砼路面早期裂缝的防治对策

水泥混凝土路面早期裂缝的成因错综复杂,只要保证基层施工质量,严把材料质量关,严格控制配合比和水灰比,加强混凝土养生,及时切缝,同时,以人为核心,以预防为主,牢固树立"质量第一"的观念,科学组织,精心施工,严格管理,层层把好质量关,水     

连续配筋混凝土路面荷载应力的分析

1、概述为了减少接缝水泥混凝土路面由于横向胀、缩缝的薄弱而引起的各种病害(如唧泥、错台等),改善路用性能,延长道路的使用寿命,在高等级公路的特殊地段采用连续配筋混凝土路面(简称CRCP)是一种合理的路面结构形式。CRCP由于在路面纵向配有足够数量的钢筋,以控制混凝土路面板纵向收缩产生的裂缝宽度和数量,在施工时完全不设胀、缩缝(施工缝及构造所需的胀缝除外),为道路使用者提供了一条完整而平坦的行车表面,既改善了汽车行驶的平稳性,同时又增加了路面板的整体强度。     

路桥灌缝混凝土强度检测鉴定的分析

随着机动车辆的增加,在我国很多的路桥当中出现裂缝现象,给车辆的出行带来不变,混凝土是现阶段路桥当中的主要材料,因此在对路桥灌缝的时候,对于混凝土强度的鉴定就显得非常必要。文章分析了路桥灌缝的类型,重点探讨了路桥灌缝混凝土强度的检测与鉴定方法及原则。     

浅谈水泥混凝土路面施工中缝的设置

随着西部大开发的不断深入,为解决广大农村方便出行,在2007年,贵州省在遵义革命老区首次推行通村油（混凝土）路,弹石路面试点工程,我县在2007年度76公里通村油（混凝土）路施工过程中,由于施工任务紧、时间段,对部分路段各种缝的设置未引起重视,导致后期出现因缝的设置不规范而造成水泥混凝土路面有裂缝、断板、碎板现象,因此,我们在施工水泥混凝土路面时,除了对各道工序严格要求外,更应该重视各种缝的规范设置。     

浅谈在混凝土路面施工中如何设置缝

随着西部大开发的不断深入,为解决广大农村方便出行,在2007年,贵州省在遵义革命老区首次推行通村油（混凝土）路,弹石路面试点工程,我县在2007年度76公里通村油（混凝土）路施工过程中,由于施工任务紧、时间段,对部分路段各种缝的设置未引起重视,导致后期出现因缝的设置不规范而造成水泥混凝土路面有裂缝、断板、碎板现象,因此,     

JH区块沙溪庙组致密砂岩气藏压裂缝高影响规律研究

致密砂岩油气作为非常规油气资源之一,已成为油气增储上产的“重点领域”与“亮点类型”。其中四川盆地JH区块沙溪庙组致密气资源丰富,河道砂体广泛发育,开发潜力巨大。致密砂岩气藏低孔低渗的特性决定了只有采用水平井分段压裂才能实现其规模效益开发,而在水力压裂过程中,裂缝高度控制是一件很棘手的问题。基于此,以JH区块为研究背景,建立三维层状介质压裂数值模拟模型,以现场压裂施工数据和井温测井缝高数据为基础,优选P3D裂缝扩展模型,进而分析工程、地质因素对裂缝垂向扩展行为的影响和控制作用。研究结果表明,不可控地质因素中储隔层应力差是影响裂缝高度的最关键因素,当储隔层最小水平主应力差达4～6 MPa后,裂缝几乎不会发生穿层;杨氏模量影响较小,泊松比几乎没影响;可控工程因素中施工排量和压裂液黏度对缝高影响较大,低排量和低黏度有助于控制缝高。     

水泥混凝土路面产生裂缝中的施工因素研究

水泥混凝土路面产生的不规例的断缝（断板）是道路工程中最难解决的问题。本文将重点从施工角度分析产生裂缝的原因，希望对水泥混凝土道路的建设有一定的借鉴。     

水泥混凝土路面裂缝原因及防治措施

简要地叙述了水泥混凝土路面在施工中容易出现的病害,分析了混凝土路面的不规则微裂缝、路面通缝、路面跑砂、起皮等质量通病的原因,并论述了施工中采取的应对措施,确保路面工程质量.     

