本刊本期拟集中“谈论”了El Nine现象。尽可能让我们的读者对ElNine现象有一个全面的认识。本文的录用就出于此考虑。 无疑,在我们的头脑里,此现象似乎有百弊而无一利。Get Ready for SomeWild Weather一文虽然提出了Is there a good s...本刊本期拟集中“谈论”了El Nine现象。尽可能让我们的读者对ElNine现象有一个全面的认识。本文的录用就出于此考虑。 无疑,在我们的头脑里,此现象似乎有百弊而无一利。Get Ready for SomeWild Weather一文虽然提出了Is there a good side to El Nino?的问题,但是,其回答失之简单,而本文则能弥此不足,把问题的另一面谈得比较深入。 在一片对El Nine现象的责难声中,文章观点鲜明,亮出了此现象“造福于人类”的事实: El Nine—the periodic warming of eastern Pacific Ocean waters—causes a burstof plant growth throughout the world,and this removes carbon dioxide from theatmosphere! 须知,数十年来,人类为大气中二氧化碳的增加伤透了脑筋。并将其原因归结于:a.an expanded use of fosil fuels;b.toppling of tropical forests;C.greenhouseeffect。除此之外,人们曾一度“冤枉”了El Nine现象: satellite measurements of CO_2,plant growth and temperature show that naturalwarming events such as El Nine at first cause more CO_2 to be released into theatmosphere,probably as the result of accelerated decay of dead plant matter in the soil. 有趣的,令人欣喜的发现终于还El展开更多
目的探讨 Goode T 型鼓膜通气管的短期疗效。方法 33例(39耳)分泌性中耳炎(secretory otitismedia,SOM)患者置入 Goode T 型鼓膜通气管,同期采用国产纽扣状鼓膜通气管治疗患者30例(40耳)作为对照,随访6个月,比较两种通气管的疗效及并发...目的探讨 Goode T 型鼓膜通气管的短期疗效。方法 33例(39耳)分泌性中耳炎(secretory otitismedia,SOM)患者置入 Goode T 型鼓膜通气管,同期采用国产纽扣状鼓膜通气管治疗患者30例(40耳)作为对照,随访6个月,比较两种通气管的疗效及并发症。结果术后6个月,Coode T 型鼓膜通气管组的堵管、排出和重新置管率均明显低于国产通气管组,P<0.001,差异极显著;术后除2例耳漏外,未发现其他严重并发症。两组患者术后近期听力学检查结果差异无显著性。结论 Goode T 型鼓膜通气管可适用于无置管史的 SOM 患者的短期治疗。展开更多
Large goods transported in railway are kinds of special goods and they are very important in national construction. In order to transport safely, loading and reinforcing schemes must be made first. How to design a rea...Large goods transported in railway are kinds of special goods and they are very important in national construction. In order to transport safely, loading and reinforcing schemes must be made first. How to design a reasonable scheme will be affected by many factors. This paper presents the characteristic of the large goods, summarizes the process of designing a loading and reinforcing scheme of large good, then probes the factors of affecting the loading and reinforcing scheme and gives a detail analysis. It’s considered that those out-of-gauge and overweight degree of goods, center-of- gravity height of a loaded wagon, position of center-of-gravity of goods, type of wagon for using, reinforcement material and reinforcement method, transport expense and transport organization could affect a scheme in the aspects of safety, economy, rapidity and convenience. This conclusion will instruct and help to make a good scheme.展开更多
We investigate the evolution of cooperation in public goods game based on individuals' historical payoffs. In particular, the fitness of individuals are characterized by two types of payoffs, which are obtained by...We investigate the evolution of cooperation in public goods game based on individuals' historical payoffs. In particular, the fitness of individuals are characterized by two types of payoffs, which are obtained by acting as cooperators and defectors, respectively. Both of payoffs are the linear combination of the current payoffs and the cumulative historical payoffs. The results show that cooperation is enhanced by an increasing memory effect with a wide range of related factors. To explain this phenomenon, we plot some representative snapshots of the population and scrutinize the mean fitness of cooperators and defectors along the boundary. It is found that increasing memory effect induces a positive feedback mechanism for cooperators to expand their districts. Defectors can just survive through forming narrower clusters to exploit cooperators more widely. The threshold values for cooperators and defectors vanishing under the influence of noise are also investigated.展开更多
