压气机端区堵塞模型的建立和验证

根据扩张管道边界层理论并且从边界层动量积分关系式出发,提出了用于轴流压气机初始设计的端壁区堵塞发展模型,该模型可以在初始设计阶段方便的预测压气机端壁区堵塞的发展．通过轴流压气机扩压叶栅的数值模拟,将模型预测值与数值模拟结果进行对比分析,验证了该模型的准确性和适用性。     

干扰素抗病毒药效学评价研究进展

肝炎病毒通过血液和体液传播,严重威胁人类的健康。开发有效的抗HBV药物对于治疗该疾病非常关键。HBV对宿主的选择具有很强的专一性,因此选择合适的评价模型至关重要。目前用于评价干扰素抗病毒效果的模型主要有体外细胞模型、转基因小鼠模型等。     

基于HBV水文模型的青藏高原卡鲁雄曲流域径流预报

青藏高原平均海拔4000m以上,气候恶劣。区域内产汇流规律复杂且水文实测资料稀缺,给流域水文模拟和分析带来诸多挑战。文章选用HBV水文模型在卡鲁雄曲流域进行水文模拟,数据资料包括卡鲁雄曲翁果水文站2010-2015年逐日降水、气温、观测流量等数据。结果表明,模型在率定期、验证期Nash系数分别达到0.82、0.84,HBV水文模型在卡鲁雄曲流域有较好的适用性。但是受到高寒气候影响和水文资料代表性较差的原因,HBV模型在高流量和低流量部分的流量模拟上表现差,相较于实际观测,模拟的径流总量估计出现低估,但总体来说HBV水文模型在卡鲁雄曲流域有较好的适用性。     

浅议水文工程地质条件及渗漏措施

本文分析了三维渗流数值模型.通过对数值模拟证实了该湖建成后确实存在渗漏量过大的问题,并为解决这些环境地质问题提供参考方案,还预测分析了环境水文地质条件改变后可能进一步出现的问题并提出了相应的解决方案.     

解释变量内生假定下非参数空间计量模型的局部线性工具变量估计

为刻画解释变量的空间外溢效应与变量间的非线性关系,本文提出了一种非参数空间计量模型,并给出了模型含内生变量情况下的局部线性工具变量估计。该估计方法最大的优点是可以同时获得偏导数的估计,便于进行经济学的边际分析。数值模拟结果表明,局部线性工具变量估计优于核估计。中国地区R&D要素外溢效应的实证结果显示,周边地区R&D内部经费支出对本地区R&D产出具有非线性的正向影响,且周边地区R&D内部经费支出的边际产出存在空间集聚现象,实证结论显示了非参数空间计量模型的适用性与合理性。     

朴沟桥体外预应力加固有限元分析

为了建立正确的有限元模型对桥梁的体外预应力加固进行仿真模拟,通过使用ANSYS对朴沟桥的体外预应力加固进行非线性有限元模拟,分析了朴沟桥加固前后受力全过程,并与检测数据进行了对比分析,得出该模型比较真实的模拟了加固前后桥梁的受力,该方法适用于该领域的数值研究。     

微孔注塑数值模拟技术的研究进展

阐述了气泡长大过程的两种典型模型,综述了近年来数值模拟技术在微孔注塑领域的应用,并分析了模型简化、参数选择、算法技巧等对微孔注塑数值模拟准确性的影响,最后展望了微孔注塑数值模拟技术的发展。     

沉积微相约束条件下的随机地质建模方法及应用研究

以地质建模为主要研究对象,根据油田开发地质研究需要完善的方法技术,以建模方法研究为基础,进行了沉积微相约束地质建模综合研究.在分析目前国内外研究现状的基础上,针对我国开发地质研究工作的特点,提出根据测井解释成果,应用随机模拟的方法定量地开展沉积微相研究.应用沉积微相研究成果约束测井储层参数的分布,形成油藏数值模拟研究所需要的准确的储层三维地质模型,解决了常规油田开发地质研究过程中沉积相研究成果与储层参数分布无法有效结合的缺陷.应用与该方法相适应的IRMS软件成功实现了山东胜利油区孤东油田第七开发区西部上第三系馆陶组油藏精确的沉积微相模型,由此微相约束形成的油藏储层三维地质模型数据体直接应用于油藏数值模拟研究,应用效果及现场实施的效果良好.     

