正方形ABCD中,O是AC与BD的交点,∠DAC的平分线AP交CD于P,∠BDC的角平分线DQ交AC于Q,求BD\CD=AP\BQ

正方形ABCD中,O是AC与BD的交点,∠DAC的平分线AP交CD于P,∠BDC的角平分线DQ交AC于Q,求BD\CD=AP\BQ
正方形ABCD中,O是AC与BD的交点,∠DAC的平分线AP交CD于P,∠BDC的角平分线DQ交AC于Q,求BD\CD=AP\BQ

正方形ABCD中,O是AC与BD的交点,∠DAC的平分线AP交CD于P,∠BDC的角平分线DQ交AC于Q,求BD\CD=AP\BQ
证明:延长DQ交BC于M,由题意及正方形的性质可得:Q为△BDC
中角平分线DM和CO交点⇒Q为△CDB内心⇒BQ平分∠DBC
⇒∠QBO=∠CDM=45°/2
∠DCM=∠BOQ=RT∠
△DCM∼△BOQ⇒DM/BQ=CM/OQ
∠CQM=∠CMQ=45+22.5=67.5°
⇒CQ=CM
易知△DAC≅△CDB⇒AP=DM(全等三角形的对应线段相等)
⇒CQ/QO=AP/BQ
BD/CD=CD/DO=√(2)/1
DQ平分∠ODC⇒CD/OD=CQ/QO
⇒BD/CD=AP/BQ

NMR Characterization of epoxy resin


Construction, reference E51 epoxy resin, AG 80 epoxy resin of a hydrogen spectrum, can be confirmed, d2.6 and 2.8 two peaks for the H-1 on the two...

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NMR Characterization of epoxy resin


Construction, reference E51 epoxy resin, AG 80 epoxy resin of a hydrogen spectrum, can be confirmed, d2.6 and 2.8 two peaks for the H-1 on the two methylene hydrogen; d3.9 and d4.5 for the H-3 on the two methylene hydrogen; Clearly, in the high field peaks at d2.3 should be on a six-membered ring methylene hydrogen (H a 6), according to this hydrogen coupling effect, may be initially identified the peak of 3.0 on a six-membered ring with the ester groups on adjacent carbon hydrogen (H5); and in two peaks at 3.2,3.3, compared with epoxy on The methylene hydrogen from the structure point of view, six epoxy ring methylene hydrogen (H7j should be higher than the right end of epoxy methylene hydrogen (H2) in the higher courts, ie 2.4 The peak for the six-ring epoxy methylene hydrogen (H a 7). The peaks identified in Table 1. from TDE 85 epoxy resin for a peaks at the carbonyl carbon, 25.1 at the peak of six-membered ring on the methylene carbon,mbt chaussures paris, according to its} IETcOR spectrum (Figure 12), I identified all the other carbon peaks (see Table 2), and confirmed the NMR identified in the results of each peak. From the above one on the E 51,, rI) E a 85, AG 8O epoxy resin of a H, c the identification of spectral peaks can be seen, epoxy group 0 - CHr-CH -CH: 32160140I20loo80604020,christian louboutin boutique, ppm circle 11TDE an epoxy resin 85 11Cspo2t ~ llm0fTDE a 85epoxyresi ~, 2 / it. ~ LIL-7654321OF1/ppm Chart】 2TDE-85 epoxy resin HETCOR thumb potential Fig. 12HETCORspectrumofTDE a 85epoxyr, the one and two of H, C chemical shifts in different epoxy little difference, and three of H, result, when the larger electronegativity of oxygen atoms is connected, H, H, l, Ji g-bit,abercrombie paris ouverture, and so on. IR spectra of epoxy resin measured values ??of roll _J] stoichiometry, 1995.4 (1): Shí. [nail JOURNAL OF HARBIN. Ji grams bit. ZHANG Shu-fang. and so on. glass annulus epoxy resin pre-process quality control method of Section _J]. Composite Materials. i995.13 (1): 21 [4] ColeKc.R. 0mtemperatnreagingofNarmco5208carbon-e-poxypreprag} partIphysi ~ hemicalcharacteri ~ tionLJPo / ymerComic, sites.1989, 10 (3): 150 - [52 Wang by cabinet. polyphonic material tree nitrile substrate rR of party Ru: J: Glass actinium, composite materials,ralph lauren pas cher, 1990f5): 25:6: Li Zhili, Liu Tsang Ying. Qiang Yun, et al. King phenolic epoxy matrix-assisted photolysis of warm Ionization Mass Spectrometry: J] Journal of Materials Research .1997,11 (4): 419. [7] Li Zhili. Liu Ying pepper. Zhang Yun students, and other types of E-type epoxy .5 resin matrix-assisted laser desorption Ionization Mass Spectrometry J. Materials Science Research .1997.14 (4): 14 [8] KingJJHPLCEvaluation0fMY720 [c] 27thSAMPE.1982.163. [9] NoelnH white bpertorrn ~ ocesix-exclusioncbromatographyoffiber-reirdorcedccgnnic ~ trixcomposit ~ [Mun. JofChromagography ? 1987,408 = 129. [10] NoelI1High-speed iv sph & seliquidchromatographywith3L cricket packingforanalysisotfiber-reinforcedepoxycomposites {or More articles related to topics：


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