p*****e
发帖数: 290 | 1 Other and past predictions:
Biomolecular motors: Vale, Sheetz, Spudich, Brady
Unfolded protein response: Walter, Mori
Soft lithography and microfluidics: Whitesides, Quake
Chaperonins: Horwich, Hartl, Lindquist, Ellis
Polymers: Frechet, Matyjaszewski, Wang, Willson
Electrochemistry/bioinorganic: Bard, Gray, Lippard
Single-molecule spectroscopy: Moerner, Orrit
Solar: Grätzel, Nocera
DNA synthesis: Caruthers
Next-gen sequencing: Webb, Craighead, Klenerman, Church …
Super-resolution optical mi... 阅读全帖 |
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S*****n
发帖数: 6055 | 2 I am listing my answers to the differences b/w gasoline and diesel powered
vehicles. I hoped to get more input but unfortunately did not see much.
Anyway I will offer baozi to the first 3 IDs who tried to answer.
1. Composition: the molecular weight of gasoline (C5-C9) is lower than
diesel (C9-C18). So in gasoline we use octane number but in diesel we use
cetane number. They both contain alkanes, alkenes (refineries try to reduce
alkenes), cyclics and aromatics. Alkanes (including cycloalkanes) ... 阅读全帖 |
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l**********n
发帖数: 5272 | 4 多谢了。
刚古狗了一下，汽油长期存放会变质，氧化分解出有害物质， Stabilizer这东西可以
有助于保鲜、抵消氧化分解的有害物质、清洁油路。
下面拷贝自wiki.
Fuel stabilizers (antioxidants and metal deactivator)
Substituted phenols and derivatives of phenylenediamine are common
antioxidants used to inhibit gum formation in gasoline (gasoline).
Gummy, sticky resin deposits result from oxidative degradation of gasoline
upon long term storage. These harmful deposits arise from the oxidation of
alkenes and other minor components in gasoline (see drying oils).
Improvements... 阅读全帖 |
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s******g
发帖数: 2230 | 6 alkene不会出0.5的， likely something added to double bond
同学， 4.7是多少， 4.65还是4.74? 两个峰距离是多少hz， 你让人没法算呀。 这是
氢谱， 不是碳谱。 |
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n*****g
发帖数: 4117 | 7 ☆─────────────────────────────────────☆
axin (Axin) 于 (Sat May 9 02:44:03 2009) 提到:
stability order of alkenes 里面讲越多substitute, 分子越稳定。
讲原因的时候，提到MO 理论，hyperconjugation grouping,every C=C has an empty
p antibonding orbital, 我一直理解为 C=C bond can only have eiher bonding p
or nonbonding p orbital. because when they have the same sign, they form
bonding p; opisite sign, nonbonding p.
难道是c=c 加一起bonding and nonbonding 各一个么？
书上讲的很少，也不影响做题考试，就是很好奇想知道。
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sleepi |
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n*****g
发帖数: 4117 | 8 ☆─────────────────────────────────────☆
choubaoben (fancy) 于 (Wed May 20 00:30:45 2009) 提到:
很简单的底物olefin，dichloromethane做溶剂，-78oC 通ozone gas，（通的稍微有点
久，原料消耗完，又通了半个小时），然后加 dimethyl sulfide。
后来分离的结果有aldehyede 生成，但是还有另外一个点，在5.4 ppm 和 5.1 ppm附近
有峰，但肯定不是原料。
那位大虾对ozonolysis的副产物有概念的呢？
（尽管我很穷，不过还是尽力给包子），谢谢大家。
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choubaoben (fancy) 于 (Wed May 20 00:52:03 2009) 提到:
没人回答？ 顶一下
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echfour (h4) 于 (Wed May 20 01:23:18 2009) |
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s***o
发帖数: 58 | 9 Tetrahedron, 48(22), 4623-8; 1992
Convenient methods for the reduction of amides, nitriles, carboxylic esters,
acids and hydroboration of alkenes using the sodium borohydride-iodine
system |
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s**********r
发帖数: 67 | 10 1.
