Rain-Flow Modelling Using the GR4J Model for Flood Risk Management in the Oti Watershed (Togo)

In recent years, West Africa has been confronted with hydro-climatic disasters causing crises in both urban and rural areas. The tragedy in the occurrence of such events lies in the recurrent aspect of high water and associated floods. The devastating floods observed in Africa’s major rivers have revealed the need to understand the causes of these phenomena and to predict their behavior in order to improve the safety of exposed people and property. The aim of this study is to reproduce flood flows using the GR4J (Rural Engineering Four Daily Parameters) model to analyze flood risk in the Oti watershed in Togo. Daily data on flows (m3/s), potential evapotranspiration (mm/day) and average precipitation (mm) over the basin from 1961-2022 collected at the National Meteorological Agency of Togo (ANAMET) and the Department of Water Resources in Lome, were used with the R software package airGR. The Data from the West African Cordex program from 1961-2100 were used to analyze projected flows. The results obtained show the GR4J model’s effectiveness in reproducing flood flows, indicating that observed flows are well simulated during the calibration and validation periods, with KGE values ranging from 0.73 to 0.85 at calibration and 0.62 to 0.81 at validation. These KGE values reflect the good performance of the GR4J model in simulating flood flows in the watershed. However, a deterioration in the KGE value was observed over the second validation period. Under these conditions, there may be false or missed alerts for flood prediction, and the use of this model should be treated with the utmost caution for decision-support purposes.

基于J2EE/MVC Model 2的公共图书管理系统的研究

针对当前基于Web的各图书管理系统普遍存在的缺乏业务服务能力的问题,根据多馆共建的思想,提出了一种全新的基于J2EE/MVC Model2的公共图书馆管理系统。分析了J2EE架构,阐述了系统的MVCModel2模式软件架构。给出了4层组件的开发思路,在业务层强调了会话外观和利用BMP精确控制数据库的设计思想,并通过实例介绍BMP的开发过程。系统性能已达到实际使用要求,系统对于树立集成管理、大图书馆管理、创新管理理念,采取科学合理的运行机制有重要意义。

INFLUENCE OF VIRTUAL PHOTON FIELD ON COLLAPSE AND REVIVAL PHENOMENON IN TWO PHOTON J C MODEL WITHOUT RWA

The time evolution of system in two photon Jaynes Cummings (J C) model without rotating waves approximation (RWA) is obtained by using the theory of ordinary differential equations. Based on the evolution, the mean value of the atom inversion operator 〈 S 3(t)〉 is gi ven. The influence of the “counter rotating term” on the collapse and revival phenomenon is discussed from the comparison between the cases with RWA and without RWA. It shows that the influence of the virtual photon field makes the quantum fluctuations appear on the collapse and revival phenomenon.

多周期动态循环应力下的J-A-N力磁耦合机理模型

目前的力磁耦合J-A模型未考虑钉扎场的畴壁厚度与多周期动态循环应力的影响,导致J-A模型的应力磁化数值偏大,不能准确描述早期疲劳损伤。为此,基于畴壁理论和Burgers位错理论,引入畴壁厚度因子,改进J-A模型的钉扎场方程,进一步考虑循环载荷的应力幅、循环周次N等因素,建立了多周期动态循环应力下的J-A-N力磁耦合机理模型。获得了不同动态循环的应力幅值σa与平均应力σm下的磁化规律:相同循环周次下,σa主要影响应力磁化率,σm主要影响应力饱和磁化大小;σm相同时,随着σa的增大,达到应力饱和状态的速度升高;σa相同时,随着σm的增大,应力饱和磁化强度逐渐减小。为验证J-A-N模型有效性,对45钢三点弯曲试件进行了多周期动态循环应力下的磁场信号检测实验,实验结果与模型结果一致。

