The coal mine roof rating(CMRR) was developed to bridge the gap between geological variation in underground coal mines and engineering design. The CMRR accounts for the compressive strength of the immediate roof, the ...The coal mine roof rating(CMRR) was developed to bridge the gap between geological variation in underground coal mines and engineering design. The CMRR accounts for the compressive strength of the immediate roof, the shear strength and intensity of any discontinuities present, and the moisture sensitivity of the immediate roof. The CMRR has been widely used and validated in Eastern US coal mines, but it has seen limited application in the Western US. This study focuses on roof behavior at a Western coal mine(Mine A). Mine A shows significant lateral geological variation, along with localized faulting and a laterally extensive sandstone channel network. The CMRR is not used to predict roof instability at the mine. It is, therefore, hypothesized that there are other factors that are correlated with roof instability in underground coal mines that could potentially also be considered in conjunction with the CMRR.This hypothesis was tested by collecting 30 CMRR measurements at Mine A. At each measurement location, a binary record of the roof condition(stable or unstable) was made, and other parameters such as depth of cover, presence of faulting, and sandstone channels were also recorded. ANOVA tests showed that the CMRR values and the roof conditions were not strongly correlated, indicating that the CMRR input criteria are not fully predictive of roof stability at this mine. The CMRR values showed statistically significant correlations(p less than 0.05) with faulting as well as with location at an intersection. For areas that had previously experienced roof fall but were currently stable, faulting was correlated with roof condition(p less than 0.05) only when the condition was classified as unstable.展开更多
我今年55岁,夜里经常失眠。依靠安眠药助眠毕竟不是长久之计。最近我在网上读到一篇短文,是讲改善老人睡眠的。读后很为美国人搞科研的精神和方法所动。他们把参加试验的人分为三组,一组服药,一组服药加行为治疗,一组服用的是安慰剂。...我今年55岁,夜里经常失眠。依靠安眠药助眠毕竟不是长久之计。最近我在网上读到一篇短文,是讲改善老人睡眠的。读后很为美国人搞科研的精神和方法所动。他们把参加试验的人分为三组,一组服药,一组服药加行为治疗,一组服用的是安慰剂。试验结束后再作对比。鄙人孤陋寡闻,尚未见国内搞过如此试验。本文提出了一些很好的改变行为,促进睡眠的建议。我对其中的两条感兴趣,也照办了。一条是Get up at the same time each morning, regardless of the amount of sleep during the previous night.这一条果然灵验。我以前的做法是“堤内损失堤外补”,夜里损失早晨补。这样做的效果其实很差。另一条是把Use the bedroom for sleep and sex only—no reading, TV watching or worrying about sleep,我将电视机从我的卧室“请”了出去,卧室就是卧室,不作他用(值得庆幸的是我最近刚迁人三室一厅的新居)。没有想到,此举真灵!读一篇短文,能学到一两点有用的知识足矣!我将此文用email发给贵刊,并附上我的译文,希望能够刊出,让更多的人能够从中受益。不知译文是否可用。展开更多
这是一则读后让人大吃一惊的消息。美国东海岸一种名叫Pfiesterispiscicida的有毒微生物杀死了数以百万计的鱼。而且,有人也染上了一种可怕的神经综合症: …some sufferers would set out by car on an errand only to forget where the...这是一则读后让人大吃一惊的消息。美国东海岸一种名叫Pfiesterispiscicida的有毒微生物杀死了数以百万计的鱼。而且,有人也染上了一种可怕的神经综合症: …some sufferers would set out by car on an errand only to forget where theywere going and what they had planned to do once they got there. 因此,令人垂涎的所谓生猛海鲜也让人避退三舍: …the seafood industry saw sales plunge by more than $40 million as consumerspanicked over a supposed threat to local fisheries. 再看看我们这里的情形,也让人不寒而栗。据报道,我国渤海已成为一个死海,已无多少鱼虾可捕。 更让人难以置信的是,北极圈一带,由于核潜艇常出没,排放的有害物质污染了海面,侵入幼熊体内,造成它们有雄雌两套生殖器。 Pfiesteria piscicida是新词,我们向上海译文出版社词典编辑室询问此词,也得不到相应的汉译。读者中如有解此“密”者,请写信与我们联系。谢谢！展开更多
据调查,美国近1/4的工人在工作场所长期感到“愤怒”。 其后果是严重的:Angry employees tend to have less energy snd interest inthe job. 怒从何来?下句中的5个由by引导的介词短语道出了全部真情: Employees are most likely to be ...据调查,美国近1/4的工人在工作场所长期感到“愤怒”。 其后果是严重的:Angry employees tend to have less energy snd interest inthe job. 怒从何来?下句中的5个由by引导的介词短语道出了全部真情: Employees are most likely to be angered ba a boss or supervisor(主管),by afellow employee or by others in the workplace not being productive,by tightdeadlines(催逼甚紧的最后期限)or by heavy workloads(工作量). 其中第2、3个介词短语(by a fellow employee or by others in the workplacenot being productive)不可忽视,分词短语折射出了工人的精神状态:anger的原由之一竟是伙伴的not being productive！ 本文对这种现象有一“高屋建瓴”的分析: A turbulent(喧闹的)economic environment that has produced,on the onehand,productivity and growth and. on the other,wrenching(带来痛苦的)change and uncertainty,has buffeted(冲击)the workplace. 问题的两个方面通过上句的 on the one hand和 on the other讲得一清二楚。 这种anger也会演变,演变成本文所说的 workplace aggression,其最高形式是 resort to(诉诸)violence. 本文的末段出现了一个大家已经很熟悉的词汇:rampages(疯狂?展开更多
