井下动水注浆技术与方法研究

在井下施工堵水钻孔,用骨料器和地面注浆系统,动水封堵井下出水点。该方法有工程量小、费用低、堵水率高、工期短等特点,不仅改善生产环境,而且创造良好的经济效益。     

底板穿层入煤顺层定向长钻孔在矿井煤巷条带瓦斯治理中的应用

为满足顺煤层定向长钻孔煤巷条带消突的需要,结合不具备揭煤条件的实际情况,研究从底板穿层入煤然后顺层定向成孔的施工方法,覆盖煤巷条带区域,实现区域瓦斯治理。本文通过分析10煤底板及10煤地层特征,研究并改进井下定向长钻孔成孔工艺方法,利用新的钻具组合和无固相冲洗液,进一步提高了液动定向钻进在松软煤层中的成孔能力。优化钻孔结构,有效改善岩孔段堵渣现象,完成了380m底板穿层入煤顺层定向长钻孔施工,实现了区域瓦斯抽采治理。     

富含水层煤层原始瓦斯压力的测定

富含水层煤层原始瓦斯压力测压过程中,常常遇到钻孔积水问题,导致难以测定真实有效地煤层原始瓦斯压力.在洛阳龙门煤业原始瓦斯压力测定具体条件下,本文通过注浆堵水、集水器排水措施有效地解决了钻孔积水对原始瓦斯压力测定带来的不利影响.通过释放钻孔中积水,准确的测定出了该矿煤层原始瓦斯压力.     

煤层底板注浆加固定向孔钻进工艺及装备研究

注浆加固技术在煤矿开采中十分有效,利用该技术能有效改造煤层底板。由于一般钻孔方式效果较差,要加强底板注浆固定定向钻进工艺设备的使用,结合案例总结技术和设备使用方法。     

复杂地质条件下钻孔突水发生机理、危害及处理措施

河南煤业化工集团鹤煤公司第十煤矿地质条件相对较复杂,常有煤层底板开裂、突水或底鼓等地质现象发生.为了避免回采过程中出现安全事故,矿井决定对煤层的底板进行改造.底板改造实施过程中,发现在某些地质条件复杂的区域钻孔时,极易出现钻孔突水的事故.对此,鹤煤十矿制定了行之有效的实施方案,提出相应的技术路线,并对提出的治理措施的可行性进行了论证.     

高突低透煤层区域瓦斯综合治理技术应用研究

某矿为煤与瓦斯严重突出矿井,104工作面为该矿的首采保护层工作面,结合煤层的赋存及瓦斯灾害情况,该工作面采取底板岩巷穿层钻孔预抽煤巷条带煤层瓦斯结合顺层钻孔预抽回采区域煤层瓦斯的区域防突措施.试验结果表明,104工作面开切眼前方100～400m范围煤层残余瓦斯压力实测最大值为0.33MPa,分别根据残余瓦斯压力和瓦斯抽采量计算的残余瓦斯含量为4.36m3/t、3.58m3/t,均低于《防突规定》的临界值,表明通过实施底板岩巷穿层钻孔结合顺层钻孔预抽煤层瓦斯的区域防突措施,该区段煤层已完全消除煤与瓦斯突出危险性.     

底板穿层钻孔在月亮田矿21124采面掘进区域防突中的应用

主要介绍月亮田矿21124综采工作面(首采层)底板穿层钻孔在该工作面掘进期间的区域防突、瓦斯治理及取得的成功经验。     

采掘影响下巷道底板变形破坏特征研究

煤矿采掘引起底板岩层变形破坏是矿井突水的主要因素之一,为探究特殊地质构造条件下巷道掘进过程中底板变形破坏特征,以裴沟煤矿31151回风巷底抽巷为工程背景,基于钻孔成像窥视监测技术和FLAC^3D软件平台下构建地质体Mohr-Coulomb本构数值模型,对比分析岩层结构变化情况确定底板受掘进影响的程度,发现底板变形破坏深度约3.9m,底板次生裂隙是水位变化的主要影响因素,底板垂直应力在掘进6～10m位置时最大,应力值达到0.74～0.96MPa,竖直位移在掘进0～8m时随距离增加逐渐增加,掘进10m后底板垂直应力和竖直位移明显降低。     

新安煤矿快速水力冲孔工艺装备技术研究

目前,我国在对底板岩巷穿层钻孔进行水力冲孔时,多逐次逐个对钻孔进行冲孔,该方法在应对大批量钻孔冲孔时占用时间过多。为提高穿层钻孔的冲孔效率,新安煤矿在14200工作面进行了快速水力冲孔技术试验,该技术在保证穿层钻孔煤孔段冲出煤量1t/m的前提下,可实现单批次同时对5个穿层钻孔进行冲孔增透,且单批次冲孔时间在2h～4h。经现场应用,快速水力冲孔技术具有明显的高效性,并能为后期穿层钻孔瓦斯的抽采提供充足的时间。     

