China's contribution to the world.

Papermaking is one of the four great inventions in China. Paper is the crystallization of the long-term experience and wisdom of the ancient working people in China. This is an outstanding invention in the history of human civilization.

China is the first country in the world to raise silkworms and weave silk. In ancient China, the working people spun silk from superior cocoons, and the remaining evil cocoons and diseased cocoons were made into silk floss by bleaching. After floating, some residual flocs will be left on the mat.

When the flossing frequency is high, the residual flossing on the pad will accumulate into fiber sheets, which can be peeled off after drying and can be used for writing. This kind of floc is called "He Qi" or "square floc" in ancient books because of its small number of by-products. This shows that the origin of ancient papermaking in China is related to silk floss.

2. Compass

Compass, called Sina in ancient times, is mainly composed of magnetic needles installed on the shaft. Under the action of natural geomagnetic field, the magnetic needle can rotate freely and keep in the tangential direction of magnetic meridian. The north pole of the magnetic needle points to the north pole, so this property can be used to identify the direction.

It is often used in navigation, geodesy, tourism and military affairs. The invention of the compass with physical direction indication has three parts, namely Sina, compass and magnetic needle, all of which belong to the invention of China. According to ancient mine records, it first appeared in the Cishan area during the Warring States Period.

Compass is the result of China ancient working people's understanding of magnet magnetism in long-term practice. As one of four great inventions of ancient china, its invention has played an inestimable role in the development of human science, technology and civilization. In ancient China, the compass was first used for rituals, etiquette, military affairs and divination, and to determine the orientation when looking at geomantic omen.

3, gunpowder

Gunpowder, also known as black powder, is a mechanical mixture of potassium nitrate, charcoal and sulfur. It is a substance that can burn quickly and regularly under the action of appropriate external energy, and at the same time produce a large number of high-temperature gases.

Militarily, it is mainly used as the propellant of bullets and shells, the propellant of rockets and missiles and the energy source of other driving devices, which is an important part of ammunition. Gunpowder is one of the four great inventions in China, and it has also changed the history of human wars.

Step 4 print

Printing is one of the four great inventions of working people in ancient China. Engraving printing was invented in the Tang Dynasty and was widely used in the middle and late Tang Dynasty. In Song Renzong, Bi Sheng invented movable type printing. Although movable type printing appeared in Song Dynasty, it was not widely used, while block printing was still widely used.

Printing is the forerunner of modern human civilization, which creates conditions for the wide spread and exchange of knowledge. Printing first spread to Korea, Japan, Central Asia, West Asia and Europe.

5. The contribution of Compendium of Materia Medica to world medicine

Compendium of Materia Medica, 52 volumes. Li Shizhen (Dongbi) in Ming Dynasty was written in the 31st year of Jiajing (1552) to the 6th year of Wanli (1578), and it was revised three times. This book is written in the style of "outline", so it is named "outline". Revise it based on Zheng Ben Cao. The preface is equivalent to the general introduction, which describes the main books of materia medica and the theory of medicinal properties.

Volume 1 Materia Medica of Past Dynasties introduces 4 1 species of main materia medica before the Ming Dynasty. The second time, I collected the discourses about the yin-yang smell of drugs, five taboos, specimen yin-yang, ups and downs, reinforcing and reducing, quoting classics, and various drug taboos before the Ming Dynasty, most of which were in the Jin and Yuan Dynasties.

Volumes 3 ~ 4 are "Indicating Drugs for All Diseases", which follow the old example of "General Drugs for All Diseases" in "Materia Medica of Syndrome Types", and list the names and main functions of indications with evil as the key link, which is equivalent to a manual of clinical medication. Volumes 5-52 are all about the theory, including 1892 kinds of drugs, and the attached figure is 1 109 kinds. Its general example is "there is no difference between the three products, but one after another;" Things follow the class, eyes follow the outline. "

Among them, 16 series (water, fire, soil, stone, grass, valley, vegetable, fruit, wood, utensils, insects, scales, vectors, birds, animals and people) are scored as 60 categories. According to "from micro to giant" and "from humble to expensive", every department is convenient to search, which embodies the idea of biological evolution and development.

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