Dictionary A chemical-shift reference is used to define the (CH3)4SI positions of the resonances in the spectrum in terms of parts-per-million, or ppm, of frequency It is a material which is often directly added to the

3. 1 Chemical shift When an atom is placed in a magnetic field B its electrons circulate about the direction of the applied magnetic field. This circulation causes a small magnetic field at the nucleus which opposes the externally applied field The magnetic field at the nucleus(the effective field) is therefore generally less than the applied field by a fraction THNMR

nature publishing group http://structbio.nature.com news and views Department of Biological Sciences. chem.276146-116200 Columbia University, New York, New York 6. Chen,.. Sharma, 5. Quiocho, F.A. Davidson. A.L. 15. Jones. P.M. George. A.M. FEMS Microbiol. Lett

NMR spectroscopy in structure-based drug design Gordon CK Roberts NMR methods for the study of motion in proteins continue Structure and dynamics of the binding site improve, and a n d complexes Methodological developments in NMR of macromolecules relevant to drug design

PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY ELSEVIER Progress in Nuclear Magnetic Resonance Spectroscopy 38 (2001) 325-360 www.elsevier.nl/locate/pnmrs NMR quantum computation J.A. Jonesa,b,* \Oxford Centre for Molecular Sciences. New Chemistry Laboratory South Parks Road, Oxford OXI 3QT. UK

6 The noe effect c Gerd Gemmecker, 1999 Nuclear OVERHAUSER Effect(NOE): resonance line intensity changes caused by dipolare cross- relaxation from neighbouring spins with perturbed energy level populations To understand the nature of the NOE, we have to look at a two-spin system I' and

2 Basis Principles of FT NMR C Gerd Gemmecker 1999 Nuclei in magnetic fields Atomic nuclei are composed of nucleons, i.e., protons and neutrons. Each of these particles shows a property named\spin\(behaving like an angular momentum) that adds up to the total spin of the

第一节植物的休眠与种子萌发 第二节植物的生长发育 第三节植物生长的相关性 第四节影响植物生长的环境因素及其调

第一节幼年期与花熟状态 第二节春花作用和成花诱导 第三节光周期与成花诱导 第四节营养条件与成花诱导 第五节植物激素与成花诱导 第六节花器官形成和性别表现 第七节草本与木本植物成花的比较与花期控制

第一节生长素类 第二节赤霉素类 第三节细胞分裂素类 第四节脱落酸 第五节乙烯 第六节植物激素间的相互关系