With the third innovation in science and technology worldwide, China has also experienced thismarvelous progress. Concerning the longwall mining in China, the ＂masonry beam theory＂ （MBT） wasfirst proposed in the 1...With the third innovation in science and technology worldwide, China has also experienced thismarvelous progress. Concerning the longwall mining in China, the ＂masonry beam theory＂ （MBT） wasfirst proposed in the 1960s, illustrating that the transmission and equilibrium method of overburdenpressure using reserved coal pillar in mined-out areas can be realized. This forms the so-called ＂121mining method＂, which lays a solid foundation for development of mining science and technology inChina. The ＂transfer rock beam theory＂ （TRBT） proposed in the 1980s gives a further understanding forthe transmission path of stope overburden pressure and pressure distribution in high-stress areas. In thisregard, the advanced 121 mining method was proposed with smaller coal pillar for excavation design,making significant contributions to improvement of the coal recovery rate in that era. In the 21st century,the traditional mining technologies faced great challenges and, under the theoretical developmentspioneered by Profs. Minggao Qian and Zhenqi Song, the ＂cutting cantilever beam theory＂ （CCBT） wasproposed in 2008. After that the 110 mining method is formulated subsequently, namely one stope face,after the first mining cycle, needs one advanced gateway excavation, while the other one is automaticallyformed during the last mining cycle without coal pillars left in the mining area. This method can beimplemented using the CCBT by incorporating the key technologies, including the directional presplittingroof cutting, constant resistance and large deformation （CRLD） bolt/anchor supporting systemwith negative Poisson＇s ratio （NPR） effect material, and remote real-time monitoring technology. TheCCBT and 110 mining method will provide the theoretical and technical basis for the development ofmining industry in China.展开更多
Since the 1960 s, mining science and technology in China has experienced two technical innovations, i.e.the ‘‘Masonry Beam Theory(MBT)" and ‘‘Transfer Rock Beam Theory(TRBT)". Based on those theories, th...Since the 1960 s, mining science and technology in China has experienced two technical innovations, i.e.the ‘‘Masonry Beam Theory(MBT)" and ‘‘Transfer Rock Beam Theory(TRBT)". Based on those theories, the conventional mining method(being called the 121 mining method) was established, consisting of excavating two tunnels with a pillar left for mining a working panel. However, with increasing mining depth,engineering geological disasters in the underground caverns have been frequently encountered. In addition, the use of the coal-pillar mining results in a large amount of coal resources unexploited. In order to address the problems above, the ‘‘Roof Cut Short-Arm Beam Theory(RCSBT), being called the 110 mining method)" was proposed by He Manchao in 2008. The 110 mining method features the mining of one coal seam panel, excavating necessarily only one roadway tunnel and leaving no pillars. Realization of the 110 mining method includes the following steps:(1) directional pre-splitting roof cutting,(2) supporting the roof by using high Constant Resistance Large Deformation bolt/cable(CRLD), and(3) blocking gangue by hydraulic props. This paper presents an overview of the principles, techniques and application of the 110 mining method. Special emphasis is placed on the numerical simulation of the geostress distribution found in the mining panel using the 110 method compared to that of the 121 method. In addition, the stress distribution on the ‘‘short beam" left by the roof cutting when performing the 110 method was also investigated using both numerical simulation and theoretical formulation.展开更多
Objective:To analyze the component law of Chinese patent medicines for anti-influenza and develop new prescriptions for anti-influenza by unsupervised data mining methods. Methods: Chinese patent medicine recipes for ...Objective:To analyze the component law of Chinese patent medicines for anti-influenza and develop new prescriptions for anti-influenza by unsupervised data mining methods. Methods: Chinese patent medicine recipes for anti-influenza were collected and recorded in the database, and then the correlation coefficient between herbs, core combinations of herbs and new prescriptions were analyzed by using modified mutual information, complex system entropy cluster and unsupervised hierarchical clustering, respectively. Results: Based on analysis of 126 Chinese patent medicine recipes, the frequency of each herb occurrence in these recipes, 54 frequently-used herb pairs, 34 core combinations were determined, and 4 new recipes for influenza were developed. Conclusion: Unsupervised data mining methods are able to mine the component law quickly and develop new prescriptions.展开更多
For the 110 mining method,it is challenging to accurately calculate the support resistance of the roadway due to the lack of understanding of the dynamic movement of the overlying strata in this method.The consequenti...For the 110 mining method,it is challenging to accurately calculate the support resistance of the roadway due to the lack of understanding of the dynamic movement of the overlying strata in this method.The consequential excessive support results in a significant increase in the cost of roadway support.The authors explored the overlying strata movement and roadway deformation of the gob-entry retaining in the 110 mining method to solve this problem.First,the typical stages of the roof-cutting gob-side entry were defined.Second,the mechanical model and calculation formula of the support resistance on the roof were explored.Then,using numerical simulation software,the starting ranges of the specific supports at different stages were verified and the feasibility of the support scheme was examined.Finally,combined with the field measurement data,the stress and the deformation of the gob roadway at different stages under the influence of two mining processes in the 110 mining method were obtained.The numerical simulation results obtained are consistent with the field test results,providing a theoretical basis for precision support at different stages by the 110 mining method.展开更多
