1.Objective A graphite deposit has been discovered in Sujiquan, Xinjiang in 1980s,which provides detailed geological settings for the super-large graphite deposit discovered in Huangyangshan pluton with total reserves...1.Objective A graphite deposit has been discovered in Sujiquan, Xinjiang in 1980s,which provides detailed geological settings for the super-large graphite deposit discovered in Huangyangshan pluton with total reserves up to 7.264×10^9 t in 2017.Outcrops of igneous rocks in the study area include Middle Devonian plagioclase granite and Late Carboniferous alkali feldspar granite that is referred to the Huangyangshan pluton,which includes the Lower Carboniferous Heishantou Formation and Jiangbasi Formation,both of which consist of volcanic-sedimentary rocks (Fig.1).Sujiquan fault provided passage for the migration of volcanic intrusions.Graphite deposits are usually hosted by metamorphic rocks,but Huangyanshan deposits are hosted by granite rocks,which are rarely known.The Huangyangshan graphite deposit hosted by granite pluton at Huangyangshan area was discovered by Xinjiang Branch of China National Geological Exploration Center of Building Materials Industry since 2015.展开更多
The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining condition.Based on the in-site geological conditions of Longgu coal mine,this paper us...The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining condition.Based on the in-site geological conditions of Longgu coal mine,this paper used the dynamic module of FLAC3D to study the response characteristics of deep super-large section chamber under dynamic and static combined loading condition.Results showed that under the static loading condition,the maximum vertical stress,deformation and failure range are large,where the stress concentration coefficient is 1.64.The maximum roof-to-floor and two-sides deformations are 54.6 mm and 53.1 mm,respectively.Then,under the dynamic and static combined loading condition:(1)The influence of dynamic load frequency on the two-sides is more obvious;(2)The dynamic load amplitude has the greatest influence on the stress concentration degree,and the plastic failure tends to develop to the deeper;(3)With the dynamic load source distance increase,the response of surrounding rock is gradually attenuated.On this basis,empirical equations for each dynamic load conditions were obtained by using regression analysis method,and all correlation coefficients are greater than 0.99.This research provided reference for the supporting design of deep super-large section chamber under same or similar conditions.展开更多
The stress concentration and failure at chamber intersections in coal mine are intense,especially in deepburied,super-large section conditions.In this paper,the plastic radius of super-large section chamber under uneq...The stress concentration and failure at chamber intersections in coal mine are intense,especially in deepburied,super-large section conditions.In this paper,the plastic radius of super-large section chamber under unequal pressure was corrected on the basis of the size effect.Then,stress and failure evolution of intersections under different crossing angles and equivalent angular bisectors were revealed.Furthermore,2 trajectory curves of failure and stress were analytically expressed,which divided the intersection into 5 influencing zones in the light of stress superposition degree.After determining instability trigger point and instability path,instability energy criterion of intersection can be obtained as K>1,which means that the external energy is greater than the sum of energy consumed by surrounding rock instability and supporting structure failure.Taking coal-gangue separation system of Longgu Coal Mine as example,it was found that there was instability risk under original parameters.For long-term stability,an optimization design method was proposed by considering safety factor,and optimal support scheme was obtained.Field monitoring showed intersections deformations were relatively small with the maximum of 125 mm,which verified the rationality of theoretical analysis.This study provides guidance for the stability control of the intersections under the same or similar conditions.展开更多