输尿管软镜钬激光碎石术治疗输尿管上段复杂性结石后双J管附壁结石形成的原因分析

目的:分析输尿管软镜钬激光碎石术治疗输尿管上段复杂性结石后双J管附壁结石形成的原因。方法:选择2015年1月至2023年8月于首都医科大学附属北京潞河医院收治的105例输尿管上段复杂性结石患者,其中男58例,女47例,根据结石评估结果分为结石组(n=40)与非结石组(n=65)。通过随机森林算法分析患者双J管附壁结石形成的影响因素。通过单因素和多因素分析双J管附壁结石形成的独立影响因素,并构建分类树模型。结果:结石组和非结石组CT值、术中出血量、双J管留置时间、白细胞计数(WBC)、C反应蛋白(CRP)、尿酸(UA)、血钙、尿pH值、尿蛋白、尿红细胞、尿白细胞、尿结晶比较差异均有统计学意义(t/χ^(2)值分别为4.361、2.502、6.815、12.176、24.398、15.595、6.517、2.069、6.881、4.524、3.883、4.699,均P<0.05)。双J管留置时间、尿蛋白阳性、尿结晶阳性、UA为双J管附壁结石形成的独立危险因素(P<0.05)。分类树模型显示,双J管留置时间是双J管附壁结石形成的重要预测因素,收益图和索引图显示模型预测良好。结论:双J管留置时间、尿蛋白阳性、尿结晶阳性、UA为双J管附壁结石形成的独立危险因素。临床应重点关注相关因素,及时制定预防策略,以期降低双J管附壁结石的发生风险。

Weldability evaluation and tensile strength estimation model for aluminum alloy lap joint welding using hybrid system with laser and scanner head

Aluminum welding using a hybrid system with a laser and scanner welding head was performed under various welding conditions to verify the feasibility of applying an aluminum alloy to a car body.The experimental material was 5J32 aluminum alloy,and the laser power,welding speed,and laser incidence angle were used as the control variables.The weld bead shape and the tensile shear strength were evaluated in order to understand the aluminum lap joint weld characteristics.Analysis of variance (ANOVA) was conducted to identify the effect of the process variables on the tensile shear strength.Tensile strength estimation models using three different regression models were also suggested.The input variables were the laser power,welding speed,and laser incidence angle,and the output was the tensile shear strength.Among the models,the second-order polynomial estimation model had the best estimation performance,and the average error rate of this model was 0.058.

A j,υ model for the analysis and prediction of tides

In this paper, the j, υ corrected formulae of the amplitudes and the phases of 58 astronomical constituents are given, and the models for the analysis and prediction of 169 constituents are presented. The new Cartwright's calculated results of the tidal potential are used, and the quadratic analysis is made. It has been proved by a number of trials that the harmonic constants of constituents are more stable and the accuracy of the predicted result reliable.

Color-texture segmentation using JSEG based on Gaussian mixture modeling

An improved approach for J-value segmentation （JSEG） is presented for unsupervised color image segmentation. Instead of color quantization algorithm, an automatic classification method based on adaptive mean shift （AMS） based clustering is used for nonparametric clustering of image data set. The clustering results are used to construct Gaussian mixture modelling （GMM） of image data for the calculation of soft J value. The region growing algorithm used in JSEG is then applied in segmenting the image based on the multiscale soft J-images. Experiments show that the synergism of JSEG and the soft classification based on AMS based clustering and GMM overcomes the limitations of JSEG successfully and is more robust.

Two-Photon Nonlinear Jaynes-Cummings Model with Stark Shift

Two photon Jaynes Cummimgs model is generalized to the case of Kerr medium in this paper. The field and atom are prepared initially in two photon superposition state and ground state respectively. Nonlinear coefficient affects the dynamic behaviors of the field and atom. Evolutions of the squeezing for the operators of field and atom and the quantum inversion are discussed. In particular, the higher order squeezing for atomic dipole and the effects of nonlinearity on it, which have not been studied by other authors, are investigated. Increasing the nonlinear coefficient will decrease the squeezing depth of atomic dipole.

Classical Ground State Spin Ordering of the Antiferromagnetic J_1-J_2 Model

The classical frustrated antiferromagnetic J_1–J_2 model is considered in a description of the classical spin wave for a vector spin system. Its ground state(GS) spin ordering is analyzed by minimizing its energy. Our analytical derivations show that all the spins in the GS phase must lie in planes that are parallel to each other. When applying the derived formulations to concrete lattices such as the square and simple cubic lattices, we find that in the large J_2 region, a large continuous GS degeneracy concluded by a qualitative analysis is lifted, and collinear striped ordering is selected as the GS phase.