In the case of unknown weights, theories of multi-attributed decision making based on interval numbers and grey related analysis were used to optimize mining methods. As the representative of independence for the indi...In the case of unknown weights, theories of multi-attributed decision making based on interval numbers and grey related analysis were used to optimize mining methods. As the representative of independence for the indicator, the smaller the correlation of indicators is, the greater the weight is. Hence, the weights of interval numbers of indicators were determined by using correlation coefficient. Relative closeness based on positive and negative ideal methods was calculated by introducing distance between interval numbers, which made decision making more rational and comprehensive. A new method of ranking interval numbers based on normal distribution was proposed for the optimization of mining methods, whose basic properties were discussed. Finally, the feasibility and effectiveness of this method were verified by theories and practice.展开更多
The mining method optimization in subsea deep gold mines was studied. First, an index system for subsea mining method selection was established based on technical feasibility, security status, economic benefit, and ma...The mining method optimization in subsea deep gold mines was studied. First, an index system for subsea mining method selection was established based on technical feasibility, security status, economic benefit, and management complexity. Next, an evaluation matrix containing crisp numbers and triangular fuzzy numbers(TFNs) was constructed to describe quantitative and qualitative information simultaneously. Then, a hybrid model combining fuzzy theory and the Tomada de Decis?o Interativa Multicritério(TODIM) method was proposed. Finally, the feasibility of the proposed approach was validated by an illustrative example of selecting the optimal mining method in the Sanshandao Gold Mine(China). The robustness of this approach was demonstrated through a sensitivity analysis. The results show that the proposed hybrid TODIM method is reliable and stable for choosing the optimal mining method in subsea deep gold mines and provides references for mining method optimization in other similar undersea mines.展开更多
An optimization model of underground mining method selection was established on the basis of the unascertained measurement theory.Considering the geologic conditions,technology,economy and safety production,ten main f...An optimization model of underground mining method selection was established on the basis of the unascertained measurement theory.Considering the geologic conditions,technology,economy and safety production,ten main factors influencing the selection of mining method were taken into account,and the comprehensive evaluation index system of mining method selection was constructed.The unascertained evaluation indices corresponding to the selected factors for the actual situation were solved both qualitatively and quantitatively.New measurement standards were constructed.Then,the unascertained measurement function of each evaluation index was established.The index weights of the factors were calculated by entropy theory,and credible degree recognition criteria were established according to the unascertained measurement theory.The results of mining method evaluation were obtained using the credible degree criteria,thus the best underground mining method was determined.Furthermore,this model was employed for the comprehensive evaluation and selection of the chosen standard mining methods in Xinli Gold Mine in Sanshandao of China.The results show that the relative superiority degrees of mining methods can be calculated using the unascertained measurement optimization model,so the optimal method can be easily determined.Meanwhile,the proposed method can take into account large amount of uncertain information in mining method selection,which can provide an effective way for selecting the optimal underground mining method.展开更多
Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the fac...Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.展开更多
One of the most critical and complicated steps in mine design is a selection of suitable mining method based upon geological,geotechnical,geographical,safety and economical parameters.The aim of this study is developi...One of the most critical and complicated steps in mine design is a selection of suitable mining method based upon geological,geotechnical,geographical,safety and economical parameters.The aim of this study is developing a Monte Carlo simulation to selection the optimum mining method by using effective and major criteria and at the same time,taking subjective judgments of decision makers into consideration.Proposed approach is based on the combination of Monte Carlo simulation with conventional Analytic Hierarchy Process(AHP).Monte Carlo simulation is used to determine the confdence level of each alternative’s score,is calculated by AHP,with the respect to the variance of decision makers’opinion.The proposed method is applied for Jajarm Bauxite Mine in Iran and eventually the most appropriate mining methods for this mine are ranked.展开更多
The influence of mining method tunnel construction on the groundwater environment is a very important and complex engineering environment problem, and the strong differential weathering of water-rich granite strata in...The influence of mining method tunnel construction on the groundwater environment is a very important and complex engineering environment problem, and the strong differential weathering of water-rich granite strata increases the difficulty of this problem. In this paper, the mineral composition and microstructure characteristics of granite with different weathering degrees before and after the influence of mining method were studied by <em>in-situ</em> and indoor seepage tests and theoretical calculation, and the impact of mining method tunneling on granite permeability was also analyzed. Calculation results revealed that the permeability coefficient of surrounding rock at 1.1 m away from excavation face increased 41.6 times as much as the original. The permeability coefficient of moderately and strongly weathered granite increased by 6.12 and 3.33 times, respectively and the permeability also increased. The variation of the permeability coefficient of fully weathered granite was the smallest, increasing by 1.67 times, which is due to mechanical excavation of a fully weathered layer on-site, and the disturbance was far less than that caused by blasting. The scale of the excavation damaged zone (EDZ) induced by mining method was determined by wave velocity test, which provides a basis for subsequent seepage field calculation and research.展开更多
