Thermodynamic and Phase Diagram Modeling of CsF-MF4（M=U, Th） Systems

Phase diagrams for the CsF-UF4 and CsF-ThF4 systems were modeled in the present work through computational thennodynamics. The associate solution model with various complex species（CsMFs, Cs2MF6 and Cs3MF7; M=Th, U） was used to thermodynamically describe the binary molten salts. A total of ten intermediate phases were treated as stoichiometric compounds with their Gibbs energies modeled according to the Neumann-Kopp rule. All these model parameters were optimized by the least squares procedure until good coincidence was achieved between the calculated results and most of the experimental data. The derived thermodynamic parameters will be merged into the multicomponent CsF-LiF-BeF2-ThF4-UF4 database for analyzing physicochemical behavior of CsF in the fuel salt of the molten salt breeder reactor.

Application and comparison of coaxial correlation diagram and hydrological model for reconstructing flood series under human disturbance

Intense human activities have greatly changed the flood generation conditions in most areas of the world, and have destroyed the consistency in the annual flood peak and volume series. For design flood estimation, coaxial correlation diagram and conceptual hydrological model are two frequently used tools to adjust and reconstruct the flood series under human disturbance. This study took a typical mountain catchment of the Haihe River Basin as an example to investigate the effects of human activities on flood regime and to compare and assess the two adjustment methods. The main purpose is to construct a conceptual hydrological model which can incorporate the effects of human activities. The results show that the coaxial correlation diagram is simple and widely-used, but can only adjust the time series of total flood volumes. Therefore, it is only applicable under certain conditions(e.g. There is a strong link between the flood peaks and volumes and the link is not significantly affected by human activities). The conceptual model is a powerful tool to adjust the time series of both flood peak flows and flood volumes over different durations provided that it is closely related to the catchment hydrological characteristics, specifically accounting for the effects of human activities, and incorporating expert knowledge when estimating or calibrating parameters. It is suggested that the two methods should be used together to cross check each other.

Implementation procedure for the generalized moving Preisach model based on a first order reversal curve diagram

First order reversal curves （FORC） of nanocomposite Nd2Fe14B/Fe3B magnetic materials were measured to attain a FORC diagram, which characterizes reversible magnetization, irreversible magnetization, and magnetic interactions in a hysteresis system. Then, generalized mov- ing Preisach model （GMPM） was implemented based on the FORC diagram. Reversible and irreversible magnetizations shown in FORCs and a FORC diagram were used as an input of GMPM. Coupling interaction between reversible and irreversible magnetizations was added when calculating reversible magnetization. Meanwhile, irreversible magnetic moments＇ interaction was approximately represented by mean field interaction. The result shows that the simulated main curves mostly coincide with the experimental curves.

XML Schema Modeling through UML Class Diagram

A three-step XML Schema modeling method is presented, namely first establishing a diagram of conceptual modeling, then transforming it to UML class diagram and finally mapping it to XML Schema. A case study of handling furniture design data is given to illustrate the detail of conversion process.

An implementation of cellular automaton model for single-line train working diagram

According to the railway transportation system＇s characteristics, a new cellular automaton model for the single- line railway system is presented in this paper. Based on this model, several simulations were done to imitate the train operation under three working diagrams. From a different angle the results show how the organization of train operation impacts on the railway carrying capacity. By using the non-parallel train working diagram the influence of fast-train on slow-train is found to be the strongest. Many slow-trains have to wait in-between neighbouring stations to let the fast-train（s） pass through first. So the slow-train will advance like a wave propagating from the departure station to the arrival station. This also resembles the situation of a highway jammed traffic flow. Furthermore, the nonuniformity of travel times between the sections also greatly limits the railway carrying capacity. After converting the nonuniform sections into the sections with uniform travel times while the total travel time is kept unchanged, all three carrying capacities are improved greatly as shown by simulation. It also shows that the cellular automaton model is an effective and feasible way to investigate the railway transportation system.

Calculation of Al Zn diagram from central atoms model

A slightly modified central atoms model was proposed. The probabilities of various clusters with the central atoms and their nearest neighboring shells can be calculated neglecting the assumption of the parameter of energy in the central atoms model in proportion to the number of other atoms i (referred with the central atom). A parameter P α is proposed in this model, which equals to reciprocal of activity coefficient of α component, therefore, the new model can be understood easily. By this model, the Al Zn phase diagram and its thermodynamic properties were calculated, the results coincide with the experimental data.

