Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam...Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam with low permeability;(3) unstable overlying coal seam without suitable conditions for implementing conventional mining techniques for protective coal seam; and(4) predominant reliance on ‘‘under three" coal resources to ensure production output. This study proposes an integrated, closed-cycle mining-dressing-gas draining-backfilling-mining(MDGBM) technique. The proposed approach involves the mining of protective coal seam, underground dressing of coal and gangue(UDCG), pressure relief and gas drainage before extraction, and backfilling and mining of the protected coal seam. A system for draining gas and mining the protective seam in the rock stratum is designed and implemented based on the geological conditions. This system helps in realizing pressure relief and gas drainage from the protective seam before extraction. Accordingly, another system, which is connected to the existing production system, is established for the UDCG based on the dense medium-shallow trough process. The mixed mining workface is designed to accommodate both solid backfill and conventional fully mechanized coal mining, thereby facilitating coal mining, USCG, and backfilling. The results show that: The mixed mining workface length for the Ji15-31010 protected seam was 220 m with coal production capacity 1.2 million tons per year, while the backfill capacity of gangue was 0.5 million tons per year. The gas pressure decreased from 1.78 to 0.35 MPa, and the total amount of safely mined coal was 1.34 million tons. The process of simultaneously exploiting coal and draining gas was found to be safe, efficient, and green.This process also yielded significant economic benefits.展开更多
According with the request of sustainable development for asset maintenance, in this paper the research state of China and other countries are indexed; then the contents of green maintenance were described and a syste...According with the request of sustainable development for asset maintenance, in this paper the research state of China and other countries are indexed; then the contents of green maintenance were described and a system model of green maintenance was established. This paper discussed in brief the problems needing research, key techniques and adoptable methods of green maintenance.展开更多
With the rapid development of agricultural industry, people have higher and higher requirements for the safety and quality of agricultural products, and rice, as one of the traditional food crops in China, has also re...With the rapid development of agricultural industry, people have higher and higher requirements for the safety and quality of agricultural products, and rice, as one of the traditional food crops in China, has also received extensive attention. Rice is the main food crop in China and plays an important role in Chinas agricultural production. Whether rice is planted green or not will have a significant impact on peoples health, and green rice planting will gradually become the future development trend of rice production. At present, the green ecological technology is developing rapidly in China, and the rice planting technology in China is constantly improving and perfecting, which can not only realize the greening and scale of rice production, but also improve the quality of rice planting and realize the sustainable development and progress of Chinas agriculture. In this paper, taking Donglan County as the main research background, the cultivation points and popularization measures of rice green high-yield technology are analyzed, which will provide theoretical basis for further popularization of rice green high-yield technology.展开更多
In this paper, the effects of a quay or a solid jetty on hydrodynamic coefficients and vertical wave excitation forces on a ship with or without forward speed are discussed. A modified simple Green function technique ...In this paper, the effects of a quay or a solid jetty on hydrodynamic coefficients and vertical wave excitation forces on a ship with or without forward speed are discussed. A modified simple Green function technique is used to calculate the 2D coefficients while the strip theory is used to calculate the 3D coefficients. Wave excitation forces are also calculated with the strip theory. Numerical results are provided for hydrodynamic coefficients and vertical wave excitation forces on a 200 000 DWT tanker ship. It is found that the quay has a considerable effect on the hydrodynamic coefficients and wave excitation forces for a ship.展开更多
At present,there is an increasing demand for natural bioactive compounds able to provide health benefits when included and consumed in a functional food or in a nutraceutical.In this regard,microalgae are promising na...At present,there is an increasing demand for natural bioactive compounds able to provide health benefits when included and consumed in a functional food or in a nutraceutical.In this regard,microalgae are promising natural sources with great potential,not only considering that these organisms are largely underexplored,but also because microalgae can be produced at large scale and their chemical composition might be tuned to over-synthesize a particular target compound.The use of advanced sustainable extraction techniques to recover these bioactive compounds is a must nowadays.This work presents an overview on the use of compressed fluid-based extraction techniques to obtain bioactive compounds from microalgae that can be seen also as a first step towards its recovery at larger scale.When relevant,the description of the analytical procedure used to chemically characterize the bioactive compounds is also included.展开更多
The movement of interacting faults within the Earth’s crust during earthquakes may cause significant structural damage.Large earthquake fault surfaces are often planar or a combination of several planar fault segment...The movement of interacting faults within the Earth’s crust during earthquakes may cause significant structural damage.Large earthquake fault surfaces are often planar or a combination of several planar fault segments.This study analyses the interaction between a non-planar and a planar fault,where the faults are inclined,buried,creeping and strike-slip in nature.The non-planar fault is infinite and formed by two interconnected planar segments,while the planar fault is finite.The present analysis adduces the movement of interacting faults in a composite structure comprised of an elastic layer nested on a visco-elastic substrate of Maxwell medium.The significant effect of various affecting parameters viz.inclination of the faults,velocity of the fault movement,depth of the faults from the free surface,distance between the faults and the non-planarity of the fault has been discussed and also compared.The amount of stress and surface shear strain is restored after the creeping movement.The graphical representation of the effect of non-planarity of the fault on stress-strain accumulation has been established.Analytical solutions are obtained using Laplace transform and Green’s function techniques,supported by numerical simulations.The obtained results provide insights into fault interaction process and have important implications for assessing seismic hazard potential in viscoelastic media.The study of such earthquake fault dynamical models may give some ideas about the nature of stress-strain accumulation or release in the system and help us to observe the mechanism of lithosphere-asthenosphere boundary.展开更多
