期刊文献+
共找到81,954篇文章
< 1 2 250 >
每页显示 20 50 100
Oxidation Kinetics of Aluminum Powders in a Gas Fluidized Bed Reactor in the Potential Application of Surge Arresting Materials
1
作者 Hong Shih 《Materials Sciences and Applications》 2019年第3期253-292,共40页
In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arre... In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general. 展开更多
关键词 Aluminum Spherical Power GAS FLUIDIZATION Bed Oxidation Mechanism Oxide Growth Rate Gibbs Free Energy Ellingham Diagram Mathematical Modeling Dynamic System Plasma DIFFUSION DIFFUSION Coefficient Crystallographic Defect Vacancy Pressure Temperature Flow Laplace Transform Equation Boundary Condition Ficks Second Law Software Experimental Theoretical SURGE ARRESTING MATERIALS analytical Solution
下载PDF
The assessment of time dependent flow of Williamson fluid with radiative blood flow against a wedge 被引量:1
2
作者 K.Subbarayudu S.Suneetha P.Bala Anki Reddy 《Propulsion and Power Research》 SCIE 2020年第1期87-99,共13页
The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a we... The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a wedge with radiation.The governing equations are transformed into ordinary differential equations by using similarity variables.The analytical solutions of the transformed governing equations are obtained by using the RK 4th order method along with shooting technique solver.The effects of various physical parameters such as Hartmann number,local Weissenberg number,radiation parameter,unsteadiness parameter,Prandtl number,Lewis number,Brownian diffusion,thermophoresis,wedge angle parameter,moving wedge parameter,on velocity,temperature,concentration,skin friction,heat transfer rate and mass transfer rate have been discussed in detail.The velocity and temperature profile deprives for larger We and an opposite trend is observed for concentration.The radiation parameter is propositional to temperature and a counter behaviour is observed for Pr. 展开更多
关键词 The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic WILLIAMSON fluid model. Assuming the flow IS unsteady and blood IS treated as WILLIAMSON fluid over a WEDGE with radiation. The governing EQUATIONS are transformed into ordinary differential EQUATIONS by using similarity variables. The analytical solutions of the transformed governing EQUATIONS are obtained by using the RK 4th order method along with shooting technique solver. The effects of various physical parameters such as Hartmann NUMBER local Weissenberg NUMBER radiation PARAMETER unsteadiness PARAMETER Prandtl NUMBER Lewis NUMBER Brownian diffusion thermophoresis WEDGE angle PARAMETER moving WEDGE PARAMETER on velocity temperature concentration skin friction heat transfer rate and mass transfer rate have been discussed in detail. The velocity and temperature profile deprives for larger We and an opposite trend IS observed for concentration. The radiation PARAMETER IS propositional to temperature and a counter behaviour IS observed for Pr.