Protective role of brain CYP2J in diverse Parkinson disease animal models

OBJECTIVE CYP2 family including CYP2C and CYP2J is the predominant arachidonic acid(AA)epoxygenase,and the epoxidation of AA produces four regioisomeric cis-epoxyeicosatrienoic acids(5,6-,8,9-,11,12-,and 14,15-EET).Human CYP2J2 is one of the main CYP isoforms expressed in brain,but CYP2C8 was present at a low level.The aim of this study is to investigate the roles of brain CYP2J in Parkinson disease.METHODS Rats received the right-unilateral y injection with concentrated LV-CYP2J3 or LV-EGFP in the substantia nigra(SN)at 3 d before LPS or 6-OHDA treatment.The animals were tested for rotational behavior with the dopaminergic agonist apomorphine dissolved in sterile saline at 14 and 21 d after LPS injection.The influence of CYP2J-dependent derivative,14,15-EET,on the genes related with oxidative stress was assayed in SH-SY5Y cells.RESULTS CYP2J overexpression or 14,15-EET treatment significantly increased the levels of SOD1,CAT,GPX1,NRF2 and KEAP1 in neurons.TLR4-My D88 signaling pathway was involved the down-regulation of CYP2J by LPS.The binding of p-CREB with the promoter of CYP2J was inhibited by the LPS treatment.The loss of dopaminergic neurons in the right SN induced by LPS or 6-OHDA was significantly decreased by CYP2J3 transfection at 21 d after LPS injection.Compared with LPS or 6-OHDA group,the number of the rotation of rats was decreased by 42.6% and 60.7%by CYP2J3 transfection at 14 d after LPS or 6-OHDA injection;meanwhile,the rotation number was decreased by 12.7%and 21.3%at 21 d.The accumulation of alpha synuclein induced by LPS was significantly decreased by CYP2J3 transfection.The mR NA levels of SOD1,CAT,GPX1,NRF2 and KEAP1 in SN were decreased by LPS,which was attenuated by the injection of LV-CYP2J3.CONCLUSION Brain CYP2J can play a protective role in the damage of the inflammation and oxidative stress to the dopaminergic neurons.Brain CYP2J-dependent derivatives from AA may have therapeutic effects in Parkinson disease via the up-regulation of the antioxidant system in neurons.

D-J管在儿童肾盂成形术中的应用分析——倾向性评分匹配法

目的 D-J管内引流方法在儿童肾盂成形手术后使用中的适应证及预后分析。方法 回顾性分析2012年1月~2022年1月在首都儿科研究所泌尿外科行单侧肾盂成形术的病例,根据术后引流方式不同分为D-J管组(396例)和肾盂造瘘组(334例),应用倾向性评分匹配法对两组病例的基线资料均衡匹配,比较两种引流方式的并发症及预后。结果 D-J管引流能显著减少患者平均住院时间、降低患儿痛苦、减轻皮肤瘢痕,提高医疗及护理质量。D-J管增加患儿术后泌尿道感染和再梗阻风险,临床应用应谨慎。对于D-J管植入术后泌尿道感染建立了包含性别、侧别、身高、肾实质厚度和血尿素氮的预测模型。结论 D-J管内引流方法能显著降低儿童肾盂成形手术后的住院时间、减轻护理负担,虽然这增加了患者近中期尿路感染的风险,但尿路感染的风险可以预测,D-J管在男性、小婴儿和重度肾积水的应用中应谨慎选择。

Study on Project Progress Curve Model

Because of the discrepancy of project types,the project progress curves present different characteristics.Studying project progress curves can reduce management risk of project and overall grasp the enforcement condition of the project.Combining project characteristic,this paper reaches 4 kinds of project progress curve patterns.If the front of the progress curve is concave,and its rear is protruding in the break point,it is named as S model.If its front is protruding and its rear is concave in the break point,it is named as the reverse side of S model.If the front and rear are concave in the break point,it is named as J model,and two half sections are both upward protruding,it is named as the reverse side of J model.Through a case study,it shows that application project progress curve model can better raise project management.

