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Phosphine-free conversion of alcohols into alkyl thiocyanates using trichloroisocyanuric acid/NH_4SCN

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Chinese Chemical Letters 2012年第1期23卷 77-80页

作者： Roya Azadi babak Mokhtari Mohamad-Ali Makaremi Department of Chemistry College of ScienceShahid Chamran UniversityAhvaz 61357-43337Iran

A convenient and efficient phosphine-free procedure for the one-pot conversion of primary,secondary and tertiary alcohols into the corresponding alkyl thiocyanates or alkyl isothiocyanates is described using trichloro... 详细信息

关键词： Phosphine-free Alcohol Thiocyanate Trichloroisocyanuric acid Thiocyanation

Effect of Ocean Iron Fertilization on the Phytoplankton Biological Carbon Pump

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Advances in Applied Mathematics and Mechanics 2011年第1期3卷 52-64页

作者： Adam Pan babak Pourziaei Huaxiong Huang Department of Mathematics and Statistics York UniversityTorontoOntarioCanada M3J 1P3 Program of Engineering Science University of TorontoTorontoOntarioCanada M5S 1A1

It has been proposed that photosynthetic plankton can be used as a biological carbon pump tp absorb and sequester carbon dioxide in the *** this paper,plankton population dynamics are simulated in a single stratified water column to predict carbon dioxide sequestering due to surface iron fertilization in deep *** a predator-prey model and realistic parameter values,iron fertilization was found to only cause temporary blooms up to 5 months in duration,and relatively small increases in adsorption of atmospheric CO_(2).

关键词： Phytoplankton carbon dioxide iron fertilization carbon pump

Comparison of the effects of acute and chronic psychological stress on metabolic features in rats

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第11期13卷 904-912页

作者： Fatemeh ROSTAMKHANI Homeira ZARDOOZ Saleh ZAHEDIASL babak FARROKHI Neuroscience Research Center Shahid Beheshti University of Medical SciencesTehranIran Department of Biology Shahre-Rey BranchIslamic Azad UniversityTehranIran Department of Physiology Faculty of MedicineShahid Beheshti University of Medical SciencesTehranIran Endocrine Research Center Research Institute for Endocrine SciencesShahid Beheshti University of Medical SciencesTehranIran Department of Immunology Faculty of MedicineShahid Beheshti University of Medical SciencesTehranIran

This study was aimed to compare the effects of acute and chronic psychological stress on metabolic factors. Forty-two male Wistar rats were divided into control and stressed groups. Stress was applied by a communication box acutely (1 d) and chronically (15 and 30 d). Blood sampling was carried out by retro-orbital-puncture method. The plasma levels of glucose, cholesterol, triglyceride, insulin, and corticosterone were measured. In addition, feed and water intake, latency to eat and drink, adrenal and body weights were determined. Acute and chronic psychological stress did not significantly change basal plasma corticosterone levels. However, immediately (1 min) after acute exposure to stress, plasma corticosterone level increased compared to that before stress exposure. Acute stress increased plasma insulin levels significantly. Fifteen days of stress exposure resulted in plasma glucose increase. Chronic stress significantly increased feed intake, latency to eat, and adrenal weight compared to acute stress. The body weights of both control and stressed groups increased markedly during the experiment. Homeostasis model assessment of insulin resistance (HOMA-IR) index did not change significantly in the stressed group. In conclusion, application of acute and chronic psychological stress leads to different metabolic and/or behavioral changes but the metabolic changes resulting from acute exposure to stress seem to be more pronounced.

关键词： Psychological stress Corticosterone Insulin Glucose Cholesterol Triglyceride

Ab initio prediction of fast non-equilibrium transport of nascent polarons in SrI2: a key to high-performance scintillation

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npj Computational Materials 2016年第1期2卷 77-83页

作者： Fei Zhou babak Sadigh Paul Erhart Daniel Åberg Physical and Life Sciences Directorate Lawrence Livermore National LaboratoryLivermoreCAUSA Department of Physics Chalmers University of TechnologyGothenburgSweden