山岭隧道围岩监测及Ⅳ级围岩变形规律模拟研究

为准确掌握某山岭隧道开挖后围岩水平收敛、拱顶下沉及衬砌受力特点,基于隧道围岩变形和应力监测结果,提出了该山岭隧道施工监测技术要点,得到了Ⅲ、Ⅳ级围岩的位移和衬砌受力变化规律;并采用FLAC软件对该山岭隧道Ⅳ级围的变形进行了数值模拟,数值计算的位移值与实测值较吻合,表明该数值模型可应用于隧道开挖过程实时仿真,指导现场施工监测工作,保证施工作业安全。     

潮流数学模型在近岸海域环境功能区划调整中应用—以丹东海洋红港区为例

通过构建一个合适的近岸海域的潮流数学模型,并将模型应用在海洋红港区,以解决该近岸海域环境功能区划调整及排污口法选择问题。通过模拟预测避免了排污口的不利选择给环境造成的危害。将数值模拟计算结果与物理模型试验结果进行比对分析,数值模拟计算结果与物理模型试验结果吻合情况良好。因此,基于ADI数值模型对近岸海域潮流场的二维数值模拟是可行的。     

Circulating Biomarkers and their Possible Role in Pathogenesis of Chronic Hepatitis B and C Viral Infections

The present study evaluated the plausible role of circulating biomarkers in immune pathogenesis of chronic hepatitis considered a priority in clinical hepatology. Total viral load of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) patients was quantified and correlation studies were performed with circulating levels of Th1/Th2 cytokines; C reactive protein and circulating nucleosomes; glutathione reductase (GR) and superoxide dismutase. To our knowledge, the study is first among its kind that validates strong positive correlation of viral load with IL-4, IL-6, GR in HBV and IL-6, IL-10, GR in HCV infections. Although, multi-centric studies including large cohorts are required for translating our findings to clinical practice, however, role of these biomarkers with potential diagnostic or prognostic significance might be helpful in clinical assessment of high-risk individuals, thereby, designing interventional strategies, towards development of personalized medicare. The results of our study also offer valuable insights of immune signaling mediators engaged in development of hepatocellular carcinoma.     

Numerical simulation of intracellular drug delivery via rapid squeezing

Intracellular drug delivery by rapid squeezing is one of the most recent and simple cell membrane disruption-mediated drug encapsulation approaches. In this method, cell membranes are perforated in a microfluidic setup due to rapid cell deformation during squeezing through constricted channels. While squeezing-based drug loading has been successful in loading drug molecules into various cell types, such as immune cells, cancer cells, and other primary cells, there is so far no comprehensive understanding of the pore opening mechanism on the cell membrane and the systematic analysis on how different channel geometries and squeezing speed influence drug loading. This article aims to develop a three-dimensional computational model to study the intracellular delivery for compound cells squeezing through microfluidic channels. The Lattice Boltzmann method, as the flow solver, integrated with a spring-connected network via frictional coupling, is employed to capture compound capsule dynamics over fast squeezing. The pore size is proportional to the local areal strain of triangular patches on the compound cell through mathematical correlations derived from molecular dynamics and coarse-grained molecular dynamics simulations. We quantify the drug concentration inside the cell cytoplasm by introducing a new mathematical model for passive diffusion after squeezing. Compared to the existing models, the proposed model does not have any empirical parameters that depend on operating conditions and device geometry. Since the compound cell model is new, it is validated by simulating a nucleated cell under a simple shear flow at different capillary numbers and comparing the results with other numerical models reported in literature. The cell deformation during squeezing is also compared with the pattern found from our compound cell squeezing experiment. Afterward, compound cell squeezing is modeled for different cell squeezing velocities, constriction lengths, and constriction widths. We reported the instantaneous cell center velocity, variations of axial and vertical cell dimensions, cell porosity, and normalized drug concentration to shed light on the underlying physics in fast squeezing-based drug delivery. Consistent with experimental findings in the literature, the numerical results confirm that constriction width reduction, constriction length enlargement, and average cell velocity promote intracellular drug delivery. The results show that the existence of the nucleus increases cell porosity and loaded drug concentration after squeezing. Given geometrical parameters and cell average velocity, the maximum porosity is achieved at three different locations: constriction entrance, constriction middle part, and outside the constriction. Our numerical results provide reasonable justifications for experimental findings on the influences of constriction geometry and cell velocity on the performance of cell-squeezing delivery. We expect this model can help design and optimize squeezing-based cargo delivery.     

Cytochrome P450 Genes (CYP2E1 and CYP1A1) Variants and Susceptibility to Chronic Hepatitis B Virus Infection

Hepatitis B virus (HBV) infection is a worldwide health concern which is associated with significant morbidity and mortality. Both viral and host factors have a significant effect on infection, replication and pathogenesis of HBV. The aim of this study was to investigate the effect of CYP2E1 and CYP1A1 genetic variants on susceptibility to HBV. 143 individuals including 54 chronic HBV patients and 89 healthy controls were enrolled in the genotyping procedure. rs2031920 and rs3813867 at CYP2E1 as well as rs4646421 and rs2198843 at CYP1A1 loci were studied in all subjects using PCR–RFLP (restriction fragment length polymorphism) analysis. Both variants at CYP2E1 locus were monomorphic in all studied subjects. Genotype frequency of rs4646421 was significantly different between chronic HBV patients and healthy blood donors (P = 0.04, OR 4.31; 95% CI 1.04–17.7). Furthermore, individuals carrying at least one C allele (CC or CT genotypes) for rs4646421 seemed to have a decrease risk of hepatitis in comparison with TT genotype (P = 0.039). Our results showed a relationship between rs4646421 TT genotype (rare genotype) and the risk for developing chronic HBV infection (four times higher). Further studies are needed to examine the role of CYP1A1 polymorphism in susceptibility to chronic HBV infection.     

