检索结果-南通市图书馆

Modified Activated Carbon as Solid Phase Extraction Adsorbent for the Preconcentration and Determination of Trace As（Ⅲ） in Environmental Samples by Graphite Furnace Atomic Absorption Spectrometry

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 Chemistry 2012年第3期30卷 665-669页

作者： Tavakkoli,Nahid Habibollahi,Saeed Amini Tehrani,shahla Department of Chemistry Payame Noor University19395-4697 TehranIran

A simple and selective method was developed for the preconcentration, separation, and determination of trace amounts of As（Ⅲ） in an aqueous solution by solid phase extraction combined with graphite furnace atomic absorption spectrometry. Activated carbon （AC） was modified by sodium diethyldithiocarbamate （NaDDTC） and then used as a new, stable and easily prepared solid sorbent in a mini column for the extraction of As（Ⅲ） in aqueous solution. Factors influencing the sorption and desorption of As（Ⅲ）, such as volume and concentration of eluent, sam- ple pH, flow rate and effect of interfering ions on the recovery of As（Ⅲ） have been systemically investigated. At pH 2.0 As（Ⅲ） could be adsorbed quantitatively by NaDDTC-AC, and then eluted completely with 2 mL of 3.0 moloL 1 HNO3. The amount of eluted As（Ⅲ） was measured using graphite furnace atomic absorption spectrometry. The detection limit of As（Ⅲ） was 0.04 ng·mL-1 with enrichment factor of 100 and the relative standard deviation （RSD, n=8） was 1.58% at 10 ng·mL-1 level.

关键词： activated carbon preconcentration arsenic solid phase extraction adsorption graphite furnace atomicabsorption spectrometry

Isolation and Identification of the Major Chemical Components Found in the Upper Parts of Teucrium Pofium Plants Grown in Khuzestan Province of Iran

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 Chemistry 2007年第8期25卷 1171-1173页

作者： ASHNAGAR Alamdar GHARIB NASERI Nahid FOROOZANFAR shahla School of Pharmacy Ahwaz Jundi Shapour University of Medical Sciences Ahwaz Iran Ahwaz Faculty of Petroleum Engineering Petroleum University of Technology Ahwaz Iran

Teucrium polium is a dwarf sub-shrub usually 30-60 cm high with many branches, which is fairly distributed throughout Iran, with its flowering being season mainly from April to July. The plant was collected during its flowering season in Baghmalek region in the North-East of Khuzestan province, Iran. After the identification of the genus, species and variety of the plant, the dried whole plant （flowers, fruits and the leaves） was steam distilled with different methods. The isolated essential oil was dried over anhydrous sodium sulphate and stored at 4-6 ℃. Analysis of the essential oil was carried out by GC-MS technique. At least 10 major components were identified （3-carene/α-pinene, β-phellandrene, limonene, germacrene, β-bourbonene, β-caryophylene, γ-muurolene, γ-elemene, spathulenol, β-eudesmol）（totally 97.02%）. Also, successive TLC and column chromatography of the essential oil resulted in the separation of four fractions. Based upon 1^H NMR, IR and mass spectra, the fractions with Rf=0.12 and 0.93 were determined as gualol and a mixture of α-pinene, β-phellandrene and limonene, respectively.

关键词： teucrium polium labiatae germander α-pinene β-phellandrene limonene guaiol GC-mass analysis

Integrating water use systems and soil and water conservation measures into a hydrological model of an Iranian Wadi system

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 Arid Land 2020年第4期12卷 545-560页

作者： Nariman mahmoodi Jens KIESEL Paul D WAGNER Nicola FOHRER Department of Hydrology and Water Resources Management Institute for Natural Resource ConservationKiel UniversityKiel 24118Germany Department of Ecosystem Research Leibniz-Institute of Freshwater Ecology and Inland Fisheries(IGB)Berlin 12489Germany

Water resources are precious in arid and semi-arid areas such as the Wadis of Iran. To sustainably manage these limited water resources, the residents of the Iranian Wadis have been traditionally using several water use systems(WUSs) which affect natural hydrological processes. In this study, WUSs and soil and water conservation measures(SWCMs) were integrated in a hydrological model of the Halilrood Basin in Iran. The Soil and Water Assessment Tool(SWAT) model was used to simulate the hydrological processes between 1993 and 2009 at daily time scale. To assess the importance of WUSs and SWCMs, we compared a model setup without WUSs and SWCMs(Default model) with a model setup with WUSs and SWCMs(WUS-SWCM model). When compared to the observed daily stream flow, the number of acceptable calibration runs as defined by the performance thresholds(Nash-Sutcliffe efficiency(NSE)≥0.68, –25%≤percent bias(PBIAS)≤25% and ratio of standard deviation(RSR)≤0.56) is 177 for the Default model and 1945 for the WUS-SWCM model. Also, the average Kling–Gupta efficiency(KGE) of acceptable calibration runs for the WUS-SWCM model is higher in both calibration and validation periods. When WUSs and SWCMs are implemented, surface runoff(between 30% and 99%) and water yield(between 0 and 18%) decreased in all sub-basins. Moreover, SWCMs lead to a higher contribution of groundwater flow to the channel and compensate for the extracted water by WUSs from the shallow aquifer. In summary, implementing WUSs and SWCMs in the SWAT model enhances model plausibility significantly.

