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Preparation of Anhydrate Phosphogypsum Binders

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武汉理工大学学报 2010年第17期32卷 193-195,200页

作者： YANG M XIE Y CHENG J k PANG Y School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550003China

In this work,phosphogypsum(PG) with a small amount of lime was thermally pretreated at 450 ℃ to produce anhydrate gypsum for the purpose of searching new ways for utilization of waste PG. Additives,k2SO4 and one selected seed crystal(SC),were used as activator for anhydrate PG. The hydration characteristics of the anhydrate PG binders were investigated by determination of the setting time,the ratio of hydrated anhydrate PG,the compressive strength development,and the microstructure of the hardenite. The resistance to water was studied by measuring mass loss of binders exposed to hydrodynamic water. Results suggest that activated by k2SO4 and SC,anhydrate PG hydrates much more rapidly than that without additives. The anhydrate PG binder with k2SO4 and SC has proper setting time and good strength developments. SEM photos show that the set binders have hydrated products of rodlike and regularly shaped crystals. Those crystals connected closely,and the hardenite has a compact structure,which is beneficial to the obtainment of good properties.

关键词： anhydrate PG binders activator hydration

Quantitative image analysis of celiac disease

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World Journal of Gastroenterology 2015年第9期21卷 2577-2581页

作者： Edward J Ciaccio Govind Bhagat Suzanne k Lewis Peter H Green Department of Medicine Celiac Disease CenterColumbia UniversityNew YorkNY 10032United States

We outline the use of quantitative techniques that are currently used for analysis of celiac *** processing techniques can be useful to statistically analyze the pixular data of endoscopic images that is acquired with standard or videocapsule *** is shown how current techniques have evolved to become more useful for gastroenterologists who seek to understand celiac disease and to screen for it in suspected *** directions for focus in the development of methodology for diagnosis and treatment of this disease are *** is evident that there are yet broad areas where there is potential to expand the use of quantitative techniques for improved analysis in suspected or known celiac disease patients.

关键词： Celiac disease Frequency analysis Motility Videoca

Structure and Combustion Characteristics of Methane/Air Premixed Flame under the Action of Wall

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Energy Engineering 2021年第4期118卷 1135-1154页

作者： Feiyang Li Jianfeng Pan Chenxin Zhang Evans k.Quaye Xia Shao School of Energy and Power Engineering Jiangsu UniversityZhenjiang212013China

In order to obtain the combustion characteristics of the CH4/Air premixed flame under the action of the wall interaction,a study on the impact of the jet flame on the wall at different separation distances was carried *** separation distance from the burner outlet to the lower surface of the wall is changed and the flame structure is obtained through *** temperature,velocity and reaction rate are obtained through numerical simulation,and the law of flame characteristics change is obtained through *** results show that as the separation distance increases,the premixing cone inside the flame gradually changes from a horn shape to a complete cone shape and the length of the premixing cone profile ***,the peak temperature and velocity of the mixture in the axial direction gradually increase,and the temperature and velocity in the radial direction first increase and then *** temperature gradient and velocity reach the maximum when the separation distance is 11 *** peaks of reactants(CH_(4))net reaction rate intermediate products(CO)and products(CO_(2),H_(2)O)on the axis and the axial distance corresponding to the peaks increase *** chemical reaction rate near the wall also gradually decreases with the increase of the separation distance.

关键词： Flame-wall interaction separation distance flame structure air flow temperature flow velocity reaction rate

Enhanced thermoelectric performance of Bi_(0.5)Sb_(1.5)Te_(3) via Ni-doping:A Shift of peak ZT at elevated temperature via suppressing intrinsic excitation

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Journal of Materiomics 2021年第6期7卷 1264-1274页

作者： Sahiba Bano D.k.Misra J.S.Tawale Sushil Auluck CSIR-National Physical Laboratory Dr.K.S.Krishnan MargNew Delhi110012India Academy of Scientific&Innovative Research(AcSIR) CSIR-NPL CampusNew Delhi110012India

