Finite element analysis of anchor plates using non-coaxial models

The non-coaxial model simulating the non-coincidence between the principal stresses and the principal plastic strain rates is employed within the framework of finite element method（FEM） to predict the behaviors of anchors embedded in granular material.The non-coaxial model is developed based on the non-coaxial yield vertex theory,and the elastic and conventional coaxial plastic deformations are simulated by using elasto-perfectly plastic Drucker-Prager yield function according to the original yield vertex theory.Both the horizontal and vertical anchors with various embedment depths are considered.Different anchor shapes and soil friction and dilation angles are also taken into account.The predictions indicate that the use of non-coaxial models leads to softer responses,compared with those using conventional coaxial models.Besides,the predicted ultimate pulling capacities are the same for both coaxial and non-coaxial models.The non-coaxial influences increase with the increasing embedment depths,and circular anchors lead to larger non-coaxial influences than strip anchors.In view of the fact that the design of anchors is mainly determined by their displacements,ignoring the non-coaxiality in finite element numerical analysis can lead to unsafe results.

肥胖儿童non-HDL-C、remnant cholesterol与亚临床动脉粥样硬化的关系

目的:了解non-HDL-C和remnant cholesterol与肥胖儿童亚临床动脉粥样硬化(AS)的关系。方法:根据甘油三酯(TG)水平将65例肥胖儿童(肥胖组)分为I组(TG≥2.3 mmol/L)32例,II组(TG<2.3 mmol/L)33例,与肥胖组儿童性别年龄相匹配的正常体质量儿童30例为III组(对照组)。比较3组儿童血脂指标,对肥胖组各项血脂指标与血浆致动脉粥样硬化指数(AIP)进行相关性分析,肥胖患儿体质指数、血脂指标与颈动脉内径、内膜-中层厚度(c-IMT)、血流参数进行相关性分析。结果:I组、II组的TG、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、non-HDL-C、remnant cholesterol、AIP均较对照组升高,高密度脂蛋白胆固醇(HDL-C)较对照组降低,且I组的remnant cholesterol、AIP均较II组升高。肥胖组儿童AIP与TG、non-HDL-C、remnant cholesterol呈正相关,与HDL-C呈负相关。37例行颈动脉超声检查的肥胖儿童的c-IMT较正常儿童的增厚。结论:non-HDL-C、remnant cholesterol在肥胖儿童亚临床AS中有重要作用,在肥胖儿童血脂异常的治疗中应关注non-HDL-C、remnant cholesterol的变化。

Shenqi Fuzheng injection combined with GP chemotherapy in the treatment of advanced non-small cell lung cancer： a meta-analysis

Objective： To evaluate the clinical efficacy of Shenqi Fuzheng injection combined with gemcitabine plus cisplatin（GP） in the treatment of advanced non-small cell lung cancer （NSCLC）. Methods： we performed a systematicsearch in the electronic databases such as Cochrane Library, Pubmed, Embase, Chinese Journal Full-text Database,Chinese Biomedical Literature Database, Chinese Science and Technology Periodical Full-text Database andWanfang Database up to 30 January 2017. Randomized controlled trials （RCT） of Shenqi Fuzheng Injectioncombined with GP chemotherapy in the treatment of advanced NSCLC were searched, and all the RCTs wereconducted on methodological quality assessment. Data extraction and data analysis were according to standards ofCochrane systematic review. Results： Eight trials were included including a total of 701 patients. Meta-analysisresults： Shenqi Fuzheng injection combined with GP chemotherapy could significantly improve the functionalstatus of patients with NSCLC （OR = 3.44, 95% CI [2.26, 5.25], P 〈 0.0001） and clinical treatment efficacy （OR =（OR = 0.31, 95%CI [0.20, 0.47], P 〈 0.0001. The rate of leukopenia （OR = .31, 95%CI [0.20,0.47], P 〈 0.0001）,thrombocytopenia （OR = 0.58, 95%CI [0.37, 0.91], P = 0.020）, hemoglobin decline （（OR = 0.31, 95%CI [0.16,0.59], P = 0.0004） and incidence of gastrointestinal reactions （OR = 0.58,P 〈 0.05） could be reduced. Conclusion：Shenqi Fuzheng injection combined with GP chemotherapy in the treatment of advanced NSCLC obtainedsignificantly clinical efficacy. The quality of the literature incorporated is low, the conclusion requires high-qualityresearch to further prove.

