陇海线路巉口镇K1642+680～+800段袖阀管注浆加固性能研究

本文以陇海线路巉口镇K1642+680～+800段袖阀管注浆加固工程为依托,基于现场治理方案设计分析,通过现场轻型动力触探试验研究,结合现场行车加速度响应实测分析,对袖阀管注浆加固性能进行评价,得到了以下结论:①袖阀管加固区域其浆液与土体凝结,增加了土体的密实度,导致加固区域的土体对振动波吸收较少,其加速度响应情况明显要大于未加固区域各测点的加速度响应情况,间接表明袖阀管注浆方式对铁路路堤的加固起到了良好地作用。②袖阀管注浆加固土体的密实度和承载力随着土体深度的增加而增加,且随着深度增加,土体的承载力变化较大,特别是深度范围在180cm-210cm范围内土体承载力显著增大。     

轻型圆锥动力触探在国外某电源工程验槽中的应用

文章介绍了美国材料与试验协会ASTM标准下的轻型圆锥动力触探试验在国外某电源项目工程基槽检验中的应用,通过试验分析,应用轻型圆锥动力触探试验检测天然地基承载力是否满足设计要求在该区域取得了良好的效果,为国内同行从事类似工程提供参考。     

试论路基施工中软基的诊断与控制措施

在公路路基建筑施工中软基是多数项目面对的难题。而使用轻型触探仪诊断软基是施工中比较方便快捷的方法。在开沟清表的第五个晴天,做了现场测试地基,当满足cu≥25kPa时,即为软土深度,软基探测每断面间距10m,布置5个测点,或以5m×5m方格网"十"字角点作为触点。     

水泥粉煤灰搅拌桩加固饱和黄土地基现场试验研究

随着高速公路建设的飞速发展,在完善原有地基处理技术的同时,新的地基处理方法也不断涌现出来。本文以渭蒲高速公路饱和黄土地基处理课题为背景展开工作,针对该路段饱和黄土的工程性质,提出了用水泥粉煤灰搅拌桩处理饱和黄土,并选择地质条件和填筑高度都有代表性的地段进行现场试验。成桩后,采用浅部开挖桩头、现场抽芯无侧限抗压强度试验、轻型动力触探(N10)三种方法对地基处理效果进行检测,通过分析检测结果进一步优化依托工程地基处理方案的各项工艺参数,用以指导大规模地基处理施工的开展。     

不同萃取剂对分离甲基叔丁基醚-甲醇的研究

实验以非质子极性有机溶剂二甲基亚砜、N,N-二甲基乙酰胺、N,N-二甲基甲酰胺、1,2-丙二醇作为萃取剂,通过气液平衡装置以共沸体系甲基叔丁基醚-甲醇为待分离物系,考察单一溶剂在同一溶剂比下的分离效果、选取最佳溶剂,观察同一溶剂在不同溶剂比下的分离效果。结果表明:相对挥发度为DMSO>DMF>DMAC>1,2-丙二醇,则DMSO为最佳溶剂;溶剂的分离性能随着溶剂比的增大而增大;甲醇作为一种良好的质子供体,和电子供体的溶剂形成氢键缔合,由此改变甲基叔丁基醚在甲醇中的活度系数,增大甲基叔丁基醚对甲醇的相对挥发度。     

强夯法与振冲法相结合在黄河冲积平原某工程中的应用分析

文章简要介绍了黄河冲积平原的沉积物特征,以及存在的主要工程地质问题之一——饱和砂土的振动液化,并引例分析了强夯法与振冲法相结合消除饱和砂土振动液化的应用。强夯法增强了地基强度,提高了地基承载力;振冲法增强了砂土的密实度。强夯法与振冲法相结合进行地基处理,消除了饱和砂土的液化沉陷,二者结合作用非常显著。     

矿物微粉对水泥基混合料抗压强度的影响

为了了解矿物微粉对混凝土性能的影响,利用可压缩堆积模型(CPM)计算了不同体系胶凝材料的堆积密实度,研究了矿物微粉级配及其相对掺量对低水胶比水泥基混合料抗压强度的影响。结果表明,胶凝材料的堆积密实度与水泥基混合料的抗压强度有很强的对应关系;当堆积密实度相差不大而化学效应相差较大时,化学效应越大,抗压强度越大。     