文摘本刊本期拟集中“谈论”了El Nine现象。尽可能让我们的读者对ElNine现象有一个全面的认识。本文的录用就出于此考虑。 无疑,在我们的头脑里,此现象似乎有百弊而无一利。Get Ready for SomeWild Weather一文虽然提出了Is there a good side to El Nino?的问题,但是,其回答失之简单,而本文则能弥此不足,把问题的另一面谈得比较深入。 在一片对El Nine现象的责难声中,文章观点鲜明,亮出了此现象“造福于人类”的事实: El Nine—the periodic warming of eastern Pacific Ocean waters—causes a burstof plant growth throughout the world,and this removes carbon dioxide from theatmosphere! 须知,数十年来,人类为大气中二氧化碳的增加伤透了脑筋。并将其原因归结于:a.an expanded use of fosil fuels;b.toppling of tropical forests;C.greenhouseeffect。除此之外,人们曾一度“冤枉”了El Nine现象: satellite measurements of CO_2,plant growth and temperature show that naturalwarming events such as El Nine at first cause more CO_2 to be released into theatmosphere,probably as the result of accelerated decay of dead plant matter in the soil. 有趣的,令人欣喜的发现终于还El
文摘目的探讨 Goode T 型鼓膜通气管的短期疗效。方法 33例(39耳)分泌性中耳炎(secretory otitismedia,SOM)患者置入 Goode T 型鼓膜通气管,同期采用国产纽扣状鼓膜通气管治疗患者30例(40耳)作为对照,随访6个月,比较两种通气管的疗效及并发症。结果术后6个月,Coode T 型鼓膜通气管组的堵管、排出和重新置管率均明显低于国产通气管组,P<0.001,差异极显著;术后除2例耳漏外,未发现其他严重并发症。两组患者术后近期听力学检查结果差异无显著性。结论 Goode T 型鼓膜通气管可适用于无置管史的 SOM 患者的短期治疗。
文摘Large goods transported in railway are kinds of special goods and they are very important in national construction. In order to transport safely, loading and reinforcing schemes must be made first. How to design a reasonable scheme will be affected by many factors. This paper presents the characteristic of the large goods, summarizes the process of designing a loading and reinforcing scheme of large good, then probes the factors of affecting the loading and reinforcing scheme and gives a detail analysis. It’s considered that those out-of-gauge and overweight degree of goods, center-of- gravity height of a loaded wagon, position of center-of-gravity of goods, type of wagon for using, reinforcement material and reinforcement method, transport expense and transport organization could affect a scheme in the aspects of safety, economy, rapidity and convenience. This conclusion will instruct and help to make a good scheme.
基金Supported by the National Natural Science Foundation of China (NSFC) (No. 61074120)
文摘We investigate the evolution of cooperation in public goods game based on individuals' historical payoffs. In particular, the fitness of individuals are characterized by two types of payoffs, which are obtained by acting as cooperators and defectors, respectively. Both of payoffs are the linear combination of the current payoffs and the cumulative historical payoffs. The results show that cooperation is enhanced by an increasing memory effect with a wide range of related factors. To explain this phenomenon, we plot some representative snapshots of the population and scrutinize the mean fitness of cooperators and defectors along the boundary. It is found that increasing memory effect induces a positive feedback mechanism for cooperators to expand their districts. Defectors can just survive through forming narrower clusters to exploit cooperators more widely. The threshold values for cooperators and defectors vanishing under the influence of noise are also investigated.