MHD UNSTEADY FLOWS DUE TO NON—COAXIAL ROTATIONS OF A DISK AND A FLUID AT INFINITY

Exact analytical solution for flows of an electrically conducting fluid over an infinite oscillatory disk in the presence of a uniform transverse magnetic field is constructed. Both the disk and the fluid are in a state of non-coaxial rotation. Such a flow model has a great significance not only due to its own theoretical interest, but also due to applications to geophysics and engineering. The resulting initial value problem has been solved analytically by applying the Laplace transform technique and the explicit expressions for the velocity for steady and unsteady cases have been established. The analysis of the obtained results shows that the flow field is appreciably influenced by the applied magnetic field, the frequency and rotation parameters.

Analysis of Numerical Results in High Temperature Congealment and Chemistry Non-equilibrium Flow Field

Using the air plasma ignition technique, physicochemical process of burning can be accelerated; concentration limit ofretrofires both can be extended; reliability of retrofires and stability of burning can be improved. In this paper, using internalequivalent heat area in place of electric are that created Ohm heat, the flow fields of thermodynamic equilibrium chemistry con-gealment and chemistry non-equilibrium in the plasma generator were simulated. The influences of the inlet prerotation angleof air, the inlet total pressure of air and the airflow compression angle of spray nozzle on the temperature on the surface of elec-

Turbulent Flow Action of Pulp in Wet - Laid Non - Woven Processes

The paper deals with the fluid field of web forming in wet-laid non-woven production.The influence of the turbulent flow on blending fiber and occluded fluid produced in pulp flow has been discussed in theory and practice.The suitable use of the imported velocity of pulp is very important in producing wet-laid products of good quality.

CYFRA 21-1 as an early predictor of first line chemotherapy response in advanced non small cell lung cancer

Objective： In an era of ever evolving, promising new therapies for advanced non small cell lung cancer （NSCLC）, early predictors of response to therapy, are needed. We evaluated early variations in CYFRA 21-1 serum levels of patients with advanced NSCLC receiving first line chemotherapy and correlated the results with objective tumor response. Methods： 29 consecutive, previously untreated, patients of advanced non small cell lung cancer, with measurable disease on CT scan were evaluated. All patients were treated with conventional systemic chemotherapy, although the choice of chemotherapy was left to the discretion of the treating physicians. Serum samples were obtained immediately before the start of 1st and 2nd cycles of chemotherapy. CYFRA 21-1 was measured with an electrochemiluminescense immunoassay on an automatic analyzer （Elecsys 2000; Roche Diagnostics）. Response was evaluated using Response evaluation criteria in solid tumors （RECIST） criteria. Results： 10 patients had partial response, 9 patients had stable disease and 9 had progressive disease. None of the patients had complete response. 21/29 （72%） patients had an elevated baseline value of CYFRA 21-1.62% patients （18/29） had a decrease in CYFRA 21-1 after 1 cycle of chemotherapy. The average reduction in the 2nd reading was irrespective of whether baseline value was normal or not. The average reduction was statistically significant （P = 0.002; 95% CI, from 0.8369 to 3.49464; t test）. 8 out of 10 （80%） patients with partial response had a reduction in their 2nd reading of. CYFRA （P = 0.019; 95% CI, from 0.81965 to 7.20035; t test） which was significant. We also observed that 6/9 （66%） patients whose disease remains stable also had a decrease in their subsequent reading （P = 0.0106; 95% CI, from -0.44942 to 3.82720; t test）, though it was not significant statistically. Although 5 out of 9 （55%） patients, who had an increase in their CYFRA 21-1 level, had progressive disease, but it was not statistically significant （P = 0.537; 95% CI, from -1.20021 to 2.13354; ttest）. 14 out of 19 （73%） who either had partial response or had stable disease, had a reduction in their 2nd value of CYFRA 21-1 and was significant statistically （P = 0.004; 95% CI, from 0.74792 to 3.50208; t test）. We also observed that except for 1 patient, all patients who had a decrease of 42% or more in their subsequent CYFRA 21-1 level, were those who had either responded to chemotherapy or had stable disease （P = 0.001）, which was statistically significant. Conclusion： We can conclude that monitoring of serum marker CYFRA 21-1, early dudng first-line chemotherapy may be a useful prognostic tool for evaluation of early tumor response in patients with advanced NSCLC.