关键词： SWAT model stream flow Wadis multi-metric framework water use systems soil and water conservation measures Halilrood Basin

CFD-DEM simulation of a pseudo-two-dimensional spouted bed comprising coarse particles

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Particuology 2019年第2期17卷 171-180页

作者： B. mahmoodi S.H. Hosseini G. Ahmadi llam Gas Treating Company llam Iran Department of Chemical Engineering llam University llam 69315-516 Iran Department of Mechanical and Aeronautical Engineering Clarkson University Potsdam NY 13699-5725 USA

In the present study, computational fluid dynamics (CFD) and the discrete element method (DEM) are used in conjunction with the Eulerian-Lagrangian method to simulate a pseudo-two-dimensional spouted bed comprising coarse 6-mm particles. The open-source OpenFOAM code is used to solve the governing equations. The predicted vertical particle velocity along the bed axis, particle velocity profiles in the radial directi on, power spectral den sity, time-averaged particle velocity vectors, bed pressure drop, and solid flow pattern are evaluated and compared with existing experimental data. Good agreement is found between the CFD-DEM results and the measured data. It is also shown that the present CFD-DEM model accurately predicts the particle flow pattern throughout the bed. It is found that the drag force, solid stresses, and gravity play important roles in the CFD-DEM simulation of a spouted bed comprising coarse particles.

关键词： CFD-DEM Pseudo-2D spouted bed Hydrodynamics Coarse particles

LESSONS FOR THE US SYSTEM OF FINANCIAL ARBITRATION： A RESPONSIVE EMPIRICAL EXPLORATION OF ARBITRATION AND OMBUDSMAN SERVICES

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Law in China-Selected Publications from Chinese Universities 2013年第4期8卷 651-688页

作者： shahla F. Ali Assistant Professor at Faculty of Law University of Hong Kong Hong Kong China.

The United States largely relies on a system of arbitration to handle retail consumer financial disputes. This approach has undergone significant challenges in recent yearsparticularly in light of recent abuses of consumer credit arbitration mechanisms. This paper reports on the result of a non-randomized smalLn survey which we label the ＂Financial Dispute Study＂ aiming at evaluating the relative effectiveness of two major approaches to financial dispute resolution -- arbitration and ombudsman services. Nearly a hundred survey questionnaires were distributed to financial dispute resolution practitioners throughout the world. A total of forty-eight arbitrators and ombudsmen from East Asia, North America, Europe, the Middle East and Africa responded. In the Study the participants were asked how practitioners viewed the level of satisfaction, settlement rate and perceived increase or decrease in the use of the given method of financial dispute resolution -- whether arbitration or ombudsman service.

关键词：

Conserving natural resources through food loss reduction: Production and consumption stages of the food supply chain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Soil and Water Conservation Research 2018年第4期6卷 331-339页

作者： shahla M.Wunderlich Natalie M.Martinez Department of Nutrition and Food Studies Montclair State UniversityNJUSA

Globally, attention has been drawn to the increasingly alarming rates of food loss and waste (FLW) along the food supply chain (FSC) and its contributions to the depletion of the natural resources and rise in greenhouse gas emissions. Within the past decade, discovery of the rippling impacts of this interrelationship has generated an increased sense of urgency in efforts amongst scholars, global leaders, government and non-government agencies to research, and formulate comprehensive plans and goals to address and reduce the rates of global FLW. Not only does FLW lessen the quantity of available food, but also, the availability of the many natural resources required to produce food. This will become an important factor when the world population increases by more than 30% by the year 2050. Although advances have been made, still 1.3 billion tons of food are wasted every year due to various underlying causes and challenges. This enormous quantity of wasted food also represents an increase in usage of natural resources. In the United States (U.S.), food and agriculture consume up to 16% of energy, almost half of the land, and account for 67% of the nation's freshwater use (NRDC, 2017). The rate of natural resource depletion is not sustainable, and it endangers the ecosystem. Multiple reports have cited the first and last stages of the FSC as the most significant contributors of FLW and environmental resource depletion. This literature review attempts to provide a comprehensive assessment of the intricacies of the FSC, the multi-variable causes of global FLW at the production and consumption stages, its environmental implications and the necessary sustainability compliant actions.