The hepatitis B virus-associated tumor microenvironment in hepatocellular carcinoma

In contrast to a majority of cancer types, the initiation of hepatocellular carcinoma(HCC) is intimately associated with a chronically diseased liver tissue, with one of the most prevalent etiological factors being hepatitis B virus(HBV). Transformation of the liver in HBV-associated HCC oten follows from or accompanies long-term symptoms of chronic hepatitis, inlammation and cirrhosis, and viral load is a strong predictor for both incidence and progression of HCC. Besides aiding in transformation, HBV plays a crucial role in modulating the accumulation and activation of both cellular components of the microenvironment,such as immune cells and ibroblasts, and non-cellular components of the microenvironment, such as cytokines and growth factors, markedly inluencing disease progression and prognosis. his review will explore some of these components and mechanisms to demonstrate both underlying themes and the inherent complexity of these interacting systems in the initiation, progression, and metastasis of HBV-positive HCC.     

基于学科引文的文献生命周期模型探析

基于文献老化负指数模型与生命周期曲线并借助函数推导与曲线分析方法,揭示出文献老化率在负指数模型中为常量,而在生命周期曲线下则为时间函数且具有复杂的数学特征。在此基础上,深入探讨了文献生命周期数学模型的理论特征、模型构建与数学验证问题。结果表明对数正态模型能够较好地拟舍学科引文历时分布数据且符合文献生命周期理论曲线与老化率函数的典型数学特征。     

基于信息粒化的数据拟合模型对城市主干道交通违法数据分析——以南京市中心城区为例

通过对城市交通大数据的分析,研究中心主城区主干道路交通违法行为。利用优化的数学模型进行数字化及可视化分析,找出交通违法行为的现状和分布规律;采用粒计算的思想对数据进行信息粒化,在周期性的数据中找到数据的总体波动,剥落Low层数据,筛选出Up层和R层数据,选取不同模型对数据进行线性拟合与对比,显示Fourier级数模型拟合结果更优;对每条路线的车辆交通违法信息逐一分析,结果显示二号路线在7—8月份出现车辆交通违法56.38次,四号线路线在6月份出现8次。文中建立新的数学模型来处理周期性数据,模型精确度高,能明确评估城市交通违法情况。     

基于Matlab的一阶倒立摆系统建模及仿真

倒立摆系统是一个典型的快速、多变量、非线性、不稳定系统,建立其数学模型研究其稳定性对于很多工程控制有着重大意义。论文采用机理建模法对一阶倒立摆系统进行分析,建立其数学模型。采用Matlab软件进行仿真验证,仿真结果表明,实验结果符合实际实验设计,所建立的一阶倒立摆系统的数学模型是有效正确的。     

机械结构对两轮移动足球机器人运动精度影响研究

以自行设计的两轮移动足球机器人的机械结构为对象,从理想情况和实际情况分别进行机器人小车的运动学分析与建模,进行比较并得出结论。分析了驱动轮半径对运动学模型的影响。最后从机械结构的设计上讨论了对小车运动精度的影响,并提出相关改进措施。     

企业技术联盟分析

本文运用博弈分析模型及数学规划模型对我国跨国公司与发达国家跨国公司两竞争对手间组建技术联盟、国内技术关联企业组建技术联盟进行分析 ,说明技术联盟对改变我国企业技术发展轨道以及提升我国整体技术水平都有着重要的作用     

Battle-outcome-prediction conditions for variable-coefficient Lanchester-type equations for area fire2

New important battle-outcome-prediction conditions are developed for combat between two homogeneous military forces modelled by variable-coefficient Lanchester-type equations for area fire. Such conditions are very significant in modern operations research for developing important insights into the dynamics of combat. However, similar differential-equation models do arise in other fields of science and technology such as mathematical ecology and epidemiology, and consequently our new mathematical results may also find application there. These new important “simple approximate” battle-outcome-prediction conditions depend on not only the combat-attrition model but also the battle-termination model, and they are developed for two different types of battle-termination conditions (fixed-force-level-breakpoint battles and fixed-force-ratio-breakpoint battles). They are sufficient (but not necessary) to determine the outcome of battle without having to explicitly compute the force-level trajectories, and a generalization of Lanchester’s famous linear law to variable-coefficient combat is involved in their development. Certain integrability properties of the Lanchester attrition-rate coefficients figure prominently in these results, and an important physical interpretation (relating to logistics considerations) is given for these properties.