原文传递
Analytical characterization and structure elucidation of metabolites from Aspergillus ochraceus MP2 fungi 被引量:1
3
作者 Meenupriya J Thangaraj M 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第5期376-380,共5页
Objective:To isolate and characterize the bioactive secondary metabolites from Aspergillus ochraceus(A.ochraceus)MP2 fungi.Methods:The anti bacterial activity of marine sponge derived fungi A.ochraceus MP2 was thoroug... Objective:To isolate and characterize the bioactive secondary metabolites from Aspergillus ochraceus(A.ochraceus)MP2 fungi.Methods:The anti bacterial activity of marine sponge derived fungi A.ochraceus MP2 was thoroughly investigated against antagonistic human pathogens.The optimum inhibitory concentration of the fungi in the elite solvent was also determined.The promising extracts that showed good antimicrobial activity were subjected to further analytical separation to get individual distinct metabolites and the eluants were further identified by GC MS instrumental analysis.The molecular characterization of the elite fungal strains were done by isolating their genomic DNA and amplify the internal transcribed spacer(US)region of 5.8s rRNA using specific ITS primer.The novelty of the strain was proved by homology search tools and elite sequences was submitted to GENBANK.Results:Three bioactive compounds were characterized to reveal their identity,chemical formula and structure.The first elutant was identified asα-Campholene aldehyde with chemical fonnula C_(10)H_(16)O and molecular weight 152 Da.The second elutant was identified as Lucenin-2 and chemical fonnula C_(27)H_(30)O_(16)and molecular weight 610Da.The third elutant was identified as 6-Ethyloct-3-yl-2-ethylhexyl ester with Chemical fonnula C_(26)H_(42)O_4 with molecular weight 418 Da.Conclusions:The isolated compounds showed significant antimicrobial activity against potential human pathogens.Microbial secondary metabolites represent a large source of compounds endowed with ingenious structures and potent biological activities. 展开更多
关键词 Marine sponge derived FUNGI Aspergillus ochraceus Bioactive METABOLITES Antibacterial ACTIVITY analytical CHARACTERIZATION FUNGI Apergillus Bioactive secondary metabolite Antagonistic human pathogen Antimicrobial ACTIVITY Bioactive compounds
下载PDF
Validation of a Questionnaire to Diagnose the Baumann Skin Type in All Ethnicities and in Various Geographic Locations
4
作者 Leslie Baumann 《Journal of Cosmetics, Dermatological Sciences and Applications》 2016年第1期34-40,共7页
The Baumann Skin Typing System diagnoses patients as having one of 16 skin types based on their answers to a validated questionnaire [i] known as the Baumann Skin Type Indicator [ii]. The BSTI questionnaire has been t... The Baumann Skin Typing System diagnoses patients as having one of 16 skin types based on their answers to a validated questionnaire [i] known as the Baumann Skin Type Indicator [ii]. The BSTI questionnaire has been tested over the last decade on over 200,000 people of various ages and ethnicities in different geographic locations around the world. In this study, data were collected from 52,862 patients to compare skin type prevalence between those who presented to doctor’s offices and those who took the quiz without supervision online. The most common skin types varied only slightly between patients that took the quiz online and those that completed the questionnaire in their doctor’s office. This indicates that the prevalence of skin types seen in the doctor’s office is similar to that in the general population and that supervision is not necessary to get an accurate result on the BSTI. [iii] In addition, comparison of data gathered in China, Korea, and the US did not show a significant difference in skin type prevalence between Asian and Caucasian skin types. [iv] This study demonstrates that the English version of the BSTI is valid for English speaking patients online, and in doctors’ offices in the US, China and Korea. 展开更多