压实黄土性状的室内试验研究

通过室内试验研究了压实黄土的变形、强度特性。从击实黄土的室内三轴压缩试验可以得出,随着压实度K的增大,压实黄土的内聚力c增大很多,而内摩擦角φ的增大幅度相对较小。通过双线法得出不同压实程度(干密度)下的压力与湿陷系数关系图可以看出,击实黄土在击实不充分的情况下仍具有湿陷性。若以200KPa下的湿陷系数为0.015为评判标准,所用土样干密度小于1.62g/cm3对应压实度小于95%时具有湿陷性。     

水泥稳定碎石基层振动成型理论分析与施工中的质量控制

振动成型法的压实原理与现有实际施工振动压路机的压实原理相近,它是集压实与振动于一体,使集料内的颗粒产生相对位移和流动并压实,集料的嵌挤更为密实,空隙率更低,密实度相对重型击实法更高。文章论述了施工质量形成的施工工序,其中原材料、配合比设计、试验段及常规施工的质量的综合体形成了最终工程质量。     

论强夯法在济邵高速公路路基施工中的应用

强夯指的是为提高软弱地基的承裁力,用重锤自一定高度下落夯击土层使地基迅速目结的方法.利用起吊设备,将10～25吨的重锤提升至10～25米高处使其自由下落,依靠强大的夯击能和冲击波作用夯实土层.强夯法主要用于砂性土、非饱和粘性土与杂填土地基.对非饱和的粘性土地基,一般采用连续夯击或分遍间歇夯击的方法;并根据工程需要通过现场试验以确定夯实次数和有效夯实深度.现有经验表明:在100～200吨米务实能量下.一般可获得3～6米的有效务实深度.结合工程实饲介绍了高速公路路基填筑施工中强夯法的施工工艺、施工设计及强夯质量控制要点.     

Economic growth,volatility and their interaction: What’s the role of finance?

This paper examines the relation between financial depth and the interaction of economic growth and its volatility. We use a sample of 52 countries for the period 1980–2011, and our main finding is that, at moderate levels of financial depth, further deepening increases the ratio of average growth to volatility; however, as financial depth increases, this relation reverts, and the rise in volatility overcomes that of economic growth. This result is obtained both in the medium and long run; however, the peak of the relation seems to be lower in the medium run (around 40%–55% of domestic credit/GDP) than in the long run (around 75%–99%). This suggests that increasing the level of domestic credit may intensify relative volatility in the medium term, but still raise relative long-term growth before the long-run threshold is achieved.     

不同岩性尾矿砂混凝土性能的研究

分析超贫钒钛磁铁矿、片麻岩、矽卡岩的尾矿砂成分,研究分析不同岩性尾矿砂混凝土的抗压强度、抗渗性能、抗冻性能、碳化性能。试验结果表明:不同岩性尾矿石粉在体系中可能充当胶结的作用,可提高混凝土抗压强度;试验对比了抗氯离子试验,得出超贫钒钛磁铁矿砂混凝土的抗氯离子渗透性能最优;C30强度等级的各组混凝土可满足F150抗冻等级的要求,C50强度等级的各组混凝抗冻等级可达到F300的要求;不同岩性尾矿砂混凝土试件的碳化深度主要受微孔结构密实程度的影响,只要配制的混凝土级配合理、密实度良好,一般细集料对混凝土碳化性能没有影响。研究成果可为不同岩性尾矿砂混凝土的深入研究和实际工程应用提供参考。     

轻便动力触探在工程建设地质验槽中的应用与实践

在施工过程中,为了提高施工质量,需要对地基土壤与工程地质等进行检测,本文通过阐述基槽的验收内容,分析钎探的实践与应用,同时提出相应的政策建议,在工程建设中为应用轻便动力触探提供参考依据。     

