气动潜孔锤钻进技术在非洲地区供水井施工中的应用

河南地矿行业先后在非洲的多个国家,采用气动潜孔锤钻进技术完成城镇及农村人畜供水钻井工程十余万米,为河南地矿行业后期国外地质找矿、资源开发战略奠定了基础。以肯尼亚共和国那库鲁城市供水施工项目和几内亚共和国52眼井供水项目为例,总结分析气动潜孔锤钻进技术在非洲国家人畜供水井施工中的经验与措施,可为同类取水工程提供借鉴。     

东秦岭216.8Ma前一个7级隐爆大地震的震源遗迹

依据野外地质勘查、工程揭露、地球物理探测等事实和地球化学测量资料,发现位于华北板块南缘东秦岭216.8Ma前一个古地震的震源遗迹。结合隐爆角砾岩体、系列隐爆角砾岩、岩石地球化学、同位素示踪、同位素测年、稀土元素、包裹体、岩石微观破碎等特征分析表明,该震源遗迹是在印支晚期杨子板块与华北板块碰撞对接的造山阶段,上地幔或下地壳形成的源于变质火山岩深熔的I型造山带花岗岩浆,在结晶分异过程中产生大量气液流体并沿断裂通道上升,进入硅化封闭的局部断裂空间后形成岩浆分异气液流体压力,当积聚的巨大压力超过所处深度的静岩压力与聚压空间围岩的破裂强度极限后,在地壳深部产生强烈隐爆所形成。根据上覆地层厚度、可参照的深成侵入岩体相对高度对比和主震遗迹的尺度等分析,隐爆深度位于当时地表的10km以下,隐爆主震的面波震级MS＞7.0。该震源遗迹的发现,可初步确认岩浆气液隐爆成因地震存在,并有助于克服一些地震成因研究中的震源不可视与不可入性难题,为地震成因乃至地震预测探索提供一些可直接观测研究的震源实体。 该遗迹不是一般的地震遗迹,而是一个“震源”实体遗迹——震源遗迹,而且是一个具有震源深度、发生年代、地震强度等地震要素完整且一致的可见震源遗迹。     

Measurement of evaporation from the forest floor in a deciduous forest throughout the year using microlysimeter and closed‐chamber systems

Evaporation from the forest floor (E_FF) in a deciduous broadleaf forest was measured using microlysimeter and closed‐chamber systems. The microlysimeter was used at six points in the experimental basin, and measurements gave different E_FF values at different points. This could be attributed to the local photoenvironment of each sampling point, rather than to litter conditions, if the spatial variation in air temperature (Ta) or vapour pressure deficit (VPD) at the forest floor was small within this basin. A detachable microlysimeter measured condensation in the litter layer during the night, indicating that the litter layer, as well as the mulch layer, played a role in preventing evaporation from the soil layer. The closed‐chamber system made it possible to continuously measure long‐term E_FF. E_FF was closely related to VPD; even during the night, when solar radiation was zero, E_FF amounted to 14·0% of the daily E_FF. The daily E_FF was 0·20 ± 0·13 mm day^?1 during the study period, with two seasonal peaks: in late spring (0·31 mm day^?1 in April) and early fall (0·22 mm day^?1 in September). The former peak has been reported from two deciduous forests in Japan and is strongly related to the solar radiation reaching the forest floor when the trees are dormant. Copyright © 2008 John Wiley & Sons, Ltd.     

Comment on Fofonoff's mode

Abstract

Recently Merkine, Mo and Kalnay (1985) have re-examined the possible existence of Fofonoff's (1954) steady free inertial solution and the role of Fofonoff's mode in numerical circulation models after Veronis (1966). Merkine et al. conclude that the Fofonoff mode does not occur, that such a mode would be barotropically unstable and that resemblances between numerical circulations and Fofonoff's mode are more dependent upon the natures of forcing and dissipation. On the contrary, I suggest that Fofonoff's mode very naturally does emerge and that forcing and dissipation only impede the full realization of Fofonoff's mode. Moreover, statistical mechanical arguments from Salmon, Holloway and Hendershott (1976) show that the Fofonoff mode is expected to co-exist with a transient eddy field whose statistics are in equilibrium with the mode; thus bartotropic instability does not argue for non-realization of Fofonoff's mode.     

