Hydrocarbon reservoirs in a trachyte porphyry intrusion in the Eastern depression of the Liaohe basin, northeast China

Author(s):  
Lianxing Gu,1 Zuowei Ren,2 Changzhi
AAPG Bulletin ◽  
2005 ◽  
Vol 89 (12) ◽  
pp. 1629-1649 ◽  
Author(s):  
Liguo Hu ◽  
Andreas Fuhrmann ◽  
Harald S. Poelchau ◽  
Brian Horsfield ◽  
Zhanwen Zhang ◽  
...  

Geophysics ◽  
2001 ◽  
Vol 66 (3) ◽  
pp. 809-813 ◽  
Author(s):  
Jianzhong Zhang ◽  
Benshan Zhong ◽  
Xixiang Zhou ◽  
Yun Dai

A new method is presented to compute gravity anomalies that result from 2-D bodies with variable density contrast. The cross‐section of a body is approximated by a polygon. Density is assumed to vary as any order of polynomial function with depth and lateral position. Results calculated by the proposed method for models with variable density contrast compare well with other methods. Liaohe basin, northeast China, is modeled from field gravity anomalies using the formulas given, showing the method is valid and effective.


2020 ◽  
Vol 85 ◽  
pp. 183-196
Author(s):  
Y Sun ◽  
J Liu ◽  
Q Yao ◽  
J Jin ◽  
X Liu ◽  
...  

Viruses are the most abundant and ubiquitous biological entities in various ecosystems, yet few investigations of viral communities in wetlands have been performed. To address this data gap, water samples from 6 wetlands were randomly collected across northeast China; viruses in the water were concentrated by sequential tangential flow filtration, and viral communities were assessed through randomly amplified polymorphic DNA-PCR (RAPD-PCR) with 4 decamer oligonucleotide primers. Principal coordinate analysis and hierarchical clustering analysis of the DNA fingerprints showed that viral community compositions differed among the water samples: communities in the 2 coastal wetlands were more similar to each other than to those in the 4 freshwater wetlands. The Shannon-Weaver index (H) and evenness index (E) of the RAPD-PCR fingerprint also differed among the 6 wetlands. Mantel test revealed that the changes in viral communities in wetland water were most closely related to the water NH4+-N and inorganic C content, followed by total K, P, C and NO3--N. DNA sequence analysis of the excised bands revealed that viruses accounted for ~40% of all sequences. Among the hit viral homologs, the majority belonged to the Microviridae. Moreover, variance partitioning analysis showed that the viral community contributed 24.58% while environmental factors explained 30.56% of the bacterial community variation, indicating that the bacterial community composition was strongly affected by both viral community and water variables. This work provides an initial outline of the viral communities from different types of wetlands in northeast China and improves our understanding of the viral diversity in these ecosystems.


2016 ◽  
Vol 67 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Y Liu ◽  
L Wang ◽  
B Liu ◽  
M Henderson

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