2022/3/22
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
❖ 1946年， Purcell和 Bloch观察到核 磁共振现象。 于1952年获得 诺贝尔物理奖
2022/3/22
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
能级分布与弛豫过程
不同能级上分布的核数目可由Boltzmann 定律计算：
N N ij ex E p ik E T j ex k p E T ex h k p T
磁场强度2.3488 T；25C；1H 的共振频率与分配比：
共 振 2 频 B 02 .6 率 2 8 1 3 8. 0 2 2 .3 44 18 .0M 8 0 Hz
2022/3/22
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
质量数（a）原子序数（Z）自旋量子（I）
例子
奇数 偶数
奇或偶 偶数
1 , 3 , 5 222
0
I
1 2
,1H
1
,
13C6 ,19F9 ,15N 7
I
3 2
,11B5
,35

12C6 ,16O8 ,32S16
偶数
奇数
1，2，3…… I 1,2H1,14N 7 , I 3,10B5
一.基本原理
1．原子核的自旋:atomic nuclear spin
原子核和电子一样, 存在自旋.从而有自旋角 动量(ρ)和磁矩μ
如果放在外磁场中,
旋进轨道
自旋轴 自旋的质子
H0
2022/3/22
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
N N ij ex 6 .p 6 1 .3 2 1 8 6 3 0 0 1 41 6 2 0.0 3 0 6 2 0 0 1 960 8 J J K s 1 s K 1 0 .99998
两能级上核数目差：1.610-5；
弛豫(relaxtion)——高能态的核以非辐射的方式回到低能态。 饱和(saturated)——低能态的核等于高能态的核。
H '
H '
取 向 。
2022/3/22
一 致 H 0相 反
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
1945-1951年间，化学位移和自旋偶合的发现， NMR技术的化学应用。 1953年 世界上第一台商品化NMR谱仪. 1964年 世界上第一台超导磁场的NMR谱仪 1971年世界上第一台脉冲傅立叶变换NMR谱仪
2022/3/22
•1976年R.R.Ernst发表了二维核磁共振的理论 Thispaper mainlyintroducesthe designof anintelligent temperaturecontrolsystemwhichrealizes thefunctionof temperaturemeasurementandcontrolbyusingsingle busdigitaltemperature sensor DS18B20 andsingle chipmicrocomputer.The corecomponentsofthe systemareAT89C51microcontroller andDS18B20temperature sensor. 和实验的文章。获得1991年诺贝尔化学奖
每一种取向都对映一个能级状态，有一个ms 。如： 1H核：标记ms为－1/2 和 +1/2
高 能 态
H'
ms=_1/2
常 数 ) E=hν H0
外场
低 能 态
H'
ms=+1/2
2022/3/22
This paper mainly introduces the design of an intelligent temperature control sy stem which realizes the function of temperature measurement and control by using single bus digital temperature sensor DS18B20 and single chip microcomputer. The core components of the sy stem are AT89C51 microcontroller and DS18B20 temperature sensor.
2.自旋核在外加磁场中的取向(旋转方向)
取向数 = 2 I + 1
在没有外磁场时，自旋核的取向是任意的,并且自旋 产生的磁场方向也是任意的.
如:H的I=1/2,则:
1H核 ：自 旋 取 向 数 =2× 1/2+1=2
如即 果： 把H H核 核在 放外 在场 外有 磁两 场个 中自 ,由旋 于方 磁向 场相 间反 的的 取 相向 互。 作用, 氢核的磁场方向会发生变化:
第六章 核磁共振波谱分析法
nuclear magnetic resonance spectroscopy; NMR
第一节 核磁共振基本原理
principles of nuclear magnetic resonance
2022/3/22
核磁共振波谱学的发展 This paper mainly introduces the design of an intelligent temperature control system which realizes the function of temperature measurementand control by using single bus digitaltemperature sensor DS18B20 and single chip microcomputer. The core components of the system are AT89C51 microcontroller and DS18B20 temperature sensor.