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92 个结果
  • 简介:Samplesofpolyphenylsilsisquioxane(PPSQ)usingCaF2orMgF2asthemaincatalystshadbeenpreparedunderdifferentpolymerizationconditions.TheresultsweretreatedonanorthogonaldesignL9(34).Allweight-averagemolecularweights(MW)ofPPSQhadbeenmeasuredbygelpermeationchromatography(GPC).Effectsofpolymerizationconditionsincludingreactiontemperature,compositionofthedualcatalysts(CaF2orMgF2andDCC),mixtureofsolventsandreactiontimeonMWofPPSQhavebeendiscussed.ThequantityofthecatalystsisthemostimportantfactorthataffectsMWofPPSQ.Reactiontemperatureisthesecondimportantfactor.AppropriatepolymerizationconditionhasbeenestablishedtogetPPSQwithhighMW.

  • 标签: Polyphenylsilsisquioxane POLYMERIZATION CONDITIONS MOLECULAR WEIGHT
  • 简介:Thispaperproposesanovelexemplar-basedmethodforreducingnoiseincomputedtomography(CT)images.Intheproposedmethod,denoisingisperformedoneachblockwiththehelpofagivendatabaseofstandardimageblocks.Foreachnoisyblock,itsdenoisedversionisthebestsparsepositivelinearcombinationoftheblocksinthedatabase.Weformulatetheproblemasaconstrainedoptimizationproblemsuchthatthesolutionisthedenoisedblock.Experimentalresultsdemonstratethegoodperformanceoftheproposedmethodovercurrentstate-of-the-artdenoisingmethods,intermsofbothobjectiveandsubjectiveevaluations.

  • 标签: 图像去噪 CT 权重法 计算机断层扫描 约束最优化问题 降低噪声
  • 简介:Anumericalsolutionoftheweightfunctionforatwo-electrodeelectromagneticflowmeterwasproposed.Thesolutionwasobtainedbyusingthefiniteelementmethodbasedonthebasicequationofatraditionaltwo-electrodeelectromagneticflowmeter.Thetwo-dimensionaldistributionoftheweightfunctionoftheelectromagneticflowmeterobtainedwasverifiedbytheanalyticalsolution.Three-dimensionaldistributionoftheweightfunctionwasalsopresentedinthepaper.Itcanbeemployedtoanalyzethesensitivityandlinearityoftheelectromagneticflowmeterwithnon-uniformmagneticfield,andeventoassistthedesignoftheexcitationcoilpair.

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  • 简介:AbstractBackground:Gestational weight gain (GWG) is associated with the risk of gestational diabetes mellitus (GDM). However, the effect of weight gain in different trimesters on the risk of GDM is unclear. This study aimed to evaluate the effect of GWG on GDM during different trimesters.Methods:A birth cohort study was conducted from 2017 to 2020 in Shenzhen, China. In total, 51,205 participants were included comprising two models (early pregnancy model and middle pregnancy model). Gestational weight (kg) was measured at each prenatal clinical visit using a standardized weight scale. Logistic regression analysis was used to assess the risk of GDM. Interaction analysis and mediation effect analysis were performed in the middle pregnancy model.Results:In the early pregnancy model, the risk of GDM was 0.858 times lower (95% confidence interval [CI]: 0.786, 0.937) with insufficient GWG (iGWG) and 1.201 times higher (95% CI: 1.097, 1.316) with excessive GWG after adjustment. In the middle pregnancy model, the risk of GDM associated with iGWG increased 1.595 times (95% CI: 1.418, 1.794) after adjustment; for excessive GWG, no significant difference was found (P = 0.223). Interaction analysis showed no interaction between GWG in early pregnancy (GWG-E) and GWG in middle pregnancy (GWG-M) (F = 1.268; P = 0.280). The mediation effect analysis indicated that GWG-M plays a partial mediating role, with an effect proportion of 14.9%.Conclusions:eGWG-E and iGWG-M are associated with an increased risk of GDM. Strict control of weight gain in early pregnancy is needed, and sufficient nutrition should be provided in middle pregnancy.

  • 标签: Gestational diabetes mellitus Gestational weight gain Early pregnancy Middle pregnancy
  • 简介:Thispaperisdevotedtodeterminingthestructuresandpropertiesofone-Leeweightcodesandtwo-LeeweightprojectivecodesCk1,k2,k3overpIF+vIFpwithtypep2k1pk2pk3.Theauthorsintroduceadistance-preservingGraymapfrom(IFp+vIFp)nto2np.BytheGraymap,theauthorsconstructafamilyofoptimalone-Hammingweightp-arylinearcodesfromone-LeeweightcodesoverIFp+vIFp,whichattainthePlotkinboundandtheGriesmerbound.Theauthorsalsoobtainaclassofoptimalp-arylinearcodesfromtwo-LeeweightprojectivecodesoverIFp+vIFp,whichmeettheGriesmerbound.