In actual space, considering the heterogeneity and anisotropy of rock and soil, the difference of hydrogeological conditions and the influence of tunnel excavation, tunnel seepage problem is a very complex three-dimen...In actual space, considering the heterogeneity and anisotropy of rock and soil, the difference of hydrogeological conditions and the influence of tunnel excavation, tunnel seepage problem is a very complex three-dimensional seepage problem, which is very difficult to solve. The equivalent continuum model is one of the most commonly simplified models used in solving tunnel seepage problems. In this paper, the finite element software ABAQUS and the research results are used to establish a seepage numerical calculation model, study the influence of mining method construction on the seepage field in weathered granite, and clarify the influence of each stage of mining method construction on the groundwater environment. On this basis, the sensitivity of the seepage field to various factors such as natural environment, engineering geology and hydrogeology, tunnel construction and so on is analyzed, which provides a basis to establish the evaluation system of groundwater environment negative effect in weathered granite stratum by mining method tunnel construction.展开更多
The paper presents the mining method for the close quarter coal seams with thin rock sheet, that is mining the low coal seam, recovering the top coal seam after putting down the roof rock of the low coal seam. Practic...The paper presents the mining method for the close quarter coal seams with thin rock sheet, that is mining the low coal seam, recovering the top coal seam after putting down the roof rock of the low coal seam. Practice has proved that in recovering the top coal outside the face width after the rock between seams falls naturally or is demolished, the technology is simple, easy to operate and does not make a great demand for technical equipment. In the process of recovering the top coal, the low seam support could not be affected seriously, and two seams mining could be coordinated. Compared with the individual mining method, this mining method can produce a better economic benefit.展开更多
China＇s total coal reserves are enormous, in which recoverable reserves of coal seam thickness ofmineable coal reserves in China accounted for 43% of recoverable reserves When correctly using thick seam mining, minin...China＇s total coal reserves are enormous, in which recoverable reserves of coal seam thickness ofmineable coal reserves in China accounted for 43% of recoverable reserves When correctly using thick seam mining, mining methods can improve the proper thick seam mining rate and reduce coal loss. Using proper thick seam mining method can effectively reduce the thick seam mining costs. In mining safety, the use of appropriate thick seam mining methods can effectively prevent thick seam mining accidents. But in the process of development and current situation from the perspective of the Chinese coal mining, there are certain aspects of thick seam mining problems. These problems are mainly in the thick seam mining and the coal recovery rate is low, resulting in lots of waste coal. Besides, thick coal mining is less secure, safe and there are frequent accidents. These problems have seriously affected the thick seam mining. And a lot of thick coal seams of coal resources can not be effectively taken out. Now Chinese mining methods in thick seam mining areas are mainly open-pit mining and underground mining exploitation. Because of the open-pit coal burial depth has more stringent requirements, only used in shallow-depth areas. Underground mining is the primary way China is now using in thick seam mining. Underground mining methods include full-height slice mining and mechanized mining caving mining method once adopted. Research on these thick seam mining methods can provide theoretical and technical support for thick seam mining, thick seam mining techniques to enhance the level . I will combine the current situation of thick seam mining in Chinese study with thick seam mining methods, comments and suggestions for the current thick seam mining study展开更多
Artisanal and Small-Scale Gold Mining(ASGM)operations are known to contribute significantly towards rural economic development.The operations which are widespread in about 80 countries across Africa,Asia,Oceania,Centr...Artisanal and Small-Scale Gold Mining(ASGM)operations are known to contribute significantly towards rural economic development.The operations which are widespread in about 80 countries across Africa,Asia,Oceania,Central and South America have the potentials to alleviate poverty,create employment opportunities,generate income and produce large quantities of the precious mineral gold.In spite of all these potentials,the sector is associated with high levels of environmental degradation,health and safety threats and low productivity that threaten the sustainability of the sector.These challenges have been linked to the use of inappropriate mining methods for the various deposit types exploited.In mining engineering principle,the selection of a suitable mining method for a particular ore deposit is critical for the environmental,safety and economic sustainability of a mining project.However,little attention has been given to the subject of sustainable mining methods for ASGM operations.This study seeks to fill the gap in science by developing safe and sustainable mining methods for ASGM operations exploiting alluvial or colluvial deposits with hard rock potentials.These particular deposit types have been chosen because they are the most exploited deposit types by ASGM miners.The methods used in conducting this study include literature review of the occurrence of these deposit types.Field visits to 3 ASGM sites in Ghana exploiting these deposit types and evaluation of the challenges regarding the mining methods being used.The development and design of the mining methods were done using Surpac 6.6.2 software and design tools in Microsoft Power-Point.Results from the study indicated that there is a gap in literature regarding ASGM mining methods and a gap in the miners'knowledge about the appropriate mining methods tailored for their deposit types.Moreover,the wide pits which were used to exploit the deposits posed safety risks,had low productivity and limited access to deeper hard rock deposits.This study aims to bridge the existing knowledge gap by developing the Bench Pit-Underground Mining(BPUM)method,designed specifically for ASGM operations exploiting these deposit types.It is therefore recommended ASGM operations adopt the BPUM method to ensure safety,increased productivity and sustainability in their operations.展开更多