关键词 Skin Type Regimen COSMECEUTICAL Skin Care Oily Dry Sensitive Pigmented Wrinkled Photoaged MELASMA Pre-Operative Post-Operative Acne ROSACEA Contact Dermatitis Antioxidants Retinoids Baumann Skin Type BSTI Skin IQ Skin Type Solutions Systems-Based Approach Standardized methodology Validated VALIDATION Scientific Ethnicity Asian Hispanic Caucasian QUESTIONNAIRE Diagnostic DIAGNOSE Prescribe Educate Outcomes Compliance
下载PDF
GIS Based Landslide Susceptibility Mapping with Application of Analytical Hierarchy Process in District Ghizer, Gilgit Baltistan Pakistan 被引量:3
5
作者 Irum Rahim Syeda Maria Ali Maria Aslam 《Journal of Geoscience and Environment Protection》 2018年第2期34-49,共16页
District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of na... District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of natural hazards, the present study was designed to generate landslide susceptibility map based on twelve causative factors viz., slope, aspect, elevation, drainage network, Stream Power Index (SPI), Topographic Wetness Index (TWI), lithological units, fault lines, rainfall, road network, land cover and soil texture. Soil texture was determined by particle size analysis and data for other factors were acquired from freely available sources. Analytical Hierarchy Process (AHP) was employed to identify major landslide causative factors in the district Ghizer. Further, a temporal assessment from 1999 till 2015 was generated to assess the impact of land cover change on landslides. It indicated that the barren soil/ exposed rocks and glaciers have reduced while the vegetation and water classes have shown increment. The total area that lies in moderate to very high landslide susceptible zones was 74.38%, while slope is the main landslide causative factor in the district Ghizer. Validation of the susceptibility map showed 88.1% of the landslides in the study area had occurred in the moderate to very high susceptible zones. 展开更多
关键词 LANDSLIDE SUSCEPTIBILITY Mapping (LSM) analytical HIERARCHY Process (AHP) GEOGRAPHIC Information System (GIS) Weighted Linear Combination (WLC) Remote Sensing (RS)
下载PDF
Exploration of Ideological and Political Materials for the Course of Inorganic and Analytical Chemistry for Environmental and Ecological Engineering Major
6
作者 Lihua XIE Siqian JIAO +4 位作者 Pengqiang YAO Weishuang TONG Yanjiao LI Zhe WANG Haina SONG 《Asian Agricultural Research》 2024年第4期41-47,共7页
Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing ... Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing the role of collaborative education.In order to realize the seamless integration of inorganic and analytical chemistry courses and ideological and political education,this paper summarizes the current situation of ideological and political research on inorganic and analytical chemistry courses in three major databases in China(VIP,CNKI and Wanfang),and sorts out the knowledge points,ideological and political elements and educational goals according to the content of the course chapters,to provide a basic guarantee for the ideological and political education construction of the course. 展开更多
关键词 ENVIRONMENTAL and ECOLOGICAL engineering Ideological and POLITICAL MATERIALS TALENT training INORGANIC and analytical chemistry
下载PDF
Comparative Appraisal of Response Surface Methodology and Artificial Neural Network Method for Stabilized Turbulent Confined Jet Diffusion Flames Using Bluff-Body Burners
7
