Effects of carrier density and interactions on pairing symmetry in a t_(2g) model

By utilizing the fluctuation exchange approximation method,we perform a study on the superconducting pairing symmetry in a t_(2g) three-orbital model on the square lattice.Although the tight-binding parameters of the model are based on Sr_(2)RuO_(4),we have systematically studied the evolution of superconducting pairing symmetry with the carrier density and interactions,making our findings relevant to a broader range of material systems.Under a moderate Hund’s coupling,we find that spin fluctuations dominate the superconducting pairing,leading to a prevalent spin-singlet pairing with a d_(x^(2)-y^(2))-wave symmetry for the carrier density within the range of n=1.5-4 per site.By reducing the Hund’s coupling,the charge fluctuations are enhanced and play a crucial role in determining the pairing symmetry,leading to a transition of the pairing symmetry from the spin-singlet d_(x^(2)-y^(2))-wave to the spin-triplet p-wave.Furthermore,we find that the superconducting pairings are orbital dependent.As the carrier density changes from n=4 to n=1.5,the active orbitals for superconducting pairing shift from the quasi-two-dimensional orbital dxy to the quasi-one-dimensional orbitals d_(xz) and d_(yz).

A Surfing Concurrence Transaction Model for Key-Value NoSQL Databases

As more and more application systems related to big data were developed, NoSQL (Not Only SQL) database systems are becoming more and more popular. In order to add transaction features for some NoSQL database systems, many scholars have tried different techniques. Unfortunately, there is a lack of research on Redis’s transaction in the existing literatures. This paper proposes a transaction model for key-value NoSQL databases including Redis to make possible allowing users to access data in the ACID (Atomicity, Consistency, Isolation and Durability) way, and this model is vividly called the surfing concurrence transaction model. The architecture, important features and implementation principle are described in detail. The key algorithms also were given in the form of pseudo program code, and the performance also was evaluated. With the proposed model, the transactions of Key-Value NoSQL databases can be performed in a lock free and MVCC (Multi-Version Concurrency Control) free manner. This is the result of further research on the related topic, which fills the gap ignored by relevant scholars in this field to make a little contribution to the further development of NoSQL technology.

Lax Pairs for Integrable Six—Vertex Model with Color Paramters

Using the colored Yang-Baxter equation,the Lax pairs for the system with color parameters and periodic boundary conditions are derived.The explicit expressions of the Lax pairs for the six-vertex standard R matrices of both the Baxter and free-Fermion types are given.

Comprehensive Evaluation Model of Reservoir Operation Based on Improved Set Pair Analysis

A comprehensive evaluation model based on improved set pair analysis is established. Considering the complexity in decision-making process, the model combines the certainties and uncertainties in the schemes, i.e., identical degree, different degree and opposite degree. The relations among different schemes are studied, and the traditional way of solving uncertainty problem is improved. By using the gray correlation to determine the difference degree, the problem of less evaluation indexes and inapparent linear relationship is solved. The difference between the evaluation parameters is smaller in both the fuzzy comprehensive evaluation model and fuzzy matter-element method, and the dipartite degree of the evaluation result is unobvious. However, the difference between each integrated connection degree is distinct in the improved set pair analysis. Results show that the proposed method is feasible and it obtains better effects than the fuzzy comprehensive evaluation method and fuzzy matter-element method.

Nucleon—Pair Shell Model：Magnetic Excitations for Ba Isotopes

Magnetic excitations for Ba isotopes are discussed within the nucleon-pair shell model trmicated iti the SDsubspace. With the SD pair determined by a surface-δ interaction, M1 transitions for 1344Ba are well fitted. The M1 andM3 transitions for 132Ba and 130Ba are also predicted. It is shown that the statement, the collective magnetic propertiesarc due to the orbital motion of nucleons, is approximately valid.

Optimal Selection Model of Equipment Design Scheme Based on Set Pair Analysis

Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage.