The non-pillar mining method with automatically formed roadway(NPM-AFR)is an innovative mining method.This paper provides a detailed description of how this method achieves the cancellation of pillar retention and the...The non-pillar mining method with automatically formed roadway(NPM-AFR)is an innovative mining method.This paper provides a detailed description of how this method achieves the cancellation of pillar retention and the advance excavation of roadways through optimized mining processes.Based on mining mechanics modeling,the paper explains how the NPM-AFR compensates for mining-induced damage by utilizing the bulking of the goaf gangue and uses directional roof cutting technology interrupt the stress transmission path from the goaf to the roadway,thereby enhancing the protection of both the overlying strata and the roadway.Geological and mechanical model tests were conducted based on the Ningtiaota coal mine to compare the NPM-AFR and traditional mining method.The results show that under the NPM-AFR,the development height of overlying strata damage is reduced by 36.14%compared to traditional mining method,and overlying strata stress is reduced by 25%.The overlying strata is effectively protected in the NPM-AFR mining area.In both mining methods,the roadways remain in a low-stress zone,but the peak stress on the coal pillar side in the NPM-AFR is reduced by 40.6%compared to the traditional method,significantly reducing the safety risks of the roadway.Field verification tests further demonstrate that the NPM-AFR,along with its supporting processes,successfully achieves the goals of pillar-free mining,surface protection,and safe roadway preservation.This technology represents a sustainable,green mining approach that protects both the overburden and the roadway,providing new solutions for safe and efficient coal mining.展开更多
Water vapor permeability of building materials is a crucial parameter for analysing and optimizing the hygrothermal performance of building envelopes and built environments.Its measurement is accurate but time-consumi...Water vapor permeability of building materials is a crucial parameter for analysing and optimizing the hygrothermal performance of building envelopes and built environments.Its measurement is accurate but time-consuming,while data mining methods have the potential to predict water vapor permeability efficiently.In this study,six data mining methods—support vector regression(SVR),decision tree regression(DT),random forest regression(RF),K-nearest neighbor(KNN),multi-layer perceptron(MLP),and adaptive boosting regression(AdaBoost)—were compared to predict the water vapor permeability of cement-based materials.A total of 143 datasets of material properties were collected to build prediction models,and five materials were experimentally determined for model validation.The results show that RF has excellent generalization,stability,and precision.AdaBoost has great generalization and precision,only slightly inferior to the former,and its stability is excellent.DT has good precision and acceptable generalization,but its stability is poor.SVR and KNN have superior stability,but their generalization and precision are inadequate.MLP lacks generalization,and its stability and precision are unacceptable.In short,RF has the best comprehensive performance,demonstrated by a limited prediction deviation of 26.3%from the experimental results,better than AdaBoost(38.0%)and DT(38.3%)and far better than other remaining methods.It is also found that data mining methods provide better predictions when cement-based materials’water vapor permeability is high.展开更多
Objective： To provide the distribution pattern and compatibility laws of the constituent herbs in prescriptions, for doctor＇s convenience to make decision in choosing correct herbs and prescriptions for treating res...Objective： To provide the distribution pattern and compatibility laws of the constituent herbs in prescriptions, for doctor＇s convenience to make decision in choosing correct herbs and prescriptions for treating respiratory disease. Methods： Classical prescriptions treating respiratory disease were selected from authoritative prescription books. Data mining methods （frequent itemsets and association rules） were used to analyze the regular patterns and compatibility laws of the constituent herbs in the selected prescriptions. Results： A total of 562 prescriptions were selected to be studied. The result exhibited that, Radix g/ycyrrhizae was the most frequently used in 47.2% prescriptions, other frequently used were Semen armeniacae amarum, Fructus schisandrae Chinese, Herba ephedrae, and Radix ginseng. Herbal ephedrae was always coupled with Semen armeniacae amarum with the confidence of 73.3%, and many herbs were always accompanied by Radix g/ycyrrhizae with high confidence. More over, Fructus schisandrae Chinese, Herba ephedrae and Rhizoma pinelliae was most commonly used to treat cough, dyspnoea and associated sputum respectively besides Radix glycyrrhizae and Semen armeniacae amarum. The prescriptions treating dyspnoea often used double herb group of Herba ephedrae ＆ Radix glycyrrhizae, while prescriptions treating sputum often used double herb group of Rhizoma pinel/iae ＆ Radix glycyrrhizae and Rhizoma pinelliae ＆ Semen armeniacae amarum, triple herb groups of Rhizoma pinelliae ＆ Semen armeniacae amarum ＆ Radix glycyrrhizae and Pericarpium citri reticu/atae ＆ Rhizoma pine/liae ＆ Radix glycyrrhizae. Couclusioas： The prescriptions treating respiratory disease showed common compatibility laws in using herbs and special compatibility laws for treating different respiratory symptoms. These principle patterns and special compatibility laws reported here could be useful for doctors to choose correct herbs and prescriptions in treating respiratory disease.展开更多
A new probability function of mining overlying strata and subsidence is put forward that has a general statistical significance based on the ideal stochastic medium displacement model. It establishes a new system of p...A new probability function of mining overlying strata and subsidence is put forward that has a general statistical significance based on the ideal stochastic medium displacement model. It establishes a new system of prediction on horizontal mining subsidence and deformation, which gives a new method for prediction on mining subsidence and deformation.展开更多
Xinli district of Sanshandao Gold Mine is the first subsea metal mine in China.To achieve 6 kt/d production capacity under the premise of safe mining,high-intensity mining might destroy the in-situ stress filed and th...Xinli district of Sanshandao Gold Mine is the first subsea metal mine in China.To achieve 6 kt/d production capacity under the premise of safe mining,high-intensity mining might destroy the in-situ stress filed and the stability of rockmass.According to sampling and testing of ore-rock and backfill and in-situ stress field measurement,safety factor method calculation model based on stress-strain strength reduction at arbitrary points and Mohr-Coulomb yield criterion was established and limit displacement subsidence values under the safety factor of different limit stoping steps were calculated.The results from three years in-situ mining and strata movement monitoring using multi-point displacements meter showed that the lower settlement frame stope hierarchical level filling mining method,mining sequence are reasonable and rockmass stability evaluation using safety factor method,in-situ real-time monitoring can provide the technical foundation for the safety of seabed mining.展开更多