Bainiuchang silver-polymetallic ore deposit is located in the southeast Yunnan tin-polymetallic metallogenic belt.The probable reserves and inferred resources of the deposit are of 6 470 t Ag and 1.10 Mt Pb and 1.72 M...Bainiuchang silver-polymetallic ore deposit is located in the southeast Yunnan tin-polymetallic metallogenic belt.The probable reserves and inferred resources of the deposit are of 6 470 t Ag and 1.10 Mt Pb and 1.72 Mt Zn and 86 kt Sn.Orebodies of the deposit occur in clastic-carbonate rocks of Tianpeng Formation and Longha Formation of the middle Cambrian System above the Bainiuchang concealed granite of the late Yanshan period.The concealed granite has the characteristics of tin-bearing granites.Abundance of the mineralization elements Sn,Cu,Zn,Pb,Ag and Sb is high in the granitic rocks.Sulphur isotope data of the metal sulphides indicate that most sulphur is derived from the magmas.The ores are similar in rare earth element(REE)patterns to the granitic rocks.The granitic magma activity results in ore-bearing structures.Rocks of the Middle Cambrian System above the concealed intrusion suffer from skarnization,hornfelsing,marbleization,siliconizing and carbonatization.The mineralization elements Sn,Cu,Zn,Pb,Ag and Sb successively appear from the top of the granite to surrounding rocks.These evidences indicate that the granitic magmatism is the principal mineralization factor.The opinion that the south Bainiuchang ore field and the north Awei ore block are tin and copper potential exploration areas was put forward and was verified by drilling tests.展开更多
Objective The Songpan-Garze Fold Belt(SGFB),located in the eastern part of the Tibet Plateau and west of the Sichuan Basin,is an important pegmatite province in China.Some famous pegmatite type deposits occur in the S...Objective The Songpan-Garze Fold Belt(SGFB),located in the eastern part of the Tibet Plateau and west of the Sichuan Basin,is an important pegmatite province in China.Some famous pegmatite type deposits occur in the SGFB,including the Xuebaoding,Jiajika,Keeryin rare metal deposits and Danba muscovite deposit(Li Jiankang et al.,2015).The newly discovered super-large Lijiagou展开更多
Objective The Huashi Village in Xinglong County of Hebei Province is located in the Yanshan subsidence zone in the central eastern North China Plate, which is 137 km away from Beijing City （Fig. la）. This area has ...Objective The Huashi Village in Xinglong County of Hebei Province is located in the Yanshan subsidence zone in the central eastern North China Plate, which is 137 km away from Beijing City （Fig. la）. This area has undergone large -scale magmatic intrusion affected by the tectonic compression of the Pacific Plate in the Mesozoic （known as the Yanshanian movement） to form many alkaline rocks such as the Wulingshan rock mass. Previous studies have conducted petrological research and reconnaissance survey of rare metal ores in this area （Tian Shuzhang and Guo Zongshan, 1981; Xu Baoling et al., 1996）. In 2016, the Qinhuangdao Mineral and Hydrology Engineering Geological Brigade of Hebei Bureau of Geology and Mineral Resources Exploration implemented the project of Reconnaissance of Rare Metal Ores Including Rubidium in Huashi Village of Xinglong County, Hebei Province, and discovered super-large rare metal deposits of rubidium and biobium in the Madi alkali feldspar granite bodies in the Huashi Village to achieve great breakthrough of rare metal ore prospecting.展开更多
Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formula...Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formulas of fluctuating wind-induced responses and equivalent static wind loads(ESWLSs)were derived based on structural dynamics and random vibration theory.The consistent coupled method(CCM)was presented to compensate the coupled term between background and resonant response.Taking the super-large cooling tower(H=215 m)of nuclear power plant in Jiangxi Province,China,which is the highest and largest in China,as the example,based on modified equivalent beam-net design method,the aero-elastic model for simultaneous pressure and vibration measurement of super-large cooling tower is firstly carried out.Then,combining wind tunnel test and CCM,the effects of self-excited force on the surface pressures and wind-induced responses are discussed,and the wind-induced response characteristics of background component,resonant component,coupled term between background and resonant response,fluctuating responses,and wind vibration coefficients are discussed.It can be concluded that wind-induced response mechanism must be understood to direct the wind resistant design for super-large cooling towers.展开更多
During 2015, gold prospecting in Laizhou City of Shandong Peninsula in China has achieved a major breakthrough. Deposits containing 470 and 389 tons of gold metal were discovered in the northern sea area of Sanshandao...During 2015, gold prospecting in Laizhou City of Shandong Peninsula in China has achieved a major breakthrough. Deposits containing 470 and 389 tons of gold metal were discovered in the northern sea area of Sanshandao and the Shaling area, respectively. As a result, the gold prospective resources in the entire Jiaodong Peninsula have now exceeded 4000 tons, fully indicative of the super-large prospecting potential of the Jiaojia-type deposits.展开更多
Rare metal ore reserves are an important strategic resource, and their metallogenic mechanism and mineralization studies have also been received widespread international attention.