GH738高温合金修正J-C本构关系模型和应变补偿Arrhenius本构关系模型的对比

在变形温度为980~1100℃,应变速率为0.001~0.1 s-1及高度压下率为60%的条件下对GH738高温合金进行了等温恒应变速率压缩实验,研究了合金的流动应力行为,并分别采用J-C模型和Arrhenius模型构建了合金的流动应力本构关系。结果表明,修正J-C模型和应变补偿Arrhenius模型均能较准确表征GH738高温合金的流动应力行为,能较好地预测合金的流动应力,其中修正J-C本构关系模型的相关系数r达0.99172,平均绝对相对误差AARE为7.86%;应变补偿Arrhenius本构关系模型的相关系数r为0.98815,平均绝对相对误差AARE约7.46%。两种本构关系模型具有大体相当的总体预测精度,但对不同变形条件下的预测精度存在一定差异。当应变速率较高、变形温度较低和应变较小时,宜选用修正J-C本构关系模型;反之,宜选用应变补偿Arrhenius本构关系模型。

基于ARMAV模型和J-散度的结构损伤识别

损伤识别技术是结构健康监测系统的关键组成部分,为了进一步提高损伤识别的准确性和适用性,提出一种融合信息距离函数J-散度与向量自回归滑动平均(vector autoregressive moving average,ARMAV)模型的损伤识别方法。采用预白化过滤器对加速度时域数据进行消除激励相关性以及降噪处理;建立了ARMAV模型,并由模型的自回归参数和残差方差构建损伤判别指标;采用三层框架试验数据,并进行转播塔模型的损伤识别试验研究验证了该方法的有效性。结果表明:基于ARMAV模型和J-散度距离的损伤识别方法可操作性强,能够准确、高效地定位框架和塔架结构的损伤,且该方法受环境变化的影响较小,可为在线结构健康监测提供一种新思路。

J-C本构模型参数对45钢钻削仿真结果的影响规律

基于AdvantEdge FEM软件建立了45钢钻削过程的有限元数值仿真模型,通过单因素仿真试验获得了一组用标准麻花钻钻削45钢工件时的扭矩、轴向力、钻削温度和切屑形态仿真数据,并据此研究了45钢J-C本构模型的5个参数(屈服强度、硬化模量、应变率敏感系数、温度软化系数、应变硬化指数)对钻削过程数值仿真结果的影响。结果表明,45钢J-C本构模型的5个参数对其钻削过程数值仿真结果的影响具有明显的规律性。在给定的工艺参数与工件材料J-C本构模型的5个参数的取值范围内,扭矩、轴向力与钻削温度受屈服强度、硬化模量、温度软化系数的影响较大;切屑卷曲半径的变化主要受屈服强度、温度软化系数、应变硬化指数的影响,与参数硬化模量、应变率敏感系数的关系不大。该结果对调整与优化用于钻削过程有限元数值仿真的工件材料J-C本构模型参数,获得准确的钻削过程数值仿真结果有一定的参考价值。

DNAN基含铝炸药低应变率下J-C本构关系

炸药装药的跌落响应问题是典型的低速撞击点火问题,表现出应变率低、脉宽长及脉冲小等特点,与高速冲击点火明显不同。为研究典型水中兵器战斗部装药跌落条件下的动态力学特征,利用分离式霍普金森压杆对二硝基苯甲醚(DNAN)基含铝炸药进行动态压缩试验,通过入射波整形技术实现了常应变率加载,得到了常温常压条件下80、180、280、360和440 s^(-1)等5种低应变率下DNAN基含铝炸药的应力应变曲线,采用Johnson-Cook(J-C)本构模型对试验数据进行了参数拟合,并结合数值仿真加以验证。结果表明:DNAN基含铝炸药的弹性模量、屈服强度、屈服应变、失效应力及失效应变均随应变率的提高而增大。利用拟合得到的J-C本构参数可以在数值仿真中很好地还原DNAN基含铝炸药在低应变率下的动态力学行为,从而为相关跌落安全性数值仿真计算提供数据支撑。