基金supported by the National Natural Science Foundation of China (No. 51404278)the State Key Program of National Natural Science Foundation of China (No. 51134005)
文摘With the third innovation in science and technology worldwide, China has also experienced thismarvelous progress. Concerning the longwall mining in China, the ＂masonry beam theory＂ （MBT） wasfirst proposed in the 1960s, illustrating that the transmission and equilibrium method of overburdenpressure using reserved coal pillar in mined-out areas can be realized. This forms the so-called ＂121mining method＂, which lays a solid foundation for development of mining science and technology inChina. The ＂transfer rock beam theory＂ （TRBT） proposed in the 1980s gives a further understanding forthe transmission path of stope overburden pressure and pressure distribution in high-stress areas. In thisregard, the advanced 121 mining method was proposed with smaller coal pillar for excavation design,making significant contributions to improvement of the coal recovery rate in that era. In the 21st century,the traditional mining technologies faced great challenges and, under the theoretical developmentspioneered by Profs. Minggao Qian and Zhenqi Song, the ＂cutting cantilever beam theory＂ （CCBT） wasproposed in 2008. After that the 110 mining method is formulated subsequently, namely one stope face,after the first mining cycle, needs one advanced gateway excavation, while the other one is automaticallyformed during the last mining cycle without coal pillars left in the mining area. This method can beimplemented using the CCBT by incorporating the key technologies, including the directional presplittingroof cutting, constant resistance and large deformation （CRLD） bolt/anchor supporting systemwith negative Poisson＇s ratio （NPR） effect material, and remote real-time monitoring technology. TheCCBT and 110 mining method will provide the theoretical and technical basis for the development ofmining industry in China.
文摘Since the 1960 s, mining science and technology in China has experienced two technical innovations, i.e.the ‘‘Masonry Beam Theory(MBT)" and ‘‘Transfer Rock Beam Theory(TRBT)". Based on those theories, the conventional mining method(being called the 121 mining method) was established, consisting of excavating two tunnels with a pillar left for mining a working panel. However, with increasing mining depth,engineering geological disasters in the underground caverns have been frequently encountered. In addition, the use of the coal-pillar mining results in a large amount of coal resources unexploited. In order to address the problems above, the ‘‘Roof Cut Short-Arm Beam Theory(RCSBT), being called the 110 mining method)" was proposed by He Manchao in 2008. The 110 mining method features the mining of one coal seam panel, excavating necessarily only one roadway tunnel and leaving no pillars. Realization of the 110 mining method includes the following steps:(1) directional pre-splitting roof cutting,(2) supporting the roof by using high Constant Resistance Large Deformation bolt/cable(CRLD), and(3) blocking gangue by hydraulic props. This paper presents an overview of the principles, techniques and application of the 110 mining method. Special emphasis is placed on the numerical simulation of the geostress distribution found in the mining panel using the 110 method compared to that of the 121 method. In addition, the stress distribution on the ‘‘short beam" left by the roof cutting when performing the 110 method was also investigated using both numerical simulation and theoretical formulation.
基金supported by Scientific Research Special Project of TCM Profession (200907001E)Science and Technology Special Major Project for "Significant New Drugs Formulation" (2009ZX09301-005-02)
文摘Objective:To analyze the component law of Chinese patent medicines for anti-influenza and develop new prescriptions for anti-influenza by unsupervised data mining methods. Methods: Chinese patent medicine recipes for anti-influenza were collected and recorded in the database, and then the correlation coefficient between herbs, core combinations of herbs and new prescriptions were analyzed by using modified mutual information, complex system entropy cluster and unsupervised hierarchical clustering, respectively. Results: Based on analysis of 126 Chinese patent medicine recipes, the frequency of each herb occurrence in these recipes, 54 frequently-used herb pairs, 34 core combinations were determined, and 4 new recipes for influenza were developed. Conclusion: Unsupervised data mining methods are able to mine the component law quickly and develop new prescriptions.
基金Project(51674265) supported by the National Natural Science Foundation of ChinaProjects(2018YFC0603705,2016YFC0600901) supported by the State Key Research Development Program of ChinaProject supported by the Yueqi Outstanding Scholar Award Program of China University of Mining&Technology,Beijing,China。
文摘For the 110 mining method,it is challenging to accurately calculate the support resistance of the roadway due to the lack of understanding of the dynamic movement of the overlying strata in this method.The consequential excessive support results in a significant increase in the cost of roadway support.The authors explored the overlying strata movement and roadway deformation of the gob-entry retaining in the 110 mining method to solve this problem.First,the typical stages of the roof-cutting gob-side entry were defined.Second,the mechanical model and calculation formula of the support resistance on the roof were explored.Then,using numerical simulation software,the starting ranges of the specific supports at different stages were verified and the feasibility of the support scheme was examined.Finally,combined with the field measurement data,the stress and the deformation of the gob roadway at different stages under the influence of two mining processes in the 110 mining method were obtained.The numerical simulation results obtained are consistent with the field test results,providing a theoretical basis for precision support at different stages by the 110 mining method.
