检索结果-南通市图书馆

Basical characteristics of fluid geologic process of interlayer oxidation zone sandstone-typeuranium deposit

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2007年第Z2期50卷 185-194页

作者： wu BoLin LIU ChiYang WANG JianQiang State Key Laboratory of Continental Dynamics(Northwest University) Xi'an 710069 China State Key Laboratory of Continental Dynamics(Northwest University) Xi'an 710069 China State Key Laboratory of Continental Dynamics(Northwest University) Xi'an 710069 China

This paper reveals the physicochemical properties such as component, formulation, genesis, tem- perature, pH, Eh, salinity and pressure of all main alteration fluid of interlayer oxidation zone sand- stone-type uranium deposits after studying the geologic process and geochemistry of internal typical sandstone-type uranium deposits such as Shihongtan deposit in the Turpan-Hami basin, 512 deposit in the Yili basin, Dongsheng deposit in the Ordos basin. The composition of fluid can be divided into two parts based on the analysis of inclusion: one can be affirmed as atmospheric water with ordinary temperature epigenesist according to the character of hydrogen and oxygen isotope of inclusion, the other is natural gas containing gaseous hydrocarbon like CH4, and CO2 as well as a little H2S, CO, H2, N2 and so on, it always contains a small quantity of hydrocarbon liquid in petroliferous basins. The fluid property of oxidation alteration zone is always oxidation alkaline, and neutrality or weak acid-weak alkaline and reducibility during the metallizing process, but at secondary reduction or deoxidization zone it becomes strong reduction alkaline. Oxygenic groundwater in the fluid is the activate and mig- ratory medium of uranium element, but the gaseous hydrocarbon like CH4 as well as H2, H2S, CO from natural gas is the important sedimentary reducer of uranium mineral; the transformation of pH,Eh in fluid environment is the main reason for the formation of uranium metallization.

关键词： fluid, interlayer oxidation zone, uranium deposit, inclusion, isotope

Evolution of misfit dislocation network and tensile properties in Ni-based superalloys:a molecular dynamics simulation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2012年第3期55卷 419-427页

作者： wu WenPing GUO YaFang WANG YueSheng Department of Engineering Mechanics Wuhan UniversityWuhan 430072China Department of Mechanical Engineering University of WuppertalWuppertal 42097Germany Institute of Engineering Mechanics Beijing Jiaotong UniversityBeijing 100044China

The structural evolution of dislocation network is closely related to y' rafting and tensile properties. In this work, the effects of strain rate and temperature on the structural evolution of interface dislocation network in Ni-based superalloys are studied by molecular dynamics simulations. The correlation between the evolution of dislocation network and tensile properties is also explored. The results indicate that the dislocation network shows different degrees of deformation and damage at various strain rates and temperatures. The ),' rafting depends on the damage structure of dislocation network at various strain rates and tem- peratures. Moreover, the tensile properties of interface in Ni-based superalloys are closely related to the evolution of disloca- tion network and dislocation motion mechanisms.

关键词： Ni-based superalloys tensile properties dislocation network rafting molecular dynamics simulation

Coherent Phase-Coded Pulse Train with Doppler Cascade-Processing for Detection of Aircraft Target in a HF Radar

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 1999年第3期10卷 50-56页

作者： Shen, Yiying Liu, Yongtan wu, Aiguang Harbin Inst of Technology Harbin China

The effect of range-Doppler coupling caused by aircraft moving at very high speed makes trouble on selection of waveform parameters by using frequency-modulated interrupted continuous wave (FMICW) or frequency-coded pulse (FCP). It also limits the increasing of coherent integration time. In this paper, application of coherent phase-coded pulse train (CPCPT) solves range-Doppler coupling well. Relevant processing of CPCPT consists of three parts: Doppler preprocessing, pulse compression, and Doppler post-processing. The velocity information obtained by Doppler preprocessing is used for better pulse compression and range tracking. Doppler post-processing with range tracking could make longer coherent accumulation for better detection of target and higher velocity resolution. Finally, examples of data simulation are given to demonstrate the achievements mentioned above.