作者 Tahani S. Gendy Salwa A. Ghoneim Amal S. Zakhary 《World Journal of Engineering and Technology》 2020年第1期121-143,共23页
The present study was conducted to present the comparative modeling, predictive and generalization abilities of response surface methodology (RSM) and artificial neural network (ANN) for the thermal structure of stabi... The present study was conducted to present the comparative modeling, predictive and generalization abilities of response surface methodology (RSM) and artificial neural network (ANN) for the thermal structure of stabilized confined jet diffusion flames in the presence of different geometries of bluff-body burners. Two stabilizer disc burners tapered at 30° and 60° and another frustum cone of 60°/30° inclination angle were employed all having the same diameter of 80 (mm) acting as flame holders. The measured radial mean temperature profiles of the developed stabilized flames at different normalized axial distances (x/dj) were considered as the model example of the physical process. The RSM and ANN methods analyze the effect of the two operating parameters namely (r), the radial distance from the center line of the flame, and (x/dj) on the measured temperature of the flames, to find the predicted maximum temperature and the corresponding process variables. A three-layered Feed Forward Neural Network in conjugation with the hyperbolic tangent sigmoid (tansig) as transfer function and the optimized topology of 2:10:1 (input neurons: hidden neurons: output neurons) was developed. Also the ANN method has been employed to illustrate such effects in the three and two dimensions and shows the location of the predicted maximum temperature. The results indicated the superiority of ANN in the prediction capability as the ranges of R2 and F Ratio are 0.868 - 0.947 and 231.7 - 864.1 for RSM method compared to 0.964 - 0.987 and 2878.8 7580.7 for ANN method beside lower values for error analysis terms. 展开更多
关键词 STABILIZED TURBULENT Flames BLUFF-BODY Burners Thermal Structure Modeling Artificial NEURAL NETWORK Response Surface methodology Multi-Layer PERCEPTRON Feed Forward NEURAL NETWORK
下载PDF
Voltammetric Study of the Interaction between Melamine and DNA on a Carboxylic Acid-Functionalized Nano-Fe<sub>3</sub>O<sub>4</sub>Modified Electrode and Its Analytical Application for Melamine Determination in Liquid Milk Samples
8
作者 Ke Chen Haoyu Shen +2 位作者 Zhejun Wang Amen Zhou Qinghua Xia 《American Journal of Analytical Chemistry》 2015年第4期263-273,共11页
Carboxylic acid-functionalized nano-sized magnetic composite polymers (COOH-NMPs) were synthesized and used for the preparation of the modified glassy carbon electrode, i.e., COOH-NMPs/GCE and DNA/COOH-NMPs/GCE. The e... Carboxylic acid-functionalized nano-sized magnetic composite polymers (COOH-NMPs) were synthesized and used for the preparation of the modified glassy carbon electrode, i.e., COOH-NMPs/GCE and DNA/COOH-NMPs/GCE. The electrochemical behaviors of melamine (MM) were investigated on COOH-NMPs/GCE by cyclic voltammetry (CV) in both cases of DNA in the solution and immobilized on the electrode surface. The electron transfer coefficient (a) and the rate constant (ks) kept unchanged in the absence and presence of DNA. Based on the electrochemical properties of the interaction of MM on the surface of the DNA/COOH-NMPs/GCE, a direct method for the determination of MM in liquid milk was established. The detection limit of this method was 2.0 ng·L﹣1, with average recoveries at 95.9% - 104.2% and RSD at 4.5% - 8.2%. The proposed method was provided to have a good accuracy, high stability and good reproducibility with a simple and environmental friendly process. 10 kinds of liquid milk samples bought from the market randomly were tested, and only 1 of them was found at relatively low level of MM residue with the amount of 0.12 ug·L﹣1. 展开更多
