Industrial Control Systems(ICSs)are the lifeline of a country.Therefore,the anomaly detection of ICS traffic is an important endeavor.This paper proposes a model based on a deep residual Convolution Neural Network(CNN...Industrial Control Systems(ICSs)are the lifeline of a country.Therefore,the anomaly detection of ICS traffic is an important endeavor.This paper proposes a model based on a deep residual Convolution Neural Network(CNN)to prevent gradient explosion or gradient disappearance and guarantee accuracy.The developed methodology addresses two limitations:most traditional machine learning methods can only detect known network attacks and deep learning algorithms require a long time to train.The utilization of transfer learning under the modification of the existing residual CNN structure guarantees the detection of unknown attacks.One-dimensional ICS flow data are converted into two-dimensional grayscale images to take full advantage of the features of CNN.Results show that the proposed method achieves a high score and solves the time problem associated with deep learning model training.The model can give reliable predictions for unknown or differently distributed abnormal data through short-term training.Thus,the proposed model ensures the safety of ICSs and verifies the feasibility of transfer learning for ICS anomaly detection.展开更多
Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise...Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise technique the Holocene corals from the South China Sea were dated. Comparison between this method and α-spectrometry was made. The results show that a thriving period of corals in the South China Sea appeared at 6 800—5 800 a BP, during which the paleosea level was the higher than at present in the Holecene.展开更多
Semiconductor exciton–polaritons in planar microcavities form coherent two-dimensional condensates in non-equilibrium.However,the coupling of multiple lower-dimensional polariton quantum systems,which are critical fo...Semiconductor exciton–polaritons in planar microcavities form coherent two-dimensional condensates in non-equilibrium.However,the coupling of multiple lower-dimensional polariton quantum systems,which are critical for polaritonic quantum device applications and novel cavity-lattice physics,has been limited in conventional cavity structures.Here,we demonstrate full non-destructive confinement of polaritons using a hybrid cavity composed of a single-layer subwavelength grating mirror and a distributed Bragg reflector.Single-mode polariton lasing was observed at a chosen polarization.The incorporation of a designable slab mirror in a conventional vertical cavity,when operating in the strong-coupling regime,enables the confinement,control and coupling of polariton gasses in a scalable fashion.This approach may open the door to experimental implementations of polariton-based quantum photonic devices and coupled cavity quantum electrodynamic systems.展开更多
The 187Os/ 188Os ratios of spinel lherzolite xenoliths from Panshishan determined with N-TIMS are lower than that of the primitive mantle, which shows depleted mantle characteristics. Their positive correlation with A...The 187Os/ 188Os ratios of spinel lherzolite xenoliths from Panshishan determined with N-TIMS are lower than that of the primitive mantle, which shows depleted mantle characteristics. Their positive correlation with Al-2O-3/MgO suggests that the geochemical behavior of trace elements Re and Os is similar to that of Al-2O-3 and MgO respectively during the magmatic evolution and Re-Os isotopic system is largely immune to mantle metasomatism. A model age of 2 8-3 4 Ga obtained by 187Os/ 188Os-Al-2O-3/MgO correlation might represent the homogeneous age of the mantle lithosphere beneath the area.展开更多
The osmium isotopic ratio of 187Os/ 188Os ranging from 0.126 to 0.127 for the primitive upper mantle (PUM) is obtained according to the correlation between 187Os/ 188Os and Al 2O 3 of mantle-derived xenoliths and orog...The osmium isotopic ratio of 187Os/ 188Os ranging from 0.126 to 0.127 for the primitive upper mantle (PUM) is obtained according to the correlation between 187Os/ 188Os and Al 2O 3 of mantle-derived xenoliths and orogenic peridotites, which consists with Allegre and Luck’s ALM value and similar to Yin’s nuggets uniform reservoir (NUR) value. It shows that the Os isotope ratio is lower than enstatite or ondinary chondrites, similar to carbonaceous chondrites (CV3).展开更多