Modelling and Analysis of the Hubble Diagram of 280 Type SNIa Supernovae and Gamma Ray Bursts Redshifts with Analytical and Empirical Redshift/Magnitude Functions

Based on an analysis of 280 Type SNIa supernovae and gamma-ray bursts redshifts in the range of z = 0.0104 - 8.1 the Hubble diagram is shown to follow a strictly exponential slope predicting an exponentially expanding or static universe. At redshifts > 2 - 3 ΛCDM models show a poor agreement with the observed data. Based on the results presented in this paper, the Hubble diagram test does not necessarily support the idea of expansion according to the big-bang concordance model.

Voronoi-RBSM耦合的混凝土细观建模方法研究

为解决已有混凝土细观数值模拟方法计算效率低、对象尺寸受限的问题,提出一种基于Voronoi网格拓扑和刚体弹簧模型(RBSM)的混凝土细观建模新思路。该模型将混凝土视为由骨料、水泥砂浆组成的二相材料,骨料通过Voronoi单胞描述,视为刚性体,水泥砂浆简化为Voronoi单胞交界面的均布弹簧,弹簧刚度依据局部砂浆的实际情况自动定义。无需对骨料和水泥砂浆进行网格细化,可大大减少单元数量,允许Voronoi单胞在界面处侵入和分离,描述混凝土的变形、开裂等。为验证该文模型的有效性和适用性,开展了室内试验与数值模拟的对比研究,并分析了骨料占比等参数的敏感性。结果表明:基于Voronoi-RBSM的混凝土细观模型,可以较为高效、准确预测混凝土构件在加载过程中细观力学响应,对于尺寸较小的混凝土试件、尺寸较大钢筋混凝土简支梁均有较好的细观模拟效果,尤其是当网格尺寸与骨料平均粒径接近时,预测结果与试验结果最为接近。此外,模型的预测精度受骨料体积占比影响,骨料体积占比越小精度越低,因此,并不适用于浆体占比高的混凝土材料细观数值模拟。

二维图纸驱动三维建模的方法

针对船舶设计过程中二维图纸和三维模型之间缺乏有效关联关系的现状,开展二维图纸驱动三维模型的方法研究。开展常用二维原理图绘制软件CAD和SP P&ID的对比分析;针对CAD软件和SP P&ID两种软件输出的不同形式的二维原理图,分别开展二维原理图驱动三维模型的方法研究,分析二维原理图驱动三维建模的流程,研究二维原理图驱动三维建模的机理,解决二维原理图和三维模型之间数据分离的问题,提高船舶设计效率。

Status,outcome,and related factors of postpartum hypertension in the Shanghai community

BACKGROUND Postpartum hypertension poses a considerable health risk.Despite research on gestational hypertension,comprehensive studies focusing on postpartum hypertension in communities are limited.Understanding its prevalence and associated risk factors is crucial for effective prevention and management.AIM To provide insights for postpartum hypertension’s prevention and management.METHODS In total,3297 women who gave birth between June 2021 and December 2022 in Xuhui District,Shanghai were selected.Blood pressure was measured thrice within one month post-delivery during home visits.Eighty-six women with hypertension were followed up for four months to analyze hypertension persistence and its related risk factors.A predictive model for persistent postpartum hypertension was established and verified using the Nomo diagram model.RESULTS Hypertension prevalence 1 month post-delivery was 2.61%(86/3297).Among the 86 pregnant women,32(37.21%)had persistent hypertension at four months post-delivery.Multivariate logistic regression analysis revealed that older age[odds ratio(OR)=1.212;95%confidence interval(CI):1.065–1.380]and higher pre-pregnancy body mass index(BMI)(OR=1.188;95%CI:1.006–1.404)were associated with hypertension(OR=10.781;95%CI:1.006–1.404)during pregnancy.A 95%CI of 1.243–93.480 is a risk factor for persistent postpartum hypertension.The Nomograph model accurately predicted the risk of persistent postpartum hypertension,demonstrating high precision.CONCLUSION In Xuhui,older age,higher pre-pregnancy BMI,and gestational hypertension are risk factors for persistent postpartum hypertension.Our prediction model can identify high-risk individuals,thereby improving patient quality of life.

