检索结果-南通市图书馆

Assessment for soil loss by using a scheme of alterative sub-models based on the RUSLE in a Karst Basin of Southwest China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2017年第2期16卷 377-388页

作者： chen hao Takashi Oguchi WU Pan School of Political Science and Public Administration Huaqiao University Quanzhou 362021 P.R. China Department of Natural Environment Studies The University of Tokyo Kashiwa 277-8568 Japan Center for Spatial Information Science The University of Tokyo Kashiwa 277-8568 Japan College of Resources and Environmental Engineering Guizhou University Guiyang 550025 P.R. China

Accurate assessment of soil loss caused by rainfall is essential for natural and agricultural resources management. Soil erosion directly affects the environment and human sustainability. In this work, the empirical and contemporary model of revised universal soil loss equation （RUSLE） was applied for simulating the soil erosion rate in a karst catchment using remote sensing data and geographical information systems. A scheme of alterative sub-models was adopted to calculate the rainfall erosivity （R）, soil erodibility （K）, slope length and steepness （LS）, cover management （C） and conservation practice （P） factors in the geographic information system （GIS） environment. A map showing the potential of soil erosion rate was produced by the RUSLE and it indicated the severe soil erosion in the study area. Six classes of erosion rate are distinguished from the map： 1） minimal, 2） low, 3） medium, 4） high, 5） very high, and 6） extremely high. The RUSLE gave a mean annual erosion rate of 30.24 Mg ha-1 yr-1 from the 1980s to 2000s. The mean annual erosion rate obtained using RUSLE is consistent with the result of previous research based on in situ measurement from 1980 to 2009. The high performance of the RUSLE model indicates the reliability of the sub-models and possibility of applying the RUSLE on quantitative estimation. The result of the RUSLE model is sensitive to the slope steepness, slope length, vegetation factors and digital elevation model （DEM） resolution. The study suggests that attention should be given to the topographic factors and DEM resolution when applying the RUSLE on quantitative estimation of soil loss.

关键词： soil erosion RUSLE GIS Karst Basin

Investigation of MAS structure and intelligent^(+) information processing mechanism of hypersonic target detection and recognition system

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2020年第6期31卷 1105-1115页

作者： WU Xia LI Yan SUN Yongjian chen Alei chen Jianwen MA Jianchao chen hao Radar Sergeant School Air Force Early-Warning AcademyWuhan 430019China

The hypersonic target detection and recognition system is studied,on the basis of overall planning and design,a multi-agent system(MAS)structure and intelligent+information processing mechanism based on target detection and recognition are proposed,and the multi-agent operation process is analyzed and designed in *** the specific agents construction,the information fusion technology is introduced to defining the embedded agents and their interrelations in the system structure,and the intelligent processing ability of complex and uncertain problems is emphatically analyzed from the aspects of autonomy and *** aim is to optimize the information processing strategy of the hypersonic target detection and recognition system and improve the robustness and rapidity of the system.

关键词： hypersonic target detection recognition intelligent information fusion multi-agent system(MAS)

Approach for earth observation satellite real-time and playback data transmission scheduling

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2015年第5期26卷 982-992页

作者： hao chen Longmei Li Zhinong Zhong Jun Li School of Electronics Science and Engineering National University of Defense Technology

The scheduling of earth observation satellites(EOSs)data transmission is a complex combinatorial optimization problem. Current researches mainly deal with this problem on the assumption that the data transmission mode is fixed, either playback or real-time transmission. Considering the characteristic of the problem, a multi-satellite real-time and playback data transmission scheduling model is established and a novel algorithm based on quantum discrete particle swarm optimization(QDPSO)is proposed. Furthermore, we design the longest compatible transmission chain mutation operator to enhance the performance of the algorithm. Finally, some experiments are implemented to validate correctness and practicability of the proposed algorithm.