基金supported in part by 2018 industrial Internet innovation and development project“Construction of Industrial Internet Security Standard System and Test and Verification Environment”in part by the National Industrial Internet Security Public Service Platform+2 种基金in part by the Fundamental Research Funds for the Central Universities(Nos.FRF-BD-19-012A and FRFTP-19-005A3)in part by the National Natural Science Foundation of China(Nos.81961138010,U1736117,and U1836106)in part by the Technological Innovation Foundation of Shunde Graduate School,University of Science and Technology Beijing(No.BK19BF006)。
文摘Industrial Control Systems(ICSs)are the lifeline of a country.Therefore,the anomaly detection of ICS traffic is an important endeavor.This paper proposes a model based on a deep residual Convolution Neural Network(CNN)to prevent gradient explosion or gradient disappearance and guarantee accuracy.The developed methodology addresses two limitations:most traditional machine learning methods can only detect known network attacks and deep learning algorithms require a long time to train.The utilization of transfer learning under the modification of the existing residual CNN structure guarantees the detection of unknown attacks.One-dimensional ICS flow data are converted into two-dimensional grayscale images to take full advantage of the features of CNN.Results show that the proposed method achieves a high score and solves the time problem associated with deep learning model training.The model can give reliable predictions for unknown or differently distributed abnormal data through short-term training.Thus,the proposed model ensures the safety of ICSs and verifies the feasibility of transfer learning for ICS anomaly detection.
文摘Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise technique the Holocene corals from the South China Sea were dated. Comparison between this method and α-spectrometry was made. The results show that a thriving period of corals in the South China Sea appeared at 6 800—5 800 a BP, during which the paleosea level was the higher than at present in the Holecene.
基金BZ,ZW and HD acknowledge support from the National Science Foundation under Awards DMR 1150593 for measurements and OISE 1132725 for travel expenses and the Air Force Office of Scientific Research under Award FA9550-12-1-0256 for device fabrication and characterization.CS,SB,MK and SH acknowledge support from the State of Bavaria,Germany.Fabrication of the SWG was performed at the Lurie Nanofabrication Facility,which is part of the National Science Foundation NNIN network.
文摘Semiconductor exciton–polaritons in planar microcavities form coherent two-dimensional condensates in non-equilibrium.However,the coupling of multiple lower-dimensional polariton quantum systems,which are critical for polaritonic quantum device applications and novel cavity-lattice physics,has been limited in conventional cavity structures.Here,we demonstrate full non-destructive confinement of polaritons using a hybrid cavity composed of a single-layer subwavelength grating mirror and a distributed Bragg reflector.Single-mode polariton lasing was observed at a chosen polarization.The incorporation of a designable slab mirror in a conventional vertical cavity,when operating in the strong-coupling regime,enables the confinement,control and coupling of polariton gasses in a scalable fashion.This approach may open the door to experimental implementations of polariton-based quantum photonic devices and coupled cavity quantum electrodynamic systems.
文摘The 187Os/ 188Os ratios of spinel lherzolite xenoliths from Panshishan determined with N-TIMS are lower than that of the primitive mantle, which shows depleted mantle characteristics. Their positive correlation with Al-2O-3/MgO suggests that the geochemical behavior of trace elements Re and Os is similar to that of Al-2O-3 and MgO respectively during the magmatic evolution and Re-Os isotopic system is largely immune to mantle metasomatism. A model age of 2 8-3 4 Ga obtained by 187Os/ 188Os-Al-2O-3/MgO correlation might represent the homogeneous age of the mantle lithosphere beneath the area.
文摘The osmium isotopic ratio of 187Os/ 188Os ranging from 0.126 to 0.127 for the primitive upper mantle (PUM) is obtained according to the correlation between 187Os/ 188Os and Al 2O 3 of mantle-derived xenoliths and orogenic peridotites, which consists with Allegre and Luck’s ALM value and similar to Yin’s nuggets uniform reservoir (NUR) value. It shows that the Os isotope ratio is lower than enstatite or ondinary chondrites, similar to carbonaceous chondrites (CV3).