基金supported by the Qing Lan Project Foundation of Jiangsu Province in 2014,Foundation for Distinguished professor of Jiangsu Province in 2015,Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51421003)Project funded by China Postdoctoral Science Foundation(2016M601915)National Key Basic Research Program of China(No.2013CB227905)
文摘Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam with low permeability;(3) unstable overlying coal seam without suitable conditions for implementing conventional mining techniques for protective coal seam; and(4) predominant reliance on ‘‘under three" coal resources to ensure production output. This study proposes an integrated, closed-cycle mining-dressing-gas draining-backfilling-mining(MDGBM) technique. The proposed approach involves the mining of protective coal seam, underground dressing of coal and gangue(UDCG), pressure relief and gas drainage before extraction, and backfilling and mining of the protected coal seam. A system for draining gas and mining the protective seam in the rock stratum is designed and implemented based on the geological conditions. This system helps in realizing pressure relief and gas drainage from the protective seam before extraction. Accordingly, another system, which is connected to the existing production system, is established for the UDCG based on the dense medium-shallow trough process. The mixed mining workface is designed to accommodate both solid backfill and conventional fully mechanized coal mining, thereby facilitating coal mining, USCG, and backfilling. The results show that: The mixed mining workface length for the Ji15-31010 protected seam was 220 m with coal production capacity 1.2 million tons per year, while the backfill capacity of gangue was 0.5 million tons per year. The gas pressure decreased from 1.78 to 0.35 MPa, and the total amount of safely mined coal was 1.34 million tons. The process of simultaneously exploiting coal and draining gas was found to be safe, efficient, and green.This process also yielded significant economic benefits.
文摘According with the request of sustainable development for asset maintenance, in this paper the research state of China and other countries are indexed; then the contents of green maintenance were described and a system model of green maintenance was established. This paper discussed in brief the problems needing research, key techniques and adoptable methods of green maintenance.
文摘With the rapid development of agricultural industry, people have higher and higher requirements for the safety and quality of agricultural products, and rice, as one of the traditional food crops in China, has also received extensive attention. Rice is the main food crop in China and plays an important role in Chinas agricultural production. Whether rice is planted green or not will have a significant impact on peoples health, and green rice planting will gradually become the future development trend of rice production. At present, the green ecological technology is developing rapidly in China, and the rice planting technology in China is constantly improving and perfecting, which can not only realize the greening and scale of rice production, but also improve the quality of rice planting and realize the sustainable development and progress of Chinas agriculture. In this paper, taking Donglan County as the main research background, the cultivation points and popularization measures of rice green high-yield technology are analyzed, which will provide theoretical basis for further popularization of rice green high-yield technology.
文摘In this paper, the effects of a quay or a solid jetty on hydrodynamic coefficients and vertical wave excitation forces on a ship with or without forward speed are discussed. A modified simple Green function technique is used to calculate the 2D coefficients while the strip theory is used to calculate the 3D coefficients. Wave excitation forces are also calculated with the strip theory. Numerical results are provided for hydrodynamic coefficients and vertical wave excitation forces on a 200 000 DWT tanker ship. It is found that the quay has a considerable effect on the hydrodynamic coefficients and wave excitation forces for a ship.
基金ABACUS(Algae for a Biomass Applied to the produCtion of added value compounds,grant agreement No 745668the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme)and AGL2017-89417-R(MINECO,Spain)for financial support.
文摘At present,there is an increasing demand for natural bioactive compounds able to provide health benefits when included and consumed in a functional food or in a nutraceutical.In this regard,microalgae are promising natural sources with great potential,not only considering that these organisms are largely underexplored,but also because microalgae can be produced at large scale and their chemical composition might be tuned to over-synthesize a particular target compound.The use of advanced sustainable extraction techniques to recover these bioactive compounds is a must nowadays.This work presents an overview on the use of compressed fluid-based extraction techniques to obtain bioactive compounds from microalgae that can be seen also as a first step towards its recovery at larger scale.When relevant,the description of the analytical procedure used to chemically characterize the bioactive compounds is also included.
文摘The movement of interacting faults within the Earth’s crust during earthquakes may cause significant structural damage.Large earthquake fault surfaces are often planar or a combination of several planar fault segments.This study analyses the interaction between a non-planar and a planar fault,where the faults are inclined,buried,creeping and strike-slip in nature.The non-planar fault is infinite and formed by two interconnected planar segments,while the planar fault is finite.The present analysis adduces the movement of interacting faults in a composite structure comprised of an elastic layer nested on a visco-elastic substrate of Maxwell medium.The significant effect of various affecting parameters viz.inclination of the faults,velocity of the fault movement,depth of the faults from the free surface,distance between the faults and the non-planarity of the fault has been discussed and also compared.The amount of stress and surface shear strain is restored after the creeping movement.The graphical representation of the effect of non-planarity of the fault on stress-strain accumulation has been established.Analytical solutions are obtained using Laplace transform and Green’s function techniques,supported by numerical simulations.The obtained results provide insights into fault interaction process and have important implications for assessing seismic hazard potential in viscoelastic media.The study of such earthquake fault dynamical models may give some ideas about the nature of stress-strain accumulation or release in the system and help us to observe the mechanism of lithosphere-asthenosphere boundary.