关键词： multi-satellite data transmission scheduling satellite data transmission mode decision particle swarm optimization mutation operator

Rainwater utilization and storm pollution control based on urban runoff characterization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第1期22卷 40-46页

作者： Mulan Zhang hao chen Jizhen Wang Gang Pan State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Institute of Environmental & Municipal Engineering North China University of Water Conservancy and Electric Power Zhengzhou 450011 China

The characteristics of urban runoffs and their impact on rainwater utilization and storm pollution control were investigated in three different functional areas of Zhengzhou City, China. The results showed that in the same rain event the pollutant loads （chemical oxygen demand （COD） and total suspended solids （TSS）） in the sampling areas were in the order of industrial area 〉 commercial area 〉 residential area, and within the same area the COD and TSS concentrations of road runoffs were higher than those of roof runoffs. The first flush effects in roof and road runoffs were observed, hence the initial rainwater should be treated separately to reduce rainwater utilization cost and control storm pollution. The initial roof rainfall of 2 mm in residential area, 5 mm in commercial area and 10 mm in industrial area, and the initial road rainfall of 4 mm in residential area and all the road rainfall in commercial and industrial areas should be collected and treated accordingly before direct discharge or utilization. Based on the strong correlation between COD and TSS （R2, 0.87-0.95） and the low biodegradation capacity （biochemical oxygen demand BOD5/COD 〈 0.3）, a sedimentation process and an effective filtration system composed of soil and slag were designed to treat the initial rainwater, which could remove over 90% of the pollutant loads. The above results may help to develop better rainwater utilization and pollution control strategies for cities with water shortages.

关键词： rainwater utilization water quality initial rainwater sedimentation and filtration

A new rotating black hole in quintessential dark energy and its thermodynamics

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2019年第11期62卷 63-68页

作者： Yue Wang chen-hao Wu Rui-Hong Yue Center for Gravitation and Cosmology College of Physical Science and Technology Yangzhou University

The spacetime metric for a rotating black hole in a quintessential field can take various forms owing to the ambiguity of the state equation for quintessential dark energy in rotating spacetime. Herein, to provide a more physical solution, the metric is determined by imposing the laws of thermodynamics of a black hole, which is typically valid in most systems. The new metric ensures the validity of the first and second laws of thermodynamics and can degenerate to the known non-rotating metric in the quintessential field. Moreover, we set an upper limit for the black hole rotation parameter, a, in our metric according to the weak energy condition(WEC).

关键词： rotating black holes in quintessential field thermodynamics weak energy condition

The entropy weighted non-uniform scanning algorithm for diffraction tomography

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2015年第6期58卷 182-194页

作者： SUN YuLi TAO JinXu chen hao LIU CongGui Department of Electronic Engineering and Information Science University of Science and Technology of China

This paper studies diffraction tomography based on Fourier diffraction projection theorem. By the observation of frequency domain projecting image, one can find that projection in frequency domain is not uniformly distributed when the spatial domain scanning angle is equispaced. This results in loss of *** analyze the conditions under which the information lost most. Then, we define the information entropy of each scanning and propose a non-uniform scanning algorithm to maximize the amount of information under conditions of a fixed number of sampling points and scanning angles. The algorithm has five different kinds of the weighting vectors based on different weighting programs. The simulation result supports our hypotheses and indicates that the algorithm proposed in this paper can obviously improve the reconstruction quality.

关键词： diffraction tomography Fourier diffraction projection theorem entropy total variation

Tumor-responsive copper-activated disulfiram for synergetic nanocatalytic tumor therapy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2021年第1期14卷 205-211页

作者： hao chen Xi Li Minfeng Huo Liying Wang Yu chen Wei chen Bailiang Wang School of Ophthalmology&Optometry Eye HospialWenzhou Medical UniversityWenzhou 325027China School of Life Sciences Shanghai UniversityShanghai 200444China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Shanghai Tenth People's Hospital Tongji University Schoo of MedicineShanghai 200072China

