Changsha mail processing center can go by itself
For example, the hydrolysis of chlorotert butane can be carried out in two steps:
(CH3) 3ccl → (CH3) 3C + + Cl -
(CH3) 3C + + H2O → (CH3) 3coh + H +
two transition states and one intermediate, positive carbon ion (CH3) 3C +, appear between them. The two reactions pass through two barriers respectively Δ E1 and Δ E2, transition state 1 - (CH3) 3C... Cl and transition state 2 - (CH3) 3C... Oh2 appear at the potential energy peak of each step respectively, while the active intermediate is in the valley between the two peaks. The structure and properties of the active intermediate and the two transition states are similar, but different. Generally, intermediates are very active and have a short life, but they are more stable than transition states, so their structures can be determined by various modern physical and chemical methods. The lower the potential energy of the intermediate between the two transition states, the more stable the intermediate is. Based on the knowledge of the structure and properties of intermediates, the structure and properties of the transition state can be roughly deced to elucidate the reaction mechanism
if you want methyl to capture an oxygen atom in ozone, you need to make the captured oxygen atom close to the carbon atom of methyl and keep the captured oxygen atom away from the original structure of ozone. In other words, an oxygen atom is between the methyl group and the oxygen molecule
H3C... O... O2 is like this. The distance between atoms needs to be adjusted several times
first try MP2 / 6-31G (d) opt (TS, calcfc, maxcyc = 200, nosymm) freq = noraman.
Kunming is divided into Wuhua, Panlong, Guan and Xishan.
Dayu park is located in the north of Yihe community, Yupu Road, Chenggong County, Kunming City, which is a good place for entertainment and vacation. Dayu park is also a wedding photography Town, with flowers and love as the main design line, European architecture, small train, Dutch windmill, hot air balloon and so on, combining architecture and landscape
this park is especially suitable for taking photos and recording your best time. It is far away from the hustle and bustle of the city and is full of mystery and romance. Dayu park is like a fairy tale Town, with blue and white love sea, simple color and simple combination, but full of dreaminess
Wujiatang Wetland Park is located in Liujia Township and Xiaobanqiao of Guan town, mainly composed of water surface, beach and swamp, covering an area of about 1300 mu, which is equivalent to the size of four Cuihu parks. Wujiatang Wetland Park is the first wetland park in Kunming. Dianchi Lake reappeared in the past barren beach; Green feather Danxia, three spring willow, nine summer Hibiscus & quot; The beauty of the world There are abundant animals and plants in Wujiatang Wetland Park. In the park with warm spring and few people, walking and riding are good ways to relax. In Wujiatang, you can see butterflies and flowers, listen to insects and birds, feel the breath of wetland sponge, and have a unique flavor of Kunming. It's pleasant and comfortable with the breeze
3. Guan ancient town has rich and long history, which is one of the famous historical and cultural ancient towns in Kunming. There are many cultural relics and rich cultural landscapes in the ancient town. In less than 1.5 square kilometers, there are five mountains, six temples, seven pavilions and Eight Temples in Tang, song, yuan, Ming and Qing Dynasties. Walking through this ancient town with many streets, time can be slowed down
now Guan ancient town is graally renovating its traditional dwellings and carrying out planned protection. What we will see in the future is an old and young new Guan with a long and splendid history and a glorious future
What's unforgettable here is the taste of delicious food. Guan Baba, papaya water, fried potato, & quot; Urine & quot; Pickled cabbage, cold noodles with sesame sauce, chicken feet Baijiu, small bean pot, rice noodle, chicken feet, sweet liquor, grasping powder,
9, Dou Nan flower market
, flowers in Kunming, it is definitely the flower market of Dou Nan, and Dou Nan has become the "vane" of China's flower market and the barometer of flower prices. In the market, everyone, flowers, so harmonious, probably no place, like Kunming, flowers so cheap
AAC is a kind of audio compression method, because the audio part on CD, DVD and other discs is in the form of data stream, there are many restrictions on using player or playing software to play (a few years ago, if there was no optical drive, it could not play). In order to solve this problem, someone developed the audio compression method. At first, it was MP3. Later, because the sound quality of MP3 was too poor, they developed the AAC compression method. The sound quality was much better than MP3. However, although there are many big brand support, because it is still a way of lossy compression, it is not very optimistic. At present, ape and FLAC are the mainstream of lossless compression, and their sound quality is not comparable to AAC. It's just that the file capacity is larger, but because of the popularity of mass storage chips, this is no longer a problem
as for AC-3, it is a multi-channel digital audio system launched by Dolby lab. The surround sound system provided by AC-3 consists of five full frequency channels and one subwoofer channel, so it is called 5.1 channels. The five channels include & quot; Left channel& quot; Middle channel& quot; Right channel Post & quot; Left surround channel & quot; And & quot; Right surround channel & quot;. The frequency range of these channels is 3-20000 Hz. The sixth channel, that is, the subwoofer channel, contains some extra bass information, which makes some scenes, such as explosions and bumps, more effective. Since the frequency response of this channel is 3-120hz, it is called & quot 1" Vocal tract. Of course, this kind of 5.1 audio system needs to be adopted from the live recording of the sound source, and a special decoder is also needed when playing. If you play it on the computer, you can also use the "DTS sound card" to do decoding, which can rece some costs. After all, a DTS sound card only costs more than 1000 yuan
to remind you: (if you already know it, you can ignore it) most of the so-called 2.1, 4.1 and 5.1 computer speakers we can buy in the electronic or computer market are junk procts. Only a few of the more expensive 2.1 sound quality can be said to be in the past, while 5.1 without American Dolby certification is only a of the shape, no decoding circuit, only relying on the computer output of the two channels randomly
I don't know if you have any misunderstandings or what you want to do, so I have to explain both and make your own judgment
AAC is only a compression method, not a coding method. AC3 format is to capture the AC-3 track in order to retain the file formed by AC-3 coding. Of course, you can convert the ordinary audio file into AC3 file through the conversion software. However, not only the source file is greatly damaged, but the effect of AC-3 can only be regarded as bullshit! After all, it's not that Dolby lab was paid for the usage fee, and AC-3 coding was used when recording the audio signal (ring shooting).
2012-05-19 15:00:06 Nanxiaojie delivery destination --- Changsha County, Changsha City, Hunan Province
2012-05-19 18:31:00 Xining City arrival processing center
2012-05-21 23:51:00 Wuhan Central Bureau arrival processing center
2012-05-23 08:44:00 Changsha Central Bureau arrival processing center
this mail At present, there is no new information. You call customer service at 11185 to ask for a reply, but you can't get the mail when you go to the processing center, because the processing center is the mail sending and transferring department, and does not deliver the relevant mail to the outside.