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Journal of Geoscience and Environment Protection 2024年第1期12卷 145-163页

作者： Hadji D. S. Kallon Lamin r. Mansaray Misbah Fida Pratap Sundar Shrestha Institute of Environmental management and Quality Control Njala University Njala Sierra Leone school of Water and Environment Chang’an University Xi’an China Quality Control Laboratory of Njala univ.r.ity Njala Sierra Leone Department of Surveys and Geo-Informatics School of Environmental Sciences Njala University Njala Sierra Leone

Artificial fishponds play a pivotal role in global aquaculture, serving as a source of livelihood and nourishment for many communities. Ensuring the sustained health and productivity of Fishes in these environments relies heavily on water quality management. This assessment was done to determine the water quality of ten artificial fishponds in the south-eastern part of Sierra Leone using twelve physicochemical factors (pH, BOD, EC, TDS, turbidity, COD, Fe2+, Mg2+, Ca2+, NH3./sub>, , and alkalinity) to find out the Water Quality Index (WQI) and spatial distribution of respective parameters. The assessment of artificial fishponds using WQI and Inverse Distant Weighting (IDW) integration represents a relatively underexplored area within the domain of environmental water.r.sources. The WQI was determined using the “Weighted Arithmetic Water Quality Index’’ method. The results of WQI in the study area range from 65.05 to 147.26. Several locations have water quality deemed unsuitable for consumption, while others range from good to very poor. It is essential to address and improve water quality in locations categorized as unsuitable for consumption and very poor to ensure safe and healthy water sources. It was also clear from the calculation that the smaller the mean concentration value of the pH as compared to the ideal value (7), the smaller the WQI value and the better the water quality. To keep the artificial fishpond water in good condition, mass domestic use should be controlled, and draining of surrounding organic matter should be stopped in ponds Bo_001, Kenema_001, and Kenema_002.

关键词： Physicochemical Parameters Water Quality Index WQI-“Weighted Arithmetic Index Method”

Generalized Cointegrated Time Series: representation and Estimation

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Systems Science and Systems Engineering 1998年第2期8卷 9-16页

作者： ZHANG Xibin and ZHANG Shiying school of management,Tianjin univ.r.ity,3.0072,P.r.{3.

Cointegration analysis is often of special interest in the analysis of nonstationary vector valued time series, especially for the vector with higher order integrated components. In this paper we present the representation theorem for a generalized cointegrated system, and formulate the generalized err.r. correction model(GECM). We also provide the modified EG two step procedure to estimate the parameters in a GECM. The paper extends some important results of cointegration into the analysis of generalized cointegration, and is of great importance in the analysis of nonstationary time series.

关键词： generalized err.r.correction model(GECM) representation theorem modified EG two-step procedure.

research on Methods of Ecological Security Assessment of the Middle and Lower.r.aches of Liaohe river Based on GIS

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Chinese Journal of Population,resources and Environment 2005年第4期3卷 20-25页

作者： Wang Geng 1,2 , Nie Baochi 3. Wang Lin 1 & Wu Wei 1 1. school of Environmental and Biological Science and technology, Dalian univ.r.ity of technology, Dalian 116024, china 2. Urban and Environmental school, Liaoning Normal univ.r.ity, Dalian 116029, china 3. Shenyang Buraue of Water.r.sources, Shenyang 110013. china. school of Environmental and Biological Science and technology Oalian University of Technology Oalian 116024 China Urban and Environmental school Uaoning Nonnal University Oalian 116029 China Shenyang Buraue of Water.r.sources Shenyang 110013 China

Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower.r.aches of the Liaohe river is taken as a study case. First, to work out pressure-state-response (P-S-r) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis.

关键词： the middle and lower.r.aches of the Liaohe river ecological security assessment indicators system GIS spatial differences

CHArACTErIZATION OF rEGENErATED CELLULOSE MEMBrANES HYDrOLYZED FrOM CELLULOSE ACETATE

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Chinese Journal of Polymer Science 2002年第4期20卷 369-375页

作者： Yun chen Xiao-peng Xiong Guang Yang Li-na Zhang Sen-lin Lei Hui Liang Electron Microscope Lab of Medical school, wuhan {3. wuhan 43.072, china College of Chemistry and Molecular Sciences, wuhan {3., wuhan 43.072, china wuhan univ Coll Chem & Mol Sci Wuhan 430072 Peoples R China wuhan univ Sch Med Electron Microscope Lab Wuhan 430072 Peoples R China

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infr.r.d spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

关键词： hydrolysis cellulose acetate thermal stability regenerated cellulose membrane pore size solvent-resistance SEM

Blockchain-based immunization against kleptographic attacks

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Science china(Information Sciences) 2024年第7期67卷 172-183页

作者： Changsong JIANG Chunxiang XU Jie chen Kefei chen school of Computer Science and Engineering University of Electronic Science and Technology of China Yangtze Delta region Institute (Huzhou) University of Electronic Science and Technology of China Department of Mathematics Hangzhou Normal University

Adversarial implementations of cryptographic primitives called kleptographic attacks cause the leakage of secret information. Subliminal channel attacks are one of the kleptographic attacks. In such attacks, backdoors are embedded in implementations of randomized algorithms to elaborately control randomness generation, such that the secrets will be leaked from biased outputs. To thwart subliminal channel attacks, double-splitting is a feasible solution, which splits the randomness generator of a randomized algorithm into two independent generators. In this paper, we instantiate double-splitting to propose a secure randomness generation algorithm dubbed SrG using two physically independent generators: ordinary and public randomness generators. Based on public blockchains, we construct the public randomness generator,which can be verified publicly. Hashes of a sufficient number of consecutive blocks that are newly confirmed on a blockchain are used to produce public randomness. In SrG, outputs from the two generators are taken as inputs of an immunization function. SrG accomplishes immunization against subliminal channel ***, we discuss the application strategies of SrG for symmetric and public-key encryption.

