Modelling of graded index waveguide fabricated by ion exchange on Er^(3+) doped glass

A general numerical tool, based on thermal diffusion equation and full-vectorial eigen-mode equation, has been presented for the systematic analysis of graded index channel waveguide fabricated by ion exchange on Er^3＋ doped glass. Finite difference method with full-vectorial formulation （FV-FDM） is applied to solving the full-vectorial modes of graded index channel waveguide for the first time. The coupled difference equations based on magnetic fields in FV-FDM are derived from the Taylor series expansion and accurate formulation of boundary conditions. Hybrid nature of vectorial guided modes for both pump （980 nm） and signal light （1550 nm） are demonstrated by the simulation. Results show that the fabrication parameters of ion exchange, such as channel opening width and time ratio of second step to first step in ion exchange, have large influence on the properties of waveguide. By optimizing the fabrication parameters, maintenance of monomode for signal light and improvement of the gain dynamics can be achieved in Er^3＋ doped waveguide amplifier （EDWA） fabricated by ion exchange technique. This theoretical model is significant for the design and fabrication of EDWA with ion exchange technique. Furthermore, a single polarization EDWA, which operates at wavelength from 1528 nm to 1541 nm for HE polarization, is numerically designed.

Monte Carlo Simulation on LED Graded-refractive-index Multilayer Encapsulation Structure

Light propagation in nanoparticle-loaded encapsulants is simulated based on the method of Monte Carlo,referring to the multilayer graded-refractive-index structure for LED encapsulants.And the influence of scattering coefficient on the transmittance is analyzed.The results show that the transmittance decreases with scattering coefficient.For a given number of layers,the encapsulants will yield maximum transmittance if the refractive index value of each layer is optimized.The nanoparticle-loaded encapsulant consists of multiple layers with refractive-index values that gradually decrease.The transmittance will be higher than that of traditional non-graded encapsulants,and will improve light extraction efficiency of LED.

Design of wideband graded-index antireflection coatings at oblique light incidence

We suggest a design method of graded-refractive-index （GRIN） antireflection （AR） coating for s-polarized or p- polarized light at off-normal incidence. The spectrum characteristic of the designed antireflection coating with a quintic effective refractive-index profile for a given state of polarization has been discussed. In addition, the genetic algorithm was used to optimize the refractive index profile of the GRIN antireflection for reducing the mean reflectance of s- and p-polarizations. The average reflectance loss was reduced to only 0.04% by applying optimized GRIN AR coatings onto BK7 glass over the wavelength range from 400 to 800 nm at the incident angle of θo = 70°.

Graded index profiles and loss-induced single-mode characteristics in vertical-cavity surface-emitting lasers with petal-shape holey structure

The 850-nm oxide-confined vertical-cavity surface-emitting lasers with petal-shape holey structures are presented. An area-weighted average refractive index model is given to analyse their effective index profiles, and the graded index distribution in the holey region is demonstrated. The index step between the optical aperture and the holey region is obtained which is related merely to the etching depth. Four types of holey vertical-cavity surface-emitting lasers with different parameters are fabricated as well as the conventional oxide-confined vertical-cavity surface-emitting laser. Compared with the conventional oxide-confined vertical-cavity surface-emitting laser without etched holes, the holey vertical-cavity surface-emitting laser possesses an improved beam quality due to its graded index distribution, but has a lower output power, higher threshold current and lower slope efficiency. With the hole number increased, the holey vertical-cavity surface-emitting laser can realize the single-mode operation throughout the entire current range, and reduces the beam divergence further. The loss mechanism is used to explain the single-mode characteristic, and the reduced beam divergence is attributed to the shallow etching. High coupling efficiency of 86% to a multi-mode fibre is achieved for the single-mode device in the experiment.

