检索结果-南通市图书馆

A Practical Intrusion Detection System for Internet of Vehicles

在线全文

学校读者我要写书评

暂无评论

China Communications 2016年第10期13卷 263-275页

作者： Wenliang Fu Xin Xin Ping guo Zhou Zhou School of Computer Science and Technology Beijing Institute of Technology National Engineering Laboratory for Information Security Technologies Institute of Information Engineering Chinese Academy of Sciences

Internet of Vehicles(henceforth called IoV) is a public network system and high-value target for intrusions that may cause efficiency issues, privacy leakages or even physical damage. Conventional intrusion detection methods are normally designed for the Internet infrastructures which cannot directly apply in the context of IoV. This work proposes an FPGA based intrusion detection method that can not only achieve real-time scanning performance but also be applied in vehicular environment. We evaluate our scheme on a Xilinx FPGA based platform. Experiments show that the proposed system can achieve a throughput of more than 39 Gbps on existing FPGA platform which is about 15% higher than state-of-the-art techniques,and the total power consumption for the prototype is about 7.5 w. Moreover, the processing latency of the prototype is about 4 us and is about one sixtieth part of the popular software IDS systems.

关键词： internet of vehicles intrusion detection VANET FPGA

Enhanced Cadmium Accumulation in Transgenic Tobacco Expressing the Phytochelatin Synthase Gene of Cynodon dactylon L

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2006年第8期48卷 928-937页

作者： Jiangchuan Li Jiangbo guo Wenzhong Xu Mi Ma Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany the Chinese Academy of Sciences Beijing 100093 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Bermudagrass （Cynodon dactylon L. cv. Goldensun） is highly resistant to and accumulates large amounts of cadmium （Cd）. A phytochelatin synthase （PCS） cDNA （CdPCS1） was isolated from this grass by rapid amplification of cDNA ends. The putative CdPCS1 protein shared a high homology with PCS from other plants, with 79% homology at the N-terminal and 47% homology at the C-terminah However, 16 Cys residues were found at the C-terminal of CdPCS1, and among these residues, three positions were different from other PCS proteins. Semiquantitative reverse transcription-polymerase chain reaction analysis showed that Cd stress induced CdPCS1 expression in both roots and leaves in Bermudagrass. We verified that CdPCS1 plays an important role in Cd tolerance in yeast cells by expressing the gene in ABDE1, a Cdsensitive mutant. CdPCS1 was then introduced into tobacco plants. The phytochelatin level in some transgenic tobacco lines increased 3.88-fold more than in wild type plants and Cd accumulation in these transgenic plants was enhanced 3.21-fold accordingly. The results suggested that CdPCS1 could be used as a gene element for phytoremediation in the future.

关键词： cadmium Cynodon dactylon phytochelatin phytochelatin synthase phytoremediation.

Changes in soil properties and erodibility of gully heads induced by vegetation restoration on the Loess Plateau, China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2018年第5期10卷 712-725页

作者： guo Mingming WANG Wenlong KANG Hongliang YANG Bo State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Northwest A&F University Yangling 712100 China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 China

Soil erosion on the Loess Plateau of China is effectively controlled due to the implementation of several ecological restoration projects that improve soil properties and reduce soil erodibility. However, few studies have examined the effects of vegetation restoration on soil properties and erodibility of gully head in the gully regions of the Loess Plateau. The objectives of this study were to quantify the effects of vegetation restoration on soil properties and erodibility in this region. Specifically, a control site in a slope cropland and 9 sites in 3 restored land-use types （5 sites in grassland, 3 in woodland and 1 in shrubland） in the Nanxiaohegou watershed of a typical gully region on the Loess Plateau were selected, and soil and root samples were collected to assess soil properties and root characteristics. Soil erodibility factor was calculated by the Erosion Productivity Impact Calculator method. Our results revealed that vegetation restoration increased soil sand content, soil saturated hydraulic conductivity, organic matter content and mean weight diameter of water-stable aggregate but decreased soil silt and clay contents and soil disintegration rate. A significant difference in soil erodibility was observed among different vegetation restoration patterns or land-use types. Compared with cropland, soil erodibility decreased in the restored lands by 3.99% to 21.43%. The restoration patterns of Cleistogenes caespitosa K. and Artemisia sacrorum L. in the grassland showed the lowest soil erodibility and can be considered as the optimal vegetation restoration pattern for improving soil anti-erodibility of the gully heads. Additionally, the negative linear change in soil erodibility for grassland with restoration time was faster than those of woodland and shrubland. Soil erodibility was significantly correlated with soil particle size distribution, soil disintegration rate, soil saturated hydraulic conductivity, water-stable aggregate stability, organic matt