上尿路结石术后并发双J管相关性尿路感染列线图风险预测模型的构建

目的:探讨上尿路结石病人术后并发双J管相关性尿路感染的危险因素,并构建其列线图风险预测模型。方法:回顾性收集2020年7月-2022年6月某三级甲等综合医院收治的216例上尿路结石并留置双J管病人,根据双J管相关性尿路感染的发病情况将其分为感染组与非感染组,采用单因素分析、Logistic回归分析上尿路结石病人术后并发双J管相关性尿路感染的危险因素,构建列线图风险预测模型并评价该模型的实际效用。结果:上尿路结石病人术后并发双J管相关性尿路感染29例(13.43%)。Logistic回归分析结果显示,合并糖尿病、中性粒细胞与淋巴细胞比值(NLR)和肾积水程度是上尿路结石病人术后并发双J管相关性尿路感染的独立危险因素。列线图风险预测模型内部验证结果显示,Hosmer-Lemeshow检验χ^(2)=6.981,P=0.639,ROC曲线下面积为0.853[95%CI(0.774,0.934)]。结论:构建的列线图风险预测模型具有良好的预警作用,为医护人员早期识别上尿路结石术后并发双J管相关性尿路感染的高危人群,及时采取有效的预防措施降低感染率提供依据。

核电站常用管道材料J-C本构模型参数识别及验证

针对核电站管道在受到地震等灾害产生的偶然冲击载荷作用时的应力流动与变形情况,采用电子万能试验机和高速拉伸试验机,分别对碳钢A106(A-106 GR.B)、不锈钢304L(A-312 TP304L)、合金钢A335(A-335 GR.P11)3种核电站常用的管道材料进行准静态拉伸与动态拉伸试验,并根据试验所得结果拟合建立了3种材料的Johnson-Cook(J-C)本构模型。利用Abaqus有限元分析软件建立管道的冲击模型,并通过冲击试验台架对仿真结果进行验证。结果表明,3种材料都出现了明显的应变率强化效应,A335的抗冲击能力更好一些,304L与A106抗冲击能力差别不大。试验结果与仿真结果吻合度良好,拟合得到的J-C本构模型参数可靠性较高,能够准确地描述材料在冲击载荷下的应力流动与变形行为,对核电站常用管道受冲击载荷作用仿真分析研究具有十分重要的意义。

泌尿系统术后留置双J管患者并发尿路感染列线图预测模型建立及验证

目的通过建立泌尿系统术后留置双J管患者尿路感染(UTI)临床预测模型,提高临床对于此类患者的诊治能力。方法选择2018年1月~2022年7月本院泌尿外科接受手术留置双J管患者为研究对象,经病历筛选最终入组研究对象共137例,将尿路感染患者纳入UTI组,未发生尿路感染者纳入非UTI组。对性别、年龄、体质量指数(BMI)、双J管留置时间、合并糖尿病、尿路感染史、术前营养控制状态评分(COUNT)、手术时间、双J管侧别、合并肾功能不全情况进行统计,采用R-studio 4.0.2软件的“RMS”函数包完成多因素Logistic回归模型建立、列线图绘制,模型及单因素对双J管感染的诊断价值分析采用受试者工作特征曲线(ROC)进行评价。结果UTI组与非UTI组性别、年龄、BMI、合并糖尿病、手术时间、双J管侧别、合并肾功能情况比较差异无统计学意义(P>0.05),UTI组双J管留置时间、术前COUNT评分、尿路感染史比例均高于非UTI组(P<0.05);多因素Logistic回归分析结果发现双J管留置时间、尿路感染史、术前COUNT评分均为泌尿系统术后留置双J管相关尿路感染的独立影响因素(P<0.05),Bootstrap法对预测模型列线图进行内部验证,Hosmer-Lemeshow检验结果显示χ2=6.753,P=0.325,说明模型具有良好的校准度;ROC分析结果显示,双J管留置时间、尿路感染史、术前COUNT评分预测术后尿路感染的曲线下面积(AUC)分别为0.793、0.747、0.750,3个单因素联合建立的预测模型预测术后尿路感染的AUC为0.925,均具有良好的预测效能(P<0.05)。结论基于双J管留置时间、尿路感染史、术前COUNT评分所建立的预测模型对泌尿系统术后留置双J管患者尿路感染的发生概率有较好的预测能力,可在早期识别尿路感染高风险人群。