Graded index broadband antireflection coating prepared by glancing angle deposition for a high-power laser system

This paper reports that SiO2 is selected to fabricate broadband antireflection （AR） coatings on fused silica substrate by using glancing angle deposition and physical vapour deposition. Through accurate control of the graded index of the SiO2 layer, transmittance of thc graded broadband AR coating can achieve an average value of 98% across a spectral range of 300-1850 nm. Moreover, a laser-induced damage threshold measurement of the fabricated AR coating is performed by using a one-on-one protocol according to ISOl1254-1, resulting in an average damage threshold of 17.2 J/cm2.

Tunability of graded negative index-based photonic crystal lenses for fine focusing

Graded negative refractive index-based photonic crystal （PC） lenses are designed by gradually modifying the sizes of air holes along the transverse direction for focusing the incident plane wave. To study the tunability of the graded negative index-based PC, we introduce filling factor A, gradually tune the filling factor, and use the finite-difference and time-domain （FDTD） algorithm for numerical calculation. Our calculation results indicate that the focal length and the spot size increase with A increasing. For the same A value, the focal length of a PC with elliptical air holes is the longest, and those of PC with square and rectangular air holes are the shortest. Moreover, when the focal length is greater than 1 ~xm, the focal parameters of the PC are highly insensitive to the variation of A. When the focal length is less than 1 gm, the PC lenses have higher transmittances and all well focus with a beam spot size breaking the diffraction limit. This feature possibly makes the graded negative index-based PC lenses have some new applications in optoelectronic systems.

Flat lenses constructed by graded negative index-based photonic crystals with tuned configurations

Flat lenses are designed by means of graded negative refractive index-based photonic crystals （PCs） constructed using air-holes tuned with different shapes. By gradually modifying the filling factor along the transverse direction, we obtain the graded negative index-based lenses for the purpose of focusing an incident plane wave. The finite-difference and timedomain （FDTD） algorithm is adopted for numerical calculation. Our calculation results indicate that these lenses can finely focus incident plane waves. Moreover, for the same size of air-holes, the focusing properties of the lens with rectangular air-holes are better than those with the other shaped air-holes. The graded negative index PCs lenses could possibly enable new applications in optoelectronic systems.

Absorption efficiency of graded-index double-clad fiber lasers

Absorption efficiency of graded-index double-clad fiber lasers or amplifiers is analyzed. As ray optics method is no longer valid for graded-index case, the mode analysis method is used. Calculated results show that absorption efficiency for a graded-index is higher than that for a step-index in symmetric case. In offset core case, the graded-index can achieve the same absorption efficiency with much smaller offset distance. Absorption efficiencies for different graded-index profiles of the inner cladding are compared.

Simplified Model for Light Propagation in Graded-Index-Medium

Using the ray theory of light, a simple theoretical model for the power evolution of a propagating light in graded-index-medium is presented. This work can be useful for different engineering applications that utilize graded-index-material, and for further understanding of natural phenomena that depends on light propagation in graded-index-medium.

Leveraging machine learning techniques for predicting pancreatic neuroendocrine tumor grades using biochemical and tumor markers

BACKGROUND The incidence of pancreatic neuroendocrine tumors (PNETs) is now increasing rapidly. The tumor grade of PNETs significantly affects the treatment strategy and prognosis. However, there is still no effective way to non-invasively classify PNET grades. Machine learning (ML) algorithms have shown potential in improving the prediction accuracy using comprehensive data. AIM To provide a ML approach to predict PNET tumor grade using clinical data. METHODS The clinical data of histologically confirmed PNET cases between 2012 and 2018 were collected. A method of minimum P for the Chi-square test was used to divide the continuous variables into binary variables. The continuous variables were transformed into binary variables according to the cutoff value, while the P value was minimum. Four classical supervised ML models, including logistic regression, support vector machine (SVM), linear discriminant analysis (LDA) and multi-layer perceptron (MLP) were trained by clinical data, and the models were labeled with the pathological tumor grade of each PNET patient. The performance of each model, including the weight of the different parameters, were evaluated. RESULTS In total, 91 PNET cases were included in this study, in which 32 were G1, 48 were G2 and 11 were G3. The results showed that there were significant differences among the clinical parameters of patients with different grades. Patients with higher grades tended to have higher values of total bilirubin, alpha fetoprotein, carcinoembryonic antigen, carbohydrate antigen 19-9 and carbohydrate antigen 72-4. Among the models we used, LDA performed best in predicting the PNET tumor grade. Meanwhile, MLP had the highest recall rate for G3 cases. All of the models stabilized when the sample size was over 70 percent of the total, except for SVM. Different parameters varied in affecting the outcomes of the models. Overall, alanine transaminase, total bilirubin, carcinoembryonic antigen, carbohydrate antigen 19-9 and carbohydrate antigen 72-4 affected the outcome greater than other parameters. CONCLUSION ML could be a simple and effective method in non-invasively predicting PNET grades by using the routine data obtained from the results of biochemical and tumor markers.