The excellent light yield proportionality of europium-doped strontium iodide(SrI2:Eu)has resulted in state-of-the-artγ-ray detectors with remarkably high-energy resolution,far exceeding that of most halide *** this class of materials,the formation of self-trapped hole polarons is very ***,polaron formation is usually expected to limit carrier mobilities and has been associated with poor scintillator light-yield proportionality and *** using a recently developed first-principles method,we perform an unprecedented study of polaron transport in SrI2,both for equilibrium polarons,as well as nascent polarons immediately following a self-trapping *** propose a rationale for the unexpected high-energy resolution of *** identify nine stable hole polaron configurations,which consist of dimerised iodine pairs with polaron-binding energies of up to 0.5 *** are connected by a complex potential energy landscape that comprises 66 unique nearest-neighbour migration *** initio molecular dynamics simulations reveal that a large fraction of polarons is born into configurations that migrate practically barrier free at room ***,carriers created duringγ-irradiation can quickly diffuse away reducing the chance for nonlinear recombination,the primary culprit for non-proportionality and resolution *** conclude that the flat,albeit complex,landscape for polaron migration in SrI2 is a key for understanding its outstanding *** insight provides important guidance not only for the future development of high-performance scintillators but also of other materials,for which large polaron mobilities are crucial such as batteries and solid-state ionic conductors.

关键词： polaron equilibrium iodine

Heavy metals and their source identification in particulate matter(PM_(2.5)) in Isfahan City, Iran

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Journal of Environmental Sciences 2018年第10期30卷 166-175页

作者： Mohsen Soleimani Nasibeh Amini babak Sadeghian Dongsheng Wang Liping Fang Department of Natural Resources Isfahan University of Technology Isfahan's Department of Environment Division of Environmental Monitoring State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Faculty of Material Science and Chemistry China University of Geosciences

The presence of heavy metals（HMs） in particulate matters（PMs） particularly fine particles such as PM2.5 poses potential risk to the health of human being. The purpose of this study was to analyze the contents of HMs in PM2.5 in the atmospheric monitoring stations in Isfahan city,Iran, in different seasons between March 2014 and March 2015 and their source identification using principle component analysis（PCA）. The samples of PM2.5 were taken using a high volume sampler in 7 monitoring stations located throughout the city and industrial zones since March 2014 to March 2015. The HMs content of the samples was measured using *** results showed that the concentrations of As, Cd and Ni were in a range of 23–36, 1–12,and 5–76 ng/m3 at all the stations which exceeded the US-EPA standards. Furthermore,the concentrations of Cr and Cu reached to 153 and 167 ng/m3 in some stations which were also higher than the standard levels. Depending on the potential sources of HMs, their concentration in PM2.5 through the various seasons was different. PCA illustrated that the different potential sources of HMs in the atmosphere, showing that the most important sources of HMs originated from fossil fuel combustion, abrasion of vehicle tires, industrial activities（e.g., iron and steel industries） and dust storms. Management and control of air pollution of industrial plants and vehicles are suggested for decreasing the risk of the HMs in the region.

关键词： Air pollution Heavy metals Particulate matters Principle component analysis

Application of N-thiocyanatosuccinimide as a reagent for the facile conversion of epoxides into thiocyanohydrines

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Chinese Chemical Letters 2011年第1期22卷 21-24页

作者： babak Mokhtari Roya Azadi Samira Rahmani-Nezhad Department of Chemistry College of ScienceShahid Chamran UniversityAhvaz 61357-43337Iran

The use of in situ generated N-thiocyanatosuccinimide with NH4SCN offers an efficient reagent system for the conversion of epoxides into their corresponding thiocyanohydrines in good to high yields. The major advantages of this method are as follows： use of cheap reagent, high regioselectivity, simple availability of reagent, ease of workup of the reaction.

关键词： N-Thiocyanatosuccinimide Ring opening Epoxide Thiocyanohydrin

The effect of nanoparticles on wettability alteration for enhanced oil recovery: micromodel experimental studies and CFD simulation

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Petroleum Science 2019年第4期16卷 859-873页

作者： Peyman Rostami Mohammad Shari babak Aminshahidy Jalal Fahimpour Department of Petroleum Engineering Amirkabir University of Technology

The applications of nanotechnology in oilfields have attracted the attention of researchers to nanofluid injection as a novel approach for enhanced oil recovery. To better understand the prevailing mechanisms in such new displacement scenarios,micromodel experiments provide powerful tools to visually observe the way that nanoparticles may mobilize the trapped *** this work, the e ect of silicon oxide nanoparticles on the alteration of wettability of glass micromodels was investigated in both experimental and numerical simulation approaches. The displacement experiments were performed on the original water-wet and imposed oil-wet(after aging in stearic acid/n-heptane solution) glass micromodels. The results of injection of nanofluids into the oil-saturated micromodels were then compared with those of the water injection scenarios. The flooding scenarios in the micromodels were also simulated numerically with the computational fluid dynamics(CFD) method. A good agreement between the experimental and simulation results was observed. An increase of 9% and 13% in the oil recovery was obtained by nanofluid flooding in experimental tests and CFD calculations, respectively.