关键词： kleptographic attacks subliminal channel blockchain immunization randomized algorithm

STUDY OF PrIOrity ASSESSMENT OF MULTIPLE MECHANICAL PrODUCT PrOJECTS BASED ON AHP AND GrA

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STUDY OF PRIORITY ASSESSMENT OF MULTIPLE MECHANICAL PRODUCT ...

Pathways toward a pollution-free planet and challenges

International technology and Innovation Conference 2009

作者： chen Yan1 chen Hongming2 1 school of Logistics Engineering {3. univ.r.ity of technology {3. P.r.china 43.063.2 school of management {3. univ.r.ity of technology {3. P.r.china 43.070

Project-oriented mechanical manufacturing companies that make production per orders are limited with resources when getting several product projects. The decision makers have to made priority among projects to have ideal allocation and efficient use of resources. Based on the analysis of various factors affecting project priority, this paper designed a feasible and effective assessment index system in line with characteristics of mechanical product projects, incl. 4 categories with 11 indices. Then, the index weight values were determined with analytic hier.r.hy process, and a grey relational model on priority assessment of multiple mechanical product projects is proposed. It put forward a quantitative method of qualitative indices after the discussions of the index quantitative issues of the model. Finally, a case study justified that the combination use of analytic hier.r.hy process and grey relational analysis method could solve to some extent the issues that the subjective factor in priority assessment of multiple mechanical product projects was too much, as a quantitative reference for company decision-makers.

关键词： mechanical product multi-project management AHP GrA priority assessment

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Frontiers of Environmental Science & Engineering 2024年第6期18卷 3-8页

作者： Jiuhui Qu Jiaping chen school of Environment Tsinghua UniversityBeijing 100084China College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

The mission of“Establishment of Zero-Pollution Earth”defined by United Nations Environment Programme aims at creation of a clean,safe and prosperous home for all human *** is of rational choice from each individual to protect our environment and demonstrates our great ambition to achieve our *** key message given in this article is that,zero pollution does not mean no discharge of pollutants and instead it can be achievable through optimizing and controlling a sound balance between pollutants discharge and capacities of decontamination through treatment and natural environmental accumulation,which can be termed as“Principle of Equilibrium”between pollution and *** on this principle,we propose and illustrate several key factors and synergistic pathways toward a pollution-free planet:quantitative determination on purification and wastewater;source control through green measures;minimization of negative side-effects;precise management through digitalized systems;and keeping sound balance between pollutants and natural *** should be noted that we would face a series of difficulties and challenges in moving forward to“Zero-Pollution Earth”.We should further develop theories,principles and tools to achieve the balance between quantity of pollutants and decontamination *** should work together to break through the bottleneck limited by“Principle of equilibrium”to establish new environmental remediation systems leading to“Zero-Pollution Earth”.

关键词： Wastewater treatment resources recovery Greenhouse gases Energy Pollution-free

Study on Urban Agglomeration Integrative Innovation oriented by Productive service

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Study on Urban Agglomeration Integrative Innovation oriented...

regulating Anderson localization with structural defect disorder

The 2nd International Conference on Product Innovation management & The 3.d International Conference on Value Engineering

作者： Peng Wang cheng school of management,{3. univ.r.ity of technology,P.r.china,43.070

This research focuses on the integrative innovation of the productive service that is invisible product of transportation industry-urban agglomeration,This paper studies on the dot-line-section principle of urban agglomeration;on targets of logistics service mix innovation of productive service,transportation industrial vertical and horizontal integration, and urban agglomerate network integration;on computer and management combined integra- tive instruments:organizational tools,technology tools and platform tools which combine government,enter.r.ses and society at the same *** conclusion it summarizes the paths of building urban agglomeration innovation networks.

关键词： Productive service Transportation industry Urban agglomeration Integrate innovation

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Chinese Physics B 2024年第10期33卷 102-107页

作者： Mouyang cheng Haoxiang chen Ji chen school of Physics Peking UniversityBeijing 100871China Interdisciplinary Institute of Light-Element Quantum Materials and research Center for Light-Element Advanced Materials Peking UniversityBeijing 100871China Frontiers Science Center for Nano-Optoelectronics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

Localization due to disorder has been one of the most intriguing theoretical concepts that evolved in condensed matter ***,we expand the theory of localization by considering two types of disorders at the same time,namely,the original Anderson’s disorder and the structural defect disorder,which has been suggested to be a key component in recently discovered two-dimensional amorphous *** increasing the degree of both disorders could induce localization of wavefunction in real space,we find that a small degree of structural defect disorder can significantly enhance the *** the degree of structural defect disorder increases,localized states quickly appear within the extended phase to enter a broad crossover.r.gion with mixed *** establish two-dimensional diagrams for the wavefunction localization and conductivity to highlight the interplay between the two types of *** theoretical model provides a comprehensive understanding of localization in two-dimensional amorphous materials and highlights the promising tunability of their transport properties.

关键词： Anderson localization structural defect disorder electronic transport properties