关键词： Global sustainability Food loss and waste Food security Environmental impact Sustainable food future Food supply chain Natural resources

Design of a heterosubtypic epitope-based peptide vaccine fused with hemokinin-1 against influenza viruses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2015年第3期30卷 200-207页

作者： shahla Shahsavandi Mohammad Majid Ebrahimi Kaveh Sadeghi Homayoon Mahravani Razi Vaccine & Serum Research Institute Karaj 31975 Iran

Influenza viruses continue to emerge and re-emerge, posing new threats for public health. Control and treatment of influenza depends mainly on vaccination and chemoprophylaxis with approved antiviral drugs. Identification of specific epitopes derived from influenza viruses has significantly advanced the development of epitope-based vaccines. Here, we explore the idea of using HLA binding data to design an epitope-based vaccine that can elicit heterosubtypic T-cell responses against circulating H7N9, H5N1, and H9N2 subtypes. The hemokinin-1(HK-1) peptide sequence was used to induce immune responses against the influenza viruses. Five conserved high score cytotoxic T lymphocyte(CTL) epitopes restricted to HLA-A*0201-binding peptides within the hemagglutinin(HA) protein of the viruses were chosen, and two HA CTL/HK-1 chimera protein models designed. Using in silico analysis, which involves interferon epitope scanning, protein structure prediction, antigenic epitope determination, and model quality evaluation, chimeric proteins were designed. The applicability of one of these proteins as a heterosubtypic epitopebased vaccine candidate was analyzed.

关键词： epitope-based vaccine hemokinin-1 heterosubtypic immunity influenza virus

Adaptive Dimensional Learning with a Tolerance Framework for the Differential Evolution Algorithm

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Complex System Modeling and Simulation 2022年第1期2卷 59-77页

作者： Wei Li Xinqiang Ye Ying Huang Soroosh mahmoodi School of Information Engineering Jiangxi University of Science and TechnologyGanzhou 341000China School of Mathematical and Computer Science Gannan Normal UniversityGanzhou 341000China Soroosh Khorshid Iranian Co. Qazvin 999067Iran

The Differential Evolution(DE)algorithm,which is an efficient optimization algorithm,has been used to solve various optimization *** this paper,adaptive dimensional learning with a tolerance framework for DE is *** population is divided into an elite subpopulation,an ordinary subpopulation,and an inferior subpopulation according to the fitness *** ordinary and elite subpopulations are used to maintain the current evolution state and to guide the evolution direction of the population,*** inferior subpopulation learns from the elite subpopulation through the dimensional learning *** the global optimum is not improved in a specified number of iterations,a tolerance mechanism is *** the tolerance mechanism,the inferior and elite subpopulations implement the restart strategy and the reverse dimensional learning strategy,*** addition,the individual status and algorithm status are used to adaptively adjust the control *** evaluate the performance of the proposed algorithm,six state-of-the-art DE algorithm variants are compared on the benchmark *** results of the simulation show that the proposed algorithm outperforms other variant algorithms regarding function convergence rate and solution accuracy.

关键词： Differential Evolution(DE) tolerance mechanism dimensional learning parameter adaptation continuous optimization

Weathering and soils formation on different parent materials in Golestan Province,Northern Iran

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 Mountain Science 2016年第5期13卷 870-881页

作者： Maryam mahmoodi Farhad KI-IORMALI Arash AMINI Shamsollah AYOUBI Dept of Soil Science C-organ Uniuersity of Agricultural Sciences and Natural ResourceGorgan 49138-15739Ivan Dept ofG-eology Golestan UniversityGorgan 49138-15759Iran Dept of Soil Science College of AgricultureIsfahan University of TechnologyIsfahan 84156-83111Iran

Geochemical, mineralogical, and micromorphologieal characteristics of soils and their relevant parent rocks including loess, ignimbrite, sandstone and limestone were investigated to identify the soil-parent material uniformity and the weathering degree of soils in Golestan Province, northern Iran. Highly developed Caleixerolls and moderately developed Haploxerepts were formed on loess and limestone, respectively. In contrast, the soils formed on ignimbrite and sandstone were non- developed Entisols. Illite was the dominant clay mineral found in ignimbrite and sandstone in both the A horizon and parent material. In loess derived soils however, smectite was dominant especially in the Bt horizon compared to its parent material indicating partly to its pedogenic formation. In limestone, illite and vermiculite were dominant both in the A and C horizons. Ti/Zr ratio proved that the studied soils were closely related to their underlying parent materials geochemically. Chemical index of alteration （CIA）, micromorphological index of soil development （MISECA）, smectite/illite＋chlorite ratio and magnetic susceptibility were applied to investigate the degree of soil development. Results showed that the most and the least developed soils were those formed on loess deposits and limestone,respectively. Application of the different geochemical and pedogenetic approaches was proved to be useful in identifying the relevance of soils to their underlying parent materials and also their degree of development.

关键词： Parent material Soil formation Weathering index Loess Iran