Today, let’s take a look AT the AT gearbox and the dual clutch gearbox, which one should we choose? Please see next.

AT gearbox:Variable speed is realized by hydraulic torque converter and planetary gear set. Hydraulic torque converter uses liquid to transmit power, which can cushion the power impact of the engine; Planetary gear sets realize different transmission ratios according to different combinations.

dualclutchtransmissionThe odd and even gears are controlled by two clutches, which is equivalent to integrating two sets of manual gearboxes. When shifting gears, prepare the next gear in advance to realize fast shifting.

Shift speed: the shift speed of dual clutch gearbox is extremely fast, usually only about 0.2 seconds, while AT gearbox is relatively slow.

Transmission efficiency: the transmission efficiency of dual-clutch gearbox is high, and the power loss is small, which can generally reach about 85%-90%; The transmission efficiency of AT gearbox is relatively low, about 70%-85%.

Driving experience: the dual-clutch gearbox is more direct and neat when shifting gears, which can bring better driving pleasure, but it may have a sense of frustration when driving at low speed; The shift of AT gearbox is relatively smooth and comfortable, but the dynamic response may not be as direct as that of dual clutch gearbox.

Structural complexity: AT gearbox has a complex structure, including hydraulic torque converter, planetary gear set and other components; The structure of dual clutch gearbox is relatively simple, similar to manual gearbox.

Cost: Generally speaking, the manufacturing cost of AT gearbox is high, especially the high-end AT gearbox; The cost of dual clutch gearbox is relatively low, especially dry dual clutch.

Good ride comfort: the existence of hydraulic torque converter makes the shift process softer, the shift feeling is obvious and the driving comfort is high.

Large torque bearing: able to bear large engine torque output, suitable for all types of vehicles, including high performance and large vehicles.

Mature technology: it has a long history of development, relatively mature and stable technology, high reliability and low failure rate.

Simple operation: the driver only needs to control the throttle and brake, and there is no need to manually shift gears, so the operation is simple and easy.

Disadvantages:

Low transmission efficiency: power will be lost in the transmission process, resulting in relatively poor fuel economy.

Complicated structure: The complicated structure makes AT gearbox bulky, heavy and costly to manufacture.

Slow shift speed: compared with the dual clutch gearbox, the shift speed is not fast enough, which affects the dynamic response and acceleration performance of the vehicle to some extent.

High fuel consumption: Due to the low transmission efficiency and its own structural characteristics, the fuel consumption of AT gearbox vehicles is relatively high.

Fast shift speed: it can complete the shift operation in a very short time, and the power interruption time is short, which can provide better acceleration performance and driving experience.

High transmission efficiency: direct power transmission reduces energy loss and improves fuel economy, especially at high speed.

Simple structure: Compared with AT gearbox, it is relatively simple in structure, small in size and light in weight, and easy to install and arrange on vehicles.

Low cost: the manufacturing cost is relatively low, which helps to reduce the price of the whole vehicle.

Disadvantages:

Low-speed setback: Under low-speed driving, frequent start-stop or congested road conditions, there may be setbacks, which will affect driving comfort.

Reliability problem: There were some reliability problems in the early dual-clutch gearbox, such as clutch overheating and wear, but with the continuous improvement of technology, the reliability has been greatly improved.

High heat dissipation requirements: especially for dry dual-clutch gearbox, because there is no oil immersion to dissipate heat, long-term intense driving or frequent gear shifting will easily lead to overheating, which will affect performance and life. The wet dual-clutch gearbox dissipates heat through oil, which is relatively good, but the cost is high.

High maintenance cost: The clutch plates and other parts of the dual-clutch gearbox are vulnerable parts, which may need to be replaced after a certain mileage, which increases the maintenance cost.

So, friends, which gearbox do you prefer?

According to chengdu research base of giant panda official micro-news, recently, under the constant popularization of science and guidance of the panda base, media, caring people and fans, the tour order of the park has gradually become orderly. We are deeply grateful for the pertinent suggestions and help from people from all walks of life! However, during the tour of the panda base,It is still found that some tourists have uncivilized behavior, which is now reported as follows.

Yao Moumou (female, 47 years old), born on April 11, 2023.Throw things into animal houses and other places in the park., destroying the environment, violating the relevant regulations of the panda base for the first time, and has signed a written commitment letter for civilized visit.

Li Moumou (male, 41 years old) was in the park on March 27, 2023.Conduct live webcasts,For the first time, I violated the relevant regulations of the Panda Base and signed a written commitment letter for civilized visit.

Yi Moumou (female, 47 years old), since April 11, 2023.Distribute leaflets in violation of regulations in the park,For the first time, I violated the relevant regulations of the Panda Base and signed a written commitment letter for civilized visit.

Here, Pangda advocates that all tourists and friends practice civilized conventions during the visit, obey the arrangement of the on-site staff and work together to protect the cute giant panda.

