Unraveling methanogenesis processes and pathways for Quaternary shallow biogenic gas in aquifer systems through geochemical, genomic and transcriptomic analyses.

Shallow biogenic gas is crucial in global warming and carbon cycling. Considering the knowledge gap in the understanding of methanogenesis and metabolic mechanisms within shallow groundwater systems, we investigated Quaternary shallow biogenic gas resources from the Hetao Basin in North China, which were previously underexplored. We systematically analyzed the genesis of gas and formation water, microbial communities, methanogenic processes, and pathways using geochemistry, genomics, and transcriptomics.

Mineral Characteristics of Low-Rank Coal and the Effects on the Micro- and Nanoscale Pore-Fractures: A Case Study from the Zhundong Coalfield, Northwest China.

The mineral characteristics (occurrence, type, and content) of low-rank coal and their influence on coalbed methane (CBM) reservoirs are investigated at the micro- and nanoscales. Six coal samples of three representative coalmines were used to demonstrate the uniform tectonization from the Zhundong coalfield, NW China. Based on optical microscopy and scanning electron microscopyenergy dispersive spectrum (SEM-EDS) analysis, the mineral composition and occurrence characteristics were discussed.

A Refinement of Nitrogen Isotope Analysis of Coal Using Elemental Analyzer/Isotope Ratio Mass Spectrometry and the Carbon and Nitrogen Isotope Compositions of Coals Imported in China.

The ability to accurately analyze nitrogen (N) isotopes of coal is important for evaluating its contribution to NO emissions to the atmosphere via coal combustion. Although an elemental analyzer/isotope ratio mass spectrometer is highly efficient for analyzing the N isotopes of coal, it requires large amounts of organic matter (>3 mg) to produce enough N to enable N isotope measurements due to the high organic carbon contents of coal with relatively low N contents. Therefore, to completely oxidize the organic matter, more oxidant matter is required to enhance coal combustion in a reactor tube in an elemental analyzer through injecting O during the combustion process.

Formation of large carbonate concretions in black cherts in the Gufeng Formation (Guadalupian) at Enshi, South China.

The formation of carbonate concretions is a cementation process which passively infills the pore spaces within sediments. They record the original environments of deposition and diagenetic conditions of the host rocks. Little is known about the precise mechanisms responsible for the precipitation of carbonate concretions.

Hydrogeochemistry signatures of produced waters associated with coalbed methane production in the Southern Junggar Basin, NW China.

The Southern Junggar Basin (SJB) in China is an emerging coalbed methane (CBM) development area with abundant low-rank CBM resources. CBM development is accomplished by pumping significant volumes of water from the aquifer, and this water is commonly termed as produced water, which has great utilization values for the water-deficient areas like SJB. Geochemistry signatures are prerequisites in the management of the produced water.

Changes in Concentration and Distribution of Biomarkers in Biodegraded Oils from Dongying Depression, China.

The alkane fraction of 11 biodegraded oils and five non-biodegraded oils from the Dongying Depression, Bohai Bay Basin, eastern China, were analyzed by gas chromatography-mass spectrometry to investigate the biomarker alteration caused by biodegradation. Results indicated that the concentration of 25-norhopanes was correlated with increased biodegradation. The oil samples showed an increase in the C31 and C32 hopane 22S/(22S + 22R), C29 sterane C2920S/(20S + 20R), and C29ββ/(ββ + αα) thermal maturity parameters in the heavily biodegraded oils.

[Design of an artificial sphincter system with bio-feedback function based on MSP430].

In this paper, we advance a new treating method for rectectomy postoperative anus incontinence, which is called "artificial sphincter system with biofeedback-function". The system simulates the function of human's sphincter and has entered into a stage of simulation experiments on animals.