The relationship between plant community and soil factors in spoil bank of coal mine under different reclamation modes

2014 ◽  
pp. 163-169
Author(s):  
T Wang ◽  
X Huang ◽  
Y Bao ◽  
X Gan
Keyword(s):  
Plant Community ◽  
Coal Mine ◽  
Soil Factors ◽  
Spoil Bank ◽  
The Relationship

scholarly journals Mechanical Model of the Initial Leg Pressure Increment of the Shield and Its Application to Monitor Roof Load in Longwall Panels

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Like Wei
Keyword(s):  
Coal Mine ◽  
Pressure Difference ◽  
Mechanical Model ◽  
Main Roof ◽  
Mine Pressure ◽  
Initial Stage ◽  
Proposed Model ◽  
Pressure Increment ◽  
The Relationship ◽  
Leg Pressure

The shield pressure cannot always be used to represent the upper load of longwall panels, since its value is steady or even decreases by the yielding action. However, the leg pressure increment of the shield (LPIS) at the initial stage is not influenced by yielding and could therefore be an important factor to judge the state of overlying loads. In this study, a mechanical model is established to analyze the relationship between the overlying loads of the main roof and LPIS after cutting. There is a linear positive correlation between leg pressure increment and overlying loads and a second-order relationship between leg pressure increment and length of main roof cantilever in the proposed model. Therefore, it can be used to determine the magnitude of roof weighting strength in different periods as well as the length of the main roof cantilever in a period. Finally, the mine pressure difference between the period of fully mechanized mining and the period of fully mechanized caving mining in the MinDong-1 coal mine serves to verify the rationality of the proposed model.

Occurrence and distribution of vermiform plant-parasitic nematodes and the relationship with soil factors in field pea (Pisum sativum) in North Dakota, USA

Nematology ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 445-457 ◽  
Author(s):  
Arjun Upadhaya ◽  
Guiping Yan ◽  
Julie Pasche ◽  
Audrey Kalil
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Field Pea ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Soil Factors ◽  
The Usa ◽  
Nematode Abundance ◽  
The Relationship ◽  
Plant Parasitic

Summary Plant-parasitic nematodes restrict crop growth and cause yield loss in field pea (dry edible pea). A 4-year survey of commercial pea fields was conducted in North Dakota, one of the leading producers of field pea in the USA, to investigate nematode distribution, prevalence, abundance and association with soil properties. Beginning in 2014, a total of 243 soil samples were collected from 16 counties, and soil properties of 115 samples were analysed to determine the association of nematodes with soil factors (texture, organic matter, nutrients). The plant-parasitic nematode genera, Paratylenchus (absolute frequency = 58-100%; mean density = 470-1550 (200 g soil)−1; greatest density = 7114 (200 g soil)−1) and Tylenchorhynchus (30-80%; 61-261; 1980, respectively), were the most frequent and widely distributed. Pratylenchus and Helicotylenchus were identified in one-third of the counties surveyed with mean densities ranging from 43 to 224 and 36 to 206 (200 g soil)−1, respectively. Xiphinema was found relatively frequently but at low densities. Hoplolaimus and Paratrichodorus were rarely detected at lower densities. Canonical correspondence analysis revealed that soil factors explained 19% of the total variance of nematode genera abundance. The relationship between nematode abundance and soil sand content and pH was significant, while clay, silt, organic matter and nutrients were not significantly related to nematode abundance. This is the first multi-year study investigating nematodes associated with field peas and their relationship with soil factors in a major field pea production region of the USA.

Study on the Relationship of the Quantity of CO2 Produced and the Wind Speed

2014 ◽  
Vol 881-883 ◽  
pp. 1638-1641
Author(s):  
Xian Long Sun ◽  
Er Xin Gao ◽  
Hong Fen Zhang ◽  
Qiang Wang ◽  
Li Juan Li
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Coal Seam ◽  
Coal Mine ◽  
Laboratory Experiments ◽  
Spontaneous Combustion ◽  
Geothermal Heat ◽  
Research Results ◽  
Relationship Of ◽  
The Relationship

Based on the geological and the experimental data of the13#coal seam of Sun-Cun Coal Mine, the relationship curve between the geothermal heat in Sun-Cun coal mine and experimental wind speed has been fit out.According this and the laboratory experiments,the relational expression between the quantity of CO2 produced in the period of spontaneous combustion and the wind speed in the coal mine has been developed. The research results show that when the wind speed exceeds 2m/s,the quantity of CO2 produced has a sharp rising tendency.

Fine-textured soil bands and oak forest productivity in northwestern lower Michigan, U.S.A.

