Crocodile, butterfly, cat, hen, tortoise, panda, what is oviparous, who is viviparous?

Crocodiles, butterflies, hens, turtles are oviparous. Cats and giant pandas are viviparous.

Crocodiles and tortoises are reptiles and oviparous animals. Hens are birds and oviparous animals (the eggs they lay are called eggs). Butterflies are insectoid animals among invertebrates that are also oviparous.

Cats and giant pandas are mammals, which are viviparous, and what comes out are kittens and giant panda cubs.

Discharge cooling is another type of convection cooling. Unlike regenerative cooling, the coolant used for exhaust cooling absorbs heat to the thrust chamber and is discharged out of the combustion chamber instead of entering the combustion chamber to participate in combustion. Direct drain coolant reduces the thrust chamber specific impulse, so the coolant flow for drain cooling needs to be minimized while only using drain cooling at the outlet section of the nozzle that is relatively less heated.

There is also radiative cooling, in which the heat flow is transferred from the combustion products to the thrust chamber, and then the heat is radiated by the thrust chamber wall to the surrounding space. Radiative cooling is characterized by simplicity and small structural mass. It is mainly used in the extension section of large nozzles and the thrust chamber of small thrust engines using high-temperature resistant materials.

When cooling in the thrust chamber of the tissue, a relatively low temperature liquid or gas protective layer is established on the surface of the thrust chamber wall to reduce the heat flow to the thrust chamber wall, reduce the wall temperature, and achieve cooling. Internal cooling is mainly divided into three methods: internal cooling (shield cooling), membrane cooling and diaphoretic cooling of head tissues. After the internal cooling measures are adopted in the thrust chamber, the mixing ratio near the wall of the combustion chamber is different from the optimal mixing ratio in the central area (in most cases, the near-wall layer rich in fuel is used) due to the need to reduce the temperature of the protective layer, resulting in the uneven distribution of the mixing ratio along the cross-section of the combustion chamber, so that the combustion efficiency is reduced to a certain extent.

Membrane cooling is similar to shield cooling in that it cools the thrust chamber wall by establishing a uniform and stable coolant film or air film protective layer near the inner wall surface, except that the coolant used to establish the protective layer is not injected by the injector, but is supplied through a special cooling belt. The cooling band is generally arranged in a cross-section of the combustion chamber or the convergence section of the nozzle. There can be several cooling bands along the length of the combustion chamber.

In order to improve the stability of the membrane, the coolant often flows through the gaps or small holes in the cooling belts, and when sweating is used, the thrust chamber wall or part of the inner wall is made of porous material with a pore diameter of tens of microns. Porous materials are usually sintered with metal powders or pressed with metal mesh. In this case, the number of pores per unit area is increased by making the micropores in the material as evenly distributed as possible.

The liquid coolant penetrates into the inner wall, creating a protective film that reduces the density of the heat transferred to the wall. When the flow rate of liquid coolant used for sweat cooling is above a certain threshold, a liquid film is formed near the wall of the thrust chamber. When the coolant flow rate is below the critical flow, the inner wall temperature will be higher than the coolant boiling point at the current pressure, and some or all of the coolant will evaporate, forming an air film.

In addition to the above thermal protection, there are other thermal protection methods such as: ablation cooling, thermal insulation cooling, hot melt cooling and composite protection of chamber walls. 3. Thermal protection scheme of high enthalpy gas generator Based on the above methods and the actual situation, the thermal protection method of high enthalpy gas generator is obtained.

The combustion chamber of a high-enthalpy gas generator differs from that of a liquid rocket engine, eliminating the front thrust chamber part, making its structure simpler and more effective. Then, the thermal protection involved is the thermal protection part of the combustion chamber wall. As the fuel enters the combustion chamber, it quickly decomposes and releases large quantities.

Goldfish, earthworms, mice, chickens, elephants, crocodiles, pandas, bats, what is viviparity, what is oviparity, that is, viviparity is the baby born in the mother's belly, Luan Sheng's words are born turtle eggs, and then the eggs hatch out of the baby, these you can try to think about it yourself, are very simple questions, in fact, it is not necessary to find the answer completely on the Internet, if you don't know what type of animal is, you can go to the page again, search for the growth environment of that animal, and their reproductive environment.