  • 标签: 汉明重量 IFP Plotkin界 P码 灰度图 线性码
  • 简介:Light-weightcompositepanelsweremanufacturedusingkenafcoreparticlesascorematerialandkenafbastfiber-wovensheetsastopandbottomsurfaces.Methylenediphenyldiisocyanate(MDI)resinwasusedastheadhesivewiththeresincontentof4%forcoreparticlesand50g/m2forbastfiber-wovensheets.Thetargetboarddensitiesweresetat0.35,0.45and0.55g/cm3.ThecompositepanelswereevaluatedwithJapaneseIndustrialStandardforParticleboards(JISA5908-2003).Theresultsshowthatthecompositepanelhashighmodulusofruptureandinternalbondingstrength.Thepropertiesof0.45g/cm3densitycompositepanelare:MOR20.4MPa,MOE1.94MPa,IB0.36MPa,WA142%,TS21%.Kenafisagoodrawmaterialformakinglight-weightcompositepanels.

  • 标签: 洋麻 木心材料 树皮纤维 复合板
  • 简介:Anaccuratecracksurfaceopeningdisplacementformulaforedgecracksinfinitebodieshasbeenderived,andwassubsequentlyusedtodevelopwide-rangeclosed-formweightfunctionsforedgecracks.Theanalyticalweightfunctionisgeneralandcanbeeasilyusedtodetermineaccuratestressintensityfactorsandcracksurfaceopeningdisplacementsforarbitrarilyloadededgecrackswithhighefficiency.Exampleshavebeengivenforproblemsofedgecrack(s)withanumberoftypicalloadconditionsforillustration.

  • 标签: CRACK weight function stress INTENSITY factor
  • 简介:ThehotloaddeformationtestsoffourkindsofinsulatingfireclaybrickswerecarriedoutusingahightemperaturecreepfurnacefromSinosteelLuoyangInstituteofRefractoriesResearchCo.,Ltd.Thetestingloadwasfixedat0.069MPaandthetotaltestingtimewaswithin6hincludingtheholdingtimeof1.5h.Thehotloaddeformationprocessofinsulatingfireclaybrickscanbedividedintothreesteps:(1)expansionstepfromroomtemperaturetoRULTmax;(2)quickshrinkagestepbetweenRULTmaxandTtest;3)relativelyslowshrinkagestepduringholdingprocess.Thedeformationrateatthebeginningofholdingprocess(D0h)shouldbecontrolledwithin±0.1%.ThehotloaddeformationtestingtemperatureofinsulatingfireclaybrickswasoptimizedasthevalueofRULTmaxplus220℃.

  • 标签: 变形温度 热负荷 粘土砖 绝缘 重量轻 测试时间
  • 简介:Regularizationmethodisaneffectivemethodforsolvingill-posedequation.Inthispapertheunbiasedestimationformulaofunitweightstandarddeviationintheregularizationsolutionisderivedandtheformulaisverifiedwithnumericalcaseof1000sampledatabyuseofthetypicalill-posedequation,i.e.theFredholmintegrationequationofthefirstkind.

  • 标签: 无偏估计规则 规则化解决方案 个体重量规格分离 测量平差
  • 简介:ToexploretheactionmechanismofmoxibustiononZusanli(ST36)intreatingmalnutrition.MethodsInfantileSDratsweredividedintonormalgroup,modelgroup,comparisongroupandtreatmentgroup.Ganjimodelsofratweremadebyfeedinghighfatandhighcaloriefood.Thentheyweretreatedwithmoxibustionon“Housali”.ResultsAfterthemodelsbeingmade,theappetite,weight,GASandMTLweredecreased.Aftertwoperiodsoftreatment,theywereallincreasedandwerenearlyturnedtobenormallevel.ConclusionMoxibustiononZusanli(ST36)canimprovetheappetite,weight,GASandMTLinGanjimodelsofratandregulatetheirdigestivefunction.