Bi_(2)Te_(3)-based thermoelectric(TE)materials have been demonstrated to be a potential candidate for mainly thermoelectric cooling/refrigeration ***,minority charge carriers excitation at high temperature reduces thermopower which restricts these materials for the use in power *** present work,substitution of Ni on Sb site in Bi_(0.5)Sb_(1.5-x)NixTe_(3)(x=0,0.01,0.04 and 0.08)actuates the system to supress the intrinsic excitation leading to shift in highest ZT to higher temperature *** Density functional theory(DFT)calculations and experimental results reveal that Ni in Bi_(0.5)Sb_(1.5)Te3 provides the extra holes and slightly reduces the band gap Eg which enhances the s of Ni-doped Bi_(0.5)Sb_(1.5-x)NixTe_(3) samples and a at elevated ***,Ni-doping in Bi_(0.5)Sb_(1.5)Te_(3) also reduces kL which is attributed to the phonon scattering due to mass fluctuations and microstructural features such as grain boundary and strain field domain observed from HRTEM *** favourable condition leads to maximum ZT~1.38 at 433k for Bi_(0.5)Sb_(1.46)Ni_(0.04)Te_(3) and ZT_(avg)~1.1 between 300k and *** the calculated theoretical TE conversion device efficiency h of Bi_(0.5)Sb_(1.46)Ni_(0.04)Te3(η~5.5%)was achieved to be nearly twice than the efficiency of matrix Bi_(0.5)Sb_(1.5)Te3(h~3%).Experimental electronic transport is well corroborated with theoretically estimated DFT results.

关键词： Density functional theory Electronic transport Electron microscopy Bipolar thermal conductivity Thermoelectric performance and quality factor

URBAN STORMWATER MANGEMENT-AN MS4 SUCCESS STORY FOR WESTERN MICHIGAN UNIVERSITY

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Journal of Green Building 2012年第1期7卷 28-39页

作者： k.Brian Boyer Mark S.kieser Environmental Engineering Manager Kieser&Associates kieser&Associates LLC

Regulation of stormwater runoff is increasing throughout the United *** Environmental Protection Agency(EPA)and state agencies are beginning to move toward effluent and/or load limits for pollutants in *** costs for treating urban stormwater runoff,especially in highly-developed areas where retrofits are required,will only continue to increase.

关键词： urban stormwater nonpoint source MS4 TMDL total phosphorus stormwater BMP load allocation Stormwater NeutralTM water quality monitoring

Magnetic relaxation behavior of a spatially closed dysprosium(Ⅲ) phthalocyaninato double-decker complex

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Science China Chemistry 2012年第6期55卷 918-925,1178-1184页

作者： kATOH keiichi UMETSU kaori BREEDLOVE BRIAN k. YAMASHITA Masahiro Department of Chemistry Graduate School of Science Tohoku University 6-3 Aramaki-Aza-Aoba Aoba-ku Sendai Miyagi 980-8578 Japan

The SMM properties of the spatially closed Dy（Ⅲ） double-decker Pc complex Dy（obPc）2 （1）, which is equivalent to a pseudo dinuclear complex, are reported. Complex 1 crystallized with ethanol in the crystal lattice in the monoclinic space group P22/n and was isomorphous with Tb（obPc）2 （3）, which is arranged in a dimer structure along the b axis. The intermetallic Dy-Dy distance was determined to be 0.756 nm. ZMT versus T plots for 1 decreased with a decrease in T, which suggests the existence of an antiferromagnetic （AF） interaction between the Dy3＋ ions. The M-H curve for 1 at 1.8 k showed magnetic hysteresis. In ac susceptibility measurements on a powder sample of 1, which were dependent on the applied ac field, indicating that 1 is an single molecule magnet （SMM）, a maximum appeared at 22 k at an ac frequency 09 of 1488 Hz. The shape of the peaks dras- tically changed, and the peaks did not shift when an Hd~ large enough to suppress the quantum tunneling of the magnetization （QTM） was applied. The energy barrier （A/hc） was estimated to be 44 cm-1 with a pre-exponential factor （r0） of 1.6 × 10-5 s from an Arrhenius plot. Our results suggest that the SMM/magnetic properties of 1 significantly change in a dc magnetic field. These relaxation mechanisms are related to the energy gap of the ground state and to QTM.

关键词： single-molecule magnets dysprosium double-decker complex pseudo dinuclear complex magnetic relaxation process

Improvement of displacement error of rainfall and wind field forecast associated with landfalling tropical cyclone AMPHAN

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Tropical Cyclone Research and Review 2022年第3期11卷 146-162页

作者： S.D.kotal S.k.Bhattacharya India Meteorological Department Ministry of Earth Science Government of IndiaNew DelhiIndia