关键词： Nanoparticles Micromodel Wettability alteration Oil recovery CFD calculation

Diversity and biomass of different functional groups of herbaceous species along an altitudinal gradient in the semi-arid Zagros mountain forests of Iran

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Journal of Forestry Research 2020年第5期31卷 1723-1731页

作者： Hafizollah Shahriari Kambiz Abrari Vajari babak Pilehvar Mehdi Heydari Forestry Department Faculty of Agriculture and Natural ResourcesLorestan UniversityKhorramabadIran Forestry Department Natural Resources and Agriculture FacultyIlam UniversityIlamIran

The response of diversity and biomass of herbaceous functional groups along an altitudinal gradient in mountainous forests of southern Zagros,Khuzestan Province,Iran was studied by sampling vegetation in 30 circular 1000-m^2 plots in herb layer of the forest floor within 646–2447 m asl(lowland:2000 m asl).The most important herbaceous functional groups were classified based on two aspects of growth form:annuals–perennials,grasses–*** the relationship between the diversity,richness,evenness,biomass and elevation was *** results showed that the annual functional group in the low-and midland classes,and perennial functional group in the lowland class had the highest species diversity and evenness in annual and perennial functional groups,respectively(p<0.01).The perennials in the highland class had the maximum total,above-and belowground dry biomass(p<0.01).On the other hand,the forb functional group in the lowland class had the greatest species diversity,richness,and evenness(p<0.01)and in the highland class had the maximum total dry,above-and belowground dry biomass in the grass and forb functional groups(p<0.01).Increasing the diversity,richness,and species evenness resulted in a decrease in the plant dry biomass.

关键词： Biodiversity Biomass Herbaceous functional groups Zagros forests

Forecasting soil temperature at multiple-depth with a hybrid artificial neural network model coupledhybrid firefly optimizer algorithm

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Information Processing in Agriculture 2018年第4期5卷 465-476页

作者： Saeed Samadianfard Mohammad Ali Ghorbani babak Mohammadi Department of Water Engineering University of TabrizTabrizIran Engineering Faculty Near East University99138 NicosiaNorth CyprusMersin 10Turkey Department of Irrigation and Reclamation Engineering University of TehranKarajIran

Forecasting soil temperature at multiple depths is considered to be a core decision-making task for examining future changes in surface and sub-surface meteorological processes,land-atmosphere energy exchange,resilient agricultural systems for improved crop health and eco-environmental risk *** aim of this paper is to estimate monthly soil temperature(ST)at multiple depth:5,10,20,50 and 100 cm with a hybrid multi-layer perceptron algorithm integrated with the firefly optimizer algorithm(MLP-FFA).To develop the hybrid MLP-FFA model,the monthly ST and relevant meteorological variables for the city of Adana(Turkey)are collated for the period of 2000–*** of hybrid MLP-FFA model is drawn upon a limited set of predictors,denoted as soil depth,periodicity(or the respective month),air temperature,pressure and solar radiation,while the objective variable for MLP-FFA model is the forecasted ST at multiple *** the evaluate MLPFFA,statistical metrics applied to test the model’s performance are:the root mean square error(RMSE),mean absolute error(MAE),mean absolute percentage error(MAPE)and mean bias error(MBE)where the sign of the difference is also *** conjunction with statistical metrics,a Taylor diagram is utilized to visualize the degree of similarity between the observed and forecasted soil *** terms of the forecasted results,the hybrid MLPFFA model is seen to outperform the standalone MLP *** optimal MLP-FFA is attained for soil temperature forecasting at a depth of 20 cm(RMSE,MAPE of 0.546C,2.40%)whereas the optimal MLP is attained for soil temperature forecasting at a depth of 50 cm(RMSE of 0.544℃,2.21%).Conclusively,the study advocates through statistical metrics attained the better utility of the hybrid MLP-FFA hybrid *** its superior performance,it is ascertained that the hybrid MLP model integrated with Firefly optimizer is a qualified ancillary tool that can be applied to generate precise soil temperat

关键词： Artificial neural network Hybrid firefly algorithm Soil temperature Turkish State Meteorological Service