  • 标签: 针灸 艾灸 GAS MTL 动物模型
  • 简介:5-10mgL-1的申请流水可溶到沟灌水的离子的polyacrylamide(PAM)实质地在流动进展期间减少沉积损失和增加网络渗入。我们假设了那PAM_s大音阶的第五音vated分子的符合构造影响它的灌溉管理功效。学习被进行在Kimberly,爱达荷,在Portneuf粉砂壤土(Durinodic旱生植物的Haplocalcids)上;在灌溉沟的豆子下面(Phaseolus粗俗)在1.5%斜坡。有对比分子量的Polyacrylamides(一离子:4-7,12-15和14-17MDa,即Mgmol-1),费用类型(中立,一离子,猫离子),并且费用密度(8,19,35摩尔%)在二研究被测试。流入率为留下的集合在沟进展,和15Lmin-1期间是23Lmin-1。Anionic和中立PAM象猫一样两次有效为在新沟控制沉积损失的离子的PAM。为全面土壤损失控制的有效性的顺序是:一离子>中立>猫与增加增加的离子的PAM,和功效控告密度或分子量。当PAM处理分子量从17~4MDa被减少时,网沟渗入增加了14~19%。一般趋势建议了离子、中立的PAM生产了的那中等、高的费用密度渗入的最大的增加与控制相比。与未经治疗的沟相比,中立PAM给了最大的季节长的网渗入获得(5%);当控告时,PAM趋于在新沟上在季节早增加网渗入,但是减少在季节以后的灌溉重复的沟上的渗入。

  • 标签: POLYMER CHARGE Molecular WEIGHT effect Soil
  • 简介:Anewkindofbinaryhydrogelscomposedofpoly(dimethylaminoethylmethacrylate)(PDMAEMA)andpoly(ethyleneoxide)(PEO)withvaryingweightaveragemolecularweights((?)_w=5×10~4,1×10~5and2.5×10~6)werepreparedbyγ-irradiationtechnology.ThepropertiesofPDMAEMA/PEOhydrogelsobtainedwereevaluatedintermsofgelfraction,gelstrength,thermalcharacterizationandswellingbehavior.ThegelstrengthandswellingdegreeofthehydrogelscouldbeimprovedobviouslyafteraddingPEOintothePDMAEMAsystem,whilethedegreeofimprovementdecreasedwithincreasing(?)_wofPEO.ThetemperaturesensitivityofPDMAEMA/PEOwasretainedonlyinthesamplewithPEOof(?)_w=5×10~4,andthepHsensitivitywasretainedinsampleswithPEOof(?)_w=5×10~4and1×10~5.WhenDMAEMA/PEOmixturescontainingPEOof(?)_w=5×10~4wereirradiated,themainreactioncouldbethecross-linkingofDMAEMA,andthelinearPEOmolecularchainscouldpenetrateintothecross-linkednetworkofPDMAEMA.Withincreasing(?)_wofPEO,somesidereactionswereinduced,suchasgraftingofDMAEMAontoPEOmolecules,thescissionorcross-linkingofPEO.

  • 标签: 聚乙撑氧 PDMAEMA/PEO水凝胶 聚(二甲基氨基乙烷基异丁烯酸酯)分子量 二元水凝胶
  • 简介:在这份报纸,为非退化的本地最小加权的Ginzburg四轮马车方程的重新使正常化的精力削尖的任何给定的d,一个人能发现答案到其旋涡趋于到这些d点的Ginzburg四轮马车方程,这被证明。这向在Ginzburg四轮马车方程的一个类的解决方案之间的连接提供重新使正常化的精力的重量和minimizers。

  • 标签: 重正规化能 加权Ginzburg-Landau方程 极小化
  • 简介:在这份报纸,作者得到Coifman类型为multilinear的珍视向量的概括整流器的加权的估计和弱加权的LlogL估计有A的部分积分。而且,两个都,部分积分和弱加权的LlogL为部分积分也是的珍视向量的multilinear估计的珍视向量的multilinear的固定获得了。

  • 标签: 多线性分数次积分 重量估计 向量值 交换子 加权估计 分数阶积分
  • 简介:当为林地生产提起机械化层次时,林地机械的合适的匹配是重要的。在匹配的过程,林地机械不必仅仅为解决问题的专家知识,而且改进方法。我由在一个分析、层次的过程计算各种各样的林地机器的量的参数的类似建议基于盒子的推理的联合(CBR)(RBR)并且基于规则的推理。我计算了在森林工业过去常启用更好的选择的机械的类似并且设备匹配。我建议基于单个参数重量在申请的进程在被修改的偏差的广场的和调整方法的重量值。在系统设计的过程期间,我提出了一个设计方法知识库并且产生了推理的一张动态网集成森林工业的过程的框架机械选择和重量值调整。这启用推理效率的完全的系统和改进的范围的扩大。我用一个实际例子表明这个方法的有效性和有实行可能。

  • 标签: 林业机械 权值调整 匹配过程 基于规则的推理 相似性分析 基于案例推理