基金Project(50774095) supported by the National Natural Science Foundation of ChinaProject(200449) supported by the National Outstanding Doctoral Dissertations Special Funds of China
文摘In the case of unknown weights, theories of multi-attributed decision making based on interval numbers and grey related analysis were used to optimize mining methods. As the representative of independence for the indicator, the smaller the correlation of indicators is, the greater the weight is. Hence, the weights of interval numbers of indicators were determined by using correlation coefficient. Relative closeness based on positive and negative ideal methods was calculated by introducing distance between interval numbers, which made decision making more rational and comprehensive. A new method of ranking interval numbers based on normal distribution was proposed for the optimization of mining methods, whose basic properties were discussed. Finally, the feasibility and effectiveness of this method were verified by theories and practice.
基金Project(2018dcyj052) supported by Survey Research Funds of Central South University,ChinaProject(51774321) supported by the National Natural Science Foundation of ChinaProject(2018YFC0604606) supported by the National Key Research and Development Program of China
文摘The mining method optimization in subsea deep gold mines was studied. First, an index system for subsea mining method selection was established based on technical feasibility, security status, economic benefit, and management complexity. Next, an evaluation matrix containing crisp numbers and triangular fuzzy numbers(TFNs) was constructed to describe quantitative and qualitative information simultaneously. Then, a hybrid model combining fuzzy theory and the Tomada de Decis?o Interativa Multicritério(TODIM) method was proposed. Finally, the feasibility of the proposed approach was validated by an illustrative example of selecting the optimal mining method in the Sanshandao Gold Mine(China). The robustness of this approach was demonstrated through a sensitivity analysis. The results show that the proposed hybrid TODIM method is reliable and stable for choosing the optimal mining method in subsea deep gold mines and provides references for mining method optimization in other similar undersea mines.
基金Project(2007CB209402) supported by the National Basic Research Program of China Project(SKLGDUEK0906) supported by the Research Fund of State Key Laboratory for Geomechanics and Deep Underground Engineering of China
文摘An optimization model of underground mining method selection was established on the basis of the unascertained measurement theory.Considering the geologic conditions,technology,economy and safety production,ten main factors influencing the selection of mining method were taken into account,and the comprehensive evaluation index system of mining method selection was constructed.The unascertained evaluation indices corresponding to the selected factors for the actual situation were solved both qualitatively and quantitatively.New measurement standards were constructed.Then,the unascertained measurement function of each evaluation index was established.The index weights of the factors were calculated by entropy theory,and credible degree recognition criteria were established according to the unascertained measurement theory.The results of mining method evaluation were obtained using the credible degree criteria,thus the best underground mining method was determined.Furthermore,this model was employed for the comprehensive evaluation and selection of the chosen standard mining methods in Xinli Gold Mine in Sanshandao of China.The results show that the relative superiority degrees of mining methods can be calculated using the unascertained measurement optimization model,so the optimal method can be easily determined.Meanwhile,the proposed method can take into account large amount of uncertain information in mining method selection,which can provide an effective way for selecting the optimal underground mining method.
文摘Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.
文摘One of the most critical and complicated steps in mine design is a selection of suitable mining method based upon geological,geotechnical,geographical,safety and economical parameters.The aim of this study is developing a Monte Carlo simulation to selection the optimum mining method by using effective and major criteria and at the same time,taking subjective judgments of decision makers into consideration.Proposed approach is based on the combination of Monte Carlo simulation with conventional Analytic Hierarchy Process(AHP).Monte Carlo simulation is used to determine the confdence level of each alternative’s score,is calculated by AHP,with the respect to the variance of decision makers’opinion.The proposed method is applied for Jajarm Bauxite Mine in Iran and eventually the most appropriate mining methods for this mine are ranked.
文摘The influence of mining method tunnel construction on the groundwater environment is a very important and complex engineering environment problem, and the strong differential weathering of water-rich granite strata increases the difficulty of this problem. In this paper, the mineral composition and microstructure characteristics of granite with different weathering degrees before and after the influence of mining method were studied by <em>in-situ</em> and indoor seepage tests and theoretical calculation, and the impact of mining method tunneling on granite permeability was also analyzed. Calculation results revealed that the permeability coefficient of surrounding rock at 1.1 m away from excavation face increased 41.6 times as much as the original. The permeability coefficient of moderately and strongly weathered granite increased by 6.12 and 3.33 times, respectively and the permeability also increased. The variation of the permeability coefficient of fully weathered granite was the smallest, increasing by 1.67 times, which is due to mechanical excavation of a fully weathered layer on-site, and the disturbance was far less than that caused by blasting. The scale of the excavation damaged zone (EDZ) induced by mining method was determined by wave velocity test, which provides a basis for subsequent seepage field calculation and research.
