南极罗斯海地质与油气资源潜力     

Coop.  AK 程能友 《海洋地质》1994,(3):58-81

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西罗斯海新生代和（？）中生代地层的构造和沉积控制     

Coop.  AK 欧阳共鸣 《海洋地质》1994,(3):52-58

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用直流电测深和甚低频法确定地下水的污染状况     

Bens.  AK 《地质科学译丛》1997,14(3):54-56,64

地球物理方法可以有效地用来检测土壤和地下水的污染情况。近来在美国犹他州犹他县采用了电阻率测深法和甚低频法来检测浅层没气污染。以胶所打的监测井为分析地下水的化学组分性质提供了极大的方便同时也为地球物理数据的解释提供了辅助信息。  相似文献   

断裂带洼陷中含煤建造形成的主要阶段     

C.  AK 知叶 《国外煤田地质》1995,(3):8-12

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根据GPS测高获取高程     

Chon.  AK 吴志忠 《测绘技术》1993,(3):27-29

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地质雷达在评估某些地质灾害中的应用：地下水污染,断层以及空洞的实例   总被引：1，自引：0，他引：1  

Bens.  AK 吕珍 《地震科技情报》1996,(8):16-26

在适当的地质背景中可以使用地质雷达（ＧＰＲ）来测绘地下地质构造和地下水污染，相关的工程应用和环境应用也很多，尤其是ＧＰＲ可有助于识别污染柱体的大致边界，并现场提供地层信息，亚利桑纳州和犹州他州现场的研究实例说明，在关键井位中ＧＰＲ特征和烃类物污染之间存在着良好的相关性，ＧＰＲ资料在识别浅层断裂时可能很有用的，也可用相关的地下形变的特征更好地了解表破裂的潜在性，从犹他县Ｗａｓｔｃｈ断裂带得到的例子表  相似文献   

High Magnetic Field Pulsars and Magnetars: A Unified Picture     

Zhang B  Harding AK 《The Astrophysical journal》2000,535(1):L51-L54

We propose a unified picture of high magnetic field radio pulsars and magnetars by arguing that they are all rotating high-field neutron stars but that their magnetic axes have different orientations with respect to their rotation axes. In strong magnetic fields where photon splitting suppresses pair creation near the surface, the high-field pulsars can have active inner accelerators while the anomalous X-ray pulsars cannot. This can account for the very different observed emission characteristics of the anomalous X-ray pulsar 1E 2259+586 and the high-field radio pulsar PSR J1814-1744. A predicted consequence of this picture is that radio pulsars having surface magnetic fields greater than about 2x1014 G should not exist.  相似文献   

Anoxia over the western continental shelf of India: bacterial indications of intrinsic nitrification feeding denitrification     

Krishnan KP  Fernandes SO  Loka Bharathi PA  Krishna Kumari L  Nair S  Pratihary AK  Rao BR 《Marine environmental research》2008,65(5):445-455

Studies on the Arabian Sea coastal anoxia have been of immense interest, but despite its ecological significance there is sparse understanding of the microbes involved. Hence, observations were carried out off Goa (15 degrees 30'N, 72 degrees 40'E to 15 degrees 30'N, 72 degrees 59'E) to understand the processes that mediate the changes in various inorganic nitrogen species in the water column during anoxia. Water column chemistry showed a clear distinct oxic environment in the month of April and anoxic condition in October. Our study based on microbial signatures indicated that oxygen deficit appeared as a well-defined nucleus almost 40 km away from the coast during the oxic period (April) and spreads there after to the entire water column synchronizing with the water chemistry. Striking results of net changes in inorganic nitrogen species in nitrification blocked and unblocked experimental systems show that denitrification is the predominant process in the water column consuming available nitrate ( approximately 0.5 microM) to near zero levels within approximately 72 h of incubation. These observations have been supported by concomitant increase in nitrite concentration ( approximately 4 microM). Similar studies on denitrification-blocked incubations, demonstrate the potential of nitrification to feed denitrification. Nitrification could contribute almost 4.5 microM to the total nitrate pool. It was found that the relation between ammonium and total dissolved inorganic nitrogen (DIN) pool (r=0.98, p<0.001, n=122) was significant compared to the latter with nitrite and nitrate. The occurrence of high ammonium under low phosphate conditions corroborates our observations that ammonium does not appear to be locked under low oxygen regimes. It is suggested that ammonium actively produced by detrital breakdown (ammonification) is efficiently consumed through nitrification process. The three processes in concert viz. ammonification, nitrification and denitrification appear to operate in more temporal and spatial proximity than hitherto appreciated in these systems and this gives additional cues on the absence of measurable nitrate at surface waters, which was earlier attributed only to efficient algal uptake. Hence we hypothesize that the alarming nitrous oxide input into the atmosphere could be due to high productivity driven tighter nitrification-denitrification coupling, rather than denitrification driven by extraneous nitrate.  相似文献   

利用基于地理信息系统的专家系统绘制森林土壤图     

斯基.  AK 宛铭 《地理译报》1993,12(4):48-55

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A neural network based methodology to predict site-specific spectral acceleration values     

Kamatchi P  Rajasankar J  Ramana GV  Nagpal AK 《地震工程与工程振动(英文版)》2010,9(4):459-472

A general neural network based methodology that has the potential to replace the computationally-intensive site-specific seismic analysis of structures is proposed in this paper. The basic framework of the methodology consists of a feed forward back propagation neural network algorithm with one hidden layer to represent the seismic potential of a region and soil amplification effects. The methodology is implemented and verified with parameters corresponding to Delhi city in India. For this purpose, strong g...  相似文献