The Grey Analysis, Kriging and Selection Index of Flower Yield in Rugosa Rose

The analysis of grey system, kriging interpolation, and integration selection index were employed to investigate the relationships between the flower yield/plant （FY） and 15 other quantitative traits of 20 rugosa rose cultivars. The result showed that： The grey relational grade （GRG） of the number of flowers/plant （NF）, the number of branches/plant （NB）, the width of floral bud （WB）, and the weight/flower （WF） to the FY were larger （〉 0.5）; FY improved with the increase of NF and NB. Moreover, the indirect selection of either trait could not achieve improvement of FY. It is necessary to improve FY by multi-trait selection. The integration selection index （ISI） equation of FY was established with the characters NF, NB, WB, and WF： I= 0.3187x1 - 318.6x2 ＋ 670.1 x4 ＋ 6.3xa, index heritability = 0.8014, selective response of the integration breeding value = 245.8811. This will provide a theoretic basis for the genetic breeding of rugosa rose.

Construction of the Classification and Grading Index System of Cultivated Land Based on the Viewpoint of Sustainable Development

In order to objectively and reasonably evaluate the actual and potential value of cultivated land, both social and ecological values are introduced into the classification and grading index system of cultivated land based on the viewpoint of sustainable development, after considering the natural and economic values of cultivated land. Index system construction of the sustainable utilization of cultivated land should follow the principles of economic viability, social acceptability, and ecological protection. Classification of cultivated land should take into account the soil fertility of cultivated land. Then, grading of cultivated land is carried out from the practical productivity (or potential productivity) of cultivated land. According to the existing classification index system of cultivated land, the soil, natural and environmental factors in plains, mountains and hills are mainly modified in the classification index system of cultivated land. And index systems for the cultivated land classification in plains, mountains and hills are set up. The grading index system of cultivated land is established based on the economic viability (economic value), social acceptability (social value) and protection of cultivated land (ecological value). Quantitative expression of cultivated land grading index is also carried out.

江南华南茶树高温热害等级指标及分布特征

利用1961—2022年江南和华南茶区510个气象站的日最高气温数据和历史茶树高温热害灾情数据,采用灾情反演和K-Means聚类分析方法,构建并验证江南和华南茶区茶树高温热害等级指标,分析茶树高温热害时空分布特征。结果表明:江南和华南茶区茶树轻度、中度、重度高温热害指标为连续14 d日最高气温的滑动平均值T14≥34.5℃的持续日数分别为1~17 d、18~38 d和超过38 d,验证样本完全符合的准确率为73.9%,基本符合的准确率为91.3%;江南和华南茶区茶树高温热害总次数呈波动变化,分别在1999年和1997年达到最低值,并在2021年达到最高值;华南茶区相对于江南茶区高温热害次数更多,尤其是轻度茶树高温热害,且近62年华南茶区茶树高温热害次数增加趋势显著。

Quantifying the Efficiency Advantages of High Viscosity Index Hydraulic Fluids

By providing higher in-use viscosity at elevated operating temperatures,hydraulic fluids with high viscosity index improve the efficiency of the hydraulic system.For mobile hydraulic equipment this efficiency can be quantified as an increase in fuel economy.This paper reviews the research that demonstrates these efficiency advantages in gear,vane and piston pumps and presents a method for predicting the overall fuel economy for a fleet of hydraulic equipment in operation.Finally a `Maximum Efficiency Hydraulic Fluid’ performance definition is presented which will enable an equipment operator to easily improve the performance of the system and reduce fuel consumption.