心力衰竭患者抑郁风险预测模型的构建与验证

目的:分析心力衰竭(HF)与抑郁的相关因素,基于临床特征建立预测抑郁情绪模型并进行验证。方法:随机抽取2020年1月至2022年12月在天津市第四中心医院就诊的399例HF患者作为研究对象。入院时收集患者的基线信息。使用医院焦虑和抑郁量表(HADS)评估并定义抑郁症状。研究队列按照随机数字表法随机分为训练集和验证集,比例为7:3。利用Logistic回归模型探索与抑郁相关的因素。构建一个列线图来发展预测模型。应用校准曲线评估列线图模型的准确性。通过受试者工作特征(ROC)曲线和决策曲线分析评估预测性能。结果:共140例HF患者(35.09%)出现抑郁症状。多变量Logistic回归分析发现,年龄(OR=0.937,95%CI:0.911~0.964)、婚姻状况(OR=2.466,95%CI:1.099~5.536)、水肿(OR=1.866,95%CI:1.043~3.337)、体力活动水平(OR=1.942,95%CI:1.200~3.143)、生活质量(OR=1.026,95%CI:1.013~1.040)是HF患者抑郁的预测因子。利用以上因素构建的列线图模型显示出良好的一致性和准确性。预测模型和内部验证组的曲线下面积(AUC)分别为0.814(95%CI:0.763~0.864)和0.915(95%CI:0.866~0.964)。Hosmer-Lemeshow检验的P值分别为0.212和0.486(均大于0.05)。结论:年龄、婚姻状况、水肿、体力活动水平、生活质量是HF患者抑郁的预测因子。本抑郁风险预测模型在HF患者中显示出良好的预测性能。

基于AGINet模型的抽油机异常诊断

为克服已有抽油机异常诊断方法中存在的不足,提出一种多尺度结合全局池化的AlexNet模型(简记为AGINet模型)。首先,AGINet模型在已有AlexNet模型中使用批归一化代替原来的局部响应归一化,接着加入Inception模块,最后使用全局平均池化层代替原有的全连接层。基于相同的输入输出和抽油机示功图数据集,分别完成对AGINet模型、AlexNet模型、LeNet5模型、VGG11模型、卷积神经网络和支持向量机的训练和测试。测试结果表明,与其它深度学习模型和支持向量机相比,AGINet模型的分类准确率、召回率的宏平均值、F1的宏平均值、参数量和所占内存大小均有一定程度的改善,具体值分别为99.9%、99.9%、99.9%、338649和1334KB。AGINet模型为油田抽油机的异常诊断提供了重要的技术参考,促进了先进计算机技术在石油工业中的应用。

关于将类图映射成关系表的策略研究

文章研究了类图映射成关系数据库中的表的策略,首先使用Rational Rose 7.0建立类图数据模型,通过给类设置不同的可见性,并在类图中使用类与类之间的各种关系,然后再探讨了类图映射成关系表的规律。实践的结果表明,将类图映射成关系数据库中的表取决于两个因素,即类的可见性和类与类之间的关系,并发现RationalRose7.0软件没有考虑到当属性可见性不同时映射成表中对应的属性也应该是不同的。

肝硬化并发门静脉血栓的风险因素及预测模型构建

目的探讨肝硬化患者并发门静脉血栓(portal veinthrombosis,PVT)的影响因素,并建立肝硬化患者并发PVT的风险预测模型。方法选择2021年1月至2022年11月在南阳市中心医院治疗的139例肝硬化患者为研究对象,将其中并发PVT形成的32例患者作为PVT组,将未并发PVT的107例患者作为非PVT组,收集患者临床资料,采用logistic回归模型分析肝硬化患者并发PVT形成的危险因素,危险因素采用R(R3.5.3)软件建立预测肝硬化患者并发PVT形成的列线图风险预测模型,并验证其预测效能。结果PVT发生率为23.02%;两组患者糖尿病、高血压、脾切除史、纤维蛋白原(fibrinogen,FIB)、白细胞(white bloodcells,WBC)、门静脉主干内径等资料对比差异具有统计学意义(P<0.05)。多因素结果显示,伴有糖尿病、高血压、脾切除史,FIB表达降低、WBC表达升高、门静脉主干内径增加均为肝硬化患者并发PVT形成的独立危险因素(P<0.05)。基于危险因素所构建的列线图模型的模型一致性指数为0.920,校正曲线与理想曲线基本一致,AUC值为0.897。结论伴有糖尿病、高血压、脾切除史,FIB水平降低、WBC水平升高、门静脉主干内径增加均为肝硬化患者并发PVT形成的独立危险因素,基于上述因素构建的列线图模型有助于临床预测肝硬化并发门静脉血栓形成的发生风险。