MiR-16-5p plays an inhibitory role in human non-small cell lung cancer through Fermitin family member 2

Increasing evidence indicates that aberrant expressions of some microRNAs are associated with cancer progression.However,the roles and biological mechanisms of miRNA-16-5p in human non-small cell lung cancer(NSCLC)are not to be well studied.Here,we validated that the expression of miR-16-5p was decreased significantly in NSCLC samples and cell lines.The correlation between the clinicopathological features of NSCLC and the miR-16-5p expression showed that the expression of miR-16-5p in non-small cell lung cancer was linked with the advanced TNM stage,positive lymph node metastasis,with short overall survival(OS).Also,a negative correlation between miR-16-5p and Fermitin family member 2(FERMT2)was observed,implying there may be a potential link about their regulation.The hypothesis was further confirmed by in-silico analysis and dual-luciferase reporter assay.Moreover,we demonstrated that the transfections of miR-16-5p mimics could alter some biological characteristics of NSCLC cells remarkably accomplished by the expression variance of FERMT2 in vitro and in vivo assays.Summarily,this study demonstrated that miR-16-5p,as a tumor suppression factor in NSCLC by targeting FERMT2,could serve as one promising biomarker in the prediction for NSCLC patients.

主应力方向和偏应力比对TJ-1模拟月壤各向异性的影响

采用空心圆柱扭剪仪对干燥TJ-1模拟月壤试样进行了应力主轴固定的定向剪切试验及不同偏应力比时主应力方向的纯旋转试验。从应力-应变关系角度出发,研究主应力方向、偏应力比对其各向异性的影响,并探讨了上述因素对TJ-1模拟月壤非共轴性的影响。试验结果表明:主应力方向和偏应力比对TJ-1模拟月壤的各向异性均有显著影响;应力主轴旋转引起的非共轴现象比定向剪切时明显,且偏应力比较小时非共轴角随应力主轴旋转呈先减小后增加的趋势,偏应力比较大时非共轴角一直减小直至试样破坏时非共轴现象消失。上述成果可弥补干砂试样非共轴领域的研究空白,并可望为将来月球上基础设施的修建提供技术支持。

桩-土水平相互作用的颗粒流数值研究

对水平载荷作用下的桩-土相互作用问题进行颗粒流数值模拟和研究.应用PFC2D程序,模拟了直线单调、直线循环、十字和半圆形加载路径下桩-土相互作用过程.并通过对加载过程中土的细观物理量的考察,研究土的细观力学特征和桩-土相互作用宏观力学行为之间的相互联系.研究结果表明,垂直方向的预加载会引起土阻力的退化,产生“垂向加载效应”;而在非直线加载路径下,随着位移的增加,载荷的增量方向会逐渐偏离位移的增量方向,出现不共轴的现象.数值试验观测到的现象和机理可为物理模型试验的进行提供积极的指导作用.

宏-细观结合的砂土单剪试验非共轴特性分析

针对传统本构理论无法描述土体单剪试验非共轴变形的不足,采用非共轴修正模型进行改进。模型基于材料状态相关临界状态理论,采用宏-细观结合的方法,将1个新的各向异性状态变量引入本构模型来描述砂土的各向异性。考虑细观组构张量和应力张量的几何关系的变化,模型可以描述砂土在主应力轴旋转条件下材料状态的变化,材料状态变化直接导致模型的硬化规律和剪胀性发生变化,因此,模型可以描述该条件下原生向异性对砂土变形的影响。引入非共轴理论对本构模型进行修正,建立了三维非共轴各向异性模型。单剪试验的加载条件会造成主应力轴相对土体沉积面发生旋转,修正模型不但能够描述砂土在主应力轴旋转条件下其原生各向异性对变形的影响,而且可以描述主应力轴旋转造成的应力诱发各向异性对土体变形的影响,因此,该模型能够对整个单剪试验的变形规律进行描述,而且物理意义清晰。通过铝棒堆积体和Toyoura砂单剪试验验证表明,非共轴修正各向异性模型能对单剪试验的整个变形过程进行较好的模拟。