The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Caraj...The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces（belts）, such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type（BIF）, magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type（BIF） as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.展开更多
1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou
The combing process of gill machine is an important link in the wool spinning technology.Inorder to improve the quality of products,it is necessary to study the new autoleveling device whichuses the modern control the...The combing process of gill machine is an important link in the wool spinning technology.Inorder to improve the quality of products,it is necessary to study the new autoleveling device whichuses the modern control theory and microcomputer science.We have to set up a mathematicalmodel for object:As the woolen yarns (both input and output) are complex random process,it issuitable for CARMA (controlled autoregressive-moving average) to describe the object by meansof time series analyses of models.展开更多
The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the fr...The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the friction behavior of fibers,and the difference is largely responsible for the "stick-slip" motion of fibers which causes the drafting waves during drafting.In this paper,it's expected that when a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system,the friction among fibers is dominated by the dynamic friction rather than the static friction,and thus the "stick-slip" motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by an experiment,and it can be applied in developing new spinning drafting device.展开更多
Objective The Beiya super-large Au-rich porphyry deposit(304 t Au,2.4 g/t Au)is located within the western Yangtze craton,to the southeast of the Sanjiang Tethyan Orogen(Fig.1).The ore-forming porphyry is adakitic,cha...Objective The Beiya super-large Au-rich porphyry deposit(304 t Au,2.4 g/t Au)is located within the western Yangtze craton,to the southeast of the Sanjiang Tethyan Orogen(Fig.1).The ore-forming porphyry is adakitic,characterized by high Sr/Y and La/Yb ratios coupled with low Y and Yb contents,and is generally thought to be derived from partial melting of thickened mafic lower crust.The lower crust underneath the western Yangtze craton is mainly composed of ancient crust with Archean ages,juvenile crust resulting from the Neoproterozoic subduction(740–1000 Ma),and late Permian juvenile crust related to the Emeishan mantle plume.Which lower crustal end-member has played a critical role in genesis of the Beiya ore-forming porphyry can be constrained by zircon U-Pb ages of amphibolite xenoliths hosted in the ore-forming porphyry,because these xenoliths represent direct samples of the source.In this study,we present new zircon U-Pb ages of these amphibolite xenoliths to have insight into the nature of the Beiya adakitic porphyry source.展开更多
文摘1.Objective A graphite deposit has been discovered in Sujiquan, Xinjiang in 1980s,which provides detailed geological settings for the super-large graphite deposit discovered in Huangyangshan pluton with total reserves up to 7.264×10^9 t in 2017.Outcrops of igneous rocks in the study area include Middle Devonian plagioclase granite and Late Carboniferous alkali feldspar granite that is referred to the Huangyangshan pluton,which includes the Lower Carboniferous Heishantou Formation and Jiangbasi Formation,both of which consist of volcanic-sedimentary rocks (Fig.1).Sujiquan fault provided passage for the migration of volcanic intrusions.Graphite deposits are usually hosted by metamorphic rocks,but Huangyanshan deposits are hosted by granite rocks,which are rarely known.The Huangyangshan graphite deposit hosted by granite pluton at Huangyangshan area was discovered by Xinjiang Branch of China National Geological Exploration Center of Building Materials Industry since 2015.
基金Project(2018YFC0604703)supported by the National Key R&D Program of ChinaProjects(51804181,51874190)supported by the National Natural Science Foundation of China+3 种基金Project(ZR2018QEE002)supported by the Shandong Province Natural Science Fund,ChinaProject(ZR2018ZA0603)supported by the Major Program of Shandong Province Natural Science Foundation,ChinaProject(2019GSF116003)supported by the Key R&D Project of Shandong Province,ChinaProject(SDKDYC190234)supported by the Shandong University of Science and Technology,Graduate Student Technology Innovation Project,China。
文摘The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining condition.Based on the in-site geological conditions of Longgu coal mine,this paper used the dynamic module of FLAC3D to study the response characteristics of deep super-large section chamber under dynamic and static combined loading condition.Results showed that under the static loading condition,the maximum vertical stress,deformation and failure range are large,where the stress concentration coefficient is 1.64.The maximum roof-to-floor and two-sides deformations are 54.6 mm and 53.1 mm,respectively.Then,under the dynamic and static combined loading condition:(1)The influence of dynamic load frequency on the two-sides is more obvious;(2)The dynamic load amplitude has the greatest influence on the stress concentration degree,and the plastic failure tends to develop to the deeper;(3)With the dynamic load source distance increase,the response of surrounding rock is gradually attenuated.On this basis,empirical equations for each dynamic load conditions were obtained by using regression analysis method,and all correlation coefficients are greater than 0.99.This research provided reference for the supporting design of deep super-large section chamber under same or similar conditions.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(Nos.52174122,52074168 and 51874190)Climbing Project of Taishan Scholar in Shandong Province(No.tspd20210313).
