Effect of the distributor plugging ways on fluidization quality and particle stratification in air dense medium fluidized bed

Gas-solid fluidized bed separation is a highly efficient and clean technique for coal separation,and can effectively remove ash and sulfur contained gangue minerals from coal.However,the fine coal plugging distributor often leads to uneven fluidization and affects the separation effect.In this paper,different plugging ways were designed to study their effects on the fluidization characteristics and particle mixing.It was found that when the plugging phenomenon occurs,the minimum fluidization velocity of the fluidized bed gradually decreases as the plugging area enlarges.The difference between the top and the bottom of the bed minimum fluidization velocity increases accordingly,and a“stagnation phenomenon”occurs in the bed.The standard deviation of pressure fluctuations at the top of the bed is smaller than that at the bottom of the bed,which is the opposite of normal conditions.As the area of the plugging increases,the dead zone on the side wall of the fluidized bed significantly increases.The size of the dead zone is rapid reducing at the initial stage.It was noticed that the stratification of the low-density products is particularly affected by plugging,whereas the stratification of high-density products is not obviously influenced by certain conditions.

Prediction of Soil Erosion on Different Underlaying Surface in Construction Period of Xichang to Panzhihua Expressway

In order to investigate the behavior of soil erosion on the slope of the different underlaying surface during construction, the experiment with natural rainfall on Xichang-Panzhihua highway was conducted, to quantify the runoff and soil loss. The results show that. （1） the main type of soil erosion is gully erosion, the amount of soil erosion caused by gully erosion is higher than that by surface erosion. （2） The principal factor causing soil erosion on the slope of the embankment is individual amount of precipitation, the width of the embankment and rain intensity. （3） The principal factor causing soil erosion on the cutting slope is individual amount of precipitation, the width of the cutting slope and rain intensity. （4） The principal factor causing soil erosion on the slope of the dumped soil area is individual amount of precipitation, the width of the flat roof and rain intensity. There are well linear relationships between the amount of soil erosion and the principal factor, and their correlation coefficient are 0.935 7-0.999 8.

Spatio-temporal analysis of phenology in Yangtze River Delta based on MODIS NDVI time series from 2001 to 2015

Phenology has become a good indicator for illustrating the long-term changes in the natural resources of the Yangtze River Delta.However,two issues can be observed from previous studies.On the one hand,existing time-series classification methods mainly using a single classifier,the discrimination power,can become deteriorated due to fluctuations characterizing the time series.On the other hand,previous work on the Yangtze River Delta was limited in the spatial domain (usually to 16 cities)and in the temporal domain (usually 2000-2010).To address these issues,this study attempts to analyze the spatiotemporal variation in phenology in the Yangtze River Delta (with 26 cities,enlarged by the state council in June 2016), facilitated by classifying the land cover types and extracting the phenological metrics based on Moderate Resolution Imaging Spectrometer (MODIS)Normalized Difference Vegetation Index (NDVI)time series collected from 2001 to 2015.First,ensemble learning (EL)-based classifiers are used for land cover classification,where the training samples (a total of 201,597)derived from visual interpretation based on GlobelLand30 are further screened using vertex component analysis (VCA),resulting in 600 samples for training and the remainder for validating. Then,eleven phenological metrics are extracted by TIMESAT (a package name)based on the time series, where a seasonal-trend decomposition procedure based on loess (STL-decomposition)is used to remove spikes and a Savitzky-Golay filter is used for filtering.Finally,the spatio-temporal phenology variation is analyzed by considering the classification maps and the phenological metrics.The experimental results indicate that:1)random forest (R.F)obtains the most accurate classification map (with an overall accuracy higher than 96%);2)different land cover types illustrate the various seasonalities;3)the Yangtze River Delta has two obvious regions,i.e.,the north and the south parts,resulting from different rainfall, temperature,and ecosystem conditions;4)the phenology variation over time is not significant in the study area;5)the correlation between gross spring greenness (GSG) and gross primary productivity (GPP)is very high, indicating the potential use of GSG for assessing the carbon flux.

Palladium/Copper Cocatalyzed Coupling Reaction of Aroyl Hydrazides with Indoles

与简单 aroyl 一种肺结核特效药联合吲哚的反应的崭新的钯 / 铜 cocatalyzed 在氧气的条件下面被开发了。aroyl 一种肺结核特效药的一个范围经历了钯 / 铜 cocatalyzed 有对在 dimethyl sulfoxide 和 nitromethane 的 1:1 混合物的空气开放的吲哚的氧化 arylation 节制给在结构上多样的 2-arylindoles 或 3-arylindoles 在里面到好收益。反应很好容忍许多功能的组象 alkoxy 那样，光圈，酉旨。

Room-Temperature Bismuth-Catalyzed Bis-arylation of Carbonyl Compounds with Aryl Ethers and Phenols

用 Bi2 (SO4 ) ， 3 顺利在房间温度与芳基醚作为添加剂，许多醛，酉同类，和缩荃是的催化剂和 TMSCl 压缩了有选择地提供相应 diarylmethanes 和 triarylmethanes 在对优秀收益好。

Catalytic C-N Bond Alkynylation of N-Benzylic Sulfonamides with Terminal Alkynes

A new cross-coupling reaction of N-benzylic sulfonamides with terminal alkynes for the synthesis of internal alkynes is reported.In the presence of 5 mol%of(Tf)_(2)NH/Bi(OTf)_(3)(1∶1),a broad range of N-benzylic sulfona-mides react smoothly with arylacetylenes to afford structurally diverse internal alkynes in moderate to excellent yields.We reasoned that vinyl cations could be formed by the regioselective attack of terminal alkynes with benzyl cations generated in situ from N-benzylic sulfonamides under acidic conditions,which then eliminated to form a carbon-carbon triple bond.

TfOH/Fe（OTf）3 Cocatalyzed Reaction of Arylallenes with Alcohols for Structurally Diverse Indene Derivatives

The indene moiety is an important unit because of its presence in many chemical catalysts, functional materials and biologically relevant molecules. Herein, we report a facile reaction of arylallenes with benzylic or allylic alcohols through TfOH/Fe（OTf）3 cocatalyzed cleavage of sp3 carbon-oxygen. In the presence of 5 mol% TfOH and 5 mol% Fe（OTf）3, a range of arylallenes undergo carbocation initiated cyclization reaction with alkyl alcohols to give structurally diverse polysubstituted indenes in good to excellent yields. H2O is the sole byproduct that makes this transformation highly atom-economic and environmentally benign.

An Efficient Prins Cyclization for Stereoselective Synthesis of Tetrahydropyran from Imines and Homoallyl Alcohols

An unprecedented protocol has been developed for the efficient synthesis of substituted tetrahydropyrans via a bismuth-promoted Prins cyclization of imines with homoallyl alcohols.In the presence of 40 mol%BiCl_(3),a wide variety of imines react smoothly with homoallyl alcohols at room temperature to give the corresponding 4-chlorotetrahydropyran derivatives in good to excellent yields.