竖向偏心荷载作用下吸力桶荷载-变形特性非共轴本构数值分析

在竖向偏心荷载作用下建立吸力式桶形基础数值分析模型,采用砂土非共轴弹塑性本构模型研究土体主应力方向旋转和非共轴角度的变化规律,探讨非共轴特性对吸力桶力学特性的影响.主要研究结论表明:在地基变形过程中,非共轴角度呈现先增大后减小的发展趋势.随着偏心距的增加,等效塑性应变在地基中的分布范围逐渐减小,非共轴特性也将减弱,非共轴特性对荷载-变形特性的影响逐渐减弱.对于桶壁端部阻力和桶壁外侧摩擦阻力,非共轴特性的影响随着偏心距的增加而减弱.对于桶体顶部阻力和桶壁内侧摩擦阻力,非共轴特性的影响随着偏心距的增加而逐渐显著.

考虑非共轴特性的吸力桶基础竖向荷载-变形特性研究

土体在剪切变形过程中会产生较为显著的主应力方向旋转,主应力方向与塑性主应变增量方向将呈现出显著的差异即非共轴现象.采用砂土非共轴弹塑性本构模型,以吸力式桶形基础为研究对象,研究土体主应力方向旋转和非共轴角度的变化规律,探讨非共轴特性对地基荷载-位移关系的影响.研究结果表明:在竖向荷载作用过程中,土体主应力方向处于单调旋转状态,吸力桶形基础高径比对土体主应力方向的旋转规律(方向、速率和极值)有显著影响.非共轴特性对荷载-位移关系的发展趋势有显著的减缓滞后作用,该作用在地基变形中期比较显著.随着高径比的增加,非共轴特性逐渐显著,该特性对地基竖向荷载-位移关系的影响逐渐明显.

基坑开挖过程中TJ-1模拟月壤变形特性的试验研究

采用空心圆柱扭剪仪对TJ-1模拟月壤试样进行基坑开挖应力路径的试验模拟,以研究地球重力场环境下TJ-1模拟月壤在地基开挖过程中的变形及非共轴特性。试验结果表明:应力路径对TJ-1模拟月壤的变形影响显著;开挖过程中坑底及连续墙外侧模拟月壤因变形过大而破坏,坑底位置土体受连续墙挤压的影响发生明显的剪缩现象;连续墙内外土体明显的非共轴现象是开挖所致偏应力、应力主轴转幅及旋转速率耦合作用的结果,且上述因素在不同位置影响程度也不相同,坑底位置以应力主轴的转幅及旋转速率的影响为主,基坑外侧则是偏应力比、转幅及旋转速率共同作用的结果。

应力幅值比对土-结构接触面非共轴特性影响研究

运用80 t大型三维多功能土工试验机(3DMAS),进行了不同应力幅值比下粗粒土与结构接触面大型三维循环直剪试验,深入分析了应力控制往返椭圆剪切路径下接触面切向位移、非共轴角和剪切柔度等三维力学特性以及应力幅值比的影响规律。应力控制往返椭圆剪切路径下,接触面产生了明显的x向和y向位移、非共轴角和剪切柔度。x向和y向位移幅值、剪切柔度峰值均随循环剪切的进行逐渐减小而后趋于稳定,表现出演化特性。非共轴角受切向应力幅值及切向应力增量方向共同影响,其最值、稳定值随循环周次基本保持不变;正向剪切时非共轴角最大值(最小值)与反向剪切时最小值(最大值)基本出现在同一位置。接触面剪切柔度与非共轴角随旋转角度的变化趋势相反,剪切柔度的增加会抑制非共轴角的发展,反之亦然,两者对立统一。应力幅值比对接触面切向位移间椭圆关系及其时程变化形式、切向应力位移类椭圆关系等影响较小,主要影响切向位移幅值及其偏移程度、切向位移间椭圆关系的长短轴大小及方向、切向应力位移类椭圆关系的长短轴大小、非共轴角的数值及其随旋转角度的变化形式和最值出现位置、剪切柔度随旋转角度的变化形式和峰值及其产生位置等。应力幅值比越大,切向位移幅值越大、向负向偏移越大,剪切柔度峰值越大,随循环剪切的进行减小的速率越慢。应力幅值比ξτ=1和ξτ≠1时接触面非共轴角和剪切柔度随旋转角度的发展变化形式差别很大。