Since the reform and opening-up to the outside world, China has formed a series of guidelines and policies towards the United States, which are the theoretical foundation of China’s U.S. policy thinking in the New Ce...Since the reform and opening-up to the outside world, China has formed a series of guidelines and policies towards the United States, which are the theoretical foundation of China’s U.S. policy thinking in the New Century. Entering the new century, the international situation has undergone profound and complicated changes, the national strength gap between China and the United States has narrowed, their common interests have expanded, differences and contradictions have increased. Therefore, China stands for both countries to adhere to the direction of developing cooperative partnership, respect each other, abide by the promises, seek equal and mutual benefits and win-win cooperation, and mutually respect each others core interests. The future development of China-U.S. relations still face many challenges and China’s U.S. policy thinking needs to keep abreast with the times.展开更多
贫者日贫,富者日富。这是一个普遍存在于许多国家的现象。自1977年以来,美国老百姓的税后年收入的差距也日益扩大,到了1999年贫富之间的差距达到了创记录的程度。 据统计,美国的高收入者约占其总人口的1％,约270万人。自1977年以来,他...贫者日贫,富者日富。这是一个普遍存在于许多国家的现象。自1977年以来,美国老百姓的税后年收入的差距也日益扩大,到了1999年贫富之间的差距达到了创记录的程度。 据统计,美国的高收入者约占其总人口的1％,约270万人。自1977年以来,他们的收入增加了一倍多,其1999年的预计收入可达51万美元;而占总人口20％的最低收入者,其1999年的预计收入仅为8,800美元。前者是后者的近60倍！ 下面的换算更形象地说明了美国贫富收入之悬殊: …the after-tax income share of the richest 2.7 million people in 1999matched that of the bottom 38 percent of the population,embracing about 100million people. 本文透露的一个重要信息是:美国贫富收入之所以如此悬殊的原因在于: …increased global trade,innovations in technology and weaker laborunions.展开更多
基金supported by a NIOSH Capacity Building grant (No. 200-2016-90154) to Drs. G. Walton and E. Holley and collaborators at the Colorado School of Mines
文摘The coal mine roof rating(CMRR) was developed to bridge the gap between geological variation in underground coal mines and engineering design. The CMRR accounts for the compressive strength of the immediate roof, the shear strength and intensity of any discontinuities present, and the moisture sensitivity of the immediate roof. The CMRR has been widely used and validated in Eastern US coal mines, but it has seen limited application in the Western US. This study focuses on roof behavior at a Western coal mine(Mine A). Mine A shows significant lateral geological variation, along with localized faulting and a laterally extensive sandstone channel network. The CMRR is not used to predict roof instability at the mine. It is, therefore, hypothesized that there are other factors that are correlated with roof instability in underground coal mines that could potentially also be considered in conjunction with the CMRR.This hypothesis was tested by collecting 30 CMRR measurements at Mine A. At each measurement location, a binary record of the roof condition(stable or unstable) was made, and other parameters such as depth of cover, presence of faulting, and sandstone channels were also recorded. ANOVA tests showed that the CMRR values and the roof conditions were not strongly correlated, indicating that the CMRR input criteria are not fully predictive of roof stability at this mine. The CMRR values showed statistically significant correlations(p less than 0.05) with faulting as well as with location at an intersection. For areas that had previously experienced roof fall but were currently stable, faulting was correlated with roof condition(p less than 0.05) only when the condition was classified as unstable.
