CN114735392A

CN114735392A - Moisture-proof structure for logistics goods shelf and use method thereof

Info

Publication number: CN114735392A
Application number: CN202210632012.0A
Authority: CN
Inventors: 华长清
Original assignee: Jiangsu Yashang Logistics Technology Co ltd
Current assignee: Jiangsu Yashang Logistics Technology Co ltd
Priority date: 2022-06-07
Filing date: 2022-06-07
Publication date: 2022-07-12

Abstract

The invention provides a moisture-proof structure for a logistics goods shelf and a using method thereof, and relates to the logistics goods shelf. The moistureproof structure for the logistics goods shelf and the using method of the moistureproof structure comprise the goods shelf, wherein a plurality of placing tables are fixedly connected to the inner wall of the goods shelf, moistureproof bases are fixedly connected to the upper surfaces of the placing tables, hydrogel with different contents is placed on the inner walls of the moistureproof bases, and through holes are formed in the upper surfaces of the moistureproof bases. Through the automatic analysis equipment and the automatic operation equipment that set up, make equipment can carry out corresponding placing to the object of difference according to the dampproofing demand of commodity circulation article for every article can both be accurate reasonable deposit and accomodate, especially when accomodating the article of food type, the grasp that can be accurate its water activity ratio, make food can be long-time when placing preserve the processing, improved the dampproofing of commodity circulation goods shelves, protection, save the effect, should carry out the wide application.

Description

Moisture-proof structure for logistics goods shelf and use method of moisture-proof structure

Technical Field

The invention relates to the technical field of logistics goods shelves, in particular to a moistureproof structure for a logistics goods shelf and a using method thereof.

Background

The goods shelves are important tools for improving the efficiency of the modern warehouse, along with the rapid development of economy, foreign enterprises are greatly rushed into Yangtze river delta and Zhujiang delta in China, so that the development of local economy is driven, new management ideas and management technologies are brought, and the kinds of the goods shelves used by the warehouse of the enterprise tend to be more and more automatic and intelligent.

The applicant finds, through search among the inventions, that a chinese patent discloses "an antirust moisture-proof shelf for mechanical structure formation column", which has a publication (publication) number of "CN 212280528U", and the patent mainly blows hot air inside a hollow cavity through a vent hole by wind power transmitted by a fan, and then blows the hot air to the surface of a mechanical structure on the surface of a placing plate through the vent hole, so as to increase the temperature of the air around the mechanical structure, thereby avoiding the moisture of the air around the mechanical structure from being large, preventing the mechanical structure from rusting, thereby improving the aesthetic property of the mechanical structure, and also finds, through search, that the chinese patent discloses "a moisture-proof shelf for electronic commerce storage", which has a publication (publication) number of "CN 114044291A", and the patent mainly discloses a series of structures, two sets of partition mechanisms are arranged through the partition mechanisms, and the use space area of a connecting frame can be enlarged by removing the number of the partition mechanisms, conveniently place the commodity of the electronic commerce of broad, the clearance subassembly sets up in the bottom of link, handheld pulling frame, the clearance brush through the clearance frame removes at the outer wall end of link, can effectually clear up the outer wall end of link and goods shelves fast, the underframe frame is installed to the bottom of link, the person of facilitating the use installs the clearance subassembly, but two patents above all do not carry out analysis processes to the article of placing, only simple article place the processing, make different article can not obtain fine storage when depositing, especially food type's article, because the absorbing water and the water content of itself are different when placing, so the environment that needs when dampproofing the processing also is different.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a moisture-proof structure for a logistics goods shelf and a using method thereof, and solves the problems that the traditional goods shelf does not analyze and process placed articles, but simply places and processes the articles, so that different articles cannot be well stored when being stored, particularly food type articles, and the environment required by moisture-proof processing is different due to different water absorption and water content of the articles when being placed.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a dampproof structure for a logistics goods shelf and a using method thereof comprise the goods shelf, wherein the inner wall of the goods shelf is fixedly connected with a plurality of placing tables, the upper surfaces of the placing tables are fixedly connected with dampproof bases, hydrogel with different contents is placed on the inner wall of the dampproof bases, the upper surfaces of the dampproof bases are provided with through holes, the upper surfaces of the dampproof bases are fixedly connected with placing boxes, the two sides of the goods shelf are fixedly connected with electric slide rails, the surfaces of the two electric slide rails are connected with mechanical arms through the electric slide blocks in a sliding manner, detection tables are arranged below the two sides of the goods shelf, the inner wall of each detection table is provided with a nuclear magnetic resonance device, the opposite sides of the upper surfaces of the two detection tables are fixedly connected with an infrared moisture tester, and the devices can reasonably place different objects, the inner walls of the placing boxes with different damp-proof effects can be accurately placed on the articles with different requirements.

