CFM56-5B发动机反推失效故障分析

本文通过CFM56-5B发动机反推失效排故全过程的故障分析,提出了对CFM56-5B发动机在反推排故过程中和维护中的预防措施和建议。希望减少类似故障引起的多次部件拆换,减少排故时间。     

Further empirical evidence on block transactions below the MBR: the Spanish market

There is a relatively unknown market for partial control or corporate influence in Spanish listed firms, where the control transaction size is below the legal threshold that triggers a mandatory tender offer, as this kind of deal looks for exercising some degree of control, but not a full control. The goal of this paper is to go further in its empirical analysis by exploring its distinguishing features, using as the criterion to define its transactions obtaining a seat in the board of directors. We find that these deals are mainly located in the segment of the market of large trades where the rules for private negotiations are easier to implement; the size of the block is relatively large and it is negotiated as a whole block. Besides, the most common buyer has no previous stake in the firm. We find no evidence that the buyers pay, in median, for a seat on the board of directors, but the variability of the premiums for those blocks is higher and shows that buyers that had no control position in the target firm pay more for being among largest shareholders (partial control) and less for not being among them (influence).     

行业板块股价对重大污染事件的应急反应分析

金融市场有效性争议至今没有定论,中国股票市场有效性判断仍有争议。本文从突发性重大污染事件冲击角度,通过行业板块受突发事件冲击后股票价格在H股与A股两个市场应急反应的对比分析,考察我国股票市场的有效性状况,发现H股表现出的反应不足甚于A股,表明我国股票市场已存在短期动量效应,能在一定程度上对当前公开信息作出反应;但这种反应是不足和滞后的,还未达到半强式有效。可见,我国股票市场处于发育初期,公司治理结构政府主导和环境管制不力等综合因素导致了行业板块股价的特殊走势。     

水平井技术在江苏复杂小断块油田的应用

江苏油田地处经济发达的长江＂金三角＂地区,该地区地面水网密布、村庄密集,钻井征地费用高、环保要求高;地下断层发育、油藏规模小,属我国东部复杂小断块油田,开发难度大。近年来,由于水平井技术的广泛应用,推动了江苏油田的发展,文章阐述了江苏复杂小断块油田的基本地质特点,系统介绍了水平井技术在江苏油田试验、研究和应用状况,分析了典型油藏应用效果,提出了对水平井应用的认识和建议。     

决定现金持有量：技术还是制度

本文以2003—2008年上海证劵交易所501家上市公司的数据为样本,从技术（企业成长性）和制度（公司治理机制）两个角度出发,实证研究其对企业现金持有量的影响。实证结果表明：企业成长性与现金持有量正相关;股权集中度与现金持有量负相关;股权制衡度与现金持有量正相关。     

试论加气混凝土砌块墙体裂缝的产生原因

在用户对建筑质量进行评判的时候,建筑裂缝是他们对建筑进行评判的主要目测标准之一。粉煤灰加气混凝土砌块是一种轻质墙体材料,具有良好的隔热性能,施工较为简便而且价格低廉,但是施工不当会导致加气混凝土砌块墙体裂缝的产生。本文主要探讨了加气混凝土砌块墙体裂缝的产生原因,并提出了对策。     

冀中凹陷留107断块堵漏和防漏相结合固井技术

通过优选低密度堵漏型水泥浆体系、优化技术措施、完善工艺流程,研究了堵漏和防漏相结合固井技术,在现场应用中取得了良好效果,固井合格率100%,解决了该区块固井难题,为后续勘探开发积累了有益的经验。     

Cost-effectiveness analysis of roflumilast/tiotropium therapy versus tiotropium monotherapy for treating severe-to-very severe COPD

Abstract

Objective:

To conduct a cost-effectiveness analysis comparing roflumilast/tiotropium therapy vs tiotropium monotherapy in patients with severe-to-very severe COPD.

Methods:

The economic evaluation applied a disease-based Markov cohort model with five health states: (1) severe COPD, (2) severe COPD with a history of severe exacerbation, (3) very severe COPD, (4) very severe COPD with a history of severe exacerbation, and (5) death. Within a given health state, a patient may have a mild/moderate or severe exacerbation or die. Data from roflumilast clinical trials and published literature were used to populate model parameters. The model calculated health outcomes and costs for roflumilast/tiotropium therapy vs tiotropium monotherapy over a 5-year horizon. Incremental cost and benefits were then calculated as cost-effectiveness ratios, including cost per exacerbation avoided and cost per quality adjusted life year ($/QALY).

Results:

Over a 5-year horizon, the estimated incremental costs per exacerbation and per severe exacerbation avoided were $589 and $5869, respectively, and the incremental cost per QALY was $15,815. One-way sensitivity analyses varying key parameters produced an incremental cost per QALY ranging from $1963–$32,773.

Limitations:

A number of key parameters used in the model were obtained from studies in the literature that were conducted under different contexts. Specifically, the relative risk estimate for severe COPD patients originates from a small trial not designed to demonstrate the impact of roflumilast on frequency of exacerbations. In addition, the model extrapolates the relative risk estimates over periods of 5–30 years, even though the estimates were only observed in trials that spanned less than a year.

Conclusions:

The addition of roflumilast to tiotropium is cost-effective for the treatment of severe to very severe COPD patients.     

基于Turbo-TCM与时空分组码的级联系统的次优译码算法

针对瑞利信道中存在的严重的多径衰落，本文实现了Turbo-TCM方案与时空分组码的级联系统，以期利用空间分集改善系统的误码率性能。针对级联系统的译码，本文给出了一种具有低译码时延的次优译码算法，该算法的特点是各模块独立译码，先算比特对数似然比再进行二进制Turbo码译码。最后通过计算机仿真给出了使用该次优译码算法的Turbo－TCM方案与时空分组码的级联系统的译码性能。仿真结果说明，当发射天线数目一定时，随着接收天线数目的增加，译码性能的增益随之增加而帧长对译码性能的影响则随之减小。     

大河矿区下草坪矿段构造特征及其对煤层稳定性的影响

文章主要对矿区内的含煤地层特征、构造特征、构造对煤层影响等进行了认真地分析研究,认为本区的总体构造形态为向斜与背斜构成的复合构造,断层对煤层稳定性影响表现为中等,对煤层开采影响较大。这一研究为今后周边矿区地质勘探及煤炭开发提供了理论依据。