The gas outburst, resulting in substantial economic losses and even casualties, is the biggest obstacle in coal mines, mostly caused by an imbalance of gas-geological structure. For accurately measuring this proneness, in this paper, a novel evaluation method was proposed based on the gas-geology theory. In this method, a standardization model of statistical units was presented first, which was used to standardize and quantify the 12 chosen gas-geological factors; and then, an associated function was established for computing the gas-geological complexity index (GCI). With increasing GCI values, the evaluated area was divided into four grades: simple, medium, complex, and extremely complex region, in which the associated proneness of outbursts was SAFE, POTENTIAL, HIGH, STRONG, respectively. Taking the XueHu Coal Mine as an example, site verification was carried out with a good result. Research and application indicate that (1) gas outburst is unbalanced and closely related to the complex of the gas geological structure, showing a greater GCI leads to a higher outburst possibility; (2) the most likely area for the gas outburst is the extremely complex region and the transition zone between adjacent areas with different GCI grades; (3) upgrading-targeted control measures are the best way for preventing and controlling disasters caused by the gas and outburst unbalanced distribution. This novel method provided a reliable quantity approach for predicting and zonally managing gas outbursts and improving the effectiveness of outbursts prevention.
Doklady Earth Sciences - In October 2019, extremely impressive, fresh ruptures of the surface on the mud volcano of Mount Karabetova were discovered. The ruptures are represented by all the main... 相似文献
Water Resources - With the acceleration of industrialization and urbanization, the water crisis is becoming more severe and may threaten the future of sustainable development. Assessing grey water... 相似文献
Adsorption by nanoporous media is critically involved in many fundamental geological and geochemical processes including chemical weathering,element migration and enrichment,environmental pollution,etc.Yet,the adsorption behavior of metal ions on nanoporous materials has not been systematically investigated.In this study,MCM-41 material with a monodisperse pore size(4.4 nm)and a large BET specific surface area(839 m^2/g)was hydrothermally prepared and used as a model silica adsorbent to study the adsorption characteristics of Cu^2+as a representative metal ion.The Cu^2+adsorption capacity was found to increase with increasing suspension pH in the range from 3 to 5 and to decrease in the presence of NaNO3.At 25℃,pH=5,and a solid-to-liquid ratio of 5 g/L,the adsorption capacity was determined to be 0.29 mg/g,which can be converted to a dimensionless partition coefficient of 45,indicating a strong enriching effect of nanoporous silica.The adsorption isotherm and kinetic data were fitted to several commonly used thermodynamic,kinetic,and diffusion models.The adsorption mechanism was also studied by Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy and synchrotron-based X-ray absorption spectroscopy.The results suggest that Cu2+ion adsorption is an entropy-driven endothermal process,possibly involving both outer-sphere and inner-sphere complexes. 相似文献
Quantitative climate reconstruction on long timescales can provide important insights for understanding the climate variability and providing valuable data for simulations. Unfortunately, the credibility of some attempts was hampered by incomplete reconstruction procedures. We here establish a comprehensive framework resting on high-quality Chinese modern pollen database, including modern pollen data screening, calibration set selection, major climate factor analysis, appropriate model selection, strict statistical assessment of results and ecological interpretation. The application of this framework to three high-resolution pollen records from the eastern Tibetan Plateau allows accurate quantitative inferences of Holocene temperature changes, which is the major control of regional vegetation. The results show that the mean warmest month temperature(MTwa)during the early Holocene was ca. 10.4℃ and reached the highest value at 8.5–6 ka BP(ca. 11℃). The early and mid-Holocene(11–5 ka BP) warmth was followed by 1.2℃ temperature decrease, culminating in the coolest temperatures of the Holocene during the Neoglacial cooling. Superimposing on the general cooling trend, MTwareveals a significant 500-yr periodicity with varying intensities through time, showing that warm(cold) intervals are in phase with solar maxima(minima) periods. This spectral similarity indicates a possible connection of multi-century scale climate fluctuations with solar forcing. 相似文献