Cumulative logit model in the analysis of endometrial cancer under a matched pair case-control design

Background: Binary as well as polytomous logistic models are widely used for estimating odds ratios when the exposure of prime interest assumes unordered multiple levels under matched pairs case-control design. In our previous studies, we have shown that the use of a polytomous logistic model for estimating cumulative odds ratios when the outcome (response) variable is ordinal (in addition to being polytomous) under matched pairs case-control design. The cumulative odds ratios were estimated based on separate fitting of the model at each of the cutpoint level as compared to less than equal to that level. In this paper we propose an alternative method of estimating the cumulative odds ratios and reanalyze the Los Angeles Endometrial Cancer data in the context of dose levels of conjugated oestrogen exposure and development of endometrial cancer under the matched pair case-control design. Methods: In the present study, the cumulative logit model is fitted using a single multinomial logit model for the data. For this, the full maximum likelihood estimation procedure is adopted. A test for equality of the cumulative odds ratios across the exposure levels is proposed. Results: The analysis revealed that there is a strong evidence of risk for developing endometrial cancer due to oestrogen exposure above each of the three dose level as compared to less than equal to that level. The estimated values at the three cutpoint levels were found to be 6.17, 3.60 and 5.16 respectively. Conclusions: The odds of developing endometrial cancer are very high for the users of any amount of oestrogen, even if it is the least dose, as compared to the non-users.

Extended Bose-Hubbard model with pair hopping on triangular lattice

We study systematically an extended Bose-Hubbard model on the triangular lattice by means of a meanfield method based on the Gutzwiller ansatz. Pair hopping terms are explicitly included and a three-body constraint is applied. The zero-temperature phase diagram and a variety of quantum phase transitions are investigated in great detail. In particular,we show the existence and the stability of the pair supersolid phase.

Neutral Higgs Boson Pair Production in Standard Model with the Fourth GenerationQuarks at LHC

We investigated the neutral Higgs boson pair production at the CERN Large Hadron Collider (LHC) inthe SM with four families. We found that the gluon-gluon fusion mode is the most dominant one in producing neutralHiggs boson pair at the LHC, and it can be used to probe the trilinear Higgs coupling. If the heavy quarks of the fourthgeneration really exist within the SM, they can manifest their effect on the cross section of the Higgs pair productionprocess at the LHC. Our numerical results show that there will be 2 x 10^4 neutral Higgs boson pair production eventsper year if the next generation heavy quarks really exist, while there will be only 2 x 10^3 events produced per year ifthere are only three families in the SM.

Pairs Trading Strategy for A and H Shares Based on Kalman-HMM Approach

Pairs trading is a statistical arbitrage strategy that takes advantage of unbalanced financial markets.A common difficulty for quantitative trading participants is the detection of market institutional changes in financial markets.In order to solve this issue,the hidden Markov model(HMM)is applied for status detection.The research objective is to use Kalman filter to predict and the hidden Markov model(HMM)to identify state transitions on the basis of screening transaction pairs with obvious co-integration relationship.This research would prove the profitability of the strategy and the ability to resist risk through the combination of these two methods with real data.The empirical results showed that compared with the traditional cointegration strategy,the holding yield increased from 1.6%to 16.2%and the maximum pullback reduced to 0.02%.Further research is required to improve trading rules.

A Method for Automatically Establishing a Mathematical Model of Kinematic Analysis to a Planar Mechanism with a Multiple Joint and Prismatic Pair

A method for automatically establishing a mathematical model of kinematic analysis to a planar mechanism with multiple joint and prismatic pair is presented.The breadth(or depth) first search spanning tree can be obtained based on an adjacency matrix of the mechanism.Then the kinematic chain(or mechanism)'s basic loops can be obtained.On the basis of these basic loops,a mathematical model of kinematic analysis can be established and solved automatically.In the sense of a calculative mechanism,structural analysis of the kinematic chain relates to the kinematic analysis of a mechanism.Thus,an effective way is supplied to the given mechanism's kinematic analysis for automatic modeling and solving,and a method is supplied to the structural type to optimize kinematic synthesis.