近距离煤层群上保护层开采瓦斯治理技术实践

为了解决近距离煤层群上保护层工作面瓦斯治理难题,在沿空留巷Y型通风的基础上,采取底板定向长钻孔抽采、顶板高位定向长钻孔抽采、采空区揉膜墙压管抽采、本煤层钻孔抽采等瓦斯综合抽采技术。实践表明,采取上述抽采措施后,工作面瓦斯抽采率达到54.68%,回采期间,回风流瓦斯浓度保持在0.3%～0.5%左右,瓦斯治理效果显著。     

橡胶内衬储罐制造质量控制要点

橡胶衬里对现场制作的储罐有一些特殊要求,在储罐制造中若控制不当会出现变形过大、焊缝严重咬边及成型不合格等问题而无法衬胶。总结了承建的某离子膜烧碱项目中衬胶储罐制造经验,对材料验收、基础交接、储罐预制、组对、焊接、后处理等主要环节的质量控制要点进行了详细的阐述。主要包括：在预制前全面掌握衬胶对储罐的质量要求;合理安排焊接顺序,控制罐底板焊接变形;采取加固措施,防止底板与壁板角焊缝焊接产生的底板变形;精细计算罐顶板尺寸,控制预制下料及组对偏差;制定最佳焊接工艺,控制壁板焊接变形等。通过上述各项措施的实施,最终达到了提高制造质量,减少后处理工作量的目的。     

钢结构常压方形储罐单片制作质量控制

在大型储罐的制作安装过程中,由于大型储罐面板面积大,板较薄,包含焊缝数量多,焊缝较长,排布方式多样,若控制措施不当,很容易引起变形;焊接变形产生的原因主要是因为焊接产生的热量在焊接件上的不均匀分布造成的。如何有效地控制罐壁板和上下底板的变形,是制作的难点和重点。从焊接产生的热量和焊接应力两个方面分析了钢结构方形储罐单片制作过程中的焊接变形原因,描述了焊接变形控制的4个常用方法,并针对钢结构方形储罐单片制作过程中的焊接变形提出了质量控制方法。     

Corporate Governance and returns on information technology investment: evidence from an emerging market

Prior studies have reported mixed findings on the impact of corporate information technology (IT) investment on firm performance. This study investigates the effect of corporate governance, an important management control mechanism, on the relation between IT investment and firm performance in the Taiwanese electronics industry. Specifically, we explore board independence and foreign ownership, which have increasingly become salient factors concerning corporate governance in emerging markets. We address their roles across firms of different sizes and in industries where degrees of competitiveness run a wide gamut. Our results show a positive moderating effect of board independence on the IT investment‐firm performance relation, especially when competition intensifies. Furthermore, we find that the greater the foreign ownership in small firms, the more positive the IT investment‐firm performance relation, suggesting that foreign investors may bring IT expertise to help small firms reap the benefits of using IT. Copyright © 2010 John Wiley & Sons, Ltd.     

松软特厚煤层9.5m大断面切眼支护技术研究

内蒙古蒙泰不连沟煤矿松软特厚煤层底部9.5m大断面开切眼,支护存在一定难度。分析了顶板岩性及巷道围岩稳定性,根据减跨理论提出了采锚杆、索、梁结合单体的复合支护设计方案,并根据巷道变形监测得出该方案能够有效控制巷道变形。     

Being the CEO's boss: An examination of board chair orientations

Research summary: Scholars have traditionally conceptualized board leadership as a dichotomous construct. A combined CEO and board chair position is interpreted as reflecting a more collaborative approach to corporate governance, whereas separate positions are interpreted as ensuring greater board control. I challenge this conceptualization and posit that a separate board chair can be oriented toward collaboration as well as—or in place of—control. I analyze newly available data from corporate proxy statements to identify these two board chair orientations and test competing perspectives on how they impact profitability growth in a sample of S&P 500 firms. The results indicate that board leadership is a more nuanced phenomenon than the extant literature would suggest . Managerial summary: What is the role of the board chair when not the CEO ? Corporate governance experts assert the board chair's role is to monitor and control the CEO . Yet, board chairs often play another, more collaborative role. Board chairs frequently provide advice and guidance to CEOs and relieve CEOs of board leadership burdens, enabling the CEOs to focus on their primary responsibilities. In this study, I examine the effect of board chair orientations on financial performance and find that, as with separating or joining the CEO and board chair positions, the profitability implications of the selected orientation are far from universal. Board chairs must consider their firm's performance context in order to get the most out of a particular approach to being the CEO 's boss . Copyright © 2016 John Wiley & Sons, Ltd.     