Exploring alternative biomedical use of traditional drugs in different disease models is highly important as it can reduce the cost of drug development and overcome several critical issues of traditional chemodrugs such as low chemotherapeutic efficiency,severe side effect,and drug ***(DSF),a clinically approved alcohol-aversion drug,was recently demonstrated tofeature tumor-growth suppression effect along with the co-administration of Cu^(2+)species,but direct Cu^(2+)administration mode might cause severe toxicity originating from low Cu^(2+)accumulation into the tumor and nonspecific Cu^(2+)distribution-induced *** on the intriguing drug-delivery performance of nanoscale metal-organic frameworks(MOFs),we herein construct HKUST nMOFs as the Cu^(2+)self-supplying nanocarriers for efficient delivery of the D SF *** mildly acidic condition of tumor microenvironment initially triggered the release of Cu ions from HKUST nMOFs,which further reacted with the encapsulated DSF toform toxic Cu(DDTC)2(activation)for tumor ***,during the Cu(DDTC)2 complexation,Cu^(+)species were formed concomitantly,triggering the intratumoral nanocatalytic therapy for the generation of reactive oxygen species to synergistically destroying the tumor cells/*** a result,synergetic tumor-responsive chemotherapy and nanocatalytic therapy are enabled by DSF@HKU ST nanodrugs,as demonstrated by the dominant anticancer efficacy with satisfied biocompatibility both in vitro and in *** present work offers a sophisticated strategy for tumor-responsive nontoxic-to-toxic therapeutic with high biocompatibility.

关键词： disulfiram metal-organic frameworks chemotherapy Fenton-like reaction tumor suppression

Adsorption behavior of condensed phosphate on aluminum hydroxide

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 Environmental Sciences 2007年第3期19卷 312-318页

作者： GUAN Xiao-hong chen Guang-hao SHANG Chii School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China Department of Civil Engineering Hong Kong University of Science and Technology Hong Kong China

Sodium pyrophosphate （pyro-P, Na4P2OT）, sodium tripolyphosphate （tripoly-P, Na3P3O10）, and sodium hexametaphosphate （meta-P, （NaPO3）6） were selected as the model compounds of condensed phosphate to investigate the adsorption behavior of condensed phosphate on aluminum hydroxide. The adsorption was found to be endothermic and divisible into two stages：（1） fast adsorption within 1 h; and （2） slow adsorption between 1 and 24 h. The modified Freundlich model simulated the fast adsorption stage well; the slow adsorption stage was described well by the first-order kinetics. The activation energies of pyro-P, tripoly-P, and meta-P adsorption on aluminum hydroxide were determined to be 20.2, 22.8 and 10.9 kJ/mol P adsorbed, respectively, in the fast adsorption stage and to be 66.3, 53.5 and 72.5 kJ/mol P adsorbed, respectively, in the slow adsorption stage. The adsorption increased the negative charge of the aluminum hydroxide surface. Transmission electron microscopy and energy dispersive X-ray analysis analyses provided evidence that the adsorption was not uniform on the surface and that the small crystals contributed more to the fast adsorption than the normal sites did. The results from X-ray fluorescence spectrometry and X-ray photoelectron spectroscopy tests also revealed the uneven adsorption of condensed phosphate as a function of the penetration depth. More condensed phosphates were adsorbed on the outer surface of aluminum hydroxide than in its inner parts.

关键词： activation energy aluminum hydroxide condensed phosphate eutrophication surface charge

Large power analysis of switched reluctance machine system for coal mine

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2009年第5期19卷 657-659页

作者： chen hao PAVLITOV Constantin School of Chemical Engineering and Technology China University of Mining ＆ Technology Xuzhou Jiangsu 221116 China Department of Automation of Electrical Drives Faculty of Automation Technical University of Sofia Sofia Bulgaria

The conventional structures in the Switched Reluctance machines are introduced, such as three-phase 12/8 structure Switched Reluctance machine, three-phase 6/4 structure Switched Reluctance machine, four-phase 16/12 structure Switched Reluctance machine, and four-phase 8/6 structure Switched Reluctance machine. Three-phase 12/8 structure Switched Reluctance machine is the best choice for the large power Switched Reluctance machine system in coal mines. The asymmetric bridge power converter main circuit and the bifilar winding power converter main circuit are also introduced. Three-phase asymmetric bridge power converter main circuit is the best choice for the large power Switched Reluctance machine system in coal mines. The magnetic paths of the designed large power motor are given with one phase excitation and double phases excitation. The phase current waveforms are also given.

关键词： switched reluctance large power simulation