基于自抗扰控制的H桥逆变器的混沌研究

为了解决新能源发电系统逆变器出现混沌的问题,提出了一种基于自抗扰控制的H桥逆变器的调节方案。针对处于混沌状态的逆变器的稳态和动态特性差的现象,构建了逆变器的离散模型,并通过建立跟踪微分器、扩张状态观测器以及状态误差反馈控制律进行混沌控制。通过分岔图、折叠图以及仿真分析,结果可知基于自抗扰控制的H桥逆变器比基于比例控制的H桥逆变器的稳定范围扩大了45%,有效地抑制了混沌现象的发生。通过分析可得出:该控制策略对系统的混沌行为能够进行抑制,拓宽了系统稳定工作范围。

基于开关流图法的Buck-Boost变换器小信号建模分析

阐述Buck-Boost变换器具有输出纹波低,电压可控等优点,广泛应用于新能源汽车电池发电、直流微电网。建立小信号模型有利于对电路系统主电路的控制和控制回路的设计。分析Buck-Boost变换器,利用开关流图法和信号支路的模型建立变换器的流图,从而推导出变换器的小型号模型。

基于SIF模型与Apriori算法的煤矿顶板事故致因关联分析

为更科学地预防煤矿顶板事故的发生,对煤矿顶板事故致因及其关联规则进行识别十分关键。首先,通过文本挖掘并结合SIF事故致因模型,确定56个影响顶板事故发生的致因;其次,通过构建顶板事故数据库并运用Apriori算法进行顶板事故致因关联规则挖掘;最后,绘制顶板事故致因关联规则复杂网络图,并综合分析顶板事故的核心致因及各致因间的关联规则。结果表明:安全培训教育和安全监督管理、作业人员安全意识淡薄和违反作业规程、当班管理人员在现场的管理不到位和其他事故致因之间有着很高的关联度以及提升度,这些因素是造成煤矿顶板事故发生的核心因素。

基于Roe-Siegmund循环内聚力模型焊趾疲劳裂纹萌生仿真

为建立焊趾疲劳裂纹萌生行为仿真方法,基于Roe-Siegmund循环内聚力模型对ABAQUS进行二次开发,形成用于反映疲劳累积损伤的VUMAT子程序,依据文献方法及试验数据获取Q345焊接区域材料的内聚力参数,通过Voronoi图法和内聚力单元法生成具有疲劳累积损伤特性和晶粒特征的微观模型,并与宏观对接焊缝模型合并,进行多尺度疲劳裂纹萌生仿真模拟,获得裂纹萌生路径、临界循环次数及晶粒力学响应特征.结果表明,此方法能够自发地选择符合实际情况的裂纹萌生位置以及短裂纹扩展路径,完成对焊接区域材料微观断裂过程的模拟,不同仿真组获取的临界循环次数存在于一定的分布范围内,模型中的累积内聚力长度需通过试验数据进行拟合.

基于PT和APTT相关凝血指标分析多囊卵巢综合征危险因素并建立列线图预测模型

目的:基于凝血酶原时间(PT)和活化部分凝血酶原时间(APTT)相关凝血指标分析多囊卵巢综合征(PCOS)危险因素并建立列线图预测模型。方法:选择2021年9月—2022年10月江西中医药大学附属医院中医妇科门诊就诊的PCOS患者199例作为PCOS组,同期在该院进行孕前检查的248例正常女性作为对照组。比较两组各项指标,行单因素和多因素Logistics回归分析,筛选PCOS独立危险因素,并建立列线图预测模型,受试者工作持证曲线(ROC)评估该模型的区分度与准确度,P<0.05为差异有统计学意义。结果:单因素结果分析显示,年龄、抗缪勒氏管激素(AMH)、PT、APTT、凝血酶时间(TT)、纤维蛋白原(Fib)是PCOS危险因素,也是PCOS独立危险因素;构建的Nomogram模型预测PCOS的发生风险阈值为0.07~0.86时,适用性最佳。结论:年龄和AMH,PT,APTT,TT,Fib是PCOS危险因素,同时也提示抗凝治疗可能会改善生殖结局。PCOS的早期筛查和干预对患者长期健康和生命质量具有重要意义,对临床治疗方案的实施具有一定指导意义。

利用转移矩阵模型研究江苏省长江岸线变化

开展长江生态环境监测,推动长江经济带发展是关系国家发展全局的重大战略,是加快推进生态文明建设的客观需要。以2015-2021年江苏省沿江2 km岸线范围内土地利用数据为研究对象,利用转移矩阵模型计算研究区域内各时间节点的转移矩阵表,分析生态、生活和生产空间用地的转入转出以及增减情况;再采用高斯-赛德尔迭代法绘制三生空间流转的桑基图,对江苏省长江岸线变化进行定量分析,为长江经济带(江苏段)的生态监测提供技术支持。