LOCATION OF VERTICALLY LINKED OLIGOPOLISTS

This paper examines the geographical equilibrium of location of N vertically linked firms and its relation to the creation of an industrial cluster. In a two-region spatial economy, a monopolist firm supplies an input to N consumer goods firms that compete in quantities. When the transport cost of the input increases, downstream firms prefer to agglomerate where the upstream firm is located, to save in production cost. However, simultaneous increases in the transport cost of the input and of the consumer good or increases in the number of downstream firms lead to a relative dispersion of these firms, to reduce competition and locate closer to the local final consumer. In contrast to Mayer (2000) , when both transport costs increase, the location decision of downstream firms is based more on the geographical point that maximizes accessibility to the local final consumer than on the geographical point that minimizes the production cost.     

开放条件下中国货币与经济关联度变动原因实证研究

本文运用动态条件相关(DCC)方法估计中国各层次货币与实体经济的关联度。研究发现,1994年前,关联度始终在低位波动,之后大幅提高,总体呈上升趋势。通过在模型中引入金融深化度和经济开放度,本文从不同的侧面解释了货币与经济关联度变动的原因。虽然金融深化度和经济开放度对关联度的影响程度随货币层次的提高而增强,但作用方向却不完全相同;金融深化度越高,经济开放度越低,关联度越强,这表明金融深化理论与中国国情相适应。这对于改革开放具有较强的现实意义。政府通过优先发展金融,深化金融体制改革,能够提高货币对经济增长的效能,促进经济结构的转型和经济持续增长。     

三极测深的研究与应用

在电测深工作中,常常遇到悬崖、河流等复杂地形条件限制,无法应用对称四极电测深法。但三极电测深法将其中的一个供电极放于无穷远,另一个电极移动,这样大大增强了跑极的灵活性,因此在有限的复杂地形中,经常采用三极电测深法。本文通过理论模型研究和实际应用效果得出,三极电测深和四极电测深对比,异常中心无偏移,能探测出了异常体的位置和深度。     

Mathematical models describing the effects of different tax evasion behaviors

Microscopic models describing a whole of economic interactions in a closed society are considered. The presence of a tax system combined with a redistribution process is taken into account, as well as the occurrence of tax evasion. In particular, the existence is postulated, in relation to the level of evasion, of different individual taxpayer behaviors. The effects of the mentioned different behaviors on shape and features of the emerging income distribution profile are investigated qualitatively and quantitatively. Numerical solutions show that the Gini inequality index of the total population increases when the evasion level is higher, but does not depend significantly on the evasion spread. For fixed spread, the relative difference between the average incomes of the worst evaders and honest taxpayers increases approximately as a quadratic function of the evasion level.     

淤泥软土地基处理探析

目前,软土地基处理的方法有预压法、换填法、强夯法和强夯置换法、砂石桩法、水泥土搅拌法及其他地基处理法。本文着重介绍各个方法的施工工艺及流程,然后对于相同地质条件的软土地基提出相应的处理措施,剖析地基处理的重点,最后根据处理结果选择合适的处理方案。     

Risk aversion,public disclosure,and partially informed outsiders

In this paper, we examine the impact of public disclosure and partially informed outsiders on a risk-averse insider’s trading behavior, market efficiency, and market depth. In our model, under disclosure requirements, except for the final auction, market depth is the same at every auction. When informed outsiders are risk-neutral, in contrast to the case of a risk-averse insider with no informed outsiders, the insider is more concerned about the uncertainty about future price risk. When the number of informed outsiders increases, market liquidity improves, and the insider increases the variance of her random component to conceal her trading strategy. However, since the insider is relatively more risk-averse, she pays less attention to doing this on her own. Besides, the order flow provided by informed outsiders and randomly added by the insider injects additional liquidity into the market. When informed outsiders are risk-averse, compared to risk-neutral informed outsiders, an insider is most concerned about trading risks brought by informed outsiders at the beginning of trading. Furthermore, whether the trader is an insider or informed outsider, the more risk-averse trader has lower expected profits. Moreover, outsiders’ greater risk aversion leads to a smaller market depth.