关键词 Carboxylic Acid-Functionalized Nano-Sized Magnetic Composite Polymers (NMPs) MELAMINE (MM) HERRING Sperm DNA (HS-DNA) Interaction analytical Application Determination of MELAMINE
下载PDF
试论ELT Methodology课程的教学改革与创新
9
作者 吴琼 《南平师专学报》 2004年第1期98-102,共5页
目前 ,如何教好英语已成为英语作为外语教学的探讨的热点。作为一名教师 ,纯粹地依靠掌握一些语言知识去教学是远远不够的 ,因此对于师资的专门培训显得尤为重要。然而师范院校中的“英语教学法课程”却是师资培训的最初步 ,最基本 ,也... 目前 ,如何教好英语已成为英语作为外语教学的探讨的热点。作为一名教师 ,纯粹地依靠掌握一些语言知识去教学是远远不够的 ,因此对于师资的专门培训显得尤为重要。然而师范院校中的“英语教学法课程”却是师资培训的最初步 ,最基本 ,也是最重要的课程。本文着眼于改变传统的“英语教学法课程”的教学模式 ,倡导此课程的教学改革 ,将理论与实践相结合 ,鼓励学生在模拟教学中进行反思 ,以确保学生在未来的教师生涯中 ,能坚持不懈地提高自身的职业素质。 展开更多
关键词
下载PDF
Response surface methodology-based hybrid robust design optimization for complex product under mixed uncertainties 被引量:1
10
作者 WAN Liangqi CHEN Hongzhuan OUYANG Linhan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第2期308-318,共11页
Minimizing the impact of the mixed uncertainties(i.e.,the aleatory uncertainty and the epistemic uncertainty) for a complex product of compliant mechanism(CPCM) quality improvement signifies a fascinating research top... Minimizing the impact of the mixed uncertainties(i.e.,the aleatory uncertainty and the epistemic uncertainty) for a complex product of compliant mechanism(CPCM) quality improvement signifies a fascinating research topic to enhance the robustness.However, most of the existing works in the CPCM robust design optimization neglect the mixed uncertainties, which might result in an unstable design or even an infeasible design. To solve this issue, a response surface methodology-based hybrid robust design optimization(RSM-based HRDO) approach is proposed to improve the robustness of the quality characteristic for the CPCM via considering the mixed uncertainties in the robust design optimization. A bridge-type amplification mechanism is used to manifest the effectiveness of the proposed approach. The comparison results prove that the proposed approach can not only keep its superiority in the robustness, but also provide a robust scheme for optimizing the design parameters. 展开更多
关键词 response surface methodology (RSM) HYBRID robust design optimization (HRDO) uncertainty complex product of compliant mechanism (CPCM)
下载PDF
地质样品Sr同位素激光原位等离子体质谱(LA-MC-ICP-MS)测定 被引量:16
11
作者 杨岳衡 吴福元 +2 位作者 谢烈文 杨进辉 张艳斌 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第12期3431-3441,共11页
Sr同位素在研究岩浆演化及其源区具有重要的示踪作用。MC-ICP-MS的出现为具有高Sr含量地质样品的激光原位Sr同位素测定变成了现实。本文利用Netpune MC-ICP-MS和193nm准分子激光联机,通过滨珊瑚、斜长石、磷灰石和钙钛矿等系列实验,建... Sr同位素在研究岩浆演化及其源区具有重要的示踪作用。MC-ICP-MS的出现为具有高Sr含量地质样品的激光原位Sr同位素测定变成了现实。本文利用Netpune MC-ICP-MS和193nm准分子激光联机,通过滨珊瑚、斜长石、磷灰石和钙钛矿等系列实验,建立了激光原位Sr同位素测定方法。实验结果表明,激光Sr同位素测定中Kr、Rb和稀土元素二价离子的干扰能够有效扣除,而钙聚合物的干扰在Neptune型MC-ICP-MS并不显著。不同激光参数的实验表明,大激光束斑产生更高信号强度,因而Sr同位素精度更高,同一激光束斑大小,激光脉冲频率对Sr同位素精度无明显影响。 展开更多
关键词 natural isotopic measurement inductively coupled plasma analytical procedure spatial resolution mass spectrometry analysis in-situ PORITES coral excimer laser significant development spot size
下载PDF
Analytical Methods in the Quality Control of Scientific Publications Part V: The Fraud of Pseudoscientists Based on False Measurements and Method Development
12
作者 Ilia Brondz 《International Journal of Analytical Mass Spectrometry and Chromatography》 2015年第2期25-31,共7页
