The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization ...The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(< 200 ℃) compatible with boiling conditions. Such results open up perspectives for the development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.展开更多
在网络安全问题中,一种分布式拒绝服务(Distributed deny of services)攻击严重威胁着现有的互联网.针对DDOS攻击基于神经网络算法的防护,因为现有算法收敛性能不高,过滤DDOS攻击包的速度过慢,无法投入大规模商业使用.本文针对这个问题...在网络安全问题中,一种分布式拒绝服务(Distributed deny of services)攻击严重威胁着现有的互联网.针对DDOS攻击基于神经网络算法的防护,因为现有算法收敛性能不高,过滤DDOS攻击包的速度过慢,无法投入大规模商业使用.本文针对这个问题,提出借助SNORT入侵检测平台,利用捕捉的网络数据包进行数据规整化,利用贝叶斯模式对正常数据和异常数据进行初步分离,使得能减少冗余训练数据对神经网络的输入,之后利用改进的反向传播神经网络进行前期数据训练,使训练产生的数据对检测模型进行优化,并且自动生成防御规则.其优势在于:1)在linux系统上实现部分改进,使得现有包过滤效率增强,在攻击目标端生效之前可进行攻击拒绝;2)使用贝叶斯模型减少重复数据和不必要数据的输入,改进的神经网络算法使得训练收敛速度加快,方便规则的重新制定学习,以防新攻击.实验表明,本文方案在一定程度上提高了原有基于神经网络防护DDOS攻击的处理速度,也能够防护若干未知DDOS攻击,训练算法的收敛速度也得到进一步提升,并且该方案能在软件层面上提升自适应抗DDOS软件的性能.展开更多
Leaching process is the first step in zinc hydrometallurgy, which involves the complex chemical reactions for dissolving zinc bearing material in dilute sulfuric acid. Ensuring the safe running of the process is a key...Leaching process is the first step in zinc hydrometallurgy, which involves the complex chemical reactions for dissolving zinc bearing material in dilute sulfuric acid. Ensuring the safe running of the process is a key point in the operation. An expert fault diagnosis system for the leaching process was proposed, which has been implemented in a nonferrous metals smeltery. The system architecture and the diagnosis procedure were presented, and the rule models with the certainty factor were constructed based on the empirical knowledge, empirical data and statistical results on past fault countermeasures, and an expert reasoning strategy was proposed which employs the rule models and Beyes presentation and combines forward chaining and backward chaining. [展开更多
The Beyşehir-Hoyran Nappes,one of the tectonostratigraphic units of the Taurides,are thought to be originated from the Izmir-Ankara Ocean(northern branch of Neotethys).In this study,Late Paleozoic rock units from the ...The Beyşehir-Hoyran Nappes,one of the tectonostratigraphic units of the Taurides,are thought to be originated from the Izmir-Ankara Ocean(northern branch of Neotethys).In this study,Late Paleozoic rock units from the blocks of Beyşehir-Hoyran Nappes were studied in detail using foraminiferal assemblages in two different locations from the southwest of Karaman City(southern Turkey).In both places,blocks/slices and pebbles of various origins are embedded within a highly sheared matrix of Late Cretaceous Age,and the whole unit can be regarded as a sedimentary mélange.The ages of the blocks from the southwest of Karaman City range from the Late Serpukhovian(Late Mississippian)to Late Capitanian(Middle Permian)with some depositional breaks(e.g.,Bashkirian,Kasimovian).Combined with the previous data from the Mersin Mélange,which also include the remnants of the Beyşehir-Hoyran Nappes,our new findings suggest that a shallowing-upward sequence,characterized by a shallow water environment with foraminifera-bearing limestones,was deposited over the Tournaisian pelagic sequence in the Beyşehir-Hoyran Nappes till the Early Moscovian(Early Middle Pennsylvanian).This shallowing-upward sequence in the Beyşehir-Hoyran Nappes could be related to the Late Paleozoic Glaciation on the Gondwana supercontinent(Glacial Ⅱ),which resulted in a sea-level drop and deposition of platform carbonates during the Viséan–Early Moscovian(Middle Mississippian to Early Middle Pennsylvanian)time interval.The absence of the main part of the Middle-Upper Pennsylvanian deposits(continental phase during the Middle Moscovian–Middle Gzhelian)in the Beyşehir-Hoyran Nappes can be mainly attributed to the occurrence of a mantle plume and partially to the effect of Late Paleozoic Gondwanan Glaciation(Glacial Ⅲ).Progressive uplifting by the buoyant mantle plume material has resulted in rifting at the center of the basin where the Beyşehir-Hoyran Nappes have deposited.The rifting process led to tectonic destabilization of the platform in the basin,causing accumulation of the Upper Gzhelian(uppermost Pennsylvanian)detrital limestone with broken and abraded foraminiferal shells.Following this,deep basinal conditions prevailed during the Late Asselian–Kungurian(Early Permian),as revealed in the Mersin Mélange,where radiolarian cherts are associated with continental within-plate lavas of extreme incompatible trace element enrichment.Similar processes were responsible for the continual deposition of detrital limestones in the same basin until the end of Late Capitanian(Middle Permian).Based on all these,the uplifting process followed by rift-related volcanic rocks and detrital limestones can be interpreted as the opening of the Izmir-Ankara Ocean(northern Neotethys).展开更多
With the support by the National Natural Science Foundation of China,Prof.Zhong Xinhua’s laboratory at the School of Chemistry and Molecular Engineering,East China University of Science and Technology,reported the qu...With the support by the National Natural Science Foundation of China,Prof.Zhong Xinhua’s laboratory at the School of Chemistry and Molecular Engineering,East China University of Science and Technology,reported the quantum dot sensitized solar cells(QDSCs)with efficiency beyond 8%by recombination control,which was published in J Am Chem Soc(2015,137:5602—5609).展开更多
基金funded by the “Laboratoire de Recherche Ressources, Matériaux et Ecosystémes”, University of Carthage 7021 Zarzouna, Bizerte, Tunisia
文摘The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(< 200 ℃) compatible with boiling conditions. Such results open up perspectives for the development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.
