Cultural connotation of lock
Locks are not only the daily necessities of human beings, but also cultural (folk) objects, which represent the culture of a country and a nation in different historical periods. China's locks have been stretched for thousands of years, and it was born almost simultaneously with human ownership. At first, humans simply wrapped their valuables with animal skins, tied them tightly with ropes, and finally put a special knot on the opening. This tightly tied knot can only be picked up with a tool called "wrong". Wrong, also called "Shaw", "", "starter". It is made of animal teeth or animal bones, shaped like a sickle-shaped hook. In fact, the knot is the earliest lock. "" is the earliest key. This is the prototype of our country's locks. This kind of used from the Shang Dynasty to the Han Dynasty, and later changed to jade system, evolved into a decorative ornament on the aristocratic costume. In the Yangshao culture period of 5,000 years ago, the Chinese ancestors created wooden locks mounted on wooden framed buildings (see "China Encyclopedia·Light Work Volume"). This is the oldest lock in the world and can be called the "world's first lock." This kind of wooden lock has been passed down in the folk, such as the white wood lock of the Ming Dynasty, which was used in the construction of the Zhejiang area. There are similar wooden locks in the Kunming Yi village. Although Yin Shang has entered the Bronze Age, it mainly uses copper to make large-scale drinking utensils, food utensils and rituals, which have not been used to make locks. Its development period was from the Qin, Han, Wei, Jin, Southern and Northern Dynasties to the Sui, Tang and Song Dynasties. After the Qing Dynasty in the Qing Dynasty, the Spring and Autumn Period entered the Iron Age. Archaeology proved that during this period, people used iron locks, copper locks, silver locks, gold locks, etc., such as the bronze of the Western Zhou Dynasty. The locks, the metal locks of the Eastern Han Dynasty, the silver tail locks of the Tang Dynasty, and the locks of the Song Dynasty have a fairly high level of technology. In particular, the iron three-spring lock of the Han Dynasty has been used for more than 1,000 years in China. Its prosperity period was during the Ming and Qing Dynasties. The locks of various materials developed synchronously. The copper locks and iron locks were mostly used, and the craftsmanship was more elaborate. There was great innovation in the difficulty of unlocking and the shape manufacturing. For example, the three-color copper lock of the Ming Dynasty, the white crane lock of the Qing Dynasty, the code lock, the secret door lock, the four-lock lock, the inverted zipper, and the locks of various characters, animals and characters are dazzling and beautiful. Some locks have a complicated structure, a clever design, and a strange mechanism, which is difficult for ordinary people to open. Ancient locks in China have not only a long history, but also a wide variety of them, which are exquisitely manufactured and have rich cultural connotations. Compared with modern locks, there are at least three characteristics: - Chinese traditional locks have a long history. At least 5,000 years of history, and there are many types, rich in reserves and profound cultural heritage; the time of modern locks developed in China, from 1887 For the first time, China Merchants Bank used the US "Yale" brand pin locks, and it has only been more than 100 years. ——The traditional Chinese locks are made by hand crafts, which makes the creativity of the process fully exerted. The artists of the past generations have been constantly innovating in craftsmanship, with exquisite skills and rich styles. From the collection of hundreds of locks and pictures used by various ethnic groups in my collection, the materials are divided into wooden locks, gold locks, silver locks, brass locks, iron locks, cloisonne locks, etc. Citi lock, criminal lock, jewelry lock, etc.; according to the form, there are round lock, square lock, pillow lock, text lock, character lock, animal lock, password lock, dark door lock, reverse lock, barrel lock, straight lock , horizontally open locks, etc.; according to the use, there are padlocks, door locks, box locks, cabinet locks, box locks, drawer locks, warehouse locks, etc.; from the technical point of view, there are flat carving, openwork, hollow carving, silk flowers, sheet metal , wrong gold, gold, gold, inlay and mold casting. These locks are not only for living things for people, but also for their high artistic value, which can be appreciated and collected. Chinese traditional locks also contain profound cultural connotations, which are incomparable with modern locks. For example, when the bride is married, she uses the "12 Zodiac" lock on the dowry box; the folk uses the "Fu Lu Shou Xi" lock when she is doing life; the child's birthday is long life lock, Bao Jiabai lock, money lock and so on. These locks not only have words, but also engrave pictures, stories, and meanings are very profound.The commonly used Pipette kits are mainly composed of a pipette and a pipette tip. The pipette tip is a single empty
Cavity reservoir; the pipette uses the principle of air displacement and controls the maximum displacement of the piston by rotating a screw with an ultra-fine thread
displacement, and then control the amount of liquid suction. There are the following problems when using the above kit for suction: 1. The suction volume is controlled by the pipette
After the pipette is sterilized or used for a period of time, it is easy to cause "hidden" failures, which cause the operator to be difficult to detect.
The actual suction volume is inaccurate, and it needs to be adjusted frequently, and the operation is cumbersome and time-consuming; 2. To improve the pipetting accuracy, the operator's
The operation requirements are high, and it is easily affected by factors such as the suction speed, the depth of the tip below the liquid level, and the inclination angle of the pipette.
The actual suction volume will be heard; 3. The actual suction volume will be affected because the suction head cover is not tight and leaking, and it will not be easily detected; 4.
When performing experiments that require high accuracy, such as analysis, in the operation of equal volume aspiration of liquids with different densities, the actual
The actual suction volume will be affected by the density itself; 5. In order to improve the accuracy, this type of pipette needs to carry out high
Cost-optimized design results in extremely high pipette costs.
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