针刺联合艾灸治疗急性期周围性面瘫的疗效观察

目的 观察针刺联合艾灸治疗急性期周围性面瘫的临床疗效。方法 将60例急性期周围性面瘫患者随机分为治疗组和对照组,每组30例。对照组采用针刺联合药物治疗,治疗组在此基础上采用按摩灸治疗。观察两组治疗前后面部House-Brackmann(H-B)面神经功能分级、肌电图、面部残疾指数(facial disability index,FDI)量表评分变化,比较两组治疗前后炎性因子[超敏C反应蛋白(hypersensitive C-reactive protein,hs-CRP)、白细胞(white blood cell, WBC)计数、中性粒细胞与淋巴细胞的比值(neutrophil-to-lymphocyte ratio, NLR)和血小板与淋巴细胞的比值(platelet-to-lymphoccyte ratio, PLR)]变化,并比较两组临床疗效。结果 治疗组总有效率为96.7%,对照组总有效率为86.7%,两组比较差异有统计学意义(P<0.01)。两组治疗后H-B面神经功能分级优于治疗前(P<0.05),且治疗组的H-B面神经功能分级优于对照组(P<0.05)。两组治疗后口轮匝肌、眼轮匝肌、额肌肌电图潜伏期明显低于治疗前(P<0.05),治疗组低于对照组(P<0.01)。两组治疗后口轮匝肌、眼轮匝肌、额肌患健侧肌电图波幅比值高于治疗前(P<0.01),治疗组高于对照组(P<0.01)。两组治疗后FDI躯体功能评分(facial disability index physical function,FDIP)和社会功能评分(facial disability index social function, FDIS)评分优于治疗前(P<0.01),治疗组优于对照组(P<0.01)。两组治疗后炎性因子水平低于治疗前(P<0.05),治疗组低于对照组(P<0.05)。结论 在药物治疗的基础上,针刺联合艾灸可有效促进急性期周围性面瘫患者面神经功能和社会功能的恢复,疗效优于单纯针刺治疗,其机制可能与改善急性期面神经炎症反应有关。

基于预后营养指数的分级营养护理在行化学治疗胃癌患者中的应用

目的探析基于预后营养指数(PNI)的分级营养护理在行化学治疗(简称“化疗”)胃癌患者中的实施效果和价值。方法回顾分析2020年10月至2022年3月于福建省肿瘤医院接受化疗的胃癌患者的临床资料,共筛选出80例患者。其中,实施常规护理的41例患者为对照组,应用基于PNI的分级营养护理的39例患者为观察组。比较2组的营养指标、免疫功能以及不良反应。结果干预1个月及3个月后,2组的PNI均比干预前升高,血清总蛋白、白蛋白、前白蛋白和血红蛋白水平,以及免疫球蛋白A、免疫球蛋白G和免疫球蛋白M水平均比干预前降低(P均<0.05);观察组的PNI、上述营养指标和免疫指标水平均较同期对照组更高(P均<0.05)。观察组的不良反应(如白细胞减少、口腔黏膜炎等)总发生率较对照组更低(P<0.05)。结论在行化疗的胃癌患者中实施基于PNI的分级营养护理,能够有效改善营养状况和免疫功能,并降低不良反应发生率。