Preferably, it is a plurality of place the equal fixedly connected with installation shell of upper surface of box, it is a plurality of the equal fixedly connected with motor in one side of installation shell inner wall, it is a plurality of the equal fixedly connected with dwang of output of motor, it is a plurality of the equal fixedly connected with connecting piece in lever arm one side of dwang, it is a plurality of place the surface of box all seted up with connecting piece assorted opening, it is a plurality of the front side of connecting piece all extends to corresponding box front side of placing, a plurality of the equal fixedly connected with sealing door board of one end of connecting piece, it is a plurality of the equal fixedly connected with of rear side surface of sealing door board fills up, and is a plurality of the sealed rear side of filling up is equallyd divide do not with corresponding box surface contact of placing, can place corresponding box inside back of placing at article and carry out the self-sealing to it and handle.

A use method of a moisture-proof structure for a logistics goods shelf comprises the following specific use methods:

s1, sampling, placing and detecting, namely placing the logistics objects to be stored on one of the detection tables, and then detecting the water activity of the objects by an infrared water content meter and a nuclear magnetic resonance device;

s2, selecting by the terminal through detection, detecting the water activity of the article through the infrared moisture meter and the nuclear magnetic resonance device, enabling the terminal to select the position where the article is suitable to be placed through an internal algorithm, and sending an instruction to the driving device;

s3, driving to operate and place, starting an instrument arm through an issued instruction by a terminal, driving an article to be placed to move to clamp by the mechanical arm, then sending an instruction to an electric sliding rail by the terminal again to start the electric sliding rail, driving the mechanical arm to move to the same height of a corresponding placing table by the electric sliding rail, driving the article to be placed to move to a corresponding placing box by the mechanical arm, then starting a corresponding motor by the terminal again, driving a fixedly connected rotating rod by the corresponding motor to rotate, driving a fixedly connected connecting piece to rotate by the rotating rod, driving a fixedly connected sealing door plate to open by the connecting piece, and then placing the article to be placed into the corresponding placing box by the mechanical arm;

s4, the drive is closed, after placing article corresponding placing box inside, the terminal gives an instruction to robotic arm and electric slide rail, make two arms resume initial running state and position department, and give an instruction to the motor that starts, the motor just drives fixed connection 'S dwang antiport, the dwang drives fixed connection' S connecting piece and carries out the antiport, the connecting piece drives sealed door plant and closes, make sealed the pad of sealed door plant cooperation rear side close the placing box of opening, later the aquogel of corresponding content can carry out fine dampproofing processing through the through-hole to the article of putting into.

Preferably, the GDW model is derived by principle during the terminal detection, and can be evolved into a GAB model and a BET model under specific conditions of parameters thereof, where an expression of the GAB model is as follows:

in the formula, Me is the equilibrium water content under each relative humidity, g/100g d.b;

aw-water activity of the food;

m 0-adsorption on monomolecular layer, g/100g d.b

c-kinetic constants associated with adsorption of the first layer;

k-kinetic constants associated with adsorption of the polymolecular layer;

the expression of the GDW model is as follows:

in the formula, Me represents the equilibrium water content under each relative humidity, g/100g d.b;

m is the maximum adsorption capacity of the first layer of water adsorption, g/100g d.b;

k and K-kinetic constants associated with moisture adsorption of the first and second layers;

w-the ratio of the water molecules adsorbed by the first layer to the second adsorbed layer.

Preferably, the terminal can perform activity chart generation on the placed object when analyzing the water activity, and when the water activity is greater than 0.7, the slope of the water adsorption isotherm is obviously increased, and the water adsorption speed is accelerated.