文摘In actual space, considering the heterogeneity and anisotropy of rock and soil, the difference of hydrogeological conditions and the influence of tunnel excavation, tunnel seepage problem is a very complex three-dimensional seepage problem, which is very difficult to solve. The equivalent continuum model is one of the most commonly simplified models used in solving tunnel seepage problems. In this paper, the finite element software ABAQUS and the research results are used to establish a seepage numerical calculation model, study the influence of mining method construction on the seepage field in weathered granite, and clarify the influence of each stage of mining method construction on the groundwater environment. On this basis, the sensitivity of the seepage field to various factors such as natural environment, engineering geology and hydrogeology, tunnel construction and so on is analyzed, which provides a basis to establish the evaluation system of groundwater environment negative effect in weathered granite stratum by mining method tunnel construction.
文摘The paper presents the mining method for the close quarter coal seams with thin rock sheet, that is mining the low coal seam, recovering the top coal seam after putting down the roof rock of the low coal seam. Practice has proved that in recovering the top coal outside the face width after the rock between seams falls naturally or is demolished, the technology is simple, easy to operate and does not make a great demand for technical equipment. In the process of recovering the top coal, the low seam support could not be affected seriously, and two seams mining could be coordinated. Compared with the individual mining method, this mining method can produce a better economic benefit.
文摘China＇s total coal reserves are enormous, in which recoverable reserves of coal seam thickness ofmineable coal reserves in China accounted for 43% of recoverable reserves When correctly using thick seam mining, mining methods can improve the proper thick seam mining rate and reduce coal loss. Using proper thick seam mining method can effectively reduce the thick seam mining costs. In mining safety, the use of appropriate thick seam mining methods can effectively prevent thick seam mining accidents. But in the process of development and current situation from the perspective of the Chinese coal mining, there are certain aspects of thick seam mining problems. These problems are mainly in the thick seam mining and the coal recovery rate is low, resulting in lots of waste coal. Besides, thick coal mining is less secure, safe and there are frequent accidents. These problems have seriously affected the thick seam mining. And a lot of thick coal seams of coal resources can not be effectively taken out. Now Chinese mining methods in thick seam mining areas are mainly open-pit mining and underground mining exploitation. Because of the open-pit coal burial depth has more stringent requirements, only used in shallow-depth areas. Underground mining is the primary way China is now using in thick seam mining. Underground mining methods include full-height slice mining and mechanized mining caving mining method once adopted. Research on these thick seam mining methods can provide theoretical and technical support for thick seam mining, thick seam mining techniques to enhance the level . I will combine the current situation of thick seam mining in Chinese study with thick seam mining methods, comments and suggestions for the current thick seam mining study
文摘Artisanal and Small-Scale Gold Mining(ASGM)operations are known to contribute significantly towards rural economic development.The operations which are widespread in about 80 countries across Africa,Asia,Oceania,Central and South America have the potentials to alleviate poverty,create employment opportunities,generate income and produce large quantities of the precious mineral gold.In spite of all these potentials,the sector is associated with high levels of environmental degradation,health and safety threats and low productivity that threaten the sustainability of the sector.These challenges have been linked to the use of inappropriate mining methods for the various deposit types exploited.In mining engineering principle,the selection of a suitable mining method for a particular ore deposit is critical for the environmental,safety and economic sustainability of a mining project.However,little attention has been given to the subject of sustainable mining methods for ASGM operations.This study seeks to fill the gap in science by developing safe and sustainable mining methods for ASGM operations exploiting alluvial or colluvial deposits with hard rock potentials.These particular deposit types have been chosen because they are the most exploited deposit types by ASGM miners.The methods used in conducting this study include literature review of the occurrence of these deposit types.Field visits to 3 ASGM sites in Ghana exploiting these deposit types and evaluation of the challenges regarding the mining methods being used.The development and design of the mining methods were done using Surpac 6.6.2 software and design tools in Microsoft Power-Point.Results from the study indicated that there is a gap in literature regarding ASGM mining methods and a gap in the miners'knowledge about the appropriate mining methods tailored for their deposit types.Moreover,the wide pits which were used to exploit the deposits posed safety risks,had low productivity and limited access to deeper hard rock deposits.This study aims to bridge the existing knowledge gap by developing the Bench Pit-Underground Mining(BPUM)method,designed specifically for ASGM operations exploiting these deposit types.It is therefore recommended ASGM operations adopt the BPUM method to ensure safety,increased productivity and sustainability in their operations.
基金funded by the National Natural Science Foundation of China(52074298 and 42377148)Beijing Municipal Natural Science Foundation(8232056)+1 种基金Guizhou Province science and technology plan project([2020]3008)Liulin Energy and Environment Academician Workstation(2022XDHZ12).
文摘The non-pillar mining method with automatically formed roadway(NPM-AFR)is an innovative mining method.This paper provides a detailed description of how this method achieves the cancellation of pillar retention and the advance excavation of roadways through optimized mining processes.Based on mining mechanics modeling,the paper explains how the NPM-AFR compensates for mining-induced damage by utilizing the bulking of the goaf gangue and uses directional roof cutting technology interrupt the stress transmission path from the goaf to the roadway,thereby enhancing the protection of both the overlying strata and the roadway.Geological and mechanical model tests were conducted based on the Ningtiaota coal mine to compare the NPM-AFR and traditional mining method.The results show that under the NPM-AFR,the development height of overlying strata damage is reduced by 36.14%compared to traditional mining method,and overlying strata stress is reduced by 25%.The overlying strata is effectively protected in the NPM-AFR mining area.In both mining methods,the roadways remain in a low-stress zone,but the peak stress on the coal pillar side in the NPM-AFR is reduced by 40.6%compared to the traditional method,significantly reducing the safety risks of the roadway.Field verification tests further demonstrate that the NPM-AFR,along with its supporting processes,successfully achieves the goals of pillar-free mining,surface protection,and safe roadway preservation.This technology represents a sustainable,green mining approach that protects both the overburden and the roadway,providing new solutions for safe and efficient coal mining.