关键词： Computer simulation Doppler effect Frequency modulation Problem solving Waveform analysis

Compositional and Structural Difference of Fulvic Acid from Black Soil Applied with Different Organic Materials: Assessment After Three Years

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2013年第10期12卷 1865-1871页

作者： LI Jian-ming wu Jing-gui College of Resource and Environment Science Jilin Agricultural University

Knowledge of different effects of various organic materials on soil humic substance is important for both environmental safety and sustainable agriculture.A pot experiment was conducted at Jilin Agricultural University,Jilin Province in northeast China to discover the influence of herb residue,animal excrement,woody residue,animal remnant on fulvic acid（FA） composition and structure using differential thermal analysis-thermogravimetric（DTA-TG）,fourier transform infrared spectroscopy（FTIR） and elemental ***-TG showed the range of peak temperature in the first exothermic reaction increased following the trend： CK〉herb residue〉animal excrement〉woody residue=animal remnant,and the most weight loss was observed in animal ***,the second exothermic reaction of CK-and animal excrement-FA was presented as double peaks,the order of weight loss in that area was animal remnant〉CK〉woody residue〉animal excrement〉herb *** to FTIR,herb residue displayed higher adsorption intensity at 2 950,1 420,1 240 and 1 030 cm-1,animal excrement was in *** the same time,herb residue-and animal excrement-FA had an absorption peak at 1 720 cm-1,while other organic materials didn＇t have this *** elemental analysis showed,FA isolated from various treatments was significantly *** was clearly shown from our results that FA composition and structure in amended soils may be affected in different ways and at various extents on dependence of the nature and origin of amendment.

关键词： different organic materials fulvic acid DTA-TG FTIR elemental analysis

Contrastive Consistency and Attentive Complementarity for Deep Multi-View Subspace Clustering

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 143-160页

作者： Jiao Wang Bin wu Hongying Zhang School of Information Engineering Southwest University of Science and TechnologyMianyang621010China

Deep multi-view subspace clustering (DMVSC) based on self-expression has attracted increasing attention dueto its outstanding performance and nonlinear application. However, most existing methods neglect that viewprivatemeaningless information or noise may interfere with the learning of self-expression, which may lead to thedegeneration of clustering performance. In this paper, we propose a novel framework of Contrastive Consistencyand Attentive Complementarity (CCAC) for DMVsSC. CCAC aligns all the self-expressions of multiple viewsand fuses them based on their discrimination, so that it can effectively explore consistent and complementaryinformation for achieving precise clustering. Specifically, the view-specific self-expression is learned by a selfexpressionlayer embedded into the auto-encoder network for each view. To guarantee consistency across views andreduce the effect of view-private information or noise, we align all the view-specific self-expressions by contrastivelearning. The aligned self-expressions are assigned adaptive weights by channel attention mechanism according totheir discrimination. Then they are fused by convolution kernel to obtain consensus self-expression withmaximumcomplementarity ofmultiple views. Extensive experimental results on four benchmark datasets and one large-scaledataset of the CCAC method outperformother state-of-the-artmethods, demonstrating its clustering effectiveness.

关键词： Deep multi-view subspace clustering contrastive learning adaptive fusion self-expression learning

Energy-shaping for Hamiltonian control systems with time delay

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2013年第3期11卷 436-441页

作者： Liangcheng CAI Yong HE Min wu School of Information Science and Engineering Central South University Hunan Engineering Laboratory for Advanced Control and Intelligent Automation

This paper investigates the asymptotical stabilization of Hamiltonian control systems with time delay. First, Hamiltonian control systems with time delay are proposed. Second, a two-to-one （TTO） principle is introduced that two different Hamiltonian functions are simultaneously energy-shaping by one desired energy function. Third, a novel matching equation is built via the TTO principle for the Hamiltonian control systems with time delay, which generates an effective control law for the Hamiltonian control systems with time delay. Finally, a numerical example shows the effectiveness of proposed method.