阳春沟构造带页岩裂缝发育特征及对产能的影响

以渝东南地区阳春沟构造带上奥陶统五峰组-下志留统龙马溪组页岩为研究对象,通过岩心观察、成像测井解释(FMI)、薄片鉴定、氩离子抛光扫描电镜等手段,深入分析并探讨了页岩裂缝的发育特征及其对页岩气成藏和开发的影响.结果表明:阳春沟构造带五峰组-龙马溪组页岩发育大量裂缝,宏观裂缝以构造缝为主,包括高角度剪切缝、低角度滑脱缝,非构造缝主要为层理缝和层间缝;微裂缝主要为层间缝、粒间缝、粒内缝.天然裂缝的发育对页岩气成藏和开发有着重要的控制作用.首先影响页岩气的储集与保存.天然裂缝能够增加页岩的储集空间,但大型天然开启裂缝可能破坏上覆层的封闭性,造成天然气散失,不利于页岩气成藏.其次影响后期人工体积改造的效果.被方解石充填的裂缝网络有利于水力压裂;但大型天然开启裂缝的发育会导致钻井液大量漏失,同时也不利于后期压裂改造形成复杂缝网.     

水利大坝混凝土施工质量控制措施

水利大坝混凝土属于大体积混凝土,其质量通病通常有:施工冷缝、泌水现象、表面水泥浆过厚、早期温度裂缝等几种类型。其施工质量控制的关键在于配合比设计控制、原材料质量控制、施工过程质量控制以及温度控制等几方面。     

Penetration and Post-infection Development of Meloidogyne Incognita on Tobacco as Treated by Rhizobacteria Pseudomonas Fluorescens Strain P-72-10

The bio-control potential of rhizospere bacteria Pseudomonas fluorescens against plant-parasite nematode had been demonstrated. P. fluorescens had shown the effect to enhance tobacco resistance to root-knot nematode Meloidogyne incognita. Inoculation with P. fluoreseens in tobacco could lead to significant reductions in the number of juveniles that penetrated tobacco root and further life stage development of the juveniles. The number of juveniles penetrated into tobac- co root in treatment with P. fluorescens is significantly different from CK at 2DAI, 6DAI, 8DAI and 10DAI. Significant reduction and delayed development of juveniles that penetrated into tobacco root and treated were observed in treatment at 14DAI, 21DAI, 28DAI and 35DAI. In addition, P. fluoreseens treatment leads to a significant reduction in the number of eggs per egg-mass at 35 DAI. The results show P. fluorescens induced a continuously suppression on root-knot nema- tode M. incognita throughout their entire early infection phase of root penetration, subsequent life stage development and reproduction.     

On the Major Transformation of the Asia-Pacific Regional Structure北大核心CSSCISSCI

Recent years have witnessedsignificant changes in the Asia-Pacific regionalstructure featuring the shift in power balance among related countries as well as adjust-ments in their respective regional strategies. So what is the prevailing trend in thistransformation and what kind of regional order will likely emerge in the future？ To an-swer these questions, the paper tries to explore the following dimensions： the evolvingregional context, shift in power balance and power conversion, geo-political and geo-e-conomic developments and interactions between them, and evolving regional order. Asthe study shows, the broadening of regional geographical scope, the rise in the numberof actors involved, as well as changesin the relations among them, have combined tocast a pluralistic and complex flavor to the regional structure. While the power balanceamong China, the United States and Japan shifts, and power conversion is also occur-ring. China and Japan are paying increasing attention to their security roles, whereasthe United States under the Obama administration laid more stress on expanding itsgeo-economic clout. In spite of the intensifying geopolitical competition among China,the United States and Japan in recent years, a Sino-US strategic compromise-whichholds the key to regional geopolitics-isother front, some kind of geo-economicmore likely to take place in the future. On thecooperation will probably emerge. In the longerterm, it will be the geo-economic trend thatwill prevail over the geopolitical trend inthe region. Finally, the future evolution of regional order wiI1 mainly follow the eco-nomic logic, accompanied by the dilutionof its hegemonic and hierarchical nature.Hence, a pluralistic and complex regional community will emerge.     

The German Hanse and Bergen – new perspectives on an old subject

Abstract

The Hanseatic League and her kontors (trading posts) were an integral part of the medieval trade system in Northern Europe. Hanse merchants dominated many markets in this region and managed to maintain a monopoly-like role in towns like Novgorod and Bergen for many centuries. Consequently, one focus of historical research about the Hanseatic League lay on the mechanisms that enabled the Hanse merchants to keep that strong of a position for such a long time.

This article is part of the discussion about this topic. Based on Lübeck merchants with business interest in the Norwegian town of Bergen, the so-called Bergenfahrers (Bergen travellers), it will give new insights into the Hansards' economical and social organization. The three main points are (a) the integration of the Bergen market in the Hanseatic trade network as an intermediary trading place on the vivid East–West route of Hanse trade; (b) the importance of the Bergenfahrers within the Hanse merchants' economical, social and political networks; and (c) the structure of the Bergenfahrers network patterns in the late Middle Ages.

In addition to new insights into the important role of Bergen and the Bergenfahrers within Lübeck's and the other Wendish Hanse towns' trading system, this articles provides further proof for the usefulness of the methods of Social Network Analysis in medieval economic research.     

