例年龄相匹配的无WMH的健康体检者作为对照组。应用光学相干断层扫描(optical coherence tomography,OCT)及光学相干断层扫描血管成像(optical coherence tomography angiography,OCTA)技术测量两组入选者的视网膜血管结构、微血管密度和神经纤维层(retinal nerve fiber layer,RNFL)厚度等眼底血管参数,比较两组的差异并分析其相关性。结果与对照组比较,实验组患者的视网膜血管结构和微血管密度参数与WMH无相关性。平均、颞上部、鼻下部RNFL厚度减少(P<0.05)。结论OCT与OCTA检测WMH均具有可行性,颞上部、鼻下部视网膜神经纤维层厚度可作为预测WMH发生风险的指标之一。

景区公路路面白改黑应用研究

以实际工程为例,探讨了水泥路面直接加铺沥青层方案的设计思路,并针对反射裂缝等问题提出了相应的处治措施,通过理论计算得出沥青加铺层最小厚度,结合实际施工条件提出设计要点。