检索结果-南通市图书馆

Scrutinise the variations of glaciers and their climatic attributions in the Sanjiangyuan National Park during 1969-2018

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2022年第4期13卷 531-539页

作者： Lin WANG Yan-Qun BI Fei-Teng WANG Chang-Bin BAI Jing MING State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Beacon Science&Consulting Malvern SA 5061Australia

Since 2020,the first national park of China,the Sanjiangyuan National Park(Park)has been put into operation in *** Park is one of the most vulnerable regions to the rapid climate change in the Tibetan *** have not been any investigations into the current status of the glacier resources in the Park so *** study reported the first summary of the glaciers in the Park at present and their variations since the *** data used here come from the two Chinese Glacier Inventories finished during 1969-1970 and 2006-2010,respectively,and the remote-sensing images during 1985-1990,1995-2000 and *** total glacier area in the Park is 772 km^(2)to our best estimate,much less than 2342 km^(2)reported in the first Chinese Glacier Inventory published in *** shrinkage rate of the glaciers in the Yangtze River Park(a sub-park)had slowed from-0.37%per year during the 1970s to-0.09%per year during 2002-2012 in area,while that in the Lancang River Park had sped up from-0.34%per year during 1968-2000 to-0.67%per year during *** are no glaciers in the Yellow River Park(a sub-park).The change in the glaciers was related to the regional relatively rapidly warming and insufficient mass supply from *** geographic features of the glaciers in the Yangtze and Lancang Parks also lead to their different change extents,most of which happened at 5500 m *** below.

关键词： Sanjiangyuan National Park Tibetan Plateau Glaciers Remote sensing Climate change Geographic features

STUDIES ON MOLECULAR WEIGHT DISTRIBUTION OF CARBON FIBER POLYMER PRECURSORS SYNTHESIZED USING MIXED SOLVENTS

维普期刊数据库评论

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 Polymer Science 2012年第5期30卷 664-673页

作者： G.Santhana Krishnan A.Burkanudeen N.Murali Hemant Phadnis Materials Science Division CSIRNational Aerospace LaboratoriesBangalore-560017India Post Graduate and Research Department of Chemistry Jamal Mohammed CollegeBharathidasan UniversityTiruchirappalliIndia malvern Application Laboratory Naimex HouseBangalore-560045India

The molecular weight distributions were estimated for carbon fiber polymer precursors such as poly（acrylonitrile-co-itaconic acid） synthesized by semi batch solution polymerization in mixed solvents media with the azonitrile compounds as initiator under the different ratios of solvent and non solvent from 0.75 to 2.5 in weight. The copolymer was characterized by using Fourier transform infrared spectroscopy （FTIR） and nuclear magnetic resonance （1H-NMR） analyses. The molecular weight distributions were evaluated by Mv/Mn ratios estimated from viscosity and osmotic measurements, and Mw/Mn estimated from size exclusion chromatography. The molecular weight distributions of these polymers as determined from M, JMn and Mw/Mn are 2.9 to 3,2 and 2.0 to 2.5 respectively. The molecular distributions were close to a narrow distribution of 2.0 when the solvent/non-solvent ratio was varied between 1.4 and 2.0. Intrinsic viscosity [η] as a function of molecular weight of poly（acrylonitrile-co-itaconic acid） was evaluated by means of low angle laser light scattering with size exclusion chromatography （SEC-LALLS） and viscometry with SEC （SEC-VISCO）. The relationship between [η] and Mw for poly（acrylonitrile-co-itaconic acid） in DMF at 50℃ was [q] = 1.1×10-5 Mw0.79, where [η] is obtained in dL/g.

关键词： Molecular weight distribution Size exclusion chromatography Osmometry Viscometry Polyacrylonitrilecopolyrner.

Thermodynamics of clayedrug complex dispersions: Isothermal titration calorimetry and high-performance liquid chromatography

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2020年第1期10卷 78-85页

作者： Ana-Maria Totea Juan Sabin Irina Dorin Karl Hemming Peter R.Laity Barbara R.Conway Laura Waters Kofi Asare-Addo School of Applied Sciences Department of PharmacyUniversity of HuddersfieldQueensgateHuddersfieldHD13DHUK AFFINImeter Edificio EmprendiaCampus VidaSantiago de CompostelaSpain malvern Panalytical Ltd. MalvernUK School of Applied Sciences Department of ChemistryUniversity of HuddersfieldQueensgateHuddersfieldHD13DHUK Department of Materials Science and Engineering University of SheffieldSir Robert Hadfield BuildingMappin StreetSheffieldS13JDUK

An understanding of the thermodynamics of the complexation process utilized in sustaining drug release in clay matrices is of great *** characterisation techniques as well as isothermal calorimetry were utilized in investigating the adsorption process of a model cationic drug(diltiazem hydrochloride,DIL)onto a pharmaceutical clay system(magnesium aluminium silicate,MAS).X-ray powder diffraction(XRPD),attenuated total reflectance Fourier transform infrared spectroscopy(ATRFTIR)and optical microscopy confirmed the successful formation of the DIL-MAS *** quantification from the complexes demonstrated variable behaviour in the differing media used with DIL degrading to desacetyl diltiazem hydrochloride(DC-DIL)in the 2 M HCl *** also,the authors report for the first time two binding processes that occurred for DIL and MAS.A competitor binding model was thus proposed and the thermodynamics obtained suggested their binding processes to be enthalpy driven and entropically *** information is of great importance for a formulator as care and consideration should be given with appropriate media selection as well as the nature of binding in complexes.