川滇块体东缘地壳动力学问题的讨论

从川滇块体东缘的地质构造应力场、地震形变带所反映的构造应力场 ,震源机制解所确定的应力场、地壳应力解除及地壳应力测量所反映的应力场等方面的资料 ,对块体东缘地壳动力学问题进行了讨论 ,结果认为印度板块与欧亚板块的碰撞是川滇块体东缘地壳动力的主要力源。     

General planetary theory in elliptic functions

It is shown that the first-order general planetary theory, i.e. the theory without secular terms, developed in (Brumberg and Chapront, 1973) may be re-constructed and presented by the series in powers of the eccentricity and inclination variables with the closed form coefficients expressed in terms of elliptic functions. The intermediate solution of the zero degree in eccentricities and inclinations has been given explicitly with the aid of elliptic functions and the Hansen type quadratures with trigonometric function kernels. In determining the first and higher degree terms in eccentricities and inclinations one meets the Hansen type quadratures with elliptic function kernels. The secular evolution is described by the autonomous polynomial differential system.     

An accurate solution in magnetic shearing dynamics

In this paper an exact solution of magnetic shearing dynamics in the stage of linear development under constant gas density is obtained. Numerical results in the cases of constant and gravity-stratified densities show that their difference is very small when the gas/magnetic pressure ratio β is of the order of 10⁻². Therefore our results are applicable to the actual solar atmosphere. It is shown that the amplitude of velocities grows almost linearly with tine and falls slowly with height, the fall getting slower all the time. This peculiar behaviour makes the magnetic arch rise higher and higher while the feet of the magnetic loops remain nearly fixed. Thus, a closed magnetic arch system may eventually become open.     

Trends and interventions in large whale entanglement along the South African coast

The major causes of large whale entanglement in South Africa are static fishing gear, especially the type associated with the West Coast rock lobster Jasus lalandii industry, and large-mesh gillnets that are set off the coast of KwaZulu-Natal (KZN) to reduce shark attacks (shark nets). The prevalence of entanglements is seasonal with the peaks in activity coinciding with the breeding migrations of humpback whales Megaptera novaeangliae and southern right whales Eubalaena australis, the two large whale species that are the most prone to entanglement. Generalised linear models with a Poisson or quasi-Poisson distribution were used to describe the relationship between the number of incidents and time. Taking into account the combined length of shark-net installations per year as an offset variable, entanglement of humpback whales in shark nets increased at 15.1% per year (95% CI = 9.5–21.6%) from 1990 to 2009. This is comparable to the rate of increase in the numbers of this species migrating past the KZN coast, between 1988 and 2002 (9–11%). The number of reported incidents of southern right whales entangled in gear other than shark nets also increased between 1990 and 2009. This was accounted for by the increase in numbers of this species in South Africa (7% per year), so in neither case are the two species at increasing risk of individual entanglement, and anthropogenic factors including entanglement do not seem to be affecting the recovery of these whale populations. Nevertheless, there is concern regarding the vulnerability to entanglement of a small assemblage of humpback whales that habitually visits the West Coast in spring and summer. The continued recovery of whale populations is likely to lead to greater levels of anthropogenic interaction and heighten the need for adequate mitigation measures. The KZN Sharks Board and the South African Whale Disentanglement Network (since 2006) have respectively released (disentangled) 81% and 23% of confirmed entangled individuals, and recorded relevant information on entanglement incidents. Such information is critical for developing mitigation measures and monitoring the prevalence of entanglement.     

一种高效的最小独立闭合环自动搜索算法

依据图论理论,在基于生成树、余树变换的闭合环搜索算法和基于深度优先的闭合环搜索算法的基础上,提出一种高效且稳定性好的控制网最小独立闭合环自动搜索算法.     

Power and robustness of Aitchison's test for complete subcompositional independence in closed arrays

This paper examines some aspects of the power and robustness of the test for complete subcompositional independence proposed by Aitchison (1982). Although the computed test statistics commonly do not approach being ² distributed throughout their range, the upper tail of their distribution does mimic the ² distribution sufficiently to yield a quite robust test when variates are drawn from identical distributions with different distribution parameters or even when variates are drawn from different distributions. But the magnitude of correlations among the variables and the proportion of correlated to independent variables that compose the closed data vectors affect the power of the test.