Despite the obvious frauds published in [1] [2] and the involvement of Editors and Editors in Chief of the journals in the publication of these fraudulent papers, the Editors in Chief of publishers have not taken any ... Despite the obvious frauds published in [1] [2] and the involvement of Editors and Editors in Chief of the journals in the publication of these fraudulent papers, the Editors in Chief of publishers have not taken any action to retract the fraudulent papers or to dismiss the corrupt editors. By this passivity, these Editors in Chief are supporting plagiarism, dissemination of fraudulent data, lies and making published information unreliable. In the present paper, we evaluate examples of bold, fraudulent publications and give the names of some Editors directly participating in concealing fraudulent publications, together with the names of Editors in Chief who also concealed and covered the facts of fraud and were reluctant to remove the fraudulent papers from circulation or to remove cheaters from editorial positions. The truth is universal and international;in contrast, the lie is individual and partisan, social, political, confessional, cultural and dirty. Knowledge is a truth that is part of the Universe. Lies are a tool of manipulation and can exist only in distinct environments that produce and support them. In this paper, we will show how artificial prefabricated analytical procedures were used to disseminate false data with the aim of substituting the truth with fraud. 展开更多
关键词 PLAGIARISM DISSEMINATION of False Data False Method Development Corrupt EDITORS Artificial analytical Procedures PRIMAQUINE Quinocide ANTIMALARIAL Drugs
下载PDF
A Study of Sediments and Radioactive Particles of the Yenisei River Using a Variety of Analytical Methods
13
作者 A. Bolsunovsky M. Melgunov 《Journal of Geoscience and Environment Protection》 2014年第3期153-158,共6页
The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by a Russian nuclear facility producing weapon-grade plutonium, which has been in operation for many ye... The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by a Russian nuclear facility producing weapon-grade plutonium, which has been in operation for many years. Examination of Yenisei River sediment samples revealed the presence of artificial radionuclides typical of radioactive discharge from the Mining-and-Chemical- Combine (MCC) nuclear facility: isotopes of europium (152Eu, 154Eu, and 155Eu), cesium (137Cs and 134Cs), 60Co, 90Sr, and transuranium elements. The MCC is also a source of radioactive particles in the Yenisei. New data on radionuclide concentrations in sediments and radioactive particles in the Yenisei River were obtained using a wide range of analytical methods. Sequential extraction performed on samples of sediment cores showed different degrees of potential environmental availability of artificial radionuclides and uranium. In a few samples, 241Am was present in the unextractable form, which may be accounted for by the presence of microparticles of the reactor fuel. These microparticles were investigated using scanning electron microscopy, and their reactor origin was confirmed. 展开更多
关键词 Yenisei RIVER SEDIMENTS Artificial and Natural Radionuclides RADIOACTIVE Particles Sequential Extraction RADIONUCLIDE Composition and SPECIATION analytical Methods
下载PDF
Analytical Solution of Van Der Pol’s Differential Equation Using Homotopy Perturbation Method
14
作者 Md. Mamun-Ur-Rashid Khan 《Journal of Applied Mathematics and Physics》 2019年第1期1-12,共12页
In this research work, Homotopy perturbation method (HPM) is applied to find the approximate solution of the Van der Pol Differential equation (VDPDE), which is a well-known nonlinear ODE. Firstly, the approximate sol... In this research work, Homotopy perturbation method (HPM) is applied to find the approximate solution of the Van der Pol Differential equation (VDPDE), which is a well-known nonlinear ODE. Firstly, the approximate solution of Van Der Pol equation is developed using Dirichlet boundary conditions. Then a comparison between the present results and previously published results is presented and a good agreement is observed. Finally, HPM method is applied to find the approximate solution of VDPDE with Robin and Neumann boundary conditions. 展开更多