瓦楞纸板配纸设计流程可靠性研究

本论文依据瓦楞纸板配纸设计流程,结合我国新修订的四项国家标准（GB/T 6543—2008、GB/T 6544—2008、GB/T 13023—2008、GB/T 13024—2003）中的相关参数及瓦楞纸板边压强度计算公式,对所研究的瓦楞纸板配纸设计流程可靠性进行验证。实验结果与计算结果吻合良好,表明瓦楞纸板配纸设计流程具有一定的可靠性,可为瓦楞纸板配纸设计提供参考依据。     

Indirect network effects and the quality dimension: A look at the gaming industry

Two-sided markets consist of platforms that need to bring both retail consumers and complementary goods producers on board to be successful. Consumer adoption of these platforms can often hinge on the presence and magnitude of indirect network effects — the positive feedback loop where a larger base of adopters of a primary product (“hardware”) creates a larger market for complementary goods (“software”), which in turn increases the value of the primary good. Prior work attempting to measure indirect network effects often uses aggregate counts of software variety to do so. In this paper, we illustrate the importance of accounting for variation in software quality — a feature present in many markets — when conducting this measurement, and provide the conditions under which not doing so results in over- or underestimation of the actual indirect network effect. We apply our framework to the 7th-generation video game console market with quality-differentiated titles and show that in this market the use of aggregate software measures underestimates the indirect network effects by approximately 30%.     

Do board chairs matter? The influence of board chairs on firm performance

Research summary : We use a variance decomposition methodology to assess the degree to which board chairs may influence their companies' performance. To isolate the board chair effect, we focus on firms in which the CEO and board chair positions are separated. Using a U.S. sample of 6,290 firm‐year observations representing 1,828 board chairs in 308 different industries, our results indicate that the board chair effect is substantial at about nine percent. Drawing on resource dependency theory, we also theorize and show how this board chair effect is contingent on the task environment in which firms operate. Our results add to the literature examining the role and influence of board chairs and the context in which chairs may have a greater impact on performance. Managerial summary : Following institutional and regulatory changes, more firms are separating the CEO and board chair positions. With an increasing number of individuals separate from the CEO serving as board chairs, a critical question becomes: What influence do these separate board chairs have on firm performance? Prior research suggests that separate board chairs can provide important resources—including advice and counsel, legitimacy, information linkages, and preferential access to external commitments and support—to their CEOs, other top managers, and overall firms. In turn, who the board chair is and the individual's ability (or lack thereof) to provide these resources may have a significant impact on firm performance. Offering support for this perspective, we find that separate board chairs explain nine percent of the variance in firm performance. Copyright © 2016 John Wiley & Sons, Ltd.     

Why do some outside successions fare better than others? The role of outside CEOs' prior experience with board diversity

Research summary: We develop a theory to explain why new outside CEOs can better manage their relationship with the board if they previously served on boards that were more diverse than the focal board. We predict that a new outside CEO's prior experience with more diverse boards not only reduces the likelihood of post‐succession CEO turnover and director turnover, but also improves firm performance. Results from an analysis of 188 outside CEOs in a sample of Fortune 500 companies provide support for our theory. This study contributes to upper echelon theory and research by identifying outside CEOs' prior experience with board diversity as an important aspect of their background that influences a range of major organizational outcomes, including CEO turnover, director turnover, and firm performance. Managerial summary: It is challenging to be a new CEO who comes from outside of the organization. Our study examines why some new outside CEOs fare better than others. We suggest that a positive relationship with the board of directors is a key factor in a new outside CEO's success. A new outside CEO can better manage the relationship with the board if he or she has prior experience working with other demographically diverse boards. In contrast, when the focal board is more diverse than the other boards on which the new CEO previously served, the new CEO tends to struggle in managing his or her relationship with the board, experiencing a higher likelihood of turnover and delivering worse financial performance. Copyright © 2015 John Wiley & Sons, Ltd.     

In search of El Dorado: The elusive financial returns on corporate political investments

Although many believe that companies' political activities improve their bottom line, empirical studies have not consistently borne this out. We investigate the relationship between corporate political activity (CPA) and financial returns on a set of 943 S&P 1500 firms between 1998 to 2008. We find that firms' political investments are negatively associated with market performance and cumulative political investments worsen both market and accounting performance. Firms placing former public officials on their boards experienced inferior market performance and similar accounting performance than firms without such board members. We find, however, that CPA is positively associated with market performance for firms in regulated industries. Our results challenge the profit‐maximizing assumptions underlying CPA research and focus on agency theory to better understand CPA. Copyright © 2012 John Wiley & Sons, Ltd.