Preferably, from the parameters obtained by GAB model fitting, the water content of the monomolecular layer obtained by the saturated salt solution method of 4.297g/100g is slightly higher than that of the monomolecular layer obtained by the dynamic water adsorption method of 3.864g/100g, which indicates that the longer equilibration time of the saturated salt solution method is favorable for the formation of the monomolecular adsorption layer, and from the GAB model fitting evaluation index, the determination coefficients R-square are respectively 0.9993 and 0.9991.

Preferably, the values of the first layer water adsorption kinetic constant K are all larger than 1 according to the GAB model, which indicates that the food is relatively sensitive to humidity, the water adsorption isotherm belongs to the class II, the values of the second layer water adsorption kinetic constant K are basically close to 1, and the value of w is between 1 and 2, which indicates that more than 1 second layer water molecule may be adsorbed on each first layer adsorbed water molecule, and the K value and the K value are determined according to the GDW model.

Preferably, the GAB model is fitted with parameters and evaluation indexes obtained by fitting the data of the adsorption of the 3 biscuits, and the determination coefficients R-square are 0.9919, 0.9943 and 0.9927 respectively, which shows that the GAB model has a very good fitting effect, the K value in the GAB model is close to 1 but less than 1, which is also a typical result of the water adsorption of the food, the K value represents the difference between the standard chemical potential of water molecules in the second adsorption layer and the chemical potential of pure water, and the single-layer water adsorption content m0 in the GAB model describes the water content of the first layer when the water adsorption is saturated, and represents the number of positions of water molecules capable of being adsorbed in the food.

Preferably, there is a large correlation between the water content of the food product and its stability, however some food products, although having the same water content, have significantly different stabilities, partly because of the differences in the binding strength of water to the non-water components of the food product, which cannot be measured by conventional methods, NMR techniques, which are highly interpreted by the polymers, including the water activity of the food product, allow a comprehensive analysis of the water presence in the food product, and the terminal analyses the water content differences of the analysed product, and introduces a rectangular coordinate system, where the direction of B0 is Z, where Mz = M0, is the same as the direction of the magnetic field B0, and where the magnetization vector deviates from the Z-axis direction if the radio frequency field B1 is applied perpendicular to the direction of the magnetic field B0 (90 °), once the action of the radio frequency pulse field B1 ceases, the spin nuclear system automatically restores from an unbalanced state to a balanced state and releases energy absorbed from the radio frequency magnetic field, and the time required for the restoration process is the relaxation time.

The working principle is as follows: the logistics objects to be stored are placed on one of the detection tables 9, then the infrared moisture meter 10 and the nuclear magnetic resonance device detect the water activity of the objects, the terminal selects the water activity of the objects through detection, the infrared moisture meter 10 and the nuclear magnetic resonance device detect the water activity of the objects, the terminal selects a position where the objects are suitable to be placed through an internal algorithm, sends an instruction to the driving device to drive the driving device to be placed, the terminal starts the instrument arm through the sent instruction, the mechanical arm 8 drives the objects to be placed to move to clamp up, then the terminal sends an instruction to the electric sliding rail 7 again to enable the electric sliding rail 7 to start, the electric sliding rail 7 drives the mechanical arm 8 to move to the same height of the corresponding placing table 2, and then the mechanical arm 8 drives the objects to be placed to move to the corresponding placing box 6, then the terminal starts the corresponding motor 12 again, the corresponding motor 12 drives the fixedly connected rotating rod 13 to rotate, the rotating rod 13 drives the fixedly connected connecting piece 14 to rotate, the connecting piece 14 drives the fixedly connected sealing door panel 16 to open, then the mechanical arm 8 places the article to be placed into the corresponding placing box 6, after the article is placed into the corresponding placing box 6, the terminal sends an instruction to the mechanical arm 8 and the electric sliding rail 7 to enable the two arms to recover to the initial running state and position, and sends an instruction to the started motor 12, the motor 12 drives the fixedly connected rotating rod 13 to rotate reversely, the rotating rod 13 drives the fixedly connected connecting piece 14 to rotate reversely, the connecting piece 14 drives the sealing door panel 16 to close, so that the sealing gasket 17 on the rear side of the sealing door panel 16 is matched with the opened placing box 6 to close, then, hydrogel 4 with corresponding content can well perform moisture-proof treatment on the placed articles through the through holes 5.