1994 ◽  
Vol 24 (5) ◽  
pp. 928-933 ◽  
Author(s):  
Joseph P. McFadden ◽  
Neil W. MacDonald ◽  
John A. Witter ◽  
Donald R. Zak
Keyword(s):  
Soil Texture ◽  
Positive Relationship ◽  
Linear Regression Analysis ◽  
Forest Productivity ◽  
Field Method ◽  
Textural Analysis ◽  
Oak Forest ◽  
Soil Factors ◽  
Highly Correlated ◽  
The Relationship

The relationship between fine-textured soil bands and forest productivity was studied by comparing three mixed-oak (Quercusrubra L. and Quercusalba L.) stands that had little or no fine-textured banding with three stands that had bands. The degree to which soil factors could account for differences in productivity between banded and unbanded stands was examined using two methods, one based on field observations (banding codes) and the other based on laboratory textural analysis. Because stand ages were not significantly different, overstory biomass was used as an index of productivity. Mean overstory biomass in the banded stands was 312 Mg/ha, significantly greater than 170 Mg/ha measured in the unbanded stands. Mean percent clay + silt and mean banding code also were significantly higher in banded than in unbanded stands. Linear regression analysis indicated that mean percent clay + silt accounted for 57% of the variation in overstory biomass, whereas mean banding code accounted for 40% of the variation. In the oak stands we studied, variation in productivity can be explained largely by differences in soil texture associated with fine-textured bands. We also found a positive relationship between mean banding code and mean percent clay + silt (r2 = 0.90), which suggests that the field method of quantifying banding can produce values that are highly correlated with soil texture and, by extension, forest productivity.

scholarly journals Determination of cyclic filling length in gob-side entry retained with roadside filling and its application

2020 ◽  
Author(s):  
Zizheng Zhang ◽  
Jianbiao Bai ◽  
Xianyang Yu ◽  
Weijian Yu ◽  
Min Deng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Difference Method ◽  
Suggested Method ◽  
Stress Difference ◽  
Thick Coal Seam ◽  
Mechanics Model ◽  
Working Face ◽  
Geological Conditions ◽  
The Relationship

Abstract Gob-side entry retained with roadside filling (GER-RF) plays a key role in achieving coal mining without pillar and improving the coal resource recovery rate. Since there are few reports on the cyclic filling length of GER-RF, a method based on the stress difference method is proposed to determine the cyclic filling length of GER-RF. Firstly, a stability analysis mechanics model of the immediate roof above roadside filling area in GER was established, then the relationship between the roof stress distribution and the unsupported roof length was obtained by the stress difference method. According to the roof stability above roadside filling area based on the relationship between the roof stress and its tensile strength, the maximum unsupported roof length and rational cyclic filling length of GER-RF. Combined with the geological conditions of the 1103 thin coal seam working face of Heilong Coal Mine and the geological conditions of the 1301 thick coal seam working face of Licun Coal Mine, this suggested method was applied to determine that the rational cyclic filling lengths of GER-RF were 2.4 m and 3.2 m, respectively. Field trial tests show that the suggested method can effectively control the surrounding rock deformation along with rational road-in support and roadside support, and improve the filling and construction speed.

Surface Runoff and Its Erosion Energy in a Partially Continuous System: An Ecological Hydraulic Model

2009 ◽  
Author(s):  
Huayong Zhang ◽  
Liming Dai
Keyword(s):  
Energy Dissipation ◽  
Plant Community ◽  
Surface Runoff ◽  
Ground Surface ◽  
Continuous System ◽  
Hydraulic Model ◽  
Dynamical Process ◽  
Erosion Process ◽  
The Relationship ◽  
Stable Development

Plant community and ground surface form a partially continuous ecosystem in conveying surface runoff and its erosion energy. It is one of the mechanisms for maintaining the stable development of a partially continuous ecosystem that the plant community and ground surface dissipate the erosion energy produced by surface runoff so as to control the soil erosion process of the ecosystem. Based on the energy fundamentals of hydraulics and by idealizing the structure of plant community, we obtain an ecological hydraulic model in this paper through a series of mathematical deductions, which includes three equations: (1) the equation on approaching energy balance of surface runoff moving across plant community and ground surface; (2) the equation on the process of dissipating energy of surface runoff by plant community and ground surface in an ecosystem; (3) the equation on the relationship among the pattern of plant community, ground surface and energy dissipation of surface runoff. Theoretically, the ecological hydraulic model can be used to calculate the dynamical process of energy dissipation of surface runoff by plant community and ground surface in a partially continuous ecosystem and to discuss the optimization of plant community pattern in a given section of the ecosystem.

scholarly journals Blasting Impact Simulation Test and Fragmentation Distribution Characteristics in an Open-Pit Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaohua Ding ◽  
Xiang Lu ◽  
Wei Zhou ◽  
Xuyang Shi ◽  
Boyu Luan ◽  
...  
Keyword(s):  
Coal Mine ◽  
Wave Attenuation ◽  
Split Hopkinson Pressure Bar ◽  
Impact Load ◽  
Large Diameter ◽  
Test System ◽  
Open Pit ◽  
Hopkinson Pressure Bar ◽  
The Impact ◽  
The Relationship

Based on the split Hopkinson pressure bar (SHPB) test system, dynamic impact tests of coal specimens under different impact pressures were carried out to study the relationship between the impact load and the size of crushed lump coal. Based on the theory of stress wave attenuation, the relationship between the blasting impact load in a single-hole blasting area of a coal seam and the load applied in an impact failure test of a coal specimen in the laboratory was established. According to the characteristics of the fragmentation distribution of the coal specimens destroyed under a laboratory impact load and the requirement of the minimum cost control of coal blasting in an open-pit coal mine, the fragmentation size range was divided into three groups: large-diameter, medium-diameter, and powder particles. Based on this range, the variation rule of the mass percentage of coal fragments with impact pressure was obtained. Established on the evaluation principle of the blasting effect in an open-pit coal mine, a good impact fragmentation effect was obtained. The good pressure range is 0.30 MPa≤P<0.90 MPa.

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