关键词： soil erosion land use soil properties revegetation root characteristics headcut retreat Loess Plateau

Temporal Change of Runoff and Sediment Load and their Differential Response to Human Activities:A Case Study for a Well-vegetated Mountain Watershed of Southern China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2014年第1期11卷 73-85页

作者： ZHENG Ming-guo SUN Li-ying YAN Ming Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences & Natural Resources ResearchChinese Academic of Sciences

This study examined the temporal trends of runoff and sediment load and their differential response to human activities in the Lishui river,a tributary of the Yangtze river in southern *** long-term observation data at four gauging stations,generally involving two periods from 1954 to 1985 and from 2007 to 2011,were *** detected no significant temporal trend for both the annual runoff volume(Q) and the annual suspended Sediment Load(SL) over more than 30 years before *** flow duration curves and the Suspended Sediment Concentration(SSC) also hold constant before *** with the period before 1985,SL has decreased by about 80% though Q remains unchanged for the period after *** examination shows that the flow duration curves after 2007 have changed with a significant decrease in the high-flow component,which acts as a major cause for the decreasing *** addition,SSC has decreased by several times,which also contributes to the decrease in SL after *** decreases in high-flow discharges and in SSC can be linked with recent human activities,mainly including vegetation establishment and dam *** constant Q and the decreasing SL are also reported for the main stream of the Yangtze River and other major rivers in southern China,although they are orders of magnitude larger than our study area in drainage area *** present study highlights the importance of high-flow discharges on SL and suggests that the use of SL is more appropriate to reflect environmental change than Q.

关键词： Runoff Sediment load Reservoirs Environmental change Afforestation Lishui River

New development of longwall mining equipment based on automation and intelligent technology for thin seam coal

在线全文

学校读者我要写书评

暂无评论

Journal of Coal Science & Engineering(China) 2013年第1期19卷 97-103页

作者： guo-fa WANG China Coal Technology and Engineering Group Beijing 100013 China

The paper introduced complete sets of automatic equipment and technology used in thin seam coal face, and proposed the comprehensive mechanization and automation of safe and high efficiency mining models based on the thin seam drum shearer. The key technology of short length and high power thin seam drum shearer, and new type roof support with big extension ratio and plate canopy were introduced. The new research achievement on automatic control system of complete sets of equipment for the thin seam coal, which composed of electronic-hydraulic system, compact thin seam roof supports, high effective shearer with intelligent control system, and characterized by automatical follow-up and remote control technology, was described in this paper..

关键词： longwall mining thin coal seam complete sets of equipment automatic system intelligent system

Effect of Crystallographic Texture on Anisotropy of Yield Strength in X100 Pipeline Steel

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2013年第8期20卷 66-71页

作者： ZONG Cui ZHU guo-hui MAO Wei-min School of Materials Science and Engineering University of Science and Technology Beijing School of Materials Science and Engineering Anhui University of Technology

The anisotropy of microstructures and mechanical properties in commercial American Petroleum Institute （API） X100 pipeline steel was systematically investigated by experimental measurements. The experimental results show that anisotropy of yield strength could be observed considerably, which should be attributed to the crystallographic rex tures due to deformation and transformation of texture components. This is because the effect of the inhomogeneity of microstructure in different directions on the mechanical properties could be reasonably neglected based on the ex perimental investigation of grain size distribution. The effect of crystallographic texture on the anisotropy of yield strength was interpreted theoretically based on the relationship between yield strength and average orientation factor.