关键词 HOMOTOPY Perturbation Method (HPM) Van Der POL DIFFERENTIAL Equation (VDPDE) Nonlinear DIFFERENTIAL Equations Analytic Solution Boundary Conditions
下载PDF
Analytical Framework for Market-oriented DSR Flexibility Integration and Management 被引量:1
15
作者 Shi You Junjie Hu +1 位作者 Kai Heussen Chunyu Zhang 《Energy and Power Engineering》 2013年第4期1367-1371,共5页
Integration and management of the flexibility of Demand Side Resources (DSR) in today’s energy systems plays a significant role in building up a sustainable society. However, the challenges of understanding, predicat... Integration and management of the flexibility of Demand Side Resources (DSR) in today’s energy systems plays a significant role in building up a sustainable society. However, the challenges of understanding, predicating and handling the uncertainties associated this subject to a great extent hamper its development. In this paper, an analytical framework based on a multi-portfolio setup in presence of a deregulated power market is proposed to address such challenges by adopting the thinking in modern portfolio theory (MPT). A Numerical example that targets on analyzing the risk and return for various flexibility pricing strategies are presented to illustrate some features of the framework. 展开更多
关键词 analytical FRAMEWORK Distributed Energy Resources Flexiblity Deregulated Power Market Morden PORTFOLIO Theory Risk and RETURN
下载PDF
Digital Economy: A Vision From The Future
16
作者 Valentina Bondarenko 《Journal of Economic Science Research》 2020年第1期16-23,共8页
The article shows that the foundation of the digital economy can be a new paradigm for predicting the future from the future,i.e.from the future in which the development goal has already been achieved.This allows to m... The article shows that the foundation of the digital economy can be a new paradigm for predicting the future from the future,i.e.from the future in which the development goal has already been achieved.This allows to minimize all costs and completely avoid incorrect system solutions of the existing trial-and-error approach.Using the achievements of the technological revolution of Industry 4.0,an effective digital economy can be formed only when it is seen as an economy of coordinated interests between the state,business,society and the interests of each individual in real time at every local level.This will make it possible to solve the problem of ensuring the high quality of life not of citizens in general,but of each individual. 展开更多
关键词 Glushkov VM OGAS Scientific and technical progress Industry 4.0 Digital economy CRISIS New methodological tools GOAL Complexity Integrity CONSISTENCY Interdisciplinarity A SINGLE indicator A SINGLE criterion of efficiency Forecasting the FUTURE from the FUTURE
下载PDF
啤酒中阿拉伯木聚糖的溶解、降解及堵塞膜机制的研究 被引量:5
17
作者 李胤 陆健 顾国贤 《啤酒科技》 2005年第5期19-32,共14页
阿拉伯木聚糖是谷物细胞壁中的一种非淀粉质多糖,在啤酒酿造过程中,阿拉伯木聚糖会造成浸出率降低、麦汁黏度升高、影响麦汁和啤酒过滤(尤其是纯生啤酒的膜过滤)、成品啤酒浑浊等.本文系统的研究了谷物中阿拉伯木聚糖的结构、理化性质... 阿拉伯木聚糖是谷物细胞壁中的一种非淀粉质多糖,在啤酒酿造过程中,阿拉伯木聚糖会造成浸出率降低、麦汁黏度升高、影响麦汁和啤酒过滤(尤其是纯生啤酒的膜过滤)、成品啤酒浑浊等.本文系统的研究了谷物中阿拉伯木聚糖的结构、理化性质和对酿造的影响;比较了气相色谱法和比色法测定阿拉伯木聚糖;报道了阿拉伯木聚糖在酿造过程中含量的变化,并以小麦和小麦芽为辅料,系统的研究了糖化温度、谷物粒径和料水比对阿拉木聚糖在糖化过程中溶解的影响;在热力学和动力学方程的基础上,建立了糖化过程中预测内切木聚糖酶和阿拉伯木聚糖的模型;通过电子显微镜手段表征了不同分子量阿拉伯木聚糖对膜过滤的影响;运用响应面分析法,采用木聚糖酶优化了酶解阿拉伯木聚糖的条件. 展开更多
关键词
下载PDF
Application of Response Surface Methodology for Optimization of Fluoride Removal Mechanism by Newely Developed Biomaterial 被引量:3
18
作者 Ria Bhaumik Naba Kumar Mondal +1 位作者 Soumya Chattoraj Jayanta Kumar Datta 《American Journal of Analytical Chemistry》 2013年第8期404-419,共16页