文摘在网络安全问题中,一种分布式拒绝服务(Distributed deny of services)攻击严重威胁着现有的互联网.针对DDOS攻击基于神经网络算法的防护,因为现有算法收敛性能不高,过滤DDOS攻击包的速度过慢,无法投入大规模商业使用.本文针对这个问题,提出借助SNORT入侵检测平台,利用捕捉的网络数据包进行数据规整化,利用贝叶斯模式对正常数据和异常数据进行初步分离,使得能减少冗余训练数据对神经网络的输入,之后利用改进的反向传播神经网络进行前期数据训练,使训练产生的数据对检测模型进行优化,并且自动生成防御规则.其优势在于:1)在linux系统上实现部分改进,使得现有包过滤效率增强,在攻击目标端生效之前可进行攻击拒绝;2)使用贝叶斯模型减少重复数据和不必要数据的输入,改进的神经网络算法使得训练收敛速度加快,方便规则的重新制定学习,以防新攻击.实验表明,本文方案在一定程度上提高了原有基于神经网络防护DDOS攻击的处理速度,也能够防护若干未知DDOS攻击,训练算法的收敛速度也得到进一步提升,并且该方案能在软件层面上提升自适应抗DDOS软件的性能.
文摘Leaching process is the first step in zinc hydrometallurgy, which involves the complex chemical reactions for dissolving zinc bearing material in dilute sulfuric acid. Ensuring the safe running of the process is a key point in the operation. An expert fault diagnosis system for the leaching process was proposed, which has been implemented in a nonferrous metals smeltery. The system architecture and the diagnosis procedure were presented, and the rule models with the certainty factor were constructed based on the empirical knowledge, empirical data and statistical results on past fault countermeasures, and an expert reasoning strategy was proposed which employs the rule models and Beyes presentation and combines forward chaining and backward chaining. [
基金grateful to Hacettepe University,Scientific Research Project Department(No.FBA-2018-16915)for providing financial support to this research.
文摘The Beyşehir-Hoyran Nappes,one of the tectonostratigraphic units of the Taurides,are thought to be originated from the Izmir-Ankara Ocean(northern branch of Neotethys).In this study,Late Paleozoic rock units from the blocks of Beyşehir-Hoyran Nappes were studied in detail using foraminiferal assemblages in two different locations from the southwest of Karaman City(southern Turkey).In both places,blocks/slices and pebbles of various origins are embedded within a highly sheared matrix of Late Cretaceous Age,and the whole unit can be regarded as a sedimentary mélange.The ages of the blocks from the southwest of Karaman City range from the Late Serpukhovian(Late Mississippian)to Late Capitanian(Middle Permian)with some depositional breaks(e.g.,Bashkirian,Kasimovian).Combined with the previous data from the Mersin Mélange,which also include the remnants of the Beyşehir-Hoyran Nappes,our new findings suggest that a shallowing-upward sequence,characterized by a shallow water environment with foraminifera-bearing limestones,was deposited over the Tournaisian pelagic sequence in the Beyşehir-Hoyran Nappes till the Early Moscovian(Early Middle Pennsylvanian).This shallowing-upward sequence in the Beyşehir-Hoyran Nappes could be related to the Late Paleozoic Glaciation on the Gondwana supercontinent(Glacial Ⅱ),which resulted in a sea-level drop and deposition of platform carbonates during the Viséan–Early Moscovian(Middle Mississippian to Early Middle Pennsylvanian)time interval.The absence of the main part of the Middle-Upper Pennsylvanian deposits(continental phase during the Middle Moscovian–Middle Gzhelian)in the Beyşehir-Hoyran Nappes can be mainly attributed to the occurrence of a mantle plume and partially to the effect of Late Paleozoic Gondwanan Glaciation(Glacial Ⅲ).Progressive uplifting by the buoyant mantle plume material has resulted in rifting at the center of the basin where the Beyşehir-Hoyran Nappes have deposited.The rifting process led to tectonic destabilization of the platform in the basin,causing accumulation of the Upper Gzhelian(uppermost Pennsylvanian)detrital limestone with broken and abraded foraminiferal shells.Following this,deep basinal conditions prevailed during the Late Asselian–Kungurian(Early Permian),as revealed in the Mersin Mélange,where radiolarian cherts are associated with continental within-plate lavas of extreme incompatible trace element enrichment.Similar processes were responsible for the continual deposition of detrital limestones in the same basin until the end of Late Capitanian(Middle Permian).Based on all these,the uplifting process followed by rift-related volcanic rocks and detrital limestones can be interpreted as the opening of the Izmir-Ankara Ocean(northern Neotethys).
文摘With the support by the National Natural Science Foundation of China,Prof.Zhong Xinhua’s laboratory at the School of Chemistry and Molecular Engineering,East China University of Science and Technology,reported the quantum dot sensitized solar cells(QDSCs)with efficiency beyond 8%by recombination control,which was published in J Am Chem Soc(2015,137:5602—5609).