文摘The stress concentration and failure at chamber intersections in coal mine are intense,especially in deepburied,super-large section conditions.In this paper,the plastic radius of super-large section chamber under unequal pressure was corrected on the basis of the size effect.Then,stress and failure evolution of intersections under different crossing angles and equivalent angular bisectors were revealed.Furthermore,2 trajectory curves of failure and stress were analytically expressed,which divided the intersection into 5 influencing zones in the light of stress superposition degree.After determining instability trigger point and instability path,instability energy criterion of intersection can be obtained as K>1,which means that the external energy is greater than the sum of energy consumed by surrounding rock instability and supporting structure failure.Taking coal-gangue separation system of Longgu Coal Mine as example,it was found that there was instability risk under original parameters.For long-term stability,an optimization design method was proposed by considering safety factor,and optimal support scheme was obtained.Field monitoring showed intersections deformations were relatively small with the maximum of 125 mm,which verified the rationality of theoretical analysis.This study provides guidance for the stability control of the intersections under the same or similar conditions.
基金Project(40072032) supported by the National Natural Science Foundation of ChinaProject(2004YX06) supported by the Yunnan Province-Institutes/Universities’ Science and Technology Cooperation Project Item
文摘Bainiuchang silver-polymetallic ore deposit is located in the southeast Yunnan tin-polymetallic metallogenic belt.The probable reserves and inferred resources of the deposit are of 6 470 t Ag and 1.10 Mt Pb and 1.72 Mt Zn and 86 kt Sn.Orebodies of the deposit occur in clastic-carbonate rocks of Tianpeng Formation and Longha Formation of the middle Cambrian System above the Bainiuchang concealed granite of the late Yanshan period.The concealed granite has the characteristics of tin-bearing granites.Abundance of the mineralization elements Sn,Cu,Zn,Pb,Ag and Sb is high in the granitic rocks.Sulphur isotope data of the metal sulphides indicate that most sulphur is derived from the magmas.The ores are similar in rare earth element(REE)patterns to the granitic rocks.The granitic magma activity results in ore-bearing structures.Rocks of the Middle Cambrian System above the concealed intrusion suffer from skarnization,hornfelsing,marbleization,siliconizing and carbonatization.The mineralization elements Sn,Cu,Zn,Pb,Ag and Sb successively appear from the top of the granite to surrounding rocks.These evidences indicate that the granitic magmatism is the principal mineralization factor.The opinion that the south Bainiuchang ore field and the north Awei ore block are tin and copper potential exploration areas was put forward and was verified by drilling tests.
基金funded by the Natural Science Foundation of China (grant No. 41702074)Sichuan Education Department Foundation (grant No. 17ZA0039)+2 种基金Young and Middle-Aged Teacher Foster Program of Chengdu University of Technology (grant No. JXGG201701)Opening Foundation of Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation, Ministry of Land and Resources (grant No. gzck2018003)Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration in Guilin University of Technology (grant No. 12-071-20)
文摘Objective The Songpan-Garze Fold Belt(SGFB),located in the eastern part of the Tibet Plateau and west of the Sichuan Basin,is an important pegmatite province in China.Some famous pegmatite type deposits occur in the SGFB,including the Xuebaoding,Jiajika,Keeryin rare metal deposits and Danba muscovite deposit(Li Jiankang et al.,2015).The newly discovered super-large Lijiagou
基金financially supported by the project of Reconnaissance of Rare Metal Ores Including Rubidium in Huashi Village of Xinglong County, Hebei Province from the Hebei Bureau of Geology and Mineral Resources Exploration (grant No.2015017)
文摘Objective The Huashi Village in Xinglong County of Hebei Province is located in the Yanshan subsidence zone in the central eastern North China Plate, which is 137 km away from Beijing City （Fig. la）. This area has undergone large -scale magmatic intrusion affected by the tectonic compression of the Pacific Plate in the Mesozoic （known as the Yanshanian movement） to form many alkaline rocks such as the Wulingshan rock mass. Previous studies have conducted petrological research and reconnaissance survey of rare metal ores in this area （Tian Shuzhang and Guo Zongshan, 1981; Xu Baoling et al., 1996）. In 2016, the Qinhuangdao Mineral and Hydrology Engineering Geological Brigade of Hebei Bureau of Geology and Mineral Resources Exploration implemented the project of Reconnaissance of Rare Metal Ores Including Rubidium in Huashi Village of Xinglong County, Hebei Province, and discovered super-large rare metal deposits of rubidium and biobium in the Madi alkali feldspar granite bodies in the Huashi Village to achieve great breakthrough of rare metal ore prospecting.