干密度对定向剪切下重塑黄土力学特性影响研究

为研究不同干密度对定向剪切下重塑黄土力学特性的影响,采用英国GDS空心圆柱扭剪仪(HCA)对青海重塑黄土进行一系列定向剪切试验。试验保持平均主应力、中主应力系数和大主应力方向角不变,重点探讨干密度的变化对定向剪切条件下重塑黄土强度和变形的影响。试验结果表明:重塑黄土在定向剪切路径下破坏强度随着干密度的增大而增大;重塑黄土的八面体剪应变和主应变的开展模式受到初始干密度的显著影响;重塑黄土的归一化强度随干密度的增大呈现出近似线性增长的趋势;重塑黄土在剪切破坏后期的大主应力方向和应变方向不一致,存在明显的非共轴现象;在干密度为1.72 g/cm^(3)时,重塑黄土剪切破坏时的非共轴角超过12°。

浅基础地基荷载-变形特性的分析研究

在土体主应力方向的旋转过程中,主应力方向与塑性主应变增量方向之间存在着非共轴现象,非共轴现象对应力-应变关系具有显著的影响。通过有限元二次开发,将角点结构非共轴理论应用到有限元程序ABAQUS中;对密砂单剪试验进行数值模拟,研究了非共轴现象及其对应力-应变关系的影响;采用离心模型试验方法,对圆形浅基础作用下饱和密砂地基荷载-变形特性进行试验研究;对离心模型试验进行数值模拟,将试验结果与数值计算结果进行对比,对非共轴模型的计算结果的合理性进行验证。研究结果表明:非共轴现象对浅基础地基荷载-变形特性具有显著的影响;当选取合理的非共轴塑性模量时,非共轴模型的计算结果与离心模型试验结果比较接近。

偏心荷载作用下条形浅基础荷载-变形特性数值分析

在主应力方向的旋转过程中,主应力方向与塑性主应变增量方向之间存在着非共轴现象。基于屈服角点结构非共轴理论,建立了一种非共轴本构模型,通过有限元软件ABAQUS的二次开发子程序UMAT,将该模型运用到有限元数值计算中。首先,对中密砂单剪试验进行数值模拟,研究了非共轴现象及其对应力-应变关系的影响。然后,针对偏心荷载作用下条形浅基础荷载-变形特性进行数值分析,研究了非共轴现象对荷载-位移关系的影响。研究结果表明:非共轴模型计算得到的荷载增长速度滞后于共轴模型计算结果的增长速度;在地基变形的初期,非共轴现象比较明显,主应力方向的减小速度要滞后于塑性主应变增量方向的减小速度;随着地基沉降的增加,非共轴现象逐渐减弱;非共轴模型与共轴模型计算结果之间的差异在应变硬化情况下更加明显。

非标准波导-同轴电缆转换组件的研制

介绍了非标准波导-同轴电缆转换组件的设计及Ansoft HFSS仿真。详细阐述了将电缆内导体直接插入同轴谐振腔内进行调配,通过改变短路活塞在波导谐振腔内的位置和λ0/4同轴调谐器在同轴谐振腔内的位置,可实现小电压驻波比、低损耗、结构稳定可靠等优异的技术性能,并给出了实测数据,其主要技术性能优于俄罗斯同类产品的主要技术性能。

矢量网络分析仪非同轴测量的TRL校准件设计制作

矢量网络分析仪在非同轴和高频率条件下难以实现理想的匹配负载,但通过TRL校准可降低参数要求,且精度较高。因此,本文对TRL校准技术的原理和设计原则进行介绍。以HDMI线缆测量为例,对非同轴测量TRL校准的全部环节进行论述,包括设计方法、性能验证和测量试验,为相关技术研究提供参考。