The ancestor of the viviparous, giant panda is the first panda, which evolved from the bear-like class and was mainly carnivorous. The main branches of the archaeoptera continued to evolve in central and southern China, with one species appearing in the early Pleistocene about 3 million years ago.

Of course, it is viviparous, but it is very small when it is born, and it will take a long time to raise it.

Swans, dinosaurs, giant pandas, bees, Siberian tigers, swans, dinosaurs, bees and soft-shelled turtles are oviparous; Giant pandas and Siberian tigers are viviparous.

Ovoviviparous is a form of reproduction in which the eggs of animals are fertilized in the body and develop in the body. Although the fertilized egg develops into a new individual in the mother's body, the relationship between the embryo body and the mother's structure and physiological functions is not close. The nutrients required for embryonic development mainly depend on the absorption of the yolk of the egg itself, and the embryonic body can also exchange some substances with the mother's fallopian tubes.

This is a reproductive mode formed by the long-term adaptation of animals to the adverse environment, and the actual mother mainly plays a protective and incubating role in the embryo.

The fertilized egg of an animal develops into a new individual in the mother's body before it produces the mother's body. However, the nutrients required for its development still depend on the yolk stored by the egg itself, and there is no material exchange relationship with the mother, or it only exchanges gas with the mother in the later stage of embryonic development and has little nutritional connection. It is a situation between oviparity and viviparity.

Cone tooth sharks, star sharks, certain venomous snakes (e.g., pit vipers, sea snakes), and viviparous lizards, such as the Aphyllous Drake, are ovoviviparous.

In the process of sexual reproduction of animals, although the new individual produced is not an egg but a juvenile form, there is a yolk for embryonic nutrition in the mother's body, and the development of the embryo does not directly depend on the mother's nutrition, but only the egg develops and hatches in the mother's body, which is different from the real viviparity of mammals that obtains nutrition by contacting the tissues between the mother, so this kind of reproduction is called ovoviviparity. Pit vipers, field snails, and some fish are ovoviviparous. However, in fish, there are also other ways to develop by maternal nutrition, which is also a true form of viviparity.

For example, crucian carp fertilize, develop, and hatch in the ovaries, while larvae take in nutrients from ovarian tissues in the ovarian cavity through the body epithelium and gill foramen before opening. In addition, sharks and rays rely on yolk for their initial development, but when the yolk is exhausted, they are connected to the so-called uterus in the lower part of the fallopian tube through the yolk sac (there are many villi on the inner wall) and receive nutrients from the mother, behaving similarly to the true viviparity of mammals. In addition, in terms of in vivo fertilization, some have undergone a certain degree of development in the mother's body before laying eggs (such as birds), which can also be called ovoviviparity in the generalized sense.

Poisonous egg-laying mammals.

Mammals, from mice to humans, are viviparous and feed their babies with their own milk. Reptiles and birds are oviparous, however, the platypus is completely different and turns out to be an egg-laying mammal.

During the breeding season, adult platypuses dig a special hole in the river bank with the wide nails on their front feet. The cave is about 30 meters long and contains one or more small nests.

The female platypus lays 2 or 3 soft-shell eggs, and the pups hatch after 10 days. Since then, they have behaved more and more like mammals: young platypuses eat their mother's milk until they are old enough to leave their burrows.

Platypus is a carnivore --- preys on insects and some other small animals that live on the bottom of flowing streams and rivers. Underwater, the platypus closes its eyes and uses its soft, sensitive mouth to fumble in the mud in search of food.

The platypus is an expert swimmer, paddling with its webbed feet on its forelimbs and orienting itself on its hind limbs.

The platypus is one of the very few mammals that defends itself with venom. The male platypus has a hollow spiny on the back of its knee that releases venom when it stabs enemies with its hind limbs.

Viviparous! It's an amphibian reptile. It seems that except for snakes, which are oviparous, all other reptiles are viviparous.

Oviparous platypus is a very special milky monomorphus endemic to Australia. Its beak and feet resemble that of a duck and its tail resemble that of a beaver, and it is one of only three mammals in the world that lay eggs.