关键词： Clay-drug complex dispersions Magnesium aluminium silicate Diltiazem hydrochloride Isothermal titration calorimetry High performance liquid chromatography

Characterizing diseases using genetic and clinical variables:A data analytics approach

在线全文

学校读者我要写书评

暂无评论

Quantitative Biology 2024年第3期12卷 271-285页

作者： Madhuri Gollapalli Harsh Anand Satish Mahadevan Srinivasan Engineering Department Penn State Great ValleyMalvernPennsylvaniaUSA Department of Systems and Information Engineering School of Engineering and Applied ScienceUniversity of VirginiaCharlottesvilleVirginiaUSA

Predictive analytics is crucial in precision medicine for personalized patient *** aid in precision medicine,this study identifies a subset of genetic and clinical variables that can serve as predictors for classifying diseased tissues/disease *** achieve this,experiments were performed on diseased tissues obtained from the L1000 dataset to assess differences in the functionality and predictive capabilities of genetic and clinical *** this study,the k-means technique was used for clustering the diseased tissue types,and the multinomial logistic regression(MLR)technique was applied for classifying the diseased tissue *** reduction techniques including principal component analysis and Boruta are used extensively to reduce the dimensionality of genetic and clinical *** results showed that landmark genes performed slightly better in clustering diseased tissue types compared to any random set of 978 non-landmark genes,and the difference is statistically ***,it was evident that both clinical and genetic variables were important in predicting the diseased tissue *** top three clinical predictors for predicting diseased tissue types were identified as morphology,gender,and age of ***,this study explored the possibility of using the latent representations of the clusters of landmark and non-landmark genes as predictors for an MLR *** classification models built using MLR revealed that landmark genes can serve as a subset of genetic variables and/or as a proxy for clinical *** study concludes that combining predictive analytics with dimensionality reduction effectively identifies key predictors in precision medicine,enhancing diagnostic accuracy.

关键词： clustering k-means L1000 dataset analysis landmark genes multinomial logistic regression non-landmark genes principal component analysis tissue classification

Growth trends and environmental drivers of major tree species of the northern hardwood forest of eastern North America

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2023年第1期34卷 37-50页

作者： Rebecca L.Stern Paul G.Schaberg Shelly A.Rayback Christopher F.Hansen Paula F.Murakami Gary J.Hawley Rubenstein School of Environment and Natural Resources The University of VermontBurlingtonVT 05405USA ERM MalvernPA 19355USA Forest Service United States Department of AgricultureNorthern Research StationBurlingtonVT 05405USA Department of Geography The University of VermontBurlingtonVT 05405USA

The future health and productivity of tree species in the northern hardwood forest of eastern North America are uncertain considering changes in climate and pollution loading *** better understand the trajectory of the northern hardwood forest,we studied the growth of three tree species emblematic of it:sugar maple(Acer saccharum Marsh),American beech(Fagus grandifolia Ehrh.),and yellow birch(Betula alleghaniensis Britton),plus a fourth species,red maple(Acer rubrum L.),whose abundance has increased in the *** also analyzed the link between growth and several factors for690 trees in 45 plots throughout Vermont,USA:tree age and size,site elevation,and climate and acid deposition *** their chronologies(1945-2014),all four species exhibited increasing growth followed by plateaued growth indicative of a maturing *** all species,summer moisture was positively correlated with growth,summer temperature was negatively associated with growth,and winter moisture or snow were positively correlated with *** last association was expected for sugar ***,our data suggest that winter snowpack may be more broadly relevant in sustaining tree growth in a region where snow has historically insulated the soil from freezing that can damage roots and lead to reduced aboveground *** of pollution deposition were also correlated with growth for all species except American beech—a species with documented tolerance to pollutant *** the four species studied,red maple had the fewest associations with environmental variables,which suggests that it may be less susceptible to growth reductions as the climate changes.

关键词： Climate change Sugar maple Yellow birch American beech Red maple

在线全文

学校读者我要写书评

暂无评论

塑料复合材料在高温下的磨损

摩擦学学报 1988年第2期 129-132页

作者： M.P.Wolverton,J.E.Theberge,K.L.McCadden,张光跃 LNP Corp malvern Pa LNP Corp malvern Pa LNP Corp malvern Pa

现有塑料复合材料的摩擦、磨损数据通常仅适合于常温条件。最近的一些研究扩充了这些材料摩擦学性能的基本数据,使其适用温度达到260℃。由于金属的性能及成本方面的限制,热塑性材料已在许多齿轮和轴承的应用中取而代之。热塑性材料具... 详细信息

现有塑料复合材料的摩擦、磨损数据通常仅适合于常温条件。最近的一些研究扩充了这些材料摩擦学性能的基本数据,使其适用温度达到260℃。由于金属的性能及成本方面的限制,热塑性材料已在许多齿轮和轴承的应用中取而代之。热塑性材料具有抗冲击、吸震、能耗低、噪声小以及不常或不需要维修等优点。此外,再加上纤维增强和润滑填料,可使复合材料的性能具备强度高、承载能力强、摩擦小、尺寸稳定性好及使用寿命长等一些优点。

关键词：复合材料极限高温下纤维增强