基金Projects(50978203,51208254)supported by the National Natural Science Foundation of ChinaProject(BK2012390)supported by Natural Science Foundation of Jiangsu Province,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formulas of fluctuating wind-induced responses and equivalent static wind loads(ESWLSs)were derived based on structural dynamics and random vibration theory.The consistent coupled method(CCM)was presented to compensate the coupled term between background and resonant response.Taking the super-large cooling tower(H=215 m)of nuclear power plant in Jiangxi Province,China,which is the highest and largest in China,as the example,based on modified equivalent beam-net design method,the aero-elastic model for simultaneous pressure and vibration measurement of super-large cooling tower is firstly carried out.Then,combining wind tunnel test and CCM,the effects of self-excited force on the surface pressures and wind-induced responses are discussed,and the wind-induced response characteristics of background component,resonant component,coupled term between background and resonant response,fluctuating responses,and wind vibration coefficients are discussed.It can be concluded that wind-induced response mechanism must be understood to direct the wind resistant design for super-large cooling towers.
文摘During 2015, gold prospecting in Laizhou City of Shandong Peninsula in China has achieved a major breakthrough. Deposits containing 470 and 389 tons of gold metal were discovered in the northern sea area of Sanshandao and the Shaling area, respectively. As a result, the gold prospective resources in the entire Jiaodong Peninsula have now exceeded 4000 tons, fully indicative of the super-large prospecting potential of the Jiaojia-type deposits.
基金financially supported by the National Natural Science Foundation of China(grant No.41302061)
文摘Rare metal ore reserves are an important strategic resource, and their metallogenic mechanism and mineralization studies have also been received widespread international attention.
基金supported by the National Natural Science Foundation of China (grant No. 40773038the Program of High-level Geological Talents (201309)Youth Geological Talents (201112) of the China Geological Survey
文摘The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces（belts）, such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type（BIF）, magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type（BIF） as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.
文摘1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou
文摘The combing process of gill machine is an important link in the wool spinning technology.Inorder to improve the quality of products,it is necessary to study the new autoleveling device whichuses the modern control theory and microcomputer science.We have to set up a mathematicalmodel for object:As the woolen yarns (both input and output) are complex random process,it issuitable for CARMA (controlled autoregressive-moving average) to describe the object by meansof time series analyses of models.
基金National Natural Science Foundation of China(No.50775034)
文摘The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the friction behavior of fibers,and the difference is largely responsible for the "stick-slip" motion of fibers which causes the drafting waves during drafting.In this paper,it's expected that when a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system,the friction among fibers is dominated by the dynamic friction rather than the static friction,and thus the "stick-slip" motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by an experiment,and it can be applied in developing new spinning drafting device.
基金financially supported by the National Key Research and Development Program of China(grant No.2016YFC0600310)the 973 Project(2015CB452600,2011CB4031006)+2 种基金the National Natural Science Foundation of China(grants No.41872083,41472076)the Program of the China Geological Survey(grants No.DD20160024–07,DD20179172)the China Fundamental Research Funds for the Central Universities(grant No.2652018133).
文摘Objective The Beiya super-large Au-rich porphyry deposit(304 t Au,2.4 g/t Au)is located within the western Yangtze craton,to the southeast of the Sanjiang Tethyan Orogen(Fig.1).The ore-forming porphyry is adakitic,characterized by high Sr/Y and La/Yb ratios coupled with low Y and Yb contents,and is generally thought to be derived from partial melting of thickened mafic lower crust.The lower crust underneath the western Yangtze craton is mainly composed of ancient crust with Archean ages,juvenile crust resulting from the Neoproterozoic subduction(740–1000 Ma),and late Permian juvenile crust related to the Emeishan mantle plume.Which lower crustal end-member has played a critical role in genesis of the Beiya ore-forming porphyry can be constrained by zircon U-Pb ages of amphibolite xenoliths hosted in the ore-forming porphyry,because these xenoliths represent direct samples of the source.In this study,we present new zircon U-Pb ages of these amphibolite xenoliths to have insight into the nature of the Beiya adakitic porphyry source.
