镧系金属化合物催化苯乙烯和双烯烃的共聚──苯乙烯和异戊二烯共聚合制备高顺式－1，4嵌段共聚物

采用稀土催化体系Ｎｄ（Ｆ_３ＣＯ_２）_３－ＢｒＣ_５Ｈ_（１１）－Ｒ_ｍＡｌＨ_（３－ｍ）（Ｎｄ－Ｂｒ－Ａｌ），以甲苯为溶剂，在５０℃恒温水浴中进行苯乙烯（Ｓｔ）和异戊二烯（Ｉｐ）共聚合。结果表明，由Ａｌ（Ｏｃｔ）－３组成的催化体系可制备以顺式－１，４结构为主的共聚物；在后者组成的催化体系中，当Ａｌ／Ｎｄ＝５（摩尔比，下同），Ｂｒ／Ｎｄ＝５时，聚合活性最高。经ＩＲ，ＮＭＲ检测表征了共聚物的微观结构。同时，用π－烯丙基型配位机理和返扣配位机理对实验结果进行了定性解释。     

Bioeffects of Rare Earth Complex on Rats Studied by NMR and ICP-MS Spectroscopy

Thedevelopmentofhigh fieldNMRspectrome terswithincreasedsensitivity,resolution,dynamic rangeandimprovedcomputingcapabilitieshasmade itpossibletouseNMRtechniqueforrapidmulticom ponentanalysisoflowMWcompoundsinbiofluids inordertoassessthetoxicologicaleffe…     

Investigation on Acute Biochemical Effects of Ce（NO3 ）3 on Liver and Kidney Tissues by MAS 1H NMR Spectroscopic-Based Metabonomic Approach

High resolution1Hmagicanglespinning(MAS)NMRspectroscopyisincreasinglybeingusedasause fultechniqueforinvestigatingthemetabolicstateof variousintacttissuesintheareasofdrugtoxicity[1,2]anddiseasediagnosis[3,4].Biologicaltissuesaresemi solidheterogeneouscomplexcontainingspecieswitha widerangeofmolecularweightssuchasproteins,lip ids,andlow molecularweightmetabolites[5].1HNMR spectraoftissuesufferfrommajorline broadeningcon tributionswhenacquiredbyconventionalsolution state NMRspectroscopybecau…     

Biochemical effects of gadolinium chloride in rats liver and kidney studied by ^1H NMR metabolomics

The biochemical effects of gadolinium chloride were studied using high-resolution IH nuclear magnetic resonance (NMR) spec-troscopy to investigate the biochemical composition of tissue (liver and kidney) aqueous extracts obtained from control and gadolinium chlo-ride (GdCl3) (10 and 50 mg/kg body weight, intraperitoneal injection, i.p.) treated rats. Tissue samples were collected at 48, 96 and 168 h p.d. after exposure to GdCl3, and extracted using methanol/chloroform solvent system. 1H NMR spectra of tissue extracts were analyzed by pat-tern recognition using principal components analysis. The liver damages caused by GdCl3 were characterized by increased succinate and de-creased glycogen level and elevated lactate, alanine and betaine concentration in liver. Furthermore, the increase of creatine and lactate, and decrease of glutamate, alanine, phosphocholine, glycophosphocholine (GPC), betaine, myo-inositoi and trimethylamine N-oxide (TMAO)levels in kidney illustrated kidney disturbance induced by GdCl3.     

The ~(13)C-NMR Study of the Conformation of L-Arginine in Aqueous Solution by Lanthanide Probes

The heavy lanthanide ions(Dy,Ho,Er,Tm and Yb)were used to probe the conformation of L-arginine inaqueous solution.The results showed that the contact contribution to the observed~(13)C paramagnetic shift is verysmall for nuclei four or more bonds away from the bound lanthanide ion and it is significant for those in closeproximity to the lanthanide ion.The overall conformation of L-arginine was established by fitting the calculatedgeometric factors for the corresponding experimental data.In the lanthanide-L-arginine complex,the wholebackbone of the ligand is located outsite the zero-dipolar shift cone of the lanthanide ion with the carboxyl groupselectively coordinated to the metal.The calculated RE-O distance is 0.21 nm for the bidentate coordinationmode and the ligand is in an extended conformation in the solution with the molecular backbone corresponding tothe trans form.     

NMR Studies of η~3-Allyl Rare Earth Metal Complexes

ＮＭＲＳｔｕｄｉｅｓｏｆη~３－ＡｌｌｙｌＲａｒｅＥａｒｔｈＭｅｔａｌＣｏｍｐｌｅｘｅｓＬｉＦｅｎｇ－Ｆｕ；（李凤富）；ＪｉｎＹｉｎｇ－Ｔａｉ；（金鹰泰）；ＲｅｎＪｉ－Ｍｉｎ；（任吉民）；ＳｕｎＹｕ－Ｆａｎｇ；（孙玉芳）；ＰｅｉＦｅｎｇ－Ｋｕｉ；（裴?..     

Comparison of Biochemical Effects Induced by Changle between Male and Female Rats Using NMR and ICP-MS Techniques

NMRspectroscopyofbiofluidhasbroughtnew chemistryintolifescienceandclinicalmedicine,and NMRspectroscopy basedapproachhasbeensuccess fullyappliedtothestudiesofbiochemicaleffectsand inborndiseaseswiththeadventofhighfieldNMR spectrometers[1].Inrecentyears,highresolutionNMRhasbeenusedtotherapidmulticomponentanal ysisoflowmolecularweightcompoundsinbiofluid,includingurine,bile,cerebrospinalfluid,saliva,milkandsynovialfluidforclinicaldiagnosisofinborn diseasesandinvestigationofbiochemicaleffectsof…     

用数字平均法提高NMR信噪比的计算机程序问题

对弱信号进行同步累加是提高信噪比的一种手段。本文介绍了自制的100兆脉冲付里叶变换核磁共振(PFT—NMR)波谱仅用数字同步累加方法提高信号灵敏度的原理、装置及程序。