Title: Photosensitized oxidation of alkenes with dendrimers as microreactors
Author(s): Yuan Z, Zheng SJ, Zeng Y, et al.Source: NEW JOURNAL OF CHEMISTRY
Volume: 34 Issue: 4 Pages: 718-722 Published: 2010
2.
Title: A novel elsinochrome A derivative: a study of drug delivery and
photodynamic activity
Author(s): Zhang Y, Xie J, Zhang LY, et al.Source: PHOTOCHEMICAL &
PHOTOBIOLOGICAL SCIENCES Volume: 8 Issue: 12 Pages: 1676-1682
Published: 2009
3.
Title: Photobleaching of hypocrel... 阅读全帖 |
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m*****e
发帖数: 1506 | 11 Catalytic conversion of biomass to monofunctional hydrocarbons and targeted
liquid-fuel classes
作者: Kunkes Edward L.; Simonetti Dante A.; West Ryan M.; 等.
来源出版物: SCIENCE 卷: 322 期: 5900 页: 417-421 DOI: 10.1126/science
.1159210 出版年: OCT 17 2008
Renewable Chemical Commodity Feedstocks from Integrated Catalytic Processing
of Pyrolysis Oils
作者: Vispute Tushar P.; Zhang Huiyan; Sanna Aimaro; 等.
来源出版物: SCIENCE 卷: 330 期: 6008 页: 1222-1227 DOI: 10.1126/
science.1194218 出版年: NOV 26 2010
... 阅读全帖 |
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l**b
发帖数: 21 | 12 1.
Drozd, GT; Kroll, J; Donahue, NM. 2,3-Dimethyl-2-butene (TME) Ozonolysis:
Pressure Dependence of Stabilized Criegee Intermediates and Evidence of
Stabilized Vinyl Hydroperoxides. JOURNAL OF PHYSICAL CHEMISTRY A, 2011, 115
(2), 161-166.
http://pubs.acs.org/doi/abs/10.1021/jp108773d
2.
Drozd, GT, Donahue, NM. Pressure Dependence of Stabilized Criegee
Intermediate Formation from a Sequence of Alkenes. JOURNAL OF PHYSICAL
CHEMISTRY A, 2011, 115 (17), 4381-4387.
http://pubs.acs.org/doi/abs/10.1021... 阅读全帖 |
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s*******w
发帖数: 1879 | 13 Synthesis of 1,3-Dioxin-4-ones Unsubstituted at the 5- and 6-Positions and
Their Photoaddition to Alkenes
Sato, Masayuki; Ogasawara, Hiromichi; Sekiguchi, Keiko; Kaneko, Chikara
Heterocycles， Volume 22，Issue 11，Pages 2563-70， 1984
CODEN: HTCYAM
ISSN: 0385-5414
谢谢． |
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R******d
发帖数: 5739 | 14 I think the sulfur attacks the alkene on the maleic anhydride by free
radical? is it a linker? |
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m*****e
发帖数: 1506 | 16 Click chemistry已经热了好长时间，除了【3+2】外，进来Hawker推广了thio-ene 【
RSH + alkene, UV】 photo click chemistry。请牛人评价一下这类反应以及其应用前
景。 |
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a****d
发帖数: 524 | 17 长链 1-alkene 的AIBN homo-聚合，应该是很简单的聚合可是怎么也聚合不起来呢，
200：1，
100 度， 是自由基和单体比例太高？ 还是温度有点稍高？还是单体本身聚合活性太差
？ 本来挺简单
的聚合啊～～请有经验的给点clue ～～谢谢 |
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m*****e
发帖数: 1506 | 18 1-alkene是non-active单体，能自由基自聚就奇怪了，就是与活性单体共聚，转化率和
引入率也都很低。 |
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D********g
发帖数: 533 | 19 如果你功能团无所谓，那么就有很多反应效率很高的组合，比如
1. epoxy / amine
2. thiol / alkene
3. -COCl / -OH
4. Azide / Alkyne
等等 |
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