基金supported by the National Natural Science Foundation of China(No.52178065).
文摘Water vapor permeability of building materials is a crucial parameter for analysing and optimizing the hygrothermal performance of building envelopes and built environments.Its measurement is accurate but time-consuming,while data mining methods have the potential to predict water vapor permeability efficiently.In this study,six data mining methods—support vector regression(SVR),decision tree regression(DT),random forest regression(RF),K-nearest neighbor(KNN),multi-layer perceptron(MLP),and adaptive boosting regression(AdaBoost)—were compared to predict the water vapor permeability of cement-based materials.A total of 143 datasets of material properties were collected to build prediction models,and five materials were experimentally determined for model validation.The results show that RF has excellent generalization,stability,and precision.AdaBoost has great generalization and precision,only slightly inferior to the former,and its stability is excellent.DT has good precision and acceptable generalization,but its stability is poor.SVR and KNN have superior stability,but their generalization and precision are inadequate.MLP lacks generalization,and its stability and precision are unacceptable.In short,RF has the best comprehensive performance,demonstrated by a limited prediction deviation of 26.3%from the experimental results,better than AdaBoost(38.0%)and DT(38.3%)and far better than other remaining methods.It is also found that data mining methods provide better predictions when cement-based materials’water vapor permeability is high.
基金The Chinese Journal of Integrated Traditional and Western Medicine Press and Springer-Verlag Berlin Heidelberg 2012 ＊Supported by the Major State Basic Research Development Program of China （973 Program, No. 2007CB512601）
文摘Objective： To provide the distribution pattern and compatibility laws of the constituent herbs in prescriptions, for doctor＇s convenience to make decision in choosing correct herbs and prescriptions for treating respiratory disease. Methods： Classical prescriptions treating respiratory disease were selected from authoritative prescription books. Data mining methods （frequent itemsets and association rules） were used to analyze the regular patterns and compatibility laws of the constituent herbs in the selected prescriptions. Results： A total of 562 prescriptions were selected to be studied. The result exhibited that, Radix g/ycyrrhizae was the most frequently used in 47.2% prescriptions, other frequently used were Semen armeniacae amarum, Fructus schisandrae Chinese, Herba ephedrae, and Radix ginseng. Herbal ephedrae was always coupled with Semen armeniacae amarum with the confidence of 73.3%, and many herbs were always accompanied by Radix g/ycyrrhizae with high confidence. More over, Fructus schisandrae Chinese, Herba ephedrae and Rhizoma pinelliae was most commonly used to treat cough, dyspnoea and associated sputum respectively besides Radix glycyrrhizae and Semen armeniacae amarum. The prescriptions treating dyspnoea often used double herb group of Herba ephedrae ＆ Radix glycyrrhizae, while prescriptions treating sputum often used double herb group of Rhizoma pinel/iae ＆ Radix glycyrrhizae and Rhizoma pinelliae ＆ Semen armeniacae amarum, triple herb groups of Rhizoma pinelliae ＆ Semen armeniacae amarum ＆ Radix glycyrrhizae and Pericarpium citri reticu/atae ＆ Rhizoma pine/liae ＆ Radix glycyrrhizae. Couclusioas： The prescriptions treating respiratory disease showed common compatibility laws in using herbs and special compatibility laws for treating different respiratory symptoms. These principle patterns and special compatibility laws reported here could be useful for doctors to choose correct herbs and prescriptions in treating respiratory disease.
文摘A new probability function of mining overlying strata and subsidence is put forward that has a general statistical significance based on the ideal stochastic medium displacement model. It establishes a new system of prediction on horizontal mining subsidence and deformation, which gives a new method for prediction on mining subsidence and deformation.
基金Project(10872218) supported by the National Natural Science Foundation of ChinaProject(2010CB732004) supported by the National Key Basic Research Program of China+1 种基金Project(20090461022) supported by the National Postdoctoral Foundation of ChinaProject (11MX21) supported by the Students' Innovation Project Aubsidize Award of Arcelor Mittal
文摘Xinli district of Sanshandao Gold Mine is the first subsea metal mine in China.To achieve 6 kt/d production capacity under the premise of safe mining,high-intensity mining might destroy the in-situ stress filed and the stability of rockmass.According to sampling and testing of ore-rock and backfill and in-situ stress field measurement,safety factor method calculation model based on stress-strain strength reduction at arbitrary points and Mohr-Coulomb yield criterion was established and limit displacement subsidence values under the safety factor of different limit stoping steps were calculated.The results from three years in-situ mining and strata movement monitoring using multi-point displacements meter showed that the lower settlement frame stope hierarchical level filling mining method,mining sequence are reasonable and rockmass stability evaluation using safety factor method,in-situ real-time monitoring can provide the technical foundation for the safety of seabed mining.