文摘我今年55岁,夜里经常失眠。依靠安眠药助眠毕竟不是长久之计。最近我在网上读到一篇短文,是讲改善老人睡眠的。读后很为美国人搞科研的精神和方法所动。他们把参加试验的人分为三组,一组服药,一组服药加行为治疗,一组服用的是安慰剂。试验结束后再作对比。鄙人孤陋寡闻,尚未见国内搞过如此试验。本文提出了一些很好的改变行为,促进睡眠的建议。我对其中的两条感兴趣,也照办了。一条是Get up at the same time each morning, regardless of the amount of sleep during the previous night.这一条果然灵验。我以前的做法是“堤内损失堤外补”,夜里损失早晨补。这样做的效果其实很差。另一条是把Use the bedroom for sleep and sex only—no reading, TV watching or worrying about sleep,我将电视机从我的卧室“请”了出去,卧室就是卧室,不作他用(值得庆幸的是我最近刚迁人三室一厅的新居)。没有想到,此举真灵!读一篇短文,能学到一两点有用的知识足矣!我将此文用email发给贵刊,并附上我的译文,希望能够刊出,让更多的人能够从中受益。不知译文是否可用。
文摘这是一则读后让人大吃一惊的消息。美国东海岸一种名叫Pfiesterispiscicida的有毒微生物杀死了数以百万计的鱼。而且,有人也染上了一种可怕的神经综合症: …some sufferers would set out by car on an errand only to forget where theywere going and what they had planned to do once they got there. 因此,令人垂涎的所谓生猛海鲜也让人避退三舍: …the seafood industry saw sales plunge by more than $40 million as consumerspanicked over a supposed threat to local fisheries. 再看看我们这里的情形,也让人不寒而栗。据报道,我国渤海已成为一个死海,已无多少鱼虾可捕。 更让人难以置信的是,北极圈一带,由于核潜艇常出没,排放的有害物质污染了海面,侵入幼熊体内,造成它们有雄雌两套生殖器。 Pfiesteria piscicida是新词,我们向上海译文出版社词典编辑室询问此词,也得不到相应的汉译。读者中如有解此“密”者,请写信与我们联系。谢谢！
文摘据调查,美国近1/4的工人在工作场所长期感到“愤怒”。 其后果是严重的:Angry employees tend to have less energy snd interest inthe job. 怒从何来?下句中的5个由by引导的介词短语道出了全部真情: Employees are most likely to be angered ba a boss or supervisor(主管),by afellow employee or by others in the workplace not being productive,by tightdeadlines(催逼甚紧的最后期限)or by heavy workloads(工作量). 其中第2、3个介词短语(by a fellow employee or by others in the workplacenot being productive)不可忽视,分词短语折射出了工人的精神状态:anger的原由之一竟是伙伴的not being productive！ 本文对这种现象有一“高屋建瓴”的分析: A turbulent(喧闹的)economic environment that has produced,on the onehand,productivity and growth and. on the other,wrenching(带来痛苦的)change and uncertainty,has buffeted(冲击)the workplace. 问题的两个方面通过上句的 on the one hand和 on the other讲得一清二楚。 这种anger也会演变,演变成本文所说的 workplace aggression,其最高形式是 resort to(诉诸)violence. 本文的末段出现了一个大家已经很熟悉的词汇:rampages(疯狂?
文摘Since the reform and opening-up to the outside world, China has formed a series of guidelines and policies towards the United States, which are the theoretical foundation of China’s U.S. policy thinking in the New Century. Entering the new century, the international situation has undergone profound and complicated changes, the national strength gap between China and the United States has narrowed, their common interests have expanded, differences and contradictions have increased. Therefore, China stands for both countries to adhere to the direction of developing cooperative partnership, respect each other, abide by the promises, seek equal and mutual benefits and win-win cooperation, and mutually respect each others core interests. The future development of China-U.S. relations still face many challenges and China’s U.S. policy thinking needs to keep abreast with the times.
文摘贫者日贫,富者日富。这是一个普遍存在于许多国家的现象。自1977年以来,美国老百姓的税后年收入的差距也日益扩大,到了1999年贫富之间的差距达到了创记录的程度。 据统计,美国的高收入者约占其总人口的1％,约270万人。自1977年以来,他们的收入增加了一倍多,其1999年的预计收入可达51万美元;而占总人口20％的最低收入者,其1999年的预计收入仅为8,800美元。前者是后者的近60倍！ 下面的换算更形象地说明了美国贫富收入之悬殊: …the after-tax income share of the richest 2.7 million people in 1999matched that of the bottom 38 percent of the population,embracing about 100million people. 本文透露的一个重要信息是:美国贫富收入之所以如此悬殊的原因在于: …increased global trade,innovations in technology and weaker laborunions.