考虑表面粗糙度与空化效应的组合密封润滑分析

为了研究表面粗糙度及空化效应对压裂泵柱塞密封副密封性能的影响,基于稳态Reynolds方程,建立了粗糙峰和空化效应影响下组合密封的弹流润滑数值模型.在数值模拟基础上,采用有限体积法求解稳态Reynolds方程,研究了密封副在表面粗糙度影响下的油膜厚度、油膜压力、油膜流速分布规律,以及不同的往复速度和滑环表面粗糙度对密封性能的影响.结果表明,外行程流体动压效应微弱,油膜在空气侧附近会出现空化现象;较高的往复速度有利于减小泄漏量及摩擦阻力;滑环表面粗糙度从0.8μm增加到1.8μm时,净泄漏量与外行程摩擦力分别升高了180.4%和11.17%.因此,在工作过程中应设置较高的往复速度和使用较低粗糙度的滑环以提高密封性能.

基于集对分析理论和数字化平台的山岭隧道塌方风险评价

为更准确、更科学地完成山岭隧道塌方风险评价,提出一种基于层次分析法(AHP)-熵值法(Entropy)集对分析理论的山岭隧道塌方风险评价方法。首先,选取地质因素、设计因素、施工因素、管理因素4项因素作为塌方风险评价指标体系的准则层,选取12项因素作为指标层,运用层次分析法和熵值法分别计算2级指标权重;然后,引入集对分析理论确定指标联系度,并结合置信度准则对塌方风险的等级进行判定;接着,利用Grasshopper以及Python软件,对集对分析理论进行可视化程序开发,并将其与隧道-地质BIM交互模型进行耦合,建立基于AHP-Entropy集对分析模型的隧道塌方风险数字化分析平台;最后,结合重庆某隧道实际工程,验证隧道塌方风险评价的高效化、可视化效果。研究表明:基于集对分析理论的山岭隧道塌方风险评价数字化分析平台运行时间约为2 s,与传统的隧道塌方风险评价方法相比可以大大提高风险评价效率,同时利用AHP-Entropy法确定评价指标权重,提高了评价结果的可靠性。

基于云模型的水光互补清洁能源基地容量配置方案优选

为优选水光互补清洁能源基地容量配置方案,从安全性、环保性、经济性、技术性4个方面选取14个指标构建了综合评价指标体系,采用改进云模型方法对容量配置方案进行评价。改进云模型方法以基于层次分析法改进的云模型求解主观权重,以熵权法求解客观权重,组合赋权得到指标权重,再利用条件云发生器计算各指标的隶属度,最后根据级别特征值法计算容量方案等级评分,确定最优方案。将该方法应用于我国西南某清洁能源基地水光互补系统容量配置方案的优选,优选结果与集对分析法优选结果和实际选择方案均相符,证明了该方法的有效性与适用性。

基于云模型的核心竞争力影响因素分析及评估

为寻找合适的影响因素,提升企业核心竞争力水平,提出基于可拓共轭对分析和云模型的核心竞争力影响因素分析方法。通过对典型农机制造企业分析,运用可拓共轭对分析理论,建立企业内部业务流程和供应链两个角度的虚实、软硬共轭对模型,寻找所有影响因素集合。在此基础上构建基于相对偏好关系的云模型,处理评价信息的不确定性和模糊性,计算核心竞争力初始重要度。引入自相关矩阵进行修正并判断各相关因素的重要度,确定关键核心影响因素。最后通过实例分析验证所提模型的科学性和可行性,帮助企业寻找核心竞争力提升方向。

思考-结对-分享教学模式在产科住培中的应用

目的 探究思考-结对-分享(think-pair-share,TPS)教学模式在产科住院医师规范化培训(简称“住培”)中的应用效果。方法 选择2022年1月—2022年12月在中国医科大学附属盛京医院产科参加住院医师规范化培训的30名住院医师为研究对象,根据不同住培带教方案分为观察组与对照组,各15名。对照组采用传统住培教学模式,观察组采用TPS教学模式进行带教,对比2组住培后技能理论成绩、批判性思维能力和学员满意度。结果 观察组理论成绩[(89.71±4.67)分]和实践考核成绩得分[(90.57±6.77)分]均高于对照组[(70.63±3.75)分、(68.44±4.76)分],差异有统计学意义(P <0.001)。观察组学员批判性思维能力测量表(critical thinking dispostion inventory-Chinese version,CTDI-CV)中思维开放力、求知欲、认知成熟度和自信息等批判性思维项目评分均高于对照组,差异有统计学意义(P <0.001)。观察组学员教学后学习积极性高于对照组,差异有统计学意义(P <0.05)。观察组学员教学后对教学方法、知识掌握、技能掌握和自主学习兴趣等满意度评分均高于对照组,差异有统计学意义(P<0.001)。结论 在产科住院医师规范化培训中应用TPS模式能够提高住培医师理论和技能,增强批判性思维能力且对教学能力接受度更高。