关键词： pipeline steel crystallographic texture yield strength anigotropy microstructure

A new integrated energy-saving scheme in green Fiber-Wireless(FiWi) access network

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2014年第6期57卷 74-88页

作者： LIU YeJun guo Lei ZHANG Lincong YANG JiangZi College of Information Science and Engineering Northeastern University

Energy savings in Internet have been regarded as a significant technical issue for academic and industrial ***,access network accounts for more than 70%of the total energy consumption of *** a promising access technique,Fiber-Wireless(FiWi)network not only enables the cost-effective broadband access,but also provides more opportunities for energy *** works mostly focused on the energy savings in the optical back-end of ***,they extended the Optical Network Unit(ONU)sleep mechanisms initially designed for Passive Optical Network(PON)to FiWi by combining with the wireless ***,most of these works left the energy savings in the wireless front-end *** fact,when one or more ONUs in the network is/are sleeping,many wireless components remain idle or underutilized which cause a lot of energy *** by this,we propose a new integrated Wireless-Optical Energy Savings(WOES)scheme for the comprehensive energy savings in *** WOES scheme consists of two interactive modules,Energy-Efficient ONU Management(EEOM)and Energy-Aware Topology Configuration(EATC).EEOM aims at the energy savings in the optical back-end by putting the low-load ONUs into sleep state.A pair of thresholds is introduced into EEOM to maintain the states of *** soon as ONUs states change,EATC will reconfigure the wireless topology by putting the idle Radio Interfaces(RIs)into standby state,thus minimizing the energy consumption of the wireless *** results show that the WOES scheme can reduce the energy consumption significantly with just a little performance degradation in network throughput and end-to-end delay.

关键词： Fiber-Wireless(FiWi) network energy savings ONU sleep radio interface standby

Viscosity, heat conductivity, and Prandtl number effects in the Rayleigh-Taylor Instability

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2016年第6期11卷 183-196页

作者： Feng Chen Ai-guo Xu Guang-Cai Zhang School of Aeronautics Shah Dong Jiaotong University Jinan 250357 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P.O. Box 8009-26 Beijing 100088 China Center for Applied Physics and Technology MOE Key center for High Energy Density Physics Simulations College of Engineering Peking University Beijing 100871 China

The two-dimensional Rayleigh-Taylor instability problem is simulated with a multiple-relaxation-time discrete Boltzmann model with a gravity term. Viscosity, heat conductivity, and Prandtl number effects are probed from macroscopic and nonequilibrium viewpoints. In the macro sense, both viscosity and heat conduction show a significant inhibitory effect in the reacceleration stage, which is mainly achieved by inhibiting the development of the Kelvin-Helmholtz instability. Before this, the Prandtl number effect is not sensitive. Viscosity, heat conductivity, and Prandtl number effects on nonequilibrium manifestations and the degree of correlation between the nonuniformity and the nonequilibrium strength in the complex flow are systematically investigated.

关键词： discrete Boltzmann model/method multiple-relaxation-time Rayleigh-Taylor instability nonequilibrium

Probing particle removal in brush scrubber cleaning with fluorescence technique

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2013年第12期56卷 2994-3000页

作者： HUANG YaTing LI Yang guo Dan MENG ChunLing School of Material and Mechanical Engineering Beijing Technology and Business University State Key Laboratory of Tribology Tsinghua University

Brush scrubber cleaning is widely used for post chemical mechanical polishing(CMP)cleaning in semiconductor *** this study,an experimental system based on fluorescence technique and particle-tracking velocimetry(PTV)technique was employed to characterize the particle removal displacement and velocity in the interface between a transparent copper film and a porous polyvinyl alcohol(PVA)brush during the cleaning *** different cleaning conditions including rotation speeds,loading pressure and cleaning agent were examined and the particle removal rate was *** and friction removal,hydrodynamic removal and mixed-type removal are the three types of particle *** with an arc trace and uniform velocity curves were removed by friction and elastic force which were related to the brush *** with a random trace and fluctuant velocity curves were removed by hydrodynamic force which was determined by the brush rotation *** increase of particle removal rate(PRR)with brush rotation speed is a logistic *** is easier to improve PRR by increasing the brush load or by adding surfactant than by increasing the brush rotation speed.

关键词： brush-scrub post CMP(chemical mechanical polishing) cleaning particle removal fluorescence technique