(III) advantageous effects

The invention provides a moisture-proof structure for a logistics goods shelf and a using method thereof. Possess following beneficial effect, can carry out corresponding placing to different objects according to the dampproofing demand of commodity circulation article for every article can both be accurate reasonable deposit and accomodate, especially when accomodating the article of food type, the grasp that can be accurate its water activity ratio, make food can be long-time when placing preserve the processing, improved the dampproofing of commodity circulation goods shelves, protection, save the effect, should carry out extensive application.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic perspective view of the placing table 2;

FIG. 3 is a schematic front sectional view of the storage box 6;

FIG. 4 is a comparative water activity analysis diagram;

FIG. 5 is a comparative schematic of water activity analysis;

FIG. 6 is a comparative water activity analysis diagram;

FIG. 7 is a comparative water activity analysis diagram;

fig. 8 is a diagram illustrating a state of deviation of magnetization vectors after application of a radio frequency field B.

Wherein, 1, a shelf; 2. a placing table; 3. a moisture-proof base; 4. a hydrogel; 5. a through hole; 6. placing the box; 7. an electric slide rail; 8. a robot arm; 9. a detection table; 10. an infrared moisture meter; 11. mounting a shell; 12. a motor; 13. rotating the rod; 14. a connecting member; 15. an opening; 16. a sealing door panel; 17. and a gasket.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

as shown in fig. 1-8, the embodiment of the present invention provides a moisture-proof structure for logistics goods shelves and a method for using the same, which is performed by placing a logistics object to be stored on one of the detection platforms 9, and then detecting the water activity of the object by using an infrared moisture meter 10 and a nuclear magnetic resonance device;

the terminal selects through detection, the water activity of the article is detected through the infrared moisture tester 10 and the nuclear magnetic resonance device, so that the terminal selects a position where the article is suitable to be placed through an internal algorithm, and sends an instruction to the driving device;

during analysis, a GDW model is deduced through a terminal, the GDW model can be evolved into a GAB model and a BET model under the specific condition of parameters of the GAB model and the GDW model, the slope of a water adsorption isotherm is obviously increased and the water adsorption speed is accelerated after the water activity is more than 0.7, from the view of the parameters obtained by the GAB model fitting, the water content of a monomolecular layer obtained by a saturated salt solution method is 4.297g/100g which is slightly higher than that of a dynamic water adsorption method by 3.864g/100g, which indicates that the longer equilibrium time of the saturated salt solution method is favorable for the formation of a monomolecular adsorption layer, from the view of GAB model fitting evaluation indexes, the determining coefficients R-square are respectively 0.9993 and 0.9991, and from the view of the GAB model fitting, the value of a first layer water adsorption kinetic constant K is more than 1, which indicates that the corresponding product is relatively sensitive to humidity, the water adsorption isotherm belongs to class II, and the dynamic constant K of the water adsorption of the second layer is basically close to 1, and the value of w is between 1 and 2, which shows that more than 1 water molecule of the second layer can be adsorbed on each water molecule adsorbed by the first layer according to the K value and the K value of the GDW model;

the parameters and evaluation indexes obtained by the GAB model fitting the data of the 3 biscuits have the determining coefficients R-square of 0.9919, 0.9943 and 0.9927 respectively, which shows that the GAB model has very good fitting effect, the K value in the GAB model is close to 1 but less than 1, the value is also a typical result of food moisture adsorption, the K value represents the difference between the standard chemical potential of water molecules in the second adsorption layer and the chemical potential of pure water, the single-layer moisture adsorption content m0 in the GAB model describes the moisture content of the first layer when the moisture adsorption is saturated, the position of water molecules in the food can be adsorbed, and the relationship between the moisture content of the food and the stability of the food is large, however, some foods have the same moisture content but the stability is remarkably different, and the reason of this is partly the difference of the bonding strength of water and the non-water components in the food, the difference cannot be tested by adopting a traditional method, the NMR technology is used for explaining the water activity of polymers including food, the NMR technology can be used for comprehensively analyzing the form of water in the food, the terminal can be used for analyzing the water-containing difference of the analyzed object, a rectangular coordinate system is introduced into the terminal, the direction of B0 is Z, the Mz = M0 is the same as the direction of a magnetic field B0, if a radio frequency field B1 is applied in the direction perpendicular to the direction of B090 DEG of the magnetic field, the magnetization intensity vector deviates from the direction of the Z axis, once the action of a radio frequency pulse field B1 is stopped, a spin-nucleus system automatically restores to a balanced state from an unbalanced state and releases energy absorbed from the radio frequency magnetic field, and the time required by the restoring process is relaxation;