基于空化效应的带排转矩模型优化及试验测试

某重型车辆混合动力传动系统湿式制动器在非制动作业时,由于油液的黏滞作用,摩擦副产生了带排转矩,造成功率损失。为能实现含有复杂沟槽结构流场的带排转矩精准预测,针对空气提前进入流场造成预测误差的问题,提出了一种通过空化数预测空化效应体积分数来优化带排转矩模型的方法。首先,通过不同工况下的模型计算,分析了转速、流量和间隙对空化效应体积分数的影响:随着转速提升,空化效应体积分数先增大后减小;更大的流量和更小的间隙都会使空化效应体积分数的最大值增大。接着,对湿式制动器带排转矩进行了试验测试,对比分析结果显示,优化后模型的预测误差小于6%,相比未考虑空化效应的模型,平均误差减小了55%。此外,还研究了空化效应后沟槽的复杂程度对带排转矩的影响。结果表明,沟槽结构越复杂,带排转矩越小。其中,径向槽的加入对带排转矩的影响最大,可使带排转矩减小约25.9%。研究可为湿式制动器的带排转矩精准预测和摩擦片结构优化提供支持和工程实践指导。

宇宙学模拟中出现本星系群卫星星系对的概率

为检验星系或宇宙学模型,使用近邻宇宙观测提供的暗物质晕中卫星星系相空间分布的独特数据,从卫星星系对的角度,研究宇宙学模拟和观测结果的相似性.在结合星系半解析模型的宇宙学模拟数据中,分别选择类银河系系统和类仙女座星系系统作为研究样本,采用与前人研究相似的相空间判据在较大的样本中计算其中卫星星系成对的比例,得到模拟中出现卫星星系对的概率远小于观测的结果.此结果与已有研究结果基本一致,对类仙女座星系样本使用与观测更相符的投影速度判据可以部分缓解模拟与观测的差别.此外,模拟中位置和速度不确定性较大的一类星系(孤儿星系,即无对应暗物质子结构的星系)对上述结果没有显著影响.

面向运动想象脑电信号识别的多层判别字典对学习方法

面向运动想象的脑机接口(brain computer interface,BCI)能够利用自主想象的特定动作触发脑电信号直接实时控制外部电子设备。运动想象脑电信号(motor imagery electroencephalogram,MI-EEG)存在信噪比低、类内差异大、类间差异小等特点,导致MI-EEG的识别率较低且不稳定。针对该问题,提出了多层判别字典对学习(multilayer discriminant dictionary pair learning,MDDPL)方法。与基于字典学习的MI-EEG识别方法不同,MDDPL将字典对学习融入多层学习模型,通过一系列非线性方法将数据投影到更具判别力的子空间。在综合字典和分析字典的共同作用下,前一层的编码向量作为当前层的输入,同时在每一层模型上构建基于分析字典的多分类项,以保证稀疏编码的分类误差最小化,增强模型的类别区分能力。另外,对最后一层的稀疏编码施加低秩约束,以保证同类编码的紧凑性和相似性。在目标式求解中,使用交替更新策略得到每个参数的解析解,使得参数同时得到最优解。在国际BCI竞赛数据集上的实验结果表明,MDDPL方法在所有对比算法中取得了最佳的分类性能。

基于Pair Copula-GARCH-t的人民币汇率波动实证分析

通过构建Pair copula-garch-t模型,研究人民币对美元、欧元、港元、日元和英镑五种货币汇率收益率序列波动的条件与无条件相关变动关系。实证结果表明,在C藤结构中,人民币对美元汇率序列与人民币对港元汇率序列存在显著无条件正相关,且各收益率序列下尾相关显著高于上尾相关;在D藤结构中,不存在显著无条件相关,两者汇率序列既定的条件下,其他两种汇率存在显著正相关。