For these uncivilized tourists,

Netizens are angry:

Heavy penalty, blacklisted

　　Xinhua News Agency, Chengdu, April 6 (Reporter Yu Li, Feng Changyong) The reporter learned from the China Giant Panda Conservation and Research Center, which has the largest captive giant panda population in the world, that the center has completed nearly half of the breeding and breeding tasks of captive giant pandas this year, and the giant panda breeding has entered a peak period.

　　By the end of 2015, the number of captive giant pandas in the center had reached 218. Zhang Guiquan, director of Ya ‘an Base of China Giant Panda Conservation and Research Center, said that this year, 26 female pandas and 19 male pandas participated in the national captive giant panda breeding program. Since the first female panda was bred in late February, as of April 6, 10 female pandas have been bred. Among them, 6 were bred by natural mating, the other 2 were bred by natural mating with artificial insemination, and the remaining 2 were completely artificially inseminated.

　　"So far, this year’s breeding work has been completed well. The biggest feature is that the natural mating rate is relatively high, and the pregnancy rate of female pandas that have successfully mated naturally is over 90%, which is a good momentum for this year’s breeding work." Zhang Guiquan said.

　　"Under the current captive conditions, the number of male giant pandas with natural mating ability is very rare, accounting for less than 5% of the population. This year, the center belongs to the 7-year-old male giant panda ‘ An An ’ The first successful natural mating at Ya ‘an base on February 29th marks the addition of a male animal with natural mating ability to the captive giant panda population, which also shows that the quality of our captive giant panda population is constantly improving. " Zhang Guiquan said.

　　According to reports, at present, the artificial breeding of captive giant pandas in China is included in the unified planning, and the optimal pairing is carried out according to the principle of eugenics, so as to ensure the genetic diversity of the population to the greatest extent. There are 56 female pandas participating in the breeding program this year, and more than one third of them are from the China Research Center for the Protection of Giant Pandas.

　　There are three major problems in the development of captive giant panda population: difficulty in estrus, difficulty in mating and conception, and difficulty in survival of cubs. According to zhangxin, the breeder of the center, giant pandas are in estrus every spring. With the increase of temperature, their hormone level, estrus behavior and mating desire will decrease from May, which will affect the mating quality. Therefore, March and April are the prime time for giant pandas to breed. In order to ensure that female pandas are pregnant, some will also receive artificial insemination as appropriate after natural mating.

　　In recent years, the artificial breeding of giant pandas in the center has been carried out at Bifengxia base in Ya ‘an. The reporter saw at the base on the 6th that the staff was preparing to breed the 7-year-old female panda "Jojo". Because Jojo’s estrus behavior was not typical enough, she was not allowed to mate naturally. In this regard, Zhang Guiquan said that this is a normal situation.

　　It is reported that female giant pandas not only have a short estrus time, but also need to mate with each other to be successful. If there is no electricity between pandas, mating may fail even during estrus. In addition, even if natural mating is successful, it is very difficult for female giant pandas to finally give birth to panda babies — — Their eggs can only survive for 36 to 40 hours. Even with breeding, only 30% to 40% of female giant pandas can get pregnant successfully, while the survival rate of their cubs is less than 40%.

　　[car home new car on the market] Recently, BMW officially announced (|) that it was officially launched for sale. The new car includes two versions, i4 eDrive40 and i4 M50.The price is 449,900 yuan and 539,900 yuan respectively..

『i4 eDrive40』

　　The design of the new car is similar to that of the BMW 4 Series, and the front face is a huge kidney grille with high recognition. The smooth coupe body design and the hatchback tailgate with strong practicability are expected to be attractive to young consumers. It is worth mentioning that the car will also come standard with M sports kit and star screen air intake grille.

『i4 M50』

　　For the i4 M50 version, the new car will adopt M aerodynamic components, blue M high-performance brake calipers, M family exclusive exterior rearview mirror design, M rear spoiler, M Performance exclusive cerium-gray exterior decoration, M Performance exclusive 19-inch wheels and M tricolor steering wheel stitching, etc., and can choose frosted Portiman blue exclusive car paint.

　　The interior level is also BMW’s latest design style. In front of the driver is a dual-screen composed of a 12.3-inch full LCD instrument and a 14.9-inch central control panel, with the latest iDrive 8.0 information system built in. The system can integrate more third-party applications, such as WeChat car version, Tencent mini-scene and Apple CarPlay. The new car will also have intelligent laser headlights, Harman/Kardon high-end audio system, automatic parking assistance system Plus with 360 panoramic parking images, active cruise control system, forward collision warning and emergency braking assistance, lane rectification assistance, etc. (some of them are equipped with M50 version).

　　In the power system, i4 eDrive40 is a single motor, with a maximum power of 250kW(340 HP), a peak torque of 420 Nm, an acceleration time of 5.7 seconds at 0-100km/h and a cruising range of 625 km under CLTC standards. The maximum power of the dual motors on the i4 M50 is 400kW(544 HP), the peak torque is 795 Nm, the 0-100km/h acceleration time is 3.9 seconds, and the maximum cruising range of the vehicle under CLTC standard is 560 km. (Text/car home Chen Hao)