Spatial distribution of rainfall and wind speed forecast errors associated with landfalling tropical cyclones(TC)occur significantly due to incorrect location forecast by numerical *** major areas of errors are:(i)over-estimation over the model forecast locations and(ii)underestimation over the observed locations of the TCs.A modification method is proposed for real-time improvement of rainfall and wind field forecasts and demonstrated for the typical TC AMPHAN over the Bay of Bengal in *** proposed method to improve the model forecasts is a relocation method through shifting of model forecast locations of TC to the real-time official forecast locations of India Meteorological Department(IMD).The modification is applied to the forecasts obtained from the operational numerical model,the Global Forecast System(GFS)of *** of the proposed method shows considerable improvement of both the parameters over both the *** rainfall forecast errors due to displacement are found to have improved by 44.1%–69.8%and 72.1%–85.2%over the GFS forecast locations and over the observed locations respectively for the respective forecast lead times 48 h,72 h,and 96 ***,the wind speed forecasts have improved by 27.6%–56.0%and 63.7%–84.6%over the GFS forecast locations and over the observed locations respectively for the respective forecast lead times 60 h,72 h,and 84 *** results show that the proposed technique has capacity to provide improved spatial distributions of rainfall and wind speed forecasts associated with landfalling TCs and useful guidance to operational forecasters.

关键词： Tropical cyclone Track forecast Rainfall forecast Wind field Spatial distribution North Indian ocean

Implications of digital elevation models on habitat analysis of Golden Mahseer in the Upper Ganga Basin,India

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Water Biology and Security 2024年第4期3卷 44-54页

作者： J.P.Nale G.k.Pakhale Department of Civil Engineering Indian Institute of TechnologyDelhiIndia

Aquatic habitat analysis is crucial in determining the relationship between river flow and habitat availability for aquatic *** helps in identifying the environmental flow requirements of ***,conducting habitat analysis in Indian rivers is challenging because of the unavailability of reliable and high-resolution terrain *** address this challenge,a study was conducted to explore the possibilities of using Digital Elevation Models(DEMs)to extract required hydraulic data and to evaluate their *** extracted data were coupled with ecological data of a keystone fish species,namely Golden Mahseer(Tor putitora),to develop habitat analysis models for the Upper Ganga Basin(UGB)in *** study adopted a hierarchical three-step approach for evaluating the accuracy and performance of DEMs as surrogate data ***,cross sections at selected sites in the UGB were extracted from three different DEMs(SRTM,ASTER,and CARTOSAT)and evaluated against surveyed cross-section data with turning point tests and correlation *** data were then used to establish hydraulic and habitat analysis *** parameters(top width,flow cross-sectional area,hydraulic mean depth,and wetted perimeter)were evaluated using five error estimators to determine the accuracy and performance of hydraulic ***,the hydraulic parameters were coupled with ecological requirements to develop a habitat model for different life stages of Golden Mahseer,namely fingerling,juvenile,and adult *** found that the SRTM predictions were better than those of the other DEMs,indicating its suitability to replicate channel geometry with higher accuracy,thus better predicting hydraulic parameters at all flow *** habitat area estimation for adult Golden Mahseer,all the DEMs performed reasonably well(within±20%)within the flow range of 100 m3/s,which covers the low to average flow *** this flow range,ASTER and CARTOSAT resulted in conside

关键词： DEM Environmental flows(E-flows) Golden mahseer Habitat modelling Hydraulic modelling

Minimal conceptual models for tropical cyclone intensification

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Tropical Cyclone Research and Review 2022年第2期11卷 61-75页

作者： Michael T.Montgomery Roger k.Smith Department of Meteorology Naval Postgraduate SchoolMontereyCAUSA Meteorological Institute Ludwig-Maximilians UniversityMunichGermany

We examine a hierarchy of minimal conceptual models for tropical cyclone *** models are framed mostly in terms of axisymmetric balance *** the first set of models,the heating rate is prescribed in such a way to mimic a deep overturning circulation with convergence in the lower troposphere and divergence in the upper troposphere,characteristic of a region of deep moist *** the second set,the heating rate is related explicitly to the latent heat release of ascending air *** release of latent heat markedly reduces the local static stability of ascending air,raising two possibilities in the balance *** first possibility is that the effective static stability and the related discriminant in the Eliassen equation for the overturning circulation in saturated air,although small,remains positive so the Eliassen equation is globally *** second possibility,the more likely one during vortex intensification,is that the effective static stability in saturated air is negative and the Eliassen equation becomes locally *** models help to understand the differences between the early Ooyama models of 1968 and 1969,the Emanuel,1989 model,and the later Emanuel models of 1995,1997 and *** provide insight also into the popular explanation of the WISHE feedback mechanism for tropical cyclone *** implications for recent work are discussed.

关键词： Tropical cyclone intensification Conventional spin-up mechanism Minimal models Nonlinear boundary layer spin-up mechanism WISHE feedback Mechanism