海陆交互相软土固结抗剪强度指标变化规律研究

以珠三角地区海陆交互相淤泥质软土为研究对象,通过室内直剪试验探究不同固结压力和固结度下抗剪强度及抗剪强度指标的变化规律,提出抗剪强度及对应指标-固结度-固结压力三维Logistic数学模型。研究结果表明,当固结压力P≥200 kPa、固结度U≥40%时,软土黏聚力(c)和内摩擦角(φ)增长较为明显;当U=100%时,各级固结压力作用下的软土抗剪强度(τ)相较于初始状态分别提高了7.89、12.73、13.50、18.20、22.38 kPa;所给出的三维数学模型可直接计算出某一固结压力和固结度下的抗剪强度指标c、φ、τ。研究成果能够更为准确地评价该地区软土地基逐级加载过程中的整体稳定性。

黑龙江省三级甲等医院护士长绩效考评指标体系构建

目的构建黑龙江省三级甲等医院护士长绩效考评指标体系,旨在为临床护理管理提供参考依据。方法通过文献分析、理论研究初步编制黑龙江省三级甲等医院护士长绩效考评指标体系框架与内容,采用德尔菲法进行2轮专家函询,最终构建黑龙江省三级甲等医院护士长绩效考评指标体系。结果构建的黑龙江省三级甲等医院护士长绩效考评指标体系包含5个一级指标、14个二级指标、49个三级指标,专家咨询可信度高。结论构建黑龙江省三级甲等医院护士长绩效考评指标体系不仅能为省内各级医疗机构的护理管理者和研究者提供参考依据,还能为护士长提高自身护理管理水平提供实践指导。

不同菜心品种对软腐病的抗性鉴定

【目的】近年来,随着菜心栽培面积扩大和重茬现象的出现,菜心病害逐年加重,其中软腐病是危害菜心的主要病害之一,严重影响其产量和品质。通过接种软腐病病菌对菜心品种进行抗病性评价,以期筛选出抗病品种。【方法】采集具有典型软腐症状的菜心病样,通过组织分离、形态学和分子生物学方法进行鉴定,获得软腐病病菌。以52份不同菜心品种为试验材料,采用苗期喷雾接种法进行接种:用刀片在菜心茎部轻划2个约5mm刀口,使用小型手持喷雾器将1×108CFU/mL菌液喷到伤口表面,接种完成后3 d,测定病情指数和软腐病分级,评价52份菜心品种的软腐病抗性水平。【结果】经组织分离得到分离物,经柯赫氏法则验证菌落形态特征、16S rDNA序列分析表明,菌株为菜心软腐病致病菌,在NA培养基上形成的菌落呈圆形、半透明、乳白色、中心突起、边缘平滑,能使菜心的组织腐烂,接种于菜心苗后叶片呈湿腐萎蔫症状。52份材料中,大多数菜心品种对软腐病的抗性存在显著差异,其中,高感材料35份、感病材料16份,整体而言,高感或感病材料占98.1%;中抗材料1份(丰裕4号菜心);无高抗或免疫品种。上述结果表明,52份菜心品种中抗软腐病的材料较少,这可能是广东省菜心软腐病发病较严重的原因之一。【结论】52份菜心品种中,软腐病高感或感病材料占98.1%;中抗材料1份;无高抗或免疫品种,可为选育和推广抗软腐病的菜心品种提供科学依据。

湖北省雷电灾损特征评估

基于2000-2020年湖北省雷电灾害资料,统计了雷电灾害的等级、经济损失、人员伤亡以及受灾行业等信息,分析了不同等级雷电灾害变化特征、受灾行业以及生命和经济损失特征。结果表明:2000-2020年湖北省雷灾以一般和较大等级为主,占比达96.31%,重大、较大、一般等级雷灾均呈先上升后降低的特征;鄂东地区为雷灾高发区,江汉平原常发生较大及以上等级的雷灾,而鄂西地区以一般等级雷灾为主;农、林、牧、渔业最易遭受雷灾,其伤亡和设备损坏也最严重,但呈下降趋势;制造业因雷灾造成的经济损失最大,尤其是在鄂东北地区;全省生命损失指数呈东高西低的分布特征,高至较高生命、经济损失指数主要集中在鄂东中部地区,少量散布在鄂西北和江汉平原局地。