关键词： Time delay Hamiltonian control systems Energy-shaping

Tides and Turbulent Mixing in the North of Taiwan Island

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2019年第3期36卷 313-325,341页

作者： Xiangzhou SONG Dexing wu Xiaohui XIE State Oceanic Administration Ministry of Nat-ural Resources Physical Oceanography Laboratory Ocean University of China National Marine Environmental Forecasting Center State Oceanic Administration Horn Point Laboratory University of Maryland Center for Environmental Science

Microstructure and hydrological profiles were collected along two cross-shelf sections from the deep slope to the shallow water in the north of Taiwan Island in the summer of *** the tidal currents on the shelf were dominated by the barotropic tide with the current ellipse stretched across the shelf,significant internal tides were observed on the *** depth-mean turbulent kinetic energy(TKE)dissipation rate on the shelf was 10^-6W kg^-1,corresponding to a diapycnal diffusivity of 10^-2 m^2s^-*** depth-mean TKE dissipation rate on the slope was 1×10^-7 Wkg^-1,with diapycnal diffusivity of 3×10^-4m^2s^-*** shear instability associated with internal tides largely contributed to the TKE dissipation rate on the slope from the surface to 150 m,while the enhanced turbulence on the shelf was dominated by tidal or residual current dissipations caused by friction in the thick bottom boundary layer(BBL).In the BBL,the Ekman currents associated with the northeastward Taiwan Warm Current were identified,showing a near-bottom velocity spiral,which agreed well with the analytical bottom Ekman solution.

关键词： microstructure observations turbulent mixing internal tides bottom boundary layer bottom Ekman spiral

Resource Allocation for URLLC with Parameter Generation Network

在线全文

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2023年第4期8卷 319-328页

作者： Jiajun wu Chengjian Sun Chenyang Yang School of Electronics and Information Engineering Beihang UniversityBejing 100191China

Deep learning enables real-time resource allocation for ultra-reliable and low-latency communications(URLLC),one of the major use cases in the next-generation cellular *** the high training complexity and weak generalization ability of neural networks impede the practical use of the learning-based methods in dynamic wireless *** overcome these obstacles,we propose a parameter generation network(PGN)to efficiently learn bandwidth and power allocation policies in *** PGN consists of two types of fully-connected neural networks(FNNs).One is a policy network,which is used to learn a resource allocation policy or a Lagrangian multiplier *** other type of FNNs are hypernetworks,which are designed to learn the weight matrices and bias vectors of the policy *** the hypernetworks require *** the well-trained hypernetworks,the policy network is generated through forward propagation in the test *** introducing a simple data processing,the hypernetworks can well learn the weight matrices and bias vectors by inputting their indices,resulting in low training *** results demonstrate that the learned bandwidth and power allocation policies by the PGNs perform very close to a numerical ***,the PGNs can be well generalized to the number of users and wireless channels,and are with significantly lower memory costs,fewer training samples,and shorter training time than the traditional learning-based methods.

关键词： URLLC resource allocation hypernetworks deep learning

MESO-based Robustness Voltage Sliding Mode Control for AC Islanded Microgrid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2020年第2期6卷 83-93页

作者： Hao Pan Qingfang Teng Dangdang wu School of Electrical Engineering and Automation Lanzhou Jiaotong UniversityLanzhou 730070China

A new modified extended state observer(MESO)-based robustness voltage sliding mode control(SMC)strategy is proposed for an AC islanded microgrid under system uncertainties including system parameter and load ***,the disturbance effect on the system is regarded as a lumped uncertainty,and a state space model of the uncertain islanded microgrid system is ***,a modified extended state observer is designed to estimate external disturbances and internal ***,considering the lumped uncertainty,a sliding mode controller with a multi-power reaching law is proposed to enable the output voltage of the system to track its reference voltage rapidly and accurately,and to enhance the robustness of the *** simulation results confirm that the proposed robustness voltage control strategy can perform satisfactory voltage control and demonstrate a strong capability to reject parameter and load variation.

关键词： Islanded microgrid modified extended state observer multi-power reaching law system uncertainties robustness voltage sliding mode control