Organization and incentives in the age of sail

The British Navy in the age of sail was the most successful bureaucracy of its time. Its organization and incentive structures differed importantly from contemporaneous private sailing ventures, but closely resembled those of today’s large corporations. To induce efficient effort, the navy used a hierarchical tournament, in which sailors competed for higher pay that came with promotions based on relative performance. Promotion probabilities, the option value of future promotions, and the higher effort required of men in higher ranks and on larger vessels, combined to yield a highly skewed pay structure.     

For Better or for Worse? Local Impacts of the Decentralization of Indonesia’s Forest Sector

This paper quantifies the local impacts of mechanized logging on forest-dependent communities in Indonesia, before and after decentralization. A conceptual framework incorporates financial, social, enforcement, rent-seeking, and environmental impacts. Using data from 60 communities in East Kalimantan, the empirical results suggest that significantly more households received financial and in-kind benefits after decentralization compared to before. Many communities engaged in self-enforcement activities against firms both before and after decentralization. Post-decentralization, a significantly higher proportion of households perceived community forest ownership. There were few significant differences in perceived environmental impacts. Little evidence exists of a post-decentralization trade-off between environmental and financial contractual provisions.     

以资本管理为核心的银行治理综合评价指标研究

商业银行的特殊性体现在风险性、外部性和多重治理目标上，尤其集中体现在风险管理的本质上。风险管理日益成为现代商业银行的主体活动和核心职能，资本管理成为现代商业银行风险管理的核心。在整合EVA和RAROC指标的基础上。文章构建了以资本管理为核心的银行治理的综合评价指标，以求真实反映银行经营的成果，有效衡量风险收益和风险成本的对比关系，从而反映以资本管理为核心的银行风险管理的过程、能力和效率。     

Financial Reporting and Trade Credit: Evidence from Mandatory IFRS Adoption*

We investigate the effect of mandatory IFRS adoption on trade credit. We document that firms in countries that adopt IFRS receive more trade credit from their suppliers, consistent with improved financial reporting quality and comparability playing a role in facilitating informal financing. This increase is larger for countries with a low level of societal trust, a poor pre‐IFRS‐adoption information environment, and stronger legal enforcement. These cross‐sectional results suggest that the conditions under which higher‐quality information is made publicly available affect suppliers' decisions to provide trade credit. This increase is also larger for firms with greater exposure to foreign markets, a finding that highlights the importance of more comparable international financial reporting standards in facilitating cross‐country trade credit. We also find that IFRS adoption has a stronger positive effect on trade credit for firms with greater liquidity needs. Finally, we find that firms in countries that adopt IFRS also extend more trade credit to their customers. Overall, our results support the notion that financial reporting can have a causal effect on trade credit.     

Markteintrittstiming von Telekommunikationsdiensteanbietern

Zusammenfassung Die vorliegende Studie analysiert für 87 Neuprodukteinführungen (NPE) und Auslandsmarkteintritte (AME) von Telekommunikations(TK)-Diensteanbietern in Deutschland, zu denen 42 Schlüsselinformanten in einer schriftlichen Befragung Auskunft gaben, (1) inwieweit deren zeitliche Eintrittspositionierung durch Marktcharakteristika und Unternehmensressourcen erkl?rbar ist sowie (2) inwieweit und gegebenenfalls unter welchen unternehmensexternen und -internen Situationsbedingungen deren Markteintrittstiming mit dem wahrgenommenen Eintrittserfolg assoziiert ist. Ein früher Markteintritt wurde dann realisiert, wenn die Wettbewerbsintensit?t im adressierten Gesch?ft niedrig und das Budget für den Expansionsschritt überdurchschnittlich ausfielen. Zwischen dem Markteintrittstiming und der Beurteilung des Eintrittserfolgs bestand ein nicht monotoner, umgekehrt U-f?rmiger Zusammenhang: Frühe Folger wiesen signifikant bessere Erfolgswerte auf als Pioniere und sp?te Folger, deren Erfolgsniveaus nicht signifikant divergierten. In einer Industrie, die durch starke externe Netzeffekte gepr?gt ist, fallen offenbar die Nachteile eines Markteintritts als Pionier oder sp?ter Folger st?rker ins Gewicht als die Vorteile dieser beiden zeitlichen Eintrittspositionierungen. Unabh?ngig vom Markteintrittstiming wurden NPE/AME von TK-Unternehmen als erfolgreicher eingestuft, wenn sie sich in einen Markt mit stark wachsender Nachfrage und aufeinander abgestimmt (re)agierenden Wettbewerbern mit qualitativ überdurchschnittlichen, abw?rtskompatiblen, erprobbaren und wenig erkl?rungsbedürftigen TK-Diensten engagierten.