The adsorption capacities of new biomaterials derived from lemon leaf (Citrus sp.) toward fluoride ions have been explored by varying different physicochemical parameters such as pH, initial concentration, adsorbent d... The adsorption capacities of new biomaterials derived from lemon leaf (Citrus sp.) toward fluoride ions have been explored by varying different physicochemical parameters such as pH, initial concentration, adsorbent dose, contact time, stirring rate and temperature. The entire study was done through batch process. Maximum fluoride adsorption of 96.9% - 98.8% was achieved with an initial concentration of 10 mg/L. Langmuir isotherm model well expressed fluoride ad- sorption onto LLD-1, LLD-2 and LLD-3. According to correlation coefficient, the fluoride adsorption onto these 3 ad- sorbents was correlated well with pseudo-second-order kinetic model. From thermodynamic study, the spontaneous nature and feasibility of the adsorption process with negative enthalpy (&#916H0) value also supported the exothermic nature were shown. The rate of fluoride adsorption was mathematically described as a function of experimental parameters and was modeled through Box-Behnken (Response surface methodology). The results showed that the responses of fluoride adsorption were significantly affected by the quadratic term of pH, initial concentration, contact time and temperature and the statistical analysis was performed by ANOVA which indicated good correlation of experimental parameters. 展开更多
关键词 LEMON Leaf FLUORIDE Adsorption LANGMUIR ISOTHERM Pseudo-Second-Order Kinetic Model THERMODYNAMIC Study Response Surface methodology
下载PDF
层次分析法在江河源区高寒草地退化研究中的应用 被引量:60
19
作者 周华坤 赵新全 +3 位作者 周立 唐艳鸿 刘伟 师燕 《资源科学》 CSSCI CSCD 北大核心 2005年第4期63-70,共8页
以江河源区退化高寒草甸为对象,利用层次分析法,探讨了高寒草地的退化原因和恢复治理措施的有效性。结果表明:长期超载过牧和暖干化气候是导致高寒草甸退化的主导因子,贡献率为65·99%;伴随草地初始退化出现的鼠虫和毒杂草泛滥危害... 以江河源区退化高寒草甸为对象,利用层次分析法,探讨了高寒草地的退化原因和恢复治理措施的有效性。结果表明:长期超载过牧和暖干化气候是导致高寒草甸退化的主导因子,贡献率为65·99%;伴随草地初始退化出现的鼠虫和毒杂草泛滥危害是加速高寒草甸退化的重要因子,贡献率为15·03%;人类不合理干扰造成的高寒草甸退化也不应忽视,贡献率为9·64%。各个恢复治理措施组合权重的分配格局相对均衡,其中围栏封育和划区轮牧(E2)与控制放牧强度(E1),效益较好,组合权重达0·3007。层次分析法可为草原管理,防止草地退化、恢复治理退化草地、优化利用草地资源提供定量依据。 展开更多
关键词 退 退 退
下载PDF
残留农药的光学检测技术和去噪处理 被引量:1
20
作者 王玉田 张立梅 Yu-tian Li-mei 《计量学报》 CSCD 北大核心 2009年第6期-,共4页
根据残留农药受到紫外光激发能够发出荧光的机理,研究了一种用于测量残留农药浓度的荧光光纤测量系统.该系统采用脉冲氙灯作为激发光源,光纤探测并传输荧光,电荷耦合器(CCD)作为荧光检测系统的光电转换器件.由于荧光是微弱信号,系统采... 根据残留农药受到紫外光激发能够发出荧光的机理,研究了一种用于测量残留农药浓度的荧光光纤测量系统.该系统采用脉冲氙灯作为激发光源,光纤探测并传输荧光,电荷耦合器(CCD)作为荧光检测系统的光电转换器件.由于荧光是微弱信号,系统采用微弱信号处理电路对CCD输出信号进行了处理,并且采用相关双采样技术有效地抑制了CCD输出噪声的干扰.用该系统对吡虫啉溶液进行荧光分析,实现了对吡虫啉的快速测定,在5~100μg/L范围内,荧光强度和浓度基本呈线性关系,线性相关系数为0.9959. Abstract: Based on the mechanism that pesticide can emit fluorescence in the ultraviolet light, a fluorescence fiber- optical measuring system is developed for monitoring its concentration. This system makes use of pulse xenon lamp as exciting light source, the optical fiber detects and transmits the fluorescence, charge coupled device (CCD) is used to photo-electricity transformation component of fluorescence measuring system. Because fluorescence is a weak signal, the system uses the weak signal processing circuit to carry on processing to the CCD output signal and uses the correlated double sample technique to control the disturbance Of CCD output noise effectively. Carting on the fluorescence analysis with this system to the imidaeloprid, the imidacloprid fast determination was realized. In the scope of 5~100 μg/L, the fluorescence intensity and the density assume the linear relations, the linear correlation coefficient is basically 0. 9959. 展开更多
关键词 FLUORESCENCE intensity measuring system correlation coefficient weak SIGNAL FLUORESCENCE analysis EXCITING LIGHT source CCD ultraviolet LIGHT SIGNAL processing transformation output SIGNAL optical fiber 线
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部