then the terminal starts the instrument arm through the sent instruction, the mechanical arm 8 drives the object to be placed to move and clamp, then the terminal sends the instruction to the electric sliding rail 7 again, so that the electric sliding rail 7 starts, the electric sliding rail 7 drives the mechanical arm 8 to move to the same height of the corresponding placing table 2, then the mechanical arm 8 drives the object to be placed to move to the corresponding placing box 6, then the terminal starts the corresponding motor 12, the corresponding motor 12 drives the fixedly connected rotating rod 13 to rotate, the rotating rod 13 drives the fixedly connected connecting piece 14 to rotate, the connecting piece 14 drives the fixedly connected sealing door panel 16 to open, and then the mechanical arm 8 places the object to be placed into the corresponding placing box 6;

at last place corresponding placing box 6 inside with article after, the terminal gives an instruction to robotic arm 8 and electronic slide rail 7, make two arms resume initial running state and position department, and give an instruction to the motor 12 that starts, motor 12 just drives fixed connection's dwang 13 antiport, dwang 13 drives fixed connection's connecting piece 14 and carries out the antiport, connecting piece 14 drives sealed door plant 16 and closes, make sealed pad 17 of sealed door plant 16 cooperation rear side close the placing box 6 of opening, later the aquogel 4 of corresponding content can carry out fine dampproofing to the article of putting into through-hole 5 and handle.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a commodity circulation goods shelves (1) are with dampproofing structure, includes goods shelves (1), its characterized in that: the inner wall of the goods shelf (1) is fixedly connected with a plurality of placing tables (2), the upper surfaces of the placing tables (2) are fixedly connected with damp-proof bases (3), the inner walls of the damp-proof bases (3) are respectively provided with hydrogel (4) with different contents, the upper surfaces of the damp-proof bases (3) are respectively provided with through holes (5), the upper surfaces of the damp-proof bases (3) are respectively fixedly connected with a placing box (6), both sides of the goods shelf (1) are fixedly connected with electric sliding rails (7), the surfaces of the two electric sliding rails (7) are connected with mechanical arms (8) through electric sliding blocks in a sliding manner, the lower part of goods shelves (1) both sides all is provided with detects platform (9), the inner wall that detects platform (9) is provided with nuclear magnetic resonance device, two detect equal fixedly connected with infrared moisture meter (10) in one side that platform (9) upper surface is opposite.

2. The moisture-proof structure for the logistics pallet (1) of claim 1, wherein: it is a plurality of place the equal fixedly connected with installation shell (11) of upper surface of box (6), it is a plurality of the equal fixedly connected with motor (12) in one side of installation shell (11) inner wall, a plurality of the equal fixedly connected with dwang (13) of output of motor (12), it is a plurality of the equal fixedly connected with connecting piece (14) in lever arm one side of dwang (13), it is a plurality of place the surface of box (6) all seted up with connecting piece (14) assorted opening (15), it is a plurality of the front side of connecting piece (14) all extends to corresponding box (6) front side of placing through corresponding opening (15), it is a plurality of the equal fixedly connected with sealing door board (16) of one end of connecting piece (14), it is a plurality of the equal fixedly connected with of rear side surface of sealing door board (16) seals up the pad (17), it is a plurality of the rear side of sealed pad (17) is equallyd divide do not with corresponding box (6) surface contact of placing.

3. The use method of the damp-proof structure for the logistics goods shelf is characterized by comprising the following steps: the logistics goods shelf (1) is provided with a damp-proof structure under the specific method:

s1, sampling, placing and detecting, namely placing the logistics objects to be stored on one of the detection tables (9), and then detecting the water activity of the objects by the infrared moisture meter (10) and the nuclear magnetic resonance device;

s2, selecting by the terminal through detection, detecting the water activity of the article through an infrared moisture meter (10) and a nuclear magnetic resonance device, selecting a position where the article is suitable to be placed by the terminal through an internal algorithm, sending an instruction to a driving device, deducing a GDW model through a principle when detecting the terminal, and evolving into a GAB model and a BET model under specific conditions of parameters of the GDW model, wherein the expression of the GAB model is as follows:

；

the expression of the GDW model is as follows:

；

s3, driving to operate and place, starting the arms of the instrument by the terminal through the sent command, driving the articles to be placed to move and clamp by the mechanical arm (8), then the terminal sends an instruction to the electric sliding rail (7) again to start the electric sliding rail (7), the electric sliding rail (7) drives the mechanical arm (8) to move to the same height of the corresponding placing platform (2), then the mechanical arm (8) drives the object to be placed to move to the corresponding placing box (6), then the terminal starts the corresponding motor (12), the corresponding motor (12) drives the fixedly connected rotating rod (13) to rotate, the rotating rod (13) drives the fixedly connected connecting piece (14) to rotate, the connecting piece (14) drives the fixedly connected sealing door panel (16) to open, then the mechanical arm (8) places the articles to be placed into the corresponding placing box (6);

s4, the drive is closed, after placing corresponding box (6) inside with article, the terminal sends out the instruction to robotic arm (8) and electronic slide rail (7), make two arms resume initial running state and position department, and send out the instruction to the motor (12) that starts, motor (12) just drive fixed connection 'S dwang (13) antiport, dwang (13) drive fixed connection' S connecting piece (14) and carry out the antiport, connecting piece (14) drive sealed door board (16) are closed, make sealed door board (16) cooperation rear side sealed pad (17) close the box (6) of placing of opening, later the hydrogel (4) of corresponding content can carry out fine dampproofing to the article of placing through-hole (5).

4. The use method of the moisture-proof structure for the logistics goods shelves according to claim 3, characterized in that: and the terminal can perform activity chart generation on the placed object when analyzing the water activity.

5. The use method of the moisture-proof structure for the logistics shelf as claimed in claim 5, wherein the moisture-proof structure comprises the following steps: from the parameters obtained by GAB model fitting, the water content of the monomolecular layer obtained by the saturated salt solution method of 4.297g/100g is slightly higher than that of 3.864g/100g obtained by the dynamic water adsorption method.

6. The use method of the moisture-proof structure for the logistics goods shelves according to claim 5, characterized in that: and fitting the GAB model to ensure that the values of the first layer water adsorption kinetic constant K are all larger than 1, which indicates that the food is relatively sensitive to humidity, the water adsorption temperature line belongs to the class II, the second layer water adsorption kinetic constant K is basically close to 1, and the value w is between 1 and 2.

7. The use method of the moisture-proof structure for the logistics shelf as claimed in claim 5, wherein the moisture-proof structure comprises the following steps: parameters obtained by fitting the GAB model to the adsorption data of 3 biscuits and evaluation indexes, and determining coefficients of the parameters

R-square is 0.9919, 0.9943 and 0.9927 respectively, and the k value in the GAB model is close to 1.

8. The use method of the moisture-proof structure for the logistics shelf as claimed in claim 3, wherein the moisture-proof structure comprises the following steps: the NMR relaxation technique is intended to provide a strong explanation of the water activity of polymers, including food products, and the NMR technique is used to analyze the presence of water in food products comprehensively, and the terminal analyzes the water-containing variability of the analyzed products, and introduces a rectangular coordinate system, wherein the direction of B0 is Z, the direction of Mz = M0 is the same as that of the B0 magnetic field, if the B1 rf field is applied in the direction perpendicular to the B0 (90 °), the magnetization vector deviates from the Z-axis direction, once the B1 rf pulse field ceases, the spin-nuclear system automatically returns from the unbalanced state to the balanced state and releases the energy absorbed